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Sample records for sirtuin inhibitors synthesis

  1. Synergistic interactions between HDAC and sirtuin inhibitors in human leukemia cells.

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    Michele Cea

    Full Text Available Aberrant histone deacetylase (HDAC activity is frequent in human leukemias. However, while classical, NAD(+-independent HDACs are an established therapeutic target, the relevance of NAD(+-dependent HDACs (sirtuins in leukemia treatment remains unclear. Here, we assessed the antileukemic activity of sirtuin inhibitors and of the NAD(+-lowering drug FK866, alone and in combination with traditional HDAC inhibitors. Primary leukemia cells, leukemia cell lines, healthy leukocytes and hematopoietic progenitors were treated with sirtuin inhibitors (sirtinol, cambinol, EX527 and with FK866, with or without addition of the HDAC inhibitors valproic acid, sodium butyrate, and vorinostat. Cell death was quantified by propidium iodide cell staining and subsequent flow-cytometry. Apoptosis induction was monitored by cell staining with FITC-Annexin-V/propidium iodide or with TMRE followed by flow-cytometric analysis, and by measuring caspase3/7 activity. Intracellular Bax was detected by flow-cytometry and western blotting. Cellular NAD(+ levels were measured by enzymatic cycling assays. Bax was overexpressed by retroviral transduction. Bax and SIRT1 were silenced by RNA-interference. Sirtuin inhibitors and FK866 synergistically enhanced HDAC inhibitor activity in leukemia cells, but not in healthy leukocytes and hematopoietic progenitors. In leukemia cells, HDAC inhibitors were found to induce upregulation of Bax, a pro-apoptotic Bcl2 family-member whose translocation to mitochondria is normally prevented by SIRT1. As a result, leukemia cells become sensitized to sirtuin inhibitor-induced apoptosis. In conclusion, NAD(+-independent HDACs and sirtuins cooperate in leukemia cells to avoid apoptosis. Combining sirtuin with HDAC inhibitors results in synergistic antileukemic activity that could be therapeutically exploited.

  2. Carprofen analogues as sirtuin inhibitors: enzyme and cellular studies.

    Science.gov (United States)

    Mellini, Paolo; Carafa, Vincenzo; Di Rienzo, Barbara; Rotili, Dante; De Vita, Daniela; Cirilli, Roberto; Gallinella, Bruno; Provvisiero, Donatella Paola; Di Maro, Salvatore; Novellino, Ettore; Altucci, Lucia; Mai, Antonello

    2012-11-01

    The best of both: SIRT1/2 inhibitors were developed by combining chemical features of selisistat (SIRT1-selective inhibitor; blue) and carprofen (anti-inflammatory drug; red). The most potent compound (shown) increased acetyl-p53 and acetyl-α-tubulin levels, and induced slight apoptosis at 50 μM in U937 cells, differently from selisistat and carprofen. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The Sirtuin 2 Inhibitor AK-7 Is Neuroprotective in Huntington’s Disease Mouse Models

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    Vanita Chopra

    2012-12-01

    Full Text Available Inhibition of sirtuin 2 (SIRT2 deacetylase mediates protective effects in cell and invertebrate models of Parkinson’s disease and Huntington’s disease (HD. Here we report the in vivo efficacy of a brain-permeable SIRT2 inhibitor in two genetic mouse models of HD. Compound treatment resulted in improved motor function, extended survival, and reduced brain atrophy and is associated with marked reduction of aggregated mutant huntingtin, a hallmark of HD pathology. Our results provide preclinical validation of SIRT2 inhibition as a potential therapeutic target for HD and support the further development of SIRT2 inhibitors for testing in humans.

  4. Structural Modifications of Benzimidazoles via Multi-Step Synthesis and Their Impact on Sirtuin-Inhibitory Activity.

    Science.gov (United States)

    Yoon, Yeong Keng; Choon, Tan Soo

    2016-01-01

    Benzimidazole derivatives have been shown to possess sirtuin-inhibitory activity. In the continuous search for potent sirtuin inhibitors, systematic changes on the terminal benzene ring were performed on previously identified benzimidazole-based sirtuin inhibitors, to further investigate their structure-activity relationships. It was demonstrated that the sirtuin activities of these novel compounds followed the trend where meta-substituted compounds possessed markedly weaker potency than ortho- and para-substituted compounds, with the exception of halogenated substituents. Molecular docking studies were carried out to rationalize these observations. Apart from this, the methods used to synthesize the interesting compounds are also discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Antitumor effects of a sirtuin inhibitor, tenovin-6, against gastric cancer cells via death receptor 5 up-regulation.

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    Sachiko Hirai

    Full Text Available Up-regulated sirtuin 1 (SIRT1, an NAD+-dependent class III histone deacetylase, deacetylates p53 and inhibits its transcriptional activity, leading to cell survival. SIRT1 overexpression has been reported to predict poor survival in some malignancies, including gastric cancer. However, the antitumor effect of SIRT1 inhibition remains elusive in gastric cancer. Here, we investigated the antitumor mechanisms of a sirtuin inhibitor, tenovin-6, in seven human gastric cancer cell lines (four cell lines with wild-type TP53, two with mutant-type TP53, and one with null TP53. Interestingly, tenovin-6 induced apoptosis in all cell lines, not only those with wild-type TP53, but also mutant-type and null versions, accompanied by up-regulation of death receptor 5 (DR5. In the KatoIII cell line (TP53-null, DR5 silencing markedly attenuated tenovin-6-induced apoptosis, suggesting that the pivotal mechanism behind its antitumor effects is based on activation of the death receptor signal pathway. Although endoplasmic reticulum stress caused by sirtuin inhibitors was reported to induce DR5 up-regulation in other cancer cell lines, we could not find marked activation of its related molecules, such as ATF6, PERK, and CHOP, in gastric cancer cells treated with tenovin-6. Tenovin-6 in combination with docetaxel or SN-38 exerted a slight to moderate synergistic cytotoxicity against gastric cancer cells. In conclusion, tenovin-6 has potent antitumor activity against human gastric cancer cells via DR5 up-regulation. Our results should be helpful for the future clinical development of sirtuin inhibitors.

  6. Chemical probing of the human sirtuin 5 active site reveals its substrate acyl specificity and peptide-based inhibitors.

    Science.gov (United States)

    Roessler, Claudia; Nowak, Theresa; Pannek, Martin; Gertz, Melanie; Nguyen, Giang T T; Scharfe, Michael; Born, Ilona; Sippl, Wolfgang; Steegborn, Clemens; Schutkowski, Mike

    2014-09-26

    Sirtuins are NAD(+)-dependent deacetylases acting as sensors in metabolic pathways and stress response. In mammals there are seven isoforms. The mitochondrial sirtuin 5 is a weak deacetylase but a very efficient demalonylase and desuccinylase; however, its substrate acyl specificity has not been systematically analyzed. Herein, we investigated a carbamoyl phosphate synthetase 1 derived peptide substrate and modified the lysine side chain systematically to determine the acyl specificity of Sirt5. From that point we designed six potent peptide-based inhibitors that interact with the NAD(+) binding pocket. To characterize the interaction details causing the different substrate and inhibition properties we report several X-ray crystal structures of Sirt5 complexed with these peptides. Our results reveal the Sirt5 acyl selectivity and its molecular basis and enable the design of inhibitors for Sirt5. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Benzoylurea Chitin Synthesis Inhibitors.

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    Sun, Ranfeng; Liu, Chunjuan; Zhang, Hao; Wang, Qingmin

    2015-08-12

    Benzoylurea chitin synthesis inhibitors are widely used in integrated pest management (IPM) and insecticide resistance management (IRM) programs due to their low toxicity to mammals and predatory insects. In the past decades, a large number of benzoylurea derivatives have been synthesized, and 15 benzoylurea chitin synthesis inhibitors have been commercialized. This review focuses on the history of commercial benzolyphenylureas (BPUs), synthetic methods, structure-activity relationships (SAR), action mechanism research, environmental behaviors, and ecotoxicology. Furthermore, their disadvantages of high risk to aquatic invertebrates and crustaceans are pointed out. Finally, we propose that the para-substituents at anilide of benzoylphenylureas should be the functional groups, and bipartite model BPU analogues are discussed in an attempt to provide new insight for future development of BPUs.

  8. A Continuous, Fluorogenic Sirtuin 2 Deacylase Assay

    DEFF Research Database (Denmark)

    Galleano, Iacopo; Schiedel, Matthias; Jung, Manfred

    2016-01-01

    and kinetic insight regarding sirtuin inhibitors, it is important to have access to efficient assays. In this work, we report readily synthesized fluorogenic substrates enabling enzyme-economical evaluation of SIRT2 inhibitors in a continuous assay format as well as evaluation of the properties of SIRT2...

  9. Mechanism-based Inhibitors of the Human Sirtuin 5 Deacylase: Structure-Activity Relationship, Biostructural, and Kinetic Insight

    DEFF Research Database (Denmark)

    Rajabi, Nima; Auth, Marina; Troelsen, Kathrin Rentzius

    2017-01-01

    to date. We provide rationalization of the mode of binding by solving co-crystal structures of selected inhibitors in complex with both human and zebrafish SIRT5, which provide insight for future optimization of inhibitors with more "drug-like" properties. Importantly, enzyme kinetic evaluation revealed...

  10. The sirtuin 1/2 inhibitor tenovin-1 induces a nonlinear apoptosis-inducing factor-dependent cell death in a p53 null Ewing's sarcoma cell line.

    Science.gov (United States)

    Marx, Christian; Marx-Blümel, Lisa; Lindig, Nora; Thierbach, René; Hoelzer, Doerte; Becker, Sabine; Wittig, Susan; Lehmann, Roland; Slevogt, Hortense; Heinzel, Thorsten; Wang, Zhao-Qi; Beck, James F; Sonnemann, Jürgen

    2018-06-01

    The sirtuin 1/2 inhibitor tenovin-1 activates p53 and may have potential in the management of cancer. Here, we investigated the responsiveness of Ewing's sarcoma cells to tenovin-1. We examined its effects in two Ewing's sarcoma cell lines with different p53 status, i.e. in p53 wild-type and p53 null cells. Effects were assessed by flow cytometric analyses of cell death, mitochondrial membrane depolarization and reactive oxygen species (ROS) generation, by caspase 3/7 activity measurement, by mRNA expression profiling and by immunoblotting. Tenovin-1 elicited caspase-mediated cell death in p53 wild-type cells, but caspase-independent cell death in p53 null cells. Remarkably, it induced a nonlinear concentration response in the latter: low concentrations of tenovin-1 were much more effective than were higher concentrations. Tenovin-1's effects in p53 null cells involved gene expression changes of Bcl-2 family members, mitochondrial membrane depolarization, nuclear translocation of apoptosis-inducing factor, ROS formation and DNA damage; all these effects followed a bell-shaped pattern. In conclusion, our results provide new insights into tenovin-1's mode of action by demonstrating that it can induce different pathways of cell death.

  11. Sirtuins & disease: the road ahead

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    Vincenzo eCarafa

    2012-01-01

    Full Text Available Sirtuins represent a promising new class of conserved histone deacetylases, originally identified in yeast. The activity of the sirtuin (SirT family – made up of seven members (SirT1-7 – is NAD+ dependent. Sirtuins target a wide range of cellular proteins in nucleus, cytoplasm and mitochondria for post-translational modification by acetylation (SirT1, 2, 3 and 5 or ADP ribosylation (SirT4 and 6. Sirtuins regulate responses to stress and ensure that damaged DNA is not propagated, thus contrasting the accumulation of mutations. To date, sirtuins have emerged as potential therapeutic targets for treatment of human pathologies such as metabolic, cardiovascular and neurodegenerative diseases, and cancer. SirT1 is the founding member of this class of enzymes and is currently the best known of the group. SirT1 acts in various cellular processes, deacetylating both chromatin and non-histone proteins, and its role in cancer and aging has been extensively studied. SirT1 may play a critical role in tumor initiation and progression as well as drug resistance by blocking senescence and apoptosis, and by promoting cell growth and angiogenesis. Recently, growing interest in sirtuin modulation has led to the discovery and characterization of small molecules able to modify sirtuin activity. The present review highlights SirT mechanism(s of action and deregulation in cancer, focusing on the therapeutic potential of SirT modulators both in cancer prevention and treatment.

  12. Rapid synthesis of triazine inhibitors of inosine monophosphate dehydrogenase.

    Science.gov (United States)

    Pitts, William J; Guo, Junqing; Dhar, T G Murali; Shen, Zhongqi; Gu, Henry H; Watterson, Scott H; Bednarz, Mark S; Chen, Bang Chi; Barrish, Joel C; Bassolino, Donna; Cheney, Daniel; Fleener, Catherine A; Rouleau, Katherine A; Hollenbaugh, Diane L; Iwanowicz, Edwin J

    2002-08-19

    A series of novel triazine-based small molecule inhibitors (IV) of inosine monophosphate dehydrogenase was prepared. The synthesis and the structure-activity relationships (SAR) derived from in vitro studies are described.

  13. Synthesis of Novel Chalcones as Acetylcholinesterase Inhibitors

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    Thanh-Dao Tran

    2016-07-01

    Full Text Available A new series of benzylaminochalcone derivatives with different substituents on ring B were synthesized and evaluated as inhibitors of acetylcholinesterase. The study is aimed at identification of novel benzylaminochalcones capable of blocking acetylcholinesterase activity for further development of an approach to Alzheimer’s disease treatment. These compounds were produced in moderate to good yields via Claisen-Schmidt condensation and subjected to an in vitro acetylcholinesterase inhibition assay, using Ellman’s method. The in silico docking procedure was also employed to identify molecular interactions between the chalcone compounds and the enzyme. Compounds with ring B bearing pyridin-4-yl, 4-nitrophenyl, 4-chlorophenyl and 3,4-dimethoxyphenyl moieties were discovered to exhibit significant inhibitory activities against acetylcholinesterase, with IC50 values ranging from 23 to 39 µM. The molecular modeling studies are consistent with the hypothesis that benzylaminochalcones could exert their effects as dual-binding-site acetylcholinesterase inhibitors, which might simultaneously enhance cholinergic neurotransmission and inhibit β-amyloid aggregation through binding to both catalytic and peripheral sites of the enzyme. These derivatives could be further developed to provide novel leads for the discovery of new anti-Alzheimer drugs in the future.

  14. Synthesis and Application of Pyrrolidone-containing Shale Inhibitors

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    Liu, Yonggui; Hou, Jie; Zhang, Yang; Yan, Jing; Song, Tao; Xu, Yongjun

    2018-03-01

    New generation polyamine inhibitors are amino-terminated polyethers with excellent inhibiting capabilities; they play a key role in borehole stabilization and reservoir protection. However, polyamine inhibitors are limited by their poor thermal stability, which can be attributed to the presence of ether bonds in their molecular structures. We propose a three-step synthesis approach fora novel pyrrolidone-containing polyamine inhibitor (DYNP) by introducing N-vinyl-2-pyrrolidone (NVP) on divinyloxyethane. This polyamine inhibitor exhibits an optimized molecular structure and has enhanced heat resistance. Characterizations by infrared (IR) spectroscopy and evaluation tests demonstrate several advantages of DYNP inhibitors, including excellent inhibiting capability (superior to similar materials such as polyamines), improved heat resistance (reasonable stability at temperatures up to 240°C), and good compatibility with both fresh water and salt water drilling fluids. These can be attributed to the presence of considerable amounts of amino groups in the repeating unit of DYNP molecules. The DYNP inhibitor was applied in over 20 boreholes in tight oil blocks in Daqing Oilfield to relieve hydration of formations with high shale contents. For instance, drilling in the 2033.5m horizontal section of Dragon 2 borehole was smooth, with a borehole diameter expansion ratio below 10%.

  15. Synthesis of tritium labeled renin inhibitor ditekiren

    International Nuclear Information System (INIS)

    Hsi, R.S.P.; Stolle, W.T.; Bundy, G.L.

    1994-01-01

    In the search for a radioactive form of the peptidomimetic renin inhibitor, ditekiren, with a metabolically suitable radiolabel for conducting drug disposition studies, we prepared [ 3 H]ditekiren with tritium labels in the N-methyl-histidine moiety and in the leu-val alcohol transition-state insert. [His- 3 H]ditekiren was obtained by first introducing two iodine substituents into the N-methyl-histidine moiety of the parent drug, followed by catalytic hydrodehalogenation with tritium gas. Administration of this labeled drug to monkeys, however, resulted in prolonged retention of radioactivity in the test animals, even though little or no tritiated water was detected in urine. The results, together with similar earlier findings after administration of [ 3 H]ditekiren labeled in the proline moiety of the drug, led us to synthesize [ 3 H]ditekiren labeled in the ''unnatural'' leu-val alcohol (LVA) portion of the molecule. The tritium label in [LVA- 3 H]ditekiren was found to be metabolically suitable for conducting drug disposition studies, with no liability for tritiated water production or prolonged retention of radioactivity in tissues of test animals. (author)

  16. Sirtuin inhibition attenuates the production of inflammatory cytokines in lipopolysaccharide-stimulated macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Claudia A. [Universite catholique de Louvain, Louvain Drug Research Institute (LDRI), Pharmaceutics and Drug Delivery Research Group, Brussels B-1200 (Belgium); Fievez, Laurence [University of Liege, GIGA-Research, Laboratory of Cellular and Molecular Immunology, Liege B-4000 (Belgium); Neyrinck, Audrey M.; Delzenne, Nathalie M. [Universite catholique de Louvain, LDRI, Metabolism and Nutrition Research Group, Brussels B-1200 (Belgium); Bureau, Fabrice [University of Liege, GIGA-Research, Laboratory of Cellular and Molecular Immunology, Liege B-4000 (Belgium); Vanbever, Rita, E-mail: rita.vanbever@uclouvain.be [Universite catholique de Louvain, Louvain Drug Research Institute (LDRI), Pharmaceutics and Drug Delivery Research Group, Brussels B-1200 (Belgium)

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer Lipopolysaccharide-stimulated macrophages were treated with cambinol and sirtinol. Black-Right-Pointing-Pointer Cambinol and sirtinol decreased lipopolysaccharide-induced cytokines. Black-Right-Pointing-Pointer Cambinol decreased NF-{kappa}B activity but had no impact on p38 MAPK activation. Black-Right-Pointing-Pointer Sirtuins are an interesting target for the treatment of inflammatory diseases. -- Abstract: In several inflammatory conditions such as rheumatoid arthritis or sepsis, the regulatory mechanisms of inflammation are inefficient and the excessive inflammatory response leads to damage to the host. Sirtuins are class III histone deacetylases that modulate the activity of several transcription factors that are implicated in immune responses. In this study, we evaluated the impact of sirtuin inhibition on the activation of lipopolysaccharide (LPS)-stimulated J774 macrophages by assessing the production of inflammatory cytokines. The pharmacologic inhibition of sirtuins decreased the production of tumour necrosis factor-alpha (TNF-{alpha}) interleukin 6 (IL-6) and Rantes. The reduction of cytokine production was associated with decreased nuclear factor kappa B (NF-{kappa}B) activity and inhibitor kappa B alpha (I{kappa}B{alpha}) phosphorylation while no impact was observed on the phosphorylation status of p38 mitogen-activated kinase (p38 MAPK). This work shows that sirtuin pharmacologic inhibitors are a promising tool for the treatment of inflammatory conditions.

  17. Sirtuin inhibition attenuates the production of inflammatory cytokines in lipopolysaccharide-stimulated macrophages

    International Nuclear Information System (INIS)

    Fernandes, Cláudia A.; Fievez, Laurence; Neyrinck, Audrey M.; Delzenne, Nathalie M.; Bureau, Fabrice; Vanbever, Rita

    2012-01-01

    Highlights: ► Lipopolysaccharide-stimulated macrophages were treated with cambinol and sirtinol. ► Cambinol and sirtinol decreased lipopolysaccharide-induced cytokines. ► Cambinol decreased NF-κB activity but had no impact on p38 MAPK activation. ► Sirtuins are an interesting target for the treatment of inflammatory diseases. -- Abstract: In several inflammatory conditions such as rheumatoid arthritis or sepsis, the regulatory mechanisms of inflammation are inefficient and the excessive inflammatory response leads to damage to the host. Sirtuins are class III histone deacetylases that modulate the activity of several transcription factors that are implicated in immune responses. In this study, we evaluated the impact of sirtuin inhibition on the activation of lipopolysaccharide (LPS)-stimulated J774 macrophages by assessing the production of inflammatory cytokines. The pharmacologic inhibition of sirtuins decreased the production of tumour necrosis factor-alpha (TNF-α) interleukin 6 (IL-6) and Rantes. The reduction of cytokine production was associated with decreased nuclear factor kappa B (NF-κB) activity and inhibitor kappa B alpha (IκBα) phosphorylation while no impact was observed on the phosphorylation status of p38 mitogen-activated kinase (p38 MAPK). This work shows that sirtuin pharmacologic inhibitors are a promising tool for the treatment of inflammatory conditions.

  18. A practical synthesis of a gamma-secretase inhibitor.

    Science.gov (United States)

    Scott, Jeremy P; Lieberman, David R; Beureux, Olivier M; Brands, Karel M J; Davies, Antony J; Gibson, Andrew W; Hammond, Deborah C; McWilliams, Chris J; Stewart, Gavin W; Wilson, Robert D; Dolling, Ulf-H

    2007-05-25

    A practical and scaleable synthesis of the gamma-secretase inhibitor 1 is reported. The inhibitor consists of a central trisubstituted cyclohexane core with appended propionic acid, 2,5-difluorophenyl, and 4-chlorophenylsulfonyl moieties. Two alternative synthetic strategies, proceeding by way of a common disubstituted cyclohexanone derivative 5, were studied. In the preferred route, conjugate reduction of acrylonitrile derivative 4 with L-Selectride configures the desired relative stereochemistry of the cyclohexane core with >99.9:0.1 dr. A second strategy, based on catalyst-controlled hydrogenation of racemic cyclohexene derivative 2, is more convergent but less diastereoselective (up to 75:25 dr). The common cyclohexanone intermediate 5 was constructed by a regioselective Diels-Alder condensation of a 1,1-disubstituted vinyl sulfone 6 with 2-trimethylsiloxybutadiene.

  19. The sirtuins: Markers of metabolic health.

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    Covington, Jeffrey D; Bajpeyi, Sudip

    2016-01-01

    The sirtuins represent a class of proteins first discovered orthologus to the yeast silent information regulator 2 protein that have been retained in mammalian species. Currently, seven sirtuins have been identified in humans, and their functions currently surpass their originally identified role as histone deacetylase and chromatin silencers to encompass nutrient sensing and metabolic function. All seven sirtuins require NAD(+) in order to carry out their enzymatic activity, and thus become activated in conditions of nutrient depletion, starvation, and cellular stress. Caloric restriction and increased physical activity have been postulated, though perhaps controversially, to mediate sirtuin function. Here, we review the current literature surrounding the functions of the seven human sirtuins, mediators of their function, and the roles they play in metabolic health related to dietary and physical activity interventions. Despite the controversy surrounding sirtuin function with regard to longevity, we have aimed to show that regardless of its effects on aging, sirtuin function is pivotal to pathways involving metabolic health, and should therefore be investigated with regard to improving metabolic diseases such as obesity and type 2 diabetes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Thromboxane synthesis inhibitors and postprandial jejunal capillary exchange capacity.

    Science.gov (United States)

    Mangino, M J; Chou, C C

    1988-05-01

    The effects of thromboxane synthesis inhibitors (imidazole and U 63557A; Upjohn) and the cyclooxygenase inhibitor, mefenamic acid, on jejunal capillary filtration coefficients (Kfc) were determined in dogs before and during the presence of predigested food in the jejunal lumen. The jejunal Kfc increased significantly soon after the placement of a predigested test food containing all major constituents of diet. The Kfc remained elevated as long as the food was present in the lumen (15 min). Mefenamic acid (10 mg/kg iv) did not significantly alter resting jejunal Kfc or alter the food-induced increase in Kfc. Imidazole (5.0 mg/min ia) or U 63557A (5.0 mg/kg iv) per se significantly increased jejunal Kfc. Placement of digested food further increased the Kfc to levels significantly higher than those observed before administration of the two thromboxane synthase inhibitors. Production of thromboxane B2 by jejunal tissue was significantly reduced and 6-ketoprostaglandin F1 alpha (the stable hydrolysis product of prostacyclin) production was significantly increased after administration of U 63557A. Our study indicates that the relative production of endogenous thromboxanes and other prostanoids modulates jejunal capillary exchange capacity in the absence or presence of digested food in the jejunal lumen.

  1. Effect of ketoconazole in combination with other inhibitors of sterol synthesis on fungal growth.

    OpenAIRE

    Sud, I J; Feingold, D S

    1985-01-01

    The effect of combination of ketoconazole with other sterol synthesis inhibitors on fungal growth was tested against a variety of fungi selected for resistance to ketoconazole. All of the sterol inhibitors, at concentrations lower than their MICs, caused an increase greater than fourfold in the ketoconazole susceptibility of some fungi. Some of the sterol synthesis inhibitors showed this effect with ketoconazole at levels that may be achieved clinically.

  2. Alterations of sirtuins in mitochondrial cytochrome c-oxidase deficiency.

    Directory of Open Access Journals (Sweden)

    Arne Björn Potthast

    Full Text Available Sirtuins are NAD+ dependent deacetylases, which regulate mitochondrial energy metabolism as well as cellular response to stress. The NAD/NADH-system plays a crucial role in oxidative phosphorylation linking sirtuins and the mitochondrial respiratory chain. Furthermore, sirtuins are able to directly deacetylate and activate different complexes of the respiratory chain. This prompted us to analyse sirtuin levels in skin fibroblasts from patients with cytochrome c-oxidase (COX deficiency and to test the impact of different pharmaceutical activators of sirtuins (SRT1720, paeonol to modulate sirtuins and possibly respiratory chain enzymes in patient cells in vitro.We assayed intracellular levels of sirtuin 1 and the mitochondrial sirtuins SIRT3 and SIRT4 in human fibroblasts from patients with COX- deficiency. Furthermore, sirtuins were measured after inhibiting complex IV in healthy control fibroblasts by cyanide and after incubation with activators SRT1720 and paeonol. To determine the effect of sirtuin inhibition at the cellular level we measured total cellular acetylation (control and patient cells, with and without treatment by Western blot.We observed a significant decrease in cellular levels of all three sirtuins at the activity, protein and transcriptional level (by 15% to 50% in COX-deficient cells. Additionally, the intracellular concentration of NAD+ was reduced in patient cells. We mimicked the biochemical phenotype of COX- deficiency by incubating healthy fibroblasts with cyanide and observed reduced sirtuin levels. A pharmacological activation of sirtuins resulted in normalized sirtuin levels in patient cells. Hyper acetylation was also reversible after treatment with sirtuin activators. Pharmacological modulation of sirtuins resulted in altered respiratory chain complex activities.We found inhibition of situins 1, 3 and 4 at activity, protein and transcriptional levels in fibroblasts from patient with COX-deficiency. Pharmacological

  3. Inhibition of hydrogenase synthesis by DNA gyrase inhibitors in Bradyrhizobium japonicum

    International Nuclear Information System (INIS)

    Novak, P.D.; Maier, R.J.

    1987-01-01

    Derepression of an uptake hydrogenase in Bradyrhizobium japonicum is dependent on a microaerophilic environment. Addition of DNA gyrase inhibitors during derepression of hydrogenase specifically prevented expression of the hydrogenase enzyme. Antibodies to individual hydrogenase subunits failed to detect the protein after derepression in the presence of inhibitors, although there was no general inhibition of protein synthesis. The general pattern of proteins synthesized from 14 C-labeled amino acids during derepression was no significantly different whether proteins were labeled in the presence or in the absence of gyrase inhibitors. In contrast, if transcription or translation was inhibited by addition of inhibitors of those functions, virtually no proteins were labeled during derepression. This indicated that most of the 14 C-labeled proteins were synthesized de novo during derepression, synthesis of most proteins was unaffected by gyrase inhibitors, and the dependence of hydrogenase synthesis on gyrase activity was a specific one

  4. Enantioselective synthesis of the novel chiral sulfoxide derivative as a glycogen synthase kinase 3beta inhibitor.

    Science.gov (United States)

    Saitoh, Morihisa; Kunitomo, Jun; Kimura, Eiji; Yamano, Toru; Itoh, Fumio; Kori, Masakuni

    2010-09-01

    Glycogen synthase kinase 3beta (GSK-3beta) inhibitors are expected to be attractive therapeutic agents for the treatment of Alzheimer's disease (AD). Recently we discovered sulfoxides (S)-1 as a novel GSK-3beta inhibitor having in vivo efficacy. We investigated practical asymmetric preparation methods for the scale-up synthesis of (S)-1. The highly enantioselective synthesis of (S)-1 (94% ee) was achieved by titanium-mediated oxidation with D-(-)-diethyl tartrate on gram scale.

  5. 3-cyanoindole-based inhibitors of inosine monophosphate dehydrogenase: synthesis and initial structure-activity relationships.

    Science.gov (United States)

    Dhar, T G Murali; Shen, Zhongqi; Gu, Henry H; Chen, Ping; Norris, Derek; Watterson, Scott H; Ballentine, Shelley K; Fleener, Catherine A; Rouleau, Katherine A; Barrish, Joel C; Townsend, Robert; Hollenbaugh, Diane L; Iwanowicz, Edwin J

    2003-10-20

    A series of novel small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH), based upon a 3-cyanoindole core, were explored. IMPDH catalyzes the rate determining step in guanine nucleotide biosynthesis and is a target for anticancer, immunosuppressive and antiviral therapy. The synthesis and the structure-activity relationships (SAR), derived from in vitro studies, for this new series of inhibitors is given.

  6. Benzimidazoles as new scaffold of sirtuin inhibitors: green synthesis, in vitro studies, molecular docking analysis and evaluation of their anti-cancer properties.

    Science.gov (United States)

    Yoon, Yeong Keng; Ali, Mohamed Ashraf; Wei, Ang Chee; Shirazi, Amir Nasrolahi; Parang, Keykavous; Choon, Tan Soo

    2014-08-18

    Two series of novel benzimidazole derivatives were designed, synthesized and evaluated for their SIRT1 and SIRT2 inhibitory activity. Among the newly synthesized compounds, compound 4j displayed the best inhibitory activity for SIRT1 (IC50 = 54.21 μM) as well as for SIRT2 (IC50 = 26.85 μM). Cell proliferation assay showed that compound 4j possessed good antitumor activity against three different types of cancer cells derived from colon (HCT-116), breast (MDA-MB-468) and blood-leukemia (CCRF-CEM) with cell viability of 40.0%, 53.2% and 27.2% respectively at 50 μM. Docking analysis of representative compound 4j into SIRT2 indicated that the interaction with receptor was primarily due to hydrogen bonding and π-π stacking interactions. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. Selective inhibition of influenza virus protein synthesis by inhibitors of DNA function

    International Nuclear Information System (INIS)

    Minor, P.D.; Dimmock, N.J.

    1977-01-01

    Various known inhibitors of cellular DNA function were shown to inhibit cellular RNA synthesis and influenza (fowl plague) virus multiplication. The drugs were investigated for their effect upon the synthesis of influenza virus proteins. According to this effect they could be classified with previously studied compounds as follows: Group I (ethidium bromide, proflavine, and N-nitroquinoline-N-oxide) inhibited both viral and cellular protein synthesis; Group II (nogalomycin, daunomycin and α-amanitin) inhibited viral but not cellular protein synthesis, and all viral proteins were inhibited coordinately; Group III (mithramycin, echinomycin, and actinomycin D) inhibited all viral but not cellular protein synthesis at high concentrations, but at a lower critical concentration inhibited the synthesis of viral haemagglutinin, neuraminidase, and M protein preferentially; Group IV(uv irradiation and camptothecin) inhibited the synthesis of viral haemagglutinin, neuraminidase, and M protein, but not other viral proteins, even at high doses. The mode of action of these inhibitors is discussed in relation to the mechanism of the nuclear events upon which influenza virus multiplication is dependent

  8. Design, synthesis and biological activity of novel peptidyl benzyl ketone FVIIa inhibitors

    DEFF Research Database (Denmark)

    Storgaard, Morten; Henriksen, Signe Teuber; Zaragoza, Florencio

    2011-01-01

    Herein is described the synthesis of a novel class of peptidyl FVIIa inhibitors having a C-terminal benzyl ketone group. This class is designed to be potentially suitable as stabilization agents of liquid formulations of rFVIIa, which is a serine protease used for the treatment of hemophilia...

  9. Synthesis and evaluation of iodide uptake inhibitors in thyroid gland

    International Nuclear Information System (INIS)

    Lacotte, Pierre

    2012-01-01

    This work was intended to discover small organic molecules acting as iodide uptake inhibitors in thyroid cells. These compounds can indeed be derivatized into biochemical probes for further characterization of proteins involved in iodide transport mechanisms. On the long term, these inhibitors also appear as attractive drug candidates for treatment of thyroid pathologies or radioprotection against iodine isotopes. A similar strategy was adopted for both of the two inhibitor families. First, we synthesized a chemical library of around 100 analogues; we measured their IC50 against iodide uptake in FRTL-5 cells to get structure-activity relationships. Absolute configuration of stereo-genic centers was also investigated, and a preferential stereochemistry was found to be responsible for activity. From this basis, around twenty 'second-generation' analogues were synthesized by combining fragments contributing to biological activity. Biological evaluation indicated that nine were very potent inhibitors, with IC50 ≤ 6 nM and satisfying physicochemical properties required for drug candidates. Finally, one photoactivatable biotinylated probe was developed in each family and used for photoaffinity labeling. Several specifically labeled proteins are still under identification and constitute new potential therapeutic targets. (author)

  10. Could Sirtuin Activities Modify ALS Onset and Progression?

    Science.gov (United States)

    Tang, Bor Luen

    2017-10-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a complex etiology. Sirtuins have been implicated as disease-modifying factors in several neurological disorders, and in the past decade, attempts have been made to check if manipulating Sirtuin activities and levels could confer benefit in terms of neuroprotection and survival in ALS models. The efforts have largely focused on mutant SOD1, and while limited in scope, the results were largely positive. Here, the body of work linking Sirtuins with ALS is reviewed, with discussions on how Sirtuins and their activities may impact on the major etiological mechanisms of ALS. Moving forward, it is important that the potentially beneficial effect of Sirtuins in ALS disease onset and progression are assessed in ALS models with TDP-43, FUS, and C9orf72 mutations.

  11. Synthesis and Biological Evaluation of Resveratrol Derivatives as Melanogenesis Inhibitors

    Directory of Open Access Journals (Sweden)

    Qing Liu

    2015-09-01

    Full Text Available Resveratrol (1, a naturally occurring stilbene compound, has been suggested as a potential whitening agent with strong inhibitory activity on melanin synthesis. However, the use of resveratrol in cosmetics has been limited due to its chemical instability and poor bioavailability. Therefore, resveratrol derivatives were prepared to improve bioavailability and anti-melanogenesis activity. Nine resveratrol derivatives including five alkyl ether derivatives with C2H5, C4H9, C5H11, C6H13, and C8H17 (2a–2e and four ester derivatives with CH3, CH=C(CH32, CH(C2H5C4H9, C7H15 (3a–3d were newly synthesized and their effect on melanin synthesis were assessed. All the synthetic derivatives efficiently reduced the melanin content in α-MSH stimulated B16F10 melanoma cells. Further investigation showed that the inhibitory effect of 2a on melanin synthesis was achieved not by the inhibition of tyrosinase activity but by the inhibition of melanogenic enzyme expressions such as tyrosinase and tyrosinase-related protein (TRP-1. Our synthetic resveratrol derivatives have more lipophilic properties than resveratrol by the addition of alkyl or acyl chains to free hydroxyl moiety of resveratrol; thus, they are expected to show better bioavailability in skin application. Therefore, we suggest that our synthetic resveratrol derivatives might be promising candidates for better practical application to skin-whitening cosmetics.

  12. Design, Synthesis, and Biological Activity of 1,2,3-Triazolobenzodiazepine BET Bromodomain Inhibitors.

    Science.gov (United States)

    Sharp, Phillip P; Garnier, Jean-Marc; Hatfaludi, Tamas; Xu, Zhen; Segal, David; Jarman, Kate E; Jousset, Hélène; Garnham, Alexandra; Feutrill, John T; Cuzzupe, Anthony; Hall, Peter; Taylor, Scott; Walkley, Carl R; Tyler, Dean; Dawson, Mark A; Czabotar, Peter; Wilks, Andrew F; Glaser, Stefan; Huang, David C S; Burns, Christopher J

    2017-12-14

    A number of diazepines are known to inhibit bromo- and extra-terminal domain (BET) proteins. Their BET inhibitory activity derives from the fusion of an acetyl-lysine mimetic heterocycle onto the diazepine framework. Herein we describe a straightforward, modular synthesis of novel 1,2,3-triazolobenzodiazepines and show that the 1,2,3-triazole acts as an effective acetyl-lysine mimetic heterocycle. Structure-based optimization of this series of compounds led to the development of potent BET bromodomain inhibitors with excellent activity against leukemic cells, concomitant with a reduction in c- MYC expression. These novel benzodiazepines therefore represent a promising class of therapeutic BET inhibitors.

  13. The synthesis of a tritium, carbon-14, and stable isotope-labeled cathepsin C inhibitors.

    Science.gov (United States)

    Allen, Paul; Bragg, Ryan A; Caffrey, Moya; Ericsson, Cecilia; Hickey, Michael J; Kingston, Lee P; Elmore, Charles S

    2017-02-01

    As part of a medicinal chemistry program aimed at developing a highly potent and selective cathepsin C inhibitor, tritium, carbon-14, and stable isotope-labeled materials were required. The synthesis of tritium-labeled methanesulfonate 5 was achieved via catalytic tritiolysis of a chloro precursor, albeit at a low radiochemical purity of 67%. Tritium-labeled AZD5248 was prepared via a 3-stage synthesis, utilizing amide-directed hydrogen isotope exchange. Carbon-14 and stable isotope-labeled AZD5248 were successfully prepared through modifications of the medicinal chemistry synthetic route, enabling the use of available labeled intermediates. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Safe taste memory consolidation is disrupted by a protein synthesis inhibitor in the nucleus accumbens shell.

    Science.gov (United States)

    Pedroza-Llinás, R; Ramírez-Lugo, L; Guzmán-Ramos, K; Zavala-Vega, S; Bermúdez-Rattoni, F

    2009-07-01

    Consolidation is the process by which a new memory is stabilized over time, and is dependent on de novo protein synthesis. A useful model for studying memory formation is gustatory memory, a type of memory in which a novel taste may become either safe by not being followed by negative consequences (attenuation of neophobia, AN), or aversive by being followed by post-digestive malaise (conditioned taste aversion, CTA). Here we evaluated the effects of the administration of a protein synthesis inhibitor in the nucleus accumbens (NAc) shell for either safe or aversive taste memory trace consolidation. To test the effects on CTA and AN of protein synthesis inhibition, anisomycin (100microg/microl) was bilaterally infused into the NAc shell of Wistar rats' brains. We found that post-trial protein synthesis blockade impaired the long-term safe taste memory. However, protein synthesis inhibition failed to disrupt the long-term memory of CTA. In addition, we infused anisomycin in the NAc shell after the pre-exposure to saccharin in a latent inhibition of aversive taste. We found that the protein synthesis inhibition impaired the consolidation of safe taste memory, allowing the aversive taste memory to form and consolidate. Our results suggest that protein synthesis is required in the NAc shell for consolidation of safe but not aversive taste memories, supporting the notion that consolidation of taste memory is processed in several brain regions in parallel, and implying that inhibitory interactions between both taste memory traces do occur.

  15. Sirtuins as regulators of the yeast metabolic network

    Directory of Open Access Journals (Sweden)

    Markus eRalser

    2012-03-01

    Full Text Available There is growing evidence that the metabolic network is an integral regulator of cellularphysiology. Dynamic changes in metabolite concentrations, metabolic flux, or networktopology act as reporters of biological or environmental signals, and are required for the cellto trigger an appropriate biological reaction. Changes in the metabolic network are recognizedby specific sensory macromolecules and translated into a transcriptional or translationalresponse. The protein family of sirtuins, discovered more than 30 years ago as regulators ofsilent chromatin, seems to fulfill the role of a metabolic sensor during aging and conditions ofcaloric restriction. NAD+/NADH interconverting metabolic enzymes glyceraldehyde-3-phosphate dehydrogenase and alcohol dehydrogenase, as well as enzymes involved inNAD(H, synthesis provide or deprive NAD+ in close proximity to Sir2. This influence sirtuinactivity, and facilitates a dynamic response of the metabolic network to changes inmetabolism with effects on physiology and aging. The molecular network downstream Sir2,however, is complex. In just two orders, Sir2’s metabolism-related interactions span half ofthe yeast proteome, and are connected with virtually every physiological process. Thus,although it is fundamental to analyze single molecular mechanisms, it is at the same timecrucial to consider this genome-scale complexity when correlating single molecular eventswith phenotypes such as aging, cell growth, or stress resistance.

  16. Design and Synthesis of New Peptidomimetics as Potential Inhibitors of MurE.

    Science.gov (United States)

    Zivec, Matej; Turk, Samo; Blanot, Didier; Gobec, Stanislav

    2011-03-01

    With the continuing emergence and spread of multidrug-resistant bacteria, there is an urgent need for the development of new antimicrobial agents. One possible source of new antibacterial targets is the biosynthesis of the bacterial cell-wall peptidoglycan. The assembly of the peptide stem is carried out by four essential enzymes, known as the Mur ligases (MurC, D, E and F). We have designed and synthesised a focused library of compounds as potential inhibitors of UDP-N-acetylmuramoyl-L-alanyl-D-glutamate:L-lysine ligase (MurE) from Staphylococcus aureus. This was achieved using two approaches: (i) synthesis of transition-state analogues based on the methyleneamino core; and (ii) synthesis of MurE reaction product analogues. Two methyleneamino-based compounds are identified as initial hits for inhibitors of MurE.

  17. JTP-103237, a monoacylglycerol acyltransferase inhibitor, prevents fatty liver and suppresses both triglyceride synthesis and de novo lipogenesis

    Directory of Open Access Journals (Sweden)

    Chihiro Okuma

    2015-07-01

    Conclusion: In the present study, JTP-103237 prevented carbohydrate-induced fatty liver and suppressed both TG synthesis and de novo lipogenesis, suggesting MGAT inhibitor may prevent carbohydrate-induced metabolic disorders, including NAFLD, obesity and diabetes.

  18. Inhibitors

    Science.gov (United States)

    ... JM, and the Hemophilia Inhibitor Research Study Investigators. Validation of Nijmegen-Bethesda assay modifications to allow inhibitor ... webinars on blood disorders Language: English (US) Español (Spanish) File Formats Help: How do I view different ...

  19. Synthesis and Characterization of Novel Acyl-Glycine Inhibitors of GlyT2.

    Science.gov (United States)

    Mostyn, Shannon N; Carland, Jane E; Shimmon, Susan; Ryan, Renae M; Rawling, Tristan; Vandenberg, Robert J

    2017-09-20

    It has been demonstrated previously that the endogenous compound N-arachidonyl-glycine inhibits the glycine transporter GlyT2, stimulates glycinergic neurotransmission, and provides analgesia in animal models of neuropathic and inflammatory pain. However, it is a relatively weak inhibitor with an IC 50 of 9 μM and is subject to oxidation via cyclooxygenase, limiting its therapeutic value. In this paper we describe the synthesis and testing of a novel series of monounsaturated C18 and C16 acyl-glycine molecules as inhibitors of the glycine transporter GlyT2. We demonstrate that they are up to 28 fold more potent that N-arachidonyl-glycine with no activity at the closely related GlyT1 transporter at concentrations up to 30 μM. This novel class of compounds show considerable promise as a first generation of GlyT2 transport inhibitors.

  20. Design and synthesis of 4-heteroaryl 1,2,3,4-tetrahydroisoquinolines as triple reuptake inhibitors.

    Science.gov (United States)

    Liu, Shuang; Zha, Congxiang; Nacro, Kassoum; Hu, Min; Cui, Wenge; Yang, Yuh-Lin; Bhatt, Ulhas; Sambandam, Aruna; Isherwood, Matthew; Yet, Larry; Herr, Michael T; Ebeltoft, Sarah; Hassler, Carla; Fleming, Linda; Pechulis, Anthony D; Payen-Fornicola, Anne; Holman, Nicholas; Milanowski, Dennis; Cotterill, Ian; Mozhaev, Vadim; Khmelnitsky, Yuri; Guzzo, Peter R; Sargent, Bruce J; Molino, Bruce F; Olson, Richard; King, Dalton; Lelas, Snjezana; Li, Yu-Wen; Johnson, Kim; Molski, Thaddeus; Orie, Anitra; Ng, Alicia; Haskell, Roy; Clarke, Wendy; Bertekap, Robert; O'Connell, Jonathan; Lodge, Nicholas; Sinz, Michael; Adams, Stephen; Zaczek, Robert; Macor, John E

    2014-07-10

    A series of 4-bicyclic heteroaryl 1,2,3,4-tetrahydroisoquinoline inhibitors of the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT) was discovered. The synthesis and structure-activity relationship (SAR) of these triple reuptake inhibitors (TRIs) will be discussed. Compound 10i (AMR-2), a very potent inhibitor of SERT, NET, and DAT, showed efficacy in the rat forced-swim and mouse tail suspension models with minimum effective doses of 0.3 and 1 mg/kg (po), respectively. At efficacious doses in these assays, 10i exhibited substantial occupancy levels at the three transporters in both rat and mouse brain. The study of the metabolism of 10i revealed the formation of a significant active metabolite, compound 13.

  1. Effects of inhibitors of DNA synthesis and protein synthesis on the rate of DNA synthesis after exposure of mammalian cells to ultraviolet light

    International Nuclear Information System (INIS)

    Griffiths, T.D.; Dahle, D.B.; Meechan, P.J.; Carpenter, J.G.

    1981-01-01

    Chinese hamster V-79 cells were treated with metabolic inhibitors of DNA or protein synthesis for various intervals of time after exposure of 3.0 or 5.0 J m -2 . After removal of the metabolic block(s) the rate of DNA synthesis was followed by measuring the incorporation of [ 14 C]thymidine into acid-insoluble material. A 2.5 or 5.0h incubation with cycloheximide or hydroxyurea was effective in delaying the onset of the recovery in the rate of DNA synthesis that normally becomes evident several hours after exposure to ultraviolet light. By using concentrations of cycloheximide or hydroxyurea that inhibit DNA synthesis by a similar amount (70%), but protein synthesis by vastly different amounts (95% for cycloheximide; 0% for hydroxyurea), it was apparent that the delay in recovery caused by the treatment of the cells with cycloheximide could be accounted for entirely by its inhibitory effect on DNA synthesis. This suggests that the recovery in DNA synthetic rates following exposure of V-79 cells to ultraviolet light does not appear to require de novo protein synthesis, and therefore does not appear to require the involvement of an inducible DNA repair process. (Auth.)

  2. Sirtuins of parasitic protozoa: In search of function(s)

    OpenAIRE

    Religa, Agnieszka A.; Waters, Andrew P.

    2012-01-01

    The SIR2 family of NAD+-dependent protein deacetylases, collectively called sirtuins, has been of central interest due to their proposed roles in life-span regulation and ageing. Sirtuins are one group of environment sensors of a cell interpreting external information and orchestrating internal responses at the sub-cellular level, through participation in gene regulation mechanisms. Remarkably conserved across all kingdoms of life SIR2 proteins in several protozoan parasites appear to have bo...

  3. Inhibitor of DNA synthesis is present in normal chicken serum

    International Nuclear Information System (INIS)

    Franklin, R.A.; Davila, D.R.; Westly, H.J.; Kelley, K.W.

    1986-01-01

    The authors have found that heat-inactivated serum (57 0 C for 1 hour) from normal chickens reduces the proliferation of mitogen-stimulated chicken and murine splenocytes as well as some transformed mammalian lymphoblastoid cell lines. Greater than a 50% reduction in 3 H-thymidine incorporation was observed when concanavalin A (Con A)-activated chicken splenocytes that were cultured in the presence of 10% autologous or heterologous serum were compared to mitogen-stimulated cells cultured in the absence of serum. Normal chicken serum (10%) also caused greater than 95% suppression of 3 H-thymidine incorporation by bovine (EBL-1 and BL-3) and gibbon ape (MLA 144) transformed lymphoblastoid cell lines. The only cell line tested that was not inhibited by chicken serum was an IL-2-dependent, murine cell line. Chicken serum also inhibited both 3 H-thymidine incorporation and IL-2 synthesis by Con A-activated murine splenocytes. Suppression was caused by actions other than cytotoxicity because viability of chicken splenocytes was unaffected by increasing levels of chicken serum. Furthermore, dialyzed serum retained its activity, which suggested that thymidine in the serum was not inhibiting uptake of radiolabeled thymidine. Suppressive activity was not due to adrenal glucocorticoids circulating in plasma because neither physiologic nor pharmacologic doses of corticosterone had inhibitory effects on mitogen-stimulated chicken splenocytes. These data demonstrate that an endogenous factor that is found in normal chicken serum inhibits proliferation of T-cells from chickens and mice as well as some transformed mammalian lymphoblastoid cell lines

  4. The TosMIC approach to 3-(oxazol-5-yl) indoles: application to the synthesis of indole-based IMPDH inhibitors.

    Science.gov (United States)

    Dhar, T G Murali; Shen, Zhongqi; Fleener, Catherine A; Rouleau, Katherine A; Barrish, Joel C; Hollenbaugh, Diane L; Iwanowicz, Edwin J

    2002-11-18

    A modified approach to the synthesis of 3-(oxazolyl-5-yl) indoles is reported. This method was applied to the synthesis of series of novel indole based inhibitors of inosine monophosphate dehydrogenase (IMPDH). The synthesis and the structure-activity relationships (SARs), derived from in vitro studies, for this new series of inhibitors is given.

  5. Comparative Modeling and Benchmarking Data Sets for Human Histone Deacetylases and Sirtuin Families

    Science.gov (United States)

    Xia, Jie; Tilahun, Ermias Lemma; Kebede, Eyob Hailu; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

    2015-01-01

    Histone Deacetylases (HDACs) are an important class of drug targets for the treatment of cancers, neurodegenerative diseases and other types of diseases. Virtual screening (VS) has become fairly effective approaches for drug discovery of novel and highly selective Histone Deacetylases Inhibitors (HDACIs). To facilitate the process, we constructed the Maximal Unbiased Benchmarking Data Sets for HDACs (MUBD-HDACs) using our recently published methods that were originally developed for building unbiased benchmarking sets for ligand-based virtual screening (LBVS). The MUBD-HDACs covers all 4 Classes including Class III (Sirtuins family) and 14 HDACs isoforms, composed of 631 inhibitors and 24,609 unbiased decoys. Its ligand sets have been validated extensively as chemically diverse, while the decoy sets were shown to be property-matching with ligands and maximal unbiased in terms of “artificial enrichment” and “analogue bias”. We also conducted comparative studies with DUD-E and DEKOIS 2.0 sets against HDAC2 and HDAC8 targets, and demonstrate that our MUBD-HDACs is unique in that it can be applied unbiasedly to both LBVS and SBVS approaches. In addition, we defined a novel metric, i.e. NLBScore, to detect the “2D bias” and “LBVS favorable” effect within the benchmarking sets. In summary, MUBD-HDACs is the only comprehensive and maximal-unbiased benchmark data sets for HDACs (including Sirtuins) that is available so far. MUBD-HDACs is freely available at http://www.xswlab.org/. PMID:25633490

  6. Comparative modeling and benchmarking data sets for human histone deacetylases and sirtuin families.

    Science.gov (United States)

    Xia, Jie; Tilahun, Ermias Lemma; Kebede, Eyob Hailu; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

    2015-02-23

    Histone deacetylases (HDACs) are an important class of drug targets for the treatment of cancers, neurodegenerative diseases, and other types of diseases. Virtual screening (VS) has become fairly effective approaches for drug discovery of novel and highly selective histone deacetylase inhibitors (HDACIs). To facilitate the process, we constructed maximal unbiased benchmarking data sets for HDACs (MUBD-HDACs) using our recently published methods that were originally developed for building unbiased benchmarking sets for ligand-based virtual screening (LBVS). The MUBD-HDACs cover all four classes including Class III (Sirtuins family) and 14 HDAC isoforms, composed of 631 inhibitors and 24609 unbiased decoys. Its ligand sets have been validated extensively as chemically diverse, while the decoy sets were shown to be property-matching with ligands and maximal unbiased in terms of "artificial enrichment" and "analogue bias". We also conducted comparative studies with DUD-E and DEKOIS 2.0 sets against HDAC2 and HDAC8 targets and demonstrate that our MUBD-HDACs are unique in that they can be applied unbiasedly to both LBVS and SBVS approaches. In addition, we defined a novel metric, i.e. NLBScore, to detect the "2D bias" and "LBVS favorable" effect within the benchmarking sets. In summary, MUBD-HDACs are the only comprehensive and maximal-unbiased benchmark data sets for HDACs (including Sirtuins) that are available so far. MUBD-HDACs are freely available at http://www.xswlab.org/ .

  7. Synthesis, cytotoxicity and molecular modelling studies of new phenylcinnamide derivatives as potent inhibitors of cholinesterases.

    Science.gov (United States)

    Saeed, Aamer; Mahesar, Parvez Ali; Zaib, Sumera; Khan, Muhammad Siraj; Matin, Abdul; Shahid, Mohammad; Iqbal, Jamshed

    2014-05-06

    The present study reports the synthesis of cinnamide derivatives and their biological activity as inhibitors of both cholinesterases and anticancer agents. Controlled inhibition of brain acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) may slow neurodegeneration in Alzheimer's diseases (AD). The anticholinesterase activity of phenylcinnamide derivatives was determined against Electric Eel acetylcholinesterase (EeAChE) and horse serum butyrylcholinesterase (hBChE) and some of the compounds appeared as moderately potent inhibitors of EeAChE and hBChE. The compound 3-(2-(Benzyloxy)phenyl)-N-(3,4,5-trimethoxyphenyl)acrylamide (3i) showed maximum activity against EeAChE with an IC50 0.29 ± 0.21 μM whereas 3-(2-chloro-6-nitrophenyl)-N-(3,4,5-trimethoxyphenyl)acrylamide (3k) was proved to be the most potent inhibitor of hBChE having IC50 1.18 ± 1.31 μM. To better understand the enzyme-inhibitor interaction of the most active compounds toward cholinesterases, molecular modelling studies were carried out on high-resolution crystallographic structures. The anticancer effects of synthesized compounds were also evaluated against cancer cell line (lung carcinoma). The compounds may be useful leads for the design of a new class of anticancer drugs for the treatment of cancer and cholinesterase inhibitors for Alzheimer's disease (AD). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. Structure-Based Design and Synthesis of Potent and Selective Matrix Metalloproteinase 13 Inhibitors.

    Science.gov (United States)

    Choi, Jun Yong; Fuerst, Rita; Knapinska, Anna M; Taylor, Alexander B; Smith, Lyndsay; Cao, Xiaohang; Hart, P John; Fields, Gregg B; Roush, William R

    2017-07-13

    We describe the use of comparative structural analysis and structure-guided molecular design to develop potent and selective inhibitors (10d and (S)-17b) of matrix metalloproteinase 13 (MMP-13). We applied a three-step process, starting with a comparative analysis of the X-ray crystallographic structure of compound 5 in complex with MMP-13 with published structures of known MMP-13·inhibitor complexes followed by molecular design and synthesis of potent but nonselective zinc-chelating MMP inhibitors (e.g., 10a and 10b). After demonstrating that the pharmacophores of the chelating inhibitors (S)-10a, (R)-10a, and 10b were binding within the MMP-13 active site, the Zn 2+ chelating unit was replaced with nonchelating polar residues that bridged over the Zn 2+ binding site and reached into a solvent accessible area. After two rounds of structural optimization, these design approaches led to small molecule MMP-13 inhibitors 10d and (S)-17b, which bind within the substrate-binding site of MMP-13 and surround the catalytically active Zn 2+ ion without chelating to the metal. These compounds exhibit at least 500-fold selectivity versus other MMPs.

  9. Metabolic approaches to enhance transdermal drug delivery. 1. Effect of lipid synthesis inhibitors.

    Science.gov (United States)

    Tsai, J C; Guy, R H; Thornfeldt, C R; Gao, W N; Feingold, K R; Elias, P M

    1996-06-01

    The intercellular domains of the stratum corneum, which contain a mixture of cholesterol, free fatty acids, and ceramides, mediate both the epidermal permeability barrier and the transdermal delivery of both lipophilic and hydrophilic molecules. Prior studies have shown that each of the three key lipid classes is required for normal barrier function. For example, selective inhibition of either cholesterol, fatty acid, or ceramide synthesis in the epidermis delays barrier recovery rates after barrier perturbation of hairless mouse skin in vivo. In this study, we investigated the potential of certain inhibitors of lipid synthesis to enhance the transdermal delivery of lidocaine or caffeine as a result of their capacity to perturb barrier homeostasis. After acetone disruption of the barrier, the extent of lidocaine delivery and the degree of altered barrier function paralleled each other. Moreover, the further alteration in barrier function produced by either the fatty acid synthesis inhibitor 5-(tetradecyloxy)-2-furancarboxylic acid (TOFA), the cholesterol synthesis inhibitor fluvastatin (FLU), or cholesterol sulfate (CS) resulted in a further increase in lidocaine absorption. Furthermore, coapplications of TOFA and CS together caused an additive increase in lidocaine uptake. Finally, a comparable increase in drug delivery occurred when the barrier was disrupted initially with DMSO instead of acetone; coapplications of TOFA and FLU together again delayed barrier recovery and increased drug delivery by about 8-fold vs delivery from a standard enhancing vehicle. Whereas these metabolic inhibitors also variably increased the octanol/water partitioning of the drugs studied (perhaps via complexion or pH alterations), physicochemical effects of the inhibitors alone did not alter drug uptake in intact skin; i.e., passive mechanisms alone cannot account for the net increase in drug delivery. Our results show that modulations of epidermal lipid biosynthesis, following

  10. Seeding for sirtuins: microseed matrix seeding to obtain crystals of human Sirt3 and Sirt2 suitable for soaking

    Energy Technology Data Exchange (ETDEWEB)

    Rumpf, Tobias [Albert-Ludwigs-University Freiburg, Albertstrasse 25, 79104 Freiburg, Baden-Württemberg (Germany); Gerhardt, Stefan; Einsle, Oliver, E-mail: einsle@biochemie.uni-freiburg.de [Albert-Ludwigs-University Freiburg, Albertstrasse 21, 79104 Freiburg, Baden-Württemberg (Germany); Jung, Manfred, E-mail: einsle@biochemie.uni-freiburg.de [Albert-Ludwigs-University Freiburg, Albertstrasse 25, 79104 Freiburg, Baden-Württemberg (Germany)

    2015-11-18

    In the present study, microseed matrix seeding was successfully applied to obtain a large number of crystals of the human sirtuin isotypes Sirt2 and Sirt3. These crystals appeared predictably in diverse crystallization conditions, diffracted to a higher resolution than reported in the literature and were subsequently used to study the protein–ligand interactions of two indole inhibitors. Sirtuins constitute a family of NAD{sup +}-dependent enzymes that catalyse the cleavage of various acyl groups from the ∊-amino group of lysines. They regulate a series of cellular processes and their misregulation has been implicated in various diseases, making sirtuins attractive drug targets. To date, only a few sirtuin modulators have been reported that are suitable for cellular research and their development has been hampered by a lack of structural information. In this work, microseed matrix seeding (MMS) was used to obtain crystals of human Sirt3 in its apo form and of human Sirt2 in complex with ADP ribose (ADPR). Crystal formation using MMS was predictable, less error-prone and yielded a higher number of crystals per drop than using conventional crystallization screening methods. The crystals were used to solve the crystal structures of apo Sirt3 and of Sirt2 in complex with ADPR at an improved resolution, as well as the crystal structures of Sirt2 in complex with ADPR and the indoles EX527 and CHIC35. These Sirt2–ADPR–indole complexes unexpectedly contain two indole molecules and provide novel insights into selective Sirt2 inhibition. The MMS approach for Sirt2 and Sirt3 may be used as the basis for structure-based optimization of Sirt2/3 inhibitors in the future.

  11. Direct modulation of T-box riboswitch-controlled transcription by protein synthesis inhibitors.

    Science.gov (United States)

    Stamatopoulou, Vassiliki; Apostolidi, Maria; Li, Shuang; Lamprinou, Katerina; Papakyriakou, Athanasios; Zhang, Jinwei; Stathopoulos, Constantinos

    2017-09-29

    Recently, it was discovered that exposure to mainstream antibiotics activate numerous bacterial riboregulators that control antibiotic resistance genes including metabolite-binding riboswitches and other transcription attenuators. However, the effects of commonly used antibiotics, many of which exhibit RNA-binding properties, on the widespread T-box riboswitches, remain unknown. In Staphylococcus aureus, a species-specific glyS T-box controls the supply of glycine for both ribosomal translation and cell wall synthesis, making it a promising target for next-generation antimicrobials. Here, we report that specific protein synthesis inhibitors could either significantly increase T-box-mediated transcription antitermination, while other compounds could suppress it, both in vitro and in vivo. In-line probing of the full-length T-box combined with molecular modelling and docking analyses suggest that the antibiotics that promote transcription antitermination stabilize the T-box:tRNA complex through binding specific positions on stem I and the Staphylococcal-specific stem Sa. By contrast, the antibiotics that attenuate T-box transcription bind to other positions on stem I and do not interact with stem Sa. Taken together, our results reveal that the transcription of essential genes controlled by T-box riboswitches can be directly modulated by commonly used protein synthesis inhibitors. These findings accentuate the regulatory complexities of bacterial response to antimicrobials that involve multiple riboregulators. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  12. Resveratrol attenuates CoCl2-induced cochlear hair cell damage through upregulation of Sirtuin1 and NF-κB deacetylation.

    Directory of Open Access Journals (Sweden)

    Ping Wang

    Full Text Available The goals of this study were to investigate the effects of hypoxia on cochlear hair cell damage, and to explore the role of sirtuin1 in hypoxia-induced hair cell damage. Cochlear organotypic cultures from postnatal day 4 rats were used in this study. Hypoxia was induced by treating cochlear explants with CoCl2. Cochlear cultures were treated with CoCl2 alone or in combination with the sirtuin1 activator resveratrol and the sirtuin1 inhibitor sirtinol. Hair cell damage was identified by phalloidin staining and imaged using scanning electron microscopy. RT-PCR and Western blot analyses were used to detect the expression of sirtuin1 and acetylated nuclear factor-κB (NF-κB. Low concentrations of CoCl2 (100-200 μM did not cause an obvious change in the number and morphology of hair cells, whereas higher concentrations of CoCl2 (300-400 μM induced swelling of hair cells, accompanied by cell loss. Increased sirtuin1 expression was induced by CoCl2 at 100 to 200 μM, but not at 400 μM. NF-κB acetylation was significantly increased in explants treated with 400 μM CoCl2. Pretreatment with resveratrol prevented CoCl2-induced hair cell loss and acetylation of NF-κB. The protective effect of resveratrol was significantly reduced by sirtinol. CoCl2 induces hair cell damage in organotypic cochleae cultures. Resveratrol attenuates CoCl2-induced cochlear hair cell damage possibly via activation of sirtuin1, which deacetylates NF-κB.

  13. Design, Synthesis and Evaluation of Ribose-modified Anilinopyrimidine Derivatives as EGFR Tyrosine Kinase Inhibitors

    Science.gov (United States)

    Hu, Xiuqin; Wang, Disha; Tong, Yi; Tong, Linjiang; Wang, Xia; Zhu, Lili; Xie, Hua; Li, Shiliang; Yang, You; Xu, Yufang

    2017-11-01

    The synthesis of a series of ribose-modified anilinopyrimidine derivatives was efficiently achieved by utilizing DBU or tBuOLi-promoted coupling of ribosyl alcohols with 2,4,5-trichloropyrimidine as key step. Preliminary biological evaluation of this type of compounds as new EGFR tyrosine kinase inhibitors for combating EGFR L858R/T790M mutant associated with drug resistance in the treatment of non-small cell lung cancer revealed that 3-N-acryloyl-5-O-anilinopyrimidine ribose derivative 1a possessed potent and specific inhibitory activity against EGFR L858R/T790M over WT EGFR. Based upon molecular docking studies of the binding mode between compound 1a and EGFR, the distance between the Michael receptor and the pyrimidine scaffold is considered as an important factor for the inhibitory potency and future design of selective EGFR tyrosine kinase inhibitors against EGFR L858R/T790M mutants.

  14. Design, Synthesis, and Evaluation of Novel Tyrosine-Based DNA Gyrase B Inhibitors.

    Science.gov (United States)

    Cotman, Andrej E; Trampuž, Marko; Brvar, Matjaž; Kikelj, Danijel; Ilaš, Janez; Peterlin-Mašič, Lucija; Montalvão, Sofia; Tammela, Päivi; Frlan, Rok

    2017-08-01

    The discovery and synthesis of new tyrosine-based inhibitors of DNA gyrase B (GyrB), which target its ATPase subunit, is reported. Twenty-four compounds were synthesized and evaluated for activity against DNA gyrase and DNA topoisomerase IV. The antibacterial properties of selected GyrB inhibitors were demonstrated by their activity against Staphylococcus aureus and Enterococcus faecalis in the low micromolar range. The most promising compounds, 8a and 13e, inhibited Escherichia coli and S. aureus GyrB with IC 50 values of 40 and 30 µM. The same compound also inhibited the growth of S. aureus and E. faecalis with minimal inhibitory concentrations (MIC 90 ) of 14 and 28 µg/mL, respectively. © 2017 Deutsche Pharmazeutische Gesellschaft.

  15. Phenotypic Screening Identifies Protein Synthesis Inhibitors as H-Ras-Nanocluster-Increasing Tumor Growth Inducers.

    Science.gov (United States)

    Najumudeen, Arafath K; Posada, Itziar M D; Lectez, Benoit; Zhou, Yong; Landor, Sebastian K-J; Fallarero, Adyary; Vuorela, Pia; Hancock, John; Abankwa, Daniel

    2015-12-15

    Ras isoforms H-, N-, and K-ras are each mutated in specific cancer types at varying frequencies and have different activities in cell fate control. On the plasma membrane, Ras proteins are laterally segregated into isoform-specific nanoscale signaling hubs, termed nanoclusters. As Ras nanoclusters are required for Ras signaling, chemical modulators of nanoclusters represent ideal candidates for the specific modulation of Ras activity in cancer drug development. We therefore conducted a chemical screen with commercial and in-house natural product libraries using a cell-based H-ras-nanoclustering FRET assay. Next to established Ras inhibitors, such as a statin and farnesyl-transferase inhibitor, we surprisingly identified five protein synthesis inhibitors as positive regulators. Using commonly employed cycloheximide as a representative compound, we show that protein synthesis inhibition increased nanoclustering and effector recruitment specifically of active H-ras but not of K-ras. Consistent with these data, cycloheximide treatment activated both Erk and Akt kinases and specifically promoted H-rasG12V-induced, but not K-rasG12V-induced, PC12 cell differentiation. Intriguingly, cycloheximide increased the number of mammospheres, which are enriched for cancer stem cells. Depletion of H-ras in combination with cycloheximide significantly reduced mammosphere formation, suggesting an exquisite synthetic lethality. The potential of cycloheximide to promote tumor cell growth was also reflected in its ability to increase breast cancer cell tumors grown in ovo. These results illustrate the possibility of identifying Ras-isoform-specific modulators using nanocluster-directed screening. They also suggest an unexpected feedback from protein synthesis inhibition to Ras signaling, which might present a vulnerability in certain tumor cell types.

  16. Synthesis and Biological Evaluation of Glycosidase Inhibitors: gem-Difluoromethylenated Nojirimycin Analogues

    DEFF Research Database (Denmark)

    Bols, Mikael; Wang, Ruo-Wen; Qiu, Xiao-Long

    2006-01-01

    In our ongoing program aimed at the design, synthesis, and biological evaluation of novel gem-difluoromethylenated glycosidase inhibitors, gem-4,4-difluoromethylenated iminosugars (5-9) were synthesized. The biological evaluation of these synthetic iminosugars showed that the gem....... It is proposed that the unprotonated iminosugar is the species preferably bound by beta-glucosidase, due to the lower pK(a) value of iminosugar 6 than of 1 or 36, leaving iminosugars 1 and 36 mostly protonated at pH 5.0, while iminosugar 6 is not. Iminosugar 6 also displayed good and selective inhibition of beta...

  17. Purification and properties of a mitochondrial lipoprotein inhibitor of sterol synthesis

    International Nuclear Information System (INIS)

    Madhosingh, C.; Migicovsky, B.B.; Starratt, A.N.

    1976-01-01

    A lipoprotein inhibitor of hydroxymethylglutaryl CoA reductase (EC 1.1.1.34) and of cholesterol synthesis by rat liver homogenates, was isolated from the mitochondria of starved rats' livers. The isolated lipoprotein complex contained a low molecular weight protein and fatty acids. The fatty acids identified were arachidonic, linoleic, oleic, stearic and palmitic. The saturated fatty acids and oleic acid did not inhibit. Inhibition of the enzyme was to a large extent related to the degree of fatty acid unsaturation. (auth.)

  18. Resveratrol relieves Angiostrongylus cantonensis - Induced meningoencephalitis by activating sirtuin-1.

    Science.gov (United States)

    Chen, An-Chih; Shyu, Ling-Yuh; Hsin, Yue-Loong; Chen, Ke-Min; Lai, Shih-Chan

    2017-09-01

    Resveratrol, a natural herbal compound found in high levels in grapes and red wine, is frequently used as activator of sirtuin-1. This study investigated the potential function of sirtuin-1 in regulating angiostrongyliasis meningoencephalitis in resveratrol-treated mice. Mice were subjected to meningoencephalitis to study the protective effect of resveratrol against meningoencephalitis and investigate the effects of sirtuin-1 activation on brain. Results demonstrated that sirtuin-1 level decreased in mice with meningoencephalitis and significantly increased in resveratrol-treated mice. Moreover, resveratrol treatment significantly reduced eosinophil counts, p65, Interferon-γ, interleukin (IL)-5, IL-33, and tumor necrosis factor-α levels, matrix metalloproteinase-9 activity, claudin-5 degradation, and blood-brain barrier permeability. By contrast, the anti-inflammatory factor IL-10 was significantly increased in resveratrol-treated mice. Resveratrol treatment was partially beneficial in controlling the pathological processes of angiostrongyliasis meningoencephalitis. The results demonstrate the neuroprotective and anti-inflammatory effects of resveratrol against Angiostrongylus cantonensis-induced eosinophilic meningoencephalitis in mice. Treatment with sirtuin-1 agonist was given within a therapeutic window after A. cantonensis infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The effect of Ramadan fasting on sirtuin and visfatin levels.

    Science.gov (United States)

    Engin-Ustun, Yaprak; Caglayan, Emel Kiyak; Kara, Mustafa; Gocmen, Ayse Yesim; Polat, M Fevzi; Aktulay, Ayla

    2016-03-01

    Our aim was to determine how Ramadan fasting effects serum Human NAD-dependent deacetylase sirtuin 1 (SIRT1/SIR2L1) and visfatin levels during pregnancy. Thirty-six patients were included in this case-control study. The patient group consisted of 18 pregnant women who were Ramadan fasting. Another healthy 18 pregnant women with matching pregnancy weeks and ages formed the control group. Blood samples were obtained from the patients for biochemical analyses and serum adipokine level measurements. The mean sirtuin and visfatin levels in fasting pregnant women were 2.87 ± 0.95 and 60.18 ± 19.49 ng/mL, respectively, while the mean serum sirtuin and visfatin levels in the control group was determined to be 4.28 ± 1.45 and 23.26 ± 6.18 ng/mL, respectively. A statistically significant difference was determined between the groups ( p = 0.002, p = 0.0001). A correlation analysis provided a negative correlation between number of fasting days and sirtuin levels ( r = 0.45, p = 0.005) and a positive correlation with visfatin levels ( r = 0.73, p = 0.0001). As a result, while the serum sirtuin 1 level of pregnant women decreased due to fasting in Ramadan, we determined that their visfatin levels increased and this increase was in correlation with the days of fasting.

  20. Concurrent acetylation of FoxO1/3a and p53 due to sirtuins inhibition elicit Bim/PUMA mediated mitochondrial dysfunction and apoptosis in berberine-treated HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Shatrunajay [Herbal Research Section, CSIR — Indian Institute of Toxicology Research, Post Box No. 80, Mahatma Gandhi Marg, Lucknow‐226001 (India); Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), Hamdard Nagar, New Delhi ‐110062 (India); Sharma, Ankita [Herbal Research Section, CSIR — Indian Institute of Toxicology Research, Post Box No. 80, Mahatma Gandhi Marg, Lucknow‐226001 (India); Pandey, Vivek Kumar [Herbal Research Section, CSIR — Indian Institute of Toxicology Research, Post Box No. 80, Mahatma Gandhi Marg, Lucknow‐226001 (India); Academy of Scientific and Innovative Research (India); Raisuddin, Sheikh [Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), Hamdard Nagar, New Delhi ‐110062 (India); Kakkar, Poonam, E-mail: kakkarp59@gmail.com [Herbal Research Section, CSIR — Indian Institute of Toxicology Research, Post Box No. 80, Mahatma Gandhi Marg, Lucknow‐226001 (India); Academy of Scientific and Innovative Research (India)

    2016-01-15

    Post-translational modifications i.e. phosphorylation and acetylation are pivotal requirements for proper functioning of eukaryotic proteins. The current study aimed to decode the impact of acetylation/deacetylation of non-histone targets i.e. FoxO1/3a and p53 of sirtuins (NAD{sup +} dependent enzymes with lysine deacetylase activity) in berberine treated human hepatoma cells. Berberine (100 μM) inhibited sirtuins significantly (P < 0.05) at transcriptional level as well as at translational level. Combination of nicotinamide (sirtuin inhibitor) with berberine potentiated sirtuins inhibition and increased the expression of FoxO1/3a and phosphorylation of p53 tumor suppressor protein. As sirtuins deacetylate non-histone targets including FoxO1/3a and p53, berberine increased the acetylation load of FoxO1/3a and p53 proteins. Acetylated FoxO and p53 proteins transcriptionally activate BH3-only proteins Bim and PUMA (3.89 and 3.87 fold respectively, P<0.001), which are known as direct activator of pro-apoptotic Bcl-2 family protein Bax that culminated into mitochondria mediated activation of apoptotic cascade. Bim/PUMA knock-down showed no changes in sirtuins' expression while cytotoxicity induced by berberine and nicotinamide was curtailed up to 28.3% (P < 0.001) and it restored pro/anti apoptotic protein ratio in HepG2 cells. Sirtuins inhibition was accompanied by decline in NAD{sup +}/NADH ratio, ATP generation, enhanced ROS production and decreased mitochondrial membrane potential. TEM analysis confirmed mitochondrial deterioration and cell damage. SRT-1720 (1–10 μM), a SIRT-1 activator, when pre-treated with berberine (25 μM), reversed sirtuins expression comparable to control and significantly restored the cell viability (P < 0.05). Thus, our findings suggest that berberine mediated sirtuins inhibition resulting into FoxO1/3a and p53 acetylation followed by BH3-only protein Bim/PUMA activation may in part be responsible for mitochondria

  1. Effects of DNA polymerase inhibitors on replicative and repair DNA synthesis in ultraviolet-irradiated HeLa cells

    International Nuclear Information System (INIS)

    Morita, T.; Nakamura, H.; Tsutsui, Y.; Nishiyama, Y.; Yoshida, S.

    1982-01-01

    Aphidicolin specifically inhibits eukaryotic DNA polymerase α, while 2',3'-dideoxythymidine 5'-triphosphate (d 2 TTP) inhibits DNA polymerase ν and ν but not α. 1-ν-D-Arabinofuranosylcytosine 5'-triphosphate (araCTP) inhibits both DNA polymerase α and ν although to a different extent. Here we measured the effects of these inhibitors on repair DNA synthesis of U.V.-irradiated HeLa cells by two different methods. Firstly, aphidicolin, 1-ν-D-arabinofuranosylcytosine (araC, a precursor of araCTP) and 2',3'-dideoxythimidine (d 2 Thd, a precursor of d 2 TTP) were added directly to the culture medium. In this case, aphidicolin and araC strongly inhibited replicative DNA synthesis of HeLa cells, and they also inhibited repair synthesis after U.V.-irradiation but to a much lesser extent. In contrast, high concentrations of d 2 Thd inhibited repair DNA synthesis to a higher extent than replicative DNA synthesis. Secondly, the active form of inhibitor, d 2 TTP, was microinjected directly into cytoplasm or nuclei or U.V.-irradiated HeLa cells. Microinjection of d 2 TTP effectively inhibited repair synthesis. The microinjection of d 2 TTP, into either cytoplasm or nucleus, strongly inhibited replicative synthesis. These results might indicate that multiple DNA polymerases are involved in repair synthesis as well as in replicative synthesis

  2. Sirtuins of parasitic protozoa: In search of function(s)

    Science.gov (United States)

    Religa, Agnieszka A.; Waters, Andrew P.

    2012-01-01

    The SIR2 family of NAD+-dependent protein deacetylases, collectively called sirtuins, has been of central interest due to their proposed roles in life-span regulation and ageing. Sirtuins are one group of environment sensors of a cell interpreting external information and orchestrating internal responses at the sub-cellular level, through participation in gene regulation mechanisms. Remarkably conserved across all kingdoms of life SIR2 proteins in several protozoan parasites appear to have both conserved and intriguing unique functions. This review summarises our current knowledge of the members of the sirtuin families in Apicomplexa, including Plasmodium, and other protozoan parasites such as Trypanosoma and Leishmania. The wide diversity of processes regulated by SIR2 proteins makes them targets worthy of exploitation in anti-parasitic therapies. PMID:22906508

  3. Sirtuins, Cell Senescence, and Vascular Aging.

    Science.gov (United States)

    Kida, Yujiro; Goligorsky, Michael S

    2016-05-01

    The sirtuins (SIRTs) constitute a class of proteins with nicotinamide adenine dinucleotide-dependent deacetylase or adenosine diphosphate-ribosyltransferase activity. Seven SIRT family members have been identified in mammals, from SIRT1, the best studied for its role in vascular aging, to SIRT7. SIRT1 and SIRT2 are localized in the nucleus and cytoplasm. SIRT3, SIRT4, and SIRT5 are mitochondrial, and SIRT6 and SIRT7 are nuclear. Extensive studies have clearly revealed that SIRT proteins regulate diverse cell functions and responses to stressors. Vascular aging involves the aging process (senescence) of endothelial and vascular smooth muscle cells. Two types of cell senescence have been identified: (1) replicative senescence with telomere attrition; and (2) stress-induced premature senescence without telomere involvement. Both types of senescence induce vascular cell growth arrest and loss of vascular homeostasis, and contribute to the initiation and progression of cardiovascular diseases. Previous mechanistic studies have revealed in detail that SIRT1, SIRT3, and SIRT6 show protective functions against vascular aging, and definite vascular function of other SIRTs is under investigation. Thus, direct SIRT modulation and nicotinamide adenine dinucleotide stimulation of SIRT are promising candidates for cardiovascular disease therapy. A small number of pilot studies have been conducted to assess SIRT modulation in humans. These clinical studies have not yet provided convincing evidence that SIRT proteins alleviate morbidity and mortality in patients with cardiovascular diseases. The outcomes of multiple ongoing clinical trials are awaited to define the efficacy of SIRT modulators and SIRT activators in cardiovascular diseases, along with the potential adverse effects of chronic SIRT modulation. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  4. Subtype-specific suppression of Shiga toxin 2 released from Escherichia coli upon exposure to protein synthesis inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Malene Gantzhorn; Hansen, Claus; Riise, Erik

    2008-01-01

    Shiga toxins (Stx) are important virulence factors in the pathogenesis of severe disease including hemolytic-uremic syndrome, caused by Stx-producing Escherichia coli (STEC). STEC strains increase the release of Stx in vitro following the addition of fluoroquinolones, whereas protein synthesis...... inhibitors previously have been reported to suppress the release of Stx. The amount of Stx released from wild-type STEC strains incubated with protein synthesis inhibitors was examined by a Vero cell cytotoxicity assay. The amounts released were compared to the Stx type (Stx1 or Stx2) and additionally...... to the individual subtypes and toxin variants of Stx2. In general, Stx2 release was suppressed significantly upon exposure to protein synthesis inhibitors at MICs, which was not observed in the case of Stx1. Also, the average amount of different Stx2 toxin variants released was suppressed to various levels ranging...

  5. Sirtuin 6 protects the heart from hypoxic damage

    International Nuclear Information System (INIS)

    Maksin-Matveev, Anna; Kanfi, Yariv; Hochhauser, Edith; Isak, Ahuva; Cohen, Haim Y.; Shainberg, Asher

    2015-01-01

    Sirtuin 6 (SIRT6) is a protein associated with prolonged life expectancy. We investigated whether life extension is associated with cardioprotection against hypoxia. The proposed study is to develop approaches to reduce hypoxic damage through the use of the sirtuin pathway and to elucidate the mechanism involved. For that purpose we subjected cardiomyocytes from transgenic mice (TG) with over-expression of SIRT6, to hypoxic stress in cell cultures. We hypothesized that cardiomyocytes from transgenic mice subjected to prolonged hypoxia may release survival factors or fewer damage markers to protect them from hypoxic stress compared with wild type (WT) mice. Lactate dehydrogenase (LDH) and creatine kinase (CK) released to the medium and propidium iodide (PI) binding, were markedly decreased following hypoxia in TG cardiomyocytes. The protective mechanism of SIRT6 over-expression includes the activation of pAMPKα pathway, the increased protein level of B-cell lymphoma 2 (Bcl2), the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), the decrease of reactive oxygen species (ROS) and the reduction in the protein level of phospho-protein kinase B (pAkt) during hypoxia. Together, all these processes impede the necrosis/apoptosis pathways leading to the improved survival of cardiomyocytes following hypoxia, which might explain life extension. - Highlights: • Sirtuin 6 is a protein associated with prolonged life expectancy. • Over-expression of sirtuin 6 protects cardiocytes from hypoxia and oxidative stress. • Over-expression of sirtuin 6 activates the pAMPKα pathway and the Bcl2 expression. • Over-expression of sirtuin 6 decreases ROS formation and pAkt level during hypoxia. • These pathways protect cardiocytes from hypoxia and might explain lifespan extension

  6. Sirtuin 6 protects the heart from hypoxic damage

    Energy Technology Data Exchange (ETDEWEB)

    Maksin-Matveev, Anna; Kanfi, Yariv [The Mina and Everard Goodman, Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900 (Israel); Hochhauser, Edith [The Laboratory of the Department of Cardiothoracic Surgery, Felsenstein Medical Research Center, Rabin Medical Center, Petach Tikva (Israel); Isak, Ahuva; Cohen, Haim Y. [The Mina and Everard Goodman, Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900 (Israel); Shainberg, Asher, E-mail: asher.shainberg@gmail.com [The Mina and Everard Goodman, Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900 (Israel)

    2015-01-01

    Sirtuin 6 (SIRT6) is a protein associated with prolonged life expectancy. We investigated whether life extension is associated with cardioprotection against hypoxia. The proposed study is to develop approaches to reduce hypoxic damage through the use of the sirtuin pathway and to elucidate the mechanism involved. For that purpose we subjected cardiomyocytes from transgenic mice (TG) with over-expression of SIRT6, to hypoxic stress in cell cultures. We hypothesized that cardiomyocytes from transgenic mice subjected to prolonged hypoxia may release survival factors or fewer damage markers to protect them from hypoxic stress compared with wild type (WT) mice. Lactate dehydrogenase (LDH) and creatine kinase (CK) released to the medium and propidium iodide (PI) binding, were markedly decreased following hypoxia in TG cardiomyocytes. The protective mechanism of SIRT6 over-expression includes the activation of pAMPKα pathway, the increased protein level of B-cell lymphoma 2 (Bcl2), the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), the decrease of reactive oxygen species (ROS) and the reduction in the protein level of phospho-protein kinase B (pAkt) during hypoxia. Together, all these processes impede the necrosis/apoptosis pathways leading to the improved survival of cardiomyocytes following hypoxia, which might explain life extension. - Highlights: • Sirtuin 6 is a protein associated with prolonged life expectancy. • Over-expression of sirtuin 6 protects cardiocytes from hypoxia and oxidative stress. • Over-expression of sirtuin 6 activates the pAMPKα pathway and the Bcl2 expression. • Over-expression of sirtuin 6 decreases ROS formation and pAkt level during hypoxia. • These pathways protect cardiocytes from hypoxia and might explain lifespan extension.

  7. Protein synthesis inhibitors attenuate water flow in vasopressin-stimulated toad urinary bladder

    International Nuclear Information System (INIS)

    Hoch, B.S.; Ast, M.B.; Fusco, M.J.; Jacoby, M.; Levine, S.D.

    1988-01-01

    Vasopressin stimulates the introduction of aggregated particles, which may represent pathways for water flow, into the luminal membrane of toad urinary bladder. It is not known whether water transport pathways are degraded on removal from membrane or whether they are recycled. The authors examined the effect of the protein synthesis inhibitors cycloheximide and puromycin using repeated 30-min cycles of vasopressin followed by washout of vasopressin, all in the presence of an osmotic gradient, a protocol that maximizes aggregate turnover. High dose cycloheximide inhibited flow immediately. Low dose cycloheximide did not affect initial flow. In the absence of vasopressin, inhibition did not develop. Despite the inhibition of flow in vasopressin-treated tissues, the cAMP-dependent protein kinase ratio was elevated in cycloheximide-treated tissues, suggesting modulation at a distal site in the stimulatory cascade. [ 14 C]urea permeability was not inhibited by cycloheximide. Puromycin also inhibited water flow by the fourth challenge with vasopressin. The data suggest that protein synthesis inhibitors attenuate flow at a site that is distal to cAMP-dependent protein kinase. However, the reversal of inhibition in MIX-treated tissues suggests that the water pathway can be fully manifested given suitable stimulation. They conclude that either large stores of the transport system are available or that the transport system is extensively recycled on retrieval from the membrane

  8. Asymmetric synthesis of a potent, aminopiperidine-fused imidazopyridine dipeptidyl peptidase IV inhibitor.

    Science.gov (United States)

    Xu, Feng; Corley, Edward; Zacuto, Michael; Conlon, David A; Pipik, Brenda; Humphrey, Guy; Murry, Jerry; Tschaen, David

    2010-03-05

    A practical asymmetric synthesis of a novel aminopiperidine-fused imidazopyridine dipeptidyl peptidase IV (DPP-4) inhibitor 1 has been developed. Application of a unique three-component cascade coupling with chiral nitro diester 7, which is easily accessed via a highly enantioselective Michael addition of dimethyl malonate to a nitrostyrene, allows for the assembly of the functionalized piperidinone skeleton in one pot. Through a base-catalyzed, dynamic crystallization-driven process, the cis-piperidionone 16a is epimerized to the desired trans isomer 16b, which is directly crystallized from the crude reaction stream in high yield and purity. Isomerization of the allylamide 16b in the presence of RhCl(3) is achieved without any epimerization of the acid/base labile stereogenic center adjacent to the nitro group on the piperidinone ring, while the undesired enamine intermediate is consumed to <0.5% by utilizing a trace amount of HCl generated from RhCl(3). The amino lactam 4, obtained through hydrogenation and hydrolysis, is isolated as its crystalline pTSA salt from the reaction solution directly, as such intramolecular transamidation has been dramatically suppressed via kinetic control. Finally, a Cu(I) catalyzed coupling-cyclization allows for the formation of the tricyclic structure of the potent DPP-4 inhibitor 1. The synthesis, which is suitable for large scale preparation, is accomplished in 23% overall yield.

  9. Fenofibrate inhibits atrial metabolic remodelling in atrial fibrillation through PPAR-α/sirtuin 1/PGC-1α pathway.

    Science.gov (United States)

    Liu, Guang-Zhong; Hou, Ting-Ting; Yuan, Yue; Hang, Peng-Zhou; Zhao, Jing-Jing; Sun, Li; Zhao, Guan-Qi; Zhao, Jing; Dong, Jing-Mei; Wang, Xiao-Bing; Shi, Hang; Liu, Yong-Wu; Zhou, Jing-Hua; Dong, Zeng-Xiang; Liu, Yang; Zhan, Cheng-Chuang; Li, Yue; Li, Wei-Min

    2016-03-01

    Atrial metabolic remodelling is critical for the process of atrial fibrillation (AF). The PPAR-α/sirtuin 1 /PPAR co-activator α (PGC-1α) pathway plays an important role in maintaining energy metabolism. However, the effect of the PPAR-α agonist fenofibrate on AF is unclear. Therefore, the aim of this study was to determine the effect of fenofibrate on atrial metabolic remodelling in AF and explore its possible mechanisms of action. The expression of metabolic proteins was examined in the left atria of AF patients. Thirty-two rabbits were divided into sham, AF (pacing with 600 beats·min(-1) for 1 week), fenofibrate treated (pretreated with fenofibrate before pacing) and fenofibrate alone treated (for 2 weeks) groups. HL-1 cells were subjected to rapid pacing in the presence or absence of fenofibrate, the PPAR-α antagonist GW6471 or sirtuin 1-specific inhibitor EX527. Metabolic factors, circulating biochemical metabolites, atrial electrophysiology, adenine nucleotide levels and accumulation of glycogen and lipid droplets were assessed. The PPAR-α/sirtuin 1/PGC-1α pathway was significantly inhibited in AF patients and in the rabbit/HL-1 cell models, resulting in a reduction of key downstream metabolic factors; this effect was significantly restored by fenofibrate. Fenofibrate prevented the alterations in circulating biochemical metabolites, reduced the level of adenine nucleotides and accumulation of glycogen and lipid droplets, reversed the shortened atrial effective refractory period and increased risk of AF. Fenofibrate inhibited atrial metabolic remodelling in AF by regulating the PPAR-α/sirtuin 1/PGC-1α pathway. The present study may provide a novel therapeutic strategy for AF. © 2016 The British Pharmacological Society.

  10. Synthesis and Structure-Activity Relationship of Griseofulvin Analogues as Inhibitors of Centrosomal Clustering in Cancer Cells

    DEFF Research Database (Denmark)

    Rønnest, Mads Holger; Rebacz, Blanka; Markworth, Lene

    2009-01-01

    Griseofulvin was identified as an inhibitor of centrosomal clustering in a recently developed assay. Centrosomal clustering is an important cellular event that enables bipolar mitosis for cancer cell lines harboring supernumerary centrosomes. We report herein the synthesis and SAR of 34 griseoful......Griseofulvin was identified as an inhibitor of centrosomal clustering in a recently developed assay. Centrosomal clustering is an important cellular event that enables bipolar mitosis for cancer cell lines harboring supernumerary centrosomes. We report herein the synthesis and SAR of 34...

  11. Synthesis and characterization of a novel organic corrosion inhibitor for mild steel in 1 M hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Mohammed H. Othman Ahmed

    2018-03-01

    Full Text Available The synthesis and characterization of a novel organic corrosion inhibitor (4-(3-mercapto-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-ylphenol, for mild steel in 1 M hydrochloric acid (HCl has been successfully reported for the first time. The inhibitor evaluated as corrosion inhibitor for mild steel in 1 M of Hydrochloric acid solution using electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurement techniques. Changes in the impedance parameters suggested an adsorption of the inhibitor onto the mild steel surface, leading to the formation of protective films. The results show that the inhibition efficiencies increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. The maximum inhibition efficiency up to 67% at the maximum concentration 0.5 mM. This shows that those inhibitors are effective in helping to reduce and slowing down the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing an organic inhibitor for the mild steel that can be weakened by increasing the temperature. The adsorption process of the synthesized organic inhibitor depends on its electronic characteristics in addition to steric effects and the nature of metal surface, temperature degree and the varying degrees of surface-site activity. The synthesized inhibitor molecules were absorbed by metal surface and follow Langmuir isotherms. Keywords: Corrosion, Inhibitor, Mild steel, EIS spectroscopy

  12. The Design, Synthesis and Structure-Activity Relationship of Mixed Serotonin, Norepinephrine and Dopamine Uptake Inhibitors

    Science.gov (United States)

    Chen, Zhengming; Yang, Ji; Skolnick, Phil

    The evolution of antidepressants over the past four decades has involved the replacement of drugs with a multiplicity of effects (e.g., TCAs) by those with selective actions (i.e., SSRIs). This strategy was employed to reduce the adverse effects of TCAs, largely by eliminating interactions with certain neurotransmitters or receptors. Although these more selective compounds may be better tolerated by patients, selective drugs, specifically SSRIs, are not superior to older drugs in treating depressed patients as measured by response and remission rates. It may be an advantage to increase synaptic levels of both serotonin and norepinephrine, as in the case of dual uptake inhibitors like duloxetine and venlafaxine. An important recent development has been the emergence of the triple-uptake inhibitors (TUIs/SNDRIs), which inhibit the uptake of the three neurotransmitters most closely linked to depression: serotonin, norepinephrine, and dopamine. Preclinical studies and clinical trials indicate that a drug inhibiting the reuptake of all three of these neurotransmitters could produce more rapid onset of action and greater efficacy than traditional antidepressants. This review will detail the medicinal chemistry involved in the design, synthesis and discovery of mixed serotonin, norepinephrine and dopamine transporter uptake inhibitors.

  13. Design, synthesis, and protein crystallography of biaryltriazoles as potent tautomerase inhibitors of macrophage migration inhibitory factor.

    Science.gov (United States)

    Dziedzic, Pawel; Cisneros, José A; Robertson, Michael J; Hare, Alissa A; Danford, Nadia E; Baxter, Richard H G; Jorgensen, William L

    2015-03-04

    Optimization is reported for biaryltriazoles as inhibitors of the tautomerase activity of human macrophage migration inhibitory factor (MIF), a proinflammatory cytokine associated with numerous inflammatory diseases and cancer. A combined approach was taken featuring organic synthesis, enzymatic assaying, crystallography, and modeling including free-energy perturbation (FEP) calculations. X-ray crystal structures for 3a and 3b bound to MIF are reported and provided a basis for the modeling efforts. The accommodation of the inhibitors in the binding site is striking with multiple hydrogen bonds and aryl-aryl interactions. Additional modeling encouraged pursuit of 5-phenoxyquinolinyl analogues, which led to the very potent compound 3s. Activity was further enhanced by addition of a fluorine atom adjacent to the phenolic hydroxyl group as in 3w, 3z, 3aa, and 3bb to strengthen a key hydrogen bond. It is also shown that physical properties of the compounds can be modulated by variation of solvent-exposed substituents. Several of the compounds are likely the most potent known MIF tautomerase inhibitors; the most active ones are more than 1000-fold more active than the well-studied (R)-ISO-1 and more than 200-fold more active than the chromen-4-one Orita-13.

  14. High glucose-induced oxidative stress represses sirtuin deacetylase expression and increases histone acetylation leading to neural tube defects.

    Science.gov (United States)

    Yu, Jingwen; Wu, Yanqing; Yang, Peixin

    2016-05-01

    Aberrant epigenetic modifications are implicated in maternal diabetes-induced neural tube defects (NTDs). Because cellular stress plays a causal role in diabetic embryopathy, we investigated the possible role of the stress-resistant sirtuin (SIRT) family histone deacetylases. Among the seven sirtuins (SIRT1-7), pre-gestational maternal diabetes in vivo or high glucose in vitro significantly reduced the expression of SIRT 2 and SIRT6 in the embryo or neural stem cells, respectively. The down-regulation of SIRT2 and SIRT6 was reversed by superoxide dismutase 1 (SOD1) over-expression in the in vivo mouse model of diabetic embryopathy and the SOD mimetic, tempol and cell permeable SOD, PEGSOD in neural stem cell cultures. 2,3-dimethoxy-1,4-naphthoquinone (DMNQ), a superoxide generating agent, mimicked high glucose-suppressed SIRT2 and SIRT6 expression. The acetylation of histone 3 at lysine residues 56 (H3K56), H3K14, H3K9, and H3K27, putative substrates of SIRT2 and SIRT6, was increased by maternal diabetes in vivo or high glucose in vitro, and these increases were blocked by SOD1 over-expression or tempol treatment. SIRT2 or SIRT6 over-expression abrogated high glucose-suppressed SIRT2 or SIRT6 expression, and prevented the increase in acetylation of their histone substrates. The potent sirtuin activator (SRT1720) blocked high glucose-increased histone acetylation and NTD formation, whereas the combination of a pharmacological SIRT2 inhibitor and a pan SIRT inhibitor mimicked the effect of high glucose on increased histone acetylation and NTD induction. Thus, diabetes in vivo or high glucose in vitro suppresses SIRT2 and SIRT6 expression through oxidative stress, and sirtuin down-regulation-induced histone acetylation may be involved in diabetes-induced NTDs. The mechanism underlying pre-gestational diabetes-induced neural tube defects (NTDs) is still elusive. Our study unravels a new epigenetic mechanism in which maternal diabetes-induced oxidative stress represses

  15. Synthesis and characterization of a novel organic corrosion inhibitor for mild steel in 1 M hydrochloric acid

    Science.gov (United States)

    Ahmed, Mohammed H. Othman; Al-Amiery, Ahmed A.; Al-Majedy, Yasmin K.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Gaaz, Tayser Sumer

    2018-03-01

    The synthesis and characterization of a novel organic corrosion inhibitor (4-(3-mercapto-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)phenol), for mild steel in 1 M hydrochloric acid (HCl) has been successfully reported for the first time. The inhibitor evaluated as corrosion inhibitor for mild steel in 1 M of Hydrochloric acid solution using electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurement techniques. Changes in the impedance parameters suggested an adsorption of the inhibitor onto the mild steel surface, leading to the formation of protective films. The results show that the inhibition efficiencies increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. The maximum inhibition efficiency up to 67% at the maximum concentration 0.5 mM. This shows that those inhibitors are effective in helping to reduce and slowing down the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing an organic inhibitor for the mild steel that can be weakened by increasing the temperature. The adsorption process of the synthesized organic inhibitor depends on its electronic characteristics in addition to steric effects and the nature of metal surface, temperature degree and the varying degrees of surface-site activity. The synthesized inhibitor molecules were absorbed by metal surface and follow Langmuir isotherms.

  16. Sirtuins and renal diseases: relationship with aging and diabetic nephropathy.

    Science.gov (United States)

    Kitada, Munehiro; Kume, Shinji; Takeda-Watanabe, Ai; Kanasaki, Keizo; Koya, Daisuke

    2013-02-01

    Sirtuins are members of the Sir2 (silent information regulator 2) family, a group of class III deacetylases. Mammals have seven different sirtuins, SIRT1-SIRT7. Among them, SIRT1, SIRT3 and SIRT6 are induced by calorie restriction conditions and are considered anti-aging molecules. SIRT1 has been the most extensively studied. SIRT1 deacetylates target proteins using the coenzyme NAD+ and is therefore linked to cellular energy metabolism and the redox state through multiple signalling and survival pathways. SIRT1 deficiency under various stress conditions, such as metabolic or oxidative stress or hypoxia, is implicated in the pathophysiologies of age-related diseases including diabetes, cardiovascular diseases, neurodegenerative disorders and renal diseases. In the kidneys, SIRT1 may inhibit renal cell apoptosis, inflammation and fibrosis, and may regulate lipid metabolism, autophagy, blood pressure and sodium balance. Therefore the activation of SIRT1 in the kidney may be a new therapeutic target to increase resistance to many causal factors in the development of renal diseases, including diabetic nephropathy. In addition, SIRT3 and SIRT6 are implicated in age-related disorders or longevity. In the present review, we discuss the protective functions of sirtuins and the association of sirtuins with the pathophysiology of renal diseases, including diabetic nephropathy.

  17. Synthesis of suicide inhibitors of monoamine oxidase: carbon-11 labeled clorgyline, L-deprenyl and D-deprenyl

    International Nuclear Information System (INIS)

    MacGregor, R.R.; Fowler, J.S.; Wolf, A.P.; Halldin, C.; Langstroem, B.

    1988-01-01

    The suicide inhibitors of monoamine oxidase type A and B, clorgyline and L-deprenyl have been labeled with carbon-11 by [ 11 C]methylation of the norbases with [ 11 C]H 3 I. The less active enantiomer of deprenyl (D-deprenyl) was also labeled using this procedure. The synthesis time was 35 minutes, the radiochemical yield was 25-40% and the specific activity was 0.8-2.0 Ci/μmol (calculated to EOB). Procedures for synthesis of the precursor norbases as well as the synthesis of unlabeled clorgyline, L-deprenyl and D-deprenyl are given. (author)

  18. Effects of ionizing radiations and of metabolic inhibitors on the synthesis of RNA in lymphocites bred in culture

    Energy Technology Data Exchange (ETDEWEB)

    Farulla, A; Alimena, G; Castagna, R; Naro, G; Percoco, V D [Rome Univ. (Italy)

    1954-01-01

    Studies are conducted of the activation kinetics of the RNA synthesis and of proteins, during their blasto transformation stage of human circulating lymphocytes in culture breeding and of the effects caused by some metabolic inhibitors and by ionizing radiations on RNA synthesis. The results obtained lead to assume that the initial activation concern RNA nuclear linkages with fast turnover and scarce sensibility to actinomycin and that the exposure to ionizing radiations causes a significant reduction of the RNA synthesis rate at the initial phases of the activation process while it hasn't any effect on the later stage.

  19. Different effects of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors on sterol synthesis in various human cell types

    NARCIS (Netherlands)

    Vliet, A.K. van; Thiel, G.C.F. van; Huisman, R.H.; Moshage, H.; Yap, S.H.; Cohen, L.H.

    1995-01-01

    The three vastatins examined, lovastatin, simvastatin and pravastatin, are equally strong inhibitors of the sterol synthesis in human hepatocytes in culture with IC50-values of 4.1, 8.0 and 2.0 nM, respectively. However, in the human extrahepatic cells: umbilical vascular endothelial cells, retinal

  20. Low survival of mice following lethal gamma-irradiation after administration of inhibitors of prostaglandin synthesis

    International Nuclear Information System (INIS)

    Hofer, M.; Pospisil, M.; Tkadlecek, L.; Viklicka, S.; Pipalova, I.; Hola, J.

    1992-01-01

    An impairment was observed of the survival of mice subjected to whole-body gamma-irradiation with a lethal dose of 10 Gy and treated with a repeated postirradiation administration of the prostaglandin synthesis inhibitors (PGSIs) indomethacin or diclofenac. Morphological examination of the gastrointestinal tract and estimation of the blood loss into its lumen in animals treated with diclofenac did not show serious damage such as hemorrhages or perforation, but revealed structural injury to the intestinal mucosa indicating inflammatory processes. The lesions found are supposed to be connected with increased intestinal permeability which leads to endotoxin escape from the gut and a subsequent increased mortality rate of irradiated animals. It may be concluded that PGSIs are not suitable for the management of radiation sickness after an exposure to lethal doses of ionizing radiation. (author) 2 tabs., 4 figs., 20 refs

  1. Ethylenediamine diacetate (EDDA) mediated synthesis of aurones under ultrasound: their evaluation as inhibitors of SIRT1.

    Science.gov (United States)

    Manjulatha, Khanapur; Srinivas, S; Mulakayala, Naveen; Rambabu, D; Prabhakar, M; Arunasree, Kalle M; Alvala, Mallika; Basaveswara Rao, M V; Pal, Manojit

    2012-10-01

    An improved synthesis of functionalized aurones has been accomplished via the reaction of benzofuran-3(2H)-one with a range of benzaldehydes in the presence of a mild base EDDA under ultrasound. A number of aurones were synthesized (within 5-30min) and the molecular structure of a representative compound determined by single crystal X-ray diffraction study confirmed Z-geometry of the C-C double bond present within the molecule. Some of the compounds synthesized have shown SIRT1 inhibiting as well as anti proliferative properties against two cancer cell lines in vitro. Compound 3a [(Z)-2-(5-bromo-2-hydroxybenzylidene) benzofuran-3(2H)-one] was identified as a potent inhibitor of SIRT1 (IC(50)=1μM) which showed a dose dependent increase in the acetylation of p53 resulting in induction of apoptosis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Small ring constrained peptidomimetics. Synthesis of epoxy peptidomimetics, inhibitors of cysteine proteases.

    Science.gov (United States)

    Demarcus, M; Ganadu, M L; Mura, G M; Porcheddu, A; Quaranta, L; Reginato, G; Taddei, M

    2001-02-09

    Different dipeptide analogues containing an oxirane ring in the place of the peptidic bond were prepared starting from naturally occurring amino acids. N-Fmoc-amino aldehydes were transformed into the corresponding methoxyvinyl derivatives through a Wittig reaction, and the addition of PhSeCl gave a series of different alpha-phenylselenyl aldehydes. Mukajiama reaction with silylketene acetals gave an intermediate product that was finally transformed into the desired oxiranyl peptidomimetics. Following this strategy we were able to control three new contiguous stereocenters starting from the enantiomerically pure amino acid. The dipeptide analogues could be used in SPPS on a SASRIN resin as the final epoxides were relatively unstable under acidic conditions. Moreover the synthesis of the single dipeptide mimetics was carried out on solid phase to generate a small library of epoxy peptidomimetics. Some of the products prepared in this work resulted as time-dependent reversible inhibitors of cysteine protease.

  3. Manipulating chromosome structure and metaphase status with ultraviolet light and repair synthesis inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Mullinger, A.M.; Johnson, R.T. (Cambridge Univ. (UK). Dept. of Zoology)

    1985-02-01

    DNA repair occurs in metaphase-arrested cells in response to ultraviolet irradiation. In the presence of the repair synthesis inhibitors, hydroxyurea and 1-..beta..-D-arabinofuranosylcytosine, the chromosomes of such cells are decondensed. The dose response of chromosome decondensation varies between different cell types. In human cells defective in excision repair there is much less chromosome decondensation in response to the same ultraviolet dose and time of repair inhibition. However, a simian virus 40-transformed muntjac cell displays pronounced chromosome decondensation but has limited incision ability. Both chromosome decondensation and single-strand break accumulation in the presence of inhibitors are reversed when DNA precursors are provided, but reversal after higher ultraviolet doses and longer period of incubation leads to recondensed chromosomes that are fragmented. Although the chromosomes of repair-inhibited metaphase cells are decondensed in fixed preparations, their morphology appears normal in intact cells. The cells also retain a capacity to induce prematurely condensed chromosomes (PCC) when fused with interphase cells: compared with control mitotic cells, the speed of induction is sometimes reduced but the final amount of PCC produced is similar.

  4. Design, synthesis, in vitro Evaluation and docking studies on dihydropyrimidine-based urease inhibitors.

    Science.gov (United States)

    Iftikhar, Fatima; Ali, Yousaf; Ahmad Kiani, Farooq; Fahad Hassan, Syed; Fatima, Tabeer; Khan, Ajmal; Niaz, Basit; Hassan, Abbas; Latif Ansari, Farzana; Rashid, Umer

    2017-10-01

    In our previous report, we have identified 3,4-dihydropyrimidine scaffold as promising class of urease inhibitor in a structure based virtual screen (SBVS) experiment. In present study, we attempted to optimize the scaffold by varying C-5 substituent. The elongation of the C-5 chain was achieved by the reaction of C-5 ester with hydrazine leading to C-5 carbohydrazides which were further used as building blocks for the synthesis of fifteen new compounds having diverse moieties. A significantly higher in vitro urease inhibitory activity with IC 50 values in submicromolar range was observed for semithiocarbazide derivatives (4a-c, 0.58-0.79µM) and isatin Schiff base derivative 5a (0.23µM). Docking analysis suggests that the synthesized compounds were anchored well in the catalytic site and extending to the entrance of binding pocket and thus restrict the mobility of the flap by interacting with its key amino acid residues. The overall results of urease inhibition have shown that these compounds can be further optimized and developed as lead urease inhibitors. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Synthesis and Application of Phenyl Nitrone Derivatives as Acidic and Microbial Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    Shijun Chen

    2015-01-01

    Full Text Available Nitrone has drawn great attention due to its wide applications as a 1,3-dipole in heterocyclic compounds synthesis and the bioactivities. With the special structure, nitrone can also be used as ligand in inorganic chemistry. Based on the current research, the nitrones are anticipated to be effective inhibitors against acidic and microbial corrosion. The aim of this work is to investigate the inhibitory action of nitrones. In this work, a series of phenyl nitrone derivatives (PN was synthesized and used as acidic and microbial corrosion inhibitors. The results indicate that several compounds show moderate to high inhibition efficiency (IE in 3% HCl. Accompanied with HMTA or BOZ, the IEs greatly increase, and the highest efficiency of 98.5% was obtained by using PN4 + BOZ. Investigation of the antibacterial activity against oilfield microorganism shows that the nitrone derivatives can inhibit SRB, IB, and TGB with moderate to high efficiency under 1,000 mg/L, which makes them potential to be used as bifunctional oilfield chemicals.

  6. Inhibitors of the Hydrolytic Enzyme Dimethylarginine Dimethylaminohydrolase (DDAH: Discovery, Synthesis and Development

    Directory of Open Access Journals (Sweden)

    Rhys B. Murphy

    2016-05-01

    Full Text Available Dimethylarginine dimethylaminohydrolase (DDAH is a highly conserved hydrolytic enzyme found in numerous species, including bacteria, rodents, and humans. In humans, the DDAH-1 isoform is known to metabolize endogenous asymmetric dimethylarginine (ADMA and monomethyl arginine (l-NMMA, with ADMA proposed to be a putative marker of cardiovascular disease. Current literature reports identify the DDAH family of enzymes as a potential therapeutic target in the regulation of nitric oxide (NO production, mediated via its biochemical interaction with the nitric oxide synthase (NOS family of enzymes. Increased DDAH expression and NO production have been linked to multiple pathological conditions, specifically, cancer, neurodegenerative disorders, and septic shock. As such, the discovery, chemical synthesis, and development of DDAH inhibitors as potential drug candidates represent a growing field of interest. This review article summarizes the current knowledge on DDAH inhibition and the derived pharmacokinetic parameters of the main DDAH inhibitors reported in the literature. Furthermore, current methods of development and chemical synthetic pathways are discussed.

  7. The NADPH oxidase inhibitor apocynin induces nitric oxide synthesis via oxidative stress

    International Nuclear Information System (INIS)

    Riganti, Chiara; Costamagna, Costanzo; Doublier, Sophie; Miraglia, Erica; Polimeni, Manuela; Bosia, Amalia; Ghigo, Dario

    2008-01-01

    We have recently shown that apocynin elicits an oxidative stress in N11 mouse glial cells and other cell types. Here we report that apocynin increased the accumulation of nitrite, the stable derivative of nitric oxide (NO), in the extracellular medium of N11 cell cultures, and the NO synthase (NOS) activity in cell lysates. The increased synthesis of NO was associated with increased expression of inducible NOS (iNOS) mRNA, increased nuclear translocation of the redox-sensitive transcription factor NF-κB and decreased intracellular level of its inhibitor IkBα. These effects, accompanied by increased production of H 2 O 2 , were very similar to those observed after incubation with bacterial lipopolysaccharide (LPS) and were inhibited by catalase. These results suggest that apocynin, similarly to LPS, induces increased NO synthesis by eliciting a generation of reactive oxygen species (ROS), which in turn causes NF-κB activation and increased expression of iNOS. Therefore, the increased bioavailability of NO reported in the literature after in vivo or in vitro treatments with apocynin might depend, at least partly, on the drug-elicited induction of iNOS, and not only on the inhibition of NADPH oxidase and the subsequent decreased scavenging of NO by oxidase-derived ROS, as it is often supposed

  8. Design, Synthesis and Biological Evaluation of Histone Deacetylase (HDAC) Inhibitors: Saha (Vorinostat) Analogs and Biaryl Indolyl Benzamide Inhibitors Display Isoform Selectivity

    Science.gov (United States)

    Negmeldin, Ahmed Thabet

    HDAC proteins have emerged as interesting targets for anti-cancer drugs due to their involvement in cancers, as well as several other diseases. Several HDAC inhibitors have been approved by the FDA as anti-cancer drugs, including SAHA (suberoylanilide hydroxamic acid, Vorinostat). Unfortunately, SAHA inhibits most HDAC isoforms, which limit its use as a pharmacological tool and may lead to side effects in the clinic. In this work we were interested in developing isoform selective HDAC inhibitors, which may decrease or eliminate the side effects associated with non-selective inhibitors treatment. In addition, isoform selective HDAC inhibitors can be used as biological tools to help understand the HDAC-related cancer biology. Our strategy was based on synthesis and screening of several derivatives of the non-selective FDA approved drug SAHA substituted at different positions of the linker region. Several SAHA analogs modified at the C4 and C5 positions of the linker were synthesized. The new C4- and C5-modified SAHA libraries, along with the previously synthesized C2-modified SAHA analogs were screened in vitro and in cellulo for HDAC isoform selectivity. Interestingly, several analogs exhibited dual HDAC6/HDAC8 selectivity. Enantioselective syntheses of the pure enantiomers of some of the interesting analogs were performed and the enantiomers were screened in vitro. Among the most interesting analogs, ( R)-C4-benzyl SAHA displayed 520- to 1300-fold selectivity for HDAC6 and HDAC8 over HDAC1, 2, and 3, with IC50 values of 48 and 27 nM with HDAC6 and 8, respectively. Docking studies were performed to provide structural rationale for the observed selectivity of the new analogs. In addition, rational design, synthesis, and screening of several other biaryl indolyl benzamide HDAC inhibitors is discussed, and some showed modest HDAC1 selectivity. The new biaryl indolyl benzamides can be useful to further develop HDAC1 selective inhibitors. The dual HDAC6/8 selective

  9. Synthesis of the proteinase inhibitor LEKTI domain 6 by the fragment condensation method and regioselective disulfide bond formation.

    Science.gov (United States)

    Vasileiou, Zoe; Barlos, Kostas K; Gatos, Dimitrios; Adermann, Knut; Deraison, Celine; Barlos, Kleomenis

    2010-01-01

    Proteinase inhibitors are of high pharmaceutical interest and are drug candidates for a variety of indications. Specific kallikrein inhibitors are important for their antitumor activity and their potential application to the treatment of skin diseases. In this study we describe the synthesis of domain 6 of the kallikrein inhibitor Lympho-Epithilial Kazal-Type Inhibitor (LEKTI) by the fragment condensation method and site-directed cystine bridge formation. To obtain the linear LEKTI precursor, the condensation was best performed in solution, coupling the protected fragment 1-22 to 23-68. This method yielded LEKTI domain 6 of high purity and equipotent to the recombinantly produced peptide. (c) 2010 Wiley Periodicals, Inc.

  10. Direct observation of the effects of cellulose synthesis inhibitors using live cell imaging of Cellulose Synthase (CESA) in Physcomitrella patens.

    Science.gov (United States)

    Tran, Mai L; McCarthy, Thomas W; Sun, Hao; Wu, Shu-Zon; Norris, Joanna H; Bezanilla, Magdalena; Vidali, Luis; Anderson, Charles T; Roberts, Alison W

    2018-01-15

    Results from live cell imaging of fluorescently tagged Cellulose Synthase (CESA) proteins in Cellulose Synthesis Complexes (CSCs) have enhanced our understanding of cellulose biosynthesis, including the mechanisms of action of cellulose synthesis inhibitors. However, this method has been applied only in Arabidopsis thaliana and Brachypodium distachyon thus far. Results from freeze fracture electron microscopy of protonemal filaments of the moss Funaria hygrometrica indicate that a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB), fragments CSCs and clears them from the plasma membrane. This differs from Arabidopsis, in which DCB causes CSC accumulation in the plasma membrane and a different cellulose synthesis inhibitor, isoxaben, clears CSCs from the plasma membrane. In this study, live cell imaging of the moss Physcomitrella patens indicated that DCB and isoxaben have little effect on protonemal growth rates, and that only DCB causes tip rupture. Live cell imaging of mEGFP-PpCESA5 and mEGFP-PpCESA8 showed that DCB and isoxaben substantially reduced CSC movement, but had no measureable effect on CSC density in the plasma membrane. These results suggest that DCB and isoxaben have similar effects on CSC movement in P. patens and Arabidopsis, but have different effects on CSC intracellular trafficking, cell growth and cell integrity in these divergent plant lineages.

  11. Angiotensin converting enzyme inhibitors mitigate collagen synthesis induced by a single dose of radiation to the whole thorax

    International Nuclear Information System (INIS)

    Kma, L.; Gao, F.; Fish, B.L.; Moulder, J.E.; Jacobs, E.R.; Medhora, M.

    2012-01-01

    Our long-term goal is to use angiotensin converting enzyme (ACE) inhibitors to mitigate the increase in lung collagen synthesis that is induced by irradiation to the lung, which could result from accidental exposure or radiological terrorism. Rats (WAG/RijCmcr) were given a single dose of 13 Gy (dose rate of 1.43 Gy/min) of X-irradiation to the thorax. Three structurally-different ACE inhibitors, captopril, enalapril and fosinopril were provided in drinking water beginning 1 week after irradiation. Rats that survived acute pneumonitis (at 6-12 weeks) were evaluated monthly for synthesis of lung collagen. Other endpoints included breathing rate, wet to dry lung weight ratio, and analysis of lung structure. Treatment with captopril (145-207 mg/m 2 /day) or enalapril (19-28 mg/m 2 /day), but not fosinopril (19-28 mg/m 2 /day), decreased morbidity from acute pneumonitis. Lung collagen in the surviving irradiated rats was increased over that of controls by 7 months after irradiation. This increase in collagen synthesis was not observed in rats treated with any of the three ACE inhibitors. Analysis of the lung morphology at 7 months supports the efficacy of ACE inhibitors against radiation-induced fibrosis. The effectiveness of fosinopril against fibrosis, but not against acute pneumonitis, suggests that pulmonary fibrosis may not be a simple consequence of injury during acute pneumonitis. In summary, three structurally-different ACE inhibitors mitigate the increase in collagen synthesis 7 months following irradiation of the whole thorax and do so, even when therapy is started one week after irradiation. (author)

  12. Sirtuins: Novel targets for metabolic disease in drug development

    International Nuclear Information System (INIS)

    Jiang Weijian

    2008-01-01

    Calorie restriction extends lifespan and produces a metabolic profile desirable for treating diseases such as type 2 diabetes. SIRT1, an NAD + -dependent deacetylase, is a principal modulator of pathways downstream of calorie restriction that produces beneficial effects on glucose homeostasis and insulin sensitivity. Activation of SIRT1 leads to enhanced activity of multiple proteins, including peroxisome proliferator-activated receptor coactivator-1α (PGC-1α) and FOXO which helps to mediate some of the in vitro and in vivo effects of sirtuins. Resveratrol, a polyphenolic SIRT1 activator, mimics the effects of calorie restriction in lower organisms and in mice fed a high-fat diet ameliorates insulin resistance. In this review, we summarize recent research advances in unveiling the molecular mechanisms that underpin sirtuin as therapeutic candidates and discuss the possibility of using resveratrol as potential drug for treatment of diabetes

  13. A SARS-coronovirus 3CL protease inhibitor isolated from the marine sponge Axinella cf. corrugata: structure elucidation and synthesis

    International Nuclear Information System (INIS)

    Lira, Simone P. de; Seleghim, Mirna H.R.; Berlinck, Roberto G.S.

    2007-01-01

    Two coumarin derivatives, esculetin-4-carboxylic acid methyl ester (1) and esculetin-4- carboxylic acid ethyl ester (2), have been isolated from the marine sponge Axinella cf. corrugata. Structure determination included analysis of spectroscopic data and total synthesis of compound 2. These are the first coumarin derivatives isolated from a marine sponge. The ethyl ester 2 was found to be an in vitro inhibitor of SARS 3CL-protease and an effective inhibitor of SARS-CoV replication in Vero cells at non-cytotoxic concentrations. (author)

  14. Sensitization of human cells by inhibitors of DNA synthesis following the action of DNA-damaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Filatov, M.V.; Noskin, L.A. (Leningrad Inst. of Nuclear Physics, Gatchina (USSR))

    1983-08-01

    Inhibitors of DNA synthesis 1-..beta..-arabinofuranosylcytosine (Ac) and hydroxyurea (Hu) taken together drastically sensitized human cells to the killing effect of DNA-damaging agents. For UV-irradiation this sensitization depended on the cells' ability for excision repair. By using viscoelastometric methods of measurement of double-strand breaks (DSB) in the genome, it was established that the first DSB were generated after incubation of the damaged cells in the mixture of inhibitors at about the same dose when sensitization appeared. A scheme is proposed to describe molecular events associated with the phenomenon studied. 35 refs.

  15. Sirtuins and Their Roles in Brain Aging and Neurodegenerative Disorders.

    Science.gov (United States)

    Jęśko, Henryk; Wencel, Przemysław; Strosznajder, Robert P; Strosznajder, Joanna B

    2017-03-01

    Sirtuins (SIRT1-SIRT7) are unique histone deacetylases (HDACs) whose activity depends on NAD + levels and thus on the cellular metabolic status. SIRTs regulate energy metabolism and mitochondrial function. They orchestrate the stress response and damage repair. Through these functions sirtuins modulate the course of aging and affect neurodegenerative diseases. SIRTSs interact with multiple signaling proteins, transcription factors (TFs) and poly(ADP-ribose) polymerases (PARPs) another class of NAD + -dependent post-translational protein modifiers. The cross-talk between SIRTs TFs and PARPs is a highly promising research target in a number of brain pathologies. This review describes updated results on sirtuins in brain aging/neurodegeneration. It focuses on SIRT1 but also on the roles of mitochondrial SIRTs (SIRT3, 4, 5) and on SIRT6 and SIRT2 localized in the nucleus and in cytosol, respectively. The involvement of SIRTs in regulation of insulin-like growth factor signaling in the brain during aging and in Alzheimer's disease was also focused. Moreover, we analyze the mechanism(s) and potential significance of interactions between SIRTs and several TFs in the regulation of cell survival and death. A critical view is given on the application of SIRT activators/modulators in therapy of neurodegenerative diseases.

  16. Design and synthesis of new esters of terpenoid alcohols as 15-lipoxygenase inhibitors

    Directory of Open Access Journals (Sweden)

    Hamid Sadeghian

    2018-07-01

    Full Text Available Objective(s: 15-Lipoxygenases are one of the iron-containing proteins capable of performing peroxidation of unsaturated fatty acids in animals and plants. The critical role of enzymes in the formation of inflammations, sensitivities, and some cancers has been demonstrated in mammals. The importance of enzymes has led to the development of mechanistic studies, product analysis, and synthesis of inhibitors. Materials and Methods: The inhibitory activity of all synthetic compounds against SLO (soybean 15-lipoxygenase: L1; EC 1,13,11,12 was determined using the peroxide formation method. In this method, the basis of evaluation of lipoxygenase activity is measuring the concentration of fatty acid peroxide. All measurements were compared with  4-​methyl-​2-​(4-​methylpiperazinylpyrimido[4,​5-​b]benzothiazine (4-MMPB as one of the known lipoxygenase inhibitors. The radical scavenging ability of all synthetic compounds using stable free radicals (DPPH: 2,2-diphenyl-1-picrylhydrazyl was measured for further investigation.Results: In this study, a series of esters from phenolic acids with terpenoid alcohols was synthesized and their inhibitory potency against soybean 15-lipoxygenase and their free radical scavenging properties were determined. Among the synthetic compounds, adamantyl protocatetuate 2j and bornyl protocatetuate 2o showed the most potent inhibitory activity with IC50 values of 0.95 and 0.78 μm, respectively.Conclusion: By changing the alcohol and acyl portions of stylosin, it was found that electronic properties play main role in lipoxygenase inhibition potency in contrast with steric features. Insertion of more reductive phenolic moiety such as catechuate and gallate lead to more lipoxygenase inhibition potency of the esters as observed in their radical scavenging activity.

  17. Synthesis, Pharmacological Profile and Docking Studies of New Sulfonamides Designed as Phosphodiesterase-4 Inhibitors.

    Directory of Open Access Journals (Sweden)

    Isabelle Karine da Costa Nunes

    Full Text Available Prior investigations showed that increased levels of cyclic AMP down-regulate lung inflammatory changes, stimulating the interest in phosphodiesterase (PDE4 as therapeutic target. Here, we described the synthesis, pharmacological profile and docking properties of a novel sulfonamide series (5 and 6a-k designed as PDE4 inhibitors. Compounds were screened for their selectivity against the four isoforms of human PDE4 using an IMAP fluorescence polarized protocol. The effect on allergen- or LPS-induced lung inflammation and airway hyper-reactivity (AHR was studied in A/J mice, while the xylazine/ketamine-induced anesthesia test was employed as a behavioral correlate of emesis in rodents. As compared to rolipram, the most promising screened compound, 6a (LASSBio-448 presented a better inhibitory index concerning PDE4D/PDE4A or PDE4D/PDE4B. Accordingly, docking analyses of the putative interactions of LASSBio-448 revealed similar poses in the active site of PDE4A and PDE4C, but slight unlike orientations in PDE4B and PDE4D. LASSBio-448 (100 mg/kg, oral, 1 h before provocation, inhibited allergen-induced eosinophil accumulation in BAL fluid and lung tissue samples. Under an interventional approach, LASSBio-448 reversed ongoing lung eosinophilic infiltration, mucus exacerbation, peribronchiolar fibrosis and AHR by allergen provocation, in a mechanism clearly associated with blockade of pro-inflammatory mediators such as IL-4, IL-5, IL-13 and eotaxin-2. LASSBio-448 (2.5 and 10 mg/kg also prevented inflammation and AHR induced by LPS. Finally, the sulfonamide derivative was shown to be less pro-emetic than rolipram and cilomilast in the assay employed. These findings suggest that LASSBio-448 is a new PDE4 inhibitor with marked potential to prevent and reverse pivotal pathological features of diseases characterized by lung inflammation, such as asthma.

  18. Expression of Sirtuins in the Retinal Neurons of Mice, Rats, and Humans

    Directory of Open Access Journals (Sweden)

    Hongdou Luo

    2017-11-01

    Full Text Available Sirtuins are a class of histone deacetylases (HDACs that have been shown to regulate a range of pathophysiological processes such as cellular aging, inflammation, metabolism, and cell proliferation. There are seven mammalian Sirtuins (SIRT1-7 that play important roles in stress response, aging, and neurodegenerative diseases. However, the location and function of Sirtuins in neurons are not well defined. This study assessed the retinal expression of Sirtuins in mice, rats, and humans and measured the expression of Sirtuins in aged and injured retinas. Expression of all 7 Sirtuins was confirmed by Western blot and Real-Time PCR analysis in all three species. SIRT1 is highly expressed in mouse, rat, and human retinas, whereas SIRT2-7 expression was relatively lower in human retinas. Immunofluorescence was also used to examine the expression and localization of Sirtuins in rat retinal neurons. Importantly, we demonstrate a marked reduction of SIRT1 expression in aged retinal neurons as well as retinas injured by acute ischemia-reperfusion. On the other hand, none of the other Sirtuins exhibit any significant age-related changes in expression except for SIRT5, which was significantly higher in the retinas of adults compared to both young and aged rats. Our work presents the first composite analysis of Sirtuins in the retinal neurons of mice, rats, and humans, and suggests that increasing the expression and activity of SIRT1 may be beneficial for the treatment of glaucoma and other age-related eye dysfunction.

  19. Microwave-Assisted Synthesis of a MK2 Inhibitor by Suzuki-Miyaura Coupling for Study in Werner Syndrome Cells

    Directory of Open Access Journals (Sweden)

    Mark C. Bagley

    2015-06-01

    Full Text Available Microwave-assisted Suzuki-Miyaura cross-coupling reactions have been employed towards the synthesis of three different MAPKAPK2 (MK2 inhibitors to study accelerated aging in Werner syndrome (WS cells, including the cross-coupling of a 2-chloroquinoline with a 3-pyridinylboronic acid, the coupling of an aryl bromide with an indolylboronic acid and the reaction of a 3-amino-4-bromopyrazole with 4-carbamoylphenylboronic acid. In all of these processes, the Suzuki-Miyaura reaction was fast and relatively efficient using a palladium catalyst under microwave irradiation. The process was incorporated into a rapid 3-step microwave-assisted method for the synthesis of a MK2 inhibitor involving 3-aminopyrazole formation, pyrazole C-4 bromination using N-bromosuccinimide (NBS, and Suzuki-Miyaura cross-coupling of the pyrazolyl bromide with 4-carbamoylphenylboronic acid to give the target 4-arylpyrazole in 35% overall yield, suitable for study in WS cells.

  20. Potential inhibitors of dapE and argE enzymes as the new antimicrobial agents: Synthesis and characterization

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Jan; Pícha, Jan; Vaněk, Václav; Jiráček, Jiří; Slaninová, Jiřina; Fučík, Vladimír; Holz, R. C.

    2008-01-01

    Roč. 14, č. 8 (2008), s. 83-84 ISSN 1075-2617. [European Peptide Symposium /30./. 31.08.2008-05.09.2008, Helsinki] R&D Projects: GA AV ČR IAA400550614 Institutional research plan: CEZ:AV0Z40550506 Keywords : antimicrobial agents * dapE and argE inhibitors * synthesis and activity Subject RIV: CC - Organic Chemistry

  1. Imidazopyridine-based inhibitors of glycogen synthase kinase 3: synthesis and evaluation of amide isostere replacements of the carboxamide scaffold.

    Science.gov (United States)

    Yngve, Ulrika; Söderman, Peter; Svensson, Mats; Rosqvist, Susanne; Arvidsson, Per I

    2012-11-01

    In this study, we explored the effect of bioisostere replacement in a series of glycogen synthase kinase 3 (GSK3) inhibitors based on the imidazopyridine core. The synthesis and biological evaluation of a number of novel sulfonamide, 1,2,4-oxadiazole, and thiazole derivates as amide bioisosteres, as well as a computational rationalization of the obtained results are reported. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

  2. Stereoselective synthesis of an active metabolite of the potent PI3 kinase inhibitor PKI-179.

    Science.gov (United States)

    Chen, Zecheng; Venkatesan, Aranapakam M; Dos Santos, Osvaldo; Delos Santos, Efren; Dehnhardt, Christoph M; Ayral-Kaloustian, Semiramis; Ashcroft, Joseph; McDonald, Leonard A; Mansour, Tarek S

    2010-03-05

    The synthesis and stereochemical determination of 1-(4-(4-((1R,5R,6R)-6-hydroxy-3-oxa-8-azabicyclo[3.2.1]octan-8-yl)-6-morpholino-1,3,5-triazin-2-yl)phenyl)-3-(pyridin-4-yl)urea (2), an active metabolite of the potent PI3 kinase inhibitor PKI-179 (1), is described. Stereospecific hydroboration of the double bond of 2,5-dihydro-1H-pyrrole 8 gave the 2,3-trans alcohol 9 exclusively. The configuration of the 3-hydroxyl group in 9 was inverted by an oxidation and stereoselective reduction sequence to give the corresponding 2,3-cis isomer 23. Both exo (21) and endo (27) isomers of the metabolite 2 were prepared via a practical synthetic route from 9 and 23, respectively, and the stereochemistry of 2 was determined to be endo. The endo isomer (27) was separated into two enantiomers 28 and 29 by chiral HPLC. Compound 2 was found to be enantiomerically pure and identical to the enantiomer 28. The absolute stereochemistry of the enantiomer 28 was determined by Mosher's method, thus establishing the stereochemistry of the active metabolite 2.

  3. Synthesis of three bromophenols from red algae as PTP1B inhibitors

    Science.gov (United States)

    Guo, Shuju; Li, Jing; Li, Ting; Shi, Dayong; Han, Lijun

    2011-01-01

    Bromophenols are a set of natural products widely distributed in seaweed, most of which exhibit interesting and useful biological activities. To develop a reliable and efficient synthetic route to these natural bromophenols, three of them, 3,4-dibromo-5-(2'-bromo-3',4'-dihydroxy-6'-methoxymethyl-benzyl)-benzene-1,2-diol (compound 9), 3,4-dibromo-5-(2'-bromo-6'-ethoxy methyl-3',4'-dihydroxybenzyl)-benzene-1,2-diol (compound 10), and 3-bromo-4-(3'-bromo-4',5'-dihydroxy benzyl)-5-(ethoxymethyl)-benzene-1,2-diol (compound 14), isolated from red marine algae, have been synthesized in eight steps with an overall yield of 14.4%, 14.4%, and 18.2% respectively, via a practical approach employing bromination, Wolff-Kishner-Huang reduction and a Friedel-Crafts reaction as key steps. The protein tyrosine phosphatase 1B (PTP1B) inhibitory activities of the synthetic compounds were evaluated by the colorimetric assay. The results show that these compounds are moderate PTP1B inhibitors. The synthesis of these bromophenol derivatives makes in vivo studies of their structure-activity relationships and inhibition activity against PTP1B possible.

  4. Genetic basis of Spodoptera frugiperda (Lepidoptera: Noctuidae) resistance to the chitin synthesis inhibitor lufenuron.

    Science.gov (United States)

    do Nascimento, Antonio Rogério Bezerra; Farias, Juliano Ricardo; Bernardi, Daniel; Horikoshi, Renato Jun; Omoto, Celso

    2016-04-01

    An understanding of the genetic basis of insect resistance to insecticides is important for the establishment of insect resistance management (IRM) strategies. In this study we evaluated the inheritance pattern of resistance to the chitin synthesis inhibitor lufenuron in Spodoptera frugiperda. The LC50 values (95% CI) were 0.23 µg lufenuron mL(-1) water (ppm) (0.18-0.28) for the susceptible strain (SUS) and 210.6 µg mL(-1) (175.90-258.10) for the lufenuron-resistant strain (LUF-R), based on diet-overlay bioassay. The resistance ratio was ≈ 915-fold. The LC50 values for reciprocal crosses were 4.89 µg mL(-1) (3.79-5.97) for female LUF-R and male SUS and 5.74 µg mL(-1) (4.70-6.91) for female SUS and male LUF-R, indicating that the inheritance of S. frugiperda resistance to lufenuron is an autosomal, incompletely recessive trait. Backcrosses of the progeny of reciprocal crosses with the parental LUF-R showed a polygenic effect. The estimated minimum number of independent segregations was in the 11.02 range, indicating that resistance to lufenuron is associated with multiple genes in S. frugiperda. Based on genetic crosses, the inheritance pattern of lufenuron resistance in S. frugiperda was autosomal, incompletely recessive and polygenic. Implications of this finding to IRM are discussed in this paper. © 2015 Society of Chemical Industry.

  5. Synthesis and bioevaluation of new tacrine-cinnamic acid hybrids as cholinesterase inhibitors against Alzheimer's disease.

    Science.gov (United States)

    Chen, Yao; Zhu, Jie; Mo, Jun; Yang, Hongyu; Jiang, Xueyang; Lin, Hongzhi; Gu, Kai; Pei, Yuqiong; Wu, Liang; Tan, Renxiang; Hou, Jing; Chen, Jingyi; Lv, Yang; Bian, Yaoyao; Sun, Haopeng

    2018-12-01

    Small molecule cholinesterases inhibitor (ChEI) provides an effective therapeutic strategy to treat Alzheimer's disease (AD). Currently, the discovery of new ChEI with multi-target effect is still of great importance. Herein, we report the synthesis, structure-activity relationship study and biological evaluation of a series of tacrine-cinnamic acid hybrids as new ChEIs. All target compounds are evaluated for their in vitro cholinesterase inhibitory activities. The representatives which show potent activity on cholinesterase, are evaluated for the amyloid β-protein self-aggregation inhibition and in vivo assays. The optimal compound 19, 27, and 30 (human AChE IC 50  = 10.2 ± 1.2, 16.5 ± 1.7, and 15.3 ± 1.8 nM, respectively) show good performance in ameliorating the scopolamine-induced cognition impairment and preliminary safety in hepatotoxicity evaluation. These compounds deserve further evaluation for the development of new therapeutic agents against AD.

  6. The glutathione synthesis inhibitor buthionine sulfoximine synergistically enhanced melphalan activity against preclinical models of multiple myeloma

    International Nuclear Information System (INIS)

    Tagde, A; Singh, H; Kang, M H; Reynolds, C P

    2014-01-01

    Melphalan (L-PAM) has been an integral part of multiple myeloma (MM) treatment as a conditioning regimen before stem cell transplant (SCT). After initial response, most treated patients experience relapse with an aggressive phenotype. Increased glutathione (GSH) in MM may mediate resistance to L-PAM. We demonstrated that the GSH synthesis inhibitor buthionine sulfoximine (BSO) synergistically enhanced L-PAM activity (inducing 2–4 logs of cell kill) against nine MM cell lines (also in the presence of marrow stroma or cytokines) and in seven primary MM samples (combination indices <1.0). In MM cell lines, BSO significantly (P<0.05) depleted GSH, increased L-PAM-induced single-strand DNA breaks, mitochondrial depolarization, caspase cleavage and apoptosis. L-PAM depleted GSH, but GSH rapidly recovered in a L-PAM-resistant MM cell line unless also treated with BSO. Treatment with N-acetylcysteine antagonized BSO+L-PAM cytotoxicity without increasing GSH. In human MM xenografted into beige-nude-xid mice, BSO significantly depleted MM intracellular GSH and significantly increased apoptosis compared with L-PAM alone. BSO+L-PAM achieved complete responses (CRs) in three MM xenograft models including maintained CRs >100 days, and significantly increased the median event-free survival relative to L-PAM alone. Combining BSO with L-PAM warrants clinical testing in advanced MM

  7. A new class of HIV-1 protease inhibitor: the crystallographic structure, inhibition and chemical synthesis of an aminimide peptide isostere.

    Science.gov (United States)

    Rutenber, E E; McPhee, F; Kaplan, A P; Gallion, S L; Hogan, J C; Craik, C S; Stroud, R M

    1996-09-01

    The essential role of HIV-1 protease (HIV-1 PR) in the viral life cycle makes it an attractive target for the development of substrate-based inhibitors that may find efficacy as anti-AIDS drugs. However, resistance has arisen to potent peptidomimetic drugs necessitating the further development of novel chemical backbones for diversity based chemistry focused on probing the active site for inhibitor interactions and binding modes that evade protease resistance. AQ148 is a potent inhibitor of HIV-1 PR and represents a new class of transition state analogues incorporating an aminimide peptide isostere. A 3-D crystallographic structure of AQ148, a tetrapeptide isostere, has been determined in complex with its target HIV-1 PR to a resolution of 2.5 A and used to evaluate the specific structural determinants of AQ148 potency and to correlate structure-activity relationships within the class of related compounds. AQ148 is a competitive inhibitor of HIV-1 PR with a Ki value of 137 nM. Twenty-nine derivatives have been synthesized and chemical modifications have been made at the P1, P2, P1', and P2' sites. The atomic resolution structure of AQ148 bound to HIV-1 PR reveals both an inhibitor binding mode that closely resembles that of other peptidomimetic inhibitors and specific protein/inhibitor interactions that correlate with structure-activity relationships. The structure provides the basis for the design, synthesis and evaluation of the next generation of hydroxyethyl aminimide inhibitors. The aminimide peptide isostere is a scaffold with favorable biological properties well suited to both the combinatorial methods of peptidomimesis and the rational design of potent and specific substrate-based analogues.

  8. Targeting tumor-initiating cells: Eliminating anabolic cancer stem cells with inhibitors of protein synthesis or by mimicking caloric restriction

    Science.gov (United States)

    Lamb, Rebecca; Harrison, Hannah; Smith, Duncan L.; Townsend, Paul A.; Jackson, Thomas; Ozsvari, Bela; Martinez-Outschoorn, Ubaldo E.; Pestell, Richard G.; Howell, Anthony; Lisanti, Michael P.; Sotgia, Federica

    2015-01-01

    We have used an unbiased proteomic profiling strategy to identify new potential therapeutic targets in tumor-initiating cells (TICs), a.k.a., cancer stem cells (CSCs). Towards this end, the proteomes of mammospheres from two breast cancer cell lines were directly compared to attached monolayer cells. This allowed us to identify proteins that were highly over-expressed in CSCs and/or progenitor cells. We focused on ribosomal proteins and protein folding chaperones, since they were markedly over-expressed in mammospheres. Overall, we identified >80 molecules specifically associated with protein synthesis that were commonly upregulated in mammospheres. Most of these proteins were also transcriptionally upregulated in human breast cancer cells in vivo, providing evidence for their potential clinical relevance. As such, increased mRNA translation could provide a novel mechanism for enhancing the proliferative clonal expansion of TICs. The proteomic findings were functionally validated using known inhibitors of protein synthesis, via three independent approaches. For example, puromycin (which mimics the structure of tRNAs and competitively inhibits protein synthesis) preferentially targeted CSCs in both mammospheres and monolayer cultures, and was ~10-fold more potent for eradicating TICs, than “bulk” cancer cells. In addition, rapamycin, which inhibits mTOR and hence protein synthesis, was very effective at reducing mammosphere formation, at nanomolar concentrations. Finally, mammosphere formation was also markedly inhibited by methionine restriction, which mimics the positive effects of caloric restriction in cultured cells. Remarkably, mammosphere formation was >18-fold more sensitive to methionine restriction and replacement, as directly compared to monolayer cell proliferation. Methionine is absolutely required for protein synthesis, since every protein sequence starts with a methionine residue. Thus, the proliferation and survival of CSCs is very sensitive to

  9. A modified approach to 2-(N-aryl)-1,3-oxazoles: application to the synthesis of the IMPDH inhibitor BMS-337197 and analogues.

    Science.gov (United States)

    Dhar, T G Murali; Guo, Junqing; Shen, Zhongqi; Pitts, William J; Gu, Henry H; Chen, Bang-Chi; Zhao, Rulin; Bednarz, Mark S; Iwanowicz, Edwin J

    2002-06-13

    [structure: see text] A modified approach to the synthesis of 2-(N-aryl)-1,3-oxazoles, employing an optimized iminophosphorane/heterocumulene-mediated methodology, and its application to the synthesis of BMS-337197, a potent inhibitor of IMPDH, are described.

  10. Substrates for Efficient Fluorometric Screening Employing the NAD-Dependent Sirtuin 5 Lysine Deacylase (KDAC) Enzyme

    DEFF Research Database (Denmark)

    Madsen, Andreas Stahl; Olsen, Christian Adam

    2012-01-01

    The class III lysine deacylases (KDACs), also known as the sirtuins, have emerged as interesting drug targets for therapeutic intervention in a variety of diseases. To gain a deeper understanding of the processes affected by sirtuins, the development of selective small molecule modulators of indi...

  11. Synthesis and PET studies of [(11)C-cyano]letrozole (Femara), an aromatase inhibitor drug.

    Science.gov (United States)

    Kil, Kun-Eek; Biegon, Anat; Ding, Yu-Shin; Fischer, Andre; Ferrieri, Richard A; Kim, Sung Won; Pareto, Deborah; Schueller, Michael J; Fowler, Joanna S

    2009-02-01

    Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone into estrone and estradiol, respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole; Femara) is a high-affinity aromatase inhibitor (K(i)=11.5 nM) that has Food and Drug Administration approval for breast cancer treatment. Here we report the synthesis of carbon-11-labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile) were prepared in a two-step synthesis from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [(11)C]cyano group was introduced via tetrakis(triphenylphosphine)palladium(0)-catalyzed coupling of [(11)C]cyanide with the bromo precursor. Positron emission tomography (PET) studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. Log D, the free fraction of letrozole in plasma and the [(11)C-cyano]letrozole fraction in arterial plasma were also measured. [(11)C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79-80%, with a radiochemical purity greater than 98% and a specific activity of 4.16+/-2.21 Ci/mumol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance, followed by slow clearance of carbon-11 from the brain, with no difference between brain regions. Brain kinetics was not affected by coinjection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9%, and log D was 1.84. [(11)C-cyano]Letrozole is readily synthesized via a palladium-catalyzed coupling reaction with [(11)C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase, as revealed by the absence of regional specificity and saturability in brain regions such as amygdala, which are known to

  12. Synthesis and PET studies of [{sup 11}C-cyano]letrozole (Femara), an aromatase inhibitor drug

    Energy Technology Data Exchange (ETDEWEB)

    Kil, Kun-Eek [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, Stony Brook University, Stony Brook, NY 11794 (United States); Biegon, Anat [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Ding, Yu-Shin [Department of Radiology, Yale University School of Medicine, New Haven, CT 06520-8048 (United States); Fischer, Andre [Johannes-Gutenberg Universitaet Mainz, Institut fuer Organische Chemie, 55128 Mainz (Germany); Ferrieri, Richard A.; Kim, Sung Won; Pareto, Deborah; Schueller, Michael J. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Fowler, Joanna S. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, Stony Brook University, Stony Brook, NY 11794 (United States)], E-mail: fowler@bnl.gov

    2009-02-15

    Introduction: Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone into estrone and estradiol, respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole; Femara) is a high-affinity aromatase inhibitor (K{sub i}=11.5 nM) that has Food and Drug Administration approval for breast cancer treatment. Here we report the synthesis of carbon-11-labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods: Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile) were prepared in a two-step synthesis from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [{sup 11}C]cyano group was introduced via tetrakis(triphenylphosphine)palladium(0)-catalyzed coupling of [{sup 11}C]cyanide with the bromo precursor. Positron emission tomography (PET) studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. Log D, the free fraction of letrozole in plasma and the [{sup 11}C-cyano]letrozole fraction in arterial plasma were also measured. Results: [{sup 11}C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79-80%, with a radiochemical purity greater than 98% and a specific activity of 4.16{+-}2.21 Ci/{mu}mol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance, followed by slow clearance of carbon-11 from the brain, with no difference between brain regions. Brain kinetics was not affected by coinjection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9%, and log D was 1.84. Conclusion: [{sup 11}C-cyano]Letrozole is readily synthesized via a palladium-catalyzed coupling reaction with [{sup 11}C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase, as revealed by the absence of regional specificity

  13. Effects of inhibitors of protein synthesis and intracellular transport on the gamma-aminobutyric acid agonist-induced functional differentiation of cultured cerebellar granule cells

    DEFF Research Database (Denmark)

    Belhage, B; Hansen, Gert Helge; Meier, E

    1990-01-01

    The effect of inhibitors of protein synthesis (actinomycin D, cycloheximide), proteases (leupeptin), and intracellular transport (colchicine, monensin) on the gamma-aminobutyric acid (GABA) agonist [4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP)]-induced changes in morphological...... an intracellular and a plasma membrane localization of the receptors. In all experiments cultures treated with THIP alone served as controls. The inhibitors of protein synthesis totally abolished the ability of THIP to induce low-affinity GABA receptors. In contrast, the inhibitors of intracellular transport...

  14. Potent New Small-Molecule Inhibitor of Botulinum Neurotoxin Serotype A Endopeptidase Developed by Synthesis-Based Computer-Aided Molecular Design

    Science.gov (United States)

    2009-11-01

    simulations; (4) synthesis and evaluation of the molecules from Step 2 or 3 (e.g., synthesizing and testing AHP). From synthetic chemistry point of view...2000) Synthesis of 6H-indolo [2,3-b][1,6]naphthyridines and related compounds as the 5-Aza analogues of ellipticine alkaloids . J Org Chem 65: 7977–7983...Potent New Small-Molecule Inhibitor of Botulinum Neurotoxin Serotype A Endopeptidase Developed by Synthesis -Based Computer-Aided Molecular Design

  15. Investigating the Sensitivity of NAD+-dependent Sirtuin Deacylation Activities to NADH

    DEFF Research Database (Denmark)

    Madsen, Andreas Stahl; Andersen, Christian; Daoud, Mohammad Mahdi

    2016-01-01

    Protein lysine posttranslational modification by an increasing number of different acyl groups is becoming appreciated as a regulatory mechanism in cellular biology. Sirtuins are class III histone deacylases that use NAD+ as a co-substrate during amide bond hydrolysis. Several studies have...... described the sirtuins as sensors of the NAD+/NADH ratio, but it has not been formally tested for all the mammalian sirtuins in vitro. To address this problem, we first synthesized a wide variety of peptide-based probes, which were used to identify the range of hydrolytic activities of human sirtuins...... to be prone to hydrolytic cleavage by SIRT1-3 and SIRT6, supporting recent findings. We then tested the ability of NADH, ADP-ribose, and nicotinamide to inhibit these NAD+-dependent deacylase activities of the sirtuins. In the commonly used 7-amino-4-methylcoumarin-coupled fluorescence-based assay...

  16. Exploration of the Fluorescent Properties and the Modulated Activities against Sirtuin Fluorogenic Assays of Chromenone-Derived Natural Products

    Directory of Open Access Journals (Sweden)

    Hui Wen

    2018-05-01

    Full Text Available Chromenone-derived natural products include chromones (flavone, isoflavone and coumarins. Chromenone compounds not only exhibit impressive biological activities, but also are an important resource of experimentally used fluorophores, such as, 7-amino-4-methylcoumarin (AMC. Various chromenone compounds have reported to have weak fluorescence, and this has the potential to interfere with the measurements during AMC fluorogenic assays and result in non-robust assay readouts. Several flavones and isoflavones were found as SIRT1 activators, while fluorogenic sirtuin assays utilized AMC labelled peptides as the substrates. In this study we investigated whether the fluorescent properties of chromenone-derived natural products interrupt the measurement of SIRT1/2 modulated activities. We found that the reported SIRT1 activators: flavones were detected with the SIRT1 activation activity, but isoflavones were not detected with SIRT1 activation activity, and instead that they were found to be fluorogenic compounds. Another chromenone compound, osthole, exhibited a moderate SIRT2 inhibitory activity with an IC50 of 10 μM. In conclusion, the fluorescent properties of these chromenone compounds do affect the measurement of the sirtuin activities of both inhibitors and activators. However, if the possible fluorescence properties are mitigated in the assay readout, these fluorogenic assays enable the screening of activity modulators.

  17. Effects of indomethacin, NS-398 (a selective prostaglandin H synthase-2 inhibitor) and protein synthesis inhibitors on prostaglandin production by the guinea-pig placenta.

    Science.gov (United States)

    Aitken, H; Poyser, N L

    2001-01-01

    The outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)were similar from the day 22 guinea-pig placenta and sub-placenta in culture, except for PGE2 output from the sub-placenta which was lower. Between days 22 and 29 of pregnancy, the outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)during the initial 2 h culture period increased 6.9-, 1.1- and 3.2-fold, respectively, from the placenta, and 2.1-, 1.4- and 2.2-fold, respectively, from the sub-placenta. Therefore, there was a relatively specific increase in PGF(2 alpha)production by the guinea-pig placenta between days 22 and 29 of pregnancy. The output of PGFM from the cultured placenta also increased between days 22 and 29, indicating that the increase in PGF(2 alpha)output was due to increased synthesis rather than to decreased metabolism. By comparing the amounts of prostaglandins produced by tissue homogenates during a 1 h incubation period, it appears that there is approximately a 2-fold increase in the amount of prostaglandin H synthase (PGHS) present in the guinea-pig placenta between days 22 and 29. NS-398 (a specific inhibitor of PGHS-2) and indomethacin (an inhibitor of both PGHS-1 and PGHS-2) both inhibited prostaglandin production by homogenates of day 22 and day 29 placenta. Indomethacin was more effective than NS-398, except for their actions on PGF(2 alpha)production by the day 29 placenta where indomethacin and NS-398 were equiactive. Indomethacin and NS-398 were both very effective at inhibiting the outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)from the day 22 and day 29 placenta and sub-placenta in culture, indicating that prostaglandin production by the guinea-pig placenta and sub-placenta in culture is largely dependent upon the activity of PGHS-2. The high production of PGF(2 alpha)by the day 29 placenta is not dependent on the continual synthesis of fresh protein(s), as inhibitors of protein synthesis did not reduce PGF(2 alpha)output from the day 29 guinea-pig placenta in culture

  18. Sirtuins in the Cardiovascular System: Potential Targets in Pediatric Cardiology.

    Science.gov (United States)

    Ianni, Alessandro; Yuan, Xuejun; Bober, Eva; Braun, Thomas

    2018-06-01

    Cardiovascular diseases represent a major cause of death and morbidity. Cardiac and vascular pathologies develop predominantly in the aged population in part due to lifelong exposure to numerous risk factors but are also found in children and during adolescence. In comparison to adults, much has to be learned about the molecular pathways driving cardiovascular diseases in the pediatric population. Sirtuins are highly conserved enzymes that play pivotal roles in ensuring cardiac homeostasis under physiological and stress conditions. In this review, we discuss novel findings about the biological functions of these molecules in the cardiovascular system and their possible involvement in pediatric cardiovascular diseases.

  19. Probing the Influence of Linker Length and Flexibility in the Design and Synthesis of New Trehalase Inhibitors

    Directory of Open Access Journals (Sweden)

    Giampiero D’Adamio

    2018-02-01

    Full Text Available This work aims to synthesize new trehalase inhibitors selective towards the insect trehalase versus the porcine trehalase, in view of their application as potentially non-toxic insecticides and fungicides. The synthesis of a new pseudodisaccharide mimetic 8, by means of a stereoselective α-glucosylation of the key pyrrolizidine intermediate 13, was accomplished. The activity of compound 8 as trehalase inhibitor towards C. riparius trehalase was evaluated and the results showed that 8 was active in the μM range and showed a good selectivity towards the insect trehalase. To reduce the overall number of synthetic steps, simpler and more flexible disaccharide mimetics 9–11 bearing a pyrrolidine nucleus instead of the pyrrolizidine core were synthesized. The biological data showed the key role of the linker chain’s length in inducing inhibitory properties, since only compounds 9 (α,β-mixture, bearing a two-carbon atom linker chain, maintained activity as trehalase inhibitors. A proper change in the glucosyl donor-protecting groups allowed the stereoselective synthesis of the β-glucoside 9β, which was active in the low micromolar range (IC50 = 0.78 μM and 12-fold more potent (and more selective than 9α towards the insect trehalase.

  20. Mitochondrial toxicity of selective COX-2 inhibitors via inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria

    DEFF Research Database (Denmark)

    Syed, Muzeeb; Skonberg, Christian; Hansen, Steen Honoré

    2016-01-01

    Cyclooxygenase-2 (COX-2) inhibitors (coxibs) are non-steroidal anti-inflammatory drugs (NSAIDs) designed to selectively inhibit COX-2. However, drugs of this therapeutic class are associated with drug induced liver injury (DILI) and mitochondrial injury is likely to play a role. The effects...... of selective COX-2 inhibitors on inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria were investigated. The order of potency of inhibition of ATP synthesis was: lumiracoxib (IC50: 6.48 ± 2.74 μM)>celecoxib (IC50: 14.92 ± 6.40 μM)>valdecoxib (IC50: 161.4 ± 28.6 μM)>rofecoxib (IC50...... correlation (with r(2)=0.921) was observed between the potency of inhibition of ATP synthesis and the log P values. The in vitro metabolism of coxibs in rat liver mitochondria yielded for each drug substance a major single metabolite and identified a hydroxy metabolite with each of the coxibs...

  1. Design, Synthesis and Biological Activity of Novel Reversible Peptidyl FVIIa Inhibitors Rh-Catalyzed Enantioselective Synthesis of Diaryl Amines

    DEFF Research Database (Denmark)

    Storgaard, Morten

    functional group tolerance. Unfortunately, these -aryl tetramic acids were too unreactive and ring opening toward the synthesis of the building block did not succeed. However, -aryl tetramic acids are still interesting compounds due to their potential biological activity. The building block 3.15 (P1......-catalyzed enantioselective synthesis of diaryl amines, which is an important class of compounds (Chapter 4). For example it is found in the third generation anti-histaminic agent levocetirizine. Development of efficient synthetic routes is therefore of considerably interest. The rhodium-catalyzed enantioselective synthesis...

  2. Regulation of Sirtuin-Mediated Protein Deacetylation by Cardioprotective Phytochemicals

    Directory of Open Access Journals (Sweden)

    Niria Treviño-Saldaña

    2017-01-01

    Full Text Available Modulation of posttranslational modifications (PTMs, such as protein acetylation, is considered a novel therapeutic strategy to combat the development and progression of cardiovascular diseases. Protein hyperacetylation is associated with the development of numerous cardiovascular diseases, including atherosclerosis, hypertension, cardiac hypertrophy, and heart failure. In addition, decreased expression and activity of the deacetylases Sirt1, Sirt3, and Sirt6 have been linked to the development and progression of cardiac dysfunction. Several phytochemicals exert cardioprotective effects by regulating protein acetylation levels. These effects are mainly exerted via activation of Sirt1 and Sirt3 and inhibition of acetyltransferases. Numerous studies support a cardioprotective role for sirtuin activators (e.g., resveratrol, as well as other emerging modulators of protein acetylation, including curcumin, honokiol, oroxilyn A, quercetin, epigallocatechin-3-gallate, bakuchiol, tyrosol, and berberine. Studies also point to a cardioprotective role for various nonaromatic molecules, such as docosahexaenoic acid, alpha-lipoic acid, sulforaphane, and caffeic acid ethanolamide. Here, we review the vast evidence from the bench to the clinical setting for the potential cardioprotective roles of various phytochemicals in the modulation of sirtuin-mediated deacetylation.

  3. Regulation of Sirtuin-Mediated Protein Deacetylation by Cardioprotective Phytochemicals

    Science.gov (United States)

    2017-01-01

    Modulation of posttranslational modifications (PTMs), such as protein acetylation, is considered a novel therapeutic strategy to combat the development and progression of cardiovascular diseases. Protein hyperacetylation is associated with the development of numerous cardiovascular diseases, including atherosclerosis, hypertension, cardiac hypertrophy, and heart failure. In addition, decreased expression and activity of the deacetylases Sirt1, Sirt3, and Sirt6 have been linked to the development and progression of cardiac dysfunction. Several phytochemicals exert cardioprotective effects by regulating protein acetylation levels. These effects are mainly exerted via activation of Sirt1 and Sirt3 and inhibition of acetyltransferases. Numerous studies support a cardioprotective role for sirtuin activators (e.g., resveratrol), as well as other emerging modulators of protein acetylation, including curcumin, honokiol, oroxilyn A, quercetin, epigallocatechin-3-gallate, bakuchiol, tyrosol, and berberine. Studies also point to a cardioprotective role for various nonaromatic molecules, such as docosahexaenoic acid, alpha-lipoic acid, sulforaphane, and caffeic acid ethanolamide. Here, we review the vast evidence from the bench to the clinical setting for the potential cardioprotective roles of various phytochemicals in the modulation of sirtuin-mediated deacetylation. PMID:29234485

  4. Sirtuins and Proteolytic Systems: Implications for Pathogenesis of Synucleinopathies

    Directory of Open Access Journals (Sweden)

    Belém Sampaio-Marques

    2015-05-01

    Full Text Available Insoluble and fibrillar forms of α-synuclein are the major components of Lewy bodies, a hallmark of several sporadic and inherited neurodegenerative diseases known as synucleinopathies. α-Synuclein is a natural unfolded and aggregation-prone protein that can be degraded by the ubiquitin-proteasomal system and the lysosomal degradation pathways. α-Synuclein is a target of the main cellular proteolytic systems, but it is also able to alter their function further, contributing to the progression of neurodegeneration. Aging, a major risk for synucleinopathies, is associated with a decrease activity of the proteolytic systems, further aggravating this toxic looping cycle. Here, the current literature on the basic aspects of the routes for α-synuclein clearance, as well as the consequences of the proteolytic systems collapse, will be discussed. Finally, particular focus will be given to the sirtuins’s role on proteostasis regulation, since their modulation emerged as a promising therapeutic strategy to rescue cells from α-synuclein toxicity. The controversial reports on the potential role of sirtuins in the degradation of α-synuclein will be discussed. Connection between sirtuins and proteolytic systems is definitely worth of further studies to increase the knowledge that will allow its proper exploration as new avenue to fight synucleinopathies.

  5. Potential New H1N1 Neuraminidase Inhibitors from Ferulic Acid and Vanillin: Molecular Modelling, Synthesis and in Vitro Assay

    Science.gov (United States)

    Hariono, Maywan; Abdullah, Nurshariza; Damodaran, K. V.; Kamarulzaman, Ezatul E.; Mohamed, Nornisah; Hassan, Sharifah Syed; Shamsuddin, Shaharum; Wahab, Habibah A.

    2016-12-01

    We report the computational and experimental efforts in the design and synthesis of novel neuraminidase (NA) inhibitors from ferulic acid and vanillin. Two proposed ferulic acid analogues, MY7 and MY8 were predicted to inhibit H1N1 NA using molecular docking. From these two analogues, we designed, synthesised and evaluated the biological activities of a series of ferulic acid and vanillin derivatives. The enzymatic H1N1 NA inhibition assay showed MY21 (a vanillin derivative) has the lowest IC50 of 50 μM. In contrast, the virus inhibition assay showed MY15, a ferulic acid derivative has the best activity with the EC50 of ~0.95 μM. Modelling studies further suggest that these predicted activities might be due to the interactions with conserved and essential residues of NA with ΔGbind values comparable to those of oseltamivir and zanamivir, the two commercial NA inhibitors.

  6. Inhibitors of HIV-protease from computational design. A history of theory and synthesis still to be fully appreciated.

    Science.gov (United States)

    Berti, Federico; Frecer, Vladimir; Miertus, Stanislav

    2014-01-01

    Despite the fact that HIV-Protease is an over 20 years old target, computational approaches to rational design of its inhibitors still have a great potential to stimulate the synthesis of new compounds and the discovery of new, potent derivatives, ever capable to overcome the problem of drug resistance. This review deals with successful examples of inhibitors identified by computational approaches, rather than by knowledge-based design. Such methodologies include the development of energy and scoring functions, docking protocols, statistical models, virtual combinatorial chemistry. Computations addressing drug resistance, and the development of related models as the substrate envelope hypothesis are also reviewed. In some cases, the identified structures required the development of synthetic approaches in order to obtain the desired target molecules; several examples are reported.

  7. Synthesis, structure-activity relationship, and pharmacological profile of analogs of the ASIC-3 inhibitor A-317567.

    Science.gov (United States)

    Kuduk, Scott D; Di Marco, Christina N; Bodmer-Narkevitch, Vera; Cook, Sean P; Cato, Matthew J; Jovanovska, Aneta; Urban, Mark O; Leitl, Michael; Sain, Nova; Liang, Annie; Spencer, Robert H; Kane, Stefanie A; Hartman, George D; Bilodeau, Mark T

    2010-01-20

    The synthesis, structure-activity relationship (SAR), and pharmacological evaluation of analogs of the acid-sensing ion channel (ASIC) inhibitor A-317567 are reported. It was found that the compound with an acetylenic linkage was the most potent ASIC-3 channel blocker. This compound reversed mechanical hypersensitivity in the rat iodoacetate model of osteoarthritis pain, although sedation was noted. Sedation was also observed in ASIC-3 knockout mice, questioning whether sedation and antinociception are mediated via a non-ASIC-3 specific mechanism.

  8. The design and synthesis of novel SGLT2 inhibitors: C-glycosides with benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties.

    Science.gov (United States)

    Guo, Cheng; Hu, Min; DeOrazio, Russell J; Usyatinsky, Alexander; Fitzpatrick, Kevin; Zhang, Zhenjun; Maeng, Jun-Ho; Kitchen, Douglas B; Tom, Susan; Luche, Michele; Khmelnitsky, Yuri; Mhyre, Andrew J; Guzzo, Peter R; Liu, Shuang

    2014-07-01

    The sodium glucose co-transporter 2 (SGLT2) has received considerable attention in recent years as a target for the treatment of type 2 diabetes mellitus. This report describes the design, synthesis and structure-activity relationship (SAR) of C-glycosides with benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties as novel SGLT2 inhibitors. Compounds 5p and 33b demonstrated high potency in inhibiting SGLT2 and high selectivity against SGLT1. The in vitro ADMET properties of these compounds will also be discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Total synthesis and structural revision of TMG-chitotriomycin, a specific inhibitor of insect and fungal beta-N-acetylglucosaminidases.

    Science.gov (United States)

    Yang, You; Li, Yao; Yu, Biao

    2009-09-02

    TMG-chitotriomycin, a potent and selective inhibitor of the beta-N-acetylglucosaminidases that possesses an unique N,N,N-trimethyl-d-glucosamine (TMG) residue, is revised to be the TMG-beta-(1-->4)-chitotriose instead of the originally proposed alpha-anomer via its total synthesis, for which a highly convergent approach was developed in which the sterically demanding (1-->4)-glycosidic linkages are efficiently constructed by the Au(I)-catalyzed glycosylation protocol with glycosyl o-hexynylbenzoates as donors.

  10. Design, Synthesis and in vitro Biochemical Activity of Novel Amino Acid Sulfonohydrazide Inhibitors of MurC.

    Science.gov (United States)

    Frlan, Rok; Kovač, Andreja; Blanot, Didier; Gobec, Stanislav; Pečar, Slavko; Obreza, Aleš

    2011-06-01

    Mur ligases are essential enzymes involved in the cytoplasmic steps of peptidoglycan synthesis which remain attractive, yet unexploited targets. In order to develop new antibacterial agents, we have designed a series of new MurC and MurD inhibitors bearing amino acid sulfonohydrazide moiety. The L-Leu series of this class displayed the highest enzyme inhibition with IC50 in the concentration range between 100 and 500 µM, with L-Thr, L-Pro and L-Ala derivatives being inactive. The most promising compound of the series also expressed weak antibacterial activity against S. aureus with MIC = 128 µg/mL.

  11. A chiral synthesis of dapoxetine hydrochloride, a serotonin re-uptake inhibitor, and its 14C isotopomer

    International Nuclear Information System (INIS)

    Wheeler, W.J.; O'Bannon, D.D.

    1992-01-01

    The 14 C-isotopmer of dapoxetine-[ 14 C] HCl (S (+) -N,N-dimethyl-α[2-(1-naphthalenyloxy)ethyl-2- 14 C]benzenemeth a-n amine hydrochloride, 1a), a potent serotonin re-uptake inhibitor has been prepared by a chiral synthesis, starting with tert. -butyloxyphenylglycine (3). Borane reduction, followed by activation of the resulting alcohol 4 as its mesylate 5b, provided the chiral starting material. The radiolabel was introduced by reaction of 5b with sodium cyanide-[ 14 C]. The desired product (1) was then elaborated from nitrile 6a,b via a five step synthesis in an overall 19.5% radiochemical yield. (Author)

  12. Synthesis and biological evaluation of several dephosphonated analogues of CMP-Neu5Ac as inhibitors of GM3-synthase.

    Science.gov (United States)

    Rota, Paola; Cirillo, Federica; Piccoli, Marco; Gregorio, Antonio; Tettamanti, Guido; Allevi, Pietro; Anastasia, Luigi

    2015-10-05

    Previous studies demonstrated that reducing the GM3 content in myoblasts increased the cell resistance to hypoxic stress, suggesting that a pharmacological inhibition of the GM3 synthesis could be instrumental for the development of new treatments for ischemic diseases. Herein, the synthesis of several dephosphonated CMP-Neu5Ac congeners and their anti-GM3-synthase activity is reported. Biological activity testes revealed that some inhibitors almost completely blocked the GM3-synthase activity in vitro and reduced the GM3 content in living embryonic kidney 293A cells, eventually activating the epidermal growth factor receptor (EGFR) signaling cascade. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Aflatoxin-exposure of Vibrio gazogenes as a novel system for the generation of aflatoxin synthesis inhibitors

    Directory of Open Access Journals (Sweden)

    Phani M Gummadidala

    2016-06-01

    Full Text Available Aflatoxin is a mycotoxin and a secondary metabolite, and the most potent known liver carcinogen that contaminates several important crops, and represents a significant threat to public health and the economy. Available approaches reported thus far have been insufficient to eliminate this threat, and therefore provide the rational to explore novel methods for preventing aflatoxin accumulation in the environment. Many terrestrial plants and microbes that share ecological niches and encounter the aflatoxin producers have the ability to synthesize compounds that inhibit aflatoxin synthesis. However, reports of natural aflatoxin inhibitors from marine ecosystem components that do not share ecological niches with the aflatoxin producers are rare. Here we show that a non-pathogenic marine bacterium, Vibrio gazogenes, when exposed to low non-toxic doses of aflatoxin B1, demonstrates a shift in its metabolic output and synthesizes a metabolite fraction that inhibits aflatoxin synthesis without affecting hyphal growth in the model aflatoxin producer, Aspergillus parasiticus. The molecular mass of the predominant metabolite in this fraction was also different from the known prodigiosins, which are the known antifungal secondary metabolites synthesized by this Vibrio. Gene expression analyses using RT-PCR demonstrate that this metabolite fraction inhibits aflatoxin synthesis by down-regulating the expression of early-, middle- and late- growth stage aflatoxin genes, the aflatoxin pathway regulator, aflR and one global regulator of secondary metabolism, LaeA. Our study establishes a novel system for generation of aflatoxin synthesis inhibitors, and emphasizes the potential of the under-explored Vibrio’s silent genome for generating new modulators of fungal secondary metabolism.

  14. Sirtuin 1 stimulates the proliferation and the expression of glycolysis genes in pancreatic neoplastic lesions.

    Science.gov (United States)

    Pinho, Andreia V; Mawson, Amanda; Gill, Anthony; Arshi, Mehreen; Warmerdam, Max; Giry-Laterriere, Marc; Eling, Nils; Lie, Triyana; Kuster, Evelyne; Camargo, Simone; Biankin, Andrew V; Wu, Jianmin; Rooman, Ilse

    2016-11-15

    Metabolic reprogramming is a feature of neoplasia and tumor growth. Sirtuin 1 (SIRT1) is a lysine deacetylase of multiple targets including metabolic regulators such as p53. SIRT1 regulates metaplasia in the pancreas. Nevertheless, it is unclear if SIRT1 affects the development of neoplastic lesions and whether metabolic gene expression is altered.To assess neoplastic lesion development, mice with a pancreas-specific loss of Sirt1 (Pdx1-Cre;Sirt1-lox) were bred into a KrasG12D mutant background (KC) that predisposes to the development of pancreatic intra-epithelial neoplasia (PanIN) and ductal adenocarcinoma (PDAC). Similar grade PanIN lesions developed in KC and KC;Sirt1-lox mice but specifically early mucinous PanINs occupied 40% less area in the KC;Sirt1-lox line, attributed to reduced proliferation. This was accompanied by reduced expression of proteins in the glycolysis pathway, such as GLUT1 and GAPDH.The stimulatory effect of SIRT1 on proliferation and glycolysis gene expression was confirmed in a human PDAC cell line. In resected PDAC samples, higher proliferation and expression of glycolysis genes correlated with poor patient survival. SIRT1 expression per se was not prognostic but low expression of Cell Cycle and Apoptosis Regulator 2 (CCAR2), a reported SIRT1 inhibitor, corresponded to poor patient survival.These findings open perspectives for novel targeted therapies in pancreatic cancer.

  15. Sirtuin 1 stimulates the proliferation and the expression of glycolysis genes in pancreatic neoplastic lesions

    Science.gov (United States)

    Pinho, Andreia V.; Mawson, Amanda; Gill, Anthony; Arshi, Mehreen; Warmerdam, Max; Giry-Laterriere, Marc; Eling, Nils; Lie, Triyana; Kuster, Evelyne; Camargo, Simone; Biankin, Andrew V.; Wu, Jianmin; Rooman, Ilse

    2016-01-01

    Metabolic reprogramming is a feature of neoplasia and tumor growth. Sirtuin 1 (SIRT1) is a lysine deacetylase of multiple targets including metabolic regulators such as p53. SIRT1 regulates metaplasia in the pancreas. Nevertheless, it is unclear if SIRT1 affects the development of neoplastic lesions and whether metabolic gene expression is altered. To assess neoplastic lesion development, mice with a pancreas-specific loss of Sirt1 (Pdx1-Cre;Sirt1-lox) were bred into a KrasG12D mutant background (KC) that predisposes to the development of pancreatic intra-epithelial neoplasia (PanIN) and ductal adenocarcinoma (PDAC). Similar grade PanIN lesions developed in KC and KC;Sirt1-lox mice but specifically early mucinous PanINs occupied 40% less area in the KC;Sirt1-lox line, attributed to reduced proliferation. This was accompanied by reduced expression of proteins in the glycolysis pathway, such as GLUT1 and GAPDH. The stimulatory effect of SIRT1 on proliferation and glycolysis gene expression was confirmed in a human PDAC cell line. In resected PDAC samples, higher proliferation and expression of glycolysis genes correlated with poor patient survival. SIRT1 expression per se was not prognostic but low expression of Cell Cycle and Apoptosis Regulator 2 (CCAR2), a reported SIRT1 inhibitor, corresponded to poor patient survival. These findings open perspectives for novel targeted therapies in pancreatic cancer. PMID:27494892

  16. Insight the C-site pocket conformational changes responsible for sirtuin 2 activity using molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Sugunadevi Sakkiah

    Full Text Available Sirtuin belongs to a family of typical histone deacetylase which regulates the fundamental cellular biological processes including gene expression, genome stability, mitosis, nutrient metabolism, aging, mitochondrial function, and cell motility. Michael et. al. reported that B-site mutation (Q167A and H187A decreased the SIRT2 activity but still the structural changes were not reported. Hence, we performed 5 ns molecular dynamics (MD simulation on SIRT2 Apo-form and complexes with substrate/NAD(+ and inhibitor of wild type (WT, Q167A, and H187A. The results revealed that the assembly and disassembly of C-site induced by presence of substrate/NAD(+ and inhibitor, respectively. This assembly and disassembly was mainly due to the interaction between the substrate/NAD(+ and inhibitor and F96 and the distance between F96 and H187 which are present at the neck of the C-site. MD simulations suggest that the conformational change of L3 plays a major role in assembly and disassembly of C-site. Our current results strongly suggest that the distinct conformational change of L3 as well as the assembly and disassembly of C-site plays an important role in SIRT2 deacetylation function. Our study unveiled the structural changes of SIRT2 in presence of NAD(+ and inhibitor which should be helpful to improve the inhibitory potency of SIRT2.

  17. The Sensitivity of Memory Consolidation and Reconsolidation to Inhibitors of Protein Synthesis and Kinases: Computational Analysis

    Science.gov (United States)

    Zhang, Yili; Smolen, Paul; Baxter, Douglas A.; Byrne, John H.

    2010-01-01

    Memory consolidation and reconsolidation require kinase activation and protein synthesis. Blocking either process during or shortly after training or recall disrupts memory stabilization, which suggests the existence of a critical time window during which these processes are necessary. Using a computational model of kinase synthesis and…

  18. Design, Synthesis and Evaluation of 2,5-Diketopiperazines as Inhibitors of the MDM2-p53 Interaction.

    Directory of Open Access Journals (Sweden)

    Mariell Pettersson

    Full Text Available The transcription factor p53 is the main tumour suppressor in cells and many cancer types have p53 mutations resulting in a loss of its function. In tumours that retain wild-type p53 function, p53 activity is down-regulated by MDM2 (human murine double minute 2 via a direct protein-protein interaction. We have designed and synthesised two series of 2,5-diketopiperazines as inhibitors of the MDM2-p53 interaction. The first set was designed to directly mimic the α-helical region of the p53 peptide, containing key residues in the i, i+4 and i+7 positions of a natural α-helix. Conformational analysis indicated that 1,3,6-trisubstituted 2,5-diketopiperazines were able to place substituents in the same spatial orientation as an α-helix template. The key step of the synthesis involved the cyclisation of substituted dipeptides. The other set of tetrasubstituted 2,5-diketopiperazines were designed based on structure-based docking studies and the Ugi multicomponent reaction was used for the synthesis. This latter set comprised the most potent inhibitors which displayed micromolar IC50-values in a biochemical fluorescence polarisation assay.

  19. In Search of New Therapeutic Targets in Obesity Treatment: Sirtuins

    Directory of Open Access Journals (Sweden)

    Alina Kurylowicz

    2016-04-01

    Full Text Available Most of the available non-invasive medical therapies for obesity are non-efficient in a long-term evaluation; therefore there is a constant need for new methods of treatment. Research on calorie restriction has led to the discovery of sirtuins (silent information regulators, SIRTs, enzymes regulating different cellular pathways that may constitute potential targets in the treatment of obesity. This review paper presents the role of SIRTs in the regulation of glucose and lipid metabolism as well as in the differentiation of adipocytes. How disturbances of SIRTs’ expression and activity may lead to the development of obesity and related complications is discussed. A special emphasis is placed on polymorphisms in genes encoding SIRTs and their possible association with susceptibility to obesity and metabolic complications, as well as on data regarding altered expression of SIRTs in human obesity. Finally, the therapeutic potential of SIRTs-targeted strategies in the treatment of obesity and related disorders is discussed.

  20. A concise total synthesis of (R)-fluoxetine, a potent and selective serotonin reuptake inhibitor

    International Nuclear Information System (INIS)

    Fatima, Angelo de; Lapis, Alexandre Augusto M.; Pilli, Ronaldo A.

    2005-01-01

    (R)-Fluoxetine, potent and selective serotonin reuptake inhibitor, has been synthesized in six steps, 50% overall yield and 99% ee from benzaldehyde via catalytic asymmetric allylation with Maruoka's catalyst. (author)

  1. A concise total synthesis of (R)-fluoxetine, a potent and selective serotonin reuptake inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Fatima, Angelo de; Lapis, Alexandre Augusto M.; Pilli, Ronaldo A. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: pilli@iqm.unicamp.br

    2005-05-15

    (R)-Fluoxetine, potent and selective serotonin reuptake inhibitor, has been synthesized in six steps, 50% overall yield and 99% ee from benzaldehyde via catalytic asymmetric allylation with Maruoka's catalyst. (author)

  2. Seeking for Non-Zinc-Binding MMP-2 Inhibitors: Synthesis, Biological Evaluation and Molecular Modelling Studies

    Directory of Open Access Journals (Sweden)

    Alessandra Ammazzalorso

    2016-10-01

    Full Text Available Matrix metalloproteinases (MMPs are an important family of zinc-containing enzymes with a central role in many physiological and pathological processes. Although several MMP inhibitors have been synthesized over the years, none reached the market because of off-target effects, due to the presence of a zinc binding group in the inhibitor structure. To overcome this problem non-zinc-binding inhibitors (NZIs have been recently designed. In a previous article, a virtual screening campaign identified some hydroxynaphtyridine and hydroxyquinoline as MMP-2 non-zinc-binding inhibitors. In the present work, simplified analogues of previously-identified hits have been synthesized and tested in enzyme inhibition assays. Docking and molecular dynamics studies were carried out to rationalize the activity data.

  3. An efficient method for synthesis of succinate-based MMP inhibitors.

    Science.gov (United States)

    Sibi, Mukund P; Hasegawa, Hikaru

    2002-10-03

    A differentially protected fumarate undergoes radical addition followed by allylstannane trapping to provide disubstituted succinates in good yields and high anti diastereoselectivity. The conversion of the succinate to a known MMP inhibitor has been accomplished. [reaction: see text

  4. Design and synthesis of potent, orally-active DGAT-1 inhibitors containing a dioxino[2,3-d]pyrimidine core.

    Science.gov (United States)

    Dow, Robert L; Andrews, Melissa; Aspnes, Gary E; Balan, Gayatri; Michael Gibbs, E; Guzman-Perez, Angel; Karki, Kapil; Laperle, Jennifer L; Li, Jian-Cheng; Litchfield, John; Munchhof, Michael J; Perreault, Christian; Patel, Leena

    2011-10-15

    A novel series of potent DGAT-1 inhibitors was developed originating from the lactam-based clinical candidate PF-04620110. Incorporation of a dioxino[2,3-d]pyrimidine-based core afforded good alignment of pharmacophore features and resulted in improved passive permeability. Development of an efficient, homochiral synthesis of these targets facilitated confirmation of predictions regarding the stereochemical-dependence of DGAT-1 inhibition for this series. Compound 10 was shown to be a potent inhibitor of human DGAT-1 (10 nM) and to suppress triglyceride synthesis at oral doses of <3mg/kg. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Design and synthesis of aryl ether and sulfone hydroxamic acids as potent histone deacetylase (HDAC) inhibitors.

    Science.gov (United States)

    Pabba, Chittari; Gregg, Brian T; Kitchen, Douglas B; Chen, Zhen Jia; Judkins, Angela

    2011-01-01

    A series of novel hydroxamic acid based histone deacetylases (HDAC) inhibitors with aryl ether and aryl sulfone residues at the terminus of a substituted, unsaturated 5-carbon spacer moiety have been synthesized for the first time and evaluated. Compounds with meta- and para-substitution on the aryl ring of ether hydroxamic acids 19c, 20c, 19e, 19f and 19g are potent HDAC inhibitors with activities at low nanomolar levels. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Synthesis of gallinamide A analogues as potent falcipain inhibitors and antimalarials.

    Science.gov (United States)

    Conroy, Trent; Guo, Jin T; Elias, Nabiha; Cergol, Katie M; Gut, Jiri; Legac, Jennifer; Khatoon, Lubna; Liu, Yang; McGowan, Sheena; Rosenthal, Philip J; Hunt, Nicholas H; Payne, Richard J

    2014-12-26

    Analogues of the natural product gallinamide A were prepared to elucidate novel inhibitors of the falcipain cysteine proteases. Analogues exhibited potent inhibition of falcipain-2 (FP-2) and falcipain-3 (FP-3) and of the development of Plasmodium falciparum in vitro. Several compounds were equipotent to chloroquine as inhibitors of the 3D7 strain of P. falciparum and maintained potent activity against the chloroquine-resistant Dd2 parasite. These compounds serve as promising leads for the development of novel antimalarial agents.

  7. Synthesis and application of polyaminoamide as new paraffin inhibitor from vegetable oil

    OpenAIRE

    Chen, Gang; Tang, Ying; Zhang, Jie

    2011-01-01

    Abstract In this work, a series of novel paraffin inhibitor, polyaminoamide (PAA), was designed and prepared by aminolysis and poly-condensation using soybean oil and canola oil as the raw material. The property of the PAAs as paraffin inhibitor was investigated, the results show several PAA samples are potent in paraffin inhibition, and PPC-2 is the most effective one. Besides, the paraffin crystal morphology analysis was carried out to provide the mechanism of paraffin inhibition.

  8. Synthesis of the highly selective p38 MAPK inhibitor UR-13756 for possible therapeutic use in Werner syndrome.

    Science.gov (United States)

    Bagley, Mark C; Davis, Terence; Rokicki, Michal J; Widdowson, Caroline S; Kipling, David

    2010-02-01

    UR-13756 is a potent and selective p38 mitogen-activated protein kinase (MAPK) inhibitor, reported to have good bioavailability and pharmacokinetic properties and, thus, is of potential use in the treatment of accelerated aging in Werner syndrome. Irradiation of 2-chloroacrylonitrile and methylhydrazine in ethanol at 100 °C gives 1-methyl-3-aminopyrazole, which reacts with 4-fluorobenzaldehyde and a ketone, obtained by Claisen condensation of 4-picoline, in a Hantzsch-type 3-component hereocyclocondensation, to give the pyrazolopyridine UR-13756. UR-13756 shows p38 MAPK inhibitory activity in human telomerase reverse transcriptase-immortalized HCA2 dermal fibroblasts, with an IC(50) of 80 nm, as shown by ELISA, is 100% efficacious for up to 24 h at 1.0 μm and displays excellent kinase selectivity over the related stress-activated c-Jun kinases. In addition, UR-13756 is an effective p38 inhibitor at 1.0 μm in Werner syndrome cells, as shown by immunoblot. The convergent synthesis of UR-13756 is realized using microwave dielectric heating and provides a highly selective inhibitor that shows excellent selectivity for p38 MAPK over c-Jun N-terminal kinase.

  9. Nε-Acryloyllysine Piperazides as Irreversible Inhibitors of Transglutaminase 2: Synthesis, Structure-Activity Relationships, and Pharmacokinetic Profiling.

    Science.gov (United States)

    Wodtke, Robert; Hauser, Christoph; Ruiz-Gómez, Gloria; Jäckel, Elisabeth; Bauer, David; Lohse, Martin; Wong, Alan; Pufe, Johanna; Ludwig, Friedrich-Alexander; Fischer, Steffen; Hauser, Sandra; Greif, Dieter; Pisabarro, M Teresa; Pietzsch, Jens; Pietsch, Markus; Löser, Reik

    2018-05-24

    Transglutaminase 2 (TGase 2)-catalyzed transamidation represents an important post-translational mechanism for protein modification with implications in physiological and pathophysiological conditions, including fibrotic and neoplastic processes. Consequently, this enzyme is considered a promising target for the diagnosis of and therapy for these diseases. In this study, we report on the synthesis and kinetic characterization of N ε -acryloyllysine piperazides as irreversible inhibitors of TGase 2. Systematic structural modifications on 54 new compounds were performed with a major focus on fluorine-bearing substituents due to the potential of such compounds to serve as radiotracer candidates for positron emission tomography. The determined inhibitory activities ranged from 100 to 10 000 M -1 s -1 , which resulted in comprehensive structure-activity relationships. Structure-activity correlations using various substituent parameters accompanied by covalent docking studies provide an advanced understanding of the molecular recognition for this inhibitor class within the active site of TGase 2. Selectivity profiling of selected compounds for other transglutaminases demonstrated an excellent selectivity toward transglutaminase 2. Furthermore, an initial pharmacokinetic profiling of selected inhibitors was performed, including the assessment of potential membrane permeability and liver microsomal stability.

  10. Synthesis, conformational analysis, and biological activity of new analogues of thiazole-4-carboxamide adenine dinucleotide (TAD) as IMP dehydrogenase inhibitors.

    Science.gov (United States)

    Franchetti, Palmarisa; Cappellacci, Loredana; Pasqualini, Michela; Petrelli, Riccardo; Jayaprakasan, Vetrichelvan; Jayaram, Hiremagalur N; Boyd, Donald B; Jain, Manojkumar D; Grifantini, Mario

    2005-03-15

    Thiazole-4-carboxamide adenine dinucleotide (TAD) analogues T-2'-MeAD (1) and T-3'-MeAD (2) containing, respectively, a methyl group at the ribose 2'-C-, and 3'-C-position of the adenosine moiety, were prepared as potential selective human inosine monophosphate dehydrogenase (IMPDH) type II inhibitors. The synthesis of heterodinucleotides was carried out by CDI-catalyzed coupling reaction of unprotected 2'-C-methyl- or 3'-C-methyl-adenosine 5'-monophosphate with 2',3'-O-isopropylidene-tiazofurin 5'-monophosphate, and then deisopropylidenation. Biological evaluation of dinucleotides 1 and 2 as inhibitors of recombinant human IMPDH type I and type II resulted in a good activity. Inhibition of both isoenzymes by T-2'-MeAD and T-3'-MeAD was noncompetitive with respect to NAD substrate. Binding of T-3'-MeAD was comparable to that of parent compound TAD, while T-2'-MeAD proved to be a weaker inhibitor. However, no significant difference was found in inhibition of the IMPDH isoenzymes. T-2'-MeAD and T-3'-MeAD were found to inhibit the growth of K562 cells (IC(50) 30.7 and 65.0muM, respectively).

  11. Synthesis and characterisation of 5-acyl-6,7-dihydrothieno[3,2-c]pyridine inhibitors of Hedgehog acyltransferase

    Directory of Open Access Journals (Sweden)

    Thomas Lanyon-Hogg

    2016-06-01

    Full Text Available In this data article we describe synthetic and characterisation data for four members of the 5-acyl-6,7-dihydrothieno[3,2-c]pyridine (termed “RU-SKI” class of inhibitors of Hedgehog acyltransferase, including associated NMR spectra for final compounds. RU-SKI compounds were selected for synthesis based on their published high potencies against the enzyme target. RU-SKI 41 (9a, RU-SKI 43 (9b, RU-SKI 101 (9c, and RU-SKI 201 (9d were profiled for activity in the related article “Click chemistry armed enzyme linked immunosorbent assay to measure palmitoylation by Hedgehog acyltransferase” (Lanyon-Hogg et al., 2015 [1]. 1H NMR spectral data indicate different amide conformational ratios between the RU-SKI inhibitors, as has been observed in other 5-acyl-6,7-dihydrothieno[3,2-c]pyridines. The synthetic and characterisation data supplied in the current article provide validated access to the class of RU-SKI inhibitors.

  12. Metabolic control by sirtuins and other enzymes that sense NAD(+), NADH, or their ratio

    DEFF Research Database (Denmark)

    Anderson, Kristin A; Madsen, Andreas S; Olsen, Christian A

    2017-01-01

    NAD(+) is a dinucleotide cofactor with the potential to accept electrons in a variety of cellular reduction-oxidation (redox) reactions. In its reduced form, NADH is a ubiquitous cellular electron donor. NAD(+), NADH, and the NAD(+)/NADH ratio have long been known to control the activity of several...... oxidoreductase enzymes. More recently, enzymes outside those participating directly in redox control have been identified that sense these dinucleotides, including the sirtuin family of NAD(+)-dependent protein deacylases. In this review, we highlight examples of non-redox enzymes that are controlled by NAD......(+), NADH, or NAD(+)/NADH. In particular, we focus on the sirtuin family and assess the current evidence that the sirtuin enzymes sense these dinucleotides and discuss the biological conditions under which this might occur; we conclude that sirtuins sense NAD(+), but neither NADH nor the ratio. Finally, we...

  13. The life span-prolonging effect of sirtuin-1 is mediated by autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Maiuri, Maria Chiara; Markaki, Maria; Megalou, Evgenia; Pasparaki, Angela; Palikaras, Konstantinos; Criollo, Alfredo; Galluzzi, Lorenzo; Malik, Shoaib Ahmad; Vitale, Ilio; Michaud, Mickael; Madeo, Frank; Tavernarakis, Nektarios; Kroemer, Guido

    2010-01-01

    The life span of various model organisms can be extended by caloric restriction as well as by autophagy-inducing pharmacological agents. Life span-prolonging effects have also been observed in yeast cells, nematodes and flies upon the overexpression of the deacetylase Sirtuin-1. Intrigued by these observations and by the established link between caloric restriction and Sirtuin-1 activation, we decided to investigate the putative implication of Sirtuin-1 in the response of human cancer cells and Caenorhabditis elegans to multiple triggers of autophagy. Our data indicate that the activation of Sirtuin-1 (by the pharmacological agent resveratrol and/or genetic means) per se ignites autophagy, and that Sirtuin-1 is required for the autophagic response to nutrient deprivation, in both human and nematode cells, but not for autophagy triggered by downstream signals such as the inhibition of mTOR or p53. Since the life spanextending effects of Sirtuin-1 activators are lost in autophagy-deficient C. elegans, our results suggest that caloric restriction and resveratrol extend longevity, at least in experimental settings, by activating autophagy.

  14. Synthesis, pharmacological evaluation and molecular docking studies of pyrimidinedione based DPP-4 inhibitors as antidiabetic agents

    Science.gov (United States)

    Jha, Vibhu; Bhadoriya, Kamlendra Singh

    2018-04-01

    Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of newly developed antidiabetic drugs that bock DPP-4. DPP-4 is responsible for degradation of incretins harmones such as GLP-1 (Glucagon like Peptide) and GIP (Gastric inhibitory polypeptide) that maintain blood-glucose level. Pyrimidinedione based compounds were designed and synthesized for DPP-4 inhibitory activity. These heterocycles were designed by taking Alogliptin as a reference DPP-4 inhibitors and synthesized as N-methylated and N-benzylated pyrimidinediones. These compounds were subjected to DPP-4 assay, five out of nine synthesized compounds have shown in vitro DPP-4 inhibitory activity in significant range. Further, molecular docking studies of these compounds were performed on DPP-4 subunit and compared with natural DPP-4 inhibitors like Flavone, Resveratrol, Quercetin, Diprotin A. Docking studies have led to the conclusion that there are some identical amino acid interactions as Tyr 666 and Tyr 662, seen in both synthesized compounds and natural DPP-4 inhibitors. This study completely gives a good scope for further derivatisation and optimization of synthesized compounds to get clinical candidate as DPP-4 inhibitor for antidiabetic activity.

  15. Identification and development of novel indazole derivatives as potent bacterial peptidoglycan synthesis inhibitors

    Directory of Open Access Journals (Sweden)

    Prasanthi Malapati

    2018-01-01

    Full Text Available Background: Tuberculosis is well-known airborne disease caused by Mycobacterium tuberculosis. Available treatment regimen was unsuccessful in eradicating the deaths caused by the disease worldwide. Owing to the drawbacks such as prolonged treatment period, side effects, and drug tolerance, there resulted in patient noncompliance. In the current study, we attempted to develop inhibitors against unexplored key target glutamate racemase. Methods: Lead identification was done using thermal shift assay from in-house library; inhibitors were developed by lead derivatization technique and evaluated using various biological assays. Results: In indazole series, compounds 11 (6.32 ± 0.35 μM and 22 (6.11 ± 0.51 μM were found to be most promising potent inhibitors among all. These compounds also showed their inhibition on replicating and nonreplicating bacteria. Conclusion: We have developed the novel inhibitors against M. tuberculosis capable of inhibiting active and dormant bacteria, further optimization of inhibitor derivatives can results in better compounds for eradicating tuberculosis.

  16. BET Bromodomain Inhibitors with One-Step Synthesis Discovered from Virtual Screen.

    Science.gov (United States)

    Ayoub, Alex M; Hawk, Laura M L; Herzig, Ryan J; Jiang, Jiewei; Wisniewski, Andrea J; Gee, Clifford T; Zhao, Peiliang; Zhu, Jin-Yi; Berndt, Norbert; Offei-Addo, Nana K; Scott, Thomas G; Qi, Jun; Bradner, James E; Ward, Timothy R; Schönbrunn, Ernst; Georg, Gunda I; Pomerantz, William C K

    2017-06-22

    Chemical inhibition of epigenetic regulatory proteins BrdT and Brd4 is emerging as a promising therapeutic strategy in contraception, cancer, and heart disease. We report an easily synthesized dihydropyridopyrimidine pan-BET inhibitor scaffold, which was uncovered via a virtual screen followed by testing in a fluorescence anisotropy assay. Dihydropyridopyimidine 3 was subjected to further characterization and is highly selective for the BET family of bromodomains. Structure-activity relationship data and ligand deconstruction highlight the importance of the substitution of the uracil moiety for potency and selectivity. Compound 3 was also cocrystallized with Brd4 for determining the ligand binding pose and rationalizing subsequent structure-activity data. An additional series of dihydropyridopyrimidines was synthesized to exploit the proximity of a channel near the ZA loop of Brd4, leading to compounds with submicromolar affinity and cellular target engagement. Given these findings, novel and easily synthesized inhibitors are being introduced to the growing field of bromodomain inhibitor development.

  17. Molecular Design, Synthesis and Trypanocidal Activity of Dipeptidyl Nitriles as Cruzain Inhibitors

    Science.gov (United States)

    Avelar, Leandro A. A.; Camilo, Cristian D.; de Albuquerque, Sérgio; Fernandes, William B.; Gonçalez, Cristiana; Kenny, Peter W.; Leitão, Andrei; McKerrow, James H.; Montanari, Carlos A.; Orozco, Erika V. Meñaca; Ribeiro, Jean F. R.; Rocha, Josmar R.; Rosini, Fabiana; Saidel, Marta E.

    2015-01-01

    A series of compounds based on the dipeptidyl nitrile scaffold were synthesized and assayed for their inhibitory activity against the T. cruzi cysteine protease cruzain. Structure activity relationships (SARs) were established using three, eleven and twelve variations respectively at the P1, P2 and P3 positions. A K i value of 16 nM was observed for the most potent of these inhibitors which reflects a degree of non-additivity in the SAR. An X-ray crystal structure was determined for the ligand-protein complex for the structural prototype for the series. Twenty three inhibitors were also evaluated for their anti-trypanosomal effects and an EC50 value of 28 μM was observed for the most potent of these. Although there remains scope for further optimization, the knowledge gained from this study is also transferable to the design of cruzain inhibitors based on warheads other than nitrile as well as alternative scaffolds. PMID:26173110

  18. Design and synthesis of imidazopyridine analogues as inhibitors of phosphoinositide 3-kinase signaling and angiogenesis.

    Science.gov (United States)

    Kim, Okseon; Jeong, Yujeong; Lee, Hyunseung; Hong, Sun-Sun; Hong, Sungwoo

    2011-04-14

    Phosphatidylinositol 3-kinase α (PI3Kα) is an important regulator of intracellular signaling pathways, controlling remarkably diverse arrays of physiological processes. Because the PI3K pathway is frequently up-regulated in human cancers, the inhibition of PI3Kα can be a promising approach to cancer therapy. In this study, we have designed and synthesized a new series of imidazo[1,2-a]pyridine derivatives as PI3Kα inhibitors through the fragment-growing strategy. By varying groups at the 3- and 6-positions of imidazo[1,2-a]pyridines, we studied the structure-activity relationships (SAR) profiles and identified a series of potent PI3Kα inhibitors. Representative derivatives showed good activity in cellular proliferation and apoptosis assays. Moreover, these inhibitors exhibited noteworthy antiangiogenic activity.

  19. BET Bromodomain Inhibitors with One-Step Synthesis Discovered from Virtual Screen

    Energy Technology Data Exchange (ETDEWEB)

    Ayoub, Alex M.; Hawk, Laura M.L.; Herzig, Ryan J.; Jiang, Jiewei; Wisniewski, Andrea J.; Gee, Clifford T.; Zhao, Peiliang; Zhu, Jin-Yi; Berndt, Norbert; Offei-Addo, Nana K.; Scott, Thomas G.; Qi, Jun; Bradner, James E.; Ward, Timothy R.; Schönbrunn, Ernst; Georg, Gunda I.; Pomerantz, William C.K. (Moffitt); (UMM); (Harvard-Med)

    2017-06-06

    Chemical inhibition of epigenetic regulatory proteins BrdT and Brd4 is emerging as a promising therapeutic strategy in contraception, cancer, and heart disease. We report an easily synthesized dihydropyridopyrimidine pan-BET inhibitor scaffold, which was uncovered via a virtual screen followed by testing in a fluorescence anisotropy assay. Dihydropyridopyimidine 3 was subjected to further characterization and is highly selective for the BET family of bromodomains. Structure–activity relationship data and ligand deconstruction highlight the importance of the substitution of the uracil moiety for potency and selectivity. Compound 3 was also cocrystallized with Brd4 for determining the ligand binding pose and rationalizing subsequent structure–activity data. An additional series of dihydropyridopyrimidines was synthesized to exploit the proximity of a channel near the ZA loop of Brd4, leading to compounds with submicromolar affinity and cellular target engagement. Given these findings, novel and easily synthesized inhibitors are being introduced to the growing field of bromodomain inhibitor development.

  20. Synthesis and study of thiocarbonate derivatives of choline as potential inhibitors of acetylcholinesterase.

    Science.gov (United States)

    Boyle, N A; Talesa, V; Giovannini, E; Rosi, G; Norton, S J

    1997-09-12

    Fourteen alkyl and aryl thiocarbonate derivatives of choline were synthesized and studied as potential inhibitors of acetylcholinesterase (AChE). Twelve of the compounds inhibited AChEs derived from calf forebrain, human red blood cells, and octopus brain ranging from low to moderately high inhibition potency. The concentration of each inhibitory compound giving 50% inhibition of enzyme activity (IC50 values, which ranged from 1 x 10(-2) to 8 x 10(-7) M) was determined and is reported; inhibitor constants (Ki values) for the most inhibitory compounds, (1-pentylthiocarbonyl)choline chloride and (1-heptylthiocarbonyl)choline chloride, were calculated from kinetic data and are also reported. The inhibitors are competitive with substrate, and they are not hydrolyzed by the AChE activities. Certain of these new compounds may provide direction for the development of new drugs that have anticholinesterase activity and may be used for the treatment of Alzheimer's disease.

  1. HSP90 inhibitors potentiate PGF2α-induced IL-6 synthesis via p38 MAP kinase in osteoblasts.

    Directory of Open Access Journals (Sweden)

    Kazuhiko Fujita

    Full Text Available Heat shock protein 90 (HSP90 that is ubiquitously expressed in various tissues, is recognized to be a major molecular chaperone. We have previously reported that prostaglandin F2α (PGF2α, a potent bone remodeling mediator, stimulates the synthesis of interleukin-6 (IL-6 through p44/p42 mitogen-activated protein (MAP kinase and p38 MAP kinase in osteoblast-like MC3T3-E1 cells, and that Rho-kinase acts at a point upstream of p38 MAP kinase. In the present study, we investigated the involvement of HSP90 in the PGF2α-stimulated IL-6 synthesis and the underlying mechanism in MC3T3-E1 cells. Geldanamycin, an inhibitor of HSP90, significantly amplified both the PGF2α-stimulated IL-6 release and the mRNA expression levels. In addition, other HSP90 inhibitors, 17-allylamino-17demethoxy-geldanamycin (17-AAG and 17-dimethylamino-ethylamino-17-demethoxy-geldanamycin (17-DMAG and onalespib, enhanced the PGF2α-stimulated IL-6 release. Geldanamycin, 17-AAG and onalespib markedly strengthened the PGF2α-induced phosphorylation of p38 MAP kinase. Geldanamycin and 17-AAG did not affect the PGF2α-induced phosphorylation of p44/p42 MAP kinase and myosin phosphatase targeting subunit (MYPT-1, a substrate of Rho-kinase, and the protein levels of RhoA and Rho-kinase. In addition, HSP90-siRNA enhanced the PGF2α-induced phosphorylation of p38 MAP kinase. Furthermore, SB203580, an inhibitor of p38 MAP kinase, significantly suppressed the amplification by geldanamycin, 17-AAG or 17-DMAG of the PGF2α-stimulated IL-6 release. Our results strongly suggest that HSP90 negatively regulates the PGF2α-stimulated IL-6 synthesis in osteoblasts, and that the effect of HSP90 is exerted through regulating p38 MAP kinase activation.

  2. Design and synthesis of 3,3'-biscoumarin-based c-Met inhibitors.

    Science.gov (United States)

    Xu, Jimin; Ai, Jing; Liu, Sheng; Peng, Xia; Yu, Linqian; Geng, Meiyu; Nan, Fajun

    2014-06-14

    A library of biscoumarin-based c-Met inhibitors was synthesized, based on optimization of 3,3'-biscoumarin hit 3, which was identified as a non-ATP competitive inhibitor of c-Met from a diverse library of coumarin derivatives. Among these compounds, 38 and 40 not only showed potent enzyme activities with IC50 values of 107 nM and 30 nM, respectively, but also inhibited c-Met phosphorylation in BaF3/TPR-Met and EBC-1 cells.

  3. Synthesis and evaluation of a 5-Membered Isoiminosugar as Glycosidase Inhibitor

    DEFF Research Database (Denmark)

    Lundt, Inge; Godskesen, Michael Anders

    1998-01-01

    (3R, 4R)-4-hydroxy-3-hydroxymethylpyrrolidine (6) was prepared from D-xylose and found to be a weak inhibitor of alpha-D-, beta-D-glucosidase and alpha-L-fucosidase. (C) 1998 Published by Elsevier Science Ltd. All rights reserved....

  4. Design, synthesis and biological evaluation of uncharged catechol derivatives as selective inhibitors of PTP1B.

    Science.gov (United States)

    Li, Xiang-Qian; Xu, Qi; Luo, Jiao; Wang, Li-Jun; Jiang, Bo; Zhang, Ren-Shuai; Shi, Da-Yong

    2017-08-18

    Protein tyrosine phosphatases 1B (PTP1B) is a promising and validated therapeutic target to effectively treat T2DM and obesity. However, the development of charged PTP1B inhibitors was restricted due to their low cell permeability and poor bioavailability. Based on active natural products, two series of uncharged catechol derivatives were identified as PTP1B inhibitors by targeting a secondary aryl phosphate-binding site as well as the catalytic site. The most potent inhibitor 22 showed an IC 50 of 0.487 μM against PTP1B and strong selectivity (27-fold) over TCPTP. Kinetic studies were also performed that 22 act as a competitive PTP1B inhibitor. The treatment of C2C12 myotubes with 22 markedly increased the phosphorylation levels of IRβ, Akt and IRS1 phosphorylation. The similarity of its action profiling with that produced by insulin suggested its potential as a new non-insulin-dependent drug candidate. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Synthesis and Biological Evaluation of a Chitobiose-Based Peptide N-Glycanase Inhibitor Library

    NARCIS (Netherlands)

    Witte, Martin D.; Horst, Danielle; Wiertz, Emmanuel J.H.J.; Marel, Gijsbert A. van der; Overkleeft, Herman S.

    2009-01-01

    Peptide N-glycanase (PNGase), the enzyme responsible for the deglycosylation of N-linked glycoproteins, has an active site related to that of cysteine proteases. Chitiobiose was equipped with electrophilic traps often used in cysteine protease inhibitors, and the resulting compounds were evaluated

  6. Design and synthesis of macrocyclic peptidyl hydroxamates as peptide deformylase inhibitors.

    Science.gov (United States)

    Shen, Gang; Zhu, Jinge; Simpson, Anthony M; Pei, Dehua

    2008-05-15

    Macrocyclic peptidyl hydroxamates were designed, synthesized, and evaluated as peptide deformylase (PDF) inhibitors. The most potent compound exhibited tight, slow-binding inhibition of Escherichia coli PDF (K(I)(*)=4.4 nM) and had potent antibacterial activity against Gram-positive bacterium Bacillus subtilis (MIC=2-4 microg/mL).

  7. Synthesis and biological evaluation of lycorine derivatives as dual inhibitors of human acetylcholinesterase and butyrylcholinesterase

    Directory of Open Access Journals (Sweden)

    Wang Yue-Hu

    2012-09-01

    Full Text Available Abstract Background Alzheimer’s disease (AD is a neurologically degenerative disorder that affects more than 20 million people worldwide. The selective butyrylcholinesterase (BChE inhibitors and bivalent cholinesterase (ChE inhibitors represent new treatments for AD. Findings A series of lycorine derivatives (1–10 were synthesized and evaluated for anti-cholinesterase activity. Result showed that the novel compound 2-O-tert-butyldimethylsilyl-1-O-(methylthiomethyllycorine (7 was a dual inhibitor of human acetylcholinesterase (hAChE and butyrylcholinesterase (hBChE with IC50 values of 11.40 ± 0.66 μM and 4.17 ± 0.29 μM, respectively. The structure-activity relationships indicated that (i the 1-O-(methylthiomethyl substituent in lycorine was better than the 1-O-acetyl group for the inhibition of cholinesterase; (ii the acylated or etherified derivatives of lycorine and lycorin-2-one were more potent against hBChE than hAChE; and (iii the oxidation of lycorine at C-2 decreases the activity. Conclusion Acylated or etherified derivatives of lycorine are potential dual inhibitors of hBChE and hAChE. Hence, further study on the modification of lycorine for ChE inhibition is necessary.

  8. Design, Synthesis, and Herbicidal Activity of Pyrimidine-Biphenyl Hybrids as Novel Acetohydroxyacid Synthase Inhibitors.

    Science.gov (United States)

    Li, Ke-Jian; Qu, Ren-Yu; Liu, Yu-Chao; Yang, Jing-Fang; Devendar, Ponnam; Chen, Qiong; Niu, Cong-Wei; Xi, Zhen; Yang, Guang-Fu

    2018-04-18

    The issue of weed resistance to acetohydroxyacid synthase (EC 2.2.1.6, AHAS) inhibitors has become one of the largest obstacles for the application of this class of herbicides. In a continuing effort to discover novel AHAS inhibitors to overcome weed resistance, a series of pyrimidine-biphenyl hybrids (4aa-bb and 5aa-ah) were designed and synthesized via a scaffold hopping strategy. Among these derivatives, compounds 4aa ( K i = 0.09 μM) and 4bb ( K i = 0.02 μM) displayed higher inhibitory activities against Arabidopsis thaliana AHAS than those of the controls bispyribac ( K i = 0.54 μM) and flumetsulam ( K i = 0.38 μM). Remarkably, compounds 4aa, 4bb, 5ah, and 5ag exhibited excellent postemergence herbicidal activity and a broad spectrum of weed control at application rates of 37.5-150 g of active ingredient (ai)/ha. Furthermore, 4aa and 4bb showed higher herbicidal activity against AHAS inhibitor-resistant Descurainia sophia, Ammannia arenaria, and the corresponding sensitive weeds than that of bispyribac at 0.94-0.235 g ai/ha. Therefore, the pyrimidine-biphenyl motif and lead compounds 4aa and 4bb have great potential for the discovery of novel AHAS inhibitors to combat AHAS-inhibiting herbicide-resistant weeds.

  9. A short synthesis and its application to the preparation of radio labelled leukotriene inhibitor Sch 37224

    International Nuclear Information System (INIS)

    Duelfer, T.; Gala, D.

    1991-01-01

    A new, short synthesis of 1-(1,2-dihydro-4-hydroxyl-1-phenyl-2-oxo-1,8-naphthyridin-3-yl)-pyrrolidinium hydroxide, inner salt, 1, was achieved by condensing methyl 2-phenylamino-3-pyridine carboxylate 2 with ethyl 1-pyrrolidine acetate 4. This gave highly pure product in 60% yield. This synthesis was applied to the preparation of 14 C labelled 1. Radiolabelled 1 was synthesized from u-[ 14 C]-aniline in three steps at 97% radiochemical purity and 27.3% radiochemical yield. (author)

  10. Histone deacetylase inhibitors for the treatment of cancer stem cells

    Czech Academy of Sciences Publication Activity Database

    Dvořáková, Marcela; Vaněk, Tomáš

    2016-01-01

    Roč. 7, č. 12 (2016), s. 2217-2231 ISSN 2040-2503 R&D Projects: GA MŠk LD14128 Institutional support: RVO:61389030 Keywords : acute myeloid-leukemia * epithelial-mesenchymal transition * acute myelogenous leukemia * tumor-initiating cells * human aml cells * breast-cancer * hdac inhibitors * sirtuin inhibitors * colorectal-cancer * anticancer agents Subject RIV: CC - Organic Chemistry Impact factor: 2.608, year: 2016

  11. Human keratinocytes produce the complement inhibitor factor H: synthesis is regulated by interferon-gamma

    NARCIS (Netherlands)

    Timár, Krisztina K.; Pasch, Marcel C.; van den Bosch, Norbert H. A.; Jarva, Hanna; Junnikkala, Sami; Meri, Seppo; Bos, Jan D.; Asghar, Syed S.

    2006-01-01

    Locally synthesized complement is believed to play an important role in host defense and inflammation at organ level. In the epidermis, keratinocytes have so far been shown to synthesize two complement components, C3 and factor B. Here, we studied the synthesis of factor H by human keratinocytes. We

  12. Design, Synthesis, and Evaluation of Dihydrobenzo[cd]indole-6-sulfonamide as TNF-alpha Inhibitors

    Science.gov (United States)

    Deng, Xiaobing; Zhang, Xiaoling; Tang, Bo; Liu, Hongbo; Shen, Qi; Liu, Ying; Lai, Luhua

    2018-04-01

    Tumor necrosis factor-α (TNF-α) plays a pivotal role in inflammatory response. Dysregulation of TNF can lead to a variety of disastrous pathological effects, including auto-inflammatory diseases. Antibodies that directly targeting TNF-α have been proven effective in suppressing symptoms of these disorders. Compared to protein drugs, small molecule drugs are normally orally available and less expensive. Till now, peptide and small molecule TNF-α inhibitors are still in the early stage of development, and much more efforts should be made. In a previously study, we reported a TNF-α inhibitor, EJMC-1 with modest activity. Here, we optimized this compound by shape screen and rational design. In the first round, we screened commercial compound library for EJMC-1 analogs based on shape similarity. Out of the 68 compounds tested, 20 compounds showed better binding affinity than EJMC-1 in the SPR competitive binding assay. These 20 compounds were tested in cell assay and the most potent compound was 2-oxo-N-phenyl-1,2-dihydrobenzo[cd]indole-6-sulfonamide (S10) with an IC50 of 14 M, which was 2.2-fold stronger than EJMC-1. Based on the docking analysis of S10 and EJMC-1 binding with TNF-α, in the second round, we designed S10 analogues, purchased 7 of them and synthesized 7 new compounds. The best compound, 4e showed an IC50 value of 3 M in cell assay, which was 14-fold stronger than EJMC-1. 4e was among the most potent TNF-α organic compound inhibitors reported so far. Our study demonstrated that 2-oxo-N-phenyl-1,2-dihydrobenzo[cd]indole-6-sulfonamide analogues could be developed as potent TNF-α inhibitors. 4e can be further optimized for its activity and properties. Our study provides insights into designing small molecule inhibitors directly targeting TNF-α and for protein-protein interaction inhibitor design.

  13. Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues

    Directory of Open Access Journals (Sweden)

    Xu-Wen Li

    2013-07-01

    Full Text Available Aurachins are myxobacterial 3-farnesyl-4(1H-quinolone derived compounds initially described as respiratory chain inhibitors, more specifically as inhibitors of various cytochrome complexes. They are also known as potent antibiotic compounds. We describe herein the first synthesis of aurachin D through a key Conrad–Limpach reaction. The same strategy was used to reach some ring as opposed to chain analogues, allowing for the description of structure–activity relationships. Biological screening of the analogues showed antiparasitic, cytotoxic, antibacterial and antifungal activities, and depletion of the mitochondrial membrane potential. The strongest activity was found on Plasmodium falciparum with a selectivity index of 345, compared to Vero cells, for the natural product and its geranyl analogue. The loss of mitochondrial membrane potential induced by aurachins in human U-2 OS osteosarcoma cells was studied, showing the best activity for aurachin D and a naphthalene analogue, yet without totally explaining the observed cytotoxic activity of the compounds. Finally, a synthetic entry is given to the complete carboheterocyclic core of aurachin H through the N-oxidation/epoxidation of aurachin D and a shorter chain analogue, followed by subsequent biomimetic cyclization.

  14. Synthesis of natural urolithin M6, a galloflavin mimetic, as a potential inhibitor of lactate dehydrogenase A.

    Science.gov (United States)

    Rupiani, Sebastiano; Guidotti, Laura; Manerba, Marcella; Di Ianni, Lorenza; Giacomini, Elisa; Falchi, Federico; Di Stefano, Giuseppina; Roberti, Marinella; Recanatini, Maurizio

    2016-11-22

    Glycolysis is the main route for energy production in tumors. LDH-A is a key enzyme of this process and its inhibition represents an attractive strategy to hamper cancer cell metabolism. Galloflavin is a reliable LDH-A inhibitor as previously identified by us; however, its poor physicochemical properties and chemical tractability render it unsuitable for further development. Therefore, a rational design was undertaken with the aim to reproduce the pharmacophore of galloflavin on simpler, potentially more soluble and synthetic accessible scaffolds. Following a process of structural simplification, natural urolithin M6 (UM6), which is an ellagitannin metabolite produced by gut microbiota, was identified as a putative galloflavin mimetic. In the present study, the synthesis of UM6 is described for the first time. An efficient synthetic pathway has been developed, which involved five steps from readily accessible starting materials. The key reaction steps, a Suzuki coupling and an intramolecular C-H oxygenation, have been optimized to improve the synthetic feasibility and provide the best conditions in terms of reaction time and yield. Moreover, this route would be suitable to obtain other analogs for SAR studies. Preliminary biological tests revealed that UM6 was able to smoothly reproduce the behavior of galloflavin, confirming that our approach was successful in providing a new and accessible structure in the search for new LDH-A inhibitors.

  15. Gram-scale synthesis of the p38α MAPK-inhibitor VX-745 for preclinical studies into Werner syndrome.

    Science.gov (United States)

    Bagley, Mark C; Davis, Terence; Dix, Matthew C; Fusillo, Vincenzo; Pigeaux, Morgane; Rokicki, Michal J; Kipling, David

    2010-09-01

    The ATP-competitive p38α MAPK inhibitor VX-745 exhibits an exquisite kinase selectivity profile, is effective in blocking p38 stress signaling in Werner syndrome dermal fibroblasts, has efficacy in clinical trials and may have therapeutic value against Werner syndrome. Previous synthetic routes, however, have only resulted in milligram quantities suitable for cell-based studies, whereas gram quantities would be required for in vivo use. Microwave irradiation using a stop-flow monomodal microwave reactor has been found to facilitate scale-up of the synthesis of VX-745. Ullmann-type C-S bond formation using thiophenol, chloropyridazine, copper(I) catalyst and diol ligand proceeds rapidly and efficiently in this apparatus for elaboration to the pyrimido[1,6-b]pyridazinone core of VX-745 on gram scale and with good overall yield. This method delivers the p38 inhibitor VX-745 in sufficient quantities for preclinical studies to rescue the aging phenotype in Werner syndrome.

  16. A novel selective prostaglandin E2 synthesis inhibitor relieves pyrexia and arthritis in Guinea pigs inflammatory models

    Directory of Open Access Journals (Sweden)

    Ryusuke Sugita

    2016-02-01

    Full Text Available Prostaglandin E2 (PGE2, one of the terminal products in the cyclooxygenase pathway, plays an important role in various inflammatory responses. To determine whether selective inhibition of PGE2 may relieve these inflammatory symptoms, we synthesized a selective PGE2 synthesis inhibitor, compound A [1-(6-fluoro-5,7-dimethyl-1,3-benzothiazol-2-yl-N-[(1S,2R-2-(hydroxymethylcyclohexyl]piperidine-4-carboxamide], then investigated the effects on pyrexia, arthritis and inflammatory pain in guinea pigs. In LPS-stimulated guinea pig macrophages, compound A selectively inhibited inducible PGE2 biosynthesis in a dose-dependent manner whereas enhanced the formation of thromboxane B2 (TXB2. Compound A suppressed yeast-evoked PGE2 production selectively and enhanced the production of TXB2 and 6-keto PGF1α in vivo. In addition, compound A relieved yeast-induced pyrexia and also suppressed paw swelling in an adjuvant-induced arthritis model. The effect on gastrointestinal (GI ulcer formation was also evaluated and compound A showed a lower GI adverse effect than indomethacin. However, compound A failed to relieve yeast-induced thermal hyperalgesia. These results suggest that selective inhibition of PGE2 synthesis may have anti-pyretic and anti-inflammatory properties without GI side effect, but lack the analgesic efficacy.

  17. 3-Arylpropionylhydroxamic acid derivatives as Helicobacter pylori urease inhibitors: Synthesis, molecular docking and biological evaluation.

    Science.gov (United States)

    Shi, Wei-Kang; Deng, Rui-Cheng; Wang, Peng-Fei; Yue, Qin-Qin; Liu, Qi; Ding, Kun-Ling; Yang, Mei-Hui; Zhang, Hong-Yu; Gong, Si-Hua; Deng, Min; Liu, Wen-Run; Feng, Qiu-Ju; Xiao, Zhu-Ping; Zhu, Hai-Liang

    2016-10-01

    Helicobacter pylori urease is involved in several physiologic responses such as stomach and duodenal ulcers, adenocarcinomas and stomach lymphomas. Thus, inhibition of urease is taken for a good chance to treat H. pylori-caused infections, we have therefore focused our efforts on seeking novel urease inhibitors. Here, a series of arylpropionylhydroxamic acids were synthesized and evaluated for urease inhibition. Out of these compounds, 3-(2-benzyloxy-5-chlorophenyl)-3-hydroxypropionylhydroxamic acid (d24) was the most active inhibitor with IC50 of 0.15±0.05μM, showing a mixed inhibition with both competitive and uncompetitive aspects. Non-linear fitting of kinetic data gives kinetics parameters of 0.13 and 0.12μg·mL(-1) for Ki and Ki', respectively. The plasma protein binding assays suggested that d24 exhibited moderate binding to human and rabbit plasma proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Bisindolylmethane thiosemicarbazides as potential inhibitors of urease: Synthesis and molecular modeling studies.

    Science.gov (United States)

    Taha, Muhammad; Ullah, Hayat; Al Muqarrabun, Laode Muhammad Ramadhan; Khan, Muhammad Naseem; Rahim, Fazal; Ahmat, Norizan; Javid, Muhammad Tariq; Ali, Muhammad; Khan, Khalid Mohammed

    2018-01-01

    Bisindolylmethane thiosemicarbazides 1-18 were synthesized, characterized by 1 H NMR and ESI MS and evaluated for urease inhibitory potential. All analogs showed outstanding urease inhibitory potentials with IC 50 values ranging between 0.14 ± 0.01 to 18.50 ± 0.90 μM when compared with the standard inhibitor thiourea having IC 50 value 21.25 ± 0.90 μM. Among the series, analog 9 (0.14 ± 0.01 μM) with di-chloro substitution on phenyl ring was identified as the most potent inhibitor of urease. The structure activity relationship has been also established on the basis of binding interactions of the active analogs. These binding interactions were identified by molecular docking studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Synthesis, Biological Evaluation and Molecular Modelling of 2′-Hydroxychalcones as Acetylcholinesterase Inhibitors

    Directory of Open Access Journals (Sweden)

    Sri Devi Sukumaran

    2016-07-01

    Full Text Available A series of 2′-hydroxy- and 2′-hydroxy-4′,6′-dimethoxychalcones was synthesised and evaluated as inhibitors of human acetylcholinesterase (AChE. The majority of the compounds were found to show some activity, with the most active compounds having IC50 values of 40–85 µM. Higher activities were generally observed for compounds with methoxy substituents in the A ring and halogen substituents in the B ring. Kinetic studies on the most active compounds showed that they act as mixed-type inhibitors, in agreement with the results of molecular modelling studies, which suggested that they interact with residues in the peripheral anionic site and the gorge region of AChE.

  20. Synthesis and biological evaluation of novel bis-aromatic amides as novel PTP1B inhibitors.

    Science.gov (United States)

    Wang, Wen-Long; Huang, Chao; Gao, Li-Xin; Tang, Chun-Lan; Wang, Jun-Qing; Wu, Min-Chen; Sheng, Li; Chen, Hai-Jun; Nan, Fa-Jun; Li, Jing-Ya; Li, Jia; Feng, Bainian

    2014-04-15

    A series of bis-aromatic amides was designed, synthesized, and evaluated as a new class of inhibitors with IC50 values in the micromolar range against protein tyrosine phosphatase 1B (PTP1B). Among them, compound 15 displayed an IC50 value of 2.34±0.08 μM with 5-fold preference over TCPTP. More importantly, the treatment of CHO/HIR cells with compound 15 resulted in increased phosphorylation of insulin receptor (IR), which suggested extensive cellular activity of compound 15. These results provided novel lead compounds for the design of inhibitors of PTP1B as well as other PTPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Design and synthesis of novel chalcones as potent selective monoamine oxidase-B inhibitors.

    Science.gov (United States)

    Hammuda, Arwa; Shalaby, Raed; Rovida, Stefano; Edmondson, Dale E; Binda, Claudia; Khalil, Ashraf

    2016-05-23

    A novel series of substituted chalcones were designed and synthesized to be evaluated as selective human MAO-B inhibitors. A combination of either methylsulfonyl or trifluoromethyl substituents on the aromatic ketone moiety with a benzodioxol ring on the other end of the chalcone scaffold was investigated. The compounds were tested for their inhibitory activities on both human MAO-A and B. All compounds appeared to be selective MAO-B inhibitors with Ki values in the micromolar to submicromolar range. Molecular modeling studies have been performed to get insight into the binding mode of the synthesized compounds to human MAO-B active site. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. Synthesis, QSAR, and Molecular Dynamics Simulation of Amidino-substituted Benzimidazoles as Dipeptidyl Peptidase III Inhibitors.

    Science.gov (United States)

    Rastija, Vesna; Agić, Dejan; Tomiš, Sanja; Nikolič, Sonja; Hranjec, Marijana; Grace, Karminski-Zamola; Abramić, Marija

    2015-01-01

    A molecular modeling study is performed on series of benzimidazol-based inhibitors of human dipeptidyl peptidase III (DPP III). An eight novel compounds were synthesized in excellent yields using green chemistry approach. This study is aimed to elucidate the structural features of benzimidazole derivatives required for antagonism of human DPP III activity using Quantitative Structure-Activity Relationship (QSAR) analysis, and to understand the mechanism of one of the most potent inhibitor binding into the active site of this enzyme, by molecular dynamics (MD) simulations. The best model obtained includes S3K and RDF045m descriptors which have explained 89.4 % of inhibitory activity. Depicted moiety for strong inhibition activity matches to the structure of most potent compound. MD simulation has revealed importance of imidazolinyl and phenyl groups in the mechanism of binding into the active site of human DPP III.

  3. Piperazine sulfonamide BACE1 inhibitors: Design, synthesis, and in vivo characterization

    Energy Technology Data Exchange (ETDEWEB)

    Cumming, Jared; Babu, Suresh; Huang, Ying; Carrol, Carolyn; Chen, Xia; Favreau, Leonard; Greenlee, William; Guo, Tao; Kennedy, Matthew; Kuvelkar, Reshma; Le, Thuy; Li, Guoqing; McHugh, Nansie; Orth, Peter; Ozgur, Lynne; Parker, Eric; Saionz, Kurt; Stamford, Andrew; Strickland, Corey; Tadesse, Dawit; Voigta, Johannes; Zhang, Lili; Zhang, Qi (Ligand); (Merck)

    2010-08-17

    With collaboration between chemistry, X-ray crystallography, and molecular modeling, we designed and synthesized a series of novel piperazine sulfonamide BACE1 inhibitors. Iterative exploration of the non-prime side and S2{prime} sub-pocket of the enzyme culminated in identification of an analog that potently lowers peripheral A{beta}{sub 40} in transgenic mice with a single subcutaneous dose.

  4. Synthesis and preliminary biological evaluation of new radioiodinated MMP inhibitors for imaging MMP activity in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Kopka, Klaus E-mail: kopka@uni-muenster.de; Breyholz, Hans-Joerg; Wagner, Stefan; Law, Marilyn P.; Riemann, Burkhard; Schroeer, Sandra; Trub, Monika; Guilbert, Benedicte; Levkau, Bodo; Schober, Otmar; Schaefers, Michael

    2004-02-01

    Non-invasive measurement of matrix metalloproteinase (MMP) activity in vivo is a clinical challenge in many disease processes such as inflammation, tumor metastasis and atherosclerosis. Therefore, radioiodinated analogues of the non-peptidyl broad-spectrum MMP inhibitor (MMPI) CGS 27023A 1a were synthesized for non-invasive detection of MMP activity in vivo using single photon emission computed tomography (SPECT). The compounds Br-CGS 27023A 1b and HO-CGS 27023A 1d were synthesized from the amino acid D-valine and used as precursors for radioiodinated derivatives of CGS 27023A and their non-radioactive references I-CGS 27023A 1c and HO-I-CGS 27023A 1e. Radioiodination of the precursors with [{sup 123}I]NaI or [{sup 125}I]NaI produced the no-carrier-added MMP inhibitors [{sup 123}I]I-CGS 27023A 1f, [{sup 125}I]I-CGS 27023A 1g, HO-[{sup 123}I]I-CGS27023A 1h, and HO-[{sup 125}I]I-CGS 27023A 1i. In vitro studies showed that the non-radioactive analogues of the MMP inhibitors exhibited affinities against gelatinase A (MMP-2) and gelatinase B (MMP-9) in the nanomolar range, comparable to the parent compound CGS 27023A. In vivo biodistribution using HO-[{sup 125}I]I-CGS 27023A 1i in CL57 Bl6 mice showed rapid blood and plasma clearance and low retention in normal tissues. The preliminary biological evaluation warrant further studies of these radioiodinated MMP inhibitors as potential new radiotracers for imaging MMP activity in vivo.

  5. Synthesis and preliminary biological evaluation of new radioiodinated MMP inhibitors for imaging MMP activity in vivo

    International Nuclear Information System (INIS)

    Kopka, Klaus; Breyholz, Hans-Joerg; Wagner, Stefan; Law, Marilyn P.; Riemann, Burkhard; Schroeer, Sandra; Trub, Monika; Guilbert, Benedicte; Levkau, Bodo; Schober, Otmar; Schaefers, Michael

    2004-01-01

    Non-invasive measurement of matrix metalloproteinase (MMP) activity in vivo is a clinical challenge in many disease processes such as inflammation, tumor metastasis and atherosclerosis. Therefore, radioiodinated analogues of the non-peptidyl broad-spectrum MMP inhibitor (MMPI) CGS 27023A 1a were synthesized for non-invasive detection of MMP activity in vivo using single photon emission computed tomography (SPECT). The compounds Br-CGS 27023A 1b and HO-CGS 27023A 1d were synthesized from the amino acid D-valine and used as precursors for radioiodinated derivatives of CGS 27023A and their non-radioactive references I-CGS 27023A 1c and HO-I-CGS 27023A 1e. Radioiodination of the precursors with [ 123 I]NaI or [ 125 I]NaI produced the no-carrier-added MMP inhibitors [ 123 I]I-CGS 27023A 1f, [ 125 I]I-CGS 27023A 1g, HO-[ 123 I]I-CGS27023A 1h, and HO-[ 125 I]I-CGS 27023A 1i. In vitro studies showed that the non-radioactive analogues of the MMP inhibitors exhibited affinities against gelatinase A (MMP-2) and gelatinase B (MMP-9) in the nanomolar range, comparable to the parent compound CGS 27023A. In vivo biodistribution using HO-[ 125 I]I-CGS 27023A 1i in CL57 Bl6 mice showed rapid blood and plasma clearance and low retention in normal tissues. The preliminary biological evaluation warrant further studies of these radioiodinated MMP inhibitors as potential new radiotracers for imaging MMP activity in vivo

  6. The design and synthesis of novel spirocyclic heterocyclic sulfone ROMK inhibitors as diuretics.

    Science.gov (United States)

    Chobanian, Harry R; Guo, Yan; Pio, Barbara; Tang, Haifeng; Teumelsan, Nardos; Clements, Matthew; Frie, Jessica; Ferguson, Ronald; Guo, Zach; Thomas-Fowlkes, Brande S; Felix, John P; Liu, Jessica; Kohler, Martin; Priest, Birgit; Hampton, Caryn; Pai, Lee-Yuh; Corona, Aaron; Metzger, Joseph; Tong, Vincent; Joshi, Elizabeth M; Xu, Ling; Owens, Karen; Maloney, Kevin; Sullivan, Kathleen; Pasternak, Alexander

    2017-02-15

    A spirocyclic class of ROMK inhibitors was developed containing a structurally diverse heterocyclic sulfone moiety and spirocyclic core starting from lead 1. These compounds not only displayed exquisite ROMK potency but significantly improved selectivity over hERG. The lead compounds were found to have favorable pharmacokinetic properties and displayed robust diuretic, natriuretic and blood pressure lowering effects in spontaneously hypertensive rats. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Synthesis and in vitro Evaluation of 2-heteroarylidene-1-tetralone Derivatives as Monoamine Oxidase Inhibitors.

    Science.gov (United States)

    Amakali, Klaudia T; Legoabe, Lesetja J; Petzer, Anél; Petzer, Jacobus P

    2018-05-14

    The present study investigates the human monoamine oxidase (MAO) inhibition properties of a series of twelve 2-heteroarylidene-1-tetralone derivatives. Also included are related cyclohexylmethylidene, cyclopentylmethylidene and benzylidene substituted 1-tetralones. These compounds are related to the 2-benzylidene-1-indanone class of compounds which has previously been shown to inhibit the MAOs, with specificity for the MAO-B isoform. The target compounds were synthesised by the Claisen-Schmidt condensation between 7-methoxy-1-tetralone or 1-tetralone, and various aldehydes, under acid (hydrochloric acid) or base (potassium hydroxide) catalysis. The results of the MAO inhibition studies showed that the 2-heteroarylidene-1-tetralone and related derivatives are in most instances more selective inhibitors of the MAO-B isoform compared to MAO-A. (2E)-2-Benzylidene-7-methoxy-3,4-dihydronaphthalen-1(2 H)-one (IC 50 =0.707 μM) was found to be the most potent MAO-B inhibitor, while the most potent MAO-A inhibitor was (2E)-2-[(2-chloropyridin-3-yl)methylidene]-7-methoxy-3,4-dihydronaphthalen-1(2 H)-one (IC 50 =1.37 μM). The effect of the heteroaromatic substituent on MAO-B inhibition activity, in decreasing order was found to be: cyclohexyl, phenyl>thiophene>pyridine, furane, pyrrole, cyclopentyl. This study concludes that, although some 2-heteroarylidene-1-tetralone derivatives are good potency MAO inhibitors, in general their inhibition potencies, particularly for MAO-B, are lower than structurally related chalcones and 1-indanone derivatives that were previously studied. © Georg Thieme Verlag KG Stuttgart · New York.

  8. Synthesis and Pharmacological Evaluation of Selective Histone Deacetylase 6 Inhibitors in Melanoma Models

    Czech Academy of Sciences Publication Activity Database

    Tavares, M. T.; Shen, S.; Knox, T.; Hadley, M.; Kutil, Zsofia; Bařinka, Cyril; Villagra, A.; Kozikowski, A. P.

    2017-01-01

    Roč. 8, č. 10 (2017), s. 1031-1036 ISSN 1948-5875 R&D Projects: GA ČR GA15-19640S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : HDAC6 inhibitors * nexturastat A * melanoma Subject RIV: FR - Pharmacology ; Medidal Chemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 3.746, year: 2016

  9. Synthesis and Evaluation of the Tumor Cell Growth Inhibitory Potential of New Putative HSP90 Inhibitors.

    Science.gov (United States)

    Bizarro, Ana; Sousa, Diana; Lima, Raquel T; Musso, Loana; Cincinelli, Raffaella; Zuco, Vantina; De Cesare, Michelandrea; Dallavalle, Sabrina; Vasconcelos, M Helena

    2018-02-13

    Heat shock protein 90 (HSP90) is a well-known target for cancer therapy. In a previous work, some of us have reported a series of 3-aryl-naphtho[2,3- d ]isoxazole-4,9-diones as inhibitors of HSP90. In the present work, various compounds with new chromenopyridinone and thiochromenopyridinone scaffolds were synthesized as potential HSP90 inhibitors. Their binding affinity to HSP90 was studied in vitro. Selected compounds ( 5 and 8 ) were further studied in various tumor cell lines regarding their potential to cause cell growth inhibition, alter the cell cycle profile, inhibit proliferation, and induce apoptosis. Their effect on HSP90 client protein levels was also confirmed in two cell lines. Finally, the antitumor activity of compound 8 was studied in A431 squamous cell carcinoma xenografts in nude mice. Our results indicated that treatment with compounds 5 and 8 decreased the proliferation of tumor cell lines and compound 8 induced apoptosis. In addition, these two compounds were able to downregulate selected proteins known as "clients" of HSP90. Finally, treatment of xenografted mice with compound 5 resulted in a considerable dose-dependent inhibition of tumor growth. Our results show that two new compounds with a chromenopyridinone and thiochromenopyridinone scaffold are promising putative HSP90 inhibitors causing tumor cell growth inhibition.

  10. How polyamine synthesis inhibitors and cinnamic acid affect tropane alkaloid production.

    Science.gov (United States)

    Marconi, Patricia L; Alvarez, María A; Pitta-Alvarez, Sandra I

    2007-01-01

    Hairy roots of Brugmansia candida produce the tropane alkaloids scopolamine and hyoscyamine. In an attempt to divert the carbon flux from competing pathways and thus enhance productivity, the polyamine biosynthesis inhibitors cyclohexylamine (CHA) and methylglyoxal-bis-guanylhydrazone (MGBG) and the phenylalanine-ammonia-lyase inhibitor cinnamic acid were used. CHA decreased the specific productivity of both alkaloids but increased significantly the release of scopolamine (approx 500%) when it was added in the mid-exponential phase. However, when CHA was added for only 48 h during the exponential phase, the specific productivity of both alkaloids increased (approx 200%), favoring scopolamine. Treatment with MGBG was detrimental to growth but promoted release into the medium of both alkaloids. However, when it was added for 48 h during the exponential phase, MGBG increased the specific productivity (approx 200%) and release (250- 1800%) of both alkaloids. Cinnamic acid alone also favored release but not specific productivity. When a combination of CHA or MGBG with cinnamic acid was used, the results obtained were approximately the same as with each polyamine biosynthesis inhibitor alone, although to a lesser extent. Regarding root morphology, CHA inhibited growth of primary roots and ramification. However, it had a positive effect on elongation of lateral roots.

  11. Synthesis, biological evaluation and molecular docking of N-phenyl thiosemicarbazones as urease inhibitors.

    Science.gov (United States)

    Hameed, Abdul; Khan, Khalid Mohammed; Zehra, Syeda Tazeen; Ahmed, Ramasa; Shafiq, Zahid; Bakht, Syeda Mahwish; Yaqub, Muhammad; Hussain, Mazhar; de la Vega de León, Antonio; Furtmann, Norbert; Bajorath, Jürgen; Shad, Hazoor Ahmad; Tahir, Muhammad Nawaz; Iqbal, Jamshed

    2015-08-01

    Urease is an important enzyme which breaks urea into ammonia and carbon dioxide during metabolic processes. However, an elevated activity of urease causes various complications of clinical importance. The inhibition of urease activity with small molecules as inhibitors is an effective strategy for therapeutic intervention. Herein, we have synthesized a series of 19 benzofurane linked N-phenyl semithiocarbazones (3a-3s). All the compounds were screened for enzyme inhibitor activity against Jack bean urease. The synthesized N-phenyl thiosemicarbazones had varying activity levels with IC50 values between 0.077 ± 0.001 and 24.04 ± 0.14 μM compared to standard inhibitor, thiourea (IC50 = 21 ± 0.11 μM). The activities of these compounds may be due to their close resemblance of thiourea. A docking study with Jack bean urease (PDB ID: 4H9M) revealed possible binding modes of N-phenyl thiosemicarbazones. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Design, synthesis and optimization of bis-amide derivatives as CSF1R inhibitors.

    Science.gov (United States)

    Ramachandran, Sreekanth A; Jadhavar, Pradeep S; Miglani, Sandeep K; Singh, Manvendra P; Kalane, Deepak P; Agarwal, Anil K; Sathe, Balaji D; Mukherjee, Kakoli; Gupta, Ashu; Haldar, Srijan; Raja, Mohd; Singh, Siddhartha; Pham, Son M; Chakravarty, Sarvajit; Quinn, Kevin; Belmar, Sebastian; Alfaro, Ivan E; Higgs, Christopher; Bernales, Sebastian; Herrera, Francisco J; Rai, Roopa

    2017-05-15

    Signaling via the receptor tyrosine kinase CSF1R is thought to play an important role in recruitment and differentiation of tumor-associated macrophages (TAMs). TAMs play pro-tumorigenic roles, including the suppression of anti-tumor immune response, promotion of angiogenesis and tumor cell metastasis. Because of the role of this signaling pathway in the tumor microenvironment, several small molecule CSF1R kinase inhibitors are undergoing clinical evaluation for cancer therapy, either as a single agent or in combination with other cancer therapies, including immune checkpoint inhibitors. Herein we describe our lead optimization effort that resulted in the identification of a potent, cellular active and orally bioavailable bis-amide CSF1R inhibitor. Docking and biochemical analysis allowed the removal of a metabolically labile and poorly permeable methyl piperazine group from an early lead compound. Optimization led to improved metabolic stability and Caco2 permeability, which in turn resulted in good oral bioavailability in mice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Sirtuin-1 regulates acinar-to-ductal metaplasia and supports cancer cell viability in pancreatic cancer.

    Science.gov (United States)

    Wauters, Elke; Sanchez-Arévalo Lobo, Victor J; Pinho, Andreia V; Mawson, Amanda; Herranz, Daniel; Wu, Jianmin; Cowley, Mark J; Colvin, Emily K; Njicop, Erna Ngwayi; Sutherland, Rob L; Liu, Tao; Serrano, Manuel; Bouwens, Luc; Real, Francisco X; Biankin, Andrew V; Rooman, Ilse

    2013-04-01

    The exocrine pancreas can undergo acinar-to-ductal metaplasia (ADM), as in the case of pancreatitis where precursor lesions of pancreatic ductal adenocarcinoma (PDAC) can arise. The NAD(+)-dependent protein deacetylase Sirtuin-1 (Sirt1) has been implicated in carcinogenesis with dual roles depending on its subcellular localization. In this study, we examined the expression and the role of Sirt1 in different stages of pancreatic carcinogenesis, i.e. ADM models and established PDAC. In addition, we analyzed the expression of KIAA1967, a key mediator of Sirt1 function, along with potential Sirt1 downstream targets. Sirt1 was co-expressed with KIAA1967 in the nuclei of normal pancreatic acinar cells. In ADM, Sirt1 underwent a transient nuclear-to-cytoplasmic shuttling. Experiments where during ADM, we enforced repression of Sirt1 shuttling, inhibition of Sirt1 activity or modulation of its expression, all underscore that the temporary decrease of nuclear and increase of cytoplasmic Sirt1 stimulate ADM. Our results further underscore that important transcriptional regulators of acinar differentiation, that is, Pancreatic transcription factor-1a and β-catenin can be deacetylated by Sirt1. Inhibition of Sirt1 is effective in suppression of ADM and in reducing cell viability in established PDAC tumors. KIAA1967 expression is differentially downregulated in PDAC and impacts on the sensitivity of PDAC cells to the Sirt1/2 inhibitor Tenovin-6. In PDAC, acetylation of β-catenin is not affected, unlike p53, a well-characterized Sirt1-regulated protein in tumor cells. Our results reveal that Sirt1 is an important regulator and potential therapeutic target in pancreatic carcinogenesis. ©2012 AACR.

  14. Sirtuin1 Maintains Actin Cytoskeleton by Deacetylation of Cortactin in Injured Podocytes

    Science.gov (United States)

    Motonishi, Shuta; Wada, Takehiko; Ishimoto, Yu; Ohse, Takamoto; Matsusaka, Taiji; Kubota, Naoto; Shimizu, Akira; Kadowaki, Takashi; Tobe, Kazuyuki

    2015-01-01

    Recent studies have highlighted the renoprotective effect of sirtuin1 (SIRT1), a deacetylase that contributes to cellular regulation. However, the pathophysiologic role of SIRT1 in podocytes remains unclear. Here, we investigated the function of SIRT1 in podocytes. We first established podocyte-specific Sirt1 knockout (SIRT1pod−/−) mice. We then induced glomerular disease by nephrotoxic serum injection. The increase in urinary albumin excretion and BUN and the severity of glomerular injury were all significantly greater in SIRT1pod−/− mice than in wild-type mice. Western blot analysis and immunofluorescence showed a significant decrease in podocyte-specific proteins in SIRT1pod−/− mice, and electron microscopy showed marked exacerbation of podocyte injury, including actin cytoskeleton derangement in SIRT1pod−/− mice compared with wild-type mice. Protamine sulfate-induced podocyte injury was also exacerbated by podocyte-specific SIRT1 deficiency. In vitro, actin cytoskeleton derangement in H2O2-treated podocytes became prominent when the cells were pretreated with SIRT1 inhibitors. Conversely, this H2O2-induced derangement was ameliorated by SIRT1 activation. Furthermore, SIRT1 activation deacetylated the actin-binding and -polymerizing protein cortactin in the nucleus and facilitated deacetylated cortactin localization in the cytoplasm. Cortactin knockdown or inhibition of the nuclear export of cortactin induced actin cytoskeleton derangement and dissociation of cortactin from F-actin, suggesting the necessity of cytoplasmic cortactin for maintenance of the actin cytoskeleton. Taken together, these findings indicate that SIRT1 protects podocytes and prevents glomerular injury by deacetylating cortactin and thereby, maintaining actin cytoskeleton integrity. PMID:25424328

  15. Synthesis of [[sup 18]F]-(S)-fluoxetine: a selective serotonine uptake inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Hammadi, A.; Crouzel, C. (CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot)

    1993-01-01

    The (S)-N-methyl-[gamma]-[4-(trifluoromethyl)phenoxy] benzenepropanamine, an antidepressant with potential applications in the treatment of other illnesses was labelled with fluorine-18 for Positron Emission Tomography studies. The synthesis was accomplished from the [[sup 18]F]-4-chlorobenzotrifluoride where [[sup 18]F]-label was introduced via a nucleophilic aliphatic substitution reaction. [[sup 18]F]-(S)-Fluoxetine was obtained with a radiochemical yield of 9-10% (decay corrected) and a specific radioactivity of 100-150 mCi/[mu]mol (3.70-5.55 GBq/[mu]mol) in a total synthesis time of 150 min. A facile isotopic exchange reaction was demonstrated; it is expected to reduce the specific activity of the final [[sup 18]F]-product. The experimental parameters play an important role, which is discussed. (Author).

  16. Synthesis of [18F]-(S)-fluoxetine: a selective serotonine uptake inhibitor

    International Nuclear Information System (INIS)

    Hammadi, A.; Crouzel, C.

    1993-01-01

    The (S)-N-methyl-γ-[4-(trifluoromethyl)phenoxy] benzenepropanamine, an antidepressant with potential applications in the treatment of other illnesses was labelled with fluorine-18 for Positron Emission Tomography studies. The synthesis was accomplished from the [ 18 F]-4-chlorobenzotrifluoride where [ 18 F]-label was introduced via a nucleophilic aliphatic substitution reaction. [ 18 F]-(S)-Fluoxetine was obtained with a radiochemical yield of 9-10% (decay corrected) and a specific radioactivity of 100-150 mCi/μmol (3.70-5.55 GBq/μmol) in a total synthesis time of 150 min. A facile isotopic exchange reaction was demonstrated; it is expected to reduce the specific activity of the final [ 18 F]-product. The experimental parameters play an important role, which is discussed. (Author)

  17. Synthesis of 2-(6-Acetamidobenzothiazolethioacetic Acid Esters as Photosynthesis Inhibitors

    Directory of Open Access Journals (Sweden)

    Dusan Loos

    1998-04-01

    Full Text Available The synthesis and photosynthesis-inhibiting activity of 13 new 2-(6-acetamidobenzothiazolethioacetic acid esters are reported. The new compounds were prepared by acetylation of 2-(alkoxycarbonylmethylthio-6-aminobenzothiazoles with acetic anhydride. The structure of the compounds was verified by 1H NMR spectra. The compounds inhibit photosynthetic electron transfer in spinach chloroplasts. The structure - activity relation was studied. Lipophilicity was found to influence substantially photosynthetic electron transfer.

  18. Next Generation Biofilm Inhibitors for Pseudomonas aeruginosa: Synthesis and Rational Design Approaches

    Digital Repository Service at National Institute of Oceanography (India)

    Majik, M.S.; Parvatkar, P.T.

    infection. (14) Urinary stent infection. (15) Intravascular stent infection. (16) Pulmonary infection in cystic fibrosis patient. (17) Ventilator associated pneumonia. (18) Breast implant infection. The formation of biofilms is dynamic and complicated... as that of ageliferin skeleton would show any effect on antibiofilm properties, Melander and co-workers continued their effort towards synthesis of library of oroidin family. Initially, the libraries of oroidin core scaffolds were constructed by varying three regions...

  19. A Stepwise Approach for the Synthesis of Folic Acid Conjugates with Protein Kinase Inhibitors

    Czech Academy of Sciences Publication Activity Database

    Krajčovičová, S.; Gucký, Tomáš; Hendrychová, Denisa; Kryštof, Vladimír; Soural, M.

    2017-01-01

    Roč. 82, č. 24 (2017), s. 13530-13541 ISSN 0022-3263 R&D Projects: GA ČR(CZ) GA15-15264S; GA MŠk(CZ) LO1304 Institutional support: RVO:61389030 Keywords : CYCLIN-DEPENDENT KINASES * FOLATE RECEPTOR * REGIOSELECTIVE SYNTHESIS Subject RIV: FR - Pharmacology ; Medidal Chemistry OBOR OECD: Organic chemistry Impact factor: 4.849, year: 2016

  20. Design, synthesis, X-ray studies, and biological evaluation of novel macrocyclic HIV-1 protease inhibitors involving the P1'-P2' ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Sean Fyvie, W.; Brindisi, Margherita; Steffey, Melinda; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Amano, Masayuki; Weber, Irene T.; Mitsuya, Hiroaki

    2017-11-01

    Design, synthesis, and evaluation of a new class of HIV-1 protease inhibitors containing diverse flexible macrocyclic P1'-P2' tethers are reported. Inhibitor 5a with a pyrrolidinone-derived macrocycle exhibited favorable enzyme inhibitory and antiviral activity (Ki = 13.2 nM, IC50 = 22 nM). Further incorporation of heteroatoms in the macrocyclic skeleton provided macrocyclic inhibitors 5m and 5o. These compounds showed excellent HIV-1 protease inhibitory (Ki = 62 pM and 14 pM, respectively) and antiviral activity (IC50 = 5.3 nM and 2.0 nM, respectively). Inhibitor 5o also remained highly potent against a DRV-resistant HIV-1 variant.

  1. Acquisition of a potent and selective TC-PTP inhibitor via a stepwise fluorophore-tagged combinatorial synthesis and screening strategy.

    Science.gov (United States)

    Zhang, Sheng; Chen, Lan; Luo, Yong; Gunawan, Andrea; Lawrence, David S; Zhang, Zhong-Yin

    2009-09-16

    Protein tyrosine phosphatases (PTPs) regulate a broad range of cellular processes including proliferation, differentiation, migration, apoptosis, and immune responses. Dysfunction of PTP activity is associated with cancers, metabolic syndromes, and autoimmune disorders. Consequently, small molecule PTP inhibitors should serve not only as powerful tools to delineate the physiological roles of these enzymes in vivo but also as lead compounds for therapeutic development. We describe a novel stepwise fluorophore-tagged combinatorial library synthesis and competitive fluorescence polarization screening approach that transforms a weak and general PTP inhibitor into an extremely potent and selective TC-PTP inhibitor with highly efficacious cellular activity. The result serves as a proof-of-concept in PTP inhibitor development, as it demonstrates the feasibility of acquiring potent, yet highly selective, cell permeable PTP inhibitory agents. Given the general nature of the approach, this strategy should be applicable to other PTP targets.

  2. Glutaredoxin-1 Deficiency Causes Fatty Liver and Dyslipidemia by Inhibiting Sirtuin-1

    Science.gov (United States)

    Shao, Di; Han, Jingyan; Hou, Xiuyun; Fry, Jessica; Behring, Jessica B.; Seta, Francesca; Long, Michelle T.; Roy, Hemant K.; Cohen, Richard A.

    2017-01-01

    Abstract Aims: Nonalcoholic fatty liver (NAFL) is a common liver disease associated with metabolic syndrome, obesity, and diabetes that is rising in prevalence worldwide. Various molecular perturbations of key regulators and enzymes in hepatic lipid metabolism cause NAFL. However, redox regulation through glutathione (GSH) adducts in NAFL remains largely elusive. Glutaredoxin-1 (Glrx) is a small thioltransferase that removes protein GSH adducts without having direct antioxidant properties. The liver contains abundant Glrx but its metabolic function is unknown. Results: Here we report that normal diet-fed Glrx-deficient mice (Glrx−/−) spontaneously develop obesity, hyperlipidemia, and hepatic steatosis by 8 months of age. Adenoviral Glrx repletion in the liver of Glrx−/− mice corrected lipid metabolism. Glrx−/− mice exhibited decreased sirtuin-1 (SirT1) activity that leads to hyperacetylation and activation of SREBP-1 and upregulation of key hepatic enzymes involved in lipid synthesis. We found that GSH adducts inhibited SirT1 activity in Glrx−/− mice. Hepatic expression of nonoxidizable cysteine mutant SirT1 corrected hepatic lipids in Glrx−/− mice. Wild-type mice fed high-fat diet develop metabolic syndrome, diabetes, and NAFL within several months. Glrx deficiency accelerated high-fat-induced NAFL and progression to steatohepatitis, manifested by hepatic damage and inflammation. Innovation: These data suggest an essential role of hepatic Glrx in regulating SirT1, which controls protein glutathione adducts in the pathogenesis of hepatic steatosis. Conclusion: We provide a novel redox-dependent mechanism for regulation of hepatic lipid metabolism, and propose that upregulation of hepatic Glrx may be a beneficial strategy for NAFL. Antioxid. Redox Signal. 27, 313–327. PMID:27958883

  3. Overexpression of mitochondrial sirtuins alters glycolysis and mitochondrial function in HEK293 cells.

    Directory of Open Access Journals (Sweden)

    Michelle Barbi de Moura

    Full Text Available SIRT3, SIRT4, and SIRT5 are mitochondrial deacylases that impact multiple facets of energy metabolism and mitochondrial function. SIRT3 activates several mitochondrial enzymes, SIRT4 represses its targets, and SIRT5 has been shown to both activate and repress mitochondrial enzymes. To gain insight into the relative effects of the mitochondrial sirtuins in governing mitochondrial energy metabolism, SIRT3, SIRT4, and SIRT5 overexpressing HEK293 cells were directly compared. When grown under standard cell culture conditions (25 mM glucose all three sirtuins induced increases in mitochondrial respiration, glycolysis, and glucose oxidation, but with no change in growth rate or in steady-state ATP concentration. Increased proton leak, as evidenced by oxygen consumption in the presence of oligomycin, appeared to explain much of the increase in basal oxygen utilization. Growth in 5 mM glucose normalized the elevations in basal oxygen consumption, proton leak, and glycolysis in all sirtuin over-expressing cells. While the above effects were common to all three mitochondrial sirtuins, some differences between the SIRT3, SIRT4, and SIRT5 expressing cells were noted. Only SIRT3 overexpression affected fatty acid metabolism, and only SIRT4 overexpression altered superoxide levels and mitochondrial membrane potential. We conclude that all three mitochondrial sirtuins can promote increased mitochondrial respiration and cellular metabolism. SIRT3, SIRT4, and SIRT5 appear to respond to excess glucose by inducing a coordinated increase of glycolysis and respiration, with the excess energy dissipated via proton leak.

  4. Sirtuins: Molecular Traffic Lights in the Crossroad of Oxidative Stress, Chromatin Remodeling, and Transcription

    Directory of Open Access Journals (Sweden)

    Ramkumar Rajendran

    2011-01-01

    Full Text Available Transcription is regulated by acetylation/deacetylation reactions of histone and nonhistone proteins mediated by enzymes called KATs and HDACs, respectively. As a major mechanism of transcriptional regulation, protein acetylation is a key controller of physiological processes such as cell cycle, DNA damage response, metabolism, apoptosis, and autophagy. The deacetylase activity of class III histone deacetylases or sirtuins depends on the presence of NAD+ (nicotinamide adenine dinucleotide, and therefore, their function is closely linked to cellular energy consumption. This activity of sirtuins connects the modulation of chromatin dynamics and transcriptional regulation under oxidative stress to cellular lifespan, glucose homeostasis, inflammation, and multiple aging-related diseases including cancer. Here we provide an overview of the recent developments in relation to the diverse biological activities associated with sirtuin enzymes and stress responsive transcription factors, DNA damage, and oxidative stress and relate the involvement of sirtuins in the regulation of these processes to oncogenesis. Since the majority of the molecular mechanisms implicated in these pathways have been described for Sirt1, this sirtuin family member is more extensively presented in this paper.

  5. Metabolic control by sirtuins and other enzymes that sense NAD+, NADH, or their ratio.

    Science.gov (United States)

    Anderson, Kristin A; Madsen, Andreas S; Olsen, Christian A; Hirschey, Matthew D

    2017-12-01

    NAD + is a dinucleotide cofactor with the potential to accept electrons in a variety of cellular reduction-oxidation (redox) reactions. In its reduced form, NADH is a ubiquitous cellular electron donor. NAD + , NADH, and the NAD + /NADH ratio have long been known to control the activity of several oxidoreductase enzymes. More recently, enzymes outside those participating directly in redox control have been identified that sense these dinucleotides, including the sirtuin family of NAD + -dependent protein deacylases. In this review, we highlight examples of non-redox enzymes that are controlled by NAD + , NADH, or NAD + /NADH. In particular, we focus on the sirtuin family and assess the current evidence that the sirtuin enzymes sense these dinucleotides and discuss the biological conditions under which this might occur; we conclude that sirtuins sense NAD + , but neither NADH nor the ratio. Finally, we identify future studies that might be informative to further interrogate physiological and pathophysiological changes in NAD + and NADH, as well as enzymes like sirtuins that sense and respond to redox changes in the cell. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Synthesis, kinetic mechanism and docking studies of vanillin derivatives as inhibitors of mushroom tyrosinase.

    Science.gov (United States)

    Ashraf, Zaman; Rafiq, Muhammad; Seo, Sung-Yum; Babar, Mustafeez Mujtaba; Zaidi, Najam-us-Sahar Sadaf

    2015-09-01

    The purpose of the present study was to discover the extent of contribution to antityrosinase activity by adding hydroxy substituted benzoic acid, cinnamic acid and piperazine residues to vanillin. The study showed the transformation of vanillin into esters as shown in (4a-4d), (6a-6b), and (8a-8b). In addition, the relationship between structures of these esters and their mushroom tyrosinase inhibitory activity was explored. The kinetics of inhibition on mushroom tyrosinase by these esters was also investigated. It was found that hydroxyl substituted benzoic acid derivatives were weak inhibitors; however hydroxy or chloro substituted cinnamic acid and piperazine substituted derivatives were able to induce significant tyrosinase inhibition. The mushroom tyrosinase (PDBID 2ZWE) was docked with synthesized vanillin derivatives and their calculated binding energies were compared with experimental IC50 values which provided positive correlation. The most potent derivative 2-(4-formyl-2-methoxyphenoxy)-2-oxoethyl (2E)-3-(4-hydroxyphenyl)prop-2-enoate (6a) possesses hydroxy substituted cinnamic acid scaffold having IC50 value 16.13 μM with binding energy of -7.2 kcal/mol. The tyrosinase inhibitory activity of (6a) is comparable with standard kojic acid. Kinetic analysis indicated that compound 6a was mixed-type tyrosinase inhibitor with inhibition constant values Ki (13 μM) and Ki' (53 μM) and formed reversible enzyme inhibitor complex. The active vanillin analog (6a) was devoid of toxic effects as shown in cytotoxic studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. A Concise Total Synthesis of (R)-Fluoxetine, a Potent and Selective Serotonin Reuptake Inhibitor

    OpenAIRE

    de Fátima, Ângelo; Lapis, Alexandre Augusto M.; Pilli, Ronaldo A.

    2005-01-01

    (R)-Fluoxetine, potent and selective serotonin reuptake inhibitor, has been synthesized in six steps, 50% overall yield and 99% ee from benzaldehyde via catalytic asymmetric allylation with Maruoka's catalyst. (R)-Fluoxetina, um inibidor potente e seletivo da recaptação da serotonina, foi sintetizada em seis etapas, 50% de rendimento total e 99% de excesso enantiomérico a partir do benzaldeído via alilação catalítica assimétrica empregando-se o sistema catalítico desenvolvido por Maruoka e...

  8. Benzoxazolone carboxamides as potent acid ceramidase inhibitors: Synthesis and structure-activity relationship (SAR) studies

    DEFF Research Database (Denmark)

    Bach, Anders

    2015-01-01

    be useful in the treatment of pathological conditions, such as cancer, in which ceramide levels are abnormally reduced. Here, we present a systematic SAR investigation of the benzoxazolone carboxamides, a recently described class of AC inhibitors that display high potency and systemic activity in mice. We...... examined a diverse series of substitutions on both benzoxazolone ring and carboxamide side chain. Several modifications enhanced potency and stability, and one key compound with a balanced activity-stability profile (14) was found to inhibit AC activity in mouse lungs and cerebral cortex after systemic...

  9. Substituted 3-Benzylcoumarins as Allosteric MEK1 Inhibitors: Design, Synthesis and Biological Evaluation as Antiviral Agents

    Directory of Open Access Journals (Sweden)

    Ping Xu

    2013-05-01

    Full Text Available In order to find novel antiviral agents, a series of allosteric MEK1 inhibitors were designed and synthesized. Based on docking results, multiple optimizations were made on the coumarin scaffold. Some of the derivatives showed excellent MEK1 binding affinity in the appropriate enzymatic assays and displayed obvious inhibitory effects on the ERK pathway in a cellular assay. These compounds also significantly inhibited virus (EV71 replication in HEK293 and RD cells. Several compounds showed potential as agents for the treatment of viral infective diseases, with the most potent compound 18 showing an IC50 value of 54.57 nM in the MEK1 binding assay.

  10. Design and Synthesis of Brain Penetrant Trypanocidal N-Myristoyltransferase Inhibitors.

    Science.gov (United States)

    Bayliss, Tracy; Robinson, David A; Smith, Victoria C; Brand, Stephen; McElroy, Stuart P; Torrie, Leah S; Mpamhanga, Chido; Norval, Suzanne; Stojanovski, Laste; Brenk, Ruth; Frearson, Julie A; Read, Kevin D; Gilbert, Ian H; Wyatt, Paul G

    2017-12-14

    N-Myristoyltransferase (NMT) represents a promising drug target within the parasitic protozoa Trypanosoma brucei (T. brucei), the causative agent for human African trypanosomiasis (HAT) or sleeping sickness. We have previously validated T. brucei NMT as a promising druggable target for the treatment of HAT in both stages 1 and 2 of the disease. We report on the use of the previously reported DDD85646 (1) as a starting point for the design of a class of potent, brain penetrant inhibitors of T. brucei NMT.

  11. Novel amide derivatives as inhibitors of histone deacetylase: design, synthesis and SAR

    DEFF Research Database (Denmark)

    Andrianov, V.; Gailite, V.; Lola, D.

    2009-01-01

    Enzymatic inhibition of histone deacetylase (HDAC) activity is emerging as an innovative and effective approach for the treatment of cancer. A series of novel amide derivatives have been synthesized and evaluated for their ability to inhibit human HDACs. Multiple compounds were identified as potent...... HDAC inhibitors (HDACi), with IC(50) values in the low nanomolar (nM) range against enzyme activity in HeLa cell extracts and sub-microM for their in vitro anti-proliferative effect on cell lines. The introduction of an unsaturated linking group between the terminal aryl ring and the amide moiety...

  12. Synthesis of (benzimidazol-2-yl)aniline derivatives as glycogen phosphorylase inhibitors.

    Science.gov (United States)

    Galal, Shadia A; Khattab, Muhammad; Andreadaki, Fotini; Chrysina, Evangelia D; Praly, Jean-Pierre; Ragab, Fatma A F; El Diwani, Hoda I

    2016-11-01

    A series of (benzimidazol-2-yl)-aniline (1) derivatives has been synthesized and evaluated as glycogen phosphorylase (GP) inhibitors. Kinetics studies revealed that compounds displaying a lateral heterocyclic residue with several heteroatoms (series 3 and 5) exhibited modest inhibitory properties with IC 50 values in the 400-600μM range. Arylsulfonyl derivatives 7 (Ar: phenyl) and 9 (Ar: o-nitrophenyl) of 1 exhibited the highest activity (series 2) among the studied compounds (IC 50 324μM and 357μM, respectively) with stronger effect than the p-tolyl analogue 8. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Potent new small-molecule inhibitor of botulinum neurotoxin serotype A endopeptidase developed by synthesis-based computer-aided molecular design.

    Directory of Open Access Journals (Sweden)

    Yuan-Ping Pang

    2009-11-01

    Full Text Available Botulinum neurotoxin serotype A (BoNTA causes a life-threatening neuroparalytic disease known as botulism. Current treatment for post exposure of BoNTA uses antibodies that are effective in neutralizing the extracellular toxin to prevent further intoxication but generally cannot rescue already intoxicated neurons. Effective small-molecule inhibitors of BoNTA endopeptidase (BoNTAe are desirable because such inhibitors potentially can neutralize the intracellular BoNTA and offer complementary treatment for botulism. Previously we reported a serotype-selective, small-molecule BoNTAe inhibitor with a K(i (app value of 3.8+/-0.8 microM. This inhibitor was developed by lead identification using virtual screening followed by computer-aided optimization of a lead with an IC(50 value of 100 microM. However, it was difficult to further improve the lead from micromolar to even high nanomolar potency due to the unusually large enzyme-substrate interface of BoNTAe. The enzyme-substrate interface area of 4,840 A(2 for BoNTAe is about four times larger than the typical protein-protein interface area of 750-1,500 A(2. Inhibitors must carry several functional groups to block the unusually large interface of BoNTAe, and syntheses of such inhibitors are therefore time-consuming and expensive. Herein we report the development of a serotype-selective, small-molecule, and competitive inhibitor of BoNTAe with a K(i value of 760+/-170 nM using synthesis-based computer-aided molecular design (SBCAMD. This new approach accounts the practicality and efficiency of inhibitor synthesis in addition to binding affinity and selectivity. We also report a three-dimensional model of BoNTAe in complex with the new inhibitor and the dynamics of the complex predicted by multiple molecular dynamics simulations, and discuss further structural optimization to achieve better in vivo efficacy in neutralizing BoNTA than those of our early micromolar leads. This work provides new insight

  14. Synthesis and structure activity relationships of carbamimidoylcarbamate derivatives as novel vascular adhesion protein-1 inhibitors.

    Science.gov (United States)

    Yamaki, Susumu; Yamada, Hiroyoshi; Nagashima, Akira; Kondo, Mitsuhiro; Shimada, Yoshiaki; Kadono, Keitaro; Yoshihara, Kosei

    2017-11-01

    Vascular adhesion protein-1 (VAP-1) is a promising therapeutic target for the treatment of diabetic nephropathy. Here, we conducted structural optimization of the glycine amide derivative 1, which we previously reported as a novel VAP-1 inhibitor, to improve stability in dog and monkey plasma, and aqueous solubility. By chemical modification of the right part in the glycine amide derivative, we identified the carbamimidoylcarbamate derivative 20c, which showed stability in dog and monkey plasma while maintaining VAP-1 inhibitory activity. We also found that conversion of the pyrimidine ring in 20c into saturated rings was effective for improving aqueous solubility. This led to the identification of 28a and 35 as moderate VAP-1 inhibitors with excellent aqueous solubility. Further optimization led to the identification of 2-fluoro-3-{3-[(6-methylpyridin-3-yl)oxy]azetidin-1-yl}benzyl carbamimidoylcarbamate (40b), which showed similar human VAP-1 inhibitory activity to 1 with improved aqueous solubility. 40b showed more potent ex vivo efficacy than 1, with rat plasma VAP-1 inhibitory activity of 92% at 1h after oral administration at 0.3mg/kg. In our pharmacokinetic study, 40b showed good oral bioavailability in rats, dogs, and monkeys, which may be due to its improved stability in dog and monkey plasma. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Synthesis of Dipeptide Benzoylalanylglycine Methyl Ester and Corrosion Inhibitor Evaluation by Tafel Equation

    International Nuclear Information System (INIS)

    Abdurrahman, J.; Wahyuningrum, D.; Achmad, S.; Bundjali, B.

    2011-01-01

    Corrosion is one of the major problems in petroleum mining and processing industry. The pipelines used to transport crude oil from reservoir to the processing installation were made from carbon steel that is susceptible towards corrosion. One of the best methods to prevent corrosion that occurred at the inner parts of carbon steel pipelines is to use organic corrosion inhibitor. One of the potent organic corrosion inhibitors is amino acids derivatives. In this study, dipeptide compound namely benzoylalanylglycine methyl ester and benzoylalanylglycine have been synthesized. The structure elucidation of the products was performed by IR, MS and NMR spectroscopy. The determination of corrosion inhibition activity utilized the Tafel method. The corrosion inhibition efficiency of glycine methyl ester, benzoyl alanine, dipeptide benzoylalanylglycine methyl ester and dipeptide benzoylalanylglycine were 63.34 %, 35.86 %, 68.40 % and 27.72 %, respectively. These results showed that the formation of dipeptide benzoylalanylglycine methyl ester, derived from carboxylic protected glycine and amine protected alanine, increased the corrosion inhibition activity due to the loss of acidity center in the structure of glycine and L-alanine that would induce the corrosive environment towards carbon steel. (author)

  16. Cyclooxygenase-2 inhibitors. Synthesis and pharmacological activities of 5-methanesulfonamido-1-indanone derivatives.

    Science.gov (United States)

    Li, C S; Black, W C; Chan, C C; Ford-Hutchinson, A W; Gauthier, J Y; Gordon, R; Guay, D; Kargman, S; Lau, C K; Mancini, J

    1995-12-08

    The recent discovery of an alternative form cyclooxygenase (cyclooxygenase-2, COX-2), which has been proposed to play a significant role in inflammatory conditions, may provide an opportunity to develop anti-inflammatory drugs with fewer side effects than existing non-steroidal anti-inflammatory drugs (NSAIDs). We have now identified 6-[(2,4-difluorophenyl)-thio]-5-methanesulfonamido-1-indanone++ + (20) (L-745,337) as a potent, selective, and orally active COX-2 inhibitor. The structure-activity relationships in this series have been extensively studied. Ortho- and para-substituted 6-phenyl substitutents are optimal for in vitro potency. Replacement of this phenyl ring by a variety of heterocycles gave compounds that were less active. The methanesulfonamido group seems to be the optimal group at the 5-position of the indanone system. Compound 20 has an efficacy profile that is superior or comparable to that of the nonselective COX inhibitor indomethacin in animal models of inflammation, pain, and fever and appears to be nonulcerogenic within the dosage ranges required for functional efficacy. Although 20 and its oxygen linkage analog 2 (flosulide) are equipotent in the in vitro assays, compound 20 is more potent in the rat paw edema assay, has a longer t1/2 in squirrel monkeys, and seems less ulcergenic than 2 in rats.

  17. Synthesis and molecular docking study of piperazine derivatives as potent urease inhibitors.

    Science.gov (United States)

    Taha, Muhammad; Wadood, Abdul

    2018-04-13

    Urease is known to be one of the major causes of diseases induced by Helicobacter pylori, thus allow them to survive at low pH inside the stomach and thereby, play an important role in the pathogenesis of gastric and peptic ulcer, apart from cancer as well. Keeping in view the great importance of urease inhibitors, here in this study we have synthesized piperazine derivatives (1-15) and evaluated for their urease inhibitory activity. All analogs showed excellent inhibitory potential with IC 50 values ranging between 1.1 ± 0.01 and 33.40 ± 1.50 µM when compared with the standard inhibitor thiourea (IC 50  = 21.30 ± 1.10 µM). Structure activity relationship has been established for all compounds which are mainly based upon the substitution on phenyl ring. Molecular docking study was performed in order to understand the binding interaction of the compounds in the active site of enzyme. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Cutaneous effects of topical indomethacin, an inhibitor of prostaglandin synthesis, on uv-damaged skin

    International Nuclear Information System (INIS)

    Snyder, D.S.

    1975-01-01

    Topical application of a 2.5 percent indomethacin (IM) solution to the sunburned skin of humans and guinea pigs resulted in a marked decrease in ultraviolet light (UVL)-induced erythema. In humans, a decrease in skin temperature and hyperalgesia to near normal levels was also observed. Epidermal responses to UVL injury such as keratinocyte cell death and altered DNA synthesis proceeded unmodified by IM. Repeated applications of IM in the 48-hr period following UVL exposure did not improve upon the results obtained following a single treatment. Guinea-pig skin provides a relevant model system for evaluating the effects of topical nonsteroidal anti-inflammatory agents on sunburn

  19. The mechanisms of sirtuin 2-mediated exacerbation of alpha-synuclein toxicity in models of Parkinson disease

    Science.gov (United States)

    Sirtuin genes have been associated with aging and are known to affect multiple cellular pathways. Sirtuin 2 was previously shown to modulate proteotoxicity associated with age-associated neurodegenerative disorders such as Alzheimer and Parkinson disease (PD). However, the precise molecular mechanis...

  20. Dihydroquinazolines as a novel class of Trypanosoma brucei trypanothione reductase inhibitors: discovery, synthesis, and characterization of their binding mode by protein crystallography.

    Science.gov (United States)

    Patterson, Stephen; Alphey, Magnus S; Jones, Deuan C; Shanks, Emma J; Street, Ian P; Frearson, Julie A; Wyatt, Paul G; Gilbert, Ian H; Fairlamb, Alan H

    2011-10-13

    Trypanothione reductase (TryR) is a genetically validated drug target in the parasite Trypanosoma brucei , the causative agent of human African trypanosomiasis. Here we report the discovery, synthesis, and development of a novel series of TryR inhibitors based on a 3,4-dihydroquinazoline scaffold. In addition, a high resolution crystal structure of TryR, alone and in complex with substrates and inhibitors from this series, is presented. This represents the first report of a high resolution complex between a noncovalent ligand and this enzyme. Structural studies revealed that upon ligand binding the enzyme undergoes a conformational change to create a new subpocket which is occupied by an aryl group on the ligand. Therefore, the inhibitor, in effect, creates its own small binding pocket within the otherwise large, solvent exposed active site. The TryR-ligand structure was subsequently used to guide the synthesis of inhibitors, including analogues that challenged the induced subpocket. This resulted in the development of inhibitors with improved potency against both TryR and T. brucei parasites in a whole cell assay.

  1. Epitope-Targeting of Tertiary Protein Structure Enables Target-Guided Synthesis of a Potent in Cell Inhibitor of Botulinum Neurotoxin**

    OpenAIRE

    Farrow, Blake; Wong, Michelle; Malette, Jacquie; Lai, Bert; Deyle, Kaycie M.; Das, Samir; Nag, Arundhati; Agnew, Heather D.; Heath, James R.

    2015-01-01

    Botulinum neurotoxin (BoNT) serotype A is the most lethal known toxin and has an occluded structure, which prevents direct inhibition of its active site before it enters the cytosol. Target-guided synthesis by in situ click chemistry is combined with synthetic epitope targeting to exploit the tertiary structure of the BoNT protein as a landscape for assembling a competitive inhibitor. A substrate-mimicking peptide macrocycle is used as a direct inhibitor of BoNT. An epitope-targeting in situ ...

  2. Increased podocyte Sirtuin-1 function attenuates diabetic kidney injury.

    Science.gov (United States)

    Hong, Quan; Zhang, Lu; Das, Bhaskar; Li, Zhengzhe; Liu, Bohan; Cai, Guangyan; Chen, Xiangmei; Chuang, Peter Y; He, John Cijiang; Lee, Kyung

    2018-06-01

    Podocyte injury and loss contribute to the progression of glomerular diseases, including diabetic kidney disease. We previously found that the glomerular expression of Sirtuin-1 (SIRT1) is reduced in human diabetic glomeruli and that the podocyte-specific loss of SIRT1 aggravated albuminuria and worsened kidney disease progression in diabetic mice. SIRT1 encodes an NAD-dependent deacetylase that modifies the activity of key transcriptional regulators affected in diabetic kidneys, including NF-κB, STAT3, p53, FOXO4, and PGC1-α. However, whether the increased glomerular SIRT1 activity is sufficient to ameliorate the pathogenesis of diabetic kidney disease has not been explored. We addressed this by inducible podocyte-specific SIRT1 overexpression in diabetic OVE26 mice. The induction of SIRT1 overexpression in podocytes for six weeks in OVE26 mice with established albuminuria attenuated the progression of diabetic glomerulopathy. To further validate the therapeutic potential of increased SIRT1 activity against diabetic kidney disease, we developed a new, potent and selective SIRT1 agonist, BF175. In cultured podocytes BF175 increased SIRT1-mediated activation of PGC1-α and protected against high glucose-mediated mitochondrial injury. In vivo, administration of BF175 for six weeks in OVE26 mice resulted in a marked reduction in albuminuria and in glomerular injury in a manner similar to podocyte-specific SIRT1 overexpression. Both podocyte-specific SIRT1 overexpression and BT175 treatment attenuated diabetes-induced podocyte loss and reduced oxidative stress in glomeruli of OVE26 mice. Thus, increased SIRT1 activity protects against diabetes-induced podocyte injury and effectively mitigates the progression of diabetic kidney disease. Published by Elsevier Inc.

  3. Design, Synthesis and Evaluation of 3-(2-Aminoheterocycle-4-benzyloxyphenylbenzamide Derivatives as BACE-1 Inhibitors

    Directory of Open Access Journals (Sweden)

    Lushan Yu

    2013-03-01

    Full Text Available Three series of 3-(2-aminoheterocycle-4-benzyloxyphenylbenzamide derivatives, 2-aminooxazoles, 2-aminothiazoles, and 2-amino-6H-1,3,4-thiadizines were designed, synthesized and evaluated as β-secretase (BACE-1 inhibitors. Preliminary structure-activity relationships revealed that the existence of a 2-amino-6H-1,3,4-thiadizine moiety and α-naphthyl group were favorable for BACE-1 inhibition. Among the synthesized compounds, 5e exhibited the most potent BACE-1 inhibitory activity, with an IC50 value of 9.9 μΜ and it exhibited high brain uptake potential in Madin-Darby anine kidney cell lines (MDCK and a Madin-Darby canine kidney-multidrug resistance 1 (MDCK-MDR1 model.

  4. Design, synthesis and evaluation of 3-(2-aminoheterocycle)-4-benzyloxyphenylbenzamide derivatives as BACE-1 inhibitors.

    Science.gov (United States)

    Shangguan, Shihao; Wang, Fei; Liao, Yong; Yu, Haiping; Li, Jia; Huang, Wenhai; Hu, Haihong; Yu, Lushan; Hu, Yongzhou; Sheng, Rong

    2013-03-20

    Three series of 3-(2-aminoheterocycle)-4-benzyloxyphenylbenzamide derivatives, 2-aminooxazoles, 2-aminothiazoles, and 2-amino-6H-1,3,4-thiadizines were designed, synthesized and evaluated as β-secretase (BACE-1) inhibitors. Preliminary structure-activity relationships revealed that the existence of a 2-amino-6H-1,3,4-thiadizine moiety and α-naphthyl group were favorable for BACE-1 inhibition. Among the synthesized compounds, 5e exhibited the most potent BACE-1 inhibitory activity, with an IC50 value of 9.9 μΜ and it exhibited high brain uptake potential in Madin-Darby anine kidney cell lines (MDCK) and a Madin-Darby canine kidney-multidrug resistance 1 (MDCK-MDR1) model.

  5. Synthesis of some new 3-coumaranone and coumarin derivatives as dual inhibitors of acetyl- and butyrylcholinesterase.

    Science.gov (United States)

    Alipour, Masoumeh; Khoobi, Mehdi; Nadri, Hamid; Sakhteman, Amirhossein; Moradi, Alireza; Ghandi, Mehdi; Foroumadi, Alireza; Shafiee, Abbas

    2013-08-01

    A novel series of coumarin and 3-coumaranone derivatives encompassing the phenacyl pyridinium moiety were synthesized and evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activity using Ellman's method. All compounds presented inhibitory activity against both AChE and BuChE in the micromolar range. The molecular docking simulations revealed that all compounds were dual binding site inhibitors of AChE. A kinetic study was performed and the mechanism of enzyme inhibition was proved to be of mixed type. All compounds were tested for their antioxidant activity and no significant activity was observed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Design, Synthesis and Biological Evaluation of Novel Benzothiazole Derivatives as Selective PI3Kβ Inhibitors

    Directory of Open Access Journals (Sweden)

    Shuang Cao

    2016-07-01

    Full Text Available A novel series of PI3Kβ (Phosphatidylinositol-3-kinases beta subunit inhibitors with the structure of benzothiazole scaffold have been designed and synthesized. All the compounds have been evaluated for inhibitory activities against PI3Kα, β, γ, δ and mTOR (Mammalian target of rapamycin. Two superior compounds have been further evaluated for the IC50 values against PI3Ks/mTOR. The most promising compound 11 displays excellent anti-proliferative activity and selectivity in multiple cancer cell lines, especially in the prostate cancer cell line. Docking studies indicate the morpholine group in 2-position of benzothiazole is necessary for the potent antitumor activity, which confirms our design is reasonable.

  7. Evaluation of adamantane hydroxamates as botulinum neurotoxin inhibitors: synthesis, crystallography, modeling, kinetic and cellular based studies.

    Science.gov (United States)

    Šilhár, Peter; Silvaggi, Nicholas R; Pellett, Sabine; Čapková, Kateřina; Johnson, Eric A; Allen, Karen N; Janda, Kim D

    2013-03-01

    Botulinum neurotoxins (BoNTs) are the most lethal biotoxins known to mankind and are responsible for the neuroparalytic disease botulism. Current treatments for botulinum poisoning are all protein based and thus have a limited window of treatment opportunity. Inhibition of the BoNT light chain protease (LC) has emerged as a therapeutic strategy for the treatment of botulism as it may provide an effective post exposure remedy. Using a combination of crystallographic and modeling studies a series of hydroxamates derived from 1-adamantylacetohydroxamic acid (3a) were prepared. From this group of compounds, an improved potency of about 17-fold was observed for two derivatives. Detailed mechanistic studies on these structures revealed a competitive inhibition model, with a K(i)=27 nM, which makes these compounds some of the most potent small molecule, non-peptidic BoNT/A LC inhibitors reported to date. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Synthesis of[11C]LY186126, an inhibitor of phosphodiesterase

    International Nuclear Information System (INIS)

    Prenant, C.; Crouzel, C.; Comar, D.; Robertson, D.W.

    1992-01-01

    LY186126 [1,3-dihydro-1,3,3-trimethyl-5-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyriddazinyl)-2H-indol-2-one ], an analogue of the cardiotonic agent indolidan, is a potent, selective and competitive inhibitor of an isozymic form of cyclic AMP phosphodiesterase. LY186126 was labelled with carbon-11 to permit pharmacological studies in the dog myocardium by positron emission tomography. Alkylation with [ 11 C]methyl iodide of N-norLY186126 (LY-197055) allowed the production of 1.7 GBq (50mCi) of [ 11 C]LY-186126 in 40 min. The product, was purified by HPLC. (author)

  9. Synthesis and in Vitro and in Vivo Evaluation of Phosphoinositide-3-kinase Inhibitors.

    Science.gov (United States)

    Burger, Matthew T; Knapp, Mark; Wagman, Allan; Ni, Zhi-Jie; Hendrickson, Thomas; Atallah, Gordana; Zhang, Yanchen; Frazier, Kelly; Verhagen, Joelle; Pfister, Keith; Ng, Simon; Smith, Aaron; Bartulis, Sarah; Merrit, Hanne; Weismann, Marion; Xin, Xiaohua; Haznedar, Joshua; Voliva, Charles F; Iwanowicz, Ed; Pecchi, Sabina

    2011-01-13

    Phospoinositide-3-kinases (PI3K) are important oncology targets due to the deregulation of this signaling pathway in a wide variety of human cancers. A series of 2-morpholino, 4-substituted, 6-(3-hydroxyphenyl) pyrimidines have been reported as potent inhibitors of PI3Ks. Herein, we describe the structure-guided optimization of these pyrimidines with a focus on replacing the phenol moiety, while maintaining potent target inhibition and improving in vivo properties. A series of 2-morpholino, 4-substituted, 6-heterocyclic pyrimidines, which potently inhibit PI3K, were discovered. Within this series a compound, 17, was identified with suitable pharmacokinetic (PK) properties, which allowed for the establishment of a PI3K PK/pharmacodynamic-efficacy relationship as determined by in vivo inhibition of AKT(Ser473) phosphorylation and tumor growth inhibition in a mouse A2780 tumor xenograft model.

  10. Design, Synthesis and Biological Evaluation of Benzohydrazide Derivatives Containing Dihydropyrazoles as Potential EGFR Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Hai-Chao Wang

    2016-08-01

    Full Text Available A series of novel benzohydrazide derivatives containing dihydropyrazoles have been synthesized as potential epidermal growth factor receptor (EGFR kinase inhibitors and their biological activities as potential antiproliferative agents have been evaluated. Among these compounds, compound H20 exhibited the most potent antiproliferative activity against four cancer cell line variants (A549, MCF-7, HeLa, HepG2 with IC50 values of 0.46, 0.29, 0.15 and 0.21 μM respectively, which showed the most potent EGFR inhibition activities (IC50 = 0.08 μM for EGFR. Molecular modeling simulation studies were performed in order to predict the biological activity and activity relationship (SAR of these benzohydrazide derivatives. These results suggested that compound H20 may be a promising anticancer agent.

  11. Identification of Small Molecule Translesion Synthesis Inhibitors That Target the Rev1-CT/RIR Protein-Protein Interaction.

    Science.gov (United States)

    Sail, Vibhavari; Rizzo, Alessandro A; Chatterjee, Nimrat; Dash, Radha C; Ozen, Zuleyha; Walker, Graham C; Korzhnev, Dmitry M; Hadden, M Kyle

    2017-07-21

    Translesion synthesis (TLS) is an important mechanism through which proliferating cells tolerate DNA damage during replication. The mutagenic Rev1/Polζ-dependent branch of TLS helps cancer cells survive first-line genotoxic chemotherapy and introduces mutations that can contribute to the acquired resistance so often observed with standard anticancer regimens. As such, inhibition of Rev1/Polζ-dependent TLS has recently emerged as a strategy to enhance the efficacy of first-line chemotherapy and reduce the acquisition of chemoresistance by decreasing tumor mutation rate. The TLS DNA polymerase Rev1 serves as an integral scaffolding protein that mediates the assembly of the active multiprotein TLS complexes. Protein-protein interactions (PPIs) between the C-terminal domain of Rev1 (Rev1-CT) and the Rev1-interacting region (RIR) of other TLS DNA polymerases play an essential role in regulating TLS activity. To probe whether disrupting the Rev1-CT/RIR PPI is a valid approach for developing a new class of targeted anticancer agents, we designed a fluorescence polarization-based assay that was utilized in a pilot screen for small molecule inhibitors of this PPI. Two small molecule scaffolds that disrupt this interaction were identified, and secondary validation assays confirmed that compound 5 binds to Rev1-CT at the RIR interface. Finally, survival and mutagenesis assays in mouse embryonic fibroblasts and human fibrosarcoma HT1080 cells treated with cisplatin and ultraviolet light indicate that these compounds inhibit mutagenic Rev1/Polζ-dependent TLS in cells, validating the Rev1-CT/RIR PPI for future anticancer drug discovery and identifying the first small molecule inhibitors of TLS that target Rev1-CT.

  12. The MMP inhibitor (R)-2-(N-benzyl-4-(2-[18F]fluoroethoxy)phenylsulphonamido) -N-hydroxy-3-methylbutanamide: Improved precursor synthesis and fully automated radiosynthesis

    International Nuclear Information System (INIS)

    Wagner, Stefan; Faust, Andreas; Breyholz, Hans-Joerg; Schober, Otmar; Schaefers, Michael; Kopka, Klaus

    2011-01-01

    Summary: The CGS 25966 derivative (R)-2-(N-Benzyl-4-(2-[ 18 F]fluoroethoxy)phenyl-sulphonamido) -N-hydroxy-3-methylbutanamide [ 18 F]9 represents a very potent radiolabelled matrix metalloproteinase inhibitor. For first human PET studies it is mandatory to have a fully automated radiosynthesis and a straightforward precursor synthesis available. The realisation of both requirements is reported herein. In particular, the corresponding precursor 8 was obtained in a reliable 7 step synthesis with an overall chemical yield of 2.3%. Furthermore, the target compound [ 18 F]9 was prepared with a radiochemical yield of 14.8±3.9% (not corrected for decay).

  13. Chiral gold(I vs chiral silver complexes as catalysts for the enantioselective synthesis of the second generation GSK-hepatitis C virus inhibitor

    Directory of Open Access Journals (Sweden)

    María Martín-Rodríguez

    2011-07-01

    Full Text Available The synthesis of a GSK 2nd generation inhibitor of the hepatitis C virus, by enantioselective 1,3-dipolar cycloaddition between a leucine derived iminoester and tert-butyl acrylate, was studied. The comparison between silver(I and gold(I catalysts in this reaction was established by working with chiral phosphoramidites or with chiral BINAP. The best reaction conditions were used for the total synthesis of the hepatitis C virus inhibitor by a four step procedure affording this product in 99% ee and in 63% overall yield. The origin of the enantioselectivity of the chiral gold(I catalyst was justified according to DFT calculations, the stabilizing coulombic interaction between the nitrogen atom of the thiazole moiety and one of the gold atoms being crucial.

  14. Synthesis and Biological Evaluation of Benzochromenopyrimidinones as Cholinesterase Inhibitors and Potent Antioxidant, Non-Hepatotoxic Agents for Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Youssef Dgachi

    2016-05-01

    Full Text Available We report herein the straightforward two-step synthesis and biological assessment of novel racemic benzochromenopyrimidinones as non-hepatotoxic, acetylcholinesterase inhibitors with antioxidative properties. Among them, compound 3Bb displayed a mixed-type inhibition of human acetylcholinesterase (IC50 = 1.28 ± 0.03 μM, good antioxidant activity, and also proved to be non-hepatotoxic on human HepG2 cell line.

  15. Inhibitors of poly (ADP-ribose) synthesis inhibit the two types of repair of potentially lethal damage

    International Nuclear Information System (INIS)

    Utsumi, Hiroshi; Elkind, M.M.

    1994-01-01

    The purpose of this study was to examine whether 3-amino-benzamide (3ABA), an inhibitor of poly (ADP-ribose) synthesis, inhibits the two types of potentially lethal damage (PLD) repair, termed slow and fast. The fast-type PLD repair was measured by the decrease in survival of V79 Chinese hamster cells by postirradiation treatment with 3ABA. The slow-type PLD repair was measured by the increase in survival by posttreatment with conditioned medium (CM), which became conditioned by growing a crowed culture of cells and supports the slow-type PLD repair. Up to 1 mM 3-ABA inhibited the slow type repair; at doses of 2 mM and above, it inhibited the fast type of PLD repair. There are quantitative differences in cellular effects of 3ABA dependent on concentration. Poly (ADP-ribose) appears to play an important role in the PLD repairs and has little effect on the repair of sublethal damage. 10 refs., 2 figs

  16. Hybrid Pharmacophoric Approach in the Design and Synthesis of Coumarin Linked Pyrazolinyl as Urease Inhibitors, Kinetic Mechanism and Molecular Docking.

    Science.gov (United States)

    Saeed, Aamer; Mahesar, Parvez Ali; Channar, Pervaiz Ali; Larik, Fayaz Ali; Abbas, Qamar; Hassan, Mubashir; Raza, Hussain; Seo, Sung-Yum

    2017-08-01

    The current research article reports the synthesis of coumarinyl pyrazolinyl thioamide derivatives and their biological activity as inhibitors of jack bean urease. The coumarinyl pyrazolinyl thioamides were synthesized by reacting thiosemicarbazide with newly synthesized chalcones to afford the products in good yields and the synthesized compounds were purified by recrystallization. Coumarinyl pyrazolinyl thioamide derivatives 5a - 5q showed significant activity against Urease enzyme and also exhibited good antioxidant potential. The compound 3-(2-oxo-2H-chromen-3-yl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide (5n) was found to be superior agent in the series with an IC 50  = 0.358 ± 0.017 μm compared to standard thiourea with an IC 50  = 4720 ± 174 μm. To undermine the binding mode of inhibition kinetic studies were performed for most potent derivative and it was found that compound 5n inhibits urease enzyme by non-competitive mode of inhibition. Molecular docking studies were carried out to delineate the binding affinity of the synthesized derivatives. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  17. Synthesis and Docking Studies of 2,4,6-Trihydroxy-3-Geranylacetophenone Analogs as Potential Lipoxygenase Inhibitor

    Directory of Open Access Journals (Sweden)

    Chean Hui Ng

    2014-08-01

    Full Text Available The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs and aromatic groups could significantly affect the enzymatic activity.

  18. Effects of the chitin synthesis inhibitor buprofezin on survival and development of immatures of Chrysoperla rufilabris (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Liu, T X; Chen, T Y

    2000-04-01

    Effects of buprofezin (Applaud), a chitin synthesis inhibitor, on survival and development of eggs, three instars, and pupae of Chrysoperla rufilabris (Burmeister) were determined in the laboratory. Buprofezin at three tested concentrations (100, 500, and 1,000 mg [AI]/liter) did not affect the viability and development of eggs when the eggs were treated, or third instars and pupae when those stages were treated. Although the degree of effects by buprofezin on larvae varied with instar, buprofezin at the higher concentrations (500 and 1,000 mg [AI]/liter) reduced survival rates 17-47% and prolonged the overall development from first instars to adult emergence by 2 or 3 d when first instars were treated, indicating that the first instar is the most vulnerable stage. When second instars were treated, the survival of C. rufilabris from second instars to pupae was not significantly affected. However, the developmental time from second instar to adult emergence was longer in the treatments with the highest concentration (1,000 mg [AI]/liter) than that with the lowest concentration (100 mg [AI]/liter). The compatibility of buprofezin with natural enemies in integrated pest management programs is discussed.

  19. Synthesis of Sulochrin-125I and Its Binding Affinity as α-Glucosidase Inhibitor using Radioligand Binding Assay (RBA Method

    Directory of Open Access Journals (Sweden)

    W. Lestari

    2014-04-01

    Full Text Available Most of diabetics patients have type 2 diabetes mellitus or non insulin dependent diabetes mellitus. Treatment type 2 diabetes mellitus can be done by inhibiting α-glucosidase enzyme which converts carbohydrates into glucose. Sulochrin is one of the potential compounds which can inhibit the function of α-glucosidase enzyme. This study was carried out to obtain data of sulochrin binding with α-glucosidase enzyme as α-glucosidase inhibitor using Radioligand Binding Assay (RBA method. Primary reagent required in RBA method is labeled radioactive ligand (radioligand. In this study, the radioligand was sulochrin-125I and prior to sulochrin-125I synthesis, the sulochrin-I was synthesized. Sulochrin-I and sulochrin-125I were synthesized and their bindings were studied using Radioligand Binding Assay method. Sulochrin-I was synthesized with molecular formula C17H15O7I and molecular weight 457.9940. Sulochrin-125I was synthesized from sulochrin-I by isotope exchange method. From the RBA method, dissociation constant (Kd and maximum binding (Bmax were obtained 26.316 nM and Bmax 9.302 nM respectively. This low Kd indicated that sulochrin was can bind to α-glucosidase

  20. Bringing research into a first semester organic chemistry laboratory with the multistep synthesis of carbohydrate-based HIV inhibitor mimics.

    Science.gov (United States)

    Pontrello, Jason K

    2015-01-01

    Benefits of incorporating research experiences into laboratory courses have been well documented, yet examples of research projects designed for the first semester introductory organic chemistry lab course are extremely rare. To address this deficiency, a Carbohydrate-Based human immunodeficiency virus (HIV) Inhibitor project consisting of a synthetic scheme of four reactions was developed for and implemented in the first semester organic lab. Students carried out the synthetic reactions during the last 6 of 10 total labs in the course, generating carbohydrate-based dimeric target molecules modeled after published dimers with application in HIV therapy. The project was designed to provide a research experience through use of literature procedures for reactions performed, exploration of variation in linker length in the target structure, and synthesis of compounds not previously reported in the scientific literature. Project assessment revealed strong student support, indicating enhanced engagement and interest in the course as a direct result of the use of scientific literature and the applications of the synthesized carbohydrate-based molecules. Regardless of discussed challenges in designing a research project for the first semester lab course, the finding from data analysis that a project implemented in the first semester lab had significantly greater student impact than a second semester project should provide motivation for development of additional research projects for a first semester organic course. © 2015 The International Union of Biochemistry and Molecular Biology.

  1. Synthesis of 14C- and 3H-labeled fluoxetine, a selective serotonin uptake inhibitor

    International Nuclear Information System (INIS)

    Robertson, D.W.; Krushinski, J.H.; Wong, D.T.; Kau, D.

    1987-01-01

    Fluoxetine (N-methyl-γ-(4-(trifluoromethyl)phenoxy) benzenepropanamine) is a potent, highly selective serotonin uptake inhibitor that is useful in treating a variety of major psychiatric derangements. We have synthesized this compound in 14 C- and 3 H-labeled forms. The tritium label was introduced in the final step by catalytic dehalogenation of the brominated fluoxetine precursor. Reaction conditions could be controlled such that catalytic hydrogenolysis of the labile C-O benzylic bond was minimized. Following HPLC purification, [ 3 H]-fluoxetine was obtained in a state of high radiochemical purity (98%) and specific activity (20.4 Ci/mmol). The 14 C-label was introduced in the final step via a nucleophilic aromatic substitution reaction between the sodium salt of α-(2-(methylamino)ethyl)benzenemethanol and uniformly ring-labeled p-chlorobenzotrifluoride. Following purification by flash chromatography, [ 14 C]-fluoxetine was obtained in 98.3% radiochemical purity with a specific activity of 5.52 mCi/mmol. (author)

  2. Synthesis of giant globular multivalent glycofullerenes as potent inhibitors in a model of Ebola virus infection

    Science.gov (United States)

    Muñoz, Antonio; Sigwalt, David; Illescas, Beatriz M.; Luczkowiak, Joanna; Rodríguez-Pérez, Laura; Nierengarten, Iwona; Holler, Michel; Remy, Jean-Serge; Buffet, Kevin; Vincent, Stéphane P.; Rojo, Javier; Delgado, Rafael; Nierengarten, Jean-François; Martín, Nazario

    2016-01-01

    The use of multivalent carbohydrate compounds to block cell-surface lectin receptors is a promising strategy to inhibit the entry of pathogens into cells and could lead to the discovery of novel antiviral agents. One of the main problems with this approach, however, is that it is difficult to make compounds of an adequate size and multivalency to mimic natural systems such as viruses. Hexakis adducts of [60]fullerene are useful building blocks in this regard because they maintain a globular shape at the same time as allowing control over the size and multivalency. Here we report water-soluble tridecafullerenes decorated with 120 peripheral carbohydrate subunits, so-called ‘superballs’, that can be synthesized efficiently from hexakis adducts of [60]fullerene in one step by using copper-catalysed azide-alkyne cycloaddition click chemistry. Infection assays show that these superballs are potent inhibitors of cell infection by an artificial Ebola virus with half-maximum inhibitory concentrations in the subnanomolar range.

  3. Synthesis of organic nitrates of luteolin as a novel class of potent aldose reductase inhibitors.

    Science.gov (United States)

    Wang, Qi-Qin; Cheng, Ning; Zheng, Xiao-Wei; Peng, Sheng-Ming; Zou, Xiao-Qing

    2013-07-15

    Aldose reductase (AR) plays an important role in the design of drugs that prevent and treat diabetic complications. Aldose reductase inhibitors (ARIs) have received significant attentions as potent therapeutic drugs. Based on combination principles, three series of luteolin derivatives were synthesised and evaluated for their AR inhibitory activity and nitric oxide (NO)-releasing capacity in vitro. Eighteen compounds were found to be potent ARIs with IC50 values ranging from (0.099±0.008) μM to (2.833±0.102) μM. O(7)-Nitrooxyethyl-O(3'),O(4')-ethylidene luteolin (La1) showed the most potent AR inhibitory activity [IC50=(0.099±0.008) μM]. All organic nitrate derivatives released low concentrations of NO in the presence of l-cysteine. Structure-activity relationship studies suggested that introduction of an NO donor, protection of the catechol structure, and the ether chain of a 2-carbon spacer as a coupling chain on the luteolin scaffold all help increase the AR inhibitory activity of the resulting compound. This class of NO-donor luteolin derivatives as efficient ARIs offer a new concept for the development and design of new drug for preventive and therapeutic drugs for diabetic complications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. New coumarin derivatives: design, synthesis and use as inhibitors of hMAO.

    Science.gov (United States)

    He, Xu; Chen, Yan-Yan; Shi, Jing-Bo; Tang, Wen-Jiang; Pan, Zhi-Xiang; Dong, Zhi-Qiang; Song, Bao-An; Li, Jun; Liu, Xin-Hua

    2014-07-15

    A series new 2H-chromene-3-carboxamides (4a-4i) and S-2H-chromene-3-carbothioates (5j-5t) were synthesized and evaluated as monoamine oxidase A and B inhibitors. Among them, compound 5k (IC50=0.21μM, IC50 iproniazid=7.65μM) showed the most activity and higher MAO-B selectivity (189.2-fold vs 1-fold) with respect to the MAO-A isoform. The need to clarify at a 3D level some important molecular aspects of discussed SAR, we undertaked a number of docking simulations to better assess. The steric effect was analyzed interms of both posing and scoring by investigating the nature of the binding interactions. The docking results of active compound 5k with hMAO-B complex indicated that conserved residue ILE 199 was important for ligand binding via Sigma-Pi interaction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Synthesis and Experimental Validation of New PDI Inhibitors with Antiproliferative Activity

    Directory of Open Access Journals (Sweden)

    Mariateresa Badolato

    2017-01-01

    Full Text Available Protein disulfide isomerase (PDI is a member of the thioredoxin superfamily of redox enzymes. PDI is a multifunctional protein that catalyzes disulfide bond formation, cleavage, and rearrangement in unfolded or misfolded proteins and functions as a chaperone in the endoplasmic reticulum. Besides acting as a protein folding catalyst, several evidences have suggested that PDI can bind small molecules containing, for example, a phenolic structure, which includes the estrogenic one. Increasing studies indicate that PDI is involved in both physiology and pathophysiology of cells and tissues and is involved in the survival and proliferation of different cancers. Propionic acid carbamoyl methyl amides (PACMAs showed anticancer activity in human ovarian cancer, both in vitro and in vivo, by inhibiting PDI. The inhibition of PDI’s activity may have a therapeutic role, in various diseases, including cancer. In the present study, we designed and synthesized a diversified small library of compounds with the aim of identifying a new class of PDI inhibitors. Most of synthesized compounds showed a good inhibitory potency against PDI and particularly 4-methyl substituted 2,6-di-tert-butylphenol derivatives (8–10 presented an antiproliferative activity in a wide panel of human cancer cell lines, including ovarian ones.

  6. Synthesis and in vitro study of benzofuran hydrazone derivatives as novel alpha-amylase inhibitor.

    Science.gov (United States)

    Taha, Muhammad; Shah, Syed Adnan Ali; Imran, Syahrul; Afifi, Muhammad; Chigurupati, Sridevi; Selvaraj, Manikandan; Rahim, Fazal; Ullah, Hayat; Zaman, Khalid; Vijayabalan, Shantini

    2017-12-01

    The α-amylase acts as attractive target to treat type-2 diabetes mellitus. Therefore in discovering a small molecule as α-amylase inhibitor, we have synthesized benzofuran carbohydrazide analogs (1-25), characterized through different spectroscopic techniques such as 1 HNMR and EI-MS. All screened analog shows good α-amylase inhibitory potentials with IC 50 value ranging between 1.078±0.19 and 2.926±0.05µM when compared with acarbose having IC 50 =0.62±0.22µM. Only nine analogs among the series such as analogs 3, 5, 7, 8, 10, 12, 21, 23 and 24 exhibit good inhibitory potential with IC 50 values 1.644±0.128, 1.078±0.19, 1.245±0.25, 1.843±0.19, 1.350±0.24, 1.629±0.015, 1.353±0.232, 1.359±0.119 and 1.488±0.07µM when compare with standard drug acarbose. All other analogs showed good to moderate α-amylase inhibitory potentials. The SAR study was conducted on the basis of substituent difference at the phenyl ring. The binding interaction between analogs and active site of enzyme was confirmed by docking studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. SYNTHESIS AND EVALUATION OF NEW PHTHALAZINE SUBSTITUTED β-LACTAM DERIVATIVES AS CARBONIC ANHYDRASE INHIBITORS.

    Science.gov (United States)

    Berber, Nurcan; Arslan, Mustafa; Bilen, Çiğdem; Sackes, Zübeyde; Gençer, Nahit; Arslan, Oktay

    2015-01-01

    A new series of phthalazine substituted β-lactam derivatives were synthesized and their inhibitory effects on the activity of purified human carbonic anhydrase (hCA I and II) were evaluated. 2H-Indazolo[2,1-b]phthala- zine-trione derivative was prepared with 4-nitrobenzaldehyde, dimedone, and phthalhydrazide in the presence of TFA in DMF, and the nitro group was reduced to 13-(4-aminophenyl)-3,3-dimethyl-3,4-dihydro- 2H-indazolo[1,2-b]phthalazine-1,6,11(13H)-trione with SnCl2 · 2H2O. The reduced compound was re- acted with different aromatic aldehydes, and phthalazine substituted imines were synthesized. The imine compounds undergo (2+2) cycloaddition reactions with ketenes to produce 2H-indazolo[2,1-b]phthala-zine-trione substituted β-lactam derivatives. The β-lactam compounds were tested as inhibitors of the CA isoenzyme activity. The results showed that all the synthesized compounds inhibited the CA isoenzyme activity. 1-(4-(3,3-dimethyl- 1,6,1 1-trioxo-2,3,4,6,11,13-hexahydro-1H-indazolo[1,2-b]phthalazin-13- yl)phenyl)-2-oxo-4-p-tolylazetidin-3-yl acetate (IC50 = 6.97 µM for hCA I and 8.48 µM for hCA II) had the most inhibitory effect.

  8. Synthesis and antifungal activity of nicotinamide derivatives as succinate dehydrogenase inhibitors.

    Science.gov (United States)

    Ye, Yong-Hao; Ma, Liang; Dai, Zhi-Cheng; Xiao, Yu; Zhang, Ying-Ying; Li, Dong-Dong; Wang, Jian-Xin; Zhu, Hai-Liang

    2014-05-07

    Thirty-eight nicotinamide derivatives were designed and synthesized as potential succinate dehydrogenase inhibitors (SDHI) and precisely characterized by (1)H NMR, ESI-MS, and elemental analysis. The compounds were evaluated against two phytopathogenic fungi, Rhizoctonia solani and Sclerotinia sclerotiorum, by mycelia growth inhibition assay in vitro. Most of the compounds displayed moderate activity, in which, 3a-17 exhibited the most potent antifungal activity against R. solani and S. sclerotiorum with IC50 values of 15.8 and 20.3 μM, respectively, comparable to those of the commonly used fungicides boscalid and carbendazim. The structure-activity relationship (SAR) of nicotinamide derivatives demonstrated that the meta-position of aniline was a key position contributing to the antifungal activity. Inhibition activities against two fungal SDHs were tested and achieved the same tendency with the data acquired from in vitro antifungal assay. Significantly, 3a-17 was demonstrated to successfully suppress disease development in S. sclerotiorum infected cole in vivo. In the molecular docking simulation, sulfur and chlorine of 3a-17 were bound with PHE291 and PRO150 of the SDH homology model, respectively, which could explain the probable mechanism of action between the inhibitory and target protein.

  9. Identification of anthranilamide derivatives as potential factor Xa inhibitors: drug design, synthesis and biological evaluation.

    Science.gov (United States)

    Xing, Junhao; Yang, Lingyun; Li, Hui; Li, Qing; Zhao, Leilei; Wang, Xinning; Zhang, Yuan; Zhou, Muxing; Zhou, Jinpei; Zhang, Huibin

    2015-05-05

    The coagulation enzyme factor Xa (fXa) plays a crucial role in the blood coagulation cascade. In this study, three-dimensional fragment based drug design (FBDD) combined with structure-based pharmacophore (SBP) model and structural consensus docking were employed to identify novel fXa inhibitors. After a multi-stage virtual screening (VS) workflow, two hit compounds 3780 and 319 having persistent high performance were identified. Then, these two hit compounds and several analogs were synthesized and screened for in-vitro inhibition of fXa. The experimental data showed that most of the designed compounds displayed significant in vitro potency against fXa. Among them, compound 9b displayed the greatest in vitro potency against fXa with the IC50 value of 23 nM and excellent selectivity versus thrombin (IC50 = 40 μM). Moreover, the prolongation of the prothrombin time (PT) was measured for compound 9b to evaluate its in vitro anticoagulant activity. As a result, compound 9b exhibited pronounced anticoagulant activity with the 2 × PT value of 8.7 μM. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  10. Synthesis of Triphenylethylene Bisphenols as Aromatase Inhibitors That Also Modulate Estrogen Receptors.

    Science.gov (United States)

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C; O'Neill, Elizaveta; Yu, Ge; Flockhart, David A; Cushman, Mark

    2016-01-14

    A series of triphenylethylene bisphenol analogues of the selective estrogen receptor modulator (SERM) tamoxifen were synthesized and evaluated for their abilities to inhibit aromatase, bind to estrogen receptor α (ER-α) and estrogen receptor β (ER-β), and antagonize the activity of β-estradiol in MCF-7 human breast cancer cells. The long-range goal has been to create dual aromatase inhibitor (AI)/selective estrogen receptor modulators (SERMs). The hypothesis is that in normal tissue the estrogenic SERM activity of a dual AI/SERM could attenuate the undesired effects stemming from global estrogen depletion caused by the AI activity of a dual AI/SERM, while in breast cancer tissue the antiestrogenic SERM activity of a dual AI/SERM could act synergistically with AI activity to enhance the antiproliferative effect. The potent aromatase inhibitory activities and high ER-α and ER-β binding affinities of several of the resulting analogues, together with the facts that they antagonize β-estradiol in a functional assay in MCF-7 human breast cancer cells and they have no E/Z isomers, support their further development in order to obtain dual AI/SERM agents for breast cancer treatment.

  11. Synthesis of novel disulfide and sulfone hybrid scaffolds as potent β-glucuronidase inhibitor.

    Science.gov (United States)

    Taha, Muhammad; Ismail, Nor Hadiani; Imran, Syahrul; Wadood, Abdul; Rahim, Fazal; Al Muqarrabin, Laode Muhammad Ramadhan; Zaki, Hamizah Mohd; Ahmat, Norizan; Nasir, Abdul; Khan, Fahad

    2016-10-01

    Novel series of disulfide and sulfone hybrid analogs (1-20) were synthesized and characterized through EI-MS and (1)H NMR and evaluated for β-glucuronidase inhibitory potential. All synthesized analogs except 13 and 15 showed excellent β-glucuronidase inhibitory potential with IC50 value ranging in between 2.20-88.16μM as compared to standard d-saccharic acid 1,4 lactone (48.4±1.25μM). Analogs 19, 16, 4, 1, 17, 6, 10, 3, 18, 2, 11, 14 and 5 showed many fold potent activity against β-glucuronidase inhibitor. Structure activity relationship showed that substitution of electron withdrawing groups at ortho as well as para position on phenyl ring increase potency. Electron withdrawing groups at meta position on phenyl ring showed slightly low potency as compared to ortho and para position. The binding interactions were confirmed through molecular docking studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. 6-Nitrobenzimidazole derivatives: potential phosphodiesterase inhibitors: synthesis and structure-activity relationship.

    Science.gov (United States)

    Khan, K M; Shah, Zarbad; Ahmad, V U; Ambreen, N; Khan, M; Taha, M; Rahim, F; Noreen, S; Perveen, S; Choudhary, M I; Voelter, W

    2012-02-15

    6-Nitrobenzimidazole derivatives (1-30) synthesized and their phosphodiesterase inhibitory activities determined. Out of thirty tested compounds, ten showed a varying degrees of phosphodiesterase inhibition with IC(50) values between 1.5±0.043 and 294.0±16.7 μM. Compounds 30 (IC(50)=1.5±0.043 μM), 1 (IC(50)=2.4±0.049 μM), 11 (IC(50)=5.7±0.113 μM), 13 (IC(50)=6.4±0.148 μM), 14 (IC(50)=10.5±0.51 μM), 9 (IC(50)=11.49±0.08 μM), 3 (IC(50)=63.1±1.48 μM), 10 (IC(50)=120.0±4.47 μM), and 6 (IC(50)=153.2±5.6 μM) showed excellent phosphodiesterase inhibitory activity, much superior to the standard EDTA (IC(50)=274±0.007 μM), and thus are potential molecules for the development of a new class of phosphodiesterase inhibitors. A structure-activity relationship is evaluated. All compounds are characterized by spectroscopic parameters. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Synthesis of a Vpr-Binding Derivative for Use as a Novel HIV-1 Inhibitor.

    Science.gov (United States)

    Hagiwara, Kyoji; Ishii, Hideki; Murakami, Tomoyuki; Takeshima, Shin-nosuke; Chutiwitoonchai, Nopporn; Kodama, Eiichi N; Kawaji, Kumi; Kondoh, Yasumitsu; Honda, Kaori; Osada, Hiroyuki; Tsunetsugu-Yokota, Yasuko; Suzuki, Masaaki; Aida, Yoko

    2015-01-01

    The emergence of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus type 1 (HIV-1) therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. We previously identified a potential parent compound, hematoxylin, which suppresses the nuclear import of HIV-1 via the Vpr-importin α interaction and inhibits HIV-1 replication in a Vpr-dependent manner by blocking nuclear import of the pre-integration complex. However, it was unstable. Here, we synthesized a stable derivative of hematoxylin that bound specifically and stably to Vpr and inhibited HIV-1 replication in macrophages. Furthermore, like hematoxylin, the derivative inhibited nuclear import of Vpr in an in vitro nuclear import assay, but had no effect on Vpr-induced G2/M phase cell cycle arrest or caspase activity. Interestingly, this derivative bound strongly to amino acid residues 54-74 within the C-terminal α-helical domain (αH3) of Vpr. These residues are highly conserved among different HIV strains, indicating that this region is a potential target for drug-resistant HIV-1 infection. Thus, we succeeded in developing a stable hematoxylin derivative that bound directly to Vpr, suggesting that specific inhibitors of the interaction between cells and viral accessory proteins may provide a new strategy for the treatment of HIV-1 infection.

  14. Synthesis of a Vpr-Binding Derivative for Use as a Novel HIV-1 Inhibitor.

    Directory of Open Access Journals (Sweden)

    Kyoji Hagiwara

    Full Text Available The emergence of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus type 1 (HIV-1 therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. We previously identified a potential parent compound, hematoxylin, which suppresses the nuclear import of HIV-1 via the Vpr-importin α interaction and inhibits HIV-1 replication in a Vpr-dependent manner by blocking nuclear import of the pre-integration complex. However, it was unstable. Here, we synthesized a stable derivative of hematoxylin that bound specifically and stably to Vpr and inhibited HIV-1 replication in macrophages. Furthermore, like hematoxylin, the derivative inhibited nuclear import of Vpr in an in vitro nuclear import assay, but had no effect on Vpr-induced G2/M phase cell cycle arrest or caspase activity. Interestingly, this derivative bound strongly to amino acid residues 54-74 within the C-terminal α-helical domain (αH3 of Vpr. These residues are highly conserved among different HIV strains, indicating that this region is a potential target for drug-resistant HIV-1 infection. Thus, we succeeded in developing a stable hematoxylin derivative that bound directly to Vpr, suggesting that specific inhibitors of the interaction between cells and viral accessory proteins may provide a new strategy for the treatment of HIV-1 infection.

  15. Dual functional cholinesterase and MAO inhibitors for the treatment of Alzheimer's disease: synthesis, pharmacological analysis and molecular modeling of homoisoflavonoid derivatives.

    Science.gov (United States)

    Wang, Yali; Sun, Yang; Guo, Yueyan; Wang, Zechen; Huang, Ling; Li, Xingshu

    2016-01-01

    Because of the complexity of Alzheimer's disease (AD), the multi-target-directed ligand (MTDL) strategy is expected to provide superior effects for the treatment of AD, instead of the classic one-drug-one-target strategy. In this context, we focused on the design, synthesis and evaluation of homoisoflavonoid derivatives as dual acetyl cholinesterase (AChE) and monoamine oxidase (MAO-B) inhibitors. Among all the synthesized compounds, compound 10 provided a desired balance of AChE and hMAO-B inhibition activities, with IC50 value of 3.94 and 3.44 μM, respectively. Further studies revealed that compound 10 was a mixed-type inhibitor of AChE and an irreversible inhibitor of hMAO-B, which was also confirmed by molecular modeling studies. Taken together, the data indicated that 10 was a promising dual functional agent for the treatment of AD.

  16. Design, synthesis, and biological evaluation of prenylated chalcones as 5-LOX inhibitors.

    Science.gov (United States)

    Reddy, Nimmanapalli P; Aparoy, Polamarasetty; Reddy, T Chandra Mohan; Achari, Chandrani; Sridhar, P Ramu; Reddanna, Pallu

    2010-08-15

    Ten novel mono- and di-O-prenylated chalcone derivatives were designed on the basis of a homology derived molecular model of 5-lipoxygenase (5-LOX). The compounds were docked into 5-LOX active site and the binding characteristics were quantified using LUDI. To verify our theoretical assumption, the molecules were synthesized and tested for their 5-LOX inhibitory activities. The synthesis was carried out by Claisen-Schmidt condensation reaction of mono- and di-O-prenylated acetophenones with appropriate aldehydes. 5-LOX in vitro inhibition assay showed higher potency of di-O-prenylated chalcones than their mono-O-prenylated chalcone analogs. Compound 5e exhibited good inhibition with an IC(50) at 4 microM. The overall trend for the binding energies calculated and LUDI score was in good qualitative agreement with the experimental data. Further, the compound 5e showed potent anti-proliferative effects (GI(50) at 9 microM) on breast cancer cell line, MCF-7. Copyright 2010 Elsevier Ltd. All rights reserved.

  17. New anthrarobin acyl derivatives as butyrylcholinesterase inhibitors: synthesis, in vitro and in silico studies

    Directory of Open Access Journals (Sweden)

    Mehreen Lateef

    2017-07-01

    Full Text Available To treat Alzheimer's disease (AD, the available candidates are effective only against mild AD or have side effects. So, a study was planned to synthesis new candidates that may have good potential to treat AD. A series of new anthrarobin acyl derivatives (2–8 were synthesized by the reaction of anthrarobin (1 and acetic anhydride/acyl chlorides. The product were characterized by 1H NMR and EI-MS, and evaluated for butyrylcholinesterase (BuChE inhibition activity. Compounds 5 and 4 showed notable BuChE inhibitory potential with IC50 5.3 ± 1.23 and 17.2 ± 0.47 μM, respectively when compared with the standard eserine (IC50 7.8 ± 0.27 μM, compound 5 showed potent BuChE inhibition potential than the standard eserine. The active compounds 5 and 4 have acyl groups at 2-OH and 10-OH positions which may be responsible for inhibitory potential as this orientation is absent in other products. In silico studies of 5 and 4 products revealed the high inhibitory potential due to stable binding of ligand with the BuChE active sites with docking energy score −18.8779 kcal/mol and −23.1159 kcal/mol, respectively. Subsequently, compound 5 that have potent BuChE inhibitory activity could be the potential candidate for drug development for Alzheimer’s disease.

  18. Design, Synthesis, and Biological Evaluation of Vanillin Hydroxamic Acid Derivatives as Novel Peptide Deformylase Inhibitors.

    Science.gov (United States)

    Gao, Jian; Qiu, Shengzhi; Liang, Li; Hao, Zhixiang; Zhou, Qianqian; Wang, Fanfan; Mou, Jie; Lin, Qisi

    2018-01-01

    Infectious disease is increasingly hampering human health, which challenge the discovery of new antibacterial target. Peptide deformylase (PDF), a metalloenzyme responsible for catalyzing the removal of the N-formyl group from nascent proteins, was considered as an important target in antibacterial drug discovery. Reported here are the design, synthesis and biological evaluation of vanillin hydroxamic acid derivatives. Analysis of the structure-activity relationships lead to the discovery of compound 8, which exhibits promising antibacterial activity against Escherichia coli, Staphylococcus aureus, Aspergillus oryzae, and Aspergillus foetidus with the MIC value of 0.32 µg/ml, 0.32 µg/ml, 0.16 µg/ml and 0.16 µg/ml, respectively. Furthermore, molecular docking study was applied to elucidate binding interaction between compound 8 and PDF, which indicate that compound 8 not only shares the same binding pocket with actinonin, but also has a similar binding pattern. In silico pharmacokinetic and toxicity prediction studies also suggested that compound 8 has a relatively high drug score of 0.80, and has no risk of toxicity. Compound 8 might represent a promising scaffold for the further development of novel antibacterial drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Synthesis and biological evaluation of novel 5-hydroxylaminoisoxazole derivatives as lipoxygenase inhibitors and metabolism enhancing agents.

    Science.gov (United States)

    Averina, Elena B; Vasilenko, Dmitry A; Gracheva, Yulia A; Grishin, Yuri K; Radchenko, Eugene V; Burmistrov, Vladimir V; Butov, Gennady M; Neganova, Margarita E; Serkova, Tatyana P; Redkozubova, Olga M; Shevtsova, Elena F; Milaeva, Elena R; Kuznetsova, Tamara S; Zefirov, Nikolay S

    2016-02-15

    A versatile synthesis of novel 5-hydroxylaminoisoxazoles bearing adamantane moieties has been accomplished using the heterocyclization reactions of readily available unsaturated esters by the treatment with tetranitromethane in the presence of triethylamine and subsequent reduction of resulting 5-nitroisoxazoles by SnCl2 with the participation of THF. A number of obtained isoxazole derivatives were evaluated for their antioxidative activity, inhibition of lipoxygenases and impact on the rat liver mitochondria. The majority of tested compounds demonstrated moderate antiradical activity in DPPH test (up to EC50 16μM). The same compounds strongly inhibited soybean lipoxygenase (up to IC50 0.4μM) and Fe(2+)- and Fe(3+)-induced lipid peroxidation (LP) of rat brain cortex homogenate (up to IC50 0.3μM). All tested isoxazole derivatives promoted the phosphorylating respiratory activity simultaneously with maximal stimulated respiratory activity of mitochondria and do not reveal any toxicity towards the primary culture of rat cortex neurons. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Activity of a lipid synthesis inhibitor (spiromesifen in Culiseta longiareolata (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Hayette Bouabida

    2017-12-01

    Full Text Available Objective: To evaluate the activity of spiromesifen against the most abundant and investigated mosquito species, Culiseta longiareolata Aitken, 1954 (Diptera, Culicidae. Methods: Culiseta longiareolata larvae were collected from untreated areas located at Tébessa (Northeast Algeria. A commercial formulation of spiromesifen (Oberon® 240 SC was tested at different concentrations ranging between 238 and 1428 μg/L on newly molted fourth-instar larvae under standard laboratory conditions according to Word Health Organization recommendations. The effects were examined on the mortality, the morphometric measurements, two biomarkers (catalase and malondialdehyde, and the biochemical composition of larvae, respectively. Results: The compound exhibited insecticidal activity. Moreover, it disturbed growth and several morphological aberrations were observed. It also affected body volume, biomarkers and contents of carbohydrates, lipids and proteins. A marked effect on lipids and malondialdehyde was noted, confirming its primary mode of action on lipid synthesis. Conclusions: Spiromesifen appears less potent than other insecticides tested such as the insect growth disruptors. Keywords: Culiseta longiareolata, Spiromesifen, Toxicity, Biochemical composition, Biomarkers

  1. Rapid Assessment of Resistance to Antibiotic Inhibitors of Protein Synthesis in the Gram-Positive Pathogens, Enterococcus faecalis and Streptococcus pneumoniae, Based on Evaluation of the Lytic Response.

    Science.gov (United States)

    Otero, Fátima; Tamayo, María; Santiso, Rebeca; Gosálvez, Jaime; Bou, Germán; Fernández, José Luis

    2017-04-01

    A novel assay for rapid determination of resistance to antibiotic inhibitors of protein synthesis was developed for the gram-positive pathogens, Enterococcus faecalis and Streptococcus pneumoniae. To this purpose, a lytic response was obtained by a brief incubation with lysozyme or a mixture of lysozyme, Triton X-100, and EDTA for E. faecalis (n = 82) and S. pneumoniae (n = 51), respectively. Lysis was quantified by visualizing the released nucleoids. Antibiotic-susceptible bacteria treated with Clinical and Laboratory Standards Institute (CLSI) breakpoint doses of erythromycin, azithromycin, or doxycycline that inhibited protein synthesis demonstrated a large reduction of lysed cells with respect to the control, that is, without antibiotics. However, cell lysis prevention was much lower in nonsusceptible strains, with unsuccessful inhibition of protein synthesis. ROC analysis showed that a reduction value of ≥35.6% and ≥40.4% discriminates susceptible and nonsusceptible strains for erythromycin and for doxycycline, respectively, in E. faecalis, whereas ≥20.0% is adequate for both macrolides and doxycycline in S. pneumoniae. Resistant stains were identified in 90-120 min with sensitivity and specificity between 91.7% and 100%. This is a proof of concept that evaluation of the lytic response may be a rapid and efficient test for determination of resistance to antibiotic inhibitors of protein synthesis.

  2. Sirtuin 1 gene rs2273773 C >T single nucleotide polymorphism and ...

    African Journals Online (AJOL)

    Background: Sirtuin-1 (SIRT-1), a protein has been found to protect the cells against oxidative stress due to its deacetylase activity. In this investigation, we aimed to study SIRT-1 gene rs2273773 C >T single nucleotide polymorphism and markers of serum protein oxidation (protein carbonyl and sulfhydryl groups) in ...

  3. Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

    Directory of Open Access Journals (Sweden)

    Ken Shinmura

    2013-01-01

    Full Text Available The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

  4. Sirtuin 1 gene rs2273773 C>T single nucleotide polymorphism and ...

    African Journals Online (AJOL)

    Aida Abdeen Mahmoud

    2015-12-24

    Dec 24, 2015 ... Abstract Background: Sirtuin-1 (SIRT-1), a protein has been found to protect the cells against oxidative stress ... rs2273773 C > T SNP and serum markers of protein oxida- tion (protein ..... tance and pulmonary dynamic compliance. Treatment ... [4] Autiero I, Costantini S, Colonna G. Human sirt-1: molecular.

  5. Role of NAD+ and mitochondrial sirtuins in cardiac and renal diseases.

    Science.gov (United States)

    Hershberger, Kathleen A; Martin, Angelical S; Hirschey, Matthew D

    2017-04-01

    The coenzyme nicotinamide adenine dinucleotide (NAD + ) has key roles in the regulation of redox status and energy metabolism. NAD + depletion is emerging as a major contributor to the pathogenesis of cardiac and renal diseases and NAD + repletion strategies have shown therapeutic potential as a means to restore healthy metabolism and physiological function. The pleotropic roles of NAD + enable several possible avenues by which repletion of this coenzyme could have therapeutic efficacy. In particular, NAD + functions as a co-substrate in deacylation reactions carried out by the sirtuin family of enzymes. These NAD + -dependent deacylases control several aspects of metabolism and a wealth of data suggests that boosting sirtuin activity via NAD + supplementation might be a promising therapy for cardiac and renal pathologies. This Review summarizes the role of NAD + metabolism in the heart and kidney, and highlights the mitochondrial sirtuins as mediators of some of the beneficial effects of NAD + -boosting therapies in preclinical animal models. We surmise that modulating the NAD + -sirtuin axis is a clinically relevant approach to develop new therapies for cardiac and renal diseases.

  6. Knock-out of a mitochondrial sirtuin protects neurons from degeneration in Caenorhabditis elegans.

    Science.gov (United States)

    Sangaletti, Rachele; D'Amico, Massimo; Grant, Jeff; Della-Morte, David; Bianchi, Laura

    2017-08-01

    Sirtuins are NAD⁺-dependent deacetylases, lipoamidases, and ADP-ribosyltransferases that link cellular metabolism to multiple intracellular pathways that influence processes as diverse as cell survival, longevity, and cancer growth. Sirtuins influence the extent of neuronal death in stroke. However, different sirtuins appear to have opposite roles in neuronal protection. In Caenorhabditis elegans, we found that knock-out of mitochondrial sirtuin sir-2.3, homologous to mammalian SIRT4, is protective in both chemical ischemia and hyperactive channel induced necrosis. Furthermore, the protective effect of sir-2.3 knock-out is enhanced by block of glycolysis and eliminated by a null mutation in daf-16/FOXO transcription factor, supporting the involvement of the insulin/IGF pathway. However, data in Caenorhabditis elegans cell culture suggest that the effects of sir-2.3 knock-out act downstream of the DAF-2/IGF-1 receptor. Analysis of ROS in sir-2.3 knock-out reveals that ROS become elevated in this mutant under ischemic conditions in dietary deprivation (DD), but to a lesser extent than in wild type, suggesting more robust activation of a ROS scavenging system in this mutant in the absence of food. This work suggests a deleterious role of SIRT4 during ischemic processes in mammals that must be further investigated and reveals a novel pathway that can be targeted for the design of therapies aimed at protecting neurons from death in ischemic conditions.

  7. Chronic alcohol binging injures the liver and other organs by reducing NAD⁺ levels required for sirtuin's deacetylase activity.

    Science.gov (United States)

    French, Samuel W

    2016-04-01

    NAD(+) levels are markedly reduced when blood alcohol levels are high during binge drinking. This causes liver injury to occur because the enzymes that require NAD(+) as a cofactor such as the sirtuin de-acetylases cannot de-acetylate acetylated proteins such as acetylated histones. This prevents the epigenetic changes that regulate metabolic processes and which prevent organ injury such as fatty liver in response to alcohol abuse. Hyper acetylation of numerous regulatory proteins develops. Systemic multi-organ injury occurs when NAD(+) is reduced. For instance the Circadian clock is altered if NAD(+) is not available. Cell cycle arrest occurs due to up regulation of cell cycle inhibitors leading to DNA damage, mutations, apoptosis and tumorigenesis. NAD(+) is linked to aging in the regulation of telomere stability. NAD(+) is required for mitochondrial renewal. Alcohol dehydrogenase is present in every visceral organ in the body so that there is a systemic reduction of NAD(+) levels in all of these organs during binge drinking. Copyright © 2016. Published by Elsevier Inc.

  8. TNF-α protein synthesis inhibitor restores neuronal function and reverses cognitive deficits induced by chronic neuroinflammation

    Directory of Open Access Journals (Sweden)

    Belarbi Karim

    2012-01-01

    Full Text Available Abstract Background Chronic neuroinflammation is a hallmark of several neurological disorders associated with cognitive loss. Activated microglia and secreted factors such as tumor necrosis factor (TNF-α are key mediators of neuroinflammation and may contribute to neuronal dysfunction. Our study was aimed to evaluate the therapeutic potential of a novel analog of thalidomide, 3,6'-dithiothalidomide (DT, an agent with anti-TNF-α activity, in a model of chronic neuroinflammation. Methods Lipopolysaccharide or artificial cerebrospinal fluid was infused into the fourth ventricle of three-month-old rats for 28 days. Starting on day 29, animals received daily intraperitoneal injections of DT (56 mg/kg/day or vehicle for 14 days. Thereafter, cognitive function was assessed by novel object recognition, novel place recognition and Morris water maze, and animals were euthanized 25 min following water maze probe test evaluation. Results Chronic LPS-infusion was characterized by increased gene expression of the proinflammatory cytokines TNF-α and IL-1β in the hippocampus. Treatment with DT normalized TNF-α levels back to control levels but not IL-1β. Treatment with DT attenuated the expression of TLR2, TLR4, IRAK1 and Hmgb1, all genes involved in the TLR-mediated signaling pathway associated with classical microglia activation. However DT did not impact the numbers of MHC Class II immunoreactive cells. Chronic neuroinflammation impaired novel place recognition, spatial learning and memory function; but it did not impact novel object recognition. Importantly, treatment with DT restored cognitive function in LPS-infused animals and normalized the fraction of hippocampal neurons expressing the plasticity-related immediate-early gene Arc. Conclusion Our data demonstrate that the TNF-α synthesis inhibitor DT can significantly reverse hippocampus-dependent cognitive deficits induced by chronic neuroinflammation. These results suggest that TNF-α is a

  9. Natural Product Total Synthesis in the Organic Laboratory: Total Synthesis of Caffeic Acid Phenethyl Ester (CAPE), a Potent 5-Lipoxygenase Inhibitor from Honeybee Hives

    Science.gov (United States)

    Touaibia, Mohamed; Guay, Michel

    2011-01-01

    Natural products play a critical role in modern organic synthesis and learning synthetic techniques is an important component of the organic laboratory experience. In addition to traditional one-step organic synthesis laboratories, a multistep natural product synthesis is an interesting experiment to challenge students. The proposed three-step…

  10. Multipotent MAO and cholinesterase inhibitors for the treatment of Alzheimer's disease: synthesis, pharmacological analysis and molecular modeling of heterocyclic substituted alkyl and cycloalkyl propargyl amine.

    Science.gov (United States)

    Samadi, Abdelouahid; de los Ríos, Cristóbal; Bolea, Irene; Chioua, Mourad; Iriepa, Isabel; Moraleda, Ignacio; Bartolini, Manuela; Andrisano, Vincenza; Gálvez, Enrique; Valderas, Carolina; Unzeta, Mercedes; Marco-Contelles, José

    2012-06-01

    The synthesis, pharmacological evaluation and molecular modeling of heterocyclic substituted alkyl and cycloalkyl propargyl amines 1-7 of type I, and 9-12 of type II, designed as multipotent inhibitors able to simultaneously inhibit monoamine oxidases (MAO-A/B) as well as cholinesterase (AChE/BuChE) enzymes, as potential drugs for the treatment of Alzheimer's disease, are described. Indole derivatives 1-7 of type I are well known MAO inhibitors whose capacity to inhibit AChE and BuChE was here investigated for the first time. As a result, compound 7 was identified as a MAO-B inhibitor (IC(50) = 31 ± 2 nM) and a moderately selective eqBuChE inhibitor (IC(50) = 4.7 ± 0.2 μM). Conversely, the new and readily available 5-amino-7-(prop-2-yn-1-yl)-6,7,8,9-tetrahydropyrido[2,3-b][1,6]naphthyridine derivatives 9-13 of type II are poor MAO inhibitors, but showed AChE selective inhibition, compound 12 being the most attractive as it acts as a non-competitive inhibitor on EeAChE (IC(50) = 25 ± 3 nM, K(i) = 65 nM). The ability of this compound to interact with the AChE peripheral binding site was confirmed by kinetic studies and by molecular modeling investigation. Studies on human ChEs confirmed that 12 is a selective AChE inhibitor with inhibitory potency in the submicromolar range. Moreover, in agreement with its mode of action, 12 was shown to be able to inhibit Aβ aggregation induced by hAChE by 30.6%. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  11. Design, synthesis, and biological evaluation of enantiomeric beta-N-acetylhexosaminidase inhibitors LABNAc and DABNAc as potential agents against Tay-Sachs and Sandhoff disease.

    Science.gov (United States)

    Rountree, J S Shane; Butters, Terry D; Wormald, Mark R; Boomkamp, Stephanie D; Dwek, Raymond A; Asano, Naoki; Ikeda, Kyoko; Evinson, Emma L; Nash, Robert J; Fleet, George W J

    2009-03-01

    N-Acetylhexosaminidases are of considerable importance in mammals and are involved in various significant biological processes. In humans, deficiencies of these enzymes in the lysosome, resulting from inherited genetic defects, cause the glycolipid storage disorders Tay-Sachs and Sandhoff diseases. One promising therapy for these diseases involves the use of beta-N-acetylhexosaminidase inhibitors as chemical chaperones to enhance the enzyme activity above sub-critical levels. Herein we describe the synthesis and biological evaluation of a potent inhibitor, 2-acetamido-1,4-imino-1,2,4-trideoxy-L-arabinitol (LABNAc), in a high-yielding 11-step procedure from D-lyxonolactone. The N-benzyl and N-butyl analogues were also prepared and found to be potent inhibitors. The enantiomers DABNAc and NBn-DABNAc were synthesised from L-lyxonolactone, and were also evaluated. The L-iminosugar LABNAc and its derivatives were found to be potent noncompetitive inhibitors of some beta-N-acetylhexosaminidases, while the D-iminosugar DABNAc and its derivatives were found to be weaker competitive inhibitors. These results support previous work postulating that D-iminosugar mimics inhibit D-glycohydrolases competitively, and that their corresponding L-enantiomers show noncompetitive inhibition of these enzymes. Molecular modelling studies confirm that the spatial organisation in enantiomeric inhibitors leads to a different overlay with the monosaccharide substrate. Initial cell-based studies suggest that NBn-LABNAc can act as a chemical chaperone to enhance the deficient enzyme's activity to levels that may cause a positive pharmacological effect. LABNAc, NBn-LABNAc, and NBu-LABNAc are potent and selective inhibitors of beta-N-acetylhexosaminidase and may be useful as therapeutic agents for treating adult Tay-Sachs and Sandhoff diseases.

  12. The Impact of Selection with Diflubenzuron, a Chitin Synthesis Inhibitor, on the Fitness of Two Brazilian Aedes aegypti Field Populations

    Science.gov (United States)

    Belinato, Thiago Affonso; Valle, Denise

    2015-01-01

    Several Aedes aegypti field populations are resistant to neurotoxic insecticides, mainly organophoshates and pyrethroids, which are extensively used as larvicides and adulticides, respectively. Diflubenzuron (DFB), a chitin synthesis inhibitor (CSI), was recently approved for use in drinking water, and is presently employed in Brazil for Ae. aegypti control, against populations resistant to the organophosphate temephos. However, tests of DFB efficacy against field Ae. aegypti populations are lacking. In addition, information regarding the dynamics of CSI resistance, and characterization of any potential fitness effects that may arise in conjunction with resistance are essential for new Ae. aegypti control strategies. Here, the efficacy of DFB was evaluated for two Brazilian Ae. aegypti populations known to be resistant to both temephos and the pyrethroid deltamethrin. Laboratory selection for DFB resistance was then performed over six or seven generations, using a fixed dose of insecticide that inhibited 80% of adult emergence in the first generation. The selection process was stopped when adult emergence in the diflubenzuron-treated groups was equivalent to that of the control groups, kept without insecticide. Diflubenzuron was effective against the two Ae. aegypti field populations evaluated, regardless of their resistance level to neurotoxic insecticides. However, only a few generations of DFB selection were sufficient to change the susceptible status of both populations to this compound. Several aspects of mosquito biology were affected in both selected populations, indicating that diflubenzuron resistance acquisition is associated with a fitness cost. We believe that these results can significantly contribute to the design of control strategies involving the use of insect growth regulators. PMID:26107715

  13. A novel PKB/Akt inhibitor, MK-2206, effectively inhibits insulin-stimulated glucose metabolism and protein synthesis in isolated rat skeletal muscle.

    Science.gov (United States)

    Lai, Yu-Chiang; Liu, Yang; Jacobs, Roxane; Rider, Mark H

    2012-10-01

    PKB (protein kinase B), also known as Akt, is a key component of insulin signalling. Defects in PKB activation lead to insulin resistance and metabolic disorders, whereas PKB overactivation has been linked to tumour growth. Small-molecule PKB inhibitors have thus been developed for cancer treatment, but also represent useful tools to probe the roles of PKB in insulin action. In the present study, we examined the acute effects of two allosteric PKB inhibitors, MK-2206 and Akti 1/2 (Akti) on PKB signalling in incubated rat soleus muscles. We also assessed the effects of the compounds on insulin-stimulated glucose uptake, glycogen and protein synthesis. MK-2206 dose-dependently inhibited insulin-stimulated PKB phosphorylation, PKBβ activity and phosphorylation of PKB downstream targets (including glycogen synthase kinase-3α/β, proline-rich Akt substrate of 40 kDa and Akt substrate of 160 kDa). Insulin-stimulated glucose uptake, glycogen synthesis and glycogen synthase activity were also decreased by MK-2206 in a dose-dependent manner. Incubation with high doses of MK-2206 (10 μM) inhibited insulin-induced p70 ribosomal protein S6 kinase and 4E-BP1 (eukaryotic initiation factor 4E-binding protein-1) phosphorylation associated with increased eEF2 (eukaryotic elongation factor 2) phosphorylation. In contrast, Akti only modestly inhibited insulin-induced PKB and mTOR (mammalian target of rapamycin) signalling, with little or no effect on glucose uptake and protein synthesis. MK-2206, rather than Akti, would thus be the tool of choice for studying the role of PKB in insulin action in skeletal muscle. The results point to a key role for PKB in mediating insulin-stimulated glucose uptake, glycogen synthesis and protein synthesis in skeletal muscle.

  14. A Novel Pulse-Chase SILAC Strategy Measures Changes in Protein Decay and Synthesis Rates Induced by Perturbation of Proteostasis with an Hsp90 Inhibitor

    Science.gov (United States)

    Fierro-Monti, Ivo; Racle, Julien; Hernandez, Celine; Waridel, Patrice; Hatzimanikatis, Vassily; Quadroni, Manfredo

    2013-01-01

    Standard proteomics methods allow the relative quantitation of levels of thousands of proteins in two or more samples. While such methods are invaluable for defining the variations in protein concentrations which follow the perturbation of a biological system, they do not offer information on the mechanisms underlying such changes. Expanding on previous work [1], we developed a pulse-chase (pc) variant of SILAC (stable isotope labeling by amino acids in cell culture). pcSILAC can quantitate in one experiment and for two conditions the relative levels of proteins newly synthesized in a given time as well as the relative levels of remaining preexisting proteins. We validated the method studying the drug-mediated inhibition of the Hsp90 molecular chaperone, which is known to lead to increased synthesis of stress response proteins as well as the increased decay of Hsp90 “clients”. We showed that pcSILAC can give information on changes in global cellular proteostasis induced by treatment with the inhibitor, which are normally not captured by standard relative quantitation techniques. Furthermore, we have developed a mathematical model and computational framework that uses pcSILAC data to determine degradation constants kd and synthesis rates Vs for proteins in both control and drug-treated cells. The results show that Hsp90 inhibition induced a generalized slowdown of protein synthesis and an increase in protein decay. Treatment with the inhibitor also resulted in widespread protein-specific changes in relative synthesis rates, together with variations in protein decay rates. The latter were more restricted to individual proteins or protein families than the variations in synthesis. Our results establish pcSILAC as a viable workflow for the mechanistic dissection of changes in the proteome which follow perturbations. Data are available via ProteomeXchange with identifier PXD000538. PMID:24312217

  15. A novel pulse-chase SILAC strategy measures changes in protein decay and synthesis rates induced by perturbation of proteostasis with an Hsp90 inhibitor.

    Directory of Open Access Journals (Sweden)

    Ivo Fierro-Monti

    Full Text Available Standard proteomics methods allow the relative quantitation of levels of thousands of proteins in two or more samples. While such methods are invaluable for defining the variations in protein concentrations which follow the perturbation of a biological system, they do not offer information on the mechanisms underlying such changes. Expanding on previous work [1], we developed a pulse-chase (pc variant of SILAC (stable isotope labeling by amino acids in cell culture. pcSILAC can quantitate in one experiment and for two conditions the relative levels of proteins newly synthesized in a given time as well as the relative levels of remaining preexisting proteins. We validated the method studying the drug-mediated inhibition of the Hsp90 molecular chaperone, which is known to lead to increased synthesis of stress response proteins as well as the increased decay of Hsp90 "clients". We showed that pcSILAC can give information on changes in global cellular proteostasis induced by treatment with the inhibitor, which are normally not captured by standard relative quantitation techniques. Furthermore, we have developed a mathematical model and computational framework that uses pcSILAC data to determine degradation constants kd and synthesis rates Vs for proteins in both control and drug-treated cells. The results show that Hsp90 inhibition induced a generalized slowdown of protein synthesis and an increase in protein decay. Treatment with the inhibitor also resulted in widespread protein-specific changes in relative synthesis rates, together with variations in protein decay rates. The latter were more restricted to individual proteins or protein families than the variations in synthesis. Our results establish pcSILAC as a viable workflow for the mechanistic dissection of changes in the proteome which follow perturbations. Data are available via ProteomeXchange with identifier PXD000538.

  16. Inhibitors of Fatty Acid Synthesis Induce PPAR α -Regulated Fatty Acid β -Oxidative Genes: Synergistic Roles of L-FABP and Glucose.

    Science.gov (United States)

    Huang, Huan; McIntosh, Avery L; Martin, Gregory G; Petrescu, Anca D; Landrock, Kerstin K; Landrock, Danilo; Kier, Ann B; Schroeder, Friedhelm

    2013-01-01

    While TOFA (acetyl CoA carboxylase inhibitor) and C75 (fatty acid synthase inhibitor) prevent lipid accumulation by inhibiting fatty acid synthesis, the mechanism of action is not simply accounted for by inhibition of the enzymes alone. Liver fatty acid binding protein (L-FABP), a mediator of long chain fatty acid signaling to peroxisome proliferator-activated receptor- α (PPAR α ) in the nucleus, was found to bind TOFA and its activated CoA thioester, TOFyl-CoA, with high affinity while binding C75 and C75-CoA with lower affinity. Binding of TOFA and C75-CoA significantly altered L-FABP secondary structure. High (20 mM) but not physiological (6 mM) glucose conferred on both TOFA and C75 the ability to induce PPAR α transcription of the fatty acid β -oxidative enzymes CPT1A, CPT2, and ACOX1 in cultured primary hepatocytes from wild-type (WT) mice. However, L-FABP gene ablation abolished the effects of TOFA and C75 in the context of high glucose. These effects were not associated with an increased cellular level of unesterified fatty acids but rather by increased intracellular glucose. These findings suggested that L-FABP may function as an intracellular fatty acid synthesis inhibitor binding protein facilitating TOFA and C75-mediated induction of PPAR α in the context of high glucose at levels similar to those in uncontrolled diabetes.

  17. Suppression of Sirtuin-1 Increases IL-6 Expression by Activation of the Akt Pathway During Allergic Asthma

    Directory of Open Access Journals (Sweden)

    Lingling Tang

    2017-10-01

    Full Text Available Background/Aims: A growing number of studies have demonstrated that the activity and expression level of sirtuin-1 (SIRT1 are decreased in asthma patients; however, the mechanisms underlying decreased SIRT1 expression and function are still not completely understood. Interleukin (IL-6 plays important roles in inflammation during allergic asthma. In this study, we examined whether loss of SIRT1 activity regulated the expression of IL-6 and further verified the underlying mechanisms. Methods: The human airway epithelial cell line 16HBE was used to test the effects of the SIRT1 inhibitor (salermide on expression of IL-6. IL-6 mRNA and protein expression were assessed with real-time polymerase chain reaction (PCR, immunochemistry, and ELISA. OVA-challenged mice were used as an asthma model to investigate the effect of SIRT1 activation on IL-6 and relative Akt phosphorylation level. Results: We found that inhibition of SIRT1 increased IL-6 mRNA and protein levels in a time-dependent manner, which was accompanied by increased Akt pathway activation in 16HBE cells. Furthermore activation of Akt showed upregulated expression of the IL-6 protein whereas Akt inhibitor, LY294002 or Akt siRNA significantly inhibited SIRT1-regulated IL-6 expression. Conversely, activation of SIRT1 inhibited Akt activation and IL-6 expression in an asthmatic mice model and 16HBE cells. Conclusion: Our results indicate the potential role of SIRT1 in regulating inflammation by modulation of IL-6 expression in an Akt-dependent manner during allergic asthma.

  18. Sirtuin 1 (SIRT1 activation mediates sildenafil induced delayed cardioprotection against ischemia-reperfusion injury in mice.

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    Mona Shalwala

    Full Text Available BACKGROUND: It has been well documented that phosphodiesterase-5 inhibitor, sildenafil (SIL protects against myocardial ischemia/reperfusion (I-R injury. SIRT1 is part of the class III Sirtuin family of histone deacetylases that deacetylates proteins involved in cellular stress response including those related to I-R injury. OBJECTIVE/HYPOTHESIS: We tested the hypothesis that SIL-induced cardioprotection may be mediated through activation of SIRT1. METHODS: Adult male ICR mice were treated with SIL (0.7 mg/kg, i.p., Resveratrol (RSV, 5 mg/kg, a putative activator of SIRT1 used as the positive control, or saline (0.2 mL. The hearts were harvested 24 hours later and homogenized for SIRT1 activity analysis. RESULTS: Both SIL- and RSV-treated mice had increased cardiac SIRT1 activity (P<0.001 as compared to the saline-treated controls 24 hours after drug treatment. In isolated ventricular cardiomyocytes, pretreatment with SIL (1 µM or RSV (1 µM for one hour in vitro also upregulated SIRT1 activity (P<0.05. We further examined the causative relationship between SIRT1 activation and SIL-induced late cardioprotection. Pretreatment with SIL (or RSV 24 hours prior to 30 min ischemia and 24 hours of reperfusion significantly reduced infarct size, which was associated with a significant increase in SIRT1 activity (P<0.05. Moreover, sirtinol (a SIRT1 inhibitor, 5 mg/kg, i.p. given 30 min before I-R blunted the infarct-limiting effect of SIL and RSV (P<0.001. CONCLUSION: Our study shows that activation of SIRT1 following SIL treatment plays an essential role in mediating the SIL-induced cardioprotection against I-R injury. This newly identified SIRT1-activating property of SIL may have enormous therapeutic implications.

  19. Synthesis, biological assessment and molecular modeling of new dihydroquinoline-3-carboxamides and dihydroquinoline-3-carbohydrazide derivatives as cholinesterase inhibitors, and Ca channel antagonists.

    Science.gov (United States)

    Tomassoli, Isabelle; Ismaili, Lhassane; Pudlo, Marc; de Los Ríos, Cristóbal; Soriano, Elena; Colmena, Inés; Gandía, Luis; Rivas, Luis; Samadi, Abdelouahid; Marco-Contelles, José; Refouvelet, Bernard

    2011-01-01

    The synthesis, biological evaluation, and molecular modeling of new 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxamides(4), 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carbohydrazide (6), and some hexahydropyrimido[5,4-c]quinoline-2,5-diones (9) produced earlier by our laboratory, as AChE/BuChE inhibitors, is described. From these analyses compound 4c resulted equipotent regarding the inhibition of cholinesterases'; inhibitors 6k, 9a, 9b were selective for AChE, whereas product 4d proved selective for BuChE. Docking analysis has been carry out in order to identify the binding mode in the active site, and to explain the observed selectivities. Only compound 9a has been shown to decrease K(+)-induced calcium signals in bovine chromaffin cells. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  20. Epitope targeting of tertiary protein structure enables target-guided synthesis of a potent in-cell inhibitor of botulinum neurotoxin.

    Science.gov (United States)

    Farrow, Blake; Wong, Michelle; Malette, Jacquie; Lai, Bert; Deyle, Kaycie M; Das, Samir; Nag, Arundhati; Agnew, Heather D; Heath, James R

    2015-06-08

    Botulinum neurotoxin (BoNT) serotype A is the most lethal known toxin and has an occluded structure, which prevents direct inhibition of its active site before it enters the cytosol. Target-guided synthesis by in situ click chemistry is combined with synthetic epitope targeting to exploit the tertiary structure of the BoNT protein as a landscape for assembling a competitive inhibitor. A substrate-mimicking peptide macrocycle is used as a direct inhibitor of BoNT. An epitope-targeting in situ click screen is utilized to identify a second peptide macrocycle ligand that binds to an epitope that, in the folded BoNT structure, is active-site-adjacent. A second in situ click screen identifies a molecular bridge between the two macrocycles. The resulting divalent inhibitor exhibits an in vitro inhibition constant of 165 pM against the BoNT/A catalytic chain. The inhibitor is carried into cells by the intact holotoxin, and demonstrates protection and rescue of BoNT intoxication in a human neuron model. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A multidisciplinary study of 3-(β-d-glucopyranosyl)-5-substituted-1,2,4-triazole derivatives as glycogen phosphorylase inhibitors: Computation, synthesis, crystallography and kinetics reveal new potent inhibitors.

    Science.gov (United States)

    Kun, Sándor; Begum, Jaida; Kyriakis, Efthimios; Stamati, Evgenia C V; Barkas, Thomas A; Szennyes, Eszter; Bokor, Éva; Szabó, Katalin E; Stravodimos, George A; Sipos, Ádám; Docsa, Tibor; Gergely, Pál; Moffatt, Colin; Patraskaki, Myrto S; Kokolaki, Maria C; Gkerdi, Alkistis; Skamnaki, Vassiliki T; Leonidas, Demetres D; Somsák, László; Hayes, Joseph M

    2018-03-10

    3-(β-d-Glucopyranosyl)-5-substituted-1,2,4-triazoles have been revealed as an effective scaffold for the development of potent glycogen phosphorylase (GP) inhibitors but with the potency very sensitive to the nature of the alkyl/aryl 5-substituent (Kun et al., Eur. J. Med. Chem. 2014, 76, 567). For a training set of these ligands, quantum mechanics-polarized ligand docking (QM-PLD) demonstrated good potential to identify larger differences in potencies (predictive index PI = 0.82) and potent inhibitors with K i 's synthesis. The compounds were prepared in O-perbenzoylated forms by either ring transformation of 5-β-d-glucopyranosyl tetrazole by N-benzyl-arenecarboximidoyl chlorides, ring closure of C-(β-d-glucopyranosyl)formamidrazone with aroyl chlorides, or that of N-(β-d-glucopyranosylcarbonyl)arenethiocarboxamides by hydrazine, followed by deprotections. Kinetics experiments against rabbit muscle GPb (rmGPb) and human liver GPa (hlGPa) revealed five compounds as potent low μM inhibitors with three of these on the submicromolar range for rmGPa. X-ray crystallographic analysis sourced the potency to a combination of favorable interactions from the 1,2,4-triazole and suitable aryl substituents in the GP catalytic site. The compounds also revealed promising calculated pharmacokinetic profiles. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  2. Finding Potent Sirt Inhibitor in Coffee: Isolation, Confirmation and Synthesis of Javamide-II (N-Caffeoyltryptophan as Sirt1/2 Inhibitor.

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    Jae B Park

    Full Text Available Recent studies suggest that Sirt inhibition may have beneficial effects on several human diseases such as neurodegenerative diseases and cancer. Coffee is one of most popular beverages with several positive health effects. Therefore, in this paper, potential Sirt inhibitors were screened using coffee extract. First, HPLC was utilized to fractionate coffee extract, then screened using a Sirt1/2 inhibition assay. The screening led to the isolation of a potent Sirt1/2 inhibitor, whose structure was determined as javamide-II (N-caffeoyltryptophan by NMR. For confirmation, the amide was chemically synthesized and its capacity of inhibiting Sirt1/2 was also compared with the isolated amide. Javamide-II inhibited Sirt2 (IC50; 8.7 μM better than Sirt1(IC50; 34μM. Since javamide-II is a stronger inhibitor for Sirt2 than Sirt1. The kinetic study was performed against Sirt2. The amide exhibited noncompetitive Sirt2 inhibition against the NAD+ (Ki = 9.8 μM and showed competitive inhibition against the peptide substrate (Ki = 5.3 μM. Also, a docking simulation showed stronger binding pose of javamide-II to Sirt2 than AGK2. In cellular levels, javamide-II was able to increase the acetylation of total lysine, cortactin and histone H3 in neuronal NG108-15 cells. In the same cells, the amide also increased the acetylation of lysine (K382 in p53, but not (K305. This study suggests that Javamide-II found in coffee may be a potent Sirt1/2 inhibitor, probably with potential use in some conditions of human diseases.

  3. Design and synthesis of novel N-benzylidenesulfonohydrazide inhibitors of MurC and MurD as potential antibacterial agents.

    Science.gov (United States)

    Frlan, Rok; Kovac, Andreja; Blanot, Didier; Gobec, Stanislav; Pecar, Slavko; Obreza, Ales

    2008-01-11

    A series of novel N-benzylidenesulfonohydrazide compounds were designed and synthesized as inhibitors of UDP-N-acetylmuramic acid: L-alanine ligase (MurC) and UDP-N-acetylmuramoyl-L-alanine: D-glutamate ligase (MurD) from E. coli, involved in the biosynthesis of bacterial cell-walls. Some compounds possessed inhibitory activity against both enzymes with IC(50) values as low as 30 microM. In addition, a new, one-pot synthesis of amidobenzaldehydes is reported.

  4. Thiocarbamate-Directed Tandem Olefination-Intramolecular Sulfuration of Two Ortho C-H Bonds: Application to Synthesis of a COX-2 Inhibitor.

    Science.gov (United States)

    Li, Wendong; Zhao, Yingwei; Mai, Shaoyu; Song, Qiuling

    2018-02-16

    A palladium-catalyzed dual ortho C-H bond activation of aryl thiocarbamates is developed. This tandem reaction initiates by thiocarbamate-directed ortho C-H palladation, which leads to favorable olefin insertion rather than reductive elimination. The oxidative Heck reaction followed by another C-H activation and sulfuration affords the dual-functionalized products. This reaction provides a concise route to the S,O,C multisubstituted benzene skeleton which could be successfully applied for the synthesis of a COX-2 inhibitor.

  5. Development of a UV-Cleavable Protecting Group for Hydroxylamines, Synthesis of a StructurallyWide Variety of Hydroxamic Acids, and Identification of Histone Deacetylase Inhibitors

    DEFF Research Database (Denmark)

    Mortensen, Kim Thollund

    Photo-cleavable protecting groups are highly applicable for the synthesis of structural complex and sensitive compounds, including biological important molecules. Herein, we present the development of a novel O-hydroxylamine photo-cleavable protecting group, based on the methyl-6-nitroveratryl...... moiety. We demonstrate the application of the protected hydroxylamine derivative for the synthesis of N-alkylated hydroxamic acids. We have shown that the construct is stable toward a diverse set of reaction conditions, as well as orthogonal with conventional protection groups. The O......-protected hydroxylamine derivative was applied to synthesize a small collection of N-alkylated hydroxamic acids as inhibitors of the histone deacetylase enzymes, an important class of enzymes for the treatment of a range of diseases, most importantly cancer. During my external stay at Nanyang Technological University...

  6. Synthesis and PET studies of [11C-cyano]letrozole (Femara®), an aromatase inhibitor drug

    Science.gov (United States)

    Kil, Kun-Eek; Biegon, Anat; Ding, Yu-Shin; Fischer, Andre; Ferrieri, Richard A.; Kim, Sung Won; Pareto, Deborah; Schueller, Michael J.; Fowler, Joanna S.

    2011-01-01

    Introduction Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone to estrone and estradiol respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole, Femara®) is a high affinity aromatase inhibitor (Ki=11.5 nM) which has FDA approval for breast cancer treatment. Here we report the synthesis of carbon-11 labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile, 3) were prepared in two-step syntheses from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [11C]cyano group was introduced via the tetrakis(triphenylphosphine)palladium(0) catalyzed coupling of [11C]cyanide with the bromo-precursor (3). PET studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. The free fraction of letrozole in the plasma, log D, and the [11C-cyano]letrozole fraction in the arterial plasma were also measured. Results [11C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79–80%, with a radiochemical purity greater than 98% and a specific activity of 4.16±2.21 Ci/μmol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance followed by slow clearance of carbon-11 from the brain with no difference between brain regions. The brain kinetics was not affected by co-injection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9% and log D was 1.84. Conclusion [11C-cyano]Letrozole is readily synthesized via a palladium catalyzed coupling reaction with [11C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase as revealed by the absence of regional specificity and saturability in brain regions, such as amygdala, which are known to contain

  7. In Silico Screening, Synthesis and In Vitro Evaluation of Some Quinazolinone and Pyridine Derivatives as Dihydrofolate Reductase Inhibitors for Anticancer Activity

    Directory of Open Access Journals (Sweden)

    A. G. Nerkar

    2009-01-01

    Full Text Available Dihydrofolate reductase (DHFR is the important target for anticancer drugs belonging to the class of antimetabolites as the enzyme plays important role in the de novo purine synthesis. We here report the in silico screening to obtain best fit molecules as DHFR inhibitors, synthesis of some ʻbest fitʼ quinazolinone from 2-phenyl-3-(substituted-benzilidine-amino quinazolinones (Quinazolinone Shiff's bases QSB1-5 and pyridine-4-carbohydrazide Shiff's bases (ISB1-5 derivatives and their in vitro anticancer assay. Synthesis of the molecules was performed using microwave assisted synthesis. The structures of these molecules were elucidated by IR and 1H-NMR. These compounds were then subjected for in vitro anticancer evaluation against five human cancer cell-lines for anticancer cyto-toxicity assay. Methotrexate (MTX was used as standard for this evaluation to give a comparable inhibition of the cell proliferation by DHFR inhibition. Placlitaxel, adriamycin and 5-fluoro-uracil were also used as standard to give a comparable activity of these compounds with other mechanism of anticancer activity. ISB3 (4-(N, N-dimethyl-amino-phenyl Schiff''s base derivative of pyridine carbohydrazide showed equipotent activity with the standards used in in vitro anticancer assay as per the NCI (National Cancer Institute guidelines.

  8. Rational design and synthesis of new quorum-sensing inhibitors derived from acylated homoserine lactones and natural products from garlic

    DEFF Research Database (Denmark)

    Persson, T.; Rasmussen, Thomas Bovbjerg; Skindersoe, M.

    2005-01-01

    within the binding-site and structural motifs in molecular components isolated from garlic, 7 and 8, shown to be quorum-sensing inhibitors but not antibiotics. A potent quorum-sensing inhibitor N-(heptylsulfanylacetyl)-L-homoserine lactone (10c) was identified. Together with data collected for the other...

  9. Sirtuin 7 is decreased in pulmonary fibrosis and regulates the fibrotic phenotype of lung fibroblasts.

    Science.gov (United States)

    Wyman, Anne E; Noor, Zahid; Fishelevich, Rita; Lockatell, Virginia; Shah, Nirav G; Todd, Nevins W; Atamas, Sergei P

    2017-06-01

    Pulmonary fibrosis is a severe condition with no cure and limited therapeutic options. A better understanding of its pathophysiology is needed. Recent studies have suggested that pulmonary fibrosis may be driven by accelerated aging-related mechanisms. Sirtuins (SIRTs), particularly SIRT1, SIRT3, and SIRT6, are well-known mediators of aging; however, limited data exist on the contribution of sirtuins to lung fibrosis. We assessed the mRNA and protein levels of all seven known sirtuins in primary lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated interstitial lung disease (SSc-ILD) in comparison with lung fibroblasts from healthy controls. These unbiased tests revealed a tendency for all sirtuins to be expressed at lower levels in fibroblasts from patients compared with controls, but the greatest decrease was observed with SIRT7. Similarly, SIRT7 was decreased in lung tissues of bleomycin-challenged mice. Inhibition of SIRT7 with siRNA in cultured lung fibroblasts resulted in an increase in collagen and α-smooth muscle actin (α-SMA). Reciprocally, overexpression of SIRT7 resulted in lower basal and TGF-β-induced levels of COL1A1, COL1A2, COL3A1, and α-SMA mRNAs, as well as collagen and α-SMA proteins. Induced changes in SIRT7 had no effect on endogenous TGF-β mRNA levels or latent TGF-β activation, but overexpression of SIRT7 reduced the levels of Smad3 mRNA and protein. In conclusion, the decline in SIRT7 in lung fibroblasts has a profibrotic effect, which is mediated by changes in Smad3 levels.

  10. Trichloroacetimidates as Alkylating Reagents and Their Application in the Synthesis of Pyrroloindoline Natural Products and Synthesis of Small Molecule Inhibitors of Src Homology 2 Domain-Containing Inositol Phosphatase (SHIP)

    Science.gov (United States)

    Adhikari, Arijit A.

    was applied towards the synthesis of natural products and their analogs. The pyrroloindoline ring system is found in many alkaloids and cyclic peptides which mainly differ in the substitution at the C3a position. To provide rapid access to these natural products a diversity-oriented strategy was established via displacement of C3a-trichloroacetimidate pyrroloindoline. Carbon, oxygen, sulfur and nitrogen nucleophiles were all shown to undergo substitution reactions with these trichloroacetimidates in the presence of a Lewis acid catalyst. In order to demonstrate the utility of this new method it was applied towards the synthesis of arundinine and a formal synthesis of psychotriasine. Current investigations involve the application of this method towards the synthesis of a complex pyrroloindoline natural product kapakahine C and the progress made therein has been discussed. The reactivity of trichloroacetimidates was also investigated for the selective C3-alkylation of 2,3-disubstituted indoles to provide indolenines. Indolenines serve as useful intermediates in the synthesis of many complex alkaloids. Different benzylic and allylic trichloroacetimidates were shown to provide 3,3'-disubstituted indolenines with high yields in the presence of catalytic amounts of Lewis acids. Various substituted indoles were evaluated under these reaction conditions. This methodology was also applied towards the synthesis of the core tetracyclic ring system found in communesin natural products. In addition to the above work, synthesis of small molecule inhibitors of Src Homology 2 Domain-Containing Inositol Phosphatase (SHIP) has also been described. Aberrations in the phosphoinositide 3-kinase (PI3K) cellular signaling pathway can lead to diseased cellular states like cancer. Herein we have reported stereoselective synthesis of two quinoline based small molecule SHIP inhibitors. The lead compounds and their analogs were tested for their activities against SHIP by Malachite green assay

  11. Design, synthesis, and evaluation of bioactive molecules; Quantification of tricyclic pyrones from pharmacokinetic studies; Nanodelivery of siRNA; and Synthesis of viral protease inhibitors

    Science.gov (United States)

    Weerasekara, Sahani Manjitha

    Four research projects were carried out and they are described in this dissertation. Glycogen synthase kinase-3 beta (GSK3?) plays a pivotal and central role in the pathogenesis of Alzheimer's disease (AD) and protein kinase C (PKC) controls the function of other proteins via phosphorylation and involves in tumor promotion. In pursuit of identifying novel GSK3beta and/or PKC inhibitors, substituted quinoline molecules were designed and synthesized based on the structure-activity-relationship studies. Synthesized molecules were evaluated for their neural protective activities and selected molecules were further tested for inhibitory activities on GSK3beta and PKC enzymes. Among these compounds, compound 2 was found to have better GSK3beta enzyme inhibitory and MC65 cell protection activities at low nanomolar concentrations and poor PKC inhibitory activity whereas compound 3 shows better PKC inhibitory activity. This demonstrates the potential for uses of quinoline scaffold in designing novel compounds for AD and cancer. Pharmacokinetics and distribution profiles of two anti-Alzheimer molecules, CP2 and TP70, discovered in our laboratory were assessed using HPLC/MS. Plasma samples of mice and rats fed with TP70 via different routes over various times were analyzed to quantify the amounts of TP70 in plasma of both species. Distribution profiles of TP70 in various tissues of mice were studied and results show that TP70 penetrated the blood brain barrier and accumulated in the brain tissue in significant amounts. Similarly, the amount of CP2 in plasma of mice was analyzed. The HPLC analysis revealed that both compounds have good PK profiles and bioavailability, which would make them suitable candidates for further in vivo efficacy studies. Nanodelivery of specific dsRNA for suppressing the western corn rootworm (WCR, Diabrotica virgifera virgifera) genes was studied using modified chitosan or modified polyvinylpyrrolidinone (PVP) as nanocarriers. Computational

  12. Synthesis and Biological Evaluation of Novel Jatrorrhizine Derivatives with Amino Groups Linked at the 3-Position as Inhibitors of Acetylcholinesterase

    Directory of Open Access Journals (Sweden)

    Xiaofei Jiang

    2017-01-01

    Full Text Available Jatrorrhizine was considered as one of the active constituents of Coptis chinensis Franch. Herein, jatrorrhizine derivatives with substituted amino groups linked at the 3-position were designed, synthesized, and biologically evaluated as inhibitors of acetylcholinesterase. Jatrorrhizine derivatives inhibited the activity of acetylcholinesterase (AChE to a greater extent than the lead compound jatrorrhizine. All these jatrorrhizine derivatives were proved to be potent inhibitors of acetylcholinesterase (AChE with submicromolar IC50 values, but less sensitive to butyrylcholinesterase (BuChE, which suggests that these jatrorrhizine derivatives are selective for AChE/BuChE. Compound 3g gave the most potent inhibitor activity for AChE (IC50 = 0.301 μM, which is greater than the lead compound jatrorrhizine. All these results demonstrated that these jatrorrhizine derivatives are potential inhibitors for AChE.

  13. Synthesis and structure-activity relationship of α-keto amides as enterovirus 71 3C protease inhibitors.

    Science.gov (United States)

    Zeng, Debin; Ma, Yuying; Zhang, Rui; Nie, Quandeng; Cui, Zhengjie; Wang, Yaxin; Shang, Luqing; Yin, Zheng

    2016-04-01

    α-Keto amide derivatives as enterovirus 71 (EV71) 3C protease (3C(pro)) inhibitors have been synthesized and assayed for their biochemical and antiviral activities. structure-activity relationship (SAR) study indicated that small moieties were primarily tolerated at P1' and the introduction of para-fluoro benzyl at P2 notably improved the potency of inhibitor. Inhibitors 8v, 8w and 8x exhibited satisfactory activity (IC50=1.32±0.26μM, 1.88±0.35μM and 1.52±0.31μM, respectively) and favorable CC50 values (CC50>100μM). α-Keto amide may represent a good choice as a warhead for EV71 3C(pro) inhibitor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A focused fragment library targeting the antibiotic resistance enzyme - Oxacillinase-48: Synthesis, structural evaluation and inhibitor design.

    Science.gov (United States)

    Akhter, Sundus; Lund, Bjarte Aarmo; Ismael, Aya; Langer, Manuel; Isaksson, Johan; Christopeit, Tony; Leiros, Hanna-Kirsti S; Bayer, Annette

    2018-02-10

    β-Lactam antibiotics are of utmost importance when treating bacterial infections in the medical community. However, currently their utility is threatened by the emergence and spread of β-lactam resistance. The most prevalent resistance mechanism to β-lactam antibiotics is expression of β-lactamase enzymes. One way to overcome resistance caused by β-lactamases, is the development of β-lactamase inhibitors and today several β-lactamase inhibitors e.g. avibactam, are approved in the clinic. Our focus is the oxacillinase-48 (OXA-48), an enzyme reported to spread rapidly across the world and commonly identified in Escherichia coli and Klebsiella pneumoniae. To guide inhibitor design, we used diversely substituted 3-aryl and 3-heteroaryl benzoic acids to probe the active site of OXA-48 for useful enzyme-inhibitor interactions. In the presented study, a focused fragment library containing 49 3-substituted benzoic acid derivatives were synthesised and biochemically characterized. Based on crystallographic data from 33 fragment-enzyme complexes, the fragments could be classified into R 1 or R 2 binders by their overall binding conformation in relation to the binding of the R 1 and R 2 side groups of imipenem. Moreover, binding interactions attractive for future inhibitor design were found and their usefulness explored by the rational design and evaluation of merged inhibitors from orthogonally binding fragments. The best inhibitors among the resulting 3,5-disubstituted benzoic acids showed inhibitory potential in the low micromolar range (IC 50  = 2.9 μM). For these inhibitors, the complex X-ray structures revealed non-covalent binding to Arg250, Arg214 and Tyr211 in the active site and the interactions observed with the mono-substituted fragments were also identified in the merged structures. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  15. Design and synthesis of N₁-aryl-benzimidazoles 2-substituted as novel HIV-1 non-nucleoside reverse transcriptase inhibitors.

    Science.gov (United States)

    Monforte, Anna-Maria; Ferro, Stefania; De Luca, Laura; Lo Surdo, Giuseppa; Morreale, Francesca; Pannecouque, Christophe; Balzarini, Jan; Chimirri, Alba

    2014-02-15

    A series of novel N1-aryl-2-arylthioacetamido-benzimidazoles were synthesized and evaluated as inhibitors of human immunodeficiency virus type-1 (HIV-1). Some of them proved to be effective in inhibiting HIV-1 replication at submicromolar and nanomolar concentration acting as HIV-1 non-nucleoside RT inhibitors (NNRTIs), with low cytotoxicity. The preliminary structure-activity relationship (SAR) of these new derivatives was discussed and rationalized by docking studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Lack of effect of inhibitors of DNA synthesis/repair on the ionizing radiation-induced chromosomal damage in G[sub 2] stage of ataxia telangiectasia cells

    Energy Technology Data Exchange (ETDEWEB)

    Antoccia, A. (Univ. ' La Sapienza' , Rome (Italy). Dipt. di Genetica e Biologia Molecolare); Palitti, F.; Raggi, T. (Univ. del Tuscia, Viterbo (Italy). Dipt. di Agrobiologia ed Agrochimica); Catena, C. (ENEA, Casaccia (Italy). Centro Ricerche Energia); Tanzarella, C. (Rome Univ. 3 (Italy). Dipt. di Biologia)

    1994-09-01

    The relationship between the repair processes occurring at the G[sub 2] phase of the cell cycle and cytogenetic damage in ataxia telangiectasia (AT) cells was studied. Lymphoblastoid cells derived from normal, heterozygote AT (HzAT) and three AT patients were exposed to X-rays or fission neutrons and post-treated with inhibitors of DNA synthesis/repair, such as inhibitors of DNA polymerases [alpha], [sigma] and [epsilon] (cytosine arabinoside, ara-C; aphidicolin, APC; buthylphenyl-guanine, BuPdG) or ribonucleotide reductase (hydroxyurea HU). A strong increase of radiation-induced chromosomal aberrations was observed in normal and HzAT cells post-treated with ara-C, APC and HU, but not in the presence of BuPdG. No enhancing effect was observed in cells derived from AT patients, except for HU post-irradiation treatment. These results suggest that the enzymes that can be inhibited by these agents are not directly involved in the repair of radiation damage induced in G[sub 2] cells from AT patients, indicating that probably the AT cells that we used lack the capability to transform the primary DNA lesions into reparable products, or that AT cells might contain a mutated form of DNA polymerase resistant to the inhibitors. (author).

  17. Severe Acute Respiratory Syndrome-Coronavirus Papain-Like Novel Protease Inhibitors: Design, Synthesis, Protein-Ligand X-ray Structure and Biological Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Takayama, Jun; Rao, Kalapala Venkateswar; Ratia, Kiira; Chaudhuri, Rima; Mulhearn, Debbie C.; Lee, Hyun; Nichols, Daniel B.; Baliji, Surendranath; Baker, Susan C.; Johnson, Michael E.; Mesecar, Andrew D. (Purdue); (UC); (UIC)

    2012-02-21

    The design, synthesis, X-ray crystal structure, molecular modeling, and biological evaluation of a series of new generation SARS-CoV PLpro inhibitors are described. A new lead compound 3 (6577871) was identified via high-throughput screening of a diverse chemical library. Subsequently, we carried out lead optimization and structure-activity studies to provide a series of improved inhibitors that show potent PLpro inhibition and antiviral activity against SARS-CoV infected Vero E6 cells. Interestingly, the (S)-Me inhibitor 15h (enzyme IC{sub 50} = 0.56 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) and the corresponding (R)-Me 15g (IC{sub 50} = 0.32 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) are the most potent compounds in this series, with nearly equivalent enzymatic inhibition and antiviral activity. A protein-ligand X-ray structure of 15g-bound SARS-CoV PLpro and a corresponding model of 15h docked to PLpro provide intriguing molecular insight into the ligand-binding site interactions.

  18. Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death.

    Science.gov (United States)

    Guida, Natascia; Laudati, Giusy; Anzilotti, Serenella; Secondo, Agnese; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M T; Formisano, Luigi

    2015-11-01

    Resveratrol (3,5,4'-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Synthesis of deleobuvir, a potent hepatitis C virus polymerase inhibitor, and its major metabolites labeled with carbon-13 and carbon-14.

    Science.gov (United States)

    Latli, Bachir; Hrapchak, Matt; Chevliakov, Maxim; Li, Guisheng; Campbell, Scot; Busacca, Carl A; Senanayake, Chris H

    2015-05-30

    Deleobuvir, (2E)-3-(2-{1-[2-(5-bromopyrimidin-2-yl)-3-cyclopentyl-1-methyl-1H-indole-6-carboxamido]cyclobutyl}-1-methyl-1H-benzimidazol-6-yl)prop-2-enoic acid (1), is a non-nucleoside, potent, and selective inhibitor of hepatitis C virus NS5B polymerase. Herein, we describe the detailed synthesis of this compound labeled with carbon-13 and carbon-14. The synthesis of its three major metabolites, namely, the reduced double bond metabolite (2) and the acyl glucuronide derivatives of (1) and (2), is also reported. Aniline-(13) C6 was the starting material to prepare butyl (E)-3-(3-methylamino-4-nitrophenyl-(13) C6 )acrylate [(13) C6 ]-(11) in six steps. This intermediate was then used to obtain [(13) C6 ]-(1) and [(13) C6 ]-(2) in five and four more steps, respectively. For the radioactive synthesis, potassium cyanide-(14) C was used to prepare 1-cylobutylaminoacid [(14) C]-(23) via Buchrer-Bergs reaction. The carbonyl chloride of this acid was then used to access both [(14) C]-(1) and [(14) C]-(2) in four steps. The acyl glucuronide derivatives [(13) C6 ]-(3), [(13) C6 ]-(4) and [(14) C]-(3) were synthesized in three steps from the acids [(13) C6 ]-(1), [(13) C6 ]-(2) and [(14) C]-(1) using known procedures. Copyright © 2015 John Wiley & Sons, Ltd.

  20. The Effect of Aerobic Training on Metabolic Parameters and Serum Level of Sirtuin1 in Women with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Abbas Saremi

    2016-12-01

    Full Text Available Abstract Background: Sirtuin-1 regulates important cellular processes, including apoptosis, cellular senescence, and metabolism. Therefore, sirtuin-1 may be a novel therapeutic target for type 2 diabetes. The aim of this study was to investigate the effect of 8 weeks aerobic training on sirtuin-1 level and cardiometabolic parameters in women with type 2 diabetes. Materials and Methods: In this semi-experimental study with pretest – posttest design, twenty diabetic women (aged 43.92±5.2 y were randomly assigned to aerobic training or non-exercising control groups. Aerobic training program was performed 50-60 min/d, 3d/wk, for 2 months. Serum levels of sirtuin-1, body composition and metabolic parameters were assessed before and after the training period. Data were analyzed by paired T test. Results: Adiposity indices, total cholesterol, triglyceride, LDL- cholesterol,blood glucose and insulin resistance index were significantly reduced in the intervention group compared to the control (p<0.05. Also, sirtuin-1 level was increased in the intervention group compared to the control (p<0.05. Conclusion: These findings show that aerobic exercise is associated with an improvement in siruin-1 levels and metabolic indices in women with type 2 diabetes.

  1. Curcumin elevates sirtuin level but does not postpone in vitro senescence of human cells building the vasculature

    Science.gov (United States)

    Grabowska, Wioleta; Suszek, Małgorzata; Wnuk, Maciej; Lewinska, Anna; Wasiak, Emilia; Sikora, Ewa; Bielak-Zmijewska, Anna

    2016-01-01

    It is believed that curcumin, a component of the turmeric that belongs to hormetins, possesses anti-aging propensity. This property of curcumin can be partially explained by its influence on the level of sirtuins. Previously, we have shown that relatively high (2.5-10 μM) doses of curcumin induce senescence of cancer cells and cells building the vasculature. In the present study we examined whether curcumin at low doses (0.1 and 1 μM) is able to delay cell senescence and upregulate the level of sirtuins in human cells building the vasculature, namely vascular smooth muscle (VSMC) and endothelial (EC) cells. To this end we used cells senescing in a replicative and premature manner. We showed that low doses of curcumin in case of VSMC neither postponed the replicative senescence nor protected from premature senescence induced by doxorubicin. Moreover, curcumin slightly accelerated replicative senescence of EC. Despite some fluctuations, a clear increasing tendency in the level of sirtuins was observed in curcumin-treated young, senescing or already senescent cells. Sirtuin activation could be caused by the activation of AMPK resulting from superoxide elevation and ATP reduction. Our results show that curcumin at low doses can increase the level of sirtuins without delaying senescence of VSMC. PMID:27034011

  2. Identification of an inhibitor of the MurC enzyme, which catalyzes an essential step in the peptidoglycan precursor synthesis pathway.

    Science.gov (United States)

    Zawadzke, Laura E; Norcia, Michael; Desbonnet, Charlene R; Wang, Hong; Freeman-Cook, Kevin; Dougherty, Thomas J

    2008-02-01

    The pathway for synthesis of the peptidoglycan precursor UDP-N-acetylmuramyl pentapeptide is essential in Gram-positive and Gram-negative bacteria. This pathway has been exploited in the recent past to identify potential new antibiotics as inhibitors of one or more of the Mur enzymes. In the present study, a high-throughput screen was employed to identify potential inhibitors of the Escherichia coli MurC (UDP-N-acetylmuramic acid:L-alanine ligase), the first of four paralogous amino acid-adding enzymes. Inhibition of ATP consumed during the MurC reaction, using an adaptation of a kinase assay format, identified a number of potential inhibitory chemotypes. After nonspecific inhibition testing and chemical attractiveness were assessed, C-1 emerged as a compound for further characterization. The inhibition of MurC by this compound was confirmed in both a kinetic-coupled enzyme assay and a direct nuclear magnetic resonance product detection assay. C-1 was found to be a low micromolar inhibitor of the E. coli MurC reaction, with preferential inhibition by one of two enantiomeric forms. Experiments indicated that it was a competitive inhibitor of ATP binding to the MurC enzyme. Further work with MurC enzymes from several bacterial sources revealed that while the compound was equally effective at inhibiting MurC from genera (Proteus mirabilis and Klebsiella pneumoniae) closely related to E. coli, MurC enzymes from more distant Gram-negative species such as Haemophilus influenzae, Acinetobacter baylyi, and Pseudomonas aeruginosa were not inhibited.

  3. Synthesis and discovery of highly functionalized mono- and bis-spiro-pyrrolidines as potent cholinesterase enzyme inhibitors.

    Science.gov (United States)

    Kia, Yalda; Osman, Hasnah; Suresh Kumar, Raju; Basiri, Alireza; Murugaiyah, Vikneswaran

    2014-04-01

    Novel mono and bis spiropyrrolidine derivatives were synthesized via an efficient ionic liquid mediated, 1,3-dipolar cycloaddition methodology and evaluated in vitro for their AChE and BChE inhibitory activities in search for potent cholinesterase enzyme inhibitors. Most of the synthesized compounds displayed remarkable AChE inhibitory activities with IC50 values ranging from 1.68 to 21.85 μM, wherein compounds 8d and 8j were found to be most active inhibitors against AChE and BChE with IC50 values of 1.68 and 2.75 μM, respectively. Molecular modeling simulation on Torpedo californica AChE and human BChE receptors, showed good correlation between IC50 values and binding interaction template of the most active inhibitors docked into the active site of their relevant enzymes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Synthesis and Activity of a New Series of(Z-3-Phenyl-2-benzoylpropenoic Acid Derivatives as Aldose Reductase Inhibitors

    Directory of Open Access Journals (Sweden)

    Shao-Jie Wang

    2007-04-01

    Full Text Available During the course of studies directed towards the discovery of novel aldose reductase inhibitors for the treatment of diabetic complications, we synthesized a series of new (Z-3-phenyl-2-benzoylpropenoic acid derivatives and tested their in vitro inhibitory activities on rat lens aldose reductase. Of these compounds, (Z-3-(3,4-dihydroxyphenyl-2-(4-methylbenzoylpropenoicacid(3k was identified as the most potent inhibitor, with an IC50 of 0.49μM. The theoretical binding mode of 3k was obtained by simulation of its docking into the active site of the human aldose reductase crystal structure.

  5. Sirtuins as Mediator of the Anti-Ageing Effects of Calorie Restriction in Skeletal and Cardiac Muscle

    Directory of Open Access Journals (Sweden)

    Alberto Zullo

    2018-03-01

    Full Text Available Fighting diseases and controlling the signs of ageing are the major goals of biomedicine. Sirtuins, enzymes with mainly deacetylating activity, could be pivotal targets of novel preventive and therapeutic strategies to reach such aims. Scientific proofs are accumulating in experimental models, but, to a minor extent, also in humans, that the ancient practice of calorie restriction could prove an effective way to prevent several degenerative diseases and to postpone the detrimental signs of ageing. In the present review, we summarize the evidence about the central role of sirtuins in mediating the beneficial effects of calorie restriction in skeletal and cardiac muscle since these tissues are greatly damaged by diseases and advancing years. Moreover, we entertain the possibility that the identification of sirtuin activators that mimic calorie restriction could provide the benefits without the inconvenience of this dietary style.

  6. Synthesis and biological evaluation of novel dioxa-bicycle C-aryl glucosides as SGLT2 inhibitors.

    Science.gov (United States)

    Yan, Qi; Ding, Ning; Li, Yingxia

    2016-02-08

    A series of novel C-aryl glucosides containing dioxa-bicycle were synthesized and evaluated for inhibition activity against hSGLT2. Among the compounds tested, compound 6a showed moderate SGLT2 inhibition activities at 700 nM. The results could benefit the discovery of new SGLT2 inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Novel Bifunctional Quinolonyl Diketo Acid Derivatives as HIV-1 Integrase Inhibitors: Design, Synthesis, Biological Activities and Mechanism of Action

    Science.gov (United States)

    Di Santo, Roberto; Costi, Roberta; Roux, Alessandra; Artico, Marino; Lavecchia, Antonio; Marinelli, Luciana; Novellino, Ettore; Palmisano, Lucia; Andreotti, Mauro; Amici, Roberta; Galluzzo, Clementina Maria; Nencioni, Lucia; Palamara, Anna Teresa; Pommier, Yves; Marchand, Christophe

    2008-01-01

    The virally encoded integrase protein is an essential enzyme in the life cycle of the HIV-1 virus and represents an attractive and validated target in the development of therapeutics against HIV infection. Drugs that selectively inhibit this enzyme, when used in combination with inhibitors of reverse transcriptase and protease, are believed to be highly effective in suppressing the viral replication. Among the HIV-1 integrase inhibitors, the β-diketo acids (DKAs) represent a major lead for anti-HIV-1drug development. In this study, novel bifunctional quinolonyl diketo acid derivatives were designed, synthesized and tested for their inhibitory ability against HIV-1 integrase. The compounds are potent inhibitors of integrase activity. Particularly, derivative 8 is a potent IN inhibitor for both steps of the reaction (3′-processing and strand transfer) and exhibits both high antiviral activity against HIV-1 infected cells and low cytotoxicity. Molecular modeling studies provide a plausible mechanism of action, which is consistent with ligand SARs and enzyme photo-crosslinking experiments. PMID:16539381

  8. Synthesis and antiproteasomal activity of novel O-benzyl salicylamide-based inhibitors built from leucine and phenylalanine

    Czech Academy of Sciences Publication Activity Database

    Jorda, Radek; Dušek, J.; Řezníčková, Eva; Pauk, K.; Magar, P. P.; Imramovský, A.; Kryštof, Vladimír

    2017-01-01

    Roč. 135, JUL 28 (2017), s. 142-158 ISSN 0223-5234 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Apoptosis * Inhibitor * Proteasome * Salicylamide * Ubiquitin Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemical research methods Impact factor: 4.519, year: 2016

  9. Design and synthesis of dual inhibitors of acetylcholinesterase and serotonin transporter targeting potential agents for Alzheimer's disease.

    Science.gov (United States)

    Kogen, Hiroshi; Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio

    2002-10-03

    Highly efficient acetylcholinesterase (AChE) and serotonin transporter (SERT) dual inhibitors, (S)-4 and (R)-13 were designed and synthesized on the basis of the hypothetical model of AChE active site. Both compounds showed potent inhibitory activities against AChE and SERT. [structure: see text

  10. New 5-benzylidenethiazolidin-4-one inhibitors of bacterial MurD ligase: design, synthesis, crystal structures, and biological evaluation.

    Science.gov (United States)

    Zidar, Nace; Tomašić, Tihomir; Šink, Roman; Kovač, Andreja; Patin, Delphine; Blanot, Didier; Contreras-Martel, Carlos; Dessen, Andréa; Premru, Manica Müller; Zega, Anamarija; Gobec, Stanislav; Mašič, Lucija Peterlin; Kikelj, Danijel

    2011-11-01

    Mur ligases (MurC-MurF), a group of bacterial enzymes that catalyze four consecutive steps in the formation of cytoplasmic peptidoglycan precursor, are becoming increasingly adopted as targets in antibacterial drug design. Based on the crystal structure of MurD cocrystallized with thiazolidine-2,4-dione inhibitor I, we have designed, synthesized, and evaluated a series of improved glutamic acid containing 5-benzylidenerhodanine and 5-benzylidenethiazolidine-2,4-dione inhibitors of MurD with IC(50) values up to 28 μM. Inhibitor 37, with an IC(50) of 34 μM, displays a weak antibacterial activity against S. aureus ATCC 29213 and E. faecalis ATCC 29212 with minimal inhibitory concentrations of 128 μg/mL. High-resolution crystal structures of MurD in complex with two new inhibitors (compounds 23 and 51) reveal details of their binding modes within the active site and provide valuable information for further structure-based optimization. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  11. Design and synthesis of N-(4-aminopyridin-2-yl)amides as B-Raf(V600E) inhibitors.

    Science.gov (United States)

    Li, Xiaokai; Shen, Jiayi; Tan, Li; Zhang, Zhang; Gao, Donglin; Luo, Jinfeng; Cheng, Huimin; Zhou, Xiaoping; Ma, Jie; Ding, Ke; Lu, Xiaoyun

    2016-06-15

    B-Raf(V600E) was an effective target for the treatment of human cancers. Based on a pan-Raf inhibitor TAK-632, a series of N-(4-aminopyridin-2-yl)amide derivatives were designed as novel B-Raf(V600E) inhibitors. Detailed structure-activity studies of the compounds revealed that most of the compounds displayed potent enzymatic activity against B-Raf(V600E), and good selectivity over B-Raf(WT). One of the most promising compound 4l exhibited potent inhibitory activity with an IC50 value of 38nM for B-raf(V600E), and displayed antiproliferative activities against colo205 and HT29 cells with IC50 values of 0.136 and 0.094μM, respectively. It also displayed good selectivity on both enzymatic and cellular assays over B-Raf(WT). These inhibitors may serve as lead compounds for further developing novel B-Raf(V600E) inhibitors as anticancer drugs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A Linker for the Solid-Phase Synthesis of Hydroxamic Acids and Identification of HDAC6 Inhibitors

    DEFF Research Database (Denmark)

    Bang, Claus Gunnar; Jensen, Jakob Feldthusen; Cohrt, Anders Emil O'Hanlon

    2017-01-01

    We herein present broadly useful, readily available and nonintegral hydroxylamine linkers for the routine solid-phase synthesis of hydroxamic acids. The developed protocols enable the efficient synthesis and release of a wide range of hydroxamic acids from various resins, relying on high control...... and flexibility with respect to reagents and synthetic processes. A trityl-based hydroxylamine linker was used to synthesize a library of peptide hydroxamic acids. The inhibitory effects of the compounds were examined for seven HDAC enzyme subtypes using a chemiluminescence-based assay....

  13. Synthesis, biological evaluation and molecular modeling of 2-Hydroxyisoquinoline-1,3-dione analogues as inhibitors of HIV reverse transcriptase associated ribonuclease H and polymerase.

    Science.gov (United States)

    Tang, Jing; Vernekar, Sanjeev Kumar V; Chen, Yue-Lei; Miller, Lena; Huber, Andrew D; Myshakina, Nataliya; Sarafianos, Stefan G; Parniak, Michael A; Wang, Zhengqiang

    2017-06-16

    Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) remains the only virally encoded enzymatic function not clinically validated as an antiviral target. 2-Hydroxyisoquinoline-1,3-dione (HID) is known to confer active site directed inhibition of divalent metal-dependent enzymatic functions, such as HIV RNase H, integrase (IN) and hepatitis C virus (HCV) NS5B polymerase. We report herein the synthesis and biochemical evaluation of a few C-5, C-6 or C-7 substituted HID subtypes as HIV RNase H inhibitors. Our data indicate that while some of these subtypes inhibited both the RNase H and polymerase (pol) functions of RT, potent and selective RNase H inhibition was achieved with subtypes 8-9 as exemplified with compounds 8c and 9c. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Synthesis of a wild-type and three mutant Cucurbita maxima trypsin inhibitor-encoding genes by a single-strand approach.

    Science.gov (United States)

    Botes, D P; Qobose, M D; Corfield, V A

    1991-09-15

    A single-strand approach to gene assembly, based on a modification of an in vitro complementary oligodeoxyribonucleotide template-directed ligation of the desired sequence to a linearized vector [Chen et al., Nucleic Acids Res. 18 (1990) 871-878], is described. The gene coding for the wild-type Cucurbita maxima trypsin inhibitor of 29 amino acid residues [Bode et al., FEBS Lett. 242 (1989) 285-292], as well as three mutant forms of the gene, in which two of the three disulfide bonds have been replaced singly or as a pair, have been synthesized in a single synthesis run with minimal manual intervention. Subsequent to ligation to pUC9 and in vivo gapped duplex repair by Escherichia coli, their sequences have been verified.

  15. Synthesis and modifications of heterocyclic derivatives of D-arabinose: potential inhibitors of glucose-6-phosphate isomerase and glucosamine-6-phosphate synthase

    International Nuclear Information System (INIS)

    Viana, Renato Marcio Ribeiro; Prado, Maria Auxiliadora Fontes; Alves, Ricardo Jose

    2008-01-01

    The synthesis of -5-(D-arabino-1,2,3,4-tetrahydroxybutyl)tetrazole and -2-(d-arabino-1,2,3,4-tetra-acetoxybutyl)-5-methyl-1,3,4-oxadiazole from d-arabinose is described. Attempts at removing the protecting groups of the oxadiazole derivative were unsuccessful, leading to products resulting from the opening of the oxadiazole ring. The unprotected tetrazole derivative was selectively phosphorylated at the primary hydroxyl group with diethyl phosphoryl chloride. The resulting 5-[d-arabino-4-(diethylphosphoryloxy)-1,2,3-trihydroxybutyl]tetrazole is a protected form of a potential inhibitor of the enzymes glucose-6-phosphate isomerase and glucosamine synthase. (author)

  16. Effect of nuclei acid synthesis inhibitors during irradiation and recovery of vegetative cells of the Bacillus Licheniforms irradiator with gamma quantums

    International Nuclear Information System (INIS)

    Padron, E.; Fernandez-Larrea, O.; Rios, F.; Manzano, J.

    1990-01-01

    Mitomycin C, Bruneomicine and Bleomicine are inhibitors antibiotics of the nucleic acids synthesis. Mitomycin C is and alkylated agent while Bruneomicine and Bleomicine cause single and bilateral breaks in DNA strands. The concentration, where 50% of the population growth rate is inhibited, are determined in these experiment. Such concentration were used during the work carried out. Dose-effect curves obtained during irradiation are not significantly different from the control when Bruneomicine and Mitomycin C are use. A viability increased, in presence of Mitomycin C and Bleomicine, is seen in a two-hour period during liquid-medium recovery (LER). The presence of Bruneomicine during recovery causes an increase of lethality. Taking into account the three compound studied, the results obtained in the case of Bleomicine and Mitomycin C agree with those found by other authors as they use other biological systems while in the case of Bruneomicine, it is described for the first time

  17. A Green Method for Synthesis of 7H-thiazolo[3,2-b][1,2, 4]-triazin-7-one Derivatives as AChE Inhibitors

    Directory of Open Access Journals (Sweden)

    Liu Sijie

    2015-01-01

    Full Text Available The authors study an efficient and green approach for the synthesis of 7H-thiazolo [3, 2-b][1,2,4]triazin-7-one derivatives as AChE inhibitors. The 7H-thiazolo[3,2-b][1,2,4]triazin-7-ones were designed by molecular docking, and readily prepared via a one-pot reaction in morpholine hydrosulfate ([Hnhm]HSO4 lonic liquid as the catalyst and solvent. The study of AChE inhibitory activity was carried out through using the Ellman colorimetric assay. The 7H-thiazolo[3,2-b][1,2,4]triazin-7-ones had been successfully synthesized by green catalyst. Most of the target compounds exhibited more than 50% inhibition at 10μM.

  18. Benzothiazole analogues: Synthesis, characterization, MO calculations with PM6 and DFT, in silico studies and in vitro antimalarial as DHFR inhibitors and antimicrobial activities.

    Science.gov (United States)

    Thakkar, Sampark S; Thakor, Parth; Ray, Arabinda; Doshi, Hiren; Thakkar, Vasudev R

    2017-10-15

    Benzothiazole analogues are of interest due to their potential activity against malarial and microbial infections. In search of suitable antimicrobial and antimalarial agents, we report here the synthesis, characterization and biological activities of benzothiazole analogues (J 1-J 10). The molecules were characterized by IR, Mass, 1 H NMR, 13 C NMR and elemental analysis. The in vitro antimicrobial activity was investigated against pathogenic strains; the results were explained with the help of DFT and PM6 molecular orbital calculations. In vitro cytotoxicity and genotoxicity of the molecules were studied against S. pombe cells. In vitro antimalarial activity was studied. The active compounds J 1, J 2, J 3, J 5 and J 6 were further evaluated for enzyme inhibition efficacy against the receptor Pf-DHFR, computational and in vitro studies were carried out to examine their candidatures as lead dihydrofolate reductase inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Pollination in Nicotiana alata stimulates synthesis and transfer to the stigmatic surface of NaStEP, a vacuolar Kunitz proteinase inhibitor homologue.

    Science.gov (United States)

    Busot, Grethel Yanet; McClure, Bruce; Ibarra-Sánchez, Claudia Patricia; Jiménez-Durán, Karina; Vázquez-Santana, Sonia; Cruz-García, Felipe

    2008-01-01

    After landing on a wet stigma, pollen grains hydrate and germination generally occurs. However, there is no certainty of the pollen tube growth through the style to reach the ovary. The pistil is a gatekeeper that evolved in many species to recognize and reject the self-pollen, avoiding endogamy and encouraging cross-pollination. However, recognition is a complex process, and specific factors are needed. Here the isolation and characterization of a stigma-specific protein from N. alata, NaStEP (N. alata Stigma Expressed Protein), that is homologous to Kunitz-type proteinase inhibitors, are reported. Activity gel assays showed that NaStEP is not a functional serine proteinase inhibitor. Immunohistochemical and protein blot analyses revealed that NaStEP is detectable in stigmas of self-incompatible (SI) species N. alata, N. forgetiana, and N. bonariensis, but not in self-compatible (SC) species N. tabacum, N. plumbaginifolia, N. benthamiana, N. longiflora, and N. glauca. NaStEP contains the vacuolar targeting sequence NPIVL, and immunocytochemistry experiments showed vacuolar localization in unpollinated stigmas. After self-pollination or pollination with pollen from the SC species N. tabacum or N. plumbaginifolia, NaStEP was also found in the stigmatic exudate. The synthesis and presence in the stigmatic exudate of this protein was strongly induced in N. alata following incompatible pollination with N. tabacum pollen. The transfer of NaStEP to the stigmatic exudate was accompanied by perforation of the stigmatic cell wall, which appeared to release the vacuolar contents to the apoplastic space. The increase in NaStEP synthesis after pollination and its presence in the stigmatic exudates suggest that this protein may play a role in the early pollen-stigma interactions that regulate pollen tube growth in Nicotiana.

  20. Multipotent cholinesterase/monoamine oxidase inhibitors for the treatment of Alzheimer's disease: design, synthesis, biochemical evaluation, ADMET, molecular modeling, and QSAR analysis of novel donepezil-pyridyl hybrids.

    Science.gov (United States)

    Bautista-Aguilera, Oscar M; Esteban, Gerard; Chioua, Mourad; Nikolic, Katarina; Agbaba, Danica; Moraleda, Ignacio; Iriepa, Isabel; Soriano, Elena; Samadi, Abdelouahid; Unzeta, Mercedes; Marco-Contelles, José

    2014-01-01

    The design, synthesis, and biochemical evaluation of donepezil-pyridyl hybrids (DPHs) as multipotent cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors for the potential treatment of Alzheimer's disease (AD) is reported. The 3D-quantitative structure-activity relationship study was used to define 3D-pharmacophores for inhibition of MAO A/B, acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) enzymes and to design DPHs as novel multi-target drug candidates with potential impact in the therapy of AD. DPH14 (Electrophorus electricus AChE [EeAChE]: half maximal inhibitory concentration [IC50] =1.1±0.3 nM; equine butyrylcholinesterase [eqBuChE]: IC50 =600±80 nM) was 318-fold more potent for the inhibition of AChE, and 1.3-fold less potent for the inhibition of BuChE than the reference compound ASS234. DPH14 is a potent human recombinant BuChE (hBuChE) inhibitor, in the same range as DPH12 or DPH16, but 13.1-fold less potent than DPH15 for the inhibition of human recombinant AChE (hAChE). Compared with donepezil, DPH14 is almost equipotent for the inhibition of hAChE, and 8.8-fold more potent for hBuChE. Concerning human monoamine oxidase (hMAO) A inhibition, only DPH9 and 5 proved active, compound DPH9 being the most potent (IC50 [MAO A] =5,700±2,100 nM). For hMAO B, only DPHs 13 and 14 were moderate inhibitors, and compound DPH14 was the most potent (IC50 [MAO B] =3,950±940 nM). Molecular modeling of inhibitor DPH14 within EeAChE showed a binding mode with an extended conformation, interacting simultaneously with both catalytic and peripheral sites of EeAChE thanks to a linker of appropriate length. Absortion, distribution, metabolism, excretion and toxicity analysis showed that structures lacking phenyl-substituent show better druglikeness profiles; in particular, DPHs13-15 showed the most suitable absortion, distribution, metabolism, excretion and toxicity properties. Novel donepezil-pyridyl hybrid DPH14 is a potent, moderately selective h

  1. Glycosphingolipid synthesis inhibitor AMP-DNM lowers plasma cholesterol levels by promoting fecal cholesterol excretion without inhibiting cholesterol absorption

    NARCIS (Netherlands)

    Vrins, Carlos L. J.; Bietrix, Florence; Lombardo, Elisa; van Roomen, Cindy P. A. A.; Ottenhoff, Roelof; Overkleeft, Herman S.; Aerts, Johannes M.

    2012-01-01

    Inhibition of glycosphingolipid synthesis with iminosugar N-(5'-adamantane-1'-yl-methoxy)-pentyl-1-deoxynojirimycin (AMP-DNM) increases fecal neutral sterol output in mice. To investigate which pathways were involved in this increase, C57BI/6J mice were treated with AMP-DNM and/or ezetimibe. Fecal

  2. Using docking and alchemical free energy approach to determine the binding mechanism of eEF2K inhibitors and prioritizing the compound synthesis.

    Science.gov (United States)

    Wang, Qiantao; Edupuganti, Ramakrishna; Tavares, Clint D J; Dalby, Kevin N; Ren, Pengyu

    2015-01-01

    A-484954 is a known eEF2K inhibitor with submicromolar IC50 potency. However, the binding mechanism and the crystal structure of the kinase remains unknown. Here, we employ a homology eEF2K model, docking and alchemical free energy simulations to probe the binding mechanism of eEF2K, and in turn, guide the optimization of potential lead compounds. The inhibitor was docked into the ATP-binding site of a homology model first. Three different binding poses, hypothesis 1, 2, and 3, were obtained and subsequently applied to molecular dynamics (MD) based alchemical free energy simulations. The calculated relative binding free energy of the analogs of A-484954 using the binding pose of hypothesis 1 show a good correlation with the experimental IC50 values, yielding an r (2) coefficient of 0.96 after removing an outlier (compound 5). Calculations using another two poses show little correlation with experimental data, (r (2) of less than 0.5 with or without removing any outliers). Based on hypothesis 1, the calculated relative free energy suggests that bigger cyclic groups, at R1 e.g., cyclobutyl and cyclopentyl promote more favorable binding than smaller groups, such as cyclopropyl and hydrogen. Moreover, this study also demonstrates the ability of the alchemical free energy approach in combination with docking and homology modeling to prioritize compound synthesis. This can be an effective means of facilitating structure-based drug design when crystal structures are not available.

  3. Design, synthesis, and biological evaluation of 3-vinyl-quinoxalin-2(1H-one derivatives as novel antitumor inhibitors of FGFR1

    Directory of Open Access Journals (Sweden)

    Liu Z

    2016-05-01

    Full Text Available Zhiguo Liu,1,* Shufang Yu,1,* Di Chen,1 Guoliang Shen,1 Yu Wang,1 Leping Hou,2 Dan Lin,1 Jinsan Zhang,1 Faqing Ye1 1School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, 2Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: FGFR1 is well known as a molecular target in anticancer drug design. TKI258 plays an important role in RTK inhibitors. Utilizing TKI258 as a lead compound that contains a quinazolinone nucleus, we synthesized four series of 3-vinyl-quinoxalin-2(1H-one derivatives, a total of 27 compounds. We further evaluated these compounds for FGFR1 inhibition ability as well as cytotoxicity against four cancer cell lines (H460, B16-F10, Hela229, and Hct116 in vitro. Some compounds displayed good-to-excellent potency against the four tested cancer cell lines compared with TKI258. Structure–activity relationship analyses indicated that small substituents at the side chain of the 3-vinyl-quinoxalin-2(1H-one were more effective than large substituents. Lastly, we used molecular docking to obtain further insight into the interactions between the compounds and FGFR1. Keywords: FGFR1, synthesis, quinoxaline, antitumor activity, kinase inhibitor

  4. Synthesis and biological evaluation of glycogen synthase kinase 3 (GSK-3) inhibitors: an fast and atom efficient access to 1-aryl-3-benzylureas.

    Science.gov (United States)

    Monte, Fabio Lo; Kramer, Thomas; Boländer, Alexander; Plotkin, Batya; Eldar-Finkelman, Hagit; Fuertes, Ana; Dominguez, Juan; Schmidt, Boris

    2011-09-15

    The glycogen synthase kinase 3 (GSK-3) is implicated in multiple cellular processes and has been linked to the pathogenesis of Alzheimer's disease (AD). In the course of our research topic we synthesized a library of potent GSK-3 inhibitors. We utilized the urea scaffold present in the potent and highly selective GSK-3 inhibitor AR-A014418 (AstraZeneca). This moiety suits both (a) a convergent approach utilizing readily accessible building blocks and (b) a divergent approach based on a microwave heating assisted Suzuki coupling. We established a chromatography-free purification method to generate products with sufficient purity for the biological assays. The structure-activity relationship of the library provided the rationale for the synthesis of the benzothiazolylurea 66 (IC(50)=140 nM) and the pyridylurea 62 (IC(50)=98 nM), which displayed two to threefold enhanced activity versus the reference compound 18 (AR-A014418: IC(50)=330 nM) in our assays. Copyright © 2011. Published by Elsevier Ltd.

  5. Synthesis and Biological Assessment of Racemic Benzochromenopyrimidinimines as Antioxidant, Cholinesterase, and Aβ1-42 Aggregation Inhibitors for Alzheimer's Disease Therapy.

    Science.gov (United States)

    Dgachi, Youssef; Ismaili, Lhassane; Knez, Damijan; Benchekroun, Mohamed; Martin, Hélène; Szałaj, Natalia; Wehle, Sarah; Bautista-Aguilera, Oscar M; Luzet, Vincent; Bonnet, Alexandre; Malawska, Barbara; Gobec, Stanislav; Chioua, Mourad; Decker, Michael; Chabchoub, Fakher; Marco-Contelles, José

    2016-06-20

    Given the complex nature of Alzheimer's disease (AD), compounds that are able to simultaneously address two or more AD-associated targets show greater promise for development into drugs for AD therapy. Herein we report an efficient two-step synthesis and biological evaluation of new racemic benzochromene derivatives as antioxidants, inhibitors of cholinesterase and β-amyloid (Aβ1-42 ) aggregation. Based on the results of the primary screening, we identified 15-(3-methoxyphenyl)-9,11,12,15-tetrahydro-10H,14H-benzo[5,6]chromeno[2,3-d]pyrido[1,2-a]pyrimidin-14-imine (3 e) and 16-(3-methoxyphenyl)-9,10,11,12,13,16-hexahydro-15H-benzo[5',6']chromeno[2',3':4,5]pyrimido[1,2-a]azepin-15-imine (3 f) as new potential multitarget-directed ligands for AD therapy. Further in-depth biological analysis showed that compound 3 f is a good human acetylcholinesterase inhibitor [IC50 =(0.36±0.02) μm], has strong antioxidant activity (3.61 μmol Trolox equivalents), and moderate Aβ1-42 antiaggregating power (40.3 %). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Design and synthesis of 4'-((5-benzylidene-2,4-dioxothiazolidin-3-yl)methyl)biphenyl-2-carbonitrile analogs as bacterial peptide deformylase inhibitors.

    Science.gov (United States)

    Khan, Firoz A Kalam; Patil, Rajendra H; Shinde, Devanand B; Sangshetti, Jaiprakash N

    2016-12-01

    Herein, we report the synthesis and screening of 4'-((5-benzylidene-2,4-dioxothiazolidin-3-yl)methyl)biphenyl-2-carbonitrile analogs 11(a-j) as bacterial peptide deformylase (PDF) enzyme inhibitors. The compounds 11b (IC 50 value = 139.28 μm), 11g (IC 50 value = 136.18 μm), and 11h (IC 50 value = 131.65 μm) had shown good PDF inhibition activity. The compounds 11b (MIC range = 103.36-167.26 μg/mL), 11g (MIC range = 93.75-145.67 μg/mL), and 11h (MIC range = 63.61-126.63 μg/mL) had also shown potent antibacterial activity when compared with standard ampicillin (MIC range = 100.00-250.00 μg/mL). Thus, the active derivatives were not only PDF inhibitors but also efficient antibacterial agents. To gain more insight on the binding mode of the compounds with PDF enzyme, the synthesized compounds 11(a-j) were docked against PDF enzyme of Escherichia coli and compounds exhibited good binding properties. The results suggest that this class of compounds has potential for development and use in future as antibacterial drugs. © 2016 John Wiley & Sons A/S.

  7. DNA synthesis in HeLa cells and isolated nuclei after treatment with an inhibitor of spermidine synthesis, methyl glyoxal bis(guanylhydrazone).

    Science.gov (United States)

    Krokan, H; Eriksen, A

    1977-02-01

    Addition of methyl glyoxal bis(guanylhydrazone) to HeLa S3 suspension cultures resulted in increased putrescine levels and decreased spermidine and spermine levels preceding a drop in incorporation of [3H]thymidine, [3H]uridine and [14C]leucine into macromolecules. When putrescine, spermidine, spermine or cadaverine was added simultaneously with methyl glyoxal bis(guanylhydrazone), the drug had no detectable effect on the synthesis of macromolecules. In nuclei isolated from cells treated with methyl glyoxal bis(guanylhydrazone) the reduction in the rate of DNA synthesis was equal to the reduction of [3H]thymidine incorporation in the corresponding whole cells. The capability of the nuclei to synthesize DNA could not be restored by adding spermidine or spermine to the system in vitro. The rate of DNA chain elongation was only reduced slightly by methyl glyoxal bis(guanylhydrazone) indicating that decreased levels of spermidine and spermine lead to a decrease in the number of replication units active in DNA synthesis within each cell.

  8. Synthesis, characterization and metal coordination of a potential β-lactamase inhibitor: 5-Methyl-2-phenoxymethyl-3-H-imidazole-4-carboxylic acid (PIMA

    Directory of Open Access Journals (Sweden)

    Chiara Romagnoli

    2017-12-01

    Full Text Available Among relevant metal ions in biological systems, zinc and iron play a key role as active partners of the catalytic machinery. In particular, the inhibition of metal enzymes that are involved in physiological and pathological processes has been deeply investigated for the rational design of selective and efficient drugs based on chelators. Since imidazole histidine residue is one of the most versatile sites in proteins, especially in enzymes acting in the presence of metal ions as cofactors, in this work the synthesis and characterization of a new imidazole derivative, namely 5-methyl-2-phenoxymethyl-3-H-imidazole-4-carboxylic acid (PIMA is reported. PIMA was designed as metallo-β-lactamase inhibitor thanks to its similarity with penicillin V, a β-lactam antibiotic inactivated by metallo-β-lactamase, for which there are no commercially available inhibitors. The evaluation of PIMA coordinating ability toward iron, zinc, and gallium, these latter selected as a non-paramagnetic probe for iron, is performed by theoretical DFT calculations and in solution by experimental techniques, i.e. potentiometry, UV–vis and NMR spectroscopy. PIMA exhibits an efficient metal chelating ability; the prevailing species in physiological condition are ML3 for Fe3+ and Ga3+ and ML2 for Zn2+, in which chelation is due to deprotonated carboxylic oxygen and imidazole nitrogen in the N,O donor set. The demonstrated ability of PIMA to chelate zinc ion, combined with its structure similarity with penicillin V, supports further exploration of this imidazole-4-carboxylate as metallo-β-lactamase inhibitor.

  9. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Pasasa, Norman Vincent A., E-mail: npasasa@gmail.com; Bundjali, Bunbun; Wahyuningrum, Deana [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha No. 10 Bandung, Jawa Barat (Indonesia)

    2015-09-30

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR and {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.

  10. Synthesis of [11C]dapoxetine·HCl, a serotonin re-uptake inhibitor: biodistribution in rat and preliminary PET imaging in the monkey

    International Nuclear Information System (INIS)

    Livni, E.; Satterlee, W.; Robey, R.L.

    1994-01-01

    [ 11 C]Dapoxetine · HCl, S-(+)-N,N-dimethyl-a-[2-(naphthalenyloxy)ethyl] benzenemethanamine hydrochloride, a potent serotonin re-uptake inhibitor was prepared from its mono-methyl precursor, S-(+)-N-methyl-a-[2-(naphthalenyloxy)ethyl]benzene methanamine hydrochloride. Biodistribution was determined in rats at 5, 30 and 60 min after injection and preliminary PET studies were performed in a Rhesus monkey. 11 CH 3 I was bubbled into a solution of S-(+)-N-methyl-α-[2-(naphthalenyloxy)ethyl]benzene methanamine hydrochloride (3.0 mg in DMSO) and the mixture was heated at 110 o C for 8 min. [ 11 C]Dapoxetine · HCl was purified by HPLC on a C 18 cartridge eluted with MeOH: phosphate buffer, pH 7.2 (75:25) with a 10% yield (end of synthesis). The time required for the synthesis was 40 min, from the end of bombardment. Radiochemical purity of the final product was > 99% and specific activity was routinely > 400 mCi/μmol [EOS]. (author)

  11. Design and Synthesis of Novel and Selective Glycine Transporter-1 (GlyT1) Inhibitors with Memory Enhancing Properties.

    Science.gov (United States)

    Santora, Vincent J; Almos, Theresa A; Barido, Richard; Basinger, Jillian; Bellows, Chris L; Bookser, Brett Carder; Breitenbucher, J Guy; Broadbent, Nicola J; Cabebe, Clifford; Chai, Chih-Kun; Chen, Mi; Chow, Stephine; Chung, De Michael; Crickard, Lindsay; Danks, Anne M; Freestone, Graeme; Gitnick, Dany; Gupta, Varsha; Hoffmaster, Christine; Hudson, Andrew R; Kaplan, Alan P; Kennedy, Michael R; Lee, Dong; Limberis, James; Ly, Kiev; Mak, Chi Ching; Masatsugu, Brittany; Morse, Andrew C; Na, Jim; Neul, David; Nikpur, John; Peters, Marco; Petroski, Robert E; Renick, Joel; Sebring, Kristen; Sevidal, Samantha; Tabatabaei, Ali; Wen, Jenny; Yan, Yingzhuo; Yoder, Zachary W; Zook, Douglas

    2018-06-11

    We report here the identification and optimization of a novel series of potent GlyT1 inhibitors. A ligand design campaign that utilized known GlyT1 inhibitors as starting points led to the identification of a novel series of pyrrolo[3,4-c]pyrazoles amides (21-50) with good in vitro potency. Subsequent optimization of physicochemical and in vitro ADME properties produced several compounds with promising pharmacokinetic profiles. In vivo inhibition of GlyT1 was demonstrated for select compounds within this series by measuring the elevation of glycine in the cerebrospinal fluid (CSF) of rats after a single oral dosing of 10 mg/kg. Ultimately, an optimized lead, compound 46, demonstrated in vivo efficacy in a rat Novel Object Recognition (NOR) assay after oral dosing at 0.1, 1, and 3 mg/kg.

  12. Exploration of mild copper-mediated coupling of organotrifluoroborates in the synthesis of thiirane-based inhibitors of matrix metalloproteinases.

    Science.gov (United States)

    Testero, Sebastian A; Bouley, Renee; Fisher, Jed F; Chang, Mayland; Mobashery, Shahriar

    2011-05-01

    The copper-mediated and non-basic oxidative cross-coupling of organotrifluoroborates with phenols was applied to elaboration of the structures of thiirane-based inhibitors of matrix metalloproteinases. By revision of the synthetic sequence to allow this cross-coupling as the final step, and taking advantage of the neutral nature of organotrifluoroborate cross-coupling, a focussed series of inhibitors showing aryloxy and alkenyloxy replacement of the phenoxy substituent was prepared. This reaction shows exceptional promise as an alternative to the classic copper-mediated but strongly basic Ullmann reaction, for the diversification of ether segments within base-labile lead structures. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Discovery of imidazopyridine derivatives as novel c-Met kinase inhibitors: Synthesis, SAR study, and biological activity.

    Science.gov (United States)

    Yang, Yifei; Zhang, Yuan; Yang, LingYun; Zhao, Leilei; Si, Lianghui; Zhang, Huibin; Liu, Qingsong; Zhou, Jinpei

    2017-02-01

    Receptor tyrosine kinase c-Met acts as an alternative angiogenic pathway in the process and contents of cancers. A series of imidazopyridine derivatives were designed and synthesized according to the established docking studies as possible c-Met inhibitors. Most of these imidazopyridine derivatives displayed nanomolar potency against c-Met in both biochemical enzymatic screens and cellular pharmacology studies. Especially, compound 7g exhibited the most inhibitory activity against c-Met with IC 50 of 53.4nM and 253nM in enzymatic and cellular level, respectively. Following that, the compound 7g was docked into the protein of c-Met and the structure-activity relationship was analyzed in detail. These findings indicated that the novel imidazopyridine derivative compound 7g was a potential c-Met inhibitor deserving further investigation for cancer treatment. Copyright © 2016. Published by Elsevier Inc.

  14. Synthesis of a dansyl-labeled inhibitor of 17β-hydroxysteroid dehydrogenase type 3 for optical imaging.

    Science.gov (United States)

    Kenmogne, Lucie Carolle; Maltais, René; Poirier, Donald

    2016-05-01

    The steroidogenic enzyme 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3) is a therapeutic target in the management of androgen-sensitive diseases such as prostate cancer and benign prostate hyperplasia. In this Letter, we designed and synthesized the first fluorescent inhibitor of this enzyme by combining a fluorogenic dansyl moiety to the chemical structure of a known inhibitor of 17β-HSD3. The synthesized compound 3 is a potent fluorogenic compound (λex=348 nm and λ em=498 nm). It crosses the cell membrane, keeps its fluorescent properties and is distributed inside the LNCaP cells overexpressing 17β-HSD3, where it inhibits the transformation of 4-androstene-3,17-dione into the androgen testosterone (IC50=262 nM). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Design and synthesis of prostate cancer antigen-1 (PCA-1/ALKBH3) inhibitors as anti-prostate cancer drugs.

    Science.gov (United States)

    Nakao, Syuhei; Mabuchi, Miyuki; Shimizu, Tadashi; Itoh, Yoshihiro; Takeuchi, Yuko; Ueda, Masahiro; Mizuno, Hiroaki; Shigi, Naoko; Ohshio, Ikumi; Jinguji, Kentaro; Ueda, Yuko; Yamamoto, Masatatsu; Furukawa, Tatsuhiko; Aoki, Shunji; Tsujikawa, Kazutake; Tanaka, Akito

    2014-02-15

    A series of 1-aryl-3,4-substituted-1H-pyrazol-5-ol derivatives was synthesized and evaluated as prostate cancer antigen-1 (PCA-1/ALKBH3) inhibitors to obtain a novel anti-prostate cancer drug. After modifying 1-(1H-benzimidazol-2-yl)-3,4-dimethyl-1H-pyrazol-5-ol (1), a hit compound found during random screening using a recombinant PCA-1/ALKBH3, 1-(1H-5-methylbenzimidazol-2-yl)-4-benzyl-3-methyl-1H-pyrazol-5-ol (35, HUHS015), was obtained as a potent PCA-1/ALKBH3 inhibitor both in vitro and in vivo. The bioavailability (BA) of 35 was 7.2% in rats after oral administration. As expected, continuously administering 35 significantly suppressed the growth of DU145 cells, which are human hormone-independent prostate cancer cells, in a mouse xenograft model without untoward effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Design, synthesis and biological evaluation of LBM-A5 derivatives as potent P-glycoprotein-mediated multidrug resistance inhibitors.

    Science.gov (United States)

    Wu, Yuxiang; Pan, Miaobo; Dai, Yuxuan; Liu, Baomin; Cui, Jian; Shi, Wei; Qiu, Qianqian; Huang, Wenlong; Qian, Hai

    2016-05-15

    A novel series of P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) inhibitors with triazol-N-phenethyl-tetrahydroisoquinoline or triazol-N-ethyl-tetrahydroisoquinoline scaffold were designed and synthesized via click chemistry. Most of the synthesized compounds showed higher reversal activity than verapamil (VRP). Among them, the most potent compound 4 showed a comparable activity with the known potent P-gp inhibitor WK-X-34 with lower cytotoxicity toward K562 cells (IC50>100μM). Compared with VRP, compound 4 exhibited more potency in increasing drug accumulation in K562/A02 MDR cells. Moreover, compound 4 could significantly reverse MDR in a dose-dependent manner and also persist longer chemo-sensitizing effect than VRP with reversibility. Further mechanism studies revealed that compound 4 could remarkably increase the intracellular accumulation of Adriamycin (ADM) in K562/A02 cells as well as inhibit rhodamine-123 (Rh123) efflux from the cells. These results suggested that compound 4 may represent a promising candidate for developing P-gp-mediated MDR inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 2-nitrobenzohydrazide as a potent urease inhibitor: synthesis, characterization and single crystal x-ray diffraction analysis

    International Nuclear Information System (INIS)

    Abbas, N.; Khan, I.; Hameed, S.; Batool, S.

    2018-01-01

    2-Nitrobenzohydrazide was efficiently synthesized in two steps by the esterification of 2-nitrobenzoic acid followed by the treatment with hydrazine hydrate in methanol. The structure of 2-nitrobenzohydrazide was established by modern spectro-analytical techniques including FTIR, 1H and 13C-NMR spectroscopy and unequivocally confirmed by single crystal X-ray diffraction data. 2-Nitrobenzohydrazide crystallized in orthorhombic space group P 21 21 21 with unit cell dimensions a = 4.9764(4) Å, b = 12.5280 (3) Å, c = 12.8512(1) Å, α = β = γ = 90°. A combination of N‒H…N and N‒H…O hydrogen bonds stabilized the crystal packing of 3. The synthesized compound 3 was assessed as urease inhibitor against Jack bean urease and the results revealed good inhibitory potency with an IC50 value of 4.25 ± 0.08 µM. This inhibition strength was 5-fold higher compared to the reference inhibitor thiourea (IC50 = 21.00 ± 0.11 µM). The molecular docking studies of the synthesized inhibitor 3 inside the active pocket of urease revealed several important binding interactions. (author)

  18. Synthesis, pharmacology and molecular docking on multifunctional tacrine-ferulic acid hybrids as cholinesterase inhibitors against Alzheimer's disease.

    Science.gov (United States)

    Zhu, Jie; Yang, Hongyu; Chen, Yao; Lin, Hongzhi; Li, Qi; Mo, Jun; Bian, Yaoyao; Pei, Yuqiong; Sun, Haopeng

    2018-12-01

    The cholinergic hypothesis has long been a "polar star" in drug discovery for Alzheimer's disease (AD), resulting in many small molecules and biological drug candidates. Most of the drugs marketed for AD are cholinergic. Herein, we report our efforts in the discovery of cholinesterases inhibitors (ChEIs) as multi-target-directed ligands. A series of tacrine-ferulic acid hybrids have been designed and synthesised. All these compounds showed potent acetyl-(AChE) and butyryl cholinesterase(BuChE) inhibition. Among them, the optimal compound 10g, was the most potent inhibitor against AChE (electrophorus electricus (eeAChE) half maximal inhibitory concentration (IC 50 ) = 37.02 nM), it was also a strong inhibitor against BuChE (equine serum (eqBuChE) IC 50  = 101.40 nM). Besides, it inhibited amyloid β-protein self-aggregation by 65.49% at 25 μM. In subsequent in vivo scopolamine-induced AD models, compound 10g obviously ameliorated the cognition impairment and showed preliminary safety in hepatotoxicity evaluation. These data suggest compound 10g as a promising multifunctional agent in the drug discovery process against AD.

  19. Design, synthesis and evaluation of novel tacrine-coumarin hybrids as multifunctional cholinesterase inhibitors against Alzheimer's disease.

    Science.gov (United States)

    Xie, Sai-Sai; Wang, Xiao-Bing; Li, Jiang-Yan; Yang, Lei; Kong, Ling-Yi

    2013-06-01

    A series of tacrine-coumarin hybrids (8a-t) were designed, synthesized and evaluated as multifunctional cholinesterase (ChE) inhibitors against Alzheimer's disease (AD). The screening results showed that most of them exhibited a significant ability to inhibit ChE and self-induced β-amyloid (Aβ) aggregation, and to act as metal chelators. Especially, 8f displayed the greatest ability to inhibit acetylcholinesterase (AChE, IC50 = 0.092 μM) and Aβ aggregation (67.8%, 20 μM). It was also a good butyrylcholinesterase inhibitor (BuChE, IC50 = 0.234 μM) and metal chelator. Besides, kinetic and molecular modeling studies indicated that 8f was a mixed-type inhibitor, binding simultaneously to active, peripheral and mid-gorge sites of AChE. These results suggested that 8f might be an excellent multifunctional agent for AD treatment. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  20. Synthesis and biological evaluation of novel thiadiazole amides as potent Cdc25B and PTP1B inhibitors.

    Science.gov (United States)

    Li, Yingjun; Yu, Yang; Jin, Kun; Gao, Lixin; Luo, Tongchuan; Sheng, Li; Shao, Xin; Li, Jia

    2014-09-01

    A series of novel thiadiazole amide derivatives have been synthesized and evaluated for inhibitory activities against Cdc25B and PTP1B. Most of them showed inhibitory activities against Cdc25B (IC50=1.18-8.01 μg/mL) and PTP1B (IC50=0.85-8.75 μg/mL), respectively. Moreover, compounds 5b and 4l were most potent with IC50 values of 1.18 and 0.85 μg/mL for Cdc25B and PTP1B, respectively, compared with reference drugs Na3VO4 (IC50=0.93 μg/mL) and oleanolic acid (IC50=0.85 μg/mL). The results of selectivity experiments showed that the target compounds were selective inhibitors against PTP1B and Cdc25B. Enzyme kinetic experiments demonstrated that compound 5k was a specific inhibitor with the typical characteristics of a mixed inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Design, synthesis, and biological evaluation of resveratrol analogues as aromatase and quinone reductase 2 inhibitors for chemoprevention of cancer

    International Nuclear Information System (INIS)

    Sun, Bin; Hoshino, Juma; Jermihov, Katie; Marler, Laura; Pezzuto, John M.; Mesecar, Andrew D.; Cushman, Mark

    2010-01-01

    A series of new resveratrol analogues were designed and synthesized and their inhibitory activities against aromatase were evaluated. The crystal structure of human aromatase (PDB 3eqm) was used to rationalize the mechanism of action of the aromatase inhibitor 32 (IC 50 0.59 μM) through docking, molecular mechanics energy minimization, and computer graphics molecular modeling, and the information was utilized to design several very potent inhibitors, including compounds 82 (IC 50 70 nM) and 84 (IC 50 36 nM). The aromatase inhibitory activities of these compounds are much more potent than that for the lead compound resveratrol, which has an IC 50 of 80 μM. In addition to aromatase inhibitory activity, compounds 32 and 44 also displayed potent QR2 inhibitory activity (IC 50 1.7 μM and 0.27 μM, respectively) and the high-resolution X-ray structures of QR2 in complex with these two compounds provide insight into their mechanism of QR2 inhibition. The aromatase and quinone reductase inhibitors resulting from these studies have potential value in the treatment and prevention of cancer.

  2. Sirtuin 1 independent effects of resveratrol in INS-1E β-cells

    DEFF Research Database (Denmark)

    Erdogan, Cihan Süleyman; Mørup-Lendal, Mathias; Dalgaard, Louise Torp

    2017-01-01

    Resveratrol (Resv), a natural polyphenol, is suggested to have various health benefits including improved insulin sensitivity. Resv activates Sirtuin (Sirt1) in several species and tissues. Sirt1 is a protein deacetylase with an important role in ageing, metabolism and β-cell function. In insulin......Resveratrol (Resv), a natural polyphenol, is suggested to have various health benefits including improved insulin sensitivity. Resv activates Sirtuin (Sirt1) in several species and tissues. Sirt1 is a protein deacetylase with an important role in ageing, metabolism and β-cell function...... effects of Resv with respect to mTOR cascade activity. Sirt1-knockdown (KD) had a significant increase in cell size compared to negative-control (NEG CTR) cells. Resveratrol treatment increased cell size in both cell types in a dose-dependent manner at 24 h (Resv conc: 15-60 μM), and decreased the cell...... not affect the mTOR cascade activities as measured by Western blotting for total and phosphorylated Akt and mTOR. Rapamycin decreased the mTORC1 activity, while increasing the pAkt levels. Resveratrol did not interfere with the mTOR activity or with Sirt1 expression. Altogether, this work indicates that Sirt...

  3. Differences in Sirtuin Regulation in Response to Calorie Restriction in Cryptococcus neoformans.

    Science.gov (United States)

    Bouklas, Tejas; Masone, Lindsey; Fries, Bettina C

    2018-02-18

    Cryptococcus neoformans successfully replicates in low glucose in infected patients. In the serotype A strain, H99, growth in this condition prolongs lifespan regulated by SIR2, and can be modulated with SIR2-specific drugs. Previous studies show that lifespan modulation of a cryptococcal population affects its sensitivity to antifungals, and survival in an infection model. Sirtuins and their role in longevity are conserved among fungi; however, the effect of glucose starvation is not confirmed even in Saccharomyces cerevisiae. Lifespan analysis of C. neoformans strains in low glucose showed that 37.5% exhibited pro-longevity, and lifespan of a serotype D strain, RC2, was shortened. Transcriptome comparison of H99 and RC2 under calorie restriction demonstrated differences, confirmed by real-time PCR showing that SIR2 , TOR1 , SCH9 , and PKA1 expression correlated with lifespan response to calorie restriction. As expected, RC2 -sir2 Δ cells exhibited a shortened lifespan, which was reconstituted. However, shortened lifespan from calorie restriction was independent of SIR2 . In contrast to H99 but consistent with altered SIR2 regulation, SIR2 -specific drugs did not affect outcome of RC2 infection. These data suggest that SIR2 regulation and response to calorie restriction varies in C. neoformans, which should be considered when Sirtuins are investigated as potential therapy targets for fungal infections.

  4. Sirtuin 1 Agonist Minimizes Injury and Improves the Immune Response Following Traumatic Shock.

    Science.gov (United States)

    Luciano, Jason A; Kautza, Benjamin; Darwiche, Sophie; Martinez, Silvia; Stratimirovic, Sladjana; Waltz, Paul; Sperry, Jason; Rosengart, Matthew; Shiva, Sruti; Zuckerbraun, Brian S

    2015-08-01

    Survival from traumatic injury requires a coordinated and controlled inflammatory and immune response. Mitochondrial and metabolic responses to stress have been shown to play a role in these inflammatory and immune responses. We hypothesized that increases in mitochondrial biogenesis via a sirtuin 1 agonist would decrease tissue injury and partially ameliorate the immunosuppression seen following trauma. C57Bl/6 mice were subjected to a multiple trauma model. Mice were pretreated with either 100 mg/kg per day of the sirtuin 1 agonist, Srt1720, via oral gavage for 2 days prior to trauma and extended until the day the animals were killed, or they were pretreated with peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) siRNA via hydrodynamic tail vein injection 48 h prior to trauma. Markers for mitochondrial function and biogenesis were measured in addition to splenocyte proliferative capacity and bacterial clearance. Srt1720 was noted to improve mitochondrial biogenesis, mitochondrial function, and complex IV activity following traumatic injury (P hepatic injury with significant reductions in serum alanine aminotransferase levels seen in mice treated with srt1720. Splenocyte proliferative capacity and intraperitoneal bacterial clearance were evaluated as markers for overall immune function following trauma-hemorrhage. Treatment with Srt1720 minimized the trauma-induced decreases in splenocyte proliferation (P clearance. The PGC1α signaling pathway is an important regulator of mitochondrial function and biogenesis, which can potentially be harnessed to protect against hepatic injury and minimize the immunosuppression that is seen following trauma-hemorrhage.

  5. Effects of niacin restriction on sirtuin and PARP responses to photodamage in human skin.

    Directory of Open Access Journals (Sweden)

    Claudia A Benavente

    Full Text Available Sirtuins (SIRTs and poly(ADP-ribose polymerases (PARPs, NAD(+-dependent enzymes, link cellular energy status with responses to environmental stresses. Skin is frequently exposed to the DNA damaging effects of UV irradiation, a known etiology in skin cancer. Thus, understanding the defense mechanisms in response to UV, including the role of SIRTs and PARPs, may be important in developing skin cancer prevention strategies. Here, we report expression of the seven SIRT family members in human skin. SIRTs gene expressions are progressively upregulated in A431 epidermoid carcinoma cells (SIRTs1 and 3, actinic keratoses (SIRTs 2, 3, 5, 6, and 7 and squamous cell carcinoma (SIRTs 1-7. Photodamage induces dynamic changes in SIRT expression with upregulation of both SIRT1 and SIRT4 mRNAs. Specific losses of SIRT proteins occur early after photodamage followed by accumulation later, especially for SIRT4. Niacin restriction, which decreases NAD(+, the sirtuin substrate, results in an increase in acetylated proteins, upregulation of SIRTs 2 and 4, increased inherent DNA damage, alterations in SIRT responses to photodamage, abrogation of PARP activation following photodamage, and increased sensitivity to photodamage that is completely reversed by repleting niacin. These data support the hypothesis that SIRTs and PARPs play important roles in resistance to photodamage and identify specific SIRTs that respond to photodamage and may be targets for skin cancer prevention.

  6. Resveratrol Protects against TNF-α-Induced Injury in Human Umbilical Endothelial Cells through Promoting Sirtuin-1-Induced Repression of NF-KB and p38 MAPK

    Science.gov (United States)

    Huang, Shujie; Zhu, Pengli

    2016-01-01

    Inflammation and reactive oxygen species (ROS) play important roles in the pathogenesis of atherosclerosis. Resveratrol has been shown to possess anti-inflammatory and antioxidative stress activities, but the underlying mechanisms are not fully understood. In the present study, we investigated the molecular basis associated with the protective effects of resveratrol on tumor necrosis factor-alpha (TNF-α)-induced injury in human umbilical endothelial cells (HUVECs) using a variety of approaches including a cell viability assay, reverse transcription and quantitative polymerase chain reaction, western blot, and immunofluorescence staining. We showed that TNF-α induced CD40 expression and ROS production in cultured HUVECs, which were attenuated by resveratrol treatment. Also, resveratrol increased the expression of sirtuin 1 (SIRT1); and repression of SIRT1 by small-interfering RNA (siRNA) and the SIRT1 inhibitor Ex527 reduced the inhibitory effects of resveratrol on CD40 expression and ROS generation. In addition, resveratrol downregulated the levels of p65 and phospho-p38 MAPK, but this inhibitory effect was attenuated by the suppression of SIRT1 activity. Moreover, the p38 MAPK inhibitor SD203580 and the nuclear factor (NF)-κB inhibitor pyrrolidine dithiocarbamate (PDTC) achieved similar repressive effects as resveratrol on TNF-α-induced ROS generation and CD40 expression. Thus, our study provides a mechanistic link between resveratrol and the activation of SIRT1, the latter of which is involved in resveratrol-mediated repression of the p38 MAPK/NF-κB pathway and ROS production in TNF-α-treated HUVECs. PMID:26799794

  7. Synthesis and activity of novel analogs of hemiasterlin as inhibitors of tubulin polymerization: modification of the A segment.

    Science.gov (United States)

    Yamashita, Ayako; Norton, Emily B; Kaplan, Joshua A; Niu, Chuan; Loganzo, Frank; Hernandez, Richard; Beyer, Carl F; Annable, Tami; Musto, Sylvia; Discafani, Carolyn; Zask, Arie; Ayral-Kaloustian, Semiramis

    2004-11-01

    Analogs of hemiasterlin (1) and HTI-286 (2), which contain various aromatic rings in the A segment, were synthesized as potential inhibitors of tubulin polymerization. The structure-activity relationships related to stereo- and regio-chemical effects of substituents on the aromatic ring in the A segment were studied. Analogs, which carry a meta-substituted phenyl ring in the A segment show comparable activity for inhibition of tubulin polymerization to 2, as well as in the cell proliferation assay using KB cells containing P-glycoprotein, compared to those of 1 and 2.

  8. Design, Synthesis and Biological Evaluation of 1,4-Disubstituted-3,4-dihydroisoquinoline Compounds as New Tubulin Polymerization Inhibitors

    Directory of Open Access Journals (Sweden)

    Ling Zhang

    2015-05-01

    Full Text Available A series of 1,4-disubstituted-3,4-dihydroisoquinoline derivatives designed as tubulin polymerization inhibitors were synthesized. Their cytotoxic activities against the CEM leukemia cell line were evaluated. Most of them displayed moderate cytotoxic activities, and compounds 21 and 32 showed good activities with IC50 of 4.10 and 0.64 μM, respectively. The most potent compound 32 was further confirmed to be able to inhibit tubulin polymerization, and its hypothetical binding mode with tubulin was obtained by molecular docking.

  9. Design, synthesis, molecular modeling and biological evaluation of novel diaryl heterocyclic analogs as potential selective cyclooxygenase-2 (COX-2 inhibitors

    Directory of Open Access Journals (Sweden)

    Deema A. Al-Turki

    2017-01-01

    Full Text Available New series of 3,4-diaryl-2-thioxoimidazolidin-4-ones and 3-alkylthio-4,5-diaryl-4H-1,2,4-triazoles were designed, synthesized and evaluated for their activity as anti-inflammatory agents. Compounds 20, 21, 23 and 34 are highly selective inhibitors of COX-2 enzyme at a concentration of 100 mM relative to celecoxib, the standard reference. (±-3-(4-Phenoxy-phenyl-5-phenyl-2-thioxoimidazolidin-4-ones 23 exhibited the most active anti-inflammatory agent.

  10. Fibre autoradiography of repair and replication in DNA from single cells: the effect of DNA synthesis inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Ockey, C.H.

    1982-04-01

    DNA fibre autoradiography, after incorporation of high specific activity /sup 3/H-thymidine and /sup 3/H-deoxycytidine, has been used to investigate repair in DNA fibres from single cells following UV, or methyl-methane sulphonate (MMS) treatment. Asynchronously growing human fibroblasts, leucocytes, and HeLa cells at different phases of the cell cycle have been investigated. Isotope incorporation in repair could be differentiated from that involved in replication by the distribution and density of silver grains along the DNA fibres. Grain distribution due to repair was continuous over long stretches of the fibres and was at a low density, occasionally interspersed with short slightly denser segments. Replication labelling on the other hand, was dense and usually in short tandem segments. Repair labelling was of a similar overall density in fibres from a single cell, but differed in intensity from cell to cell. In mutagen treated Go (leucocytes) of G/sub 1/ (HeLa cells), repair labelling was not increased by the presence of the DNA inhibitors, hydroxyurea (HU) or 5-fluorodeoxyuridine (FUdR). Repair was not detectable in S cells however without the use of these inhibitors to reduce endogenous nucleoside production. FUdR enhanced the repair labelling in S cells only slightly, while HU increased it beyond that observed in UV irradiated, HU treated, G/sub 1/ cells. The intensity of repair labelling in fibres from mutagen treated S cells appears to be proportional to the degree of reduction of DNA chain elongation in replicons.

  11. Synthesis and evaluation of new long alkyl side chain acetamide, isoxazolidine and isoxazoline derivatives as corrosion inhibitors

    International Nuclear Information System (INIS)

    Yildirim, A.; Cetin, M.

    2008-01-01

    2-(Alkylsulfanyl)-N-(pyridin-2-yl) acetamide derivatives were synthesized via amidation reaction of acyl chlorides bearing S atom in the long chain with 2-aminopyridine. Derivatives of isoxazolidine and isoxazoline were synthesized through 1,3-dipolar cycloaddition reactions with three different long chain alkenes containing O or S as hetero atoms and C,N-diphenyl nitrone or benzonitrile-N-oxide, respectively. Synthesized compounds were characterized with their FT-IR, 1 H NMR spectra and then their physical properties and corrosion prevention efficiencies were investigated. All compounds were tested with steel coupons in acidic medium by gravimetric method, and also some of them were tested with steel stripe in paraffin based mineral oil medium via standard method. Acidic test was done with a medium concentration of 2 M HCl for 20 h at room temperature. Mineral oil was used and the test in this medium was done at 60 deg. C constant temperature but varying time from 42 to 63 h. The best inhibition was generally obtained at 50 ppm inhibitor concentration in the acidic medium. All tested inhibitors except two of them in oil medium also showed promising inhibition efficiencies

  12. Cyclohex-1-ene carboxylic acids: synthesis and biological evaluation of novel inhibitors of human 5 alpha reductase.

    Science.gov (United States)

    Baston, Eckhard; Salem, Ola I A; Hartmann, Rolf W

    2003-03-01

    In search of novel nonsteroidal mimics of steroidal inhibitors of 5 alpha reductase, 4-(2-phenylethyl)cyclohex-1-ene carboxylic acids 1-5 were synthesized with different substituents in para position of the phenyl ring (1: N, N-diisopropylcarbamoyl, 2: phenyl, 3: phenoxy, 4: benzoyl, and 5: benzyl). The principal synthetic approach for the desired compounds consisted of a Wittig olefination between 1, 4-dioxaspiro [4.5]-decane-8-carbaldehyde (4g and the appropriate phosphonium salts. The compounds were tested for inhibition of human 5 alpha reductase isozymes 1 and 2 using DU 145 cells and preparations from prostatic tissue, respectively. They turned out to be good inhibitors of the prostatic isozyme 2 with compound 1 being the most potent one (IC(50) = 760 nM). Isozyme 1 was only slightly inhibited. It is concluded that the novel structures are appropriate for being further optimized, aiming at the development of a novel drug for the treatment of benign prostatic hyperplasia.

  13. Catecholic amides as potential selective phosphodiesterase 4D inhibitors: Design, synthesis, pharmacological evaluation and structure-activity relationships.

    Science.gov (United States)

    Zhou, Zhong-Zhen; Ge, Bing-Chen; Chen, Yu-Fang; Shi, Xiu-Dong; Yang, Xue-Mei; Xu, Jiang-Ping

    2015-11-15

    In this study, a series of catechol-based amides (8a-n) with different amide linkers linking the catecholic moiety to the terminal phenyl ring was designed and synthesized as potent phosphodiesterase (PDE) 4D inhibitors. The inhibitory activities of these compounds were evaluated against the core catalytic domains of human PDE4 (PDE4CAT), full-length PDE4B1 and PDE4D7 enzymes, and other PDE family members. The results indicated the majority of compounds 8a-n displayed moderate to good inhibitory activities against PDE4CAT. Among these compounds, compound 8 j with a short amide linker (-CONHCH2-) displayed comparable PDE4CAT inhibitory activity (IC50=410 nM) with rolipram. More interestingly, compound 8 g, a potent and selective PDE4D inhibitor (IC50=94 nM), exhibited a 10-fold selectivity over the PDE4B subtypes and an over 1000-fold selectivity against other PDE family members. Docking simulations suggested that 8 g forms three extra H-bonds with the N-H of residue Asn487 and two water molecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death

    Energy Technology Data Exchange (ETDEWEB)

    Guida, Natascia [IRCSS SDN, Naples 80131 (Italy); Laudati, Giusy [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Anzilotti, Serenella [IRCSS SDN, Naples 80131 (Italy); Secondo, Agnese [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Montuori, Paolo [Department of Public Health, ‘Federico II’ University of Naples, Naples (Italy); Di Renzo, Gianfranco [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Canzoniero, Lorella M.T. [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy); Formisano, Luigi, E-mail: cformisa@unisannio.it [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy)

    2015-11-01

    Resveratrol (3,5,4′-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. - Highlights: • Resveratrol via SIRT1/c-Jun downregulates REST mRNA and protein in SH-SY5Y cells. • Non-dioxin-like (NDL) PCB-95 is cytotoxic to

  15. Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death

    International Nuclear Information System (INIS)

    Guida, Natascia; Laudati, Giusy; Anzilotti, Serenella; Secondo, Agnese; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M.T.; Formisano, Luigi

    2015-01-01

    Resveratrol (3,5,4′-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. - Highlights: • Resveratrol via SIRT1/c-Jun downregulates REST mRNA and protein in SH-SY5Y cells. • Non-dioxin-like (NDL) PCB-95 is cytotoxic to

  16. Opposing effects of sirtuins on neuronal survival: SIRT1-mediated neuroprotection is independent of its deacetylase activity.

    Directory of Open Access Journals (Sweden)

    Jason A Pfister

    Full Text Available BACKGROUND: Growing evidence suggests that sirtuins, a family of seven distinct NAD-dependent enzymes, are involved in the regulation of neuronal survival. Indeed, SIRT1 has been reported to protect against neuronal death, while SIRT2 promotes neurodegeneration. The effect of SIRTs 3-7 on the regulation of neuronal survival, if any, has yet to be reported. METHODOLOGY AND PRINCIPAL FINDINGS: We examined the effect of expressing each of the seven SIRT proteins in healthy cerebellar granule neurons (CGNs or in neurons induced to die by low potassium (LK treatment. We report that SIRT1 protects neurons from LK-induced apoptosis, while SIRT2, SIRT3 and SIRT6 induce apoptosis in otherwise healthy neurons. SIRT5 is generally localized to both the nucleus and cytoplasm of CGNs and exerts a protective effect. In a subset of neurons, however, SIRT5 localizes to the mitochondria and in this case it promotes neuronal death. Interestingly, the protective effect of SIRT1 in neurons is not reduced by treatments with nicotinamide or sirtinol, two pharmacological inhibitors of SIRT1. Neuroprotection was also observed with two separate mutant forms of SIRT1, H363Y and H355A, both of which lack deacetylase activity. Furthermore, LK-induced neuronal death was not prevented by resveratrol, a pharmacological activator of SIRT1, at concentrations at which it activates SIRT1. We extended our analysis to HT-22 neuroblastoma cells which can be induced to die by homocysteic acid treatment. While the effects of most of the SIRT proteins were similar to that observed in CGNs, SIRT6 was modestly protective against homocysteic acid toxicity in HT-22 cells. SIRT5 was generally localized in the mitochondria of HT-22 cells and was apoptotic. CONCLUSIONS/SIGNIFICANCE: Overall, our study makes three contributions - (a it represents the first analysis of SIRT3-7 in the regulation of neuronal survival, (b it shows that neuroprotection by SIRT1 can be mediated by a novel, non

  17. Biological activity determination of I-BSP, a potent MMP 2 inhibitor, and its 123I tracer synthesis

    International Nuclear Information System (INIS)

    Oltenfreiter, R.; Staelens, L.; Slegers, G.; Lejeune, A.; Frankenne, F.; Dierckx, R.A.

    2002-01-01

    Aim: Matrix metalloproteinases (MMPs) are a family of at least 18 secreted and membrane-bound zinc endopeptidases. Collectively they function in the degradation of extracellular matrix proteins and play an important role in both normal and pathological tissue remodelling. Increased MMP activity is detected in a wide range of cancers and seems to be correlated to their invasive and metastatic potential. MMPs thus seem an attractive target for both diagnostic (SPECT tracer) and therapeutic purposes. Therefore, we synthesised a 123 I-labelled MMP 2 inhibitor and evaluated it in vitro. Materials and methods: The 123 I-labelled compound was synthesised by a Cu-assisted nucleophilic non-isotopic exchange starting from Br-BSP. After reaction, the mixture was purified by HPLC. IC 50 values were obtained by in vitro enzyme assays. A 1:1 mix between non-radiolabelled inhibitor (concentration range: 300 nM - 0.05 nM) and enzymes (MMP2, cMT1-MMP, cMT3-MMP) was incubated for 15 minutes at 37 0 C. The fluorescent substrate (Mca-Pro-Leu-Gly-Leu-Dap(Dnp)-Ala-Arg-NH2) was added and the increase of fluorescence versus time, due to the hydrolysis of substrate, was measured (GEMINI-XS, λ exc = 328 nm and λ em = 393nm). Initial velocities were calculated for different concentrations of inhibitor and the IC 50 values were then determined. Results: Radiochemical yield was 30% ±3%. Radiochemical purity was >95%. IC 50 values for inhibition of MMP2, cMT3-MMP and cMT1-MMP were 0.5 nM, 7.1 nM and 16.9 nM respectively. Conclusion: 123 I-BSP was synthesised with 30% ±3% yield. After HPLC the radiochemical purity was >95%. In vitro enzyme assays of I-BSP showed an inhibition of MMP2, cMT3-MMP and cMT1-MMP in the low nM range (0.5 nM, 7.1 nM and 16.9 nM respectively). In vivo studies (biodistribution, metabolizing) in mice will be performed in the near future

  18. Geometrically and conformationally restrained cinnamoyl compounds as inhibitors of HIV-1 integrase: synthesis, biological evaluation, and molecular modeling.

    Science.gov (United States)

    Artico, M; Di Santo, R; Costi, R; Novellino, E; Greco, G; Massa, S; Tramontano, E; Marongiu, M E; De Montis, A; La Colla, P

    1998-10-08

    Various cinnammoyl-based structures were synthesized and tested in enzyme assays as inhibitors of the HIV-1 integrase (IN). The majority of compounds were designed as geometrically or conformationally constrained analogues of caffeic acid phenethyl ester (CAPE) and were characterized by a syn disposition of the carbonyl group with respect to the vinylic double bond. Since the cinnamoyl moiety present in flavones such as quercetin (inactive on HIV-1-infected cells) is frozen in an anti arrangement, it was hoped that fixing our compounds in a syn disposition could favor anti-HIV-1 activity in cell-based assays. Geometrical and conformational properties of the designed compounds were taken into account through analysis of X-ray structures available from the Cambridge Structural Database. The polyhydroxylated analogues were prepared by reacting 3,4-bis(tetrahydropyran-2-yloxy)benzaldehyde with various compounds having active methylene groups such as 2-propanone, cyclopentanone, cyclohexanone, 1,3-diacetylbenzene, 2, 4-dihydroxyacetophenone, 2,3-dihydro-1-indanone, 2,3-dihydro-1, 3-indandione, and others. While active against both 3'-processing and strand-transfer reactions, the new compounds, curcumin included, failed to inhibit the HIV-1 multiplication in acutely infected MT-4 cells. Nevertheless, they specifically inhibited the enzymatic reactions associated with IN, being totally inactive against other viral (HIV-1 reverse transcriptase) and cellular (RNA polymerase II) nucleic acid-processing enzymes. On the other hand, title compounds were endowed with remarkable antiproliferative activity, whose potency correlated neither with the presence of catechols (possible source of reactive quinones) nor with inhibition of topoisomerases. The SARs developed for our compounds led to novel findings concerning the molecular determinants of IN inhibitory activity within the class of cinnamoyl-based structures. We hypothesize that these compounds bind to IN featuring the

  19. Synthesis of multivalent carbohydrate mimetics with aminopolyol end groups and their evaluation as L-selectin inhibitors

    Directory of Open Access Journals (Sweden)

    Joana Salta

    2015-05-01

    Full Text Available In this article a series of divalent and trivalent carbohydrate mimetics on the basis of an enantiopure aminopyran and of serinol is described. These aminopolyols are connected by amide bonds to carboxylic acid derived spacer units either by Schotten–Baumann acylation or by coupling employing HATU as reagent. The O-sulfation employing the SO3·DMF complex was optimized. It was crucial to follow this process by 700 MHz 1H NMR spectroscopy to ensure full conversion and to use a refined neutralization and purification protocol. Many of the compounds could not be tested as L-selectin inhibitor by SPR due to their insolubility in water, nevertheless, a divalent and a trivalent amide showed surprisingly good activities with IC50 values in the low micromolar range.

  20. Synthesis and Biological Evaluation of 3-Benzylidene-4-chromanone Derivatives as Free Radical Scavengers and α-Glucosidase Inhibitors.

    Science.gov (United States)

    Takao, Koichi; Yamashita, Marimo; Yashiro, Aruki; Sugita, Yoshiaki

    2016-01-01

    A series of 3-benzylidene-4-chromanone derivatives (3-20) were synthesized and the structure-activity relationships for antioxidant and α-glucosidase inhibitory activities were evaluated. Among synthesized compounds, compounds 5, 13, 18, which contain catechol moiety, showed the potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity (5: EC50 13 µM; 13: EC50 14 µM; 18: EC50 13 µM). The compounds 12, 14, 18 showed higher α-glucosidase inhibitory activity (12: IC50 15 µM; 14: IC50 25 µM; 18: IC50 28 µM). The compound 18 showed both of potent DPPH radical scavenging and α-glucosidase inhibitory activities. These data suggest that 3-benzylidene-4-chromanone derivatives, such as compound 18, may serve as the lead compound for the development of novel α-glucosidase inhibitors with antioxidant activity.

  1. The synthesis of isotopic fluorine and iodine-labeled COX-II inhibitor and in vitro validation

    Energy Technology Data Exchange (ETDEWEB)

    An, Gwang Gil; Lee, Tae Sub; Lee, Kyo Chul; Moon, Byung Seok; Choi, Chang Woon; Chun, Kwon Soo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2005-07-01

    In these day, NASIDs (non-steroidal antiinflammatory drugs) such as aspirin, diclofenac and ibuprofen are the most common medications used to reduce pain and inflammation. However, they act by inhibiting both COX-I and COX-II which can cause serious gastrointestinal side effects such as ulcers, stomach perforations and bleeds. COX-I produces prostaglandins believed to be responsible for the protection of the stomach lining. However, COX-II produces prostaglandins believed to be responsible for pain and inflammation. Recently, the most widely studied selective COX-II inhibitor such as celecoxib and rofecoxib' one work by inhibiting the effect of COX-II on pain and inflammation without inhibiting COX-I which protects gastrointestinal lining.

  2. Synthesis and biological evaluation of novel N-arylidenequinoline-3-carbohydrazides as potent β-glucuronidase inhibitors.

    Science.gov (United States)

    Taha, Muhammad; Sultan, Sadia; Nuzar, Herizal Ali; Rahim, Fazal; Imran, Syahrul; Ismail, Nor Hadiani; Naz, Humera; Ullah, Hayat

    2016-08-15

    Thirty N-arylidenequinoline-3-carbohydrazides (1-30) have been synthesized and evaluated against β-glucuronidase inhibitory potential. Twenty four analogs showed outstanding β-glucuronidase activity having IC50 values ranging between 2.11±0.05 and 46.14±0.95 than standard d-saccharic acid 1,4 lactone (IC50=48.4±1.25μM). Six analogs showed good β-glucuronidase activity having IC50 values ranging between 49.38±0.90 and 80.10±1.80. Structure activity relationship and the interaction of the active compounds and enzyme active site with the help of docking studies were established. Our study identifies novel series of potent β-glucuronidase inhibitors for further investigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Docking, synthesis and bioassay studies of imine derivatives as potential inhibitors for dengue NS2B/ NS3 serine protease

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    Neni Frimayanti

    2017-11-01

    Full Text Available Objective: To search imine derivatives as new active agents against dengue type 2 NS2B/NS3 using molecular docking, since there is no effective vaccine against flaviviral infections. Methods: In this research, molecular docking was performed for a series of imine derivatives and the information obtained from the docking studies was used to explore the binding modes of these imine derivatives with dengue type 2 NS2B/NS3 serine protease. A set of imine were synthesized and bioassay study of the inhibitory activities of these compounds was then performed. Results: The results indicated that MY8 and MY4 have the ability to inhibit DEN2 NS2B/NS3 proteolytic activity. Conclusions: These two compounds were chosen as the reference for the next stage in drug design as new inhibitor agents against NS2B/NS3.

  4. Synthesis and enzymatic evaluation of 2- and 4-aminothiazole-based inhibitors of neuronal nitric oxide synthase

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    Graham R. Lawton

    2009-06-01

    Full Text Available Highly potent and selective inhibitors of neuronal nitric oxide synthase (nNOS possessing a 2-aminopyridine group were recently designed and synthesized in our laboratory and were shown to have significant in vivo efficacy. In this work, analogs of our lead compound possessing 2- and 4-aminothiazole rings in place of the aminopyridine were synthesized. The less basic aminothiazole rings will be less protonated at physiological pH than the aminopyridine ring, and so the molecule will carry a lower net charge. This could lead to an increased ability to cross the blood-brain barrier thereby increasing the in vivo potency of these compounds. The 2-aminothiazole-based compound was less potent than the 2-aminopyridine-based analogue. 4-Aminothiazoles were unstable in water, undergoing tautomerization and hydrolysis to give inactive thiazolones.

  5. In vivo neuronal synthesis and axonal transport of Kunitz protease inhibitor (KPI)-containing forms of the amyloid precursor protein.

    Science.gov (United States)

    Moya, K L; Confaloni, A M; Allinquant, B

    1994-11-01

    We have shown previously that the amyloid precursor protein (APP) is synthesized in retinal ganglion cells and is rapidly transported down the axons, and that different molecular weight forms of the precursor have different developmental time courses. Some APP isoforms contain a Kunitz protease inhibitor (KPI) domain, and APP that lacks the KPI domain is considered the predominant isoform in neurons. We now show that, among the various rapidly transported APPs, a 140-kDa isoform contains the KPI domain. This APP isoform is highly expressed in rapidly growing retinal axons, and it is also prominent in adult axon endings. This 140-kDa KPI-containing APP is highly sulfated compared with other axonally transported isoforms. These results show that APP with the KPI domain is a prominent isoform synthesized in neurons in vivo, and they suggest that the regulation of protease activity may be an important factor during the establishment of neuronal connections.

  6. L-Cysteine/D,L-homocysteine-regulated ileum motility via system L and B°(,+) transporter: Modification by inhibitors of hydrogen sulfide synthesis and dietary treatments.

    Science.gov (United States)

    Yamane, Satoshi; Nomura, Ryouya; Yanagihara, Madoka; Nakamura, Hiroyuki; Fujino, Hiromichi; Matsumoto, Kenjiro; Horie, Syunji; Murayama, Toshihiko

    2015-10-05

    Previous studies including ours demonstrated that L-cysteine treatments decreased motility in gastrointestinal tissues including the ileum via hydrogen sulfide (H2S), which is formed from sulfur-containing amino acids such as L-cysteine and L-homocysteine. However, the amino acid transport systems involved in L-cysteine/L-homocysteine-induced responses have not yet been elucidated in detail; therefore, we investigated these systems pharmacologically by measuring electrical stimulation (ES)-induced contractions with amino acids in mouse ileum preparations. The treatments with L-cysteine and D,L-homocysteine inhibited ES-induced contractions in ileum preparations from fasted mice, and these responses were decreased by the treatment with 2-aminobicyclo[2.2.1]heptane-2-carboxylate (BCH), an inhibitor of systems L and B°(,+). The results obtained using ileum preparations and a model cell line (PC12 cells) with various amino acids and BCH showed that not only L-cysteine, but also aminooxyacetic acid and D,L-propargylglycine, which act as H2S synthesis inhibitors, appeared to be taken up by these preparations/cells in L and B°(,+) system-dependent manners. The L-cysteine and D,L-homocysteine responses were delayed and abolished, respectively, in ileum preparations from fed mice. Our results suggested that the regulation of ileum motility by L-cysteine and D,L-homocysteine was dependent on BCH-sensitive systems, and varied depending on feeding in mice. Therefore, the effects of aminooxyacetic acid and D,L-propargylglycine on transport systems need to be considered in pharmacological analyses. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Novel multi-target-directed ligands for Alzheimer's disease: Combining cholinesterase inhibitors and 5-HT6 receptor antagonists. Design, synthesis and biological evaluation.

    Science.gov (United States)

    Więckowska, Anna; Kołaczkowski, Marcin; Bucki, Adam; Godyń, Justyna; Marcinkowska, Monika; Więckowski, Krzysztof; Zaręba, Paula; Siwek, Agata; Kazek, Grzegorz; Głuch-Lutwin, Monika; Mierzejewski, Paweł; Bienkowski, Przemysław; Sienkiewicz-Jarosz, Halina; Knez, Damijan; Wichur, Tomasz; Gobec, Stanislav; Malawska, Barbara

    2016-11-29

    As currently postulated, a complex treatment may be key to an effective therapy for Alzheimer's disease (AD). Recent clinical trials in patients with moderate AD have shown a superior effect of the combination therapy of donepezil (a selective acetylcholinesterase inhibitor) with idalopirdine (a 5-HT 6 receptor antagonist) over monotherapy with donepezil. Here, we present the first report on the design, synthesis and biological evaluation of a novel class of multifunctional ligands that combines a 5-HT 6 receptor antagonist with a cholinesterase inhibitor. Novel multi-target-directed ligands (MTDLs) were designed by combining pharmacophores directed against the 5-HT 6 receptor (1-(phenylsulfonyl)-4-(piperazin-1-yl)-1H-indole) and cholinesterases (tacrine or N-benzylpiperidine analogues). In vitro evaluation led to the identification of tacrine derivative 12 with well-balanced potencies against the 5-HT 6 receptor (K b  = 27 nM), acetylcholinesterase and butyrylcholinesterase (IC 50 hAChE  = 12 nM, IC 50 hBuChE  = 29 nM). The compound also showed good in vitro blood-brain-barrier permeability (PAMPA-BBB assay), which was confirmed in vivo (open field study). Central cholinomimetic activity was confirmed in vivo in rats using a scopolamine-induced hyperlocomotion model. A novel class of multifunctional ligands with compound 12 as the best derivative in a series represents an excellent starting point for the further development of an effective treatment for AD. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. Synthesis and evaluation of the inhibitory activity of the four stereoisomers of the potent and selective human γ-glutamyl transpeptidase inhibitor GGsTop.

    Science.gov (United States)

    Watanabe, Bunta; Tabuchi, Yukiko; Wada, Kei; Hiratake, Jun

    2017-11-01

    2-Amino-4-{[3-(carboxymethyl)phenoxy](methoxy)phosphoryl}butanoic acid (GGsTop) is a potent, highly selective, nontoxic, and irreversible inhibitor of γ-glutamyl transpeptidase (GGT). GGsTop has been widely used in academic and medicinal research, and also as an active ingredient (Nahlsgen) in commercial anti-aging cosmetics. GGsTop consists of four stereoisomers due to the presence of two stereogenic centers, i.e., the α-carbon atom of the glutamate mimic (l/d) and the phosphorus atom (R P /S P ). In this study, each stereoisomer of GGsTop was synthesized stereoselectively and their inhibitory activity against human GGT was evaluated. The l- and d-configurations of each stereoisomer were determined by a combination of a chiral pool synthesis and chiral HPLC analysis. The synthesis of the four stereoisomers of GGsTop used chiral synthetic precursors that were separated by chiral HPLC on a preparative scale. With respect to the configuration of the α-carbon atom of the glutamate mimic, the l-isomer (k on =174M -1 s -1 ) was ca. 8-fold more potent than the d-isomer (k on =21.5M -1 s -1 ). In contrast, the configuration of the phosphorus atom is critical for GGT inhibitory activity. Based on a molecular modeling approach, the absolute configuration of the phosphorus atom of the active GGsTop isomers was postulated to be S P . The S P -isomers inhibited human GGT (k on =21.5-174M -1 s -1 ), while the R P -isomers were inactive even at concentrations of 0.1mM. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Function-Oriented Synthesis of Marine Phidianidine Derivatives as Potential PTP1B Inhibitors with Specific Selectivity

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    Jin Liu

    2018-03-01

    Full Text Available Phidianidines A and B are two novel marine indole alkaloids bearing an uncommon 1,2,4-oxadiazole ring and exhibiting various biological activities. Our previous research showed that the synthesized phidianidine analogs had the potential to inhibit the activity of protein tyrosine phosphatase 1B (PTP1B, a validated target for Type II diabetes, which indicates that these analogs are worth further structural modification. Therefore, in this paper, a series of phidianidine derivatives were designed and rapidly synthesized with a function-oriented synthesis (FOS strategy. Their inhibitory effects on PTP1B and T-cell protein tyrosine phosphatase (TCPTP were evaluated, and several compounds displayed significant inhibitory potency and specific selectivity over PTP1B. The structure–activity relationship (SAR and molecular docking analyses are also described.

  10. Function-Oriented Synthesis of Marine Phidianidine Derivatives as Potential PTP1B Inhibitors with Specific Selectivity.

    Science.gov (United States)

    Liu, Jin; Chen, Yu; Li, Jing-Ya; Luo, Cheng; Li, Jia; Chen, Kai-Xian; Li, Xu-Wen; Guo, Yue-Wei

    2018-03-20

    Phidianidines A and B are two novel marine indole alkaloids bearing an uncommon 1,2,4-oxadiazole ring and exhibiting various biological activities. Our previous research showed that the synthesized phidianidine analogs had the potential to inhibit the activity of protein tyrosine phosphatase 1B (PTP1B), a validated target for Type II diabetes, which indicates that these analogs are worth further structural modification. Therefore, in this paper, a series of phidianidine derivatives were designed and rapidly synthesized with a function-oriented synthesis (FOS) strategy. Their inhibitory effects on PTP1B and T-cell protein tyrosine phosphatase (TCPTP) were evaluated, and several compounds displayed significant inhibitory potency and specific selectivity over PTP1B. The structure-activity relationship (SAR) and molecular docking analyses are also described.

  11. Transcriptome analysis of the Spodoptera frugiperda ascovirus in vivo provides insights into how its apoptosis inhibitors and caspase promote increased synthesis of viral vesicles and virion progeny.

    Science.gov (United States)

    Zaghloul, Heba; Hice, Robert; Arensburger, Peter; Federici, Brian A

    2017-09-27

    that continue to produce virions. Our transcriptome analysis of genome expression in vivo by the Spodoptera frugiperda ascovirus shows that inhibitors of apoptosis are expressed first enabling viral replication to proceed, after which the SfAV-1a caspase is synthesized, leading to viral vesicle synthesis and subsequent extensive production of progeny virions. Moreover, we detected numerous bicistronic and tricistronic mRNA messages in the ascovirus transcriptome, implying ascoviruses use other non-canonical translational mechanisms such as Internal Ribosome Entry Site (IRES). These results provide the first insights into the molecular biology of a unique coordinated gene expression pattern in which cell architecture is markedly modified, more than in any other known eukaryotic virus, to promote viral reproduction and transmission. Copyright © 2017 American Society for Microbiology.

  12. Prolactin protects retinal pigment epithelium by inhibiting sirtuin 2-dependent cell death

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    Rodrigo Meléndez García

    2016-05-01

    Full Text Available The identification of pathways necessary for retinal pigment epithelium (RPE function is fundamental to uncover therapies for blindness. Prolactin (PRL receptors are expressed in the retina, but nothing is known about the role of PRL in RPE. Using the adult RPE 19 (ARPE-19 human cell line and mouse RPE, we identified the presence of PRL receptors and demonstrated that PRL is necessary for RPE cell survival via anti-apoptotic and antioxidant actions. PRL promotes the antioxidant capacity of ARPE-19 cells by reducing glutathione. It also blocks the hydrogen peroxide-induced increase in deacetylase sirtuin 2 (SIRT2 expression, which inhibits the TRPM2-mediated intracellular Ca2+ rise associated with reduced survival under oxidant conditions. RPE from PRL receptor-null (prlr−/− mice showed increased levels of oxidative stress, Sirt2 expression and apoptosis, effects that were exacerbated in animals with advancing age. These observations identify PRL as a regulator of RPE homeostasis.

  13. Gut microbiota and sirtuins in obesity-related inflammation and bowel dysfunction

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    Lakhan Shaheen E

    2011-11-01

    Full Text Available Abstract Obesity is a chronic disease characterized by persistent low-grade inflammation with alterations in gut motility. Motor abnormalities suggest that obesity has effects on the enteric nervous system (ENS, which controls virtually all gut functions. Recent studies have revealed that the gut microbiota can affect obesity and increase inflammatory tone by modulating mucosal barrier function. Furthermore, the observation that inflammatory conditions influence the excitability of enteric neurons may add to the gut dysfunction in obesity. In this article, we discuss recent advances in understanding the role of gut microbiota and inflammation in the pathogenesis of obesity and obesity-related gastrointestinal dysfunction. The potential contribution of sirtuins in protecting or regulating the circuitry of the ENS under inflamed states is also considered.

  14. Molecular evolutionary patterns of NAD+/Sirtuin aging signaling pathway across taxa.

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    Uma Gaur

    Full Text Available A deeper understanding of the conserved molecular mechanisms in different taxa have been made possible only because of the evolutionary conservation of crucial signaling pathways. In the present study, we explored the molecular evolutionary pattern of selection signatures in 51 species for 10 genes which are important components of NAD+/Sirtuin pathway and have already been directly linked to lifespan extension in worms and mice. Selection pressure analysis using PAML program revealed that MRPS5 and PPARGC1A were under significant constraints because of their functional significance. FOXO3a also displayed strong purifying selection. All three sirtuins, which were SIRT1, SIRT2 and SIRT6, displayed a great degree of conservation between taxa, which is consistent with the previous report. A significant evolutionary constraint is seen on the anti-oxidant gene, SOD3. As expected, TP53 gene was under significant selection pressure in mammals, owing to its major role in tumor progression. Poly-ADP-ribose polymerase (PARP genes displayed the most sites under positive selection. Further 3D structural analysis of PARP1 and PARP2 protein revealed that some of these positively selected sites caused a change in the electrostatic potential of the protein structure, which may allow a change in its interaction with other proteins and molecules ultimately leading to difference in the function. Although the functional significance of the positively selected sites could not be established in the variants databases, yet it will be interesting to see if these sites actually affect the function of PARP1 and PARP2.

  15. Calorie restriction extends the chronological lifespan of Saccharomyces cerevisiae independently of the Sirtuins.

    Science.gov (United States)

    Smith, Daniel L; McClure, Julie M; Matecic, Mirela; Smith, Jeffrey S

    2007-10-01

    Calorie restriction (CR) extends the mean and maximum lifespan of a wide variety of organisms ranging from yeast to mammals, although the molecular mechanisms of action remain unclear. For the budding yeast Saccharomyces cerevisiae reducing glucose in the growth medium extends both the replicative and chronological lifespans (CLS). The conserved NAD(+)-dependent histone deacetylase, Sir2p, promotes replicative longevity in S. cerevisiae by suppressing recombination within the ribosomal DNA locus and has been proposed to mediate the effects of CR on aging. In this study, we investigated the functional relationships of the yeast Sirtuins (Sir2p, Hst1p, Hst2p, Hst3p and Hst4p) with CLS and CR. SIR2, HST2, and HST4 were not major regulators of CLS and were not required for the lifespan extension caused by shifting the glucose concentration from 2 to 0.5% (CR). Deleting HST1 or HST3 moderately shortened CLS, but did not prevent CR from extending lifespan. CR therefore works through a Sirtuin-independent mechanism in the chronological aging system. We also show that low temperature or high osmolarity additively extends CLS when combined with CR, suggesting that these stresses and CR act through separate pathways. The CR effect on CLS was not specific to glucose. Restricting other simple sugars such as galactose or fructose also extended lifespan. Importantly, growth on nonfermentable carbon sources that force yeast to exclusively utilize respiration extended lifespan at nonrestricted concentrations and provided no additional benefit when restricted, suggesting that elevated respiration capacity is an important determinant of chronological longevity.

  16. High frequencies of chromatid aberrations produced during G/sub 2/ in human lymphocytes by very low doses (0. 025-0. 4 Gy) of X-rays in combination with inhibitors of DNA synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, H.C.; Kihlman, B.A. (Uppsala Univ. (Sweden). Dept. of Genetics)

    1984-09-01

    Whole-blood cultures of human lymphocytes were exposed in the G/sub 2/-phase (3.5 h before harvesting) to various doses of X-rays and post-treated for 3 h with inhibitors of DNA synthesis. The inhibitors used were 2'-deoxyadenosine (dAdo), hydroxyurea (HU) and 1-..beta..-D-arabinofuranosylcytosine (ara-C). To prevent deamination of dAdo by adenosine deaminase (ADA), the dAdo treatments were carried out in the presence of the ADA inhibitor coformycin. HU and ara-C were used either alone or in combination. After the 3-h inhibitor treatments, the cultures were harvested and slides prepared and analyzed for chromatid aberrations in metaphase. When the inhibitors were used at concentrations high enough to cause marked chromosome damage by themselves, very low doses of X-rays (0.025-0.2 Gy) were sufficient to produce a dramatic increase in the frequency of chromatid aberrations. High frequencies of chromatid aberrations were also obtained when cultures that had received moderate doses of X-rays (0.4-0.8 Gy) were post-treated with low inhibitor concentrations that produce no or only a few aberrations by themselves.

  17. Development of novel (1-H benzimidazole bearing pyrimidine-trione based MAO-A inhibitors: Synthesis, docking studies and antidepressant activity

    Directory of Open Access Journals (Sweden)

    Bijo Mathew

    2016-09-01

    Full Text Available The synthesis of some novel (1-H benzimidazole bearing pyrimidine-trione based MAO-A inhibitors were achieved by the reaction between 2E-1-(1H-benzimidazol-2-yl-3-phenylprop-2-en-1-ones(4a–f and barbituric acid in the presence of a catalytic amount of acetic acid medium. All the final structures were assigned on the basis of IR, 1HNMR and mass spectra analyses. All the synthesized derivatives showed good antidepressant activity when compared to the standard clomipiramine at a dose level of 20 mg/kg. The compound (5d 5-{(2E-1-(1H-benzimidazol-2-yl-3-[4-(dimethylaminophenyl] prop-2-en-1-ylidene} pyrimidine-2, 4, 6(1H,3H,5H-trione significantly reduced the duration of immobility times at 50 mg/kg−1 dose level when compared to the standard drug. Molecular docking studies revealed the need for an extra hydrophobic interaction in the titled scaffold for acquiring the promising experimental values. It has been concluded that the computational values obtained after the docking calculation are in good agreement with the experimental values.

  18. Design, synthesis and biological evaluations of N-Hydroxy thienopyrimidine-2,4-diones as inhibitors of HIV reverse transcriptase-associated RNase H.

    Science.gov (United States)

    Kankanala, Jayakanth; Kirby, Karen A; Huber, Andrew D; Casey, Mary C; Wilson, Daniel J; Sarafianos, Stefan G; Wang, Zhengqiang

    2017-12-01

    Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) is the only HIV enzymatic function not targeted by current antiviral drugs. Although various chemotypes have been reported to inhibit HIV RNase H, few have shown significant antiviral activities. We report herein the design, synthesis and biological evaluation of a novel N-hydroxy thienopyrimidine-2,3-dione chemotype (11) which potently and selectively inhibited RNase H with considerable potency against HIV-1 in cell culture. Current structure-activity-relationship (SAR) identified analogue 11d as a nanomolar inhibitor of RNase H (IC 50  = 0.04 μM) with decent antiviral potency (EC 50  = 7.4 μM) and no cytotoxicity (CC 50  > 100 μM). In extended biochemical assays compound 11d did not inhibit RT polymerase (pol) while inhibiting integrase strand transfer (INST) with 53 fold lower potency (IC 50  = 2.1 μM) than RNase H inhibition. Crystallographic and molecular modeling studies confirmed the RNase H active site binding mode. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Studies on Synthesis and Structure-Activity Relationship (SAR of Derivatives of a New Natural Product from Marine Fungi as Inhibitors of Influenza Virus Neuraminidase

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    Yongcheng Lin

    2011-10-01

    Full Text Available Based on the natural isoprenyl phenyl ether from a mangrove-derived fungus, 32 analogues were synthesized and evaluated for inhibitory activity against influenza H1N1 neuraminidase. Compound 15 (3-(allyloxy-4-hydroxybenzaldehyde exhibited the most potent inhibitory activity, with IC50 values of 26.96 μM for A/GuangdongSB/01/2009 (H1N1, 27.73 μM for A/Guangdong/03/2009 (H1N1, and 25.13 μM for A/Guangdong/05/2009 (H1N1, respectively, which is stronger than the benzoic acid derivatives (~mM level. These are a new kind of non-nitrogenous aromatic ether Neuraminidase (NA inhibitors. Their structures are simple and the synthesis routes are not complex. The structure-activity relationship (SAR analysis revealed that the aryl aldehyde and unsubstituted hydroxyl were important to NA inhibitory activities. Molecular docking studies were carried out to explain the SAR of the compounds, and provided valuable information for further structure modification.

  20. Synthesis, biological evaluation and docking studies of 2,3-dihydroquinazolin-4(1H)-one derivatives as inhibitors of cholinesterases.

    Science.gov (United States)

    Sarfraz, Muhammad; Sultana, Nargis; Rashid, Umer; Akram, Muhammad Safwan; Sadiq, Abdul; Tariq, Muhammad Ilyas

    2017-02-01

    In search of potent inhibitors of cholinesterases, we have synthesized and evaluate a number of 2,3-dihydroquinazolin-4(1H)-one derivatives. The synthetic approach provided an efficient synthesis of the target molecules with excellent yield. All the tested compounds showed activity against both the enzymes in micromolar range. In many case, the inhibition of both enzymes are higher than or comparable to the standard drug galatamine. With the selectivity index of 2.3 for AChE, compound 5f can be considered as a potential lead compound with a feature of dual AChE/BChE inhibition with IC 50 =1.6±0.10μM (AChE) and 3.7±0.18μM (BChE). Binding modes of the synthesized compounds were explored by using GOLD (Genetic Optimization for Ligand Docking) suit v5.4.1. The computed binding modes of these compounds in the active site of AChE and BChE provide an insight into the mechanism of inhibition of these two enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Synthesis of /sup 14/C- and /sup 3/H-labeled fluoxetine, a selective serotonin uptake inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, D.W.; Krushinski, J.H.; Wong, D.T.; Kau, D.

    1987-11-01

    Fluoxetine (N-methyl-..gamma..-(4-(trifluoromethyl)phenoxy) benzenepropanamine) is a potent, highly selective serotonin uptake inhibitor that is useful in treating a variety of major psychiatric derangements. We have synthesized this compound in /sup 14/C- and /sup 3/H-labeled forms. The tritium label was introduced in the final step by catalytic dehalogenation of the brominated fluoxetine precursor. Reaction conditions could be controlled such that catalytic hydrogenolysis of the labile C-O benzylic bond was minimized. Following HPLC purification, (/sup 3/H)-fluoxetine was obtained in a state of high radiochemical purity (98%) and specific activity (20.4 Ci/mmol). The /sup 14/C-label was introduced in the final step via a nucleophilic aromatic substitution reaction between the sodium salt of ..cap alpha..-(2-(methylamino)ethyl)benzenemethanol and uniformly ring-labeled p-chlorobenzotrifluoride. Following purification by flash chromatography, (/sup 14/C)-fluoxetine was obtained in 98.3% radiochemical purity with a specific activity of 5.52 mCi/mmol.

  2. Effects of some inhibitors of protein synthesis on the chloroplast fine structure, CO2 fixation and the Hill reaction activity

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    S. Więckowski

    2015-01-01

    Full Text Available A comparative study concerning the effects of chloramphenicol (100 μg ml-1, actidione (10 μg ml-1, 5-bromouracil (190 μg ml-1, actinomycin D (30 μg ml-1 and DL-ethionine (800 μg ml-1 on the chloroplast fine structure, 14CO2 incorporation and the Hill reaction activity was the subject of the experiments presented in this paper. The experiments were conducted on bean seedlings under the conditions when chlorophyll accumulation was inhibited only partially. The results obtained indicate that chloromphenicol is responsible for the reduction of the number of grana per section of plastid and for the formation of numerous vesicles in the stroma. In the presence of actidione, actinomycin D or DL-ethionine the lamellae are poorly differentiated into .stroma and granum regions and there occur disturbances in the typical orientation of lamellae within chloroplasts. Only in the presence of 5-bromouracil the development of chloroplast structure resemble that in control plants. A comparison of the results obtained with those published earlier (Więckowski et al., 1974; Ficek and Więckowski, 1974 shows that such processes as assimilatory pigment accumulation, the rate of CO2 fixation, the Hill reaction activity, and the development of lamellar system are suppressed in a different extent by the inhibitors used.

  3. Design, synthesis and identification of silicon-containing HCV NS5A inhibitors with pan-genotype activity.

    Science.gov (United States)

    Liu, Baomin; Gai, Kuo; Qin, Hui; Liu, Xushi; Cao, Yuan; Lu, Qin; Lu, Dandan; Chen, Deyang; Shen, Hengqiao; Song, Wei; Zhang, Yang; Wang, Xiaojin; Xu, Hongjiang; Zhang, Yinsheng

    2018-03-25

    Modification of a HCV NS5A inhibitor, ombitasvir, led to the identification of 10d with improved pan-genotype NS5A inhibition and better pharmacokinetic properties. The key structural changes to ombitasvir include bioisosteric replacement of carbon with silicon atom. Compared with ombitasvir, the activity of anti-HCV genotypes (GT 1 to 6) of 10d is increased to some extent, especially the inhibitory activity against genotype 3a and 6a is increased by more than seven times, and the dog's in vivo pharmacokinetics properties were also superior to ombitasvir. Further drug evaluation showed that 10d was similar to ombitasvir on plasma protein binding and liver distribution profiles, with no cytotoxicity and no inhibitory effect on both CYP 450 and hERG ligand binding. However, permeability assay results indicated that 10d was not the substrate of P-gp or BCRP transporter, which is different from that of ombitasvir. The results of a 14-day repeat-dose toxicity study identified no toxicity with 10d. Our findings in preclinical tests suggest that the silicon-containing compound 10d could be worthy of continued study as a potential drug candidate. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  4. Synthesis of bis-indolylmethanes as new potential inhibitors of β-glucuronidase and their molecular docking studies.

    Science.gov (United States)

    Taha, Muhammad; Ullah, Hayat; Al Muqarrabun, Laode Muhammad Ramadhan; Khan, Muhammad Naseem; Rahim, Fazal; Ahmat, Norizan; Ali, Muhammad; Perveen, Shahnaz

    2018-01-01

    Thirty-two (32) bis-indolylmethane-hydrazone hybrids 1-32 were synthesized and characterized by 1 HNMR, 13 CNNMR and HREI-MS. All compounds were evaluated in vitro for β-glucuronidase inhibitory potential. All analogs showed varying degree of β-glucuronidase inhibitory potential ranging from 0.10 ± 0.01 to 48.50 ± 1.10 μM when compared with the standard drug d-saccharic acid-1,4-lactone (IC 50 value 48.30 ± 1.20 μM). Derivatives 1-32 showed the highest β-glucuronidase inhibitory potentials which is many folds better than the standard drug d-saccharic acid-1,4-lactone. Further molecular docking study validated the experimental results. It was proposed that bis-indolylmethane may interact with some amino acid residues located within the active site of β-glucuronidase enzyme. This study has culminated in the identification of a new class of potent β-glucuronidase inhibitors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Synthesis and biological evaluation of 5-carbamoyl-2-phenylpyrimidine derivatives as novel and potent PDE4 inhibitors.

    Science.gov (United States)

    Goto, Taiji; Shiina, Akiko; Yoshino, Toshiharu; Mizukami, Kiyoshi; Hirahara, Kazuki; Suzuki, Osamu; Sogawa, Yoshitaka; Takahashi, Tomoko; Mikkaichi, Tsuyoshi; Nakao, Naoki; Takahashi, Mizuki; Hasegawa, Masashi; Sasaki, Shigeki

    2013-11-15

    5-Carbamoyl-2-phenylpyrimidine derivative 2 has been identified as a phosphodiesterase 4 (PDE4) inhibitor with moderate PDE4B inhibitory activity (IC50=200 nM). Modification of the carboxylic acid moiety of 2 gave N-neopentylacetamide derivative 10f, which had high in vitro PDE4B inhibitory activity (IC50=8.3 nM) and in vivo efficacy against lipopolysaccharide (LPS)-induced pulmonary neutrophilia in mice (ID50=16 mg/kg, ip). Furthermore, based on the X-ray crystallography of 10f bound to the human PDE4B catalytic domain, we designed 7,8-dihydro-6H-pyrido[4,3-d]pyrimidin-5-one derivative 39 which has a fused bicyclic lactam scaffold. Compound 39 exhibited excellent inhibitory activity against LPS-induced tumor necrosis factor alpha (TNF-α) production in mouse splenocytes (IC50=0.21 nM) and in vivo anti-inflammatory activity against LPS-induced pulmonary neutrophilia in mice (41% inhibition at a dose of 1.0 mg/kg, i.t.). Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Synthesis of substituted 2-(β-D-glucopyranosyl)-benzimidazoles and their evaluation as inhibitors of glycogen phosphorylase.

    Science.gov (United States)

    Bokor, Éva; Szilágyi, Enikő; Docsa, Tibor; Gergely, Pál; Somsák, László

    2013-11-15

    Microwave assisted condensation of O-perbenzoylated C-(β-d-glucopyranosyl)formic acid with 1,2-diaminobenzenes in the presence of triphenylphosphite gave the corresponding O-protected 2-(β-d-glucopyranosyl)-benzimidazoles in moderate yields. O-Perbenzoylated C-(β-d-glucopyranosyl)formamide and -thioformamide were transformed into the corresponding ethyl C-(β-d-glucopyranosyl)formimidate and -thioformimidate, respectively, by Et3O·BF4. Treatment of the formimidate with 1,2-diaminobenzenes afforded O-protected 2-(β-d-glucopyranosyl)-benzimidazoles in good to excellent yields. Similar reaction of the thioformimidate gave these compounds in lower yields. The O-benzoyl protecting groups were removed by the Zemplén protocol. These test compounds were assayed against rabbit muscle glycogen phosphorylase (GP) b, the prototype of liver GP, the rate limiting enzyme of glycogen degradation. The best inhibitors were 2-(β-d-glucopyranosyl)-4-methyl-benzimidazole (Ki=2.8μM) and 2-(β-d-glucopyranosyl)-naphtho[2,3-d]imidazole (Ki=2.1μM) exhibiting a ∼3-4 times stronger binding than the unsubstituted parent compound. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Design, Synthesis, and Biological Evaluation of Small, High-Affinity Siglec-7 Ligands: Toward Novel Inhibitors of Cancer Immune Evasion.

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    Prescher, Horst; Frank, Martin; Gütgemann, Stephan; Kuhfeldt, Elena; Schweizer, Astrid; Nitschke, Lars; Watzl, Carsten; Brossmer, Reinhard

    2017-02-09

    Natural killer cells are able to directly lyse tumor cells, thereby participating in the immune surveillance against cancer. Unfortunately, many cancer cells use immune evasion strategies to avoid their eradication by the immune system. A prominent escape strategy of malignant cells is to camouflage themselves with Siglec-7 ligands, thereby recruiting the inhibitory receptor Siglec-7 expressed on the NK cell surface which subsequently inhibits NK-cell-mediated lysis. Here we describe the synthesis and evaluation of the first, high-affinity low molecular weight Siglec-7 ligands to interfere with cancer cell immune evasion. The compounds are Sialic acid derivatives and bind with low micromolar K d values to Siglec-7. They display up to a 5000-fold enhanced affinity over the unmodified sialic acid scaffold αMe Neu5Ac, the smallest known natural Siglec-7 ligand. Our results provide a novel immuno-oncology strategy employing natural immunity in the fight against cancers, in particular blocking Siglec-7 with low molecular weight compounds.

  8. Effect of DNA polymerase inhibitors on DNA repair in intact and permeable human fibroblasts: Evidence that DNA polymerases δ and β are involved in DNA repair synthesis induced by N-methyl-N'-nitro-N-nitrosoguanidine

    International Nuclear Information System (INIS)

    Hammond, R.A.; Miller, M.R.; McClung, J.K.

    1990-01-01

    The involvement of DNA polymerases α, β, and δ in DNA repair synthesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was investigated in human fibroblasts (HF). The effects of anti-(DNA polymerase α) monoclonal antibody, (p-n-butylphenyl)deoxyguanosine triphosphate (BuPdGTP), dideoxythymidine triphosphate (ddTTP), and aphidicolin on MNNG-induced DNA repair synthesis were investigated to dissect the roles of the different DNA polymerases. A subcellular system (permeable cells), in which DNA repair synthesis and DNA replication were differentiated by CsCl gradient centrifugation of BrdUMP density-labeled DNA, was used to examine the effects of the polymerase inhibitors. Another approach investigated the effects of several of these inhibitors of MNNG-induced DNA repair synthesis in intact cells by measuring the amount of [ 3 H]thymidine incorporated into repair DNA as determined by autoradiography and quantitation with an automated video image analysis system. In permeable cells, MNNG-induced DNA repair synthesis was inhibited 56% by 50 μg of aphidicolin/mL, 6% by 10 μM BuPdGTP, 13% by anti-(DNA polymerse α) monoclonal antibodies, and 29% by ddTTP. In intact cells, MNNG-induced DNA repair synthesis was inhibited 57% by 50 μg of aphidicolin/mL and was not significantly inhibited by microinjecting anti-(DNA polymerase α) antibodies into HF nuclei. These results indicate that both DNA polymerase δ and β are involved in repairing DNA damage caused by MNNG

  9. Design, synthesis and molecular modeling of new 4-phenylcoumarin derivatives as tubulin polymerization inhibitors targeting MCF-7 breast cancer cells.

    Science.gov (United States)

    Batran, Rasha Z; Kassem, Asmaa F; Abbas, Eman M H; Elseginy, Samia A; Mounier, Marwa M

    2018-07-23

    A new set of 4-phenylcoumarin derivatives was designed and synthesized aiming to introduce new tubulin polymerization inhibitors as anti-breast cancer candidates. All the target compounds were evaluated for their cytotoxic effects against MCF-7 cell line, where compounds 2f, 3a, 3b, 3f, 7a and 7b, showed higher cytotoxic effect (IC 50  = 4.3-21.2 μg/mL) than the reference drug doxorubicin (IC 50  = 26.1 μg/mL), additionally, compounds 1 and 6b exhibited the same potency as doxorubicin (IC 50  = 25.2 and 28.0 μg/mL, respectively). The thiazolidinone derivatives 3a, 3b and 3f with potent and selective anticancer effects towards MCF-7 cells (IC 50  = 11.1, 16.7 and 21.2 μg/mL) were further assessed for tubulin polymerization inhibition effects which showed that the three compounds were potent tubulin polymerization suppressors with IC 50 values of 9.37, 2.89 and 6.13 μM, respectively, compared to the reference drug colchicine (IC 50  = 6.93 μM). The mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cells were determined for compound 3a due to its potent and selective cytotoxic effects in addition to its promising tubulin polymerization inhibition potency. The results revealed that compound 3a induced cell cycle cessation at G2/M phase and accumulation of cells in pre-G1 phase and prevented its mitotic cycle, in addition to its activation of caspase-7 mediating apoptosis of MCF-7 cells. Molecular modeling studies for compounds 3a, 3b and 3f were carried out on tubulin crystallography, the results indicated that the compounds showed binding mode similar to the co-crystalized ligand; colchicine. Moreover, pharmacophore constructed models and docking studies revealed that thiazolidinone, acetamide and coumarin moieties are crucial for the activity. Molecular dynamics (MD) studies were carried out for the three compounds over 100 ps. MD results of compound 3a showed that it reached the stable state

  10. MSN2 and MSN4 link calorie restriction and TOR to sirtuin-mediated lifespan extension in Saccharomyces cerevisiae.

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    Oliver Medvedik

    2007-10-01

    Full Text Available Calorie restriction (CR robustly extends the lifespan of numerous species. In the yeast Saccharomyces cerevisiae, CR has been proposed to extend lifespan by boosting the activity of sirtuin deacetylases, thereby suppressing the formation of toxic repetitive ribosomal DNA (rDNA circles. An alternative theory is that CR works by suppressing the TOR (target of rapamycin signaling pathway, which extends lifespan via mechanisms that are unknown but thought to be independent of sirtuins. Here we show that TOR inhibition extends lifespan by the same mechanism as CR: by increasing Sir2p activity and stabilizing the rDNA locus. Further, we show that rDNA stabilization and lifespan extension by both CR and TOR signaling is due to the relocalization of the transcription factors Msn2p and Msn4p from the cytoplasm to the nucleus, where they increase expression of the nicotinamidase gene PNC1. These findings suggest that TOR and sirtuins may be part of the same longevity pathway in higher organisms, and that they may promote genomic stability during aging.

  11. The NAD-Dependent Deacetylase Sirtuin-1 Regulates the Expression of Osteogenic Transcriptional Activator Runt-Related Transcription Factor 2 (Runx2 and Production of Matrix Metalloproteinase (MMP-13 in Chondrocytes in Osteoarthritis

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    Koh Terauchi

    2016-06-01

    Full Text Available Aging is one of the major pathologic factors associated with osteoarthritis (OA. Recently, numerous reports have demonstrated the impact of sirtuin-1 (Sirt1, which is the NAD-dependent deacetylase, on human aging. It has been demonstrated that Sirt1 induces osteogenic and chondrogenic differentiation of mesenchymal stem cells. However, the role of Sirt1 in the OA chondrocytes still remains unknown. We postulated that Sirt1 regulates a hypertrophic chondrocyte lineage and degeneration of articular cartilage through the activation of osteogenic transcriptional activator Runx2 and matrix metalloproteinase (MMP-13 in OA chondrocytes. To verify whether sirtuin-1 (Sirt1 regulates chondrocyte activity in OA, we studied expressions of Sirt1, Runx2 and production of MMP-13, and their associations in human OA chondrocytes. The expression of Sirt1 was ubiquitously observed in osteoarthritic chondrocytes; in contrast, Runx2 expressed in the osteophyte region in patients with OA and OA model mice. OA relating catabolic factor IL-1βincreased the expression of Runx2 in OA chondrocytes. OA chondrocytes, which were pretreated with Sirt1 inhibitor, inhibited the IL-1β-induced expression of Runx2 compared to the control. Since the Runx2 is a promotor of MMP-13 expression, Sirt1 inactivation may inhibit the Runx2 expression and the resultant down-regulation of MMP-13 production in chondrocytes. Our findings suggest thatSirt1 may regulate the expression of Runx2, which is the osteogenic transcription factor, and the production of MMP-13 from chondrocytes in OA. Since Sirt1 activity is known to be affected by several stresses, including inflammation and oxidative stress, as well as aging, SIRT may be involved in the development of OA.

  12. Evidence synthesis and decision modelling to support complex decisions: stockpiling neuraminidase inhibitors for pandemic influenza usage [version 2; referees: 2 approved

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    Samuel I. Watson

    2017-03-01

    Full Text Available Objectives: The stockpiling of neuraminidase inhibitor (NAI antivirals as a defence against pandemic influenza is a significant public health policy decision that must be made despite a lack of conclusive evidence from randomised controlled trials regarding the effectiveness of NAIs on important clinical end points such as mortality. The objective of this study was to determine whether NAIs should be stockpiled for treatment of pandemic influenza on the basis of current evidence. Methods: A decision model for stockpiling was designed. Data on previous pandemic influenza epidemiology was combined with data on the effectiveness of NAIs in reducing mortality obtained from a recent individual participant meta-analysis using observational data. Evidence synthesis techniques and a bias modelling method for observational data were used to incorporate the evidence into the model. The stockpiling decision was modelled for adults (≥16 years old and the United Kingdom was used as an example. The main outcome was the expected net benefits of stockpiling in monetary terms. Health benefits were estimated from deaths averted through stockpiling. Results: After adjusting for biases in the estimated effectiveness of NAIs, the expected net benefit of stockpiling in the baseline analysis was £444 million, assuming a willingness to pay of £20,000/QALY ($31,000/QALY. The decision would therefore be to stockpile NAIs. There was a greater probability that the stockpile would not be utilised than utilised. However, the rare but catastrophic losses from a severe pandemic justified the decision to stockpile. Conclusions: Taking into account the available epidemiological data and evidence of effectiveness of NAIs in reducing mortality, including potential biases, a decision maker should stockpile anti-influenza medication in keeping with the postulated decision rule.

  13. In-silico docking based design and synthesis of [1H,3H] imidazo[4,5-b] pyridines as lumazine synthase inhibitors for their effective antimicrobial activity.

    Science.gov (United States)

    Harer, Sunil L; Bhatia, Manish S

    2014-10-01

    The imidazopyridine moiety is important pharmacophore that has proven to be useful for a number of biologically relevant targets, also reported to display antibacterial, antifungal, antiviral properties. Riboflavin biosynthesis involving catalytic step of Lumazine synthase is absent in animals and human, but present in microorganism, one of marked advantage of this study. Still, this path is not exploited as antiinfective target. Here, we proposed different interactions between [1H,3H] imidazo[4,5-b] pyridine test ligands and target protein Lumazine synthase (protein Data Bank 2C92), one-step synthesis of title compounds and further evaluation of them for in vitro antimicrobial activity. Active pocket of the target protein involved in the interaction with the test ligands molecules was found using Biopredicta tools in VLifeMDS 4.3 Suite. In-silico docking suggests H-bonding, hydrophobic interaction, charge interaction, aromatic interaction, and Vanderwaal forces responsible for stabilizing enzyme-inhibitor complex. Disc diffusion assay method was used for in vitro antimicrobial screening. Investigation of possible interaction between test ligands and target lumazine synthase of Mycobacterium tuberculosis suggested 1i and 2f as best fit candidates showing hydrogen bonding, hydrophobic, aromatic and Vanderwaal's forces. Among all derivatives 1g, 1j, 1k, 1l, 2a, 2c, 2d, 2e, 2h, and 2j exhibited potent activities against bacteria and fungi compared to the standard Ciprofloxacin and Fluconazole, respectively. The superiority of 1H imidazo [4,5-b] pyridine compounds having R' = Cl >No2 > NH2 at the phenyl/aliphatic moiety resident on the imidazopyridine, whereas leading 3H imidazo[4,5-b] pyridine compounds containing R/Ar = Cl > No2 > NH2> OCH3 substituents on the 2(nd) position of imidazole.

  14. In-silico docking based design and synthesis of [1H,3H] imidazo[4,5-b] pyridines as lumazine synthase inhibitors for their effective antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Sunil L Harer

    2014-01-01

    Full Text Available Purpose: The imidazopyridine moiety is important pharmacophore that has proven to be useful for a number of biologically relevant targets, also reported to display antibacterial, antifungal, antiviral properties. Riboflavin biosynthesis involving catalytic step of Lumazine synthase is absent in animals and human, but present in microorganism, one of marked advantage of this study. Still, this path is not exploited as antiinfective target. Here, we proposed different interactions between [1H,3H] imidazo[4,5-b] pyridine test ligands and target protein Lumazine synthase (protein Data Bank 2C92, one-step synthesis of title compounds and further evaluation of them for in vitro antimicrobial activity. Materials and Methods: Active pocket of the target protein involved in the interaction with the test ligands molecules was found using Biopredicta tools in VLifeMDS 4.3 Suite. In-silico docking suggests H-bonding, hydrophobic interaction, charge interaction, aromatic interaction, and Vanderwaal forces responsible for stabilizing enzyme-inhibitor complex. Disc diffusion assay method was used for in vitro antimicrobial screening. Results and Discussion: Investigation of possible interaction between test ligands and target lumazine synthase of Mycobacterium tuberculosis suggested 1i and 2f as best fit candidates showing hydrogen bonding, hydrophobic, aromatic and Vanderwaal′s forces. Among all derivatives 1g, 1j, 1k, 1l, 2a, 2c, 2d, 2e, 2h, and 2j exhibited potent activities against bacteria and fungi compared to the standard Ciprofloxacin and Fluconazole, respectively. The superiority of 1H imidazo [4,5-b] pyridine compounds having R′ = Cl >No 2 > NH 2 at the phenyl/aliphatic moiety resident on the imidazopyridine, whereas leading 3H imidazo[4,5-b] pyridine compounds containing R/Ar = Cl > No 2 > NH 2> OCH 3 substituents on the 2 nd position of imidazole.

  15. The Emerging Pathogen Candida auris: Growth Phenotype, Virulence Factors, Activity of Antifungals, and Effect of SCY-078, a Novel Glucan Synthesis Inhibitor, on Growth Morphology and Biofilm Formation.

    Science.gov (United States)

    Larkin, Emily; Hager, Christopher; Chandra, Jyotsna; Mukherjee, Pranab K; Retuerto, Mauricio; Salem, Iman; Long, Lisa; Isham, Nancy; Kovanda, Laura; Borroto-Esoda, Katyna; Wring, Steve; Angulo, David; Ghannoum, Mahmoud

    2017-05-01

    Candida auris , a new multidrug-resistant Candida spp. which is associated with invasive infection and high rates of mortality, has recently emerged. Here, we determined the virulence factors (germination, adherence, biofilm formation, phospholipase and proteinase production) of 16 C. auris isolates and their susceptibilities to 11 drugs belonging to different antifungal classes, including a novel orally bioavailable 1,3-β-d-glucan synthesis inhibitor (SCY-078). We also examined the effect of SCY-078 on the growth, ultrastructure, and biofilm-forming abilities of C. auris Our data showed that while the tested strains did not germinate, they did produce phospholipase and proteinase in a strain-dependent manner and had a significantly reduced ability to adhere and form biofilms compared to that of Candida albicans ( P = 0.01). C. auris isolates demonstrated reduced susceptibility to fluconazole and amphotericin B, while, in general, they were susceptible to the remaining drugs tested. SCY-078 had an MIC 90 of 1 mg/liter against C. auris and caused complete inhibition of the growth of C. auris and C. albicans Scanning electron microscopy analysis showed that SCY-078 interrupted C. auris cell division, with the organism forming abnormal fused fungal cells. Additionally, SCY-078 possessed potent antibiofilm activity, wherein treated biofilms demonstrated significantly reduced metabolic activity and a significantly reduced thickness compared to the untreated control ( P < 0.05 for both comparisons). Our study shows that C. auris expresses several virulence determinants (albeit to a lesser extent than C. albicans ) and is resistant to fluconazole and amphotericin B. SCY-078, the new orally bioavailable antifungal, had potent antifungal/antibiofilm activity against C. auris , indicating that further evaluation of this antifungal is warranted. Copyright © 2017 Larkin et al.

  16. Histone deacetylase inhibitors: can we consider potent anti-neoplastic agents for the treatment of asthma?

    Science.gov (United States)

    Royce, Simon G; Ververis, Katherine; Karagiannis, Tom C

    2012-01-01

    Histone deacetylase inhibitors have emerged as a new class of anti-cancer therapeutics due to their potent anti-proliferative and apoptotic effects in malignant cells. Accumulating evidence is indicating that histone deacetylase inhibitors may also have potential clinical utility in non-oncological applications, including asthma. However, the potential of histone deacetylase inhibitors in asthma remains controversial. For example, the mechanisms of action of the broad-spectrum histone deacetylase inhibitor, Trichostatin A, in animal models of allergic airways disease are conflicting. Further, there is evidence suggesting potential problems associated with histone deacetylase 2 inhibition and conventional glucocorticosteroid therapy. Similarly, disparate findings are emerging following modulation of the class III, sirtuin 1 enzyme. Indeed, it is becoming apparent that the mechanism of action may not be related to histone deacetylase inhibition activity per se. Further, there is only limited evidence that these compounds possess anti-inflammatory effects in models of asthma. In this review, we provide an overview of the biology of the metal-dependent and sirtuin deacetylases in the context of asthma. The controversies surrounding the potential use of histone deacetylase inhibitors in asthma are discussed and future directions involving the investigation of more specific analogues are explored.

  17. Fasting Induces Nuclear Factor E2-Related Factor 2 and ATP-Binding Cassette Transporters via Protein Kinase A and Sirtuin-1 in Mouse and Human

    Science.gov (United States)

    Kulkarni, Supriya R.; Donepudi, Ajay C.; Xu, Jialin; Wei, Wei; Cheng, Qiuqiong C.; Driscoll, Maureen V.; Johnson, Delinda A.; Johnson, Jeffrey A.; Li, Xiaoling

    2014-01-01

    Abstract Aims: The purpose of this study was to determine whether 3′-5′-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) and Sirtuin-1 (SIRT1) dependent mechanisms modulate ATP-binding Cassette (ABC) transport protein expression. ABC transport proteins (ABCC2–4) are essential for chemical elimination from hepatocytes and biliary excretion. Nuclear factor-E2 related-factor 2 (NRF2) is a transcription factor that mediates ABCC induction in response to chemical inducers and liver injury. However, a role for NRF2 in the regulation of transporter expression in nonchemical models of liver perturbation is largely undescribed. Results: Here we show that fasting increased NRF2 target gene expression through NRF2- and SIRT1–dependent mechanisms. In intact mouse liver, fasting induces NRF2 target gene expression by at least 1.5 to 5-fold. In mouse and human hepatocytes, treatment with 8-Bromoadenosine-cAMP, a cAMP analogue, increased NRF2 target gene expression and antioxidant response element activity, which was decreased by the PKA inhibitor, H-89. Moreover, fasting induced NRF2 target gene expression was decreased in liver and hepatocytes of SIRT1 liver-specific null mice and NRF2-null mice. Lastly, NRF2 and SIRT1 were recruited to MAREs and Antioxidant Response Elements (AREs) in the human ABCC2 promoter. Innovation: Oxidative stress mediated NRF2 activation is well described, yet the influence of basic metabolic processes on NRF2 activation is just emerging. Conclusion: The current data point toward a novel role of nutrient status in regulation of NRF2 activity and the antioxidant response, and indicates that cAMP/PKA and SIRT1 are upstream regulators for fasting-induced activation of the NRF2-ARE pathway. Antioxid. Redox Signal. 20, 15–30. PMID:23725046

  18. Sirtuin 1 regulates matrix metalloproteinase-13 expression induced by Porphyromonas endodontalis lipopolysaccharide via targeting nuclear factor–κB in osteoblasts

    Science.gov (United States)

    Qu, Liu; Yu, Yaqiong; Qiu, Lihong; Yang, Di; Yan, Lu; Guo, Jiajie; Jahan, Rabita

    2017-01-01

    ABSTRACT Porphyromonas endodontalis lipopolysaccharide (P.e LPS) is an important initiating factor for periapical inflammation and bone destruction. Matrix metalloproteinase-13 (MMP-13) has been shown to participate in the formation and diffusion of periapical bone lesion in chronic apical periodontitis. Sirtuin 1 (SIRT1) is a key regulator of inflammation in mammalian cells which suppresses the release of inflammatory mediators. This study aimed to explore the role of SIRT1 in regulating MMP-13 expression induced by P.e LPS in osteoblasts. P.e LPS stimulated MMP-13 expression in MC3T3-E1 cells. Knockdown of SIRT1 reinforced the increase of MMP-13mRNA expression induced by P.e LPS. SIRT1 activator resveratrol significantly reduced the expression of MMP-13 and SIRT1 inhibitor EX-527 enhanced the expression of MMP-13. Moreover, SIRT1 activation with resveratrol inhibited acetylation of NF-κB p65 and NF-κB transcriptional activity, which were enhanced by P.e LPS. In addition, NF-κB p65 was involved in P.e LPS-induced MMP-13 expression via directly binding to the MMP-13 promoter. However, SIRT1 activation significantly interfered with this binding. These findings strongly suggest that P.e LPS induces MMP-13 expression in osteoblasts, and SIRT1 suppresses this expression of MMP-13 through targeting NF-κB p65. This provides new insights into understanding the actions of SIRT1 on anti-inflammatory and anti-bone resorption activity. PMID:28473882

  19. Sirtuin 1 regulates matrix metalloproteinase-13 expression induced by Porphyromonas endodontalis lipopolysaccharide via targeting nuclear factor-κB in osteoblasts.

    Science.gov (United States)

    Qu, Liu; Yu, Yaqiong; Qiu, Lihong; Yang, Di; Yan, Lu; Guo, Jiajie; Jahan, Rabita

    2017-01-01

    Porphyromonas endodontalis lipopolysaccharide (P.e LPS) is an important initiating factor for periapical inflammation and bone destruction. Matrix metalloproteinase-13 (MMP-13) has been shown to participate in the formation and diffusion of periapical bone lesion in chronic apical periodontitis. Sirtuin 1 (SIRT1) is a key regulator of inflammation in mammalian cells which suppresses the release of inflammatory mediators. This study aimed to explore the role of SIRT1 in regulating MMP-13 expression induced by P.e LPS in osteoblasts. P.e LPS stimulated MMP-13 expression in MC3T3-E1 cells. Knockdown of SIRT1 reinforced the increase of MMP-13mRNA expression induced by P.e LPS. SIRT1 activator resveratrol significantly reduced the expression of MMP-13 and SIRT1 inhibitor EX-527 enhanced the expression of MMP-13. Moreover, SIRT1 activation with resveratrol inhibited acetylation of NF-κB p65 and NF-κB transcriptional activity, which were enhanced by P.e LPS. In addition, NF-κB p65 was involved in P.e LPS-induced MMP-13 expression via directly binding to the MMP-13 promoter. However, SIRT1 activation significantly interfered with this binding. These findings strongly suggest that P.e LPS induces MMP-13 expression in osteoblasts, and SIRT1 suppresses this expression of MMP-13 through targeting NF-κB p65. This provides new insights into understanding the actions of SIRT1 on anti-inflammatory and anti-bone resorption activity.

  20. The Activity of Sirtuin 1 in MCF-7 Breast Cancer Cell Line: The Effects of Visfatin

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    kiarash behrouzfar

    2015-11-01

    Full Text Available Background & Objectives: Breast cancer is the most common cancer and the second leading cause of cancer deaths among women. Obesity, hormones, and growth factors are the risk factors for this kind of cancer. One of the changes observed in patients suffering from breast cancer is the elevated Visfatin or nicotinamide phosphoribosyl transferase (NAMPT in their tumor tissues and blood. The increased activity of Visfatin and SIRT1 (Sirtuin 1 in breast cancer and many other cancers has been determined, and its value is correlated with cancer prognosis. The aim of the present study is to investigate the effects of Visfatin on SIRT1 activity in MCF-7 breast cancer cell line. Materials & Methods: In this study, in order to investigate the effects of Visfatin on SIRT1 activity in MCF-7 cells, cells were treated after cell culture by Visfatin for 12, 24, and 48 hours. Subsequently, the cells were lysed by nuclear extraction kit, and their total protein concentrations were measured by Bradford assay. Finally, we estimated the general activity of SIRT1 by measuring the SIRT1 activity with the assay kit via spectrofluorometric device. Results: The findings of this research show that SIRT1 activity is not significantly changed following Visfatin treatments for 12 and 24 hours. However, after 48 hour, Visfatin increases SIRT1 activity about 2 times more than control group. Conclusion: The antiapoptotic effects of Visfatin are exerted by increasing SIRT1 activity in MCF-7 cells, and these effects happen after 24 hours. 

  1. Sirtuin-2 Protects Neural Cells from Oxidative Stress and Is Elevated in Neurodegeneration

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    Preeti Singh

    2017-01-01

    Full Text Available Sirtuins are highly conserved lysine deacetylases involved in ageing, energy production, and lifespan extension. The mammalian SIRT2 has been implicated in Parkinson’s disease (PD where studies suggest SIRT2 promotes neurodegeneration. We therefore evaluated the effects of SIRT2 manipulation in toxin treated SH-SY5Y cells and determined the expression and activity of SIRT2 in postmortem brain tissue from patients with PD. SH-SY5Y viability in response to oxidative stress induced by diquat or rotenone was measured following SIRT2 overexpression or inhibition of deacetylase activity, along with α-synuclein aggregation. SIRT2 in human tissues was evaluated using Western blotting, immunohistochemistry, and fluorometric activity assays. In SH-SY5Y cells, elevated SIRT2 protected cells from rotenone or diquat induced cell death and enzymatic inhibition of SIRT2 enhanced cell death. SIRT2 protection was mediated, in part, through elevated SOD2 expression. SIRT2 reduced the formation of α-synuclein aggregates but showed minimal colocalisation with α-synuclein. In postmortem PD brain tissue, SIRT2 activity was elevated compared to controls but also elevated in other neurodegenerative disorders. Results from both in vitro work and brain tissue suggest that SIRT2 is necessary for protection against oxidative stress and higher SIRT2 activity in PD brain may be a compensatory mechanism to combat neuronal stress.

  2. Detection of Sirtuin-1 protein expression in peripheral blood leukocytes in dogs.

    Science.gov (United States)

    Yoshimura, Kuniko; Matsuu, Aya; Sasaki, Kai; Momoi, Yasuyuki

    2018-05-11

    Sirtuin-1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD + )-dependent histone deacetylase with a large number of protein substrates. It has attracted a lot of attention in association with extending lifespan. The objective of this study was to enable the evaluation of SIRT1 expression in peripheral blood mononuclear cells (PBMCs) from dogs by flow cytometry. Three transcript variants were amplified from PBMCs by reverse transcription PCR and the nucleotide sequences were analyzed. On the basis deduced amino acid sequence, a monoclonal antibody against human SIRT1, 1F3, was selected to detect canine SIRT1. Canine SIRT1 in peripheral blood mononuclear cells was successfully detected by western blotting using this antibody. Intracellular canine SIRT1 was also detected in permeabilized 293T cells transfected with a canine SIRT1 expression plasmid by flow cytometry using this antibody. SIRT1 was detected in all leukocyte subsets including lymphocytes, granulocytes and monocytes. The expression level was markedly different among individual dogs. These results indicated that the method applied in this study is useful for evaluating canine SIRT1 levels in PBMCs from dogs.

  3. Potential Mechanisms Linking Atherosclerosis and Increased Cardiovascular Risk in COPD: Focus On Sirtuins

    Science.gov (United States)

    Corbi, Graziamaria; Bianco, Andrea; Turchiarelli, Viviana; Cellurale, Michele; Fatica, Federica; Daniele, Aurora; Mazzarella, Gennaro; Ferrara, Nicola

    2013-01-01

    The development of atherosclerosis is a multi-step process, at least in part controlled by the vascular endothelium function. Observations in humans and experimental models of atherosclerosis have identified monocyte recruitment as an early event in atherogenesis. Chronic inflammation is associated with ageing and its related diseases (e.g., atherosclerosis and chronic obstructive pulmonary disease). Recently it has been discovered that Sirtuins (NAD+-dependent deacetylases) represent a pivotal regulator of longevity and health. They appear to have a prominent role in vascular biology and regulate aspects of age-dependent atherosclerosis. Many studies demonstrate that SIRT1 exhibits anti-inflammatory properties in vitro (e.g., fatty acid-induced inflammation), in vivo (e.g., atherosclerosis, sustainment of normal immune function in knock-out mice) and in clinical studies (e.g., patients with chronic obstructive pulmonary disease). Because of a significant reduction of SIRT1 in rodent lungs exposed to cigarette smoke and in lungs of patients with chronic obstructive pulmonary disease (COPD), activation of SIRT1 may be a potential target for chronic obstructive pulmonary disease therapy. We review the inflammatory mechanisms involved in COPD-CVD coexistence and the potential role of SIRT1 in the regulation of these systems. PMID:23774840

  4. Mitochondrial Sirtuin 4 Resolves Immune Tolerance in Monocytes by Rebalancing Glycolysis and Glucose Oxidation Homeostasis

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    Jie Tao

    2018-03-01

    Full Text Available The goal of this investigation was to define the molecular mechanism underlying physiologic conversion of immune tolerance to resolution of the acute inflammatory response, which is unknown. An example of this knowledge gap and its clinical importance is the broad-based energy deficit and immunometabolic paralysis in blood monocytes from non-survivors of human and mouse sepsis that precludes sepsis resolution. This immunometabolic dysregulation is biomarked by ex vivo endotoxin tolerance to increased glycolysis and TNF-α expression. To investigate how tolerance switches to resolution, we adapted our previously documented models associated with acute inflammatory, immune, and metabolic reprogramming that induces endotoxin tolerance as a model of sepsis in human monocytes. We report here that mitochondrial sirtuin 4 (SIRT4 physiologically breaks tolerance and resolves acute inflammation in human monocytes by coordinately reprogramming of metabolism and bioenergetics. We find that increased SIRT4 mRNA and protein expression during immune tolerance counters the increase in pyruvate dehydrogenase kinase 1 (PDK1 and SIRT1 that promote tolerance by switching glucose-dependent support of immune resistance to fatty acid oxidation support of immune tolerance. By decreasing PDK1, pyruvate dehydrogenase complex reactivation rebalances mitochondrial respiration, and by decreasing SIRT1, SIRT4 represses fatty acid oxidation. The precise mechanism for the mitochondrial SIRT4 nuclear feedback is unclear. Our findings are consistent with a new concept in which mitochondrial SIRT4 directs the axis that controls anabolic and catabolic energy sources.

  5. In situ synthesis, electrochemical and quantum chemical analysis of an amino acid-derived ionic liquid inhibitor for corrosion protection of mild steel in 1M HCl solution

    International Nuclear Information System (INIS)

    Kowsari, E.; Arman, S.Y.; Shahini, M.H.; Zandi, H.; Ehsani, A.; Naderi, R.; PourghasemiHanza, A.; Mehdipour, M.

    2016-01-01

    Highlights: • Electrochemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Quantum chemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Finding correlation between electrochemical analysis and quantum chemical analysis. - Abstract: In this study, an amino acid-derived ionic liquid inhibitor, namely tetra-n-butyl ammonium methioninate, was synthesized and the role this inhibitor for corrosion protection of mild steel exposed to 1.0 M HCl was investigated using electrochemical, quantum and surface analysis. By taking advantage of potentiodynamic polarization, the inhibitory action of tetra-n-butyl ammonium methioninate was found to be mainly mixed-type with dominant anodic inhibition. The effectiveness of the inhibitor was also indicated using electrochemical impedance spectroscopy (EIS). Moreover, to provide further insight into the mechanism of inhibition, electrochemical noise (EN) and quantum chemical calculations of the inhibitor were performed.

  6. Synthesis research of squalene synthetase inhibitor CP-263, 114. How is skeleton construction carried out?; Sukuaren gosei koso sogaizai CP-263,114 no gosei kenkyu - ikanishite kokkaku kochiku wo okonauka?

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Y. [Tokyo Inst. of Tech., Tokyo (Japan)

    2000-01-01

    CP-263, 114 isolated as a squalene synthetase inhibitor and the decyclization of CP-225, 917 was not only expected to be a lead chemical compound of the hypercholesterolemia medicine, but also have collected the attention of the organic synthetic chemistry researchers all over the world from the ring structure of advanced oxygen functionalization. In the CP- chemical compound, the constructive method of the bicyclo ring structure is a key of the synthesis, there are three reports to use the intramolecular Diels-Alder reaction (Fukuyama) and the siloxy-Cope rearrangement (Leighton), intramolecular Heck reaction (Danishefsky) as a result of succeeding in including the foothold to the side-chain lactol ring. Recently, Nicolaou et al. succeeded for the first time in the total synthesis racemic modification shell. They carried out the skeleton construction by the intramolecular Diels-Alder reaction, and constructed the maleic anhydride structure in taking the ketone as a foothold. (NEDO)

  7. HET0016, a selective inhibitor of 20-HETE synthesis, decreases pro-angiogenic factors and inhibits growth of triple negative breast cancer in mice.

    Directory of Open Access Journals (Sweden)

    Thaiz Ferraz Borin

    Full Text Available A selective inhibitor of 20-HETE synthesis, HET0016, has been reported to inhibit angiogenesis. 20-HETE has been known as a second mitogenic messenger of angiogenesis inducing growth factors. HET0016 effects were analyzed on MDA-MB-231 derived breast cancer in mouse and in vitro cell line. MDA-MB-231 tumor cells were implanted in animals' right flank and randomly assigned to early (1 and 2, starting treatments on day 0, or delayed groups (3 and 4 on day 8 after implantation of tumor. Animals received HET0016 (10 mg/kg treatment via intraperitoneal injection for 5 days/week for either 3 or 4 weeks. Control group received vehicle treatment. Tumor sizes were measured on days 7, 14, 21, and 28 and the animals were euthanized on day 22 and 29. Proteins were extracted from the whole tumor and from cells treated with 10 µM HET0016 for 4 and 24 hrs. Protein array kits of 20 different cytokines/factors were used. ELISA was performed to observe the HIF-1α and MMP-2 protein expression. Other markers were confirmed by IHC. HET0016 significantly inhibited tumor growth in all treatment groups at all-time points compared to control (p<0.05. Tumor growth was completely inhibited on three of ten animals on early treatment group. Treatment groups showed significantly lower expression of pro-angiogenic factors compared to control at 21 days; however, there was no significant difference in HIF-1α expression after treatments. Similar results were found in vitro at 24 hrs of HET0016 treatment. After 28 days, significant increase of angiogenin, angiopoietin-1/2, EGF-R and IGF-1 pro-angiogenic factors were found (p<0.05 compared to control, as well as an higher intensity of all factors were found when compared to that of 21 day's data, suggesting a treatment resistance. HET0016 inhibited tumor growth by reducing expression of different set of pro-angiogenic factors; however, a resistance to treatment seemed to happen after 21 days.

  8. Estrogen Receptor Driven Inhibitor Synthesis

    Science.gov (United States)

    2006-09-01

    chorion. High-cysteine content proteins have been reported in the chorion of Bombyx mori , with a proposed role in protecting the developing embryo from...73–80. [24] G.C. Rodakis, F.C. Kafatos, Origin of evolutionary novelty in proteins: how a high-cysteine chorion protein has evolved, Proc. Natl. Acad

  9. Lysine Deacetylase Inhibitors in Parasites: Past, Present, and Future Perspectives.

    Science.gov (United States)

    Hailu, Gebremedhin S; Robaa, Dina; Forgione, Mariantonietta; Sippl, Wolfgang; Rotili, Dante; Mai, Antonello

    2017-06-22

    Current therapies for human parasite infections rely on a few drugs, most of which have severe side effects, and their helpfulness is being seriously compromised by the drug resistance problem. Globally, this is pushing discovery research of antiparasitic drugs toward new agents endowed with new mechanisms of action. By using a "drug repurposing" strategy, histone deacetylase inhibitors (HDACi), which are presently clinically approved for cancer use, are now under investigation for various parasite infections. Because parasitic Zn 2+ - and NAD + -dependent HDACs play crucial roles in the modulation of parasite gene expression and many of them are pro-survival for several parasites under various conditions, they are now emerging as novel potential antiparasitic targets. This Perspective summarizes the state of knowledge of HDACi (both class I/II HDACi and sirtuin inhibitors) targeted to the main human parasitic diseases (schistosomiasis, malaria, trypanosomiasis, leishmaniasis, and toxoplasmosis) and provides visions into the main issues that challenge their development as antiparasitic agents.

  10. DGAT inhibitors for obesity.

    Science.gov (United States)

    Matsuda, Daisuke; Tomoda, Hiroshi

    2007-10-01

    Obesity is characterized by the accumulation of triacylglycerol in adipocytes. Diacylglycerol acyltransferase (DGAT) catalyzes the final reaction of triacylgycerol synthesis. Two isozymes of DGAT, DGAT1 and DGAT2, have been reported. Increased DGAT2 activity has a role in steatosis, while DGAT1 plays a role in very (V)LDL synthesis; increased plasma VLDL concentrations may promote obesity and thus DGAT1 is considered a potential therapeutic target of inhibition for obesity control. Several DGAT inhibitors of natural and synthetic origin have been reported, and their future prospect as anti-obesity drugs is discussed in this review.

  11. Sirtuins and resveratrol-derived compounds: a model for understanding the beneficial effects of the Mediterranean diet.

    Science.gov (United States)

    Russo, Matteo A; Sansone, Luigi; Polletta, Lucia; Runci, Alessandra; Rashid, Mohammad M; De Santis, Elena; Vernucci, Enza; Carnevale, Ilaria; Tafani, Marco

    2014-01-01

    The beneficial effects of the Mediterranean diet (MD) had been first observed about 50 years ago. Consumption of fresh vegetables and fruits, cereals, red wine, nuts, legumes, etc. has been regarded as the primary factor for protection from many human pathologies by the Mediterranean diet. Subsequently, this was attributed to the presence of polyphenols and their derivatives that, by exerting an anti-inflammatory and anti-oxidative effect, can be involved in the prevention of many diseases. Clinical trials, observational studies and meta-analysis have demonstrated an antiageing effect of MD accompanied by a reduced risk of age-related pathologies, such as cardiovascular, metabolic and neurodegenerative diseases, as well as cancer. The scientific explanation of such beneficial effects was limited to the reduction of the oxidative stress by compounds present in the MD. However, recently, this view is changing thanks to new studies aimed to uncover the molecular mechanism(s) activated by components of this diet. In particular, a new class of proteins called sirtuins have gained the attention of the scientific community because of their antiageing effects, their ability to protect from cardiovascular, metabolic, neurodegenerative diseases, cancer and to extend lifespan in lower organisms as well as in mammals. Interestingly, resveratrol a polyphenol present in grapes, nuts and berries has been shown to activate sirtuins and such activation is able to explain most of the beneficial effects of the MD. In this review, we will highlight the importance of MD with particular attention to the possible molecular pathways that have been shown to be influenced by it. We will describe the state of the art leading to demonstrate the important role of sirtuins as principal intracellular mediators of the beneficial effects of the MD. Finally, we will also introduce how Mediterranean diet may influence microbioma composition and stem cells function.

  12. Sirtuin1 and autophagy protect cells from fluoride-induced cell stress

    Science.gov (United States)

    Suzuki, Maiko; Bartlett, John D.

    2014-01-01

    Sirtuin1 (SIRT1) is an (NAD+)-dependent deacetylase functioning in the regulation of metabolism, cell survival and organismal lifespan. Active SIRT1 regulates autophagy during cell stress, including calorie restriction, endoplasmic reticulum stress and oxidative stress. Previously, we reported that fluoride induces endoplasmic reticulum (ER) stress in ameloblasts responsible for enamel formation, suggesting that ER-stress plays a role in dental fluorosis. However, the molecular mechanism of how cells respond to fluoride-induced cell stress is unclear. Here, we demonstrate that fluoride activates SIRT1 and initiates autophagy to protect cells from fluoride exposure. Fluoride treatment of ameloblast-derived cells (LS8) significantly increased Sirt1 expression and induced SIRT1 phosphorylation resulting in the augmentation of SIRT1 deacetylase activity. To demonstrate that fluoride exposure initiates autophagy, we characterized the expression of autophagy related genes (Atg); Atg5, Atg7 and Atg8/LC3 and showed that both their transcript and protein levels were significantly increased following fluoride treatment. To confirm that SIRT1 plays a protective role in fluoride toxicity, we used resveratrol (RES) to augmented SIRT1 activity in fluoride treated LS8 cells. RES increased autophagy, inhibited apoptosis, and decreased fluoride cytotoxicity. Rats treated with fluoride (0, 50 and 100 ppm) in drinking water for 6 weeks had significantly elevated expression levels of Sirt1, Atg5, Atg7 and Atg8/LC3 in their maturation stage enamel organs. Increased protein levels of p-SIRT1, ATG5 and ATG8/LC3 were present in fluoride-treated rat maturation stage ameloblasts. Therefore, the SIRT1/autophagy pathway may play a critical role as a protective response to help prevent dental fluorosis. PMID:24296261

  13. Sirtuin1 and autophagy protect cells from fluoride-induced cell stress.

    Science.gov (United States)

    Suzuki, Maiko; Bartlett, John D

    2014-02-01

    Sirtuin1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase functioning in the regulation of metabolism, cell survival and organismal lifespan. Active SIRT1 regulates autophagy during cell stress, including calorie restriction, endoplasmic reticulum (ER) stress and oxidative stress. Previously, we reported that fluoride induces ER-stress in ameloblasts responsible for enamel formation, suggesting that ER-stress plays a role in dental fluorosis. However, the molecular mechanism of how cells respond to fluoride-induced cell stress is unclear. Here, we demonstrate that fluoride activates SIRT1 and initiates autophagy to protect cells from fluoride exposure. Fluoride treatment of ameloblast-derived cells (LS8) significantly increased Sirt1 expression and induced SIRT1 phosphorylation resulting in the augmentation of SIRT1 deacetylase activity. To demonstrate that fluoride exposure initiates autophagy, we characterized the expression of autophagy related genes (Atg); Atg5, Atg7 and Atg8/LC3 and showed that both their transcript and protein levels were significantly increased following fluoride treatment. To confirm that SIRT1 plays a protective role in fluoride toxicity, we used resveratrol (RES) to augment SIRT1 activity in fluoride treated LS8 cells. RES increased autophagy, inhibited apoptosis, and decreased fluoride cytotoxicity. Rats treated with fluoride (0, 50, 100 and 125ppm) in drinking water for 6weeks had significantly elevated expression levels of Sirt1, Atg5, Atg7 and Atg8/LC3 in their maturation stage enamel organs. Increased protein levels of p-SIRT1, ATG5 and ATG8/LC3 were present in fluoride-treated rat maturation stage ameloblasts. Therefore, the SIRT1/autophagy pathway may play a critical role as a protective response to help prevent dental fluorosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Sirtuin signaling controls mitochondrial function in glycogen storage disease type Ia.

    Science.gov (United States)

    Cho, Jun-Ho; Kim, Goo-Young; Mansfield, Brian C; Chou, Janice Y

    2018-05-08

    Glycogen storage disease type Ia (GSD-Ia) deficient in glucose-6-phosphatase-α (G6Pase-α) is a metabolic disorder characterized by impaired glucose homeostasis and a long-term complication of hepatocellular adenoma/carcinoma (HCA/HCC). Mitochondrial dysfunction has been implicated in GSD-Ia but the underlying mechanism and its contribution to HCA/HCC development remain unclear. We have shown that hepatic G6Pase-α deficiency leads to downregulation of sirtuin 1 (SIRT1) signaling that underlies defective hepatic autophagy in GSD-Ia. SIRT1 is a NAD + -dependent deacetylase that can deacetylate and activate peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), a master regulator of mitochondrial integrity, biogenesis, and function. We hypothesized that downregulation of hepatic SIRT1 signaling in G6Pase-α-deficient livers impairs PGC-1α activity, leading to mitochondrial dysfunction. Here we show that the G6Pase-α-deficient livers display defective PGC-1α signaling, reduced numbers of functional mitochondria, and impaired oxidative phosphorylation. Overexpression of hepatic SIRT1 restores PGC-1α activity, normalizes the expression of electron transport chain components, and increases mitochondrial complex IV activity. We have previously shown that restoration of hepatic G6Pase-α expression normalized SIRT1 signaling. We now show that restoration of hepatic G6Pase-α expression also restores PGC-1α activity and mitochondrial function. Finally, we show that HCA/HCC lesions found in G6Pase-α-deficient livers contain marked mitochondrial and oxidative DNA damage. Taken together, our study shows that downregulation of hepatic SIRT1/PGC-1α signaling underlies mitochondrial dysfunction and that oxidative DNA damage incurred by damaged mitochondria may contribute to HCA/HCC development in GSD-Ia.

  15. Sirtuin 1 participates in the process of age-related retinal degeneration.

    Science.gov (United States)

    Zeng, Ying; Yang, Ke

    The process of aging involves retinal cell damage that leads to visual dysfunction. Sirtuin (Sirt) 1 can prevent oxidative stress, DNA damage, and apoptosis. In the present study, we measured the expression of Sirt1 as a functional regulator in the retina during the aging process. The visual function and Sirt1 expression in young (1 month) and old (19 months) Sprague-Dawley (SD) rats. Electroretinogram (ERG) and real-time polymerase chain reaction (PCR) or Western blotting were performed. Resveratrol, an activator of Sirt1, was orally administered to SD rats at a dose of 5 mg/kg/day for 19 months. The expression of Sirt1, brain-derived neurotrophic factor (BDNF), and tropomyosin receptor kinase B (TrkB) was evaluated in the retinas of mice that did and did not receive resveratrol treatment. Apoptosis was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. With decreasing b-wave amplitude, the expression level of Sirt1 was significantly reduced in aged retinas compared to that in young retinas. After 19 months of treatment with resveratrol, the Sirt1 expression level and b-wave amplitude increased. In old rats treated with resveratrol, the expression levels of BDNF and TrkB were up-regulated. Compared to young retinas, the aged retinas exhibited higher apoptosis, but resveratrol delayed this process. Our data demonstrated a reduction of Sirt1 expression during the aging process of the retina, but enhancing Sirt1 expression reversed the degeneration of the retina. These results suggested that increasing Sirt1 expression may protect retinal neurons and visual function via regulating neurotrophin and its receptor. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Thyroid hormone regulation of Sirtuin 1 expression and implications to integrated responses in fasted mice.

    Science.gov (United States)

    Cordeiro, Aline; de Souza, Luana Lopes; Oliveira, Lorraine Soares; Faustino, Larissa Costa; Santiago, Letícia Aragão; Bloise, Flavia Fonseca; Ortiga-Carvalho, Tania Maria; Almeida, Norma Aparecida Dos Santos; Pazos-Moura, Carmen Cabanelas

    2013-02-01

    Sirtuin 1 (SIRT1), a NAD(+)-dependent deacetylase, has been connected to beneficial effects elicited by calorie restriction. Physiological adaptation to starvation requires higher activity of SIRT1 and also the suppression of thyroid hormone (TH) action to achieve energy conservation. Here, we tested the hypothesis that those two events are correlated and that TH may be a regulator of SIRT1 expression. Forty-eight-hour fasting mice exhibited reduced serum TH and increased SIRT1 protein content in liver and brown adipose tissue (BAT), and physiological thyroxine replacement prevented or attenuated the increment of SIRT1 in liver and BAT of fasted mice. Hypothyroid mice exhibited increased liver SIRT1 protein, while hyperthyroid ones showed decreased SIRT1 in liver and BAT. In the liver, decreased protein is accompanied by reduced SIRT1 activity and no alteration in its mRNA. Hyperthyroid and hypothyroid mice exhibited increases and decreases in food intake and body weight gain respectively. Food-restricted hyperthyroid animals (pair-fed to euthyroid group) exhibited liver and BAT SIRT1 protein levels intermediary between euthyroid and hyperthyroid mice fed ad libitum. Mice with TH resistance at the liver presented increased hepatic SIRT1 protein and activity, with no alteration in Sirt1 mRNA. These results suggest that TH decreases SIRT1 protein, directly and indirectly, via food ingestion control and, in the liver, this reduction involves TRβ. The SIRT1 reduction induced by TH has important implication to integrated metabolic responses to fasting, as the increase in SIRT1 protein requires the fasting-associated suppression of TH serum levels.

  17. SRT1720, a sirtuin 1 activator, attenuates organ injury and inflammation in sepsis.

    Science.gov (United States)

    Khader, Adam; Yang, Weng-Lang; Hansen, Laura W; Rajayer, Salil R; Prince, Jose M; Nicastro, Jeffrey M; Coppa, Gene F; Wang, Ping

    2017-11-01

    Sepsis affects 800,000 patients in the United States annually with a mortality rate of up to 30%. Recent studies suggest that sepsis-associated metabolic derangements due to hypoxic tissue injury, impaired oxygen utilization, and mitochondrial dysfunction contribute to mortality. Sirtuin 1 (Sirt1) is a crucial modulator of energy metabolism during starvation states and has anti-inflammatory effects. Here, we hypothesized that SRT1720, a Sirt1 activator, could attenuate the severity of sepsis. Male C57BL/6 mice (20-25 g) were subjected to cecal ligation and puncture (CLP) to induce sepsis. SRT1720 (5 or 20 mg/kg BW) or 10% dimethyl sulfoxide (vehicle) in 0.2-mL saline was injected intravenously at 5 h after CLP. Control animals were not subjected to any surgery. Blood and liver samples were harvested at 20 h after CLP for analysis. Administration of SRT1720 markedly reduced the serum levels of tissue injury markers (aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase) and renal injury markers (blood urea nitrogen and creatinine) in a dose-dependent manner after CLP. Furthermore, the levels of proinflammatory cytokines interleukin (IL)-1β and IL-6 in the serum and liver were significantly inhibited by SRT1720 treatment after CLP. SRT1720 treatment resulted in a significantly decreased mRNA expression of inflammasome components (nucleotide oligomerization domain-like receptor protein 3, adapter apoptosis-associated speck-like protein containing caspase-recruitment domain, IL-1β, and IL-18) in the liver, compared with the vehicle group. SRT1720 treatment attenuates multiorgan injury in septic mice. SRT1720 treatment also decreases the production of proinflammatory cytokines and reduces inflammasome activation. Thus, pharmacologic stimulation of Sirt1 may present a promising therapeutic strategy for sepsis. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Design of novel HIV-1 protease inhibitors incorporating isophthalamide-derived P2-P3 ligands: Synthesis, biological evaluation and X-ray structural studies of inhibitor-HIV-1 protease complex

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Brindisi, Margherita; Nyalapatla, Prasanth R.; Takayama, Jun; Ella-Menye, Jean-Rene; Yashchuk, Sofiya; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Amano, Masayuki; Weber, Irene T.; Mitsuya, Hiroaki

    2017-10-01

    Based upon molecular insights from the X-ray structures of inhibitor-bound HIV-1 protease complexes, we have designed a series of isophthalamide-derived inhibitors incorporating substituted pyrrolidines, piperidines and thiazolidines as P2-P3 ligands for specific interactions in the S2-S3 extended site. Compound 4b has shown an enzyme Ki of 0.025 nM and antiviral IC50 of 69 nM. An X-ray crystal structure of inhibitor 4b-HIV-1 protease complex was determined at 1.33 Å resolution. We have also determined X-ray structure of 3b-bound HIV-1 protease at 1.27 Å resolution. These structures revealed important molecular insight into the inhibitor–HIV-1 protease interactions in the active site.

  19. Improved synthesis of (3E,6Z,9Z)-1,3,6,9-nonadecatetraene, attraction inhibitor of bruce spanworm, Operophtera bruceata, to pheromone traps for monitoring winter moth, Operophtera brumata.

    Science.gov (United States)

    Khrimian, Ashot; Lance, David R; Mastro, Victor C; Elkinton, Joseph S

    2010-02-10

    The winter moth, Operophtera brumata (Lepidoptera: Geometridae), is an early-season defoliator that attacks a wide variety of hardwoods and, in some cases, conifers. The insect is native to Europe but has become established in at least three areas of North America including southeastern New England. The female-produced sex attractant pheromone of the winter moth was identified as (3Z,6Z,9Z)-1,3,6,9-nonadecatetraene (1), which also attracts a native congener, the Bruce spanworm, Operophtera bruceata . Dissection, or (for certainty) DNA molecular testing, is required to differentiate between males of the two species. Thus, a trapping method that is selective for winter moth would be desirable. A geometric isomer of the pheromone, (3E,6Z,9Z)-1,3,6,9-nonadecatetraene (2), can reportedly inhibit attraction of Bruce spanworm to traps without affecting winter moth catch, but use of the pheromone and inhibitor together has not been optimized, nor has the synthesis of the inhibitor. This paper presents two new syntheses of the inhibitor (3E,6Z,9Z)-1,3,6,9-nonadecatetraene based on the intermediate (3Z,6Z)-3,6-hexadecadien-1-ol (4), which has also been utilized in the synthesis of the pheromone. The syntheses combine traditional acetylenic chemistry and Wittig olefination reactions. In one approach, 2 was synthesized in 80% purity (20% being pheromone 1), and in the second, tetraene 2 of 96% purity (and free of 1) was produced in 25% overall yield from dienol 4. The last method benefitted from a refined TEMPO-mediated PhI(OAc)(2) oxidation of 4 and a two-carbon homologation of the corresponding aldehyde 7.

  20. Synthesis of a Potent Aminopyridine-Based nNOS-Inhibitor by Two Recent No-Carrier-Added $^{18}$F-Labelling Methods

    OpenAIRE

    Drerup, Christian; Ermert, Johannes; Coenen, Heinrich Hubert

    2016-01-01

    Nitric oxide (NO), an important multifunctional signaling molecule, is produced by three isoforms of NO-synthase (NOS) and has been associated with neurodegenerative disorders. Selective inhibitors of the subtypes iNOS (inducible) or nNOS (neuronal) are of great interest for decoding neurodestructive key factors, and 18F-labelled analogues would allow investigating the NOS-function by molecular imaging with positron emission tomography. Especially, the highly selective nNOS inhibitor 6-((3-((...

  1. The impact of cofactors and inhibitors on DNA repair synthesis after γ-irradiation in semi-permeable Escherichia coli cells

    International Nuclear Information System (INIS)

    Gaertner, C.

    1981-01-01

    The DNA-repair synthesis in tuluol-permeable E. coli cells after γ-irradiation has been investigated in dependence on the co-facotrs. ATB and NAD by means of enzyme kinetics. A partly repair-deficient mutants were taken into consideration which are well characterized in view of molecular biology; they showed which enzyme functions participate in the γ-induced DNA repair synthesis. The inhibition of the DNA-repair synthesis by the intercalary substances Adriamycin and Proflavin has been described and compared with the survival rates after irradiation and after combined treatment by irradiation and intercalary agents. (orig./AJ) [de

  2. Combination of vatalanib and a 20-HETE synthesis inhibitor results in decreased tumor growth in an animal model of human glioma

    Directory of Open Access Journals (Sweden)

    Shankar A

    2016-03-01

    Full Text Available Adarsh Shankar,1 Thaiz F Borin,2 Asm Iskander,1 Nadimpalli RS Varma,3 Bhagelu R Achyut,1 Meenu Jain,1 Tom Mikkelsen,4 Austin M Guo,5 Wilson B Chwang,3 James R Ewing,6 Hassan Bagher-Ebadian,6 Ali S Arbab11Tumor Angiogenesis Laboratory, Cancer Center, Georgia Regents University, Augusta, GA, USA; 2Laboratory of Molecular Investigation of Cancer (LIMC, Faculty of Medicine of Sao Jose do Rio Preto, Sao Jose do Rio Preto, Brazil; 3Department of Radiology, Cellular and Molecular Imaging Laboratory, 4Department of Neurosurgery, Henry Ford Health System, Detroit, MI, 5Department of Pharmacology, New York Medical College, Valhalla, NY, 6Department of Neurology and Radiology, Henry Ford Health System, Detroit, MI, USA Background: Due to the hypervascular nature of glioblastoma (GBM, antiangiogenic treatments, such as vatalanib, have been added as an adjuvant to control angiogenesis and tumor growth. However, evidence of progressive tumor growth and resistance to antiangiogenic treatment has been observed. To counter the unwanted effect of vatalanib on GBM growth, we have added a new agent known as N-hydroxy-N'-(4-butyl-2 methylphenylformamidine (HET0016, which is a selective inhibitor of 20-hydroxyeicosatetraenoic acid (20-HETE synthesis. The aims of the studies were to determine 1 whether the addition of HET0016 can attenuate the unwanted effect of vatalanib on tumor growth and 2 whether the treatment schedule would have a crucial impact on controlling GBM.Methods: U251 human glioma cells (4×105 were implanted orthotopically. Two different treatment schedules were investigated. Treatment starting on day 8 (8–21 days treatment of the tumor implantation was to mimic treatment following detection of tumor, where tumor would have hypoxic microenvironment and well-developed neovascularization. Drug treatment starting on the same day of tumor implantation (0–21 days treatment was to mimic cases following radiation therapy or surgery. There were four

  3. Sirtuin 6 prevents matrix degradation through inhibition of the NF-κB pathway in intervertebral disc degeneration

    International Nuclear Information System (INIS)

    Kang, Liang; Hu, Jia; Weng, Yuxiong; Jia, Jie; Zhang, Yukun

    2017-01-01

    Intervertebral disc degeneration (IDD) is marked by imbalanced metabolism of the extracellular matrix (ECM) in the nucleus pulposus (NP) of intervertebral discs. This study aimed to determine whether sirtuin 6 (SIRT6), a member of the sirtuin family of nicotinamide adenine dinucleotide-dependent deacetylases, protects the NP from ECM degradation in IDD. Our study showed that expression of SIRT6 markedly decreased during IDD progression. Overexpression of wild-type SIRT6, but not a catalytically inactive mutant, prevented IL-1β-induced NP ECM degradation. SIRT6 depletion by RNA interference in NP cells caused ECM degradation. Moreover, SIRT6 physically interacted with nuclear factor-κB (NF-κB) catalytic subunit p65, transcriptional activity of which was significantly suppressed by SIRT6 overexpression. These results suggest that SIRT6 prevented NP ECM degradation in vitro via inhibiting NF-κB-dependent transcriptional activity and that this effect depended on its deacetylase activity. - Highlights: • SIRT6 expression is decreased in degenerative nucleus pulposus (NP) tissues. • SIRT6 overexpression lowers IL-1β-induced matrix degradation of NP. • SIRT6 inhibition induces matrix degradation of NP. • SIRT6 prevents matrix degradation of NP via the NF-κB signaling pathway.

  4. Sirtuin 6 prevents matrix degradation through inhibition of the NF-κB pathway in intervertebral disc degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Liang [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Hu, Jia [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Weng, Yuxiong [Department of Hand Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Jia, Jie [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zhang, Yukun, E-mail: zhangyukuncom@126.com [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China)

    2017-03-15

    Intervertebral disc degeneration (IDD) is marked by imbalanced metabolism of the extracellular matrix (ECM) in the nucleus pulposus (NP) of intervertebral discs. This study aimed to determine whether sirtuin 6 (SIRT6), a member of the sirtuin family of nicotinamide adenine dinucleotide-dependent deacetylases, protects the NP from ECM degradation in IDD. Our study showed that expression of SIRT6 markedly decreased during IDD progression. Overexpression of wild-type SIRT6, but not a catalytically inactive mutant, prevented IL-1β-induced NP ECM degradation. SIRT6 depletion by RNA interference in NP cells caused ECM degradation. Moreover, SIRT6 physically interacted with nuclear factor-κB (NF-κB) catalytic subunit p65, transcriptional activity of which was significantly suppressed by SIRT6 overexpression. These results suggest that SIRT6 prevented NP ECM degradation in vitro via inhibiting NF-κB-dependent transcriptional activity and that this effect depended on its deacetylase activity. - Highlights: • SIRT6 expression is decreased in degenerative nucleus pulposus (NP) tissues. • SIRT6 overexpression lowers IL-1β-induced matrix degradation of NP. • SIRT6 inhibition induces matrix degradation of NP. • SIRT6 prevents matrix degradation of NP via the NF-κB signaling pathway.

  5. Adaptive response to chronic mild ethanol stress involves ROS, sirtuins and changes in chromosome dosage in wine yeasts.

    Science.gov (United States)

    Adamczyk, Jagoda; Deregowska, Anna; Skoneczny, Marek; Skoneczna, Adrianna; Kwiatkowska, Aleksandra; Potocki, Leszek; Rawska, Ewa; Pabian, Sylwia; Kaplan, Jakub; Lewinska, Anna; Wnuk, Maciej

    2016-05-24

    Industrial yeast strains of economic importance used in winemaking and beer production are genomically diverse and subjected to harsh environmental conditions during fermentation. In the present study, we investigated wine yeast adaptation to chronic mild alcohol stress when cells were cultured for 100 generations in the presence of non-cytotoxic ethanol concentration. Ethanol-induced reactive oxygen species (ROS) and superoxide signals promoted growth rate during passages that was accompanied by increased expression of sirtuin proteins, Sir1, Sir2 and Sir3, and DNA-binding transcription regulator Rap1. Genome-wide array-CGH analysis revealed that yeast genome was shaped during passages. The gains of chromosomes I, III and VI and significant changes in the gene copy number in nine functional gene categories involved in metabolic processes and stress responses were observed. Ethanol-mediated gains of YRF1 and CUP1 genes were the most accented. Ethanol also induced nucleolus fragmentation that confirms that nucleolus is a stress sensor in yeasts. Taken together, we postulate that wine yeasts of different origin may adapt to mild alcohol stress by shifts in intracellular redox state promoting growth capacity, upregulation of key regulators of longevity, namely sirtuins and changes in the dosage of genes involved in the telomere maintenance and ion detoxification.

  6. Altered cellular redox status, sirtuin abundance and clock gene expression in a mouse model of developmentally primed NASH.

    Science.gov (United States)

    Bruce, Kimberley D; Szczepankiewicz, Dawid; Sihota, Kiran K; Ravindraanandan, Manoj; Thomas, Hugh; Lillycrop, Karen A; Burdge, Graham C; Hanson, Mark A; Byrne, Christopher D; Cagampang, Felino R

    2016-07-01

    We have previously shown that high fat (HF) feeding during pregnancy primes the development of non-alcoholic steatohepatits (NASH) in the adult offspring. However, the underlying mechanisms are unclear. Since the endogenous molecular clock can regulate hepatic lipid metabolism, we investigated whether exposure to a HF diet during development could alter hepatic clock gene expression and contribute to NASH onset in later life. Female mice were fed either a control (C, 7%kcal fat) or HF (45%kcal fat) diet. Offspring were fed either a C or HF diet resulting in four offspring groups: C/C, C/HF, HF/C and HF/HF. NAFLD progression, cellular redox status, sirtuin expression (Sirt1, Sirt3), and the expression of core clock genes (Clock, Bmal1, Per2, Cry2) and clock-controlled genes involved in lipid metabolism (Rev-Erbα, Rev-Erbβ, RORα, and Srebp1c) were measured in offspring livers. Offspring fed a HF diet developed NAFLD. However HF fed offspring of mothers fed a HF diet developed NASH, coupled with significantly reduced NAD(+)/NADH (pNASH in adulthood, involving altered cellular redox status, reduced sirtuin abundance, and desynchronized clock gene expression. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. General synthesis of β-alanine-containing spider polyamine toxins and discovery of nephila polyamine toxins 1 and 8 as highly potent inhibitors of ionotropic glutamate receptors

    DEFF Research Database (Denmark)

    Lucas, Simon; Poulsen, Mette H; Nørager, Niels G

    2012-01-01

    Certain spiders contain large pools of polyamine toxins, which are putative pharmacological tools awaiting further discovery. Here we present a general synthesis strategy for this class of toxins and prepare five structurally varied polyamine toxins. Electrophysiological testing at three ionotrop...

  8. Design, synthesis and crystallographic analysis of nitrile-based broad-spectrum peptidomimetic inhibitors for coronavirus 3C-like proteases.

    Science.gov (United States)

    Chuck, Chi-Pang; Chen, Chao; Ke, Zhihai; Wan, David Chi-Cheong; Chow, Hak-Fun; Wong, Kam-Bo

    2013-01-01

    Coronaviral infection is associated with up to 5% of respiratory tract diseases. The 3C-like protease (3CL(pro)) of coronaviruses is required for proteolytic processing of polyproteins and viral replication, and is a promising target for the development of drugs against coronaviral infection. We designed and synthesized four nitrile-based peptidomimetic inhibitors with different N-terminal protective groups and different peptide length, and examined their inhibitory effect on the in-vitro enzymatic activity of 3CL(pro) of severe-acute-respiratory-syndrome-coronavirus. The IC(50) values of the inhibitors were in the range of 4.6-49 μM, demonstrating that the nitrile warhead can effectively inactivate the 3CL(pro) autocleavage process. The best inhibitor, Cbz-AVLQ-CN with an N-terminal carbobenzyloxy group, was ~10x more potent than the other inhibitors tested. Crystal structures of the enzyme-inhibitor complexes showed that the nitrile warhead inhibits 3CL(pro) by forming a covalent bond with the catalytic Cys145 residue, while the AVLQ peptide forms a number of favourable interactions with the S1-S4 substrate-binding pockets. We have further showed that the peptidomimetic inhibitor, Cbz-AVLQ-CN, has broad-spectrum inhibition against 3CL(pro) from human coronavirus strains 229E, NL63, OC43, HKU1, and infectious bronchitis virus, with IC(50) values ranging from 1.3 to 3.7 μM, but no detectable inhibition against caspase-3. In summary, we have shown that the nitrile-based peptidomimetic inhibitors are effective against 3CL(pro), and they inhibit 3CL(pro) from a broad range of coronaviruses. Our results provide further insights into the future design of drugs that could serve as a first line defence against coronaviral infection. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  9. Novel diamide-based inhibitors of IMPDH.

    Science.gov (United States)

    Gu, Henry H; Iwanowicz, Edwin J; Guo, Junqing; Watterson, Scott H; Shen, Zhongqi; Pitts, William J; Dhar, T G Murali; Fleener, Catherine A; Rouleau, Katherine; Sherbina, N Z; Witmer, Mark; Tredup, Jeffrey; Hollenbaugh, Diane

    2002-05-06

    A series of novel amide-based small molecule inhibitors of inosine monophosphate dehydrogenase is described. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are presented.

  10. Accurate quantification of site-specific acetylation stoichiometry reveals the impact of sirtuin deacetylase CobB on the E. coli acetylome

    DEFF Research Database (Denmark)

    Weinert, Brian Tate; Satpathy, Shankha; Hansen, Bogi Karbech

    2017-01-01

    B suppressed acetylation to lower than median stoichiometry in WT, ptaΔ, and ackAΔ cells. Together, our results provide a detailed view of acetylation stoichiometry in E. coli and suggest an evolutionarily conserved function of Sirtuin deacetylases in suppressing low stoichiometry acetylation....

  11. Synthesis, biological evaluation and molecular modeling of a novel series of 7-azaindole based tri-heterocyclic compounds as potent CDK2/Cyclin E inhibitors

    Czech Academy of Sciences Publication Activity Database

    Baltus, C.B.; Jorda, Radek; Marot, Ch.; Berka, K.; Bazgier, Václav; Kryštof, Vladimír; Prie, G.; Viaud-Massuard, M.C.

    2016-01-01

    Roč. 108, JAN 27 (2016), s. 701-719 ISSN 0223-5234 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Cyclin-dependent kinase 2 * Kinase inhibitors * Anti-tumor agent Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.519, year: 2016

  12. Targeting Type 2 Diabetes with C-Glucosyl Dihydrochalcones as Selective Sodium Glucose Co-Transporter 2 (SGLT2) Inhibitors: Synthesis and Biological Evaluation.

    Science.gov (United States)

    Jesus, Ana R; Vila-Viçosa, Diogo; Machuqueiro, Miguel; Marques, Ana P; Dore, Timothy M; Rauter, Amélia P

    2017-01-26

    Inhibiting glucose reabsorption by sodium glucose co-transporter proteins (SGLTs) in the kidneys is a relatively new strategy for treating type 2 diabetes. Selective inhibition of SGLT2 over SGLT1 is critical for minimizing adverse side effects associated with SGLT1 inhibition. A library of C-glucosyl dihydrochalcones and their dihydrochalcone and chalcone precursors was synthesized and tested as SGLT1/SGLT2 inhibitors using a cell-based fluorescence assay of glucose uptake. The most potent inhibitors of SGLT2 (IC 50 = 9-23 nM) were considerably weaker inhibitors of SGLT1 (IC 50 = 10-19 μM). They showed no effect on the sodium independent GLUT family of glucose transporters, and the most potent ones were not acutely toxic to cultured cells. The interaction of a C-glucosyl dihydrochalcone with a POPC membrane was modeled computationally, providing evidence that it is not a pan-assay interference compound. These results point toward the discovery of structures that are potent and highly selective inhibitors of SGLT2.

  13. Synthesis, molecular docking and biological evaluation as HDAC inhibitors of cyclopeptide mimetics by a tandem three-component reaction and intramolecular [3+2] cycloaddition.

    Science.gov (United States)

    Pirali, Tracey; Faccio, Valeria; Mossetti, Riccardo; Grolla, Ambra A; Di Micco, Simone; Bifulco, Giuseppe; Genazzani, Armando A; Tron, Gian Cesare

    2010-02-01

    Novel macrocyclic peptide mimetics have been synthesized by exploiting a three-component reaction and an azide-alkyne [3 + 2] cycloaddition. The prepared compounds were screened as HDAC inhibitors allowing us to identify a new compound with promising biological activity. In order to rationalize the biological results, computational studies have also been performed.

  14. Synthesis and evaluation of "AZT-HEPT", "AZT-pyridinone", and "ddC-HEPT" conjugates as inhibitors of HIV reverse transcriptase.

    Science.gov (United States)

    Pontikis, R; Dollé, V; Guillaumel, J; Dechaux, E; Note, R; Nguyen, C H; Legraverend, M; Bisagni, E; Aubertin, A M; Grierson, D S; Monneret, C

    2000-05-18

    To test the concept that HIV reverse transcriptase could be effectively inhibited by "mixed site inhibitors", a series of seven conjugates containing both a nucleoside analogue component (AZT 1, ddC 2) and a nonnucleoside type inhibitor (HEPT analogue 12, pyridinone 27) were synthesized and evaluated for their ability to block HIV replication. The (N-3 and C-5)AZT-HEPT conjugates 15, 22, and 23 displayed 2-5 microM anti-HIV activity, but they had no effect on the replication of HIV-2 or the HIV-1 strain with the Y181C mutation. The (C-5)AZT-pyridinone conjugates 34-37 were found to be inactive. In marked contrast, the ddC-HEPT molecule 26 displayed the same potency (EC(50) = 0.45 microM) against HIV-1 (wild type and the Y181C nevirapine-resistant strain) and HIV-2 in cell culture. No synergistic effect was observed for these bis-substrate inhibitors, suggesting that the two individual inhibitor components in these molecules do not bind simultaneously in their respective sites. Interestingly, however, the results indicate that the AZT-HEPT conjugates and the ddC-HEPT derivative 26 inhibit reverse transcriptase (RT) in an opposite manner. One explanation for this difference is that the former compounds interact preferentially with the hydrophobic pocket in RT, whereas 26 (after supposed triphosphorylation) inhibits RT through binding in the catalytic site.

  15. Simultaneous initiation (coinitiation) of pharmacotherapy with triiodothyronine and a selective serotonin reuptake inhibitor for major depressive disorder: a quantitative synthesis of double-blind studies

    NARCIS (Netherlands)

    Papakostas, George I.; Cooper-Kazaz, Rena; Appelhof, Bente C.; Posternak, Michael A.; Johnson, Daniel P.; Klibanski, Anne; Lerer, Bernard; Fava, Maurizio

    2009-01-01

    To examine the efficacy and overall tolerability of the simultaneous initiation of treatment (coinitiation) with triiodothyronine (T3) and a selective serotonin reuptake inhibitor (SSRI) for major depressive disorder (MDD). Sources of date were Medline/Pubmed, EMBASE, the Cochrane database, and

  16. Synthesis and evaluation of symmetric acyclic nucleoside bisphosphonates as inhibitors of the Plasmodium falciparum, Plasmodium vivax and human 6-oxopurine phosphoribosyltransferases and the antimalarial activity of their prodrugs

    Czech Academy of Sciences Publication Activity Database

    Špaček, Petr; Keough, D. T.; Chavchich, M.; Dračínský, Martin; Janeba, Zlatko; Naesens, L.; Edstein, M. D.; Guddat, L. W.; Hocková, Dana

    2017-01-01

    Roč. 25, č. 15 (2017), s. 4008-4030 ISSN 0968-0896 R&D Projects: GA ČR(CZ) GA16-06049S Institutional support: RVO:61388963 Keywords : enzyme inhibitors * nucleotide analogues * malaria Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.930, year: 2016

  17. Synthesis of a Potent Aminopyridine-Based nNOS-Inhibitor by Two Recent No-Carrier-Added 18F-Labelling Methods

    Directory of Open Access Journals (Sweden)

    Christian Drerup

    2016-09-01

    Full Text Available Nitric oxide (NO, an important multifunctional signaling molecule, is produced by three isoforms of NO-synthase (NOS and has been associated with neurodegenerative disorders. Selective inhibitors of the subtypes iNOS (inducible or nNOS (neuronal are of great interest for decoding neurodestructive key factors, and 18F-labelled analogues would allow investigating the NOS-function by molecular imaging with positron emission tomography. Especially, the highly selective nNOS inhibitor 6-((3-((3-fluorophenethylaminomethylphenoxymethyl-4-methylpyridin-2-amine (10 lends itself as suitable compound to be 18F-labelled in no-carrier-added (n.c.a. form. For preparation of the 18F-labelled nNOS-Inhibitor [18F]10 a “build-up” radiosynthesis was developed based on a corresponding iodonium ylide as labelling precursor. The such activated phenethyl group of the compound was efficiently and regioselectively labelled with n.c.a. [18F]fluoride in 79% radiochemical yield (RCY. After conversion by reductive amination and microwave assisted displacement of the protecting groups, the desired nNOS-inhibitor was obtained in about 15% total RCY. Alternatively, for a simplified “late-stage” 18F-labelling procedure a corresponding boronic ester precursor was synthesized and successfully used in a newer, copper(II mediated n.c.a. 18F-fluoro-deboroniation reaction, achieving the same total RCY. Thus, both methods proved comparatively suited to provide the highly selective NOS-inhibitor [18F]10 as probe for preclinical in vivo studies.

  18. Synthesis of a Potent Aminopyridine-Based nNOS-Inhibitor by Two Recent No-Carrier-Added (18)F-Labelling Methods.

    Science.gov (United States)

    Drerup, Christian; Ermert, Johannes; Coenen, Heinz H

    2016-09-01

    Nitric oxide (NO), an important multifunctional signaling molecule, is produced by three isoforms of NO-synthase (NOS) and has been associated with neurodegenerative disorders. Selective inhibitors of the subtypes iNOS (inducible) or nNOS (neuronal) are of great interest for decoding neurodestructive key factors, and (18)F-labelled analogues would allow investigating the NOS-function by molecular imaging with positron emission tomography. Especially, the highly selective nNOS inhibitor 6-((3-((3-fluorophenethylamino)methyl)phenoxy)methyl)-4-methylpyridin-2-amine (10) lends itself as suitable compound to be (18)F-labelled in no-carrier-added (n.c.a.) form. For preparation of the (18)F-labelled nNOS-Inhibitor [(18)F]10 a "build-up" radiosynthesis was developed based on a corresponding iodonium ylide as labelling precursor. The such activated phenethyl group of the compound was efficiently and regioselectively labelled with n.c.a. [(18)F]fluoride in 79% radiochemical yield (RCY). After conversion by reductive amination and microwave assisted displacement of the protecting groups, the desired nNOS-inhibitor was obtained in about 15% total RCY. Alternatively, for a simplified "late-stage" (18)F-labelling procedure a corresponding boronic ester precursor was synthesized and successfully used in a newer, copper(II) mediated n.c.a. (18)F-fluoro-deboroniation reaction, achieving the same total RCY. Thus, both methods proved comparatively suited to provide the highly selective NOS-inhibitor [(18)F]10 as probe for preclinical in vivo studies.

  19. Sirtuin-3 (Sirt3) regulates skeletal muscle metabolism and insulin signaling via altered mitochondrial oxidation and reactive oxygen species production

    DEFF Research Database (Denmark)

    Jing, Enxuan; Emanuelli, Brice; Hirschey, Matthew D

    2011-01-01

    Sirt3 is a member of the sirtuin family of protein deacetylases that is localized in mitochondria and regulates mitochondrial function. Sirt3 expression in skeletal muscle is decreased in models of type 1 and type 2 diabetes and regulated by feeding, fasting, and caloric restriction. Sirt3 knockout...... mice exhibit decreased oxygen consumption and develop oxidative stress in skeletal muscle, leading to JNK activation and impaired insulin signaling. This effect is mimicked by knockdown of Sirt3 in cultured myoblasts, which exhibit reduced mitochondrial oxidation, increased reactive oxygen species......, activation of JNK, increased serine and decreased tyrosine phosphorylation of IRS-1, and decreased insulin signaling. Thus, Sirt3 plays an important role in diabetes through regulation of mitochondrial oxidation, reactive oxygen species production, and insulin resistance in skeletal muscle....

  20. Synthesis and biological evaluation of some N-(3-(1H-tetrazol-5-yl) phenyl)acetamide derivatives as novel non-carboxylic PTP1B inhibitors designed through bioisosteric modulation.

    Science.gov (United States)

    Maheshwari, Neelesh; Karthikeyan, Chandrabose; Bhadada, Shraddha V; Sahi, Chandan; Verma, Amit K; Hari Narayana Moorthy, N S; Trivedi, Piyush

    2018-06-08

    Described herein is the synthesis and biological evaluation of a series of non-carboxylic inhibitors of Protein Tyrosine Phosphatase 1B designed using bioisosteric replacement strategy. Six N-(3-(1H-tetrazol-5-yl)phenyl)acetamide derivatives designed employing the aforementioned strategy were synthesized and screened for PTP1B inhibitory activity. Among the synthesized compounds, compound NM-03 exhibited the most potent inhibitory activity with IC 50 value of 4.48 µM. Docking studies with NM-03 revealed the key interactions with desired amino acids in the binding site of PTP1B. Furthermore, compound NM-03 also elicited good in vivo activity. Taken together, the results of this study establish N-(3-(1H-tetrazole-5-yl)phenyl)-2-(benzo[d]oxazol-2-ylthio)acetamide (NM-03) as a valuable lead molecule with great potential for PTP1B inhibitor development targeting diabetes. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Sirtuin1 single nucleotide polymorphism (A2191G is a diagnostic marker for vibration-induced white finger disease

    Directory of Open Access Journals (Sweden)

    Voelter-Mahlknecht Susanne

    2012-10-01

    Full Text Available Abstract Background Vibration-induced white finger disease (VWF, also known as hand-arm vibration syndrome, is a secondary form of Raynaud’s disease, affecting the blood vessels and nerves. So far, little is known about the pathogenesisof the disease. VWF is associated with an episodic reduction in peripheral blood flow. Sirtuin 1, a class III histone deacetylase, has been described to regulate the endothelium dependent vasodilation by targeting endothelial nitric oxide synthase. We assessed Sirt1single nucleotide polymorphisms in patients with VWF to further elucidate the role of sirtuin 1 in the pathogenesis of VWF. Methods Peripheral blood samples were obtained from 74 patients with VWF (male 93.2%, female 6.8%, median age 53 years and from 317 healthy volunteers (gender equally distributed, below 30 years of age. Genomic DNA was extracted from peripheral blood mononuclear cells and screened for potential Sirt1single nucleotide polymorphisms. Four putative genetic polymorphisms out of 113 within the Sirt1 genomic region (NCBI Gene Reference: NM_012238.3 were assessed. Allelic discrimination was performed by TaqMan-polymerasechainreaction-based allele-specific genotyping single nucleotide polymorphism assays. Results Sirt1single nucleotide polymorphism A2191G (Assay C_25611590_10, rs35224060 was identified within Sirt1 exon 9 (amino acid position 731, Ile → Val, with differing allelic frequencies in the VWF population (A/A: 70.5%, A/G: 29.5%, G/G: 0% and the control population (A/A: 99.7%, A/G: 0.3%, G/G: 0.5%, with significance levels of P U test (two-tailed P t-test and Chi-square test with Yates correction (all two-tailed: P Conclusion We identified theSirt1A2191Gsingle nucleotide polymorphism as a diagnostic marker for VWF.

  2. Enhanced tolerance against early and late apoptotic oxidative stress in mammalian neurons through nicotinamidase and sirtuin mediated pathways.

    Science.gov (United States)

    Chong, Zhao Zhong; Maiese, Kenneth

    2008-08-01

    Focus upon therapeutic strategies that intersect between pathways that govern cellular metabolism and cellular survival may offer the greatest impact for the treatment of a number of neurodegenerative and metabolic disorders, such as diabetes mellitus. In this regard, we investigated the role of a Drosophila nicotinamidase (DN) in mammalian SH-SY5Y neuronal cells during oxidative stress. We demonstrate that during free radical exposure to nitric oxide generators DN neuronal expression significantly increased cell survival and blocked cellular membrane injury. Furthermore, DN neuronal expression prevented both apoptotic late DNA degradation and early phosphatidylserine exposure that may serve to modulate inflammatory cell activation in vivo. Nicotinamidase activity that limited nicotinamide cellular concentrations appeared to be necessary for DN neuroprotection, since application of progressive nicotinamide concentrations could abrogate the benefits of DN expression during oxidative stress. Pathways that involved sirtuin activation and SIRT1 were suggested to be vital, at least in part, for DN to confer protection through a series of studies. First, application of resveratrol increased cell survival during oxidative stress either alone or in conjunction with the expression of DN to a similar degree, suggesting that DN may rely upon SIRT1 activation to foster neuronal protection. Second, the overexpression of either SIRT1 or DN in neurons prevented apoptotic injury specifically in neurons expressing these proteins during oxidative stress, advancing the premise that DN and SIRT1 may employ similar pathways for neuronal protection. Third, inhibition of sirtuin activity with sirtinol was detrimental to neuronal survival during oxidative stress and prevented neuronal protection during overexpression of DN or SIRT1, further supporting that SIRT1 activity may be necessary for DN neuroprotection during oxidative stress. Implementation of further work to elucidate the

  3. miR-217 regulates ethanol-induced hepatic inflammation by disrupting sirtuin 1-lipin-1 signaling.

    Science.gov (United States)

    Yin, Huquan; Liang, Xiaomei; Jogasuria, Alvin; Davidson, Nicholas O; You, Min

    2015-05-01

    Ethanol-mediated injury, combined with gut-derived lipopolysaccharide (LPS), provokes generation of proinflammatory cytokines in Kupffer cells, causing hepatic inflammation. Among the mediators of these effects, miR-217 aggravates ethanol-induced steatosis in hepatocytes. However, the role of miR-217 in ethanol-induced liver inflammation process is unknown. Here, we examined the role of miR-217 in the responses to ethanol, LPS, or a combination of ethanol and LPS in RAW 264.7 macrophages and in primary Kupffer cells. In macrophages, ethanol substantially exacerbated LPS-mediated induction of miR-217 and production of proinflammatory cytokines compared with LPS or ethanol alone. Consistently, ethanol administration to mice led to increases in miR-217 abundance and increased production of inflammatory cytokines in isolated primary Kupffer cells exposed to the combination of ethanol and LPS. miR-217 promoted combined ethanol and LPS-mediated inhibition of sirtuin 1 expression and activity in macrophages. Moreover, miR-217-mediated sirtuin 1 inhibition was accompanied by increased activities of two vital inflammatory regulators, NF-κB and the nuclear factor of activated T cells c4. Finally, adenovirus-mediated overexpression of miR-217 led to steatosis and inflammation in mice. These findings suggest that miR-217 is a pivotal regulator involved in ethanol-induced hepatic inflammation. Strategies to inhibit hepatic miR-217 could be a viable approach in attenuating alcoholic hepatitis. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  4. Design, synthesis and antiviral evaluation of novel heteroarylcarbothioamide derivatives as dual inhibitors of HIV-1 reverse transcriptase-associated RNase H and RDDP functions.

    Science.gov (United States)

    Corona, Angela; Onnis, Valentina; Deplano, Alessandro; Bianco, Giulia; Demurtas, Monica; Distinto, Simona; Cheng, Yung-Chi; Alcaro, Stefano; Esposito, Francesca; Tramontano, Enzo

    2017-08-31

    In the continuous effort to identify new HIV-1 inhibitors endowed with innovative mechanisms, the dual inhibition of different viral functions would provide a significant advantage against drug-resistant variants. The HIV-1 reverse transcriptase (RT)-associated ribonuclease H (RNase H) is the only viral-encoded enzymatic activity that still lacks an efficient inhibitor. We synthesized a library of 3,5-diamino-N-aryl-1H-pyrazole-4-carbothioamide and 4-amino-5-benzoyl-N-phenyl-2-(substituted-amino)-1H-pyrrole-3-carbothioamide derivatives and tested them against RNase H activity. We identified the pyrazolecarbothioamide derivative A15, able to inhibit viral replication and both RNase H and RNA-dependent DNA polymerase (RDDP) RT-associated activities in the low micromolar range. Docking simulations hypothesized its binding to two RT pockets. Site-directed mutagenesis experiments showed that, with respect to wt RT, V108A substitution strongly reduced A15 IC50 values (12.6-fold for RNase H inhibition and 4.7-fold for RDDP), while substitution A502F caused a 9.0-fold increase in its IC50 value for RNase H, not affecting the RDDP inhibition, reinforcing the hypothesis of a dual-site inhibition. Moreover, A15 retained good inhibition potency against three non-nucleoside RT inhibitor (NNRTI)-resistant enzymes, confirming a mode of action unrelated to NNRTIs and suggesting its potential as a lead compound for development of new HIV-1 RT dual inhibitors active against drug-resistant viruses. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Design and Synthesis of Bis-amide and Hydrazide-containing Derivatives of Malonic Acid as Potential HIV-1 Integrase Inhibitors

    Directory of Open Access Journals (Sweden)

    Nouri Neamati

    2008-10-01

    Full Text Available HIV-1 integrase (IN is an attractive and validated target for the development of novel therapeutics against AIDS. In the search for new IN inhibitors, we designed and synthesized three series of bis-amide and hydrazide-containing derivatives of malonic acid. We performed a docking study to investigate the potential interactions of the title compounds with essential amino acids on the IN active site.

  6. Synthesis of Novel N-Branched Acyclic Nucleoside Phosphonates As Potent and Selective Inhibitors of Human, Plasmodium falciparum and Plasmodium vivax 6-Oxopurine Phosphoribosyltransferases

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Keough, D. T.; Janeba, Zlatko; Wang, T.; de Jersey, J.; Guddat, L. W.

    2012-01-01

    Roč. 55, č. 13 (2012), s. 6209-6223 ISSN 0022-2623 R&D Projects: GA ČR GAP207/11/0108; GA MŠk 1M0508 Grant - others:NHMRC(AU) 569703; NHMRC(AU) 1030353 Institutional support: RVO:61388963 Keywords : enzyme inhibitors * aza-ANPs * malaria Subject RIV: CC - Organic Chemistry Impact factor: 5.614, year: 2012

  7. Design, synthesis and docking studies of novel dipeptidyl boronic acid proteasome inhibitors constructed from αα- and αβ-amino acids.

    Science.gov (United States)

    Shi, Jingmiao; Lei, Meng; Wu, Wenkui; Feng, Huayun; Wang, Jia; Chen, Shanshan; Zhu, Yongqiang; Hu, Shihe; Liu, Zhaogang; Jiang, Cheng

    2016-04-15

    A series of novel dipeptidyl boronic acid proteasome inhibitors constructed from αα- and αβ-amino acids were designed and synthesized. Their structures were elucidated by (1)H NMR, (13)C NMR, LC-MS and HRMS. These compounds were evaluated for their β5 subunit inhibitory activities of human proteasome. The results showed that dipeptidyl boronic acid inhibitors composed of αα-amino acids were as active as bortezomib. Interestingly, the activities of those derived from αβ-amino acids lost completely. Of all the inhibitors, compound 22 (IC50=4.82 nM) was the most potent for the inhibition of proteasome activity. Compound 22 was also the most active against three MM cell lines with IC50 values less than 5 nM in inhibiting cell growth assays. Molecular docking studies displayed that 22 fitted very well in the β5 subunit active pocket of proteasome. Copyright © 2016. Published by Elsevier Ltd.

  8. Multipotent cholinesterase/monoamine oxidase inhibitors for the treatment of Alzheimer’s disease: design, synthesis, biochemical evaluation, ADMET, molecular modeling, and QSAR analysis of novel donepezil-pyridyl hybrids

    Directory of Open Access Journals (Sweden)

    Bautista-Aguilera OM

    2014-10-01

    Full Text Available Oscar M Bautista-Aguilera,1,* Gerard Esteban,2,* Mourad Chioua,1 Katarina Nikolic,3 Danica Agbaba,3 Ignacio Moraleda,4 Isabel Iriepa,4 Elena Soriano,5 Abdelouahid Samadi,1 Mercedes Unzeta,2 José Marco-Contelles1 1Laboratory of Medicinal Chemistry (Institute of General Organic Chemistry [IQOG], National Research Council [CSIC], Madrid, Spain; 2Department of Biochemistry and Molecular Biology, Institute of Neurosciences, Autonomous Barcelona University, Barcelona, Spain; 3Institute of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia; 4Department of Organic Chemistry, Faculty of Pharmacy, University of Alcalá, Ctra Barcelona, Alcalá de Henares, Spain; 5Synthesis, and Structure of Organic Compounds (SEPCO (IQOG, CSIC, Madrid, Spain *These authors have equally contributed to this work Abstract: The design, synthesis, and biochemical evaluation of donepezil-pyridyl hybrids (DPHs as multipotent cholinesterase (ChE and monoamine oxidase (MAO inhibitors for the potential treatment of Alzheimer’s disease (AD is reported. The 3D-quantitative structure-activity relationship study was used to define 3D-pharmacophores for inhibition of MAO A/B, acetylcholinesterase (AChE, and butyrylcholinesterase (BuChE enzymes and to design DPHs as novel multi-target drug candidates with potential impact in the therapy of AD. DPH14 (­Electrophorus electricus AChE [EeAChE]: half maximal inhibitory concentration [IC50] =1.1±0.3 nM; equine butyrylcholinesterase [eqBuChE]: IC50 =600±80 nM was 318-fold more potent for the inhibition of AChE, and 1.3-fold less potent for the inhibition of BuChE than the reference compound ASS234. DPH14 is a potent human recombinant BuChE (hBuChE inhibitor, in the same range as DPH12 or DPH16, but 13.1-fold less potent than DPH15 for the inhibition of human recombinant AChE (hAChE. Compared with donepezil, DPH14 is almost equipotent for the inhibition of hAChE, and 8.8-fold more potent for h

  9. Synthesis and Evaluation of Poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene/Magnetite Nanoparticle Composites as Corrosion Inhibitors for Steel

    Directory of Open Access Journals (Sweden)

    Gamal A. El-Mahdy

    2014-01-01

    Full Text Available Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene/magnetite (PAMPS-Na-co-St/Fe3O4 were prepared by emulsifier-free miniemulsion polymerization using styrene (St as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na as an ionic comonomer, N,N-methylenebisacrylamide (MBA as crosslinker, hexadecane (HD as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM. The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA. The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

  10. Design, Synthesis, and Crystal Structures of 6-Alkylidene-2 -Substituted Penicillanic Acid Sulfones as Potent Inhibitors of Acinetobacter baumannii OXA-24 Carbapenemase

    Energy Technology Data Exchange (ETDEWEB)

    Bou, G.; Santillana, E; Sheri, A; Beceiro, A; Sampson, J; Kalp, M; Bethel, C; Distler, A; Drawz, S; et. al.

    2010-01-01

    Class D {beta}-lactamases represent a growing and diverse class of penicillin-inactivating enzymes that are usually resistant to commercial {beta}-lactamase inhibitors. As many such enzymes are found in multi-drug resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa, novel {beta}-lactamase inhibitors are urgently needed. Five unique 6-alkylidene-2{prime}-substituted penicillanic acid sulfones (1-5) were synthesized and tested against OXA-24, a clinically important {beta}-lactamase that inactivates carbapenems and is found in A. baumannii. Based upon the roles Tyr112 and Met223 play in the OXA-24 {beta}-lactamase, we also engineered two variants (Tyr112Ala and Tyr112Ala,Met223Ala) to test the hypothesis that the hydrophobic tunnel formed by these residues influences inhibitor recognition. IC{sub 50} values against OXA-24 and two OXA-24 {beta}-lactamase variants ranged from 10 {+-} 1 (4 vs WT) to 338 {+-} 20 nM (5 vs Tyr112Ala, Met223Ala). Compound 4 possessed the lowest K{sub i} (500 {+-} 80 nM vs WT), and 1 possessed the highest inactivation efficiency (k{sub inact}/K{sub i} = 0.21 {+-} 0.02 {micro}M{sup -1}s{sup -1}). Electrospray ionization mass spectrometry revealed a single covalent adduct, suggesting the formation of an acyl-enzyme intermediate. X-ray structures of OXA-24 complexed to four inhibitors (2.0-2.6 {angstrom}) reveal the formation of stable bicyclic aromatic intermediates with their carbonyl oxygen in the oxyanion hole. These data provide the first structural evidence that 6-alkylidene-2{prime}-substituted penicillin sulfones are effective mechanism-based inactivators of class D {beta}-lactamases. Their unique chemistry makes them developmental candidates. Mechanisms for class D hydrolysis and inhibition are discussed, and a pathway for the evolution of the BlaR1 sensor of Staphylococcus aureus to the class D {beta}-lactamases is proposed.

  11. Design, synthesis, biological evaluation and docking study of 5-oxo-4,5-dihydropyrano[3,2-c]chromene derivatives as acetylcholinesterase and butyrylcholinesterase inhibitors.

    Science.gov (United States)

    Khoobi, Mehdi; Alipour, Masoumeh; Sakhteman, Amirhossein; Nadri, Hamid; Moradi, Alireza; Ghandi, Mehdi; Emami, Saeed; Foroumadi, Alireza; Shafiee, Abbas

    2013-10-01

    A series of fused coumarins namely 5-oxo-4,5-dihydropyrano[3,2-c]chromenes linked to N-benzylpyridinium scaffold were synthesized and evaluated as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. The 1-(4-fluorobenzyl)pyridinium derivative 6g showed the most potent anti-AChE activity (IC50 value=0.038 μM) and the highest AChE/BuChE selectivity (SI>48). The docking study permitted us to rationalize the observed structure-affinity relationships and to detect possible binding modes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  12. Microwave-assisted synthesis of N-pyrazole ureas and the p38alpha inhibitor BIRB 796 for study into accelerated cell ageing.

    Science.gov (United States)

    Bagley, Mark C; Davis, Terence; Dix, Matthew C; Widdowson, Caroline S; Kipling, David

    2006-11-21

    Microwave irradiation of substituted hydrazines and beta-ketoesters gives 5-aminopyrazoles in excellent yield, which can be transformed to the corresponding N-carbonyl derivatives by treatment with an isocyanate or chloroformate. Derivatization of 4-nitronaphth-1-ol using predominantly microwave heating methods and reaction with an N-pyrazole carbamate provides a rapid route to the N-pyrazole urea BIRB 796 in high purity, as a potent and selective inhibitor of p38alpha mitogen-activated protein kinase for the study of accelerated ageing in Werner syndrome cells.

  13. Amide-based inhibitors of p38alpha MAP kinase. Part 2: design, synthesis and SAR of potent N-pyrimidyl amides.

    Science.gov (United States)

    Tester, Richland; Tan, Xuefei; Luedtke, Gregory R; Nashashibi, Imad; Schinzel, Kurt; Liang, Weiling; Jung, Joon; Dugar, Sundeep; Liclican, Albert; Tabora, Jocelyn; Levy, Daniel E; Do, Steven

    2010-04-15

    Optimization of a tri-substituted N-pyridyl amide led to the discovery of a new class of potent N-pyrimidyl amide based p38alpha MAP kinase inhibitors. Initial SAR studies led to the identification of 5-dihydrofuran as an optimal hydrophobic group. Additional side chain modifications resulted in the introduction of hydrogen bond interactions. Through extensive SAR studies, analogs bearing free amino groups and alternatives to the parent (S)-alpha-methyl benzyl moiety were identified. These compounds exhibited improved cellular activities and maintained balance between p38alpha and CYP3A4 inhibition. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Design and Synthesis of Novel N-Benzylidenesulfonohydrazide Inhibitors of MurC and MurD as Potential Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Aleš Obreza

    2008-01-01

    Full Text Available A series of novel N-benzylidenesulfonohydrazide compounds were designedand synthesized as inhibitors of UDP-N-acetylmuramic acid:L-alanine ligase (MurC andUDP-N-acetylmuramoyl-L-alanine:D-glutamate ligase (MurD from E. coli, involved inthe biosynthesis of bacterial cell-walls. Some compounds possessed inhibitory activityagainst both enzymes with IC50 values as low as 30 μM. In addition, a new, one-potsynthesis of amidobenzaldehydes is reported.

  15. Synthesis and SAR of 1-acetanilide-4-aminopyrazole-substituted quinazolines: selective inhibitors of Aurora B kinase with potent anti-tumor activity.

    Science.gov (United States)

    Foote, Kevin M; Mortlock, Andrew A; Heron, Nicola M; Jung, Frédéric H; Hill, George B; Pasquet, Georges; Brady, Madeleine C; Green, Stephen; Heaton, Simon P; Kearney, Sarah; Keen, Nicholas J; Odedra, Rajesh; Wedge, Stephen R; Wilkinson, Robert W

    2008-03-15

    A new class of 1-acetanilide-4-aminopyrazole-substituted quinazoline Aurora kinase inhibitors has been discovered possessing highly potent cellular activity. Continuous infusion into athymic mice bearing SW620 tumors of the soluble phosphate derivative 2 led to dose-proportional exposure of the des-phosphate compound 8 with a high-unbound fraction. The combination of potent cell activity and high free-drug exposure led to pharmacodynamic changes in the tumor at low doses, indicative of Aurora B-kinase inhibition and a reduction in tumor volume.

  16. Synthesis and Evaluation of Bicyclo[3.1.0]hexane-Based UDP-Galf Analogues as Inhibitors of the Mycobacterial Galactofuranosyltransferase GlfT2

    Directory of Open Access Journals (Sweden)

    Todd L. Lowary

    2016-08-01

    Full Text Available UDP-galactofuranose (UDP-Galf is the donor substrate for both bifunctional galactofuranosyltransferases, GlfT1 and GlfT2, which are involved in the biosynthesis of mycobacterial galactan. In this paper, a group of UDP-Galf mimics were synthesized via reductive amination of a bicyclo[3.1.0]hexane-based amine by reacting with aromatic, linear, or uridine-containing aldehydes. These compounds were evaluated against GlfT2 using a coupled spectrophotometric assay, and were shown to be weak inhibitors of the enzyme.

  17. Design, chemical synthesis and kinetic studies of trypsin chromogenic substrates based on the proteinase binding loop of Cucurbita maxima trypsin inhibitor (CMTI-III).

    Science.gov (United States)

    Lesner, A; Brzozowski, K; Kupryszewski, G; Rolka, K

    2000-03-05

    A series of trypsin chromogenic substrates with formula: Y-Ala-X-Abu-Pro-Lys-pNA, where X = Gly, Ala, Abu, Val, Leu, Phe, Ser, Glu and Y = Ac, H; pNA = p-nitroanilide was synthesized. The Cucurbita maxima trypsin inhibitor CMTI-III molecule was used as a vehicle to design the trypsin substrates. To evaluate the influence of position P(4) on the substrate-enzyme interaction, kinetic parameters of newly synthesized substrates with bovine beta-trypsin were determined. The increasing hydrophobicity of the amino acid residue (Gly, Ala, Abu, Val) introduced in position P(4) significantly enhanced the substrate specificity (k(cat)/K(m)) which was over 8 times higher for the last residue than that for the first one. The introduction of residues with more hydrophilic side chain (Glu, Ser) in this position reduced the value of this parameter. These results correspond well with those obtained using molecular dynamics of bovine beta-trypsin with monosubstituted CMTI-I analogues, indicating that in both trypsin substrate and inhibitor position 4 plays an important role in the interaction with the enzyme. Copyright 2000 Academic Press.

  18. Design, Synthesis, and Pharmacological Evaluation of Novel Multisubstituted Pyridin-3-amine Derivatives as Multitargeted Protein Kinase Inhibitors for the Treatment of Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Zhu, Wei; Chen, Hui; Wang, Yulan; Wang, Jiang; Peng, Xia; Chen, Xianjie; Gao, Yinglei; Li, Chunpu; He, Yulong; Ai, Jing; Geng, Meiyu; Zheng, Mingyue; Liu, Hong

    2017-07-27

    A novel series of pyridin-3-amine derivatives were designed, synthesized, and evaluated as multitargeted protein kinase inhibitors for the treatment of non-small cell lung cancer (NSCLC). Hit 1 was first disclosed by in silico screening against fibroblast growth factor receptors (FGFR), which was subsequently validated by in vitro experiments. The structure-activity relationship (SAR) of its analogues was then explored to afford novel FGFR inhibitors 2a-2p and 3a-3q. Among them, 3m showed potent inhibition against FGFR1, 2, and 3. Interestingly, compound 3m not only inhibited various phosphorylation and downstream signaling across different oncogenic forms in FGFR-overactivated cancer cells but also showed nanomolar level inhibition against several other NSCLC-related oncogene kinases, including RET, EGFR, EGFR/T790M/L858R, DDR2, and ALK. Finally, in vivo pharmacology evaluations of 3m showed significant antitumor activity (TGI = 66.1%) in NCI-H1581 NSCLC xenografts with a good pharmacokinetic profile.

  19. Synthesis, biological evaluation and molecular docking of novel 5-phenyl-1H-pyrazol derivatives as potential BRAF(V600E) inhibitors.

    Science.gov (United States)

    Dong, Jing-Jun; Li, Qing-Shan; Wang, Shu-Fu; Li, Cui-Yun; Zhao, Xin; Qiu, Han-Yue; Zhao, Meng-Yue; Zhu, Hai-Liang

    2013-10-07

    The RAF-MEK-ERK cascade appears to be intimately involved in the regulation of cell cycle progression and apoptosis. The BRAF(V600E) mutant results in constitutive activation of the ERK pathway, which can lead to cellular growth dysregulation. A series of 5-phenyl-1H-pyrazol derivatives (3a-5e) have been designed and synthesized, and their biological activities were evaluated as potential BRAF(V600E) inhibitors. All the compounds were reported for the first time except 3e, and compound 1-(4-bromo-2-hydroxybenzyl)-3-phenyl-1-(5-phenyl-1H-pyrazol-3-yl)urea (5c) displayed the most potent inhibitory activity (BRAF(V600E) IC50 = 0.19 μM). Antiproliferative assay results indicated that compound 5c possessed high antiproliferative activity against cell lines WM266.4 and A375 in vitro, with IC50 values of 1.50 and 1.32 μM, respectively, which were comparable with the positive control vemurafenib. Docking simulations showed that compound 5c binds tightly to the BRAF(V600E) active site and acts as BRAF(V600E) inhibitor. A 3D-QSAR model was also built to provide more pharmacophore understanding towards designing new agents with more potent BRAF(V600E) inhibitory activity.

  20. Design, Synthesis, and Biological Evaluation of Some Novel Pyrrolizine Derivatives as COX Inhibitors with Anti-Inflammatory/Analgesic Activities and Low Ulcerogenic Liability

    Directory of Open Access Journals (Sweden)

    Ahmed M. Gouda

    2016-02-01

    Full Text Available Non-steroidal anti-inflammatory drugs (NSAIDs are the most commonly prescribed anti-inflammatory and pain relief medications. However, their use is associated with many drawbacks, including mainly serious gastric and renal complications. In an attempt to circumvent these risks, a set of N-(4-bromophenyl-7-cyano-6-substituted-H-pyrrolizine-5-carboxamide derivatives were designed, synthesized and evaluated as dual COX/5-LOX inhibitors. The structural elucidation, in vivo anti-inflammatory and analgesic activities using a carrageenan-induced rat paw edema model and hot plate assay, were performed, respectively. From the results obtained, it was found that the newly synthesized pyrrolizines exhibited IC50 values in the range of 2.45–5.69 µM and 0.85–3.44 µM for COX-1 and COX-2, respectively. Interestingly, compounds 12, 13, 16 and 17 showed higher anti-inflammatory and analgesic activities compared to ibuprofen. Among these derivatives, compounds 16 and 19 displayed better safety profile than ibuprofen in acute ulcerogenicity and histopathological studies. Furthermore, the docking studies revealed that compound 17 fits nicely into COX-1 and COX-2 binding sites with the highest binding affinity, while compound 16 exerted the highest binding affinity for 5-LOX. In light of these findings, these novel pyrrolizine-5-carboxamide derivatives represent a promising scaffold for further development into potential dual COX/5-LOX inhibitors with safer gastric profile.

  1. Structure-based design, synthesis, and biological evaluation of novel pyrrolyl aryl sulfones: HIV-1 non-nucleoside reverse transcriptase inhibitors active at nanomolar concentrations.

    Science.gov (United States)

    Artico, M; Silvestri, R; Pagnozzi, E; Bruno, B; Novellino, E; Greco, G; Massa, S; Ettorre, A; Loi, A G; Scintu, F; La Colla, P

    2000-05-04

    Pyrrolyl aryl sulfones (PASs) have been recently reported as a new class of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) inhibitors acting at the non-nucleoside binding site of this enzyme (Artico, M.; et al. J. Med. Chem. 1996, 39, 522-530). Compound 3, the most potent inhibitor within the series (EC(50) = 0.14 microM, IC(50) = 0.4 microM, and SI > 1429), was then selected as a lead compound for a synthetic project based on molecular modeling studies. Using the three-dimensional structure of RT cocrystallized with the alpha-APA derivative R95845, we derived a model of the RT/3 complex by taking into account previously developed structure-activity relationships. Inspection of this model and docking calculations on virtual compounds prompted the design of novel PAS derivatives and related analogues. Our computational approach proved to be effective in making qualitative predictions, that is in discriminating active versus inactive compounds. Among the compounds synthesized and tested, 20 was the most active one, with EC(50) = 0.045 microM, IC(50) = 0.05 microM, and SI = 5333. Compared with the lead 3, these values represent a 3- and 8-fold improvement in the cell-based and enzyme assays, respectively, together with the highest selectivity achieved so far in the PAS series.

  2. Design, synthesis and biological activity of novel donepezil derivatives bearing N-benzyl pyridinium moiety as potent and dual binding site acetylcholinesterase inhibitors.

    Science.gov (United States)

    Lan, Jin-Shuai; Zhang, Tong; Liu, Yun; Yang, Jing; Xie, Sai-Sai; Liu, Jing; Miao, Ze-Yang; Ding, Yue

    2017-06-16

    A series of new donepezil derivatives were designed synthesized and evaluated as multifunctional cholinesterase inhibitors against Alzheimer's disease (AD). In vitro studies showed that most of them exhibited significant potency to inhibit acetylcholinesterase and self-induced β-amyloid (Aβ) aggregation, and moderate antioxidant activity. Especially, compound 5b presented the greatest ability to inhibit cholinesterase (IC 50 , 1.9 nM for eeAChE and 0.8 nM for hAChE), good inhibition of Aβ aggregation (53.7% at 20 μM) and good antioxidant activity (0.54 trolox equivalents). Kinetic and molecular modeling studies indicated that compound 5b was a mixed-type inhibitor, binding simultaneously to the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. In addition, compound 5b could reduce PC12 cells death induced by oxidative stress and Aβ (1-42). Moreover, in vivo experiments showed that compound 5b was nontoxic and tolerated at doses up to 2000 mg/kg. These results suggested that compound 5b might be an excellent multifunctional agent for AD treatment. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Focused library design and synthesis of 2-mercapto benzothiazole linked 1,2,4-oxadiazoles as COX-2/5-LOX inhibitors

    Science.gov (United States)

    Yatam, Satayanarayana; Gundla, Rambabu; Jadav, Surender Singh; Pedavenkatagari, Narayana reddy; Chimakurthy, Jithendra; Rani B, Namratha; Kedam, Thyagaraju

    2018-05-01

    Mercapto benzothiazole linked 1,2,4-oxadiazole derivatives were designed (4a-u) as new anti-inflammatory agents using bioisosteric approach and docking studies. The docking results clearly indicated that the compounds 4a-u shown good docking interaction towards COX-2 enzyme. In silico drug-like properties were also calculated for compounds (4a-u) and exhibited significant H-bond acceptor ratio. All compounds were synthesized and biologically evaluated using in vitro COX-1, COX-2 and 5-LOX assays. Compound 4k and 4q (IC50 = 6.8 μM and IC50 = 5.0 μM) found to be potent, selective COX-2 inhibitors and display better anti-inflammatory activity than standard Ibuprofen. Compound 4l and 4e found to be potent inhibitors against 5-LOX (IC50 = 5.1 μM and IC50 = 5.5 μM). The in vivo anti-inflammatory activity studies shown that the compounds 4q and 4k effectively reducing the paw edema volume at 3h and 5h than standard drug Ibuprofen. The DPPH radical scavenging activity provided anti-oxidant activity of compound 4e (IC50 = 25.6 μM) than reference standard Ascorbic acid.

  4. Potent Inhibitors of the Hepatitis C Virus NS3 Protease: Design and Synthesis of Macrocyclic Substrate-Based [beta]-Strand Mimics

    Energy Technology Data Exchange (ETDEWEB)

    Goudreau, Nathalie; Brochu, Christian; Cameron, Dale R.; Duceppe, Jean-Simon; Faucher, Anne-Marie; Ferland, Jean-Marie; Grand-Maître, Chantal; Poirier, Martin; Simoneau, Bruno; Tsantrizos, Youla S. (Boehringer)

    2008-06-30

    The virally encoded NS3 protease is essential to the life cycle of the hepatitis C virus (HCV), an important human pathogen causing chronic hepatitis, cirrhosis of the liver, and hepatocellular carcinoma. The design and synthesis of 15-membered ring {beta}-strand mimics which are capable of inhibiting the interactions between the HCV NS3 protease enzyme and its polyprotein substrate will be described. The binding interactions between a macrocyclic ligand and the enzyme were explored by NMR and molecular dynamics, and a model of the ligand/enzyme complex was developed.

  5. New isochaetochromin, an inhibitor of triacylglycerol synthesis in mammalian cells, produced by Penicillium sp. FKI-4942: I. Taxonomy, fermentation, isolation and biological properties.

    Science.gov (United States)

    Ugaki, Narihiro; Matsuda, Daisuke; Yamazaki, Hiroyuki; Nonaka, Kenichi; Masuma, Rokuro; Omura, Satoshi; Tomoda, Hiroshi

    2012-01-01

    A new bis-naphtho-γ-pyrone isomer named isochaetochromin A(1) was isolated along with known isochaetochromins B(1) and B(2) from the culture broth of Penicillium sp. FKI-4942 by solvent extraction, silica gel column chromatography and HPLC. Among them, isochaetochromin B(1) showed the most potent inhibitory activity of triacylglycerol synthesis with an IC(50) value of 5.6 μM, followed by isochaetochromins B(2) (IC(50), 11 μM) and A(1) (33 μM).

  6. Scheduled and unscheduled DNA synthesis in chick embryo liver following X-irradiation and treatment with DNA repair inhibitors in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Stammberger, I.; Tempel, K. (Muenchen Univ. (Germany, F.R.). Inst. fuer Pharmakologie und Toxikologie); Schmahl, W. (Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg (Germany, F.R.). Inst. fuer Pathologie)

    1989-09-01

    Three hours following X-irradiation of chick embryos with doses of 4 and 8 Gy the in vitro incorporation of tritiated thymidine (({sup 3}H)dT) into DNA (scheduled DNA synthesis, ss) of hepatocytes was reduced to about one-third. Within 24 h after the exposure, ss returned to control values. The return of ss to a normal rate could be strongly inhibited by 2', 3'-dideoxythymidine (ddT), and to a lesser extent by 1-beta-D-arabinofuranosylcytosine (araC). In strong contrast to ss, the hydroxyurea (hu)-resistant ({sup 3)H}dT incorporation (unscheduled DNA synthesis, us) showed a highly significant increase 24 h after treatment of the embryos with araC and/or X-irradiation. Autoradiographic studies revealed no change of total ({sup 3}H)dT labelling frequency in the whole chick embryo liver 24 h after treatment with araC and/or X-irradiation, but a persistent depression of ss and a simultaneous increase of us. (author).

  7. 6-Substituted 3,4-dihydro-naphthalene-2-carboxylic acids: synthesis and structure-activity studies in a novel class of human 5alpha reductase inhibitors.

    Science.gov (United States)

    Baston, Eckhard; Salem, Ola I A; Hartmann, Rolf W

    2002-10-01

    Novel 3,4-dihydro-naphthalene-2-carboxylic acids were synthesized and evaluated for 5alpha reductase inhibitory activity. This enzyme exists in two isoforms and is a pharmacological target for the treatment of benign prostatic hyperplasia, male pattern baldness and acne. In the present study non-steroidal compounds capable of mimicking the transition state of the steroidal substrates were prepared. The synthetic strategy for the preparation of compounds 1-6 consisted of triflation followed by subsequent Heck-type carboxylation or methoxy carbonylation for 6-phenyl-3,4-dihydronaphthalen-2(1H)-one 1c. A Negishi-type coupling reaction between 6-(trifluoro-methanesulfonyloxy)-3,4-dihydro-naphthalene-2-carboxylic acid methyl ester 7b and various aryl bromides led, after further transformations, to 6-substituted 3,4-dihydro-naphthalene-2-carboxylic acids 7-15. In a similar way the corresponding naphthalene-2-carboxylic acids 16 and 17 were obtained. The DU 145 cell line and prostate homogenates served as enzyme sources for the human type 1 and type 2 isozymes, whereas ventral prostate was employed to evaluate rat isozyme inhibitory potency. The most active inhibitors identified in this study were 6-[4-(N,N-dicyclohexylaminocarbonyl)phenyl]-3,4-dihydro-naphthalene-2-carboxylic acid (3) (IC50 = 0.09 microM, rat type 1), 6-[3-(N,N-dicyclohexylaminocarbonyl)phenyl]-3,4-dihydro-naphthalene-2-carboxylic acid (13) (IC50 = 0.75 microM, human type 2; IC50 = 0.81 microM, human type 1) and 6-[4-(N,N-diisopropylamino-carbonyl)phenyl]naphthalene-2-carboxylic acid (16) (IC50 = 0.2 microM, human type 2). The latter compound was shown to deactivate the enzyme in an uncompetitive manner (Ki = 90 nM; Km, Testosterone = 0.8-1.0 microM) similar to the steroidal inhibitor Epristeride. Select inhibitors (13 and 16) were tested in vivo using testosterone propionate-treated, juvenile, orchiectomized SD-rats. None of the compounds was active at a dose of 25 mg/kg. This result might in part be

  8. Structure-based drug design, synthesis and biological assays of P. falciparum Atg3-Atg8 protein-protein interaction inhibitors

    Science.gov (United States)

    Villa, Stefania; Legnani, Laura; Colombo, Diego; Gelain, Arianna; Lammi, Carmen; Bongiorno, Daniele; Ilboudo, Denise P.; McGee, Kellen E.; Bosch, Jürgen; Grazioso, Giovanni

    2018-03-01

    The proteins involved in the autophagy (Atg) pathway have recently been considered promising targets for the development of new antimalarial drugs. In particular, inhibitors of the protein-protein interaction (PPI) between Atg3 and Atg8 of Plasmodium falciparum retarded the blood- and liver-stages of parasite growth. In this paper, we used computational techniques to design a new class of peptidomimetics mimicking the Atg3 interaction motif, which were then synthesized by click-chemistry. Surface plasmon resonance has been employed to measure the ability of these compounds to inhibit the Atg3-Atg8 reciprocal protein-protein interaction. Moreover, P. falciparum growth inhibition in red blood cell cultures was evaluated as well as the cyto-toxicity of the compounds.

  9. Synthesis of (E)-N'-[1-(2,4-Dihydroxyphenyl)ethylidene]substituted hydrazides as possible alpha-glucosidase and butyrylcholinesterase Inhibitors

    International Nuclear Information System (INIS)

    Abbasi, M.A.; Shah, S.A.H.; Siddiqui, S.Z.; Khan, K.M.

    2017-01-01

    In the current research work, (E)-N'-[1-(2,4-dihydroxyphenyl)ethylidene]substituted hydrazides were synthesized in a couple of steps and their enzyme inhibition potential was analyzed. Firstly 2,4-hydroxyacetophenone (1) was reacted with hydrated hydrazine (2) under stirring to yield (E)-4-(1-hydrazonoethyl)benzene-1,3-diol (3) which was further reacted with different acid halides, (4a-i) to afford (E)-[1-(2,4-dihydroxyphenyl)ethylidene]substituted hydrazides (5a-i). These synthesized compounds were characterized by EI-MS, 1H-NMR spectral techniques and were also evaluated against a-glucosidase and butyrylcholinesterase enzymes. The synthesized compounds were found to be acceptable inhibitors of a-glucosidase and decent inhibition against butyrylcholinesterase. (author)

  10. Synthesis and evaluation of small libraries of triazolylmethoxy chalcones, flavanones and 2-aminopyrimidines as inhibitors of mycobacterial FAS-II and PknG.

    Science.gov (United States)

    Anand, Namrata; Singh, Priyanka; Sharma, Anindra; Tiwari, Sameer; Singh, Vandana; Singh, Diwakar K; Srivastava, Kishore K; Singh, B N; Tripathi, Rama Pati

    2012-09-01

    A synthetic strategy to access small libraries of triazolylmethoxy chalcones 4{1-20}, triazolylmethoxy flavanones 5{1-10} and triazolylmethoxy aminopyrimidines 6{1-17} from a common substrate 4-propargyloxy-2-hydroxy acetophenone using a set of different reactions has been developed. The chalcones and flavanones were screened against mycobacterial FAS-II pathway using a recombinant mycobacterial strain, against which the most potent compound showed ∼88% inhibition in bacterial growth and substantially induction of reporter gene activity at 100 μM concentration. The triazolylmethoxy aminopyrimdines were screened against PknG of Mycobaceterium tuberculosis displaying moderate to good activity (23-53% inhibition at 100 μM), comparable to the action of a standard inhibitor. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Design, synthesis and structure-activity relationships of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease.

    Science.gov (United States)

    Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio; Kogen, Hiroshi

    2003-05-01

    We have designed and synthesized a dual inhibitor of acetylcholinesterase (AChE) and serotonin transporter (SERT) as a novel class of treatment drugs for Alzheimer's disease on the basis of a hypothetical model of the AChE active site. Dual inhibitions of AChE and SERT would bring about greater therapeutic effects than AChE inhibition alone and avoid adverse peripheral effects caused by excessive AChE inhibition. Compound (S)-6j exhibited potent inhibitory activities against AChE (IC(50)=101 nM) and SERT (IC(50)=42 nM). Furthermore, (S)-6j showed inhibitory activities of both AChE and SERT in mice brain following oral administration.

  12. Copper(II) complexes of methimazole, an anti Grave's disease drug. Synthesis, characterization and its potential biological behavior as alkaline phosphatase inhibitor.

    Science.gov (United States)

    Urquiza, Nora M; Manca, Silvia G; Moyano, María A; Dellmans, Raquel Arrieta; Lezama, Luis; Rojo, Teófilo; Naso, Luciana G; Williams, Patricia A M; Ferrer, Evelina G

    2010-04-01

    Methimazole (MeimzH) is an anti-thyroid drug and the first choice for patients with Grave's disease. Two new copper(II) complexes of this drug: [Cu(MeimzH)(2)(NO(3))(2)]*0.5H(2)O and [Cu(MeimzH)(2)(H(2)O)(2)](NO(3))(2)*H(2)O were synthesized and characterized by elemental analysis, dissolution behavior, thermogravimetric analysis and UV-vis, diffuse reflectance, FTIR and EPR spectroscopies. As it is known that copper(II) cation can act as an inhibitor of alkaline phosphatase (ALP), the inhibitory effect of methimazole and its copper(II) complexes on ALP activity has also been investigated.

  13. Effects of nitric oxide synthesis inhibitor or fluoxetine treatment on depression-like state and cardiovascular changes induced by chronic variable stress in rats.

    Science.gov (United States)

    Almeida, Jeferson; Duarte, Josiane O; Oliveira, Leandro A; Crestani, Carlos C

    2015-01-01

    Comorbidity between mood disorders and cardiovascular disease has been described extensively. However, available antidepressants can have cardiovascular side effects. Treatment with selective inhibitors of neuronal nitric oxide synthase (nNOS) induces antidepressant effects, but whether the antidepressant-like effects of these drugs are followed by cardiovascular changes has not been previously investigated. Here, we tested in male rats exposed to chronic variable stress (CVS) the hypothesis that nNOS blockers are advantageous compared with conventional antidepressants in terms of cardiovascular side effects. We compared the effects of chronic treatment with the preferential nNOS inhibitor 7-nitroindazole (7-NI) with those evoked by the conventional antidepressant fluoxetine on alterations that are considered as markers of depression (immobility in the forced swimming test, FST, decreased body weight gain and increased plasma corticosterone concentration) and cardiovascular changes caused by CVS. Rats were exposed to a 14-day CVS protocol, while being concurrently treated daily with either 7-NI (30 mg/kg) or fluoxetine (10 mg/kg). Fluoxetine and 7-NI prevented the increase in immobility in the FST induced by CVS and reduced plasma corticosterone concentration in stressed rats. Both these treatments also prevented the CVS-evoked reduction of the depressor response to vasodilator agents and baroreflex changes. Fluoxetine and 7-NI-induced cardiovascular changes independent of stress exposure, including cardiac autonomic imbalance, increased intrinsic heart rate and vascular sympathetic modulation, a reduction of the pressor response to vasoconstrictor agents, and impairment of baroreflex activity. Altogether, these findings provide evidence that fluoxetine and 7-NI have similar effects on the depression-like state induced by CVS and on cardiovascular function.

  14. Sirtuin 7 promotes cellular survival following genomic stress by attenuation of DNA damage, SAPK activation and p53 response

    Energy Technology Data Exchange (ETDEWEB)

    Kiran, Shashi; Oddi, Vineesha [Laboratory of Cancer Biology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, 500001 (India); Ramakrishna, Gayatri, E-mail: gayatrirama1@gmail.com [Laboratory of Cancer Biology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, 500001 (India); Laboratory of Cancer Cell Biology, Department of Research, Institute of Liver and Biliary Sciences, Delhi 110070 (India)

    2015-02-01

    Maintaining the genomic integrity is a constant challenge in proliferating cells. Amongst various proteins involved in this process, Sirtuins play a key role in DNA damage repair mechanisms in yeast as well as mammals. In the present work we report the role of one of the least explored Sirtuin viz., SIRT7, under conditions of genomic stress when treated with doxorubicin. Knockdown of SIRT7 sensitized osteosarcoma (U2OS) cells to DNA damage induced cell death by doxorubicin. SIRT7 overexpression in NIH3T3 delayed cell cycle progression by causing delay in G1 to S transition. SIRT7 overexpressing cells when treated with low dose of doxorubicin (0.25 µM) showed delayed onset of senescence, lesser accumulation of DNA damage marker γH2AX and lowered levels of growth arrest markers viz., p53 and p21 when compared to doxorubicin treated control GFP expressing cells. Resistance to DNA damage following SIRT7 overexpression was also evident by EdU incorporation studies where cellular growth arrest was significantly delayed. When treated with higher dose of doxorubicin (>1 µM), SIRT7 conferred resistance to apoptosis by attenuating stress activated kinases (SAPK viz., p38 and JNK) and p53 response thereby shifting the cellular fate towards senescence. Interestingly, relocalization of SIRT7 from nucleolus to nucleoplasm together with its co-localization with SAPK was an important feature associated with DNA damage. SIRT7 mediated resistance to doxorubicin induced apoptosis and senescence was lost when p53 level was restored by nutlin treatment. Overall, we propose SIRT7 attenuates DNA damage, SAPK activation and p53 response thereby promoting cellular survival under conditions of genomic stress. - Highlights: • Knockdown of SIRT7 sensitized cells to DNA damage induced apoptosis. • SIRT7 delayed onset of premature senescence by attenuating DNA damage response. • Overexpression of SIRT7 delayed cell cycle progression by delaying G1/S transition. • Upon DNA damage SIRT

  15. Ligand-based virtual screening and inductive learning for identification of SIRT1 inhibitors in natural products.

    Science.gov (United States)

    Sun, Yunan; Zhou, Hui; Zhu, Hongmei; Leung, Siu-wai

    2016-01-25

    Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide-dependent deacetylase, and its dysregulation can lead to ageing, diabetes, and cancer. From 346 experimentally confirmed SIRT1 inhibitors, an inhibitor structure pattern was generated by inductive logic programming (ILP) with DMax Chemistry Assistant software. The pattern contained amide, amine, and hetero-aromatic five-membered rings, each of which had a hetero-atom and an unsubstituted atom at a distance of 2. According to this pattern, a ligand-based virtual screening of 1 444 880 active compounds from Chinese herbs identified 12 compounds as inhibitors of SIRT1. Three compounds (ZINC08790006, ZINC08792229, and ZINC08792355) had high affinity (-7.3, -7.8, and -8.6 kcal/mol, respectively) for SIRT1 as estimated by molecular docking software AutoDock Vina. This study demonstrated a use of ILP and background knowledge in machine learning to facilitate virtual screening.

  16. Myocardial repair with long-term and low-dose administration of a nitric oxide synthesis inhibitor. Myofibroblasts, type III collagen and fibronectin

    Directory of Open Access Journals (Sweden)

    Pessanha Mônica Gomes

    1999-01-01

    Full Text Available OBJECTIVE: To study the healing process of the myocardium in hypertensive rats undergoing inhibition of nitric oxide synthesis. METHODS: Two groups of animals were studied: one received L-NAME, 12mg/kg/day, and the other was a control group. The presence of type III collagen, fibronectin, and alpha-smooth muscle actin-positive cells was assessed by immunohistochemistry. RESULTS: Fibronectin was seen in both early and late lesions, while type III collagen was seen mainly in areas of incomplete healing, situated among myocytes and around the intramyocardial branches of the coronary arteries. Areas representing early and late lesions showed a population of spindle-shaped cells. Immunohistochemistry showed that these cells were positive for alpha-smooth muscle actin. CONCLUSION: In the myocardium of hypertensive rats, the alpha-smooth muscle actin-positive cells are related to the accumulation of type III collagen and fibronectin in the areas of myocardial damage.

  17. Influence of Polyphenol Extract from Evening Primrose (Oenothera Paradoxa Seeds on Proliferation of Caco-2 Cells and on Expression, Synthesis and Activity of Matrix Metalloproteinases and Their Inhibitors

    Directory of Open Access Journals (Sweden)

    Szewczyk Karolina

    2014-09-01

    Full Text Available Evening primrose (Oenothera paradoxa Hudziok seeds are a rich source of not only a valuable oil containing an essential fatty acid - ᵧ-linolenic acid (GLA - but also polyphenols which can be obtained from the biomass remaining after oil pressing. The aim of our studies was to evaluate the influence of a polyphenol extract from defatted seeds of evening primrose on human colorectal adenocarcinoma Caco-2 cell proliferation and matrix metalloproteinases (MMPs synthesis and activity. To assess the effect of evening primrose extract on Caco-2 cell proliferation, crystal violet staining and sulforhodamine B (SRB assays were used whereas mRNA expression and activity of MMPs were evaluated by RT-PCR and gelatin zymography.

  18. Prolactin is a major inhibitor of hepatic Leptin A synthesis and secretion: studies utilizing a homologous Leptin A ELISA in the tilapia.

    Science.gov (United States)

    Douros, Jonathan D; Baltzegar, David A; Breves, Jason P; Lerner, Darren T; Seale, Andre P; Gordon Grau, E; Borski, Russell J

    2014-10-01

    The present study identifies regulatory interactions between leptin A (LepA) and the pituitary hormone prolactin (PRL). In order to measure tilapia (Oreochromis mossambicus) LepA, an enzyme-linked immunosorbent assay (ELISA) utilizing a rabbit polyclonal antibody specific to tilapia LepA was first developed. The antibody shows strong cross reactivity to recombinant tilapia LepA (rtLepA), and a corresponding 16kDa protein in both tilapia and striped bass plasma, but not to recombinant human leptin (rhLep). The assay has a linear detection range of 0.25-1000nM, with intra- and interassay variability of 9% and 16%, respectively. Plasma LepA levels measured in tilapia ranged from 0.8 to 3.9nM, similar to that found for other vertebrates. Hypophysectomy (Hx) increased circulating LepA and lepa mRNA levels in the liver, the dominant source of hormone production. Adminstration of ovine PRL (oPRL, 5μg/g BW) to Hx fish restored circulating LepA and hepatic lepa mRNA levels to those of control fish. Additionally, oPRL reduced lepa mRNA levels in a dose-dependent fashion in cultured hepatocytes following an 18h incubation. Previous work in our lab indicates that rhLep stimulates PRL release in vitro from tilapia pituitaries. Here, both rtLepA and rhLep (0.5μg/g BW) increased mRNA expression of tilapia prolactin mRNAs (prl1, prl2) in the pituitary in vivo. These results demonstrate that LepA enhances pituitary prolactin synthesis and release, while PRL in turn inhibits hepatic leptin secretion and synthesis in teleosts. We postulate this regulatory interaction may be necessary for mobilizing energy reserves during acute hyperosmotic adaptation. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Design, synthesis, pharmacological evaluation, QSAR analysis, molecular modeling and ADMET of novel donepezil-indolyl hybrids as multipotent cholinesterase/monoamine oxidase inhibitors for the potential treatment of Alzheimer's disease.

    Science.gov (United States)

    Bautista-Aguilera, Oscar M; Esteban, Gerard; Bolea, Irene; Nikolic, Katarina; Agbaba, Danica; Moraleda, Ignacio; Iriepa, Isabel; Samadi, Abdelouahid; Soriano, Elena; Unzeta, Mercedes; Marco-Contelles, José

    2014-03-21

    The design, synthesis, and pharmacological evaluation of donepezil-indolyl based amines 7-10, amides 12-16, and carboxylic acid derivatives 5 and 11, as multipotent ASS234 analogs, able to inhibit simultaneously cholinesterase (ChE) and monoamine oxidase (MAO) enzymes for the potential treatment of Alzheimer's disease (AD), is reported. Theoretical studies using 3D-Quantitative Structure-Activity Relationship (3D-QSAR) was used to define 3D-pharmacophores for inhibition of MAO A/B, AChE, and BuChE enzymes. We found that, in general, and for the same substituent, amines are more potent ChE inhibitors (see compounds 12, 13 versus 7 and 8) or equipotent (see compounds 14, 15 versus 9 and 10) than the corresponding amides, showing a clear EeAChE inhibition selectivity. For the MAO inhibition, amides were not active, and among the amines, compound 14 was totally MAO A selective, while amines 15 and 16 were quite MAO A selective. Carboxylic acid derivatives 5 and 11 showed a multipotent moderate selective profile as EeACE and MAO A inhibitors. Propargylamine 15 [N-((5-(3-(1-benzylpiperidin-4-yl)propoxy)-1-methyl-1H-indol-2-yl)methyl)prop-2-yn-1-amine] resulted in the most potent hMAO A (IC50 = 5.5 ± 1.4 nM) and moderately potent hMAO B (IC50 = 150 ± 31 nM), EeAChE (IC50 = 190 ± 10 nM), and eqBuChE (IC50 = 830 ± 160 nM) inhibitor. However, the analogous N-allyl and the N-morpholine derivatives 16 and 14 deserve also attention as they show an attractive multipotent profile. To sum up, donepezil-indolyl hybrid 15 is a promising drug for further development for the potential prevention and treatment of AD. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Melatonin reverses H2 O2 -induced senescence in SH-SY5Y cells by enhancing autophagy via sirtuin 1 deacetylation of the RelA/p65 subunit of NF-κB.

    Science.gov (United States)

    Nopparat, Chutikorn; Sinjanakhom, Puritat; Govitrapong, Piyarat

    2017-08-01

    Autophagy, a degradation mechanism that plays a major role in maintaining cellular homeostasis and diminishes in aging, is considered an aging characteristic. Melatonin is an important hormone that plays a wide range of physiological functions, including the anti-aging effect, potentially via the regulation of the Sirtuin1 (SIRT1) pathway. The deacetylation ability of SIRT1 is important for controlling the function of several transcription factors, including nuclear factor kappa B (NF-ĸB). Apart from inflammation, NF-ĸB can regulate autophagy by inhibiting Beclin1, an initiator of autophagy. Although numerous studies have revealed the role of melatonin in regulating autophagy, very limited experiments have shown that melatonin can increase autophagic activity via SIRT1 in a senescent model. This study focuses on the effect of melatonin on autophagy via the deacetylation activity of SIRT1 on RelA/p65, a subunit of NF-ĸB, to determine whether melatonin can attenuate the aging condition. SH-SY5Y cells were treated with H 2 O 2 to induce the senescent state. These results demonstrated that melatonin reduced a number of beta-galactosidase (SA-βgal)-positive cells, a senescent marker. In addition, melatonin increased the protein levels of SIRT1, Beclin1, and LC3-II, a hallmark protein of autophagy, and reduced the levels of acetylated-Lys310 in the p65 subunit of NF-ĸB in SH-SY5Y cells treated with H 2 O 2 . Furthermore, in the presence of SIRT1 inhibitor, melatonin failed to increase autophagic markers. The present data indicate that melatonin enhances autophagic activity via the SIRT1 signaling pathway. Taken together, we propose that in modulating autophagy, melatonin may provide a therapeutically beneficial role in the anti-aging processes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Endothelial sirtuin 1 deficiency perpetrates nephrosclerosis through downregulation of matrix metalloproteinase-14: relevance to fibrosis of vascular senescence.

    Science.gov (United States)

    Vasko, Radovan; Xavier, Sandhya; Chen, Jun; Lin, Chi Hua Sarah; Ratliff, Brian; Rabadi, May; Maizel, Julien; Tanokuchi, Rina; Zhang, Frank; Cao, Jian; Goligorsky, Michael S

    2014-02-01

    Sirtuin 1 (SIRT1) depletion in vascular endothelial cells mediates endothelial dysfunction and premature senescence in diverse cardiovascular and renal diseases. However, the molecular mechanisms underlying these pathologic effects remain unclear. Here, we examined the phenotype of a mouse model of vascular senescence created by genetically ablating exon 4 of Sirt1 in endothelial cells (Sirt1(endo-/-)). Under basal conditions, Sirt1(endo-/-) mice showed impaired endothelium-dependent vasorelaxation and angiogenesis, and fibrosis occurred spontaneously at low levels at an early age. In contrast, induction of nephrotoxic stress (acute and chronic folic acid-induced nephropathy) in Sirt1(endo-/-) mice resulted in robust acute renal functional deterioration followed by an exaggerated fibrotic response compared with control animals. Additional studies identified matrix metalloproteinase-14 (MMP-14) as a target of SIRT1. In the kidneys of Sirt1(endo-/-) mice, impaired angiogenesis, reduced matrilytic activity, and retention of the profibrotic cleavage substrates tissue transglutaminase and endoglin accompanied MMP-14 suppression. Furthermore, restoration of MMP-14 expression in SIRT1-depeleted mice improved angiogenic and matrilytic functions of the endothelium, prevented renal dysfunction, and attenuated nephrosclerosis. Our findings establish a novel mechanistic molecular link between endothelial SIRT1 depletion, downregulation of MMP-14, and the development of nephrosclerosis.

  2. Adipose tissue NAD+-homeostasis, sirtuins and poly(ADP-ribose) polymerases -important players in mitochondrial metabolism and metabolic health.

    Science.gov (United States)

    Jokinen, Riikka; Pirnes-Karhu, Sini; Pietiläinen, Kirsi H; Pirinen, Eija

    2017-08-01

    Obesity, a chronic state of energy overload, is characterized by adipose tissue dysfunction that is considered to be the major driver for obesity associated metabolic complications. The reasons for adipose tissue dysfunction are incompletely understood, but one potential contributing factor is adipose tissue mitochondrial dysfunction. Derangements of adipose tissue mitochondrial biogenesis and pathways associate with obesity and metabolic diseases. Mitochondria are central organelles in energy metabolism through their role in energy derivation through catabolic oxidative reactions. The mitochondrial processes are dependent on the proper NAD + /NADH redox balance and NAD + is essential for reactions catalyzed by the key regulators of mitochondrial metabolism, sirtuins (SIRTs) and poly(ADP-ribose) polymerases (PARPs). Notably, obesity is associated with disturbed adipose tissue NAD + homeostasis and the balance of SIRT and PARP activities. In this review we aim to summarize existing literature on the maintenance of intracellular NAD + pools and the function of SIRTs and PARPs in adipose tissue during normal and obese conditions, with the purpose of comprehending their potential role in mitochondrial derangements and obesity associated metabolic complications. Understanding the molecular mechanisms that are the root cause of the adipose tissue mitochondrial derangements is crucial for developing new effective strategies to reverse obesity associated metabolic complications. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid vinyl-ACCA) derivatives: key intermediates for the preparation of inhibitors of the hepatitis C virus NS3 protease.

    Science.gov (United States)

    Beaulieu, Pierre L; Gillard, James; Bailey, Murray D; Boucher, Colette; Duceppe, Jean-Simon; Simoneau, Bruno; Wang, Xiao-Jun; Zhang, Li; Grozinger, Karl; Houpis, Ioannis; Farina, Vittorio; Heimroth, Heidi; Krueger, Thomas; Schnaubelt, Jürgen

    2005-07-22

    (1R,2S)-1-Amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is a key building block in the synthesis of potent inhibitors of the hepatitis C virus NS3 protease such as BILN 2061, which was recently shown to dramatically reduce viral load after administration to patients infected with HCV genotype 1. We have developed a scalable process that delivers derivatives of this unusual amino acid in >99% ee. The strategy was based on the dialkylation of a glycine Schiff base using trans-1,4-dibromo-2-butene as an electrophile to produce racemic vinyl-ACCA, which was subsequently resolved using a readily available, inexpensive esterase enzyme (Alcalase 2.4L). Factors that affect diastereoselection in the initial dialkylation steps were examined and the conditions optimized to deliver the desired diastereomer selectively. Product inhibition, which was encountered during the enzymatic resolution step, initially resulted in prolonged cycle times. Enrichment of racemic vinyl-ACCA through a chemical resolution via diastereomeric salt formation or the use of forcing conditions in the enzymatic reaction both led to improvements in throughput and the development of a viable process. The chemistry described herein was scaled up to produce multikilogram quantities of this building block.

  4. Imidazo[1,2-c]pyrimidin-5(6H)-one as a novel core of cyclin-dependent kinase 2 inhibitors: Synthesis, activity measurement, docking, and quantum mechanical scoring.

    Science.gov (United States)

    Ajani, Haresh; Jansa, Josef; Köprülüoğlu, Cemal; Hobza, Pavel; Kryštof, Vladimír; Lyčka, Antonín; Lepsik, Martin

    2018-04-23

    We report on the synthesis, activity testing, docking, and quantum mechanical scoring of novel imidazo[1,2-c]pyrimidin-5(6H)-one scaffold for cyclin-dependent kinase 2 (CDK2) inhibition. A series of 26 compounds substituted with aromatic moieties at position 8 has been tested in in vitro enzyme assays and shown to inhibit CDK2. 2D structure-activity relationships have ascertained that small substituents at position 8 (up to the size of naphtyl or methoxyphenyl) generally lead to single-digit micromolar IC 50 values, whereas bigger substituents (substituted biphenyls) decreased the compounds' activities. The binding modes of the compounds obtained using Glide docking have exhibited up to 2 hinge-region hydrogen bonds to CDK2 and differed in the orientation of the inhibitor core and the placement of the 8-substituents. Semiempirical quantum mechanics-based scoring identified probable favourable binding modes, which will serve for future structure-based design and synthetic optimization of substituents of the heterocyclic core. In summary, we have identified a novel core for CDK2 inhibition and will explore it further to increase the potencies of the compounds and also monitor selectivities against other protein kinases. Copyright © 2018 John Wiley & Sons, Ltd.

  5. Synthesis of Selective Butyrylcholinesterase Inhibitors Coupled between α-Lipoic Acid and Polyphenols by Using 2-(Piperazin-1-yl)ethanol Linker

    Energy Technology Data Exchange (ETDEWEB)

    Yeun, Go Heun; Lee, Seung Hwan; LIm, Yong Bae; Lee, Hye Sook; Lee, Bong Ho; Park, Jeong Ho [Hanbat National Univ., Daejeon (Korea, Republic of); Won, Mooho [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2013-04-15

    In the previous paper (Bull. Korean Chem. Soc., 2011, 32, 2997), the hybrid molecules between α-lipoic acid (ALA) and polyphenols (PPs) connected with neutral 2-(2-aminoethoxy)ethanol linker (linker-1) showed new biological activity such as butyrylcholinesterase (BuChE) inhibition. In order to increase the binding affinity of the hybrid compounds to cholinesterase (ChE), the neutral 2-(2-aminoethoxy)ethanol (linker 1) was switched to the cationic 2-(piperazin-1-yl)ethanol linker (linker 2). The IC{sub 50} values of the linker-2 hybrid molecules for BuChE inhibition were lower than those of linker-1 hybrid molecules (except 9-2) and they also had the same great selectivity for BuChE over AChE (> 800 fold) as linker-1 hybrid molecules. ALA-acetyl caffeic acid (10-2, ALA-AcCA) was shown as an effective inhibitor of BuChE (IC{sub 50} = 0.44 ± 0.24 μM). A kinetic study using 7-2 showed that it is the same mixed type inhibition as 7-1. Its inhibition constant (Ki) to BuChE is 4.3 ± 0.09 μM.

  6. Synthesis and discovery of potent carbonic anhydrase, acetylcholinesterase, butyrylcholinesterase, and α-glycosidase enzymes inhibitors: The novel N,N'-bis-cyanomethylamine and alkoxymethylamine derivatives.

    Science.gov (United States)

    Taslimi, Parham; Caglayan, Cuneyt; Farzaliyev, Vagif; Nabiyev, Oruj; Sujayev, Afsun; Turkan, Fikret; Kaya, Ruya; Gulçin, İlhami

    2018-04-01

    During this investigation, N,N'-bis-azidomethylamines, N,N'-bis-cyanomethylamine, new alkoxymethylamine and chiral derivatives, which are considered to be a new generation of multifunctional compounds, were synthesized, functional properties were investigated, and anticholinergic and antidiabetic properties of those compounds were studied through the laboratory tests, and it was approved that they contain physiologically active compounds rather than analogues. Novel N-bis-cyanomethylamine and alkoxymethylamine derivatives were effective inhibitors of the α-glycosidase, cytosolic carbonic anhydrase I and II isoforms, butyrylcholinesterase (BChE), and acetylcholinesterase (AChE) with K i values in the range of 0.15-13.31 nM for α-glycosidase, 2.77-15.30 nM for human carbonic anhydrase isoenzymes I (hCA I), 3.12-21.90 nM for human carbonic anhydrase isoenzymes II (hCA II), 23.33-73.23 nM for AChE, and 3.84-48.41 nM for BChE, respectively. Indeed, the inhibition of these metabolic enzymes has been considered as a promising factor for pharmacologic intervention in a diversity of disturbances. © 2018 Wiley Periodicals, Inc.

  7. Synthesis, biological evaluation and in silico studies of 5-(3-methoxybenzylidene)thiazolidine-2,4-dione analogues as PTP1B inhibitors.

    Science.gov (United States)

    Mahapatra, Manoj Kumar; Kumar, Rajnish; Kumar, Manoj

    2017-04-01

    PTP1B (protein tyrosine phosphatase 1B) dephosphorylates the insulin receptor substrate and thus acts as a negative regulator of the insulin and leptin signalling pathway. Recently, it has been considered as a new therapeutic target of intervention for the treatment of type2 diabetes. A series of aryl/alkylsulfonyloxy-5-(3-methoxybenzylidene)thiazolidine-2,4-dione derivatives were synthesized, screened in vitro for their PTP1B inhibitory activity and in vivo for anti-hyperglycaemic activity. Docking results further helped in understanding the nature of interactions governing the binding mode of ligands inside the active site of PTP1B. Among the synthesized compounds, 13 and 16 were found to be potent PTP1B inhibitors having IC 50 of 7.31 and 8.73μM respectively. Significant lowering of blood glucose level was observed in some of the synthesized compounds in in vivo study. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Synthesis, radiosynthesis, in vitro and preliminary in vivo evaluation of biphenyl carboxylic and hydroxamic matrix metalloproteinase (MMP) inhibitors as potential tumor imaging agents

    International Nuclear Information System (INIS)

    Oltenfreiter, Ruth; Staelens, Ludovicus; Hillaert, Ulrik; Heremans, An; Noel, Agnes; Frankenne, Francis; Slegers, Guido

    2005-01-01

    Excess matrix degradation is one of the hallmarks of cancer and is an important factor in the process of tumor progression. It is implicated in invasion, metastasis, growth, angiogenesis and migration. Many characteristics of matrix metalloproteinases (MMPs) make them attractive therapeutic and diagnostic targets. MMP expression is upregulated at the tumor site, with localization of activity in the tumor or the surrounding stroma, providing a target for medical imaging techniques. Radioiodinated carboxylic and hydroxamic MMP inhibitors 2-(4'-[ 123 I] iodo-biphenyl-4-sulfonylamino)-3-methyl-butyric acid (9) and 2-(4'-[ 123 I] iodo-biphenyl-4-sulfonylamino)-3-methyl-butyramide (11), their unlabelled standards and precursors were synthesized. Radioiodination was conducted by electrophilic aromatic substitution of the tributylstannyl precursors and resulted in radiochemical yields of 70+/-5% (n=6) and 60+/-5% (n=4), respectively. In vitro zymography and enzyme assays showed for both hydroxamic acid and carboxylic acid compounds a good inhibition activity and a high selectivity for MMP-2. In vivo biodistribution in NMRI mice showed no long-term accumulation in organs and the possibility to accumulate in the tumor in a later phase of this study

  9. Synthesis, radiosynthesis, in vitro and preliminary in vivo evaluation of biphenyl carboxylic and hydroxamic matrix metalloproteinase (MMP) inhibitors as potential tumor imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Oltenfreiter, Ruth [Laboratory of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium)]. E-mail: ruth.oltenfreiter@ugent.be; Staelens, Ludovicus [Laboratory of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium); Hillaert, Ulrik [Laboratory for Medicinal Chemistry, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium); Heremans, An; Noel, Agnes [Laboratory of Tumor and Developmental Biology, University of Liege, Sart-Tilman, Liege (Belgium); Frankenne, Francis [Laboratory of Tumor and Developmental Biology, University of Liege, Sart-Tilman, Liege (Belgium); Slegers, Guido [Laboratory of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium)

    2005-06-01

    Excess matrix degradation is one of the hallmarks of cancer and is an important factor in the process of tumor progression. It is implicated in invasion, metastasis, growth, angiogenesis and migration. Many characteristics of matrix metalloproteinases (MMPs) make them attractive therapeutic and diagnostic targets. MMP expression is upregulated at the tumor site, with localization of activity in the tumor or the surrounding stroma, providing a target for medical imaging techniques. Radioiodinated carboxylic and hydroxamic MMP inhibitors 2-(4'-[{sup 123}I] iodo-biphenyl-4-sulfonylamino)-3-methyl-butyric acid (9) and 2-(4'-[{sup 123}I] iodo-biphenyl-4-sulfonylamino)-3-methyl-butyramide (11), their unlabelled standards and precursors were synthesized. Radioiodination was conducted by electrophilic aromatic substitution of the tributylstannyl precursors and resulted in radiochemical yields of 70+/-5% (n=6) and 60+/-5% (n=4), respectively. In vitro zymography and enzyme assays showed for both hydroxamic acid and carboxylic acid compounds a good inhibition activity and a high selectivity for MMP-2. In vivo biodistribution in NMRI mice showed no long-term accumulation in organs and the possibility to accumulate in the tumor in a later phase of this study.

  10. Sulfonamide-Linked Ciprofloxacin, Sulfadiazine and Amantadine Derivatives as a Novel Class of Inhibitors of Jack Bean Urease; Synthesis, Kinetic Mechanism and Molecular Docking.

    Science.gov (United States)

    Channar, Pervaiz Ali; Saeed, Aamer; Albericio, Fernando; Larik, Fayaz Ali; Abbas, Qamar; Hassan, Mubashir; Raza, Hussain; Seo, Sung-Yum

    2017-08-16

    Sulfonamide derivatives serve as an important building blocks in the drug design discovery and development (4D) process. Ciprofloxacin-, sulfadiazine- and amantadine-based sulfonamides were synthesized as potent inhibitors of jack bean urease and free radical scavengers. Molecular diversity was explored and electronic factors were also examined. All 24 synthesized compounds exhibited excellent potential against urease enzyme. Compound 3e (IC 50 = 0.081 ± 0.003 µM), 6a (IC 50 = 0.0022 ± 0.0002 µM), 9e (IC 50 = 0.0250 ± 0.0007 µM) and 12d (IC 50 = 0.0266 ± 0.0021 µM) were found to be the lead compounds compared to standard (thiourea, IC 50 = 17.814 ± 0.096 µM). Molecular docking studies were performed to delineate the binding affinity of the molecules and a kinetic mechanism of enzyme inhibition was propounded. Compounds 3e , 6a and 12d exhibited a mixed type of inhibition, while derivative 9e revealed a non-competitive mode of inhibition. Compounds 12a , 12b , 12d , 12e and 12f showed excellent radical scavenging potency in comparison to the reference drug vitamin C.

  11. Searching for Novel Inhibitors of the S. aureus NorA Efflux Pump: Synthesis and Biological Evaluation of the 3-Phenyl-1,4-benzothiazine Analogues.

    Science.gov (United States)

    Felicetti, Tommaso; Cannalire, Rolando; Burali, Maria Sole; Massari, Serena; Manfroni, Giuseppe; Barreca, Maria Letizia; Tabarrini, Oriana; Schindler, Bryan D; Sabatini, Stefano; Kaatz, Glenn W; Cecchetti, Violetta

    2017-08-22

    Bacterial resistance to antimicrobial agents has become an increasingly serious health problem in recent years. Among the strategies by which resistance can be achieved, overexpression of efflux pumps such as NorA of Staphylococcus aureus leads to a sub-lethal concentration of the antibacterial agent at the active site that in turn may predispose the organism to the development of high-level target-based resistance. With an aim to improve both the chemical stability and potency of our previously reported 3-phenyl-1,4-benzothiazine NorA inhibitors, we replaced the benzothiazine core with different nuclei. None of the new synthesized compounds showed any appreciable intrinsic antibacterial activity, and, in particular, 2-(3,4-dimethoxyphenyl)quinoline (6 c) was able to decrease, in a concentration-dependent manner, the ciprofloxacin MIC against the norA-overexpressing strains S. aureus SA-K2378 (norA++) and SA-1199B (norA+/A116E GrlA). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Novel N-allyl/propargyl tetrahydroquinolines: Synthesis via Three-component Cationic Imino Diels-Alder Reaction, Binding Prediction, and Evaluation as Cholinesterase Inhibitors.

    Science.gov (United States)

    Rodríguez, Yeray A; Gutiérrez, Margarita; Ramírez, David; Alzate-Morales, Jans; Bernal, Cristian C; Güiza, Fausto M; Romero Bohórquez, Arnold R

    2016-10-01

    New N-allyl/propargyl 4-substituted 1,2,3,4-tetrahydroquinolines derivatives were efficiently synthesized using acid-catalyzed three components cationic imino Diels-Alder reaction (70-95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl-cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC50 = 72 μm) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl-cholinesterase was exhibited by compound 4ae (IC50 = 25.58 μm) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl-cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets. © 2016 The Authors Chemical Biology & Drug Design Published by John Wiley & Sons Ltd.

  13. New pyrrole inhibitors of monoamine oxidase: synthesis, biological evaluation, and structural determinants of MAO-A and MAO-B selectivity.

    Science.gov (United States)

    La Regina, Giuseppe; Silvestri, Romano; Artico, Marino; Lavecchia, Antonio; Novellino, Ettore; Befani, Olivia; Turini, Paola; Agostinelli, Enzo

    2007-03-08

    A series of new pyrrole derivatives have been synthesized and evaluated for their monoamine oxidase (MAO) A and B inhibitory activity and selectivity. N-Methyl,N-(benzyl),N-(pyrrol-2-ylmethyl)amine (7) and N-(2-benzyl),N-(1-methylpyrrol-2-ylmethyl)amine (18) were the most selective MAO-B (7, SI = 0.0057) and MAO-A (18, SI = 12500) inhibitors, respectively. Docking and molecular dynamics simulations gave structural insights into the MAO-A and MAO-B selectivity. Compound 18 forms an H-bond with Gln215 through its protonated amino group into the MAO-A binding site. This H-bond is absent in the 7/MAO-A complex. In contrast, compound 7 places its phenyl ring into an aromatic cage of the MAO-B binding pocket, where it forms charge-transfer interactions. The slightly different binding pose of 18 into the MAO-B active site seems to be forced by a bulkier Tyr residue, which replaces a smaller Ile residue present in MAO-A.

  14. Synthesis of Selective Butyrylcholinesterase Inhibitors Coupled between α-Lipoic Acid and Polyphenols by Using 2-(Piperazin-1-yl)ethanol Linker

    International Nuclear Information System (INIS)

    Yeun, Go Heun; Lee, Seung Hwan; LIm, Yong Bae; Lee, Hye Sook; Lee, Bong Ho; Park, Jeong Ho; Won, Mooho

    2013-01-01

    In the previous paper (Bull. Korean Chem. Soc., 2011, 32, 2997), the hybrid molecules between α-lipoic acid (ALA) and polyphenols (PPs) connected with neutral 2-(2-aminoethoxy)ethanol linker (linker-1) showed new biological activity such as butyrylcholinesterase (BuChE) inhibition. In order to increase the binding affinity of the hybrid compounds to cholinesterase (ChE), the neutral 2-(2-aminoethoxy)ethanol (linker 1) was switched to the cationic 2-(piperazin-1-yl)ethanol linker (linker 2). The IC 50 values of the linker-2 hybrid molecules for BuChE inhibition were lower than those of linker-1 hybrid molecules (except 9-2) and they also had the same great selectivity for BuChE over AChE (> 800 fold) as linker-1 hybrid molecules. ALA-acetyl caffeic acid (10-2, ALA-AcCA) was shown as an effective inhibitor of BuChE (IC 50 = 0.44 ± 0.24 μM). A kinetic study using 7-2 showed that it is the same mixed type inhibition as 7-1. Its inhibition constant (Ki) to BuChE is 4.3 ± 0.09 μM

  15. Discovery of imidazopyridines containing isoindoline-1,3-dione framework as a new class of BACE1 inhibitors: Design, synthesis and SAR analysis.

    Science.gov (United States)

    Azimi, Sara; Zonouzi, Afsaneh; Firuzi, Omidreza; Iraji, Aida; Saeedi, Mina; Mahdavi, Mohammad; Edraki, Najmeh

    2017-09-29

    Alzheimer's disease is characterized by chronic neurodegeneration leading to dementia. The main cause of neurodegeneration is considered to be the accumulation of amyloid-β. Inhibiting BACE1 is a well-studied approach to lower the burden of amyloid-β aggregates. We designed a series of imidazopyridines-based compounds bearing phthalimide moieties as inhibitors of BACE1. The compounds 8a-o were synthesized by the Groebke-Blackburn-Bienaymé three-component reaction of heteroaromatic amidines, aldehydes and isocyanides. Evaluating the BACE1 inhibitory effects of the synthesized compounds revealed that introducing an aminocyclohexyl moiety in the imidazopyridine core resulted in a significant improvement in its BACE1 inhibitory potential. In this regard, compound 8e was the most potent against BACE1 with an IC 50 value of 2.84 (±0.95) μM. Molecular docking revealed that the nitrogen atom of imidazopyridines and the oxygen atom of the phenoxypropyl linker were involved in hydrogen bound interactions with Asp228 and Asp32 of BACE1 active site, respectively. The phthalimide moiety oriented toward the flap pocket and interacted with phe108, lle110, Trp115, Ile118 through van der Waal's and hydrophobic interactions. These findings demonstrate that imidazopyridines-based compounds bearing phthalimide moiety have the potential to decrease amyloid-β levels and ameliorate the symptoms of Alzheimer's disease. Copyright © 2017. Published by Elsevier Masson SAS.

  16. Design, synthesis and evaluation of novel cinnamic acid derivatives bearing N-benzyl pyridinium moiety as multifunctional cholinesterase inhibitors for Alzheimer's disease.

    Science.gov (United States)

    Lan, Jin-Shuai; Hou, Jian-Wei; Liu, Yun; Ding, Yue; Zhang, Yong; Li, Ling; Zhang, Tong

    2017-12-01

    A novel family of cinnamic acid derivatives has been developed to be multifunctional cholinesterase inhibitors against AD by fusing N-benzyl pyridinium moiety and different substituted cinnamic acids. In vitro studies showed that most compounds were endowed with a noteworthy ability to inhibit cholinesterase, self-induced Aβ (1-42) aggregation, and to chelate metal ions. Especially, compound 5l showed potent cholinesterase inhibitory activity (IC 50 , 12.1 nM for eeAChE, 8.6 nM for hAChE, 2.6 μM for eqBuChE and 4.4 μM for hBuChE) and the highest selectivity toward AChE over BuChE. It also showed good inhibition of Aβ (1-42) aggregation (64.7% at 20 μM) and good neuroprotection on PC12 cells against amyloid-induced cell toxicity. Finally, compound 5l could penetrate the BBB, as forecasted by the PAMPA-BBB assay and proved in OF1 mice by ex vivo experiments. Overall, compound 5l seems to be a promising lead compound for the treatment of Alzheimer's diseases.

  17. Design, synthesis and biological evaluation of phthalimide-alkylamine derivatives as balanced multifunctional cholinesterase and monoamine oxidase-B inhibitors for the treatment of Alzheimer's disease.

    Science.gov (United States)

    Sang, Zhipei; Wang, Keren; Wang, Huifang; Yu, Lintao; Wang, Huijuan; Ma, Qianwen; Ye, Mengyao; Han, Xue; Liu, Wenmin

    2017-11-15

    A series of novel phthalimide-alkylamine derivatives were synthesized and evaluated as multi-functions inhibitors for the treatment of Alzheimer's disease (AD). The results showed that compound TM-9 could be regarded as a balanced multi-targets active molecule. It exhibited potent and balanced inhibitory activities against ChE and MAO-B (huAChE, huBuChE, and huMAO-B with IC 50 values of 1.2μM, 3.8μM and 2.6 μM, respectively) with low selectivity. Both kinetic analysis of AChE inhibition and molecular modeling study suggested that TM-9 binds simultaneously to the catalytic active site and peripheral anionic site of AChE. Interestingly, compound TM-9 abided by Lipinski's rule of five. Furthermore, our investigation proved that TM-9 indicated weak cytotoxicity, and it could cross the blood-brain barrier (BBB) in vitro. The results suggest that compound TM-9, an interesting multi-targeted active molecule, offers an attractive starting point for further lead optimization in the drug-discovery process against Alzheimer's disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Synthesis, cytotoxicity, cellular uptake and influence on eicosanoid metabolism of cobalt-alkyne modified fructoses in comparison to auranofin and the cytotoxic COX inhibitor Co-ASS.

    Science.gov (United States)

    Ott, Ingo; Koch, Thao; Shorafa, Hashem; Bai, Zhenlin; Poeckel, Daniel; Steinhilber, Dieter; Gust, Ronald

    2005-06-21

    Propargylhexacarbonyldicobalt complexes with fructopyranose ligands were prepared and investigated for cytotoxicity in the MCF-7 human breast cancer cell line. The antiproliferative effects depended on the presence of isopropylidene protecting groups in the carbohydrate ligand and correlated with the cellular concentration of the complexes. IC(50) values of > 20 microM demonstrated that the fructose derivatives were only moderately active compared to the references auranofin and the aspirin (ASS) derivative [2-acetoxy(2-propynyl)benzoate]hexacarbonyldicobalt (Co-ASS). In continuation of our studies on the mode of action of cobalt-alkyne complexes we studied the influence of the compounds on the formation of 12-HHT (COX-1 product) and 12-HETE (12-LOX product) by human platelets as an indication of the interference in the eicosanoid metabolism, which is discussed as a target system of cytostatics. Co-ASS was an efficient COX-1 inhibitor without LOX inhibitory activity and auranofin inhibited both COX-1 and 12-LOX eicosanoid production. The missing activity of the fructopyranose complexes at the 12-LOX and the only moderate effects at COX-1 indicate that COX/LOX inhibition may be in part responsible for the pharmacological effects of auranofin and Co-ASS but not for those of the fructopyranose complexes.

  19. Lack of a Functional VHL Gene Product Sensitizes Renal Cell Carcinoma Cells to the Apoptotic Effects of the Protein Synthesis Inhibitor Verrucarin A

    Directory of Open Access Journals (Sweden)

    Girma M. Woldemichael

    2012-08-01

    Full Text Available Verrucarin A (VA is a small molecule derived from the fungal plant pathogen Myrothecium verrucaria and was identified as a selective inhibitor of clear cell renal cell carcinoma (CCRCC cell proliferation in a high-throughput screen of a library of naturally occurring small molecules. CCRCC arises as a result of loss-of-function mutations in the von Hippel-Lindau (VHL gene. Here we show that VA inhibits protein translation initiation culminating in apoptosis through the extrinsic signaling pathway. Reintroduction of the VHL gene in CCRCC cells afforded resistance to VA's apoptotic effects. This resistance is mediated in part by the formation of stress granules that entrap signaling molecules that initiate the apoptotic signaling cascade. The VHL gene product was found to be a component of stress granules that develop as result of VA treatment. These findings reveal an important role for the VHL gene product in cytotoxic stress response and have important implications for the rational development of VA-related compounds in chemotherapeutic targeting of CCRCC.

  20. Lack of a functional VHL gene product sensitizes renal cell carcinoma cells to the apoptotic effects of the protein synthesis inhibitor verrucarin A.

    Science.gov (United States)

    Woldemichael, Girma M; Turbyville, Thomas J; Vasselli, James R; Linehan, W Marston; McMahon, James B

    2012-08-01

    Verrucarin A (VA) is a small molecule derived from the fungal plant pathogen Myrothecium verrucaria and was identified as a selective inhibitor of clear cell renal cell carcinoma (CCRCC) cell proliferation in a high-throughput screen of a library of naturally occurring small molecules. CCRCC arises as a result of loss-of-function mutations in the von Hippel-Lindau (VHL) gene. Here we show that VA inhibits protein translation initiation culminating in apoptosis through the extrinsic signaling pathway. Reintroduction of the VHL gene in CCRCC cells afforded resistance to VA's apoptotic effects. This resistance is mediated in part by the formation of stress granules that entrap signaling molecules that initiate the apoptotic signaling cascade. The VHL gene product was found to be a component of stress granules that develop as result of VA treatment. These findings reveal an important role for the VHL gene product in cytotoxic stress response and have important implications for the rational development of VA-related compounds in chemotherapeutic targeting of CCRCC.