Inhibitors of Fatty Acid Synthase for Prostate Cancer. Revision

Science.gov (United States)

2013-05-01

acetyl- cholinesterase inhibitors have been developed, many with femtomolar binding affinities (7). This body of literature also confirms that the...AD_________________ Award Number: W81XWH-09-1-0204 TITLE: Inhibitors of Fatty Acid Synthase for...May 2013 2. REPORT TYPE Revised Final 3. DATES COVERED 01 May 2009-30 Apr 2013 4. TITLE AND SUBTITLE Inhibitors of Fatty Acid Synthase for

Kynurenine aminotransferase III and glutamine transaminase L are identical enzymes that have cysteine S-conjugate β-lyase activity and can transaminate L-selenomethionine.

Science.gov (United States)

Pinto, John T; Krasnikov, Boris F; Alcutt, Steven; Jones, Melanie E; Dorai, Thambi; Villar, Maria T; Artigues, Antonio; Li, Jianyong; Cooper, Arthur J L

2014-11-07

Three of the four kynurenine aminotransferases (KAT I, II, and IV) that synthesize kynurenic acid, a neuromodulator, are identical to glutamine transaminase K (GTK), α-aminoadipate aminotransferase, and mitochondrial aspartate aminotransferase, respectively. GTK/KAT I and aspartate aminotransferase/KAT IV possess cysteine S-conjugate β-lyase activity. The gene for the former enzyme, GTK/KAT I, is listed in mammalian genome data banks as CCBL1 (cysteine conjugate beta-lyase 1). Also listed, despite the fact that no β-lyase activity has been assigned to the encoded protein in the genome data bank, is a CCBL2 (synonym KAT III). We show that human KAT III/CCBL2 possesses cysteine S-conjugate β-lyase activity, as does mouse KAT II. Thus, depending on the nature of the substrate, all four KATs possess cysteine S-conjugate β-lyase activity. These present studies show that KAT III and glutamine transaminase L are identical enzymes. This report also shows that KAT I, II, and III differ in their ability to transaminate methyl-L-selenocysteine (MSC) and L-selenomethionine (SM) to β-methylselenopyruvate (MSP) and α-ketomethylselenobutyrate, respectively. Previous studies have identified these seleno-α-keto acids as potent histone deacetylase inhibitors. Methylselenol (CH3SeH), also purported to have chemopreventive properties, is the γ-elimination product of SM and the β-elimination product of MSC catalyzed by cystathionine γ-lyase (γ-cystathionase). KAT I, II, and III, in part, can catalyze β-elimination reactions with MSC generating CH3SeH. Thus, the anticancer efficacy of MSC and SM will depend, in part, on the endogenous expression of various KAT enzymes and cystathionine γ-lyase present in target tissue coupled with the ability of cells to synthesize in situ either CH3SeH and/or seleno-keto acid metabolites. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Porcine alanine transaminase after liver allo-and xenotransplantation

OpenAIRE

Ekser, Burcin; Gridelli, Bruno; Cooper, David K.C.

2012-01-01

Aspartate transaminase (AST) and alanine transaminase (ALT) are measured following liver transplantation as indicators of hepatocellular injury. During a series of orthotopic liver allo-and xenotransplants, we observed that there was an increase in AST in all cases. The anticipated concomitant rise in ALT did not occur when a wild-type (WT) pig was the source of the liver graft, but did occur when a baboon or a genetically engineered (α1,3-galactosyltransferase gene-knockout [GTKO]) pig was t...

[The role of transaminases and mitochondrial anion porters in the energetics of animals of different ages].

Science.gov (United States)

Akhmerov, R N; Sultanov, Sh; Allamuratov, Sh I

1995-01-01

Aminohydroxyacetate, an inhibitor of aminotransferases, decreases the rate of oxygen consumption by 1-day-old young rats by 35% 10 min after intraperitoneal injection, whereas for 20-day-old rats, the inhibitory effect is 56%, and for adult mice, it is 83%. More prolonged exposure to aminohydroxyacetate leads to death of the animal. One-day-old rats die 90 min after the injection, 20-day-old rats die 30 min after the injection, and adult mice die 15 min after the injection. Butylmalonate (an inhibitor of mitochondrial dicarboxylate translocator) decreases the rate of energy metabolism to a lower extent, by 38% in adult mice and by 18% in 1-day-old rats. The animals generally remain alive after the exposure to this compound. 1,2,3-benzyltricarboxylate, an inhibitor of tricarboxylate transport, shows only a weak effect on energy metabolism of animals of any age. These results provide evidence that the role of the transaminase system in energy metabolism increases with age. Mechanisms underlying weak sensitivity of newborn animals to these inhibitors are discussed.

Genetics Home Reference: GABA-transaminase deficiency

Science.gov (United States)

... Description GABA-transaminase deficiency is a brain disease (encephalopathy) that begins in infancy. Babies with this disorder ... genetic testing? What is precision medicine? What is newborn screening? New Pages LMNA-related congenital muscular dystrophy ...

Screening of protein kinase inhibitors identifies PKC inhibitors as inhibitors of osteoclastic acid secretion and bone resorption

Directory of Open Access Journals (Sweden)

Boutin Jean A

2010-10-01

Full Text Available Abstract Background Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts. Methods Human osteoclasts were generated from CD14+ monocytes. The effect of different kinase inhibitors on lysosomal acidification in human osteoclasts was investigated using acridine orange for different incubation times (45 minutes, 4 and 24 hours. The inhibitors were tested in an acid influx assay using microsomes isolated from human osteoclasts. Bone resorption by human osteoclasts on bone slices was measured by calcium release. Cell viability was measured using AlamarBlue. Results Of the 51 compounds investigated only few inhibitors were positive in both acidification and resorption assays. Rottlerin, GF109203X, Hypericin and Ro31-8220 inhibited acid influx in microsomes and bone resorption, while Sphingosine and Palmitoyl-DL-carnitine-Cl showed low levels of inhibition. Rottlerin inhibited lysosomal acidification in human osteoclasts potently. Conclusions In conclusion, a group of inhibitors all indicated to inhibit PKC reduced acidification in human osteoclasts, and thereby bone resorption, indicating that acid secretion by osteoclasts may be specifically regulated by PKC in osteoclasts.

Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

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M. Yadav

2016-11-01

Full Text Available The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl-2-oleylimidazoline (AEOI and 1-(2-oleylamidoethyl-2-oleylimidazoline (OAEOI as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl and the corrosion inhibition of N80 steel in hydrochloric acid medium containing inhibitors was tested by weight loss, potentiodynamic polarization and AC impedance measurements. Influence of temperature (298–323 K on the inhibition behavior was studied. Surface studies were performed by using FTIR spectra and SEM. Both the inhibitors, AEOI and OAEOI at 150 ppm concentration show maximum efficiency 90.26% and 96.23%, respectively at 298 K in 15% HCl solution. Both the inhibitors act as mixed corrosion inhibitors. The adsorption of the corrosion inhibitors at the surface of N80 steel is the root cause of corrosion inhibition.

Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

OpenAIRE

M. Yadav; Debasis Behera; Usha Sharma

2016-01-01

The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl)-2-oleylimidazoline (AEOI) and 1-(2-oleylamidoethyl)-2-oleylimidazoline (OAEOI) as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl) and the corrosion inhibition of N80 steel in hydroch...

Complete amino acid sequence of bovine colostrum low-Mr cysteine proteinase inhibitor.

Science.gov (United States)

Hirado, M; Tsunasawa, S; Sakiyama, F; Niinobe, M; Fujii, S

1985-07-01

The complete amino acid sequence of bovine colostrum cysteine proteinase inhibitor was determined by sequencing native inhibitor and peptides obtained by cyanogen bromide degradation, Achromobacter lysylendopeptidase digestion and partial acid hydrolysis of reduced and S-carboxymethylated protein. Achromobacter peptidase digestion was successfully used to isolate two disulfide-containing peptides. The inhibitor consists of 112 amino acids with an Mr of 12787. Two disulfide bonds were established between Cys 66 and Cys 77 and between Cys 90 and Cys 110. A high degree of homology in the sequence was found between the colostrum inhibitor and human gamma-trace, human salivary acidic protein and chicken egg-white cystatin.

Aurintricarboxylic acid is a potent inhibitor of phosphofructokinase.

Science.gov (United States)

McCune, S A; Foe, L G; Kemp, R G; Jurin, R R

1989-01-01

Aurintricarboxylic acid (ATA) was found to be a very potent inhibitor of purified rabbit liver phosphofructokinase (PFK), giving 50% inhibition at 0.2 microM. The inhibition was in a manner consistent with interaction at the citrate-inhibitory site of the enzyme. The data suggest that inhibition of PFK by ATA was not due to denaturation of the enzyme or the irreversible binding of inhibitor, since the inhibition could be reversed by addition of allosteric activators of PFK, i.e. fructose 2,6-bisphosphate or AMP. Two other tricarboxylic acids, agaric acid and (-)-hydroxycitrate, were found to inhibit PFK. ATA at much higher concentrations (500 microM) was shown to inhibit fatty acid synthesis from endogenous glycogen in rat hepatocytes; however, protein synthesis was not altered. PMID:2525029

Evolutionary Diversification of Alanine Transaminases in Yeast: Catabolic Specialization and Biosynthetic Redundancy

Directory of Open Access Journals (Sweden)

Ximena Escalera-Fanjul

2017-06-01

Full Text Available Gene duplication is one of the major evolutionary mechanisms providing raw material for the generation of genes with new or modified functions. The yeast Saccharomyces cerevisiae originated after an allopolyploidization event, which involved mating between two different ancestral yeast species. ScALT1 and ScALT2 codify proteins with 65% identity, which were proposed to be paralogous alanine transaminases. Further analysis of their physiological role showed that while ScALT1 encodes an alanine transaminase which constitutes the main pathway for alanine biosynthesis and the sole pathway for alanine catabolism, ScAlt2 does not display alanine transaminase activity and is not involved in alanine metabolism. Moreover, phylogenetic studies have suggested that ScALT1 and ScALT2 come from each one of the two parental strains which gave rise to the ancestral hybrid. The present work has been aimed to the understanding of the properties of the ancestral type Lacchancea kluyveri LkALT1 and Kluyveromyces lactis KlALT1, alanine transaminases in order to better understand the ScALT1 and ScALT2 evolutionary history. These ancestral -type species were chosen since they harbor ALT1 genes, which are related to ScALT2. Presented results show that, although LkALT1 and KlALT1 constitute ScALT1 orthologous genes, encoding alanine transaminases, both yeasts display LkAlt1 and KlAlt1 independent alanine transaminase activity and additional unidentified alanine biosynthetic and catabolic pathway(s. Furthermore, phenotypic analysis of null mutants uncovered the fact that KlAlt1 and LkAlt1 have an additional role, not related to alanine metabolism but is necessary to achieve wild type growth rate. Our study shows that the ancestral alanine transaminase function has been retained by the ScALT1 encoded enzyme, which has specialized its catabolic character, while losing the alanine independent role observed in the ancestral type enzymes. The fact that ScAlt2 conserves 64

Should anti-inhibitor coagulant complex and tranexamic acid be used concomitantly?

Science.gov (United States)

Valentino, L A; Holme, P A

2015-11-01

Inhibitor development in haemophilia patients is challenging especially when undergoing surgical procedures. The development of an inhibitor precludes using factor VIII (FVIII) therapy thereby requiring a bypassing agent (BPA) for surgical bleeding prophylaxis if the FVIII inhibitor titre >5 BU. Concomitant use of anti-inhibitor coagulant complex (AICC) and tranexamic acid has been reported in the literature as a beneficial treatment for this population. Anti-inhibitor coagulant complex is known to cause an increase in thrombin generation and tranexamic acid inhibits fibrinolysis. Hence, the combined used of AICC and tranexamic acid has been limited due to safety concerns over possibilities of increased risk of thrombotic events and disseminated intravascular coagulation. However, the rationale for concomitant therapy is to obtain a potential synergistic effect and to increase clot stability. We conducted a literature review of past studies and individual case reports of concomitant use of AICC and tranexamic acid, which was extensively used during dental procedures. Evidence also exists for concomitant use of the combined therapy in orthopaedic procedures, control of gastrointestinal bleeding, epistaxis and cerebral haemorrhages. Some patients who received the combined therapy had failed monotherapy with a single BPA prior to combined therapy. There were no reports of thrombotic complications related to the concomitant therapy and haemostasis was achieved in all cases. Anti-inhibitor coagulant complex and tranexamic acid therapy was found to be safe, well-tolerated and effective therapy in haemophilia patients with inhibitors. Additional randomized controlled studies should be performed to confirm these findings. © 2015 John Wiley & Sons Ltd.

Acidic tumor microenvironment abrogates the efficacy of mTORC1 inhibitors.

Science.gov (United States)

Faes, Seraina; Duval, Adrian P; Planche, Anne; Uldry, Emilie; Santoro, Tania; Pythoud, Catherine; Stehle, Jean-Christophe; Horlbeck, Janine; Letovanec, Igor; Riggi, Nicolo; Demartines, Nicolas; Dormond, Olivier

2016-12-05

Blocking the mechanistic target of rapamycin complex-1 (mTORC1) with chemical inhibitors such as rapamycin has shown limited clinical efficacy in cancer. The tumor microenvironment is characterized by an acidic pH which interferes with cancer therapies. The consequences of acidity on the anti-cancer efficacy of mTORC1 inhibitors have not been characterized and are thus the focus of our study. Cancer cell lines were treated with rapamycin in acidic or physiological conditions and cell proliferation was investigated. The effect of acidity on mTORC1 activity was determined by Western blot. The anticancer efficacy of rapamycin in combination with sodium bicarbonate to increase the intratumoral pH was tested in two different mouse models and compared to rapamycin treatment alone. Histological analysis was performed on tumor samples to evaluate proliferation, apoptosis and necrosis. Exposing cancer cells to acidic pH in vitro significantly reduced the anti-proliferative effect of rapamycin. At the molecular level, acidity significantly decreased mTORC1 activity, suggesting that cancer cell proliferation is independent of mTORC1 in acidic conditions. In contrast, the activation of mitogen-activated protein kinase (MAPK) or AKT were not affected by acidity, and blocking MAPK or AKT with a chemical inhibitor maintained an anti-proliferative effect at low pH. In tumor mouse models, the use of sodium bicarbonate increased mTORC1 activity in cancer cells and potentiated the anti-cancer efficacy of rapamycin. Combining sodium bicarbonate with rapamycin resulted in increased tumor necrosis, increased cancer cell apoptosis and decreased cancer cell proliferation as compared to single treatment. Taken together, these results emphasize the inefficacy of mTORC1 inhibitors in acidic conditions. They further highlight the potential of combining sodium bicarbonate with mTORC1 inhibitors to improve their anti-tumoral efficacy.

Ginger extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

Science.gov (United States)

Fidrusli, A.; Suryanto; Mahmood, M.

2018-01-01

Ginger extract as corrosion inhibitor from natural resources was studied to prevent corrosion of mild steel in acid media. Ginger rhizome was extracted to produce green corrosion inhibitor (G-1) while ginger powder bought at supermarket was also extract to form green corrosion inhibitor (G-2). Effectiveness of inhibitor in preventing corrosion process of mild steel was studied in 1.0 M of hydrochloric acid. The experiment of weight loss method and polarization technique were conducted to measure corrosion rate and inhibition efficiency of mild steel in solution containing 1.0 M of hydrochloric acid with various concentration of inhibitor at room temperature. The results showed that, the rate of corrosion dropped from 8.09 mmpy in solution containing no inhibitor to 0.72 mmpy in solution containing 150g/l inhibitor while inhibition efficiency up to 91% was obtained. The polarization curve in polarization experiments shows that the inhibition efficiency is 86% with high concentration of inhibitor. The adsorption of ginger extract on the surface of mild steel was observed by using optical microscope and the characterization analysis was done by using pH measurement method. When high concentration of green inhibitor in the acid solution is used, the pH at the surface of steel is increasing.

Proton pump inhibitors reduce the size and acidity of the acid pocket in the stomach

NARCIS (Netherlands)

Rohof, Wout O.; Bennink, Roelof J.; Boeckxstaens, Guy E.

2014-01-01

The gastric acid pocket is believed to be the reservoir from which acid reflux events originate. Little is known about how changes in position, size, and acidity of the acid pocket contribute to the therapeutic effect of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease

Effect of inhibitors on acid production by baker's yeast.

Science.gov (United States)

Sigler, K; Knotková, A; Kotyk, A

1978-01-01

Glucose-induced acid extrusion, respiration and anaerobic fermentation in baker's yeast was studied with the aid of sixteen inhibitors. Uranyl(2+) nitrate affected the acid extrusion more anaerobically than aerobically; the complexing of Mg2+ and Ca2+ by EDTA at the membrane had no effect. Inhibitors of glycolysis (iodoacetamide, N-ethylmaleimide, fluoride) suppressed acid production markedly, and so did the phosphorylation-blocking arsenate. Fluoroacetate, inhibiting the citric-acid cycle, had no effect. Inhibition by uncouplers depended on their pKa values: 2,4,6-trinitrophenol (pKa 0.4) less than 2,4-dinitrophenol (4.1) less than azide (4.7) less than 3-chlorophenylhydrazonomalononitrile (6.0). Inhibition by trinitrophenol was only slightly increased by its acetylation. Cyanide and nonpermeant oligomycin showed practically no effect; inhibition by dicyclohexylcarbodiimide was delayed but potent. The concentration profiles of inhibition of acid production differed from those of respiration and fermentation. Thus, though the acid production is a metabolically dependent process, it does not reflect the intensity of metabolism, except partly in the first half of glycolysis.

Effect of some metabolic inhibitors on citric acid production Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Agrawal, P.K.; Bhatt, C.S.; Viswanathan, L.

1983-09-01

Stationary cultures of Aspergillus niger grown on a synthetic medium have been used to study the effect of some metabolic inhibitors on citric acid production. Addition of 0.05 to 1 mM sodium malonate or 0.01 to 0.1 mM potassium ferricyanide, iodoacetate, sodium azide, soldium arsenate or sodium fluoride stimulated citric acid production (3.6 to 45%), but not total titratable acids. Addition of higher concentrations (0.2 to 10 mM) of later inhibitors caused a marked inhibition of fungal growth and citric acid production. The implications of these preliminary findings are discussed. (Refs. 25).

Gamma rays induced mutation for low phytic acid and trypsin inhibitor content in soybean

International Nuclear Information System (INIS)

Gupta, S.K.; Manjaya, J.G.

2017-01-01

Soybean (Glycine max (L.) Merrill) is an important source of vegetable protein and is used as a food, feed and health supplement. However, consumption of soybean as food is limited because of the presence of many anti-nutritional factors. Trypsin inhibitors and phytic acid are two major anti-nutritional factors present in soybean that need to be removed for increasing the soybean consumption as food. Trypsin inhibitor is known to inhibit the trypsin/chymotrpsin activity and phytic acid reduces the bioavailability of essential micronutrients in digestive tract, resulting in adverse effect on health. Therefore, developing soybean cultivars having low trypsin inhibitors and phytic acid content is highly desirable. Soybean cultivar JS 93-05 was irradiated with 250 Gy gamma rays to induce mutation for various morphological and biochemical characters. A large number of mutants with altered morphological characters were identified. Ninety true breeding mutant lines in M6 generation were screened for trypsin inhibitor and phytic acid content. The phytic acid content was estimated using modified colorimetric method and trypsin inhibitor concentration was estimated using BAPNA as substrate in colorimetric method. The phytic acid content in the mutants varied from 7.59 to 24.14 mg g -1 . Two mutants lines TSG - 62 (7.59 mg g -1 ) and TSG - 66 (9.62 mg g -1 ) showed significant low phytic acid content as compared to the parent JS 93-05 (20.19 mg g -1 ). The trypsin inhibitor concentration in the mutants varied from 19.92 to 53.64 TIU mg -1 and one mutant line (TSG -14) was found with the lowest trypsin inhibitor concentration of 19.92 TIU mg -1 compared to parent JS 93-05 (50.90 TIU mg -1 ). The mutant lines identified in this study will serve as important genetic resources for developing low phytic acid and low trypsin inhibitor cultivars in soybean. (author)

The effect of increased branched-chain amino acid transaminase activity in yeast on the production of higher alcohols and on the flavour profiles of wine and distillates.

Science.gov (United States)

Lilly, Mariska; Bauer, Florian F; Styger, Gustav; Lambrechts, Marius G; Pretorius, Isak S

2006-08-01

In Saccharomyces cerevisiae, branched-chain amino acid transaminases (BCAATases) are encoded by the BAT1 and BAT2 genes. BCAATases catalyse the transfer of amino groups between those amino acids and alpha-keto-acids. alpha-Keto-acids are precursors for the biosynthesis of higher alcohols, which significantly influence the aroma and flavour of yeast-derived fermentation products. The objective of this study was to investigate the influence of BAT-gene expression on general yeast physiology, on aroma and flavour compound formation and on the sensory characteristics of wines and distillates. For this purpose, the genes were overexpressed and deleted in a laboratory strain, BY4742, and overexpressed in an industrial wine yeast strain, VIN13. The data show that, with the exception of a slow growth phenotype observed for the BAT1 deletion strain, the fermentation behaviour of the strains was unaffected by the modifications. The chemical and sensory analysis of fermentation products revealed a strong correction between BAT gene expression and the formation of many aroma compounds. The data suggest that the adjustment of BAT gene expression could play an important role in assisting winemakers in their endeavour to produce wines with specific flavour profiles.

A comparative study of glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) levels in the saliva of diabetic and normal patients.

Science.gov (United States)

Verma, M; Metgud, R; Madhusudan, A S; Verma, N; Saxena, M; Soni, A

2014-10-01

Diabetes has been reported to affect salivary glands adversely in humans and experimental models. Glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) are salivary enzymes that also are widely distributed in animal tissues. We determined GOT and GPT levels in saliva samples of 100 type 1 and 30 type 2 diabetic patients using reflectance spectrophotometry and compared them to 30 age and sex matched healthy controls. Statistically significant differences were observed in the mean values of GOT and GPT in type 1 diabetics compared to type 2 and control groups. Significantly higher GOT levels were found in the 1-20 year age group of type 1 diabetics. Our findings suggest that salivary gland damage is due to the same immunological attack that affects pancreatic β cells and results in type 1 diabetes.

A rational approach for ω-transaminase-catalyzed process design

DEFF Research Database (Denmark)

T. Gundersen, Maria; Lloyd, Richard; Tufvesson, Pär

Herein we describe a novel rational approach to the design of a ω-transaminase process such that it will fulfill criteria necessary for industrial use. By first determining the fundamental properties of the reaction system, it is possible to suggest appropriate process strategies that may be used...

Sodium phthalamates as corrosion inhibitors for carbon steel in aqueous hydrochloric acid solution

International Nuclear Information System (INIS)

Flores, Eugenio A.; Olivares, Octavio; Likhanova, Natalya V.; Dominguez-Aguilar, Marco A.; Nava, Noel; Guzman-Lucero, Diego; Corrales, Monica

2011-01-01

Highlights: → N-Alkyl-sodium phthalamates as corrosion inhibitors for industry in acidic medium. → Compounds behaved as mixed type inhibitors and followed Langmuir adsorption isotherm. → Efficiencies were proportional to aliphatic chain length and inhibitor concentration. → Iron complexes and chelates with phthalamates contributed to carbon steel protection. - Abstract: Three compounds of N-alkyl-sodium phthalamates were synthesized and tested as corrosion inhibitors for carbon steel in 0.5 M aqueous hydrochloric acid. Tests showed that inhibitor efficiencies were related to aliphatic chain length and dependent on concentration. N-1-n-tetradecyl-sodium phthalamate displayed moderate efficiency against uniform corrosion, 42-86% at 25 deg. C and 25-60% at 40 o C. Tests indicated that compounds behave as mixed type inhibitors where molecular adsorption on steel followed Langmuir isotherm, whereas thermodynamic suggested that a physisorption process occurred. XPS analysis confirmed film formation on surface, where Fe +2 complexes and Fe +2 chelates with phthalamates prevented steel from further corrosion.

Scoparic acid A, a beta-glucuronidase inhibitor from Scoparia dulcis.

Science.gov (United States)

Hayashi, T; Kawasaki, M; Okamura, K; Tamada, Y; Morita, N; Tezuka, Y; Kikuchi, T; Miwa, Y; Taga, T

1992-12-01

The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor.

Polyaspartic acid as a green corrosion inhibitor for carbon steel

Energy Technology Data Exchange (ETDEWEB)

Cui, R. [Department of Chemistry, Hebei Normal University, Shijiazhuang 050016 (China); Department of Chemistry and Materials Engineering, Changshu Institute of Technology, Changshu 215500 (China); Gu, N.; Li, C. [Department of Chemistry, Hebei Normal University, Shijiazhuang 050016 (China)

2011-04-15

The inhibitor effect of the environmentally friendly corrosion inhibitor polyaspartic acid (PASP) on the corrosion of carbon steel in 0.5 M H{sub 2}SO{sub 4} was investigated by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Polarization curve results clearly reveal the fact that PASP is a good anode-type inhibitor. EIS results confirm its corrosion inhibition ability. The inhibition efficiency increases with increasing PASP concentration, and the maximum inhibition efficiency was 80.33% at 10 C. SEM reveals that a protective film forms on the surface of the inhibited sample. The adsorption of this inhibitor is found to follow the Freundlich adsorption isotherm. A mechanism is proposed to explain the inhibitory action of the corrosion inhibitor. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Amino acid transamination is crucial for ischaemic cardioprotection in normal and preconditioned isolated rat hearts--focus on L-glutamate

DEFF Research Database (Denmark)

Løfgren, Bo; Povlsen, Jonas Agerlund; Rasmussen, Lars Ege

2010-01-01

We have found that cardioprotection by l-glutamate mimics protection by classical ischaemic preconditioning (IPC). We investigated whether the effect of IPC involves amino acid transamination and whether IPC modulates myocardial glutamate metabolism. In a glucose-perfused, isolated rat heart model...... subjected to 40 min global no-flow ischaemia and 120 min reperfusion, the effects of IPC (2 cycles of 5 min ischaemia and 5 min reperfusion) and continuous glutamate (20 mm) administration during reperfusion on infarct size and haemodynamic recovery were studied. The effect of inhibiting amino acid...... transamination was evaluated by adding the amino acid transaminase inhibitor amino-oxyacetate (AOA; 0.025 mm) during reperfusion. Changes in coronary effluent, interstitial (microdialysis) and intracellular glutamate ([GLUT](i)) concentrations were measured. Ischaemic preconditioning and postischaemic glutamate...

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.

Furfuryl alcohol as corrosion inhibitor for N80 steel in hydrochloric acid

International Nuclear Information System (INIS)

Vishwanatham, S.; Haldar, N.

2008-01-01

The ability of furfuryl alcohol (FA) as corrosion inhibitor in controlling corrosion of N80 steel in 15% hydrochloric acid has been investigated. It is found that the percentage inhibition of FA increases almost linearly with its concentration (in the range 10 mM-80 mM) and attains about 91% at 80 mM. FA shows significant inhibition at higher temperatures also (∼82% at 60 deg. C;∼74% at 110 deg. C with 80 mM concentration). FA undergoes acid catalyzed polymerization under the experimental conditions to give polyfurfuryl alcohols (PFA) as evidenced by FTIR and NMR spectral data. Thermodynamic parameters for the corrosion of steel in presence and absence of the inhibitor have been calculated. The inhibitive action may be attributed to adsorption of inhibitor molecules on the active sites of the metal surface following Temkin adsorption isotherm. Potentiodynamic polarization curves indicate that FA acts as mixed type inhibitor. A plausible mechanism for the mode of inhibition has been proposed

Metabolic inhibitors as stimulating factors for citric acid production

International Nuclear Information System (INIS)

Adham, N.Z.; Ahmed, E.M.; Refai, H.A.E.

2008-01-01

The effect of some metabolic inhibitors on citric acid (CA) production by Aspergillus niger in cane molasses medium was investigated. Addition of 0.01-0.1 mM iodoacetic acid and sodium arsenate, 0.05-1.0 mM sodium malonate, 0.01 mM sodium azide, 0.01-0.05 mM sodium fluoride, 0.1-1.0 mM EDTA stimulated CA production (5-49%). Higher concentrations (10 mM) of iodoacetic acid, sodium malonate and 0.5 mM sodium azide caused a complete inhibition of fungal growth, Iodoacetic acid, sodium arsenate and sodium fluoride (0.2 mM) caused a remarkable inhibition of CA production. The implications of those preliminary functions was discussed. (author)

Lysine sulfonamides as novel HIV-protease inhibitors: Nepsilon-acyl aromatic alpha-amino acids.

Science.gov (United States)

Stranix, Brent R; Lavallée, Jean-François; Sévigny, Guy; Yelle, Jocelyn; Perron, Valérie; LeBerre, Nicholas; Herbart, Dominik; Wu, Jinzi J

2006-07-01

A series of lysine sulfonamide analogues bearing Nepsilon-acyl aromatic amino acids were synthesized using an efficient synthetic route. Evaluation of these novel protease inhibitors revealed compounds with high potency against wild-type and multiple-protease inhibitor-resistant HIV viruses.

Dissociation of branched-chain alpha-keto acid dehydrogenase kinase (BDK) from branched-chain alpha-keto acid dehydrogenase complex (BCKDC) by BDK inhibitors.

Science.gov (United States)

Murakami, Taro; Matsuo, Masayuki; Shimizu, Ayako; Shimomura, Yoshiharu

2005-02-01

Branched-chain alpha-keto acid dehydrogenase kinase (BDK) phosphorylates and inactivates the branched-chain alpha-keto acid dehydrogenase complex (BCKDC), which is the rate-limiting enzyme in the branched-chain amino acid catabolism. BDK has been believed to be bound to the BCKDC. However, recent our studies demonstrated that protein-protein interaction between BDK and BCKDC is one of the factors to regulate BDK activity. Furthermore, only the bound form of BDK appears to have its activity. In the present study, we examined effects of BDK inhibitors on the amount of BDK bound to the BCKDC using rat liver extracts. The bound form of BDK in the extracts of liver from low protein diet-fed rats was measured by an immunoprecipitation pull down assay with or without BDK inhibitors. Among the BDK inhibitors. alpha-ketoisocaproate, alpha-chloroisocaproate, and a-ketoisovalerate released the BDK from the complex. Furthermore, the releasing effect of these inhibitors on the BDK appeared to depend on their inhibition constants. On the other hand, clofibric acid and thiamine pyrophosphate had no effect on the protein-protein interaction between two enzymes. These results suggest that the dissociation of the BDK from the BCKDC is one of the mechanisms responsible for the action of some inhibitors to BDK.

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.

Omega-3 Fatty Acids and a Novel Mammary Derived Growth Inhibitor Fatty Acid Binding Protein MRG in Suppression of Mammary Tumor

National Research Council Canada - National Science Library

Liu, Yiliang

2001-01-01

We have previously identified and characterized a novel tumor growth inhibitor and a fatty acid binding protein in human mammary gland and named it as Mammary derived growth inhibitor Related Gene MRG...

Corrosion inhibitors for aluminium in hydrochloric acid. Vanilline on aluminium 2S, 57S and 65S

Energy Technology Data Exchange (ETDEWEB)

Desai, M.N.

1972-12-01

So far, the only aldehyde reported in literature for the inhibition of the corrosion of aluminum in hydrochloric acid, is furfuraldehyde. This study reports vanilline as a corrosion inhibitor for aluminum alloys 2S, 57S, and 65S. These specifications for the alloys are listed. The influence of inhibitor concentration and time on inhibitor efficiency is given in tabular data and illustrated graphically. The corrosion of aluminum alloys 2S, 57S, and 65S increases with time and hydrochloric acid concentration. Polarization measurements indicate that the corrosion of aluminum alloys in hydrochloric acid is cathodically controlled. The behavior of vanilline as a corrosion inhibitor is very interesting. In 2.0N solution of hydrochloric acid, vanilline affords nearly complete protection (97 to 99%) to all the 3 aluminum alloys investigated up to 60 min. However, in 1.0N solutions of hydrochloric acid, the corrosion of aluminum 2S is severely accelerated by vanilline.

Porcine alanine transaminase after liver allo-and xenotransplantation.

Science.gov (United States)

Ekser, Burcin; Gridelli, Bruno; Cooper, David K C

2012-01-01

Aspartate transaminase (AST) and alanine transaminase (ALT) are measured following liver transplantation as indicators of hepatocellular injury. During a series of orthotopic liver allo-and xenotransplants, we observed that there was an increase in AST in all cases. The anticipated concomitant rise in ALT did not occur when a wild-type (WT) pig was the source of the liver graft, but did occur when a baboon or a genetically engineered (α1,3-galactosyltransferase gene-knockout [GTKO]) pig was the source of the graft. We hypothesized that the cience of Galα1,3Gal in GTKO pig livers may render pig hepatocytes similar to human and baboon hepatocytes in their response to hepatocellular injury. Reviewing the literature, after WT pig liver allotransplantation or xenotransplantation, in the majority of reports, although changes in AST were reported, no mention was made of changes in ALT, suggesting that there was no change in ALT. However, Ramirez et al. reported two cases of liver xenotransplants from hCD55 pigs, following which there were increases in both AST and ALT, suggesting that it is not simply the cience of expression of Galα1,3Gal that is the cause. We acknowledge that our observation is based on a small number of experiments, but we believe it is worth recording. © 2012 John Wiley & Sons A/S.

Electrochemical studies of novel corrosion inhibitor for mild steel in 1 M hydrochloric acid

Directory of Open Access Journals (Sweden)

Ahmed A. Al-Amiery

2018-06-01

Full Text Available The electrochemical performance of a novel organic corrosion inhibitor 6-(4-hydroxyphenyl-3-mercapto-7,8-dihydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine [HT3], for mild steel in 1 M hydrochloric acid is evaluated by potentiodynamic curves. The experimental results show that the investigated inhibitor [HT3], which can effectively retard the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing a protective coating for the mild steel that, can be weakened by increasing the temperature. Furthermore, the inhibition efficiency of [HT3] increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. Keywords: Corrosion, Inhibitor, Mild steel, Potentiodynamic polarization, HT3, NMR, FT-IR

The Effects of Subacute Exposure of Peracetic Acid on Lipid Peroxidation and Hepatic Enzymes in Wistar Rats

Directory of Open Access Journals (Sweden)

Abdoljalal Marjani

2010-10-01

Full Text Available Objectives: This study was undertaken to determine the effect of subacute exposure of peracetic acid on lipid peroxidation and hepatic enzymes in Wistar rats.Methods: 48 male animals in Treatment Group I, II and III received 0.2%, 2% and 20% peracetic acid daily for 2 and 4 weeks.Results: Serum malondialdehyde increased and Alanine Transaminase and Aspartate Transaminase decreased significantly in groups 2 and 3, compared to the control group. The malondialdehyde, Alanine Transaminase and Aspartate Transaminase with 0.2% and 2% doses of peracetic acid for 2 weeks do not lead to the alteration of malondialdehyde and enzyme activities.Conclusion: This study demonstrated that the enhancement of malondialdehyde could provide an oxidative damage induced by disinfectant peroxidation at 20% and 2% doses at 2 and 4 weeks. The consumption of peroxidation with 20% for 2 weeks and 2% for 4 weeks can cause the increase of malondialdehyde and the decrease of enzyme activities, respectively.

The Effects of Subacute Exposure of Peracetic Acid on Lipid Peroxidation and Hepatic Enzymes in Wistar Rats

Science.gov (United States)

Marjani, Abdoljalal; Golalipour, Mohammad J.; Gharravi, Anneh M.

2010-01-01

Objectives This study was undertaken to determine the effect of subacute exposure of peracetic acid on lipid peroxidation and hepatic enzymes in Wistar rats. Methods 48 male animals in Treatment Group I, II and III received 0.2%, 2% and 20% peracetic acid daily for 2 and 4 weeks. Results Serum malondialdehyde increased and Alanine Transaminase and Aspartate Transaminase decreased significantly in groups 2 and 3, compared to the control group. The malondialdehyde, Alanine Transaminase and Aspartate Transaminase with 0.2% and 2% doses of peracetic acid for 2 weeks do not lead to the alteration of malondialdehyde and enzyme activities. Conclusion This study demonstrated that the enhancement of malondialdehyde could provide an oxidative damage induced by disinfectant peroxidation at 20% and 2% doses at 2 and 4 weeks. The consumption of peroxidation with 20% for 2 weeks and 2% for 4 weeks can cause the increase of malondialdehyde and the decrease of enzyme activities, respectively. PMID:22043353

Corrosion control of carbon steel using inhibitor of banana peel extract in acid diluted solutions

Science.gov (United States)

Komalasari; Utami, S. P.; Fermi, M. I.; Aziz, Y.; Irianti, R. S.

2018-04-01

Issues of corrosion happened in pipes, it was used as fluid transportation in the chemical industry. Corrosion cannot be preventing, however it could be controlled or blocked. Inhibitor addition is one of the method to control the corrosion inside the pipe. Corrosion inhibitors consisted of inorganic and organic compound inhibitors. Organic inhibitor is composed from synthetic and natural material. This study focused to evaluate the inhibition’s efficiency from banana peel to carbon steel in different concentration of inhibitor and immersing time in acid solution variation. The research employed inhibitor concentration of 0 gram/liter, 2 gram/liter, 4 gram/liter and 6 gram/liter, immersed time of carbon steel for 2, 4, 6, 8 and 10 hours. It was immersed in chloride acid solution of 0.5 M and 1.5 M. Carbon Steel AISI 4041 was used as specimen steel. Results were analyzed using corrosion rate evaluation for each specimens and inhibitor efficiencies determination. It was found that the specimen without inhibitor yielded fast corrosion rate in long immersing time and high concentration of HCl. However, the specimens with inhibitor gave lowest corrosion rate which was 78.59% for 6 gram/litre and 10 hours in 0.5 M HCl.

Pain and beyond: fatty acid amides and fatty acid amide hydrolase inhibitors in cardiovascular and metabolic diseases.

Science.gov (United States)

Pillarisetti, Sivaram; Alexander, Christopher W; Khanna, Ish

2009-12-01

Fatty acid amide hydrolase (FAAH) is responsible for the hydrolysis of several important endogenous fatty acid amides (FAAs), including anandamide, oleoylethanolamide and palmitoylethanolamide. Because specific FAAs interact with cannabinoid and vanilloid receptors, they are often referred to as 'endocannabinoids' or 'endovanilloids'. Initial interest in this area, therefore, has focused on developing FAAH inhibitors to augment the actions of FAAs and reduce pain. However, recent literature has shown that these FAAs - through interactions with unique receptors (extracellular and intracellular) - can induce a diverse array of effects that include appetite suppression, modulation of lipid and glucose metabolism, vasodilation, cardiac function and inflammation. This review gives an overview of FAAs and diverse FAAH inhibitors and their potential therapeutic utility in pain and non-pain indications.

Di-n-butylamine as an inhibitor for the corrosion of aluminium alloys in hydrochloric acid solutions

Energy Technology Data Exchange (ETDEWEB)

Unni, V K.V.; Rama Char, T L

1965-01-01

Di-n-butylamine is a satisfactory inhibitor for the corrosion of aluminum-manganese alloy in hydrochloric acid solutions. Polarization studies indicate that the anode polarization is negligible, whereas the cathode polarization is appreciable and is increased by the inhibitor. The Tafel plot holds good in this case. The dissolution of the metal is electrochemical in character; the corrosion process appears to be under cathodic control. The efficiency increases with time, the effect being quite significant up to about 3 hr. It increases with increases in concentration of the inhibitor up to a certain value beyond which it is constant. The values increase with acid concentration up to 1.25 N., and remain practically unchanged thereafter. An acid concentration of 1.25 N. and an inhibitor concentration of 0.5 g per liter of nitrogen can be regarded as the optimum from the viewpoint of efficiency, the value being in the range 57-84%. The efficiency of the inhibitor for the aluminum-manganese alloy is about the same order as for pure aluminum. (10 refs.)

Correlation between hematologic profile and transaminase enzymes with hospitalization duration dengue

Science.gov (United States)

Tinambunan, E.; Suryani; Katu, S.; Halim, R.; Mubin, A. H.; Sahyuddin

2018-03-01

Dengue is an infectious disease that can be found from mild to severe andaffected the clinical spectrum of the disease. Various hematologic profiles and transaminase enzymes are thought to reflect the severity of the disease thus affecting the hospitalization duration. For determining the correlation between hematological profile and transaminase enzyme to the hospitalization duration in dengue patients, an observational design study with the cross-sectional approach on dengue subjects was from 2 hospitals in Makassar. Hemoglobin, leukocyte, thrombocyte, AST, ALT, PT, and APTT were examined for hospitalization duration. There were 65 samples (34 men, 31 women) with the length of stay dengue patients. There was no correlation between the elevated of hematocrit value (p = 0.429), thrombocytopenia (p = 1.000), elevated of AST (p = 0.456) and ALT (p = 0.285) on hospitalization duration. In conclusion, low leukocyte values and APTT prolongation correlate with hospitalization duration but did not correlate significantly with hospitalization duration for elevated hematocrit, thrombocytopenia, elevated AST, and ALT.

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.

Glutamate decarboxylase and. gamma. -aminobutyric acid transaminase activity in brain structures during action of high concentrated sulfide gas on a background of hypo- and hypercalcemia

Energy Technology Data Exchange (ETDEWEB)

Kadyrov, G.K.; Aliyev, A.M.

Activity of the following enzymes was studied on the background of hypo- and hypercalcemia and exposure to high concentration of sulfide gas: glutamate decarboxylase (GDC) and {gamma}-aminobutyric acid transaminase (GABA-T). These enzymes regulate metabolism of GABA. The results showed that a 3.5 hr exposure to sulfide gas at a concentration of 0.3 mg/1 led to significantly increased activity of GDC in cerebral hemispheres, cerebellum and in brain stem. Activity of GABA-T dropped correspondingly. On the background of hypercalcemia induced by im. injection of 10% calcium gluconate (0.6 m1/200 g body weight of experimental rats) the negative effect caused by the exposure to sulfide gas was diminished. Under conditions of hypocalcemia (im. injection of 10 mg/200 g body weight of sodium oxalate), exposure to sulfide gas led to a significantly decreased activity of GDC and GABA-T in the hemispheres and in the brain stem, but in the cerebellum the activity of GDC increased sharply while that of GABA-T decreased correspondingly. 8 refs.

Elevated transaminases as a predictor of coma in a patient with anorexia nervosa: a case report and review of the literature

Directory of Open Access Journals (Sweden)

Yoshida Shuhei

2010-09-01

Full Text Available Abstract Introduction Liver injury is a frequent complication associated with anorexia nervosa, and steatosis of the liver is thought to be the major underlying pathology. However, acute hepatic failure with transaminase levels over 1000 IU/mL and deep coma are very rare complications and the mechanism of pathogenesis is largely unknown. Case presentation A 37-year-old Japanese woman showed features of acute liver failure and hepatic coma which were not associated with hypoglycemia or hyper-ammonemia. Our patient's consciousness was significantly improved with the recovery of liver function and normalization of transaminase levels after administration of nutritional support. Conclusions Our case report demonstrates that transaminase levels had an inverse relationship with the consciousness of our patient, although the pathogenesis of coma remains largely unknown. This indicates that transaminase levels can be one of the key predictors of impending coma in patients with anorexia nervosa. Therefore, frequent monitoring of transaminase levels combined with rigorous treatment of the underlying nutritional deficiency and psychiatric disorder are necessary to prevent this severe complication.

γ-Aminobutyric acid transaminase deficiency impairs central carbon metabolism and leads to cell wall defects during salt stress in Arabidopsis roots.

Science.gov (United States)

Renault, Hugues; El Amrani, Abdelhak; Berger, Adeline; Mouille, Grégory; Soubigou-Taconnat, Ludivine; Bouchereau, Alain; Deleu, Carole

2013-05-01

Environmental constraints challenge cell homeostasis and thus require a tight regulation of metabolic activity. We have previously reported that the γ-aminobutyric acid (GABA) metabolism is crucial for Arabidopsis salt tolerance as revealed by the NaCl hypersensitivity of the GABA transaminase (GABA-T, At3g22200) gaba-t/pop2-1 mutant. In this study, we demonstrate that GABA-T deficiency during salt stress causes root and hypocotyl developmental defects and alterations of cell wall composition. A comparative genome-wide transcriptional analysis revealed that expression levels of genes involved in carbon metabolism, particularly sucrose and starch catabolism, were found to increase upon the loss of GABA-T function under salt stress conditions. Consistent with the altered mutant cell wall composition, a number of cell wall-related genes were also found differentially expressed. A targeted quantitative analysis of primary metabolites revealed that glutamate (GABA precursor) accumulated while succinate (the final product of GABA metabolism) significantly decreased in mutant roots after 1 d of NaCl treatment. Furthermore, sugar concentration was twofold reduced in gaba-t/pop2-1 mutant roots compared with wild type. Together, our results provide strong evidence that GABA metabolism is a major route for succinate production in roots and identify GABA as a major player of central carbon adjustment during salt stress. © 2012 Blackwell Publishing Ltd.

Process engineering tools to guide implementation and scale-up of transaminase cascades

DEFF Research Database (Denmark)

Tufvesson, Pär; Janes, Kresimir; Lima Ramos, Joana

Biocatalysis is gaining ground in the pharmaceutical and fine chemical industry as a selective and potentially green technology to help synthesize industrially interesting products. In particular in the last decade the application of transaminases (E.C. 2.6.1.X ) has gained particular attention...... properties and values. A major challenge in the transaminase catalysed synthesis of chiral amines is the unfavourable equilibrium position [1]. There are several solutions to such equilibrium problems, including the use of in-situ product removal (ISPR) and cascade reactions to degrade or recycle the co......-product formed. Such techniques, especially those using cascades can be a great tool to overcome the thermodynamic hurdle, but also present some new challenges with respect to compatibility of reaction conditions, recycling of co-factors and last but not least, the added cost of the cascade system components [2...

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.

Explaining Operational Instability of Amine Transaminases : Substrate-Induced Inactivation Mechanism and Influence of Quaternary Structure on Enzyme-Cofactor Intermediate Stability

NARCIS (Netherlands)

Borner, Tim; Ramisch, Sebastian; Reddem, Eswar R.; Bartsch, Sebastian; Vogel, Andreas; Thunnissen, Andy-Mark W. H.; Adlercreutz, Patrick; Grey, Carl

The insufficient operational stability of amine transaminases (ATA) constitutes a limiting factor for high productivity in chiral amine synthesis. In this work, we investigated the operational stability of a tetrameric ATA with 92% sequence identity to a Pseudomonas sp. transaminase and compared it

The discovery of glycine and related amino acid-based factor Xa inhibitors

Energy Technology Data Exchange (ETDEWEB)

Kohrt, Jeffrey T.; Filipski, Kevin J.; Cody, Wayne L.; Bigge, Christopher F.; La, Frances; Welch, Kathleen; Dahring, Tawny; Bryant, John W.; Leonard, Daniele; Bolton, Gary; Narasimhan, Lakshmi; Zhang, Erli; Peterson, J. Thomas; Haarer, Staci; Sahasrabudhe, Vaishali; Janiczek, Nancy; Desiraju, Shrilakshmi; Hena, Mostofa; Fiakpui, Charles; Saraswat, Neerja; Sharma, Raman; Sun, Shaoyi; Maiti, Samarendra N.; Leadley, Robert; Edmunds, Jeremy J. (Naeja); (Pfizer)

2010-12-03

Herein, we report on the identification of three potent glycine and related amino acid-based series of FXa inhibitors containing a neutral P1 chlorophenyl pharmacophore. A X-ray crystal structure has shown that constrained glycine derivatives with optimized N-substitution can greatly increase hydrophobic interactions in the FXa active site. Also, the substitution of a pyridone ring for a phenylsulfone ring in the P4 sidechain resulted in an inhibitor with enhanced oral bioavailability.

Identification of Novel Functional Inhibitors of Acid Sphingomyelinase

DEFF Research Database (Denmark)

Kornhuber, Johannes; Muehlbacher, Markus; Trapp, Stefan

2011-01-01

of ASM, such as Alzheimer's disease, major depression, radiation-and chemotherapy-induced apoptosis and endotoxic shock syndrome. Residual activity of ASM measured in the presence of 10 mu M drug concentration shows a bimodal distribution; thus the tested drugs can be classified into two groups......We describe a hitherto unknown feature for 27 small drug-like molecules, namely functional inhibition of acid sphingomyelinase (ASM). These entities named FIASMAs (Functional Inhibitors of Acid SphingoMyelinAse), therefore, can be potentially used to treat diseases associated with enhanced activity...... with lower and higher inhibitory activity. All FIASMAs share distinct physicochemical properties in showing lipophilic and weakly basic properties. Hierarchical clustering of Tanimoto coefficients revealed that FIASMAs occur among drugs of various chemical scaffolds. Moreover, FIASMAs more frequently violate...

Room-temperature solid phase ionic liquid (RTSPIL) coated Ω-transaminases: Development and application in organic solvents

DEFF Research Database (Denmark)

Grabner, B.; Nazario, M. A.; Gundersen, M. T.

2018-01-01

ω-Transaminases ATA-40, ATA-47 and ATA-82P were coated with room-temperature solid phase ionic liquids (RTSPILs) by means of three methods, melt coating, precipitation coating, and co‐lyophilization, and showed increased stability in all of the five tested organic solvents. Co‐lyophilization and ......ω-Transaminases ATA-40, ATA-47 and ATA-82P were coated with room-temperature solid phase ionic liquids (RTSPILs) by means of three methods, melt coating, precipitation coating, and co‐lyophilization, and showed increased stability in all of the five tested organic solvents. Co...

Fatty acid synthase inhibitors isolated from Punica granatum L

International Nuclear Information System (INIS)

Jiang, He-Zhong; Ma, Qing-Yun; Liang, Wen-Juan; Huang, Sheng-Zhuo; Dai, Hao-Fu; Wang, Peng-Cheng; Zhao, You-Xing; Fan, Hui-Jin; Ma, Xiao-Feng

2012-01-01

The aim of this work is the isolation of fatty acid synthase (FAS) inhibitors from the ethyl acetate extracts of fruit peels of Punica granatum L. Bioassay-guided chemical investigation of the fruit peels resulted in the isolation of seventeen compounds mainly including triterpenoids and phenolic compounds, from which one new oleanane-type triterpene (punicaone) along with fourteen known compounds were isolated for the first time from this plant. Seven isolates were evaluated for inhibitory activities of FAS and two compounds showed to be active. Particularly, flavogallonic acid exhibited strong FAS inhibitory activity with IC 50 value of 10.3 μmol L -1 . (author)

Fatty acid synthase inhibitors isolated from Punica granatum L

Energy Technology Data Exchange (ETDEWEB)

Jiang, He-Zhong [School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, (China); Ma, Qing-Yun; Liang, Wen-Juan; Huang, Sheng-Zhuo; Dai, Hao-Fu; Wang, Peng-Cheng; Zhao, You-Xing, E-mail: zhaoyx1011@163.com [Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou (China); Fan, Hui-Jin; Ma, Xiao-Feng, E-mail: maxiaofeng@gucas.ac.cn [College of Life Sciences, Graduate University of Chinese Academy of Sciences, Beijing (China)

2012-05-15

The aim of this work is the isolation of fatty acid synthase (FAS) inhibitors from the ethyl acetate extracts of fruit peels of Punica granatum L. Bioassay-guided chemical investigation of the fruit peels resulted in the isolation of seventeen compounds mainly including triterpenoids and phenolic compounds, from which one new oleanane-type triterpene (punicaone) along with fourteen known compounds were isolated for the first time from this plant. Seven isolates were evaluated for inhibitory activities of FAS and two compounds showed to be active. Particularly, flavogallonic acid exhibited strong FAS inhibitory activity with IC{sub 50} value of 10.3 {mu}mol L{sup -1}. (author)

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

Influence of containing of asphaltenes and naphthenic acids over organic deposition inhibitor performance

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Geiza E.; Mansur, Claudia R.E.; Pires, Renata V.; Passos, Leonardo B.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas; Alvares, Dellyo R.S.; Gonzalez, Gaspar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2004-07-01

Organic deposition is a serious problem confronted by the petroleum industry in Brazil and worldwide. Among the main petroleum components that may cause deposition problems are waxes and asphaltenes. This work aims at evaluating the influence of petroleum fractions (asphaltenes and naphthenic acids) on the organic deposition phenomenon as well as on organic deposition inhibitors performance. The influence of the organic fractions was evaluated by their ability to change wax crystals, to lower the pour point and to alter the initial wax appearance temperature. The efficiency of the additives was tested by pour point measurements. The results show that asphaltenes seem to act as organic deposition inhibitors, while naphthenic acids do not significantly change the system. Moreover, employing both of them produces no synergic effect. Among polymeric inhibitors, all of the chemically modified EVA copolymer presented better results than the non-modified commercial EVA copolymer. The best result was observed for EVA28C{sub 16}. (author)

Termoativação da transaminase glutâmico oxaloacética

Directory of Open Access Journals (Sweden)

Hélion Póvoa Júnior

1973-01-01

Full Text Available Estudou-se a atividade da transaminase glutâmico oxaloacética (TGO em diferentes tecidos (fígado, músculo, rim, pulmão, baço e soro sanguíneo de ratos e de soro humano. verificou-se que a atividade da enzima proveniente de qualquer um destes tecidos é aumentada cerca de tr~es vezes quando a incubação se faz a 60ºC, ao invés de 37ºC. São feitas considerações acerca da importância deste fato.Glutamic Oxalacetic transaminase is thermoativated. Its optimum of catalytical activity is at 60ºC. At this temperature, colour is approximately three times more intense than at 37ºC, temperature usually utilized for determination of enzyme activity. This phenomenon is observed in human blood serum and several rat tissues (liver, heart, striated muscle, spleen, lung, kidney and blood serum.

Raltegravir: first in class HIV integrase inhibitor

Directory of Open Access Journals (Sweden)

Zelalem Temesgen

2008-06-01

Full Text Available Zelalem Temesgen1, Dawd S Siraj21Mayo Clinic, Rochester, MN, USA; 2East Carolina University Greenville, NC, USAAbstract: On October 16, 2007, the US Food and Drug Administration (FDA approved raltegravir for treatment of human immunodeficiency virus (HIV-1 infection in combination with other antiretroviral agents in treatment-experienced adult patients who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents. Raltegravir is first in a novel class of antiretroviral drugs known as integrase inhibitors. It has demonstrated potent anti HIV activity in both antiretroviral treatment-naïve and experienced patients. The most common adverse events reported with raltegravir during phase 2 and 3 clinical trials were diarrhea, nausea, and headache. Laboratory abnormalities include mild elevations in liver transaminases and creatine phosphokinase.Keywords: raltegravir, HIV, antiretroviral agents, integrase inhibitors

and alanine (EC. 2.6.1.2) transaminases, and alkaline phosphatase

African Journals Online (AJOL)

The activities of aspartate (E.C. 2.6.1.1) and alanine (E.C. 2.6.1.2) transaminases (AST and ALT, respectively), and alkaline phosphatase (ALP) (E.C. 3.1.3.1) were determined in erythrocytes obtained from 20 HbAA, 15 HbAS and 12 HbSS human subjects. The results showed that the three enzymes had different levels of ...

Trivaric acid, a new inhibitor of PTP1b with potent beneficial effect on diabetes.

Science.gov (United States)

Sun, Wenlong; Zhang, Bowei; Zheng, Haizhou; Zhuang, Chunlin; Li, Xia; Lu, Xinhua; Quan, Chunshan; Dong, Yuesheng; Zheng, Zhihui; Xiu, Zhilong

2017-01-15

To screen a potential PTP1b inhibitor from the microbial origin-based compound library and to investigate the potential anti-diabetic effects of the inhibitor in vivo and determine its primary anti-diabetic mechanism in vitro and in silico. PTP1b inhibitory activity was measured using recombination protein as the enzyme and p-NPP as the substrate. The binding of the inhibitor to PTP1b was analysed by docking in silico and confirmed by ITC experiments. The intracellular signalling pathway was detected by Western blot analysis in HepG2 cells. The anti-diabetic effects were evaluated using a diabetic mice model in vivo. Among 545 microbial origin-based pure compounds tested, trivaric acid, a tridepside, was selected as a PTP1B inhibitor exhibiting strong inhibitory activity with an IC 50 of 173nM. Docking and ITC studies showed that trivaric acid was able to spontaneously bind to PTP1b and may inhibit PTP1b by blocking the catalytic domain of the phosphatase. Trivaric acid also enhanced the ability of insulin to stimulate the IR/IRS/Akt/GLUT2 pathway and increase the glucose consumption in HepG2 cells. In diabetic mice, trivaric acid that had been encapsulated into Eudrgit L100-5.5 showed significant anti-diabetic effects, improving insulin resistance, leptin resistance and lipid profile and weight control at doses of 5mg/kg and 50mg/kg. Trivaric acid is a potential lead compound in the search for anti-diabetic agents targeting PTP1b. Copyright © 2016 Elsevier Inc. All rights reserved.

Adsorptive detoxification of fermentation inhibitors in acid pretreated liquor using functionalized polymer designed by molecular simulation.

Science.gov (United States)

Devendra, Leena P; Pandey, Ashok

2017-11-01

Acid pretreatment is the most common method employed in the lignocellulosic biorefinery leading to the separation of pentose and hexose sugar. The liquor obtained after pretreatment (acid pretreatment liquor or APL) needs to be detoxified prior to fermentation. The aim of this study was to design functional groups on a polymer matrix which are selective in their interaction to inhibitors with little or no specificity to sugars. Molecular modeling was used as a tool to design a suitable adsorbent for selective adsorption of inhibitors from a complex mixture of APL. Phenyl glycine-p-sulfonic acid loaded on chloromethylated polystyrene polymer was designed as an adsorbent for selective interaction with inhibitors. Experimental verification of the selectivity was successfully achieved. The current study provides insights on the adsorptive separation processes at the molecular level by design of specific adsorbent which can be tailor made for the better selectivity of the desired component.

Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing-induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors.

Science.gov (United States)

Kawamura, O; Shimoyama, Y; Hosaka, H; Kuribayashi, S; Maeda, M; Nagoshi, A; Zai, H; Kusano, M

2011-05-01

Gastro-esophageal reflux disease (GERD)-related chronic cough (CC) may have multifactorial causes. To clarify the characteristics of esophagopharyngeal reflux (EPR) events in CC patients whose cough was apparently influenced by gastro-esophageal reflux (GER), we studied patients with CC clearly responding to full-dose proton pump inhibitor (PPI) therapy (CC patients). Ten CC patients, 10 GERD patients, and 10 healthy controls underwent 24-h ambulatory pharyngo-esophageal impedance and pH monitoring. Weakly acidic reflux was defined as a decrease of pH by >1 unit with a nadir pH >4. In six CC patients, monitoring was repeated after 8 weeks of PPI therapy. The number of each EPR event and the symptom association probability (SAP) were calculated. Symptoms were evaluated by a validated GERD symptom questionnaire. Weakly acidic gas EPR and swallowing-induced acidic/weakly acidic EPR only occurred in CC patients, and the numbers of such events was significantly higher in the CC group than in the other two groups (P pump inhibitor therapy abolished swallowing-induced acidic/weakly acidic EPR, reduced weakly acidic gas EPR, and improved symptoms (all P gas EPR and swallowing-induced acidic/weakly acidic EPR. A direct effect of acidic mist or liquid refluxing into the pharynx may contribute to chronic cough, while cough may also arise indirectly from reflux via a vago-vagal reflex in some patients. © 2011 Blackwell Publishing Ltd.

Development of Poly Lactic/Glycolic Acid (PLGA Microspheres for Controlled Release of Rho-Associated Kinase Inhibitor

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Sho Koda

2017-01-01

Full Text Available Purpose. The purpose of this study was to investigate the feasibility of poly lactic/glycolic acid (PLGA as a drug delivery carrier of Rho kinase (ROCK inhibitor for the treatment of corneal endothelial disease. Method. ROCK inhibitor Y-27632 and PLGA were dissolved in water with or without gelatin (W1, and a double emulsion [(W1/O/W2] was formed with dichloromethane (O and polyvinyl alcohol (W2. Drug release curve was obtained by evaluating the released Y-27632 by using high performance liquid chromatography. PLGA was injected into the anterior chamber or subconjunctiva in rabbit eyes, and ocular complication was evaluated by slitlamp microscope and histological analysis. Results. Y-27632 incorporated PLGA microspheres with different molecular weights, and different composition ratios of lactic acid and glycolic acid were fabricated. A high molecular weight and low content of glycolic acid produced a slower and longer release. The Y-27632 released from PLGA microspheres significantly promoted the cell proliferation of cultured corneal endothelial cells. The injection of PLGA did not induce any evident eye complication. Conclusions. ROCK inhibitor-incorporated PLGA microspheres were fabricated, and the microspheres achieved the sustained release of ROCK inhibitor over 7–10 days in vitro. Our data should encourage researchers to use PLGA microspheres for treating corneal endothelial diseases.

Study on tea leaves extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

Science.gov (United States)

Hamdan, A. B.; Suryanto; Haider, F. I.

2018-01-01

Corrosion inhibitor from extraction of plant has been considered as the most preferable and most chosen technique to prevent corrosion of metal in acidic medium because of the environmental friendly factor. In this study, black tea leaves extraction was tested as corrosion inhibitor for mild steel in 0.1M of hydrochloric acid (HCl) with the absence and presence of corrosion inhibitor. The efficiency and effectiveness of black tea as corrosion inhibitor was tested by using corrosion weight loss measurement experiment was carried out with varies parameters which with different concentration of black tea extract solution. The extraction of black tea solution was done by using aqueous solvent method. The FT-IR result shows that black tea extract containing compounds such as catechin, caffeine and tannins that act as anti-corrosive reagents and responsible to enhance the effectiveness of black tea extract as corrosion inhibitor by forming the hydrophobic thin film through absorption process. As a result of weight loss measurement, it shows that loss in weight of mild steel reduces as the concentration of inhibitor increases. The surface analysis was done on the mild steel samples by using SEM.

Applying Enzymatic Cascades for ISCPR in ω-transaminase Systems

DEFF Research Database (Denmark)

Janes, Kresimir; Woodley, John; Tufvesson, Pär

, esterases, ketoreductases and proteases and many more emerging biocatalysts such are monoamine oxidases, transaminases and P450 monooxygenases to name a few. The focus of this thesis is the biocatalytic synthesis of small molecule pharmaceuticals (Mw... in an industrial process context have thus not been considered properly. In this research lactate dehydrogenase (LDH) (E.C. 1.1.1.27), alanine dehydrogenase (E.C. 1.4.1.1) (AlaDH) and yeast alcohol dehydrogenase (E.C. 1.1.1.1) (YADH) have been researched as co-product degrading enzymes and glucose dehydrogenase...

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.

Fusicoccin-induced catalase inhibitor is produced independently of H+-ATPase activation and behaves as an organic acid.

Science.gov (United States)

Beffagna, Nicoletta; Riva, Marzia Alessandra

2011-06-01

The phytotoxin fusicoccin (FC) was found to induce an increase in apoplastic H₂O₂ content in Arabidopsis thaliana cells, apparently linked to the presence of an as yet unidentified catalase inhibitor detectable even in the external medium of FC-treated cells. This study, aimed to further characterize the inhibitor's features, shows that (1) FC-induced H₂O₂ accumulation increases as a function of FC concentration and correlates to the amount of inhibitor released at apoplastic level. The pattern of H+ efflux, conversely, does not fit with that of these two parameters, suggesting that neither the production nor the release of the catalase inhibitor is linked to the main role of FC in activating the plasma membrane (PM) H+-ATPase; (2) treatment with 10 µM erythrosine B (EB) early and totally inhibits net H+ and K+ fluxes across the PM, indicative of the H+ pump activity; nevertheless, also in these conditions a huge FC-induced H₂O₂ accumulation occurs, confirming that this effect is not related to the FC-induced PM H+-ATPase activation; (3) the inhibitor's release increases with time in all conditions tested and is markedly affected by extracellular pH (a higher pH value being associated to a larger efflux), in agreement with a weak acid release; and (4) the inhibitor can be almost completely recovered in a CH₂C₂-soluble fraction extracted from the incubation medium by sequential acid-base partitioning which contains nearly all of the organic acids released. These final results strongly suggest that the metabolite responsible for the FC-induced catalase inhibition belongs to the organic acid class. Copyright © Physiologia Plantarum 2011.

Glycogenic hepatopathy is an under-recognised cause of hepatomegaly and elevated liver transaminases in type 1 diabetes mellitus.

Science.gov (United States)

Irani, N R; Venugopal, K; Kontorinis, N; Lee, M; Sinniah, R; Bates, T R

2015-07-01

Glycogenic hepatopathy (GH) is an under-recognised complication of type 1 diabetes mellitus (T1DM) not controlled to target resulting in hepatomegaly and elevated liver transaminases. We report the case of a 19-year-old man with T1DM not controlled to target who presented with abdominal pain, hepatomegaly and deranged liver transaminases. He was subsequently diagnosed with GH on liver biopsy, with the mainstay of treatment being reduction in caloric intake and insulin. © 2015 Royal Australasian College of Physicians.

[Tranexamic acid as first-line emergency treatment for episodes of bradykinin-mediated angioedema induced by ACE inhibitors].

Science.gov (United States)

Beauchêne, C; Martins-Héricher, J; Denis, D; Martin, L; Maillard, H

2018-05-04

Episodes of acquired bradykinin-mediated angioedema due to angiotensin-converting enzyme (ACE) inhibitors may result in fatal outcomes. There is no consensus regarding emergency pharmacological management of these episodes. Treatment options include icatibant and C1INH concentrate. Tranexamic acid is administered for moderate episodes. Its efficacy in the treatment of ACE inhibitor-induced episodes of angioedema is not established. The aim of this retrospective study is to assess the benefits of emergency tranexamic acid administration in the management of ACE inhibitor-induced episodes of angioedema. Retrospective analysis of the medical files of patients who consulted between 2010 and 2016 in two French tertiary care hospitals for a bradykinic angioedema attributed to an ACE treatment. All of them had received tranexamic acid as a first line treatment. Thirty three patients who had experienced severe episode of angioedema were included. Twenty seven patients showed significant improvement when treated with tranexamic acid alone. The six remaining patients were treated with icatibant (5/33) or C1INH concentrate (1/33), due to partial improvement after tranexamic acid therapy. None of the patients were intubated, no fatalities were recorded and no side effects were reported. Tranexamic acid is an easily accessible and affordable therapy that may provide effective treatment for ACE inhibitor-induced episodes of angioedema. It may help while waiting for a more specific treatment (icatibant and C1INH concentrate) that is at times unavailable in emergency departments. Copyright © 2018 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Amino-acid sequences of trypsin inhibitors from watermelon (Citrullus vulgaris) and red bryony (Bryonia dioica) seeds.

Science.gov (United States)

Otlewski, J; Whatley, H; Polanowski, A; Wilusz, T

1987-11-01

The amino-acid sequences of two trypsin inhibitors isolated from red bryony (Bryonia dioica) and watermelon (Citrullus vulgaris) seeds are reported. Both species represent different genera of the Cucurbitaceae family, which have not been previously investigated as a source of proteinase inhibitors. The sequences are unique but are very similar to those of other proteinase inhibitors which have been isolated from squash seeds. Based on structural homology we assume that the Arg5-Ile6 peptide bond represents the reactive site bond of both inhibitors.

Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

Energy Technology Data Exchange (ETDEWEB)

Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C., E-mail: cdirusso2@unl.edu

2015-09-25

The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC{sub 50} 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC{sub 50} 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of {sup 13}C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata.

Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

International Nuclear Information System (INIS)

Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C.

2015-01-01

The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC 50 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC 50 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of 13 C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata

Transamination of cysteine-sulfinic acid by extracts of oat leaves

International Nuclear Information System (INIS)

Perez-Milan, H.; Schuack, J.; Fromageot, P.

1960-01-01

An aqueous extract of oat leaves catalyses a transamination between cysteine-sulfinic acid and α-ketoglutaric acid. Under the conditions utilized pyruvic acid is not an acceptor of the amino group. Neither cysteic nor aspartic acid are a substrate for the transaminase of cysteine-sulfinic acid. Reprint of a paper published in Biochimica et Biophysica Acta, Vol. 36, 1959, p. 73-83 [fr

Functional loss of GABA transaminase (GABA-T) expressed early leaf senescence under various stress conditions in Arabidopsis thaliana

OpenAIRE

Jalil, Syed Uzma; Ahmad, Iqbal; Ansari, Mohammad Israil

2017-01-01

GABA-transaminase (GABA-T) involved in carbon and nitrogen metabolism during the plant development process via GABA shunt and GABA-T mutant, which is defective in GABA catabolism, is ideal model to examine the role of GABA-T in plant development and leaf senescence of plant. We have characterized GABA transaminase knock out mutant pop2-1 that is transition and pop2-3 which is T-DNA insertion mutant of Arabidopsis thaliana during various stress conditions.The GABA-T knockout mutant plants disp...

Valproic Acid as a Potential Inhibitor of Plasmodium falciparum Histone Deacetylase 1 (PfHDAC1: An in Silico Approach

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Mohamed A. Abdallah Elbadawi

2015-02-01

Full Text Available A new Plasmodium falciparum histone deacetylase1 (PfHDAC1 homology model was built based on the highest sequence identity available template human histone deacetylase 2 structure. The generated model was carefully evaluated for stereochemical accuracy, folding correctness and overall structure quality. All evaluations were acceptable and consistent. Docking a group of hydroxamic acid histone deacetylase inhibitors and valproic acid has shown binding poses that agree well with inhibitor-bound histone deacetylase-solved structural interactions. Docking affinity dG scores were in agreement with available experimental binding affinities. Further, enzyme-ligand complex stability and reliability were investigated by running 5-nanosecond molecular dynamics simulations. Thorough analysis of the simulation trajectories has shown that enzyme-ligand complexes were stable during the simulation period. Interestingly, the calculated theoretical binding energies of the docked hydroxamic acid inhibitors have shown that the model can discriminate between strong and weaker inhibitors and agrees well with the experimental affinities reported in the literature. The model and the docking methodology can be used in screening virtual libraries for PfHDAC1 inhibitors, since the docking scores have ranked ligands in accordance with experimental binding affinities. Valproic acid calculated theoretical binding energy suggests that it may inhibit PfHDAC1.

Dideoxynucleoside HIV reverse transcriptase inhibitors and drug-related hepatotoxicity: a case report

Directory of Open Access Journals (Sweden)

Lapadula Giuseppe

2007-05-01

Full Text Available Abstract This report regards the case of a 43 year-old HIV-positive woman who developed an episode of serious transaminase elevation during stavudine-including antiretroviral therapy. Diagnostic assessment ruled out hepatitis virus co-infection, alcohol abuse besides other possible causes of liver damage. No signs of lactic acidosis were present. Liver biopsy showed portal inflammatory infiltrate, spotty necrosis, vacuoles of macro- and micro-vesicular steatosis, acidophil and foamy hepatocytes degeneration with organelles clumping, poorly formed Mallory bodies and neutrophil granulocytes attraction (satellitosis. A dramatic improvement in liver function tests occurred when stavudine was discontinued and a new antiretroviral regimen with different nucleoside reverse transcriptase inhibitors was used. The importance of considering hepatotoxicity as an adverse event of HAART including stavudine, even in absence of other signs of mitochondrial toxicity should therefore be underlined. Liver biopsy may provide further important information regarding patients with severe transaminase elevation, for a better understanding of the etiology of liver damage.

Basic studies on I-123-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) for myocardial functional diagnosis. Effect of beta-oxidation inhibitor

Energy Technology Data Exchange (ETDEWEB)

Fujibayashi, Yasuhisa; Yonekura, Yoshiharu; Yamamoto, Kazutaka; Tamaki, Nagara; Konishi, Junji; Kawai, Keiichi; Yokoyama, Akira; Torizuka, Kanji.

1988-10-01

To clarify the availability of I-123-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) as myocardial metabolism diagnostic agent, the effect of beta-oxidation inhibitor on BMIPP metabolic behavior was studied in relation to lipid pool. As for inhibitor, tetradecylglycidic acid (TDGA), mitochondrial carnitine acyltransferase I inhibitor, was used. Both in TDGA pre-treated and control rats, BMIPP was found in TG fraction of the heart, showing no inhibitory effect of TDGA on TG-synthesis. In TDGA pre-treated rats, BMIPP accumulation in the heart was greatly increased together with triglyceride (TG) content; free fatty acid and diglyceride content had no remarkable change. So, TG synthesis, which acts as substrate-storage, can be evaluated as an index reflecting the changes of fatty acid metabolism. BMIPP is a plausible radiopharmaceutical for myocardial fatty acid metabolism study, as a substrate of triglyceride synthesis.

Aristolochic acid and its derivatives as inhibitors of snake venom L-amino acid oxidase.

Science.gov (United States)

Bhattacharjee, Payel; Bera, Indrani; Chakraborty, Subhamoy; Ghoshal, Nanda; Bhattacharyya, Debasish

2017-11-01

Snake venom L-amino acid oxidase (LAAO) exerts toxicity by inducing hemorrhage, pneumorrhagia, pulmonary edema, cardiac edema, liver cell necrosis etc. Being well conserved, inhibitors of the enzyme may be synthesized using the template of the substrate, substrate binding site and features of the catalytic site of the enzyme. Previous findings showed that aristolochic acid (AA), a major constituent of Aristolochia indica, inhibits Russell's viper venom LAAO enzyme activity since, AA interacts with DNA and causes genotoxicity, derivatives of this compound were synthesized by replacing the nitro group to reduce toxicity while retaining the inhibitory potency. The interactions of AA and its derivatives with LAAO were followed by inhibition kinetics and surface plasmon resonance. Similar interactions with DNA were followed by absorption spectroscopy and atomic force microscopy. LAAO-induced cytotoxicity was evaluated by generation of reactive oxygen species (ROS), cell viability assays, confocal and epifluorescence microscopy. The hydroxyl (AA-OH) and chloro (AA-Cl) derivatives acted as inhibitors of LAAO but did not interact with DNA. The derivatives significantly reduced LAAO-induced ROS generation and cytotoxicity in human embryonic kidney (HEK 293) and hepatoma (HepG2) cell lines. Confocal images indicated that AA, AA-OH and AA-Cl interfered with the binding of LAAO to the cell membrane. AA-OH and AA-Cl significantly inhibited LAAO activity and reduced LAAO-induced cytotoxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

A human fatty acid synthase inhibitor binds β-ketoacyl reductase in the keto-substrate site.

Science.gov (United States)

Hardwicke, Mary Ann; Rendina, Alan R; Williams, Shawn P; Moore, Michael L; Wang, Liping; Krueger, Julie A; Plant, Ramona N; Totoritis, Rachel D; Zhang, Guofeng; Briand, Jacques; Burkhart, William A; Brown, Kristin K; Parrish, Cynthia A

2014-09-01

Human fatty acid synthase (hFAS) is a complex, multifunctional enzyme that is solely responsible for the de novo synthesis of long chain fatty acids. hFAS is highly expressed in a number of cancers, with low expression observed in most normal tissues. Although normal tissues tend to obtain fatty acids from the diet, tumor tissues rely on de novo fatty acid synthesis, making hFAS an attractive metabolic target for the treatment of cancer. We describe here the identification of GSK2194069, a potent and specific inhibitor of the β-ketoacyl reductase (KR) activity of hFAS; the characterization of its enzymatic and cellular mechanism of action; and its inhibition of human tumor cell growth. We also present the design of a new protein construct suitable for crystallography, which resulted in what is to our knowledge the first co-crystal structure of the human KR domain and includes a bound inhibitor.

Amino derivatives of glycyrrhetinic acid as potential inhibitors of cholinesterases.

Science.gov (United States)

Schwarz, Stefan; Lucas, Susana Dias; Sommerwerk, Sven; Csuk, René

2014-07-01

The development of remedies against the Alzheimer's disease (AD) is one of the biggest challenges in medicinal chemistry nowadays. Although not completely understood, there are several strategies fighting this disease or at least bringing some relief. During the progress of AD, the level of acetylcholine (ACh) decreases; hence, a therapy using inhibitors should be of some benefit to the patients. Drugs presently used for the treatment of AD inhibit the two ACh controlling enzymes, acetylcholinesterase as well as butyrylcholinesterase; hence, the design of selective inhibitors is called for. Glycyrrhetinic acid seems to be an interesting starting point for the development of selective inhibitors. Although its glycon, glycyrrhetinic acid is known for being an AChE activator, several derivatives, altered in position C-3 and C-30, exhibited remarkable inhibition constants in micro-molar range. Furthermore, five representative compounds were subjected to three more enzyme assays (on carbonic anhydrase II, papain and the lipase from Candida antarctica) to gain information about the selectivity of the compounds in comparison to other enzymes. In addition, photometric sulforhodamine B assays using murine embryonic fibroblasts (NiH 3T3) were performed to study the cytotoxicity of these compounds. Two derivatives, bearing either a 1,3-diaminopropyl or a 1H-benzotriazolyl residue, showed a BChE selective inhibition in the single-digit micro-molar range without being cytotoxic up to 30μM. In silico molecular docking studies on the active sites of AChE and BChE were performed to gain a molecular insight into the mode of action of these compounds and to explain the pronounced selectivity for BChE. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nicotinic acid as a nontoxic corrosion inhibitor for hot dipped Zn and Zn-Al alloy coatings on steels in diluted hydrochloric acid

Energy Technology Data Exchange (ETDEWEB)

Ju Hong [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Li Yan [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China)], E-mail: yanlee@ms.qdio.ac.cn

2007-11-15

The inhibition effect of nicotinic acid for corrosion of hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid was investigated using quantum chemistry analysis, weight loss test, electrochemical measurement, and scanning electronic microscope (SEM) analysis. Quantum chemistry calculation results showed that nicotinic acid possessed planar structure with a number of active centers, and the populations of the Mulliken charge, the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) were found mainly focused around oxygen and nitrogen atoms, and the cyclic of the benzene as well. The results of weight loss test and electrochemical measurement indicated that inhibition efficiency (IE%) increased with inhibitor concentration, and the highest inhibition efficiency was up to 96.7%. The corrosion inhibition of these coatings was discussed in terms of blocking the electrode reaction by adsorption of the molecules at the active centers on the electrode surface. It was found that the adsorption of nicotinic acid on coating surface followed Langmuir adsorption isotherm with single molecular layer, and nicotinic acid adsorbed on the coating surface probably by chemisorption. Nicotinic acid, therefore, can act as a good nontoxic corrosion inhibitor for hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid solution.

Detection of Benzoic Acid by an Amperometric Inhibitor Biosensor Based on Mushroom Tissue Homogenate

Directory of Open Access Journals (Sweden)

Mustafa Kemal Sezgintürk

2005-01-01

Full Text Available An amperometric benzoic acid-sensing inhibitor biosensor was prepared by immobilizing mushroom (Agaricus bisporus tissue homogenate on a Clark-type oxygen electrode. The effects of the quantity of mushroom tissue homogenate, the quantity of gelatin and the effect of the crosslinking agent glutaraldehyde percent on the biosensor were studied. The optimum concentration of phenol used as substrate was 200 μM. The bioanalytical properties of the proposed biosensor, such as dependence of the biosensor response on the pH value and the temperature, were investigated. The biosensor responded linearly to benzoic acid in a concentration range of 25–100 μM. Standard deviation (s.d. was ±0.49 μM for 7 successive determinations at a concentration of 75 μM. The inhibitor biosensor based on mushroom tissue homogenate was applied for the determination of benzoic acid in fizzy lemonade, some fruits and groundwater samples. Results were compared to those obtained using AOAC method, showing a good agreement.

Anticancer actions of lysosomally targeted inhibitor, LCL521, of acid ceramidase.

Science.gov (United States)

Bai, Aiping; Mao, Cungui; Jenkins, Russell W; Szulc, Zdzislaw M; Bielawska, Alicja; Hannun, Yusuf A

2017-01-01

Acid ceramidase, which catalyzes ceramide hydrolysis to sphingosine and free fatty acid mainly in the lysosome, is being recognized as a potential therapeutic target for cancer. B13 is an effective and selective acid ceramidase inhibitor in vitro, but not as effective in cells due to poor access to the lysosomal compartment. In order to achieve targeting of B13 to the lysosome, we designed lysosomotropic N, N-dimethyl glycine (DMG)-conjugated B13 prodrug LCL521 (1,3-di-DMG-B13). Our previous results indicated the efficient delivery of B13 to the lysosome resulted in augmented effects of LCL521 on cellular acid ceramidase as evaluated by effects on substrate/product levels. Our current studies indicate that functionally, this translated into enhanced inhibition of cell proliferation. Moreover, there were greater synergistic effects of LCL521 with either ionizing radiation or Tamoxifen. Taken together, these results clearly indicate that compartmental targeting for the inhibition of acid ceramidase is an efficient and valuable therapeutic strategy.

Genetic manipulation of the γ-aminobutyric acid (GABA) shunt in rice: overexpression of truncated glutamate decarboxylase (GAD2) and knockdown of γ-aminobutyric acid transaminase (GABA-T) lead to sustained and high levels of GABA accumulation in rice kernels.

Science.gov (United States)

Shimajiri, Yasuka; Oonishi, Takayuki; Ozaki, Kae; Kainou, Kumiko; Akama, Kazuhito

2013-06-01

Gamma-aminobutyric acid (GABA) is a non-protein amino acid commonly present in all organisms. Because cellular levels of GABA in plants are mainly regulated by synthesis (glutamate decarboxylase, GAD) and catabolism (GABA-transaminase, GABA-T), we attempted seed-specific manipulation of the GABA shunt to achieve stable GABA accumulation in rice. A truncated GAD2 sequence, one of five GAD genes, controlled by the glutelin (GluB-1) or rice embryo globulin promoters (REG) and GABA-T-based trigger sequences in RNA interference (RNAi) cassettes controlled by one of these promoters as well, was introduced into rice (cv. Koshihikari) to establish stable transgenic lines under herbicide selection using pyriminobac. T₁ and T₂ generations of rice lines displayed high GABA concentrations (2-100 mg/100 g grain). In analyses of two selected lines from the T₃ generation, there was a strong correlation between GABA level and the expression of truncated GAD2, whereas the inhibitory effect of GABA-T expression was relatively weak. In these two lines both with two T-DNA copies, their starch, amylose, and protein levels were slightly lower than non-transformed cv. Koshihikari. Free amino acid analysis of mature kernels of these lines demonstrated elevated levels of GABA (75-350 mg/100 g polished rice) and also high levels of several amino acids, such as Ala, Ser, and Val. Because these lines of seeds could sustain their GABA content after harvest (up to 6 months), the strategy in this study could lead to the accumulation GABA and for these to be sustained in the edible parts. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Amino acid amides of piperic acid (PA) and 4-ethylpiperic acid (EPA) as NorA efflux pump inhibitors of Staphylococcus aureus.

Science.gov (United States)

Wani, Naiem Ahmad; Singh, Samsher; Farooq, Saleem; Shankar, Sudha; Koul, Surrinder; Khan, Inshad Ali; Rai, Rajkishor

2016-09-01

A total of eighteen piperic acid (PA) and 4-ethylpiperic acid (EPA) amides (C1-C18) with α-, β- and γ-amino acids were synthesized, characterized and evaluated for their efflux pump inhibitory activity against ciprofloxacin resistant Staphylococcus aureus. The amides were screened against NorA overexpressing S. aureus SA-1199B and wild type S. aureus SA-1199 using ethidium bromide as NorA efflux pump substrate. EPI C6 was found to be most potent and reduced the MIC of ciprofloxacin by 16 fold followed by C18 which showed 4 fold reduction of MIC. Ethidium bromide efflux inhibition and accumulation assay proved these compounds as NorA inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inhibitors of bacterial N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) and demonstration of in vitro antimicrobial activity.

Science.gov (United States)

Gillner, Danuta; Armoush, Nicola; Holz, Richard C; Becker, Daniel P

2009-11-15

The dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) is a critical bacterial enzyme for the construction of the bacterial cell wall. A screen biased toward compounds containing zinc-binding groups (ZBG's) including thiols, carboxylic acids, boronic acids, phosphonates and hydroxamates has delivered a number of micromolar inhibitors of DapE from Haemophilus influenzae, including the low micromolar inhibitor L-captopril (IC(50)=3.3 microM, K(i)=1.8 microM). In vitro antimicrobial activity was demonstrated for L-captopril against Escherichia coli.

Crystal structures of Leishmania mexicana arginase complexed with α,α-disubstituted boronic amino-acid inhibitors

Energy Technology Data Exchange (ETDEWEB)

Hai, Yang; Christianson, David W.

2016-03-16

Leishmaniaarginase is a potential drug target for the treatment of leishmaniasis because this binuclear manganese metalloenzyme initiatesde novopolyamine biosynthesis by catalyzing the hydrolysis of L-arginine to generate L-ornithine and urea. The product L-ornithine subsequently undergoes decarboxylation to yield putrescine, which in turn is utilized for spermidine biosynthesis. Polyamines such as spermidine are essential for the growth and survival of the parasite, so inhibition of enzymes in the polyamine-biosynthetic pathway comprises an effective strategy for treating parasitic infections. To this end, two X-ray crystal structures ofL. mexicanaarginase complexed with α,α-disubstituted boronic amino-acid inhibitors based on the molecular scaffold of 2-(S)-amino-6-boronohexanoic acid are now reported. Structural comparisons with human and parasitic arginase complexes reveal interesting differences in the binding modes of the additional α-substituents,i.e.the D side chains, of these inhibitors. Subtle differences in the three-dimensional contours of the outer active-site rims among arginases from different species lead to different conformations of the D side chains and thus different inhibitor-affinity trends. The structures suggest that it is possible to maintain affinity while fine-tuning intermolecular interactions of the D side chain of α,α-disubstituted boronic amino-acid inhibitors in the search for isozyme-specific and species-specific arginase inhibitors.

Synergism of antifungal activity between mitochondrial respiration inhibitors and kojic acid.

Science.gov (United States)

Kim, Jong H; Campbell, Bruce C; Chan, Kathleen L; Mahoney, Noreen; Haff, Ronald P

2013-01-25

Co-application of certain types of compounds to conventional antimicrobial drugs can enhance the efficacy of the drugs through a process termed chemosensitization. We show that kojic acid (KA), a natural pyrone, is a potent chemosensitizing agent of complex III inhibitors disrupting the mitochondrial respiratory chain in fungi. Addition of KA greatly lowered the minimum inhibitory concentrations of complex III inhibitors tested against certain filamentous fungi. Efficacy of KA synergism in decreasing order was pyraclostrobin > kresoxim-methyl > antimycin A. KA was also found to be a chemosensitizer of cells to hydrogen peroxide (H₂O₂), tested as a mimic of reactive oxygen species involved in host defense during infection, against several human fungal pathogens and Penicillium strains infecting crops. In comparison, KA-mediated chemosensitization to complex III inhibitors/H₂O₂ was undetectable in other types of fungi, including Aspergillus flavus, A. parasiticus, and P. griseofulvum, among others. Of note, KA was found to function as an antioxidant, but not as an antifungal chemosensitizer in yeasts. In summary, KA could serve as an antifungal chemosensitizer to complex III inhibitors or H₂O₂ against selected human pathogens or Penicillium species. KA-mediated chemosensitization to H₂O₂ seemed specific for filamentous fungi. Thus, results indicate strain- and/or drug-specificity exist during KA chemosensitization.

Proton pump inhibitors reduce the size and acidity of the acid pocket in the stomach.

Science.gov (United States)

Rohof, Wout O; Bennink, Roelof J; Boeckxstaens, Guy E

2014-07-01

The gastric acid pocket is believed to be the reservoir from which acid reflux events originate. Little is known about how changes in position, size, and acidity of the acid pocket contribute to the therapeutic effect of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD). Thirty-six patients with GERD (18 not taking PPIs, 18 taking PPIs; 19 men; age, 55 ± 2.1 y) were analyzed by concurrent high-resolution manometry and pH-impedance monitoring after a standardized meal. The acid pocket was visualized using scintigraphy after intravenous administration of (99m)technetium-pertechnetate. The size of the acid pocket was measured and its position was determined, relative to the diaphragm, using radionuclide markers on a high-resolution manometry catheter. At the end of the study, the acid pocket was aspirated, and its pH level was measured. The number of reflux episodes was comparable between patients on and off PPIs, but the number of acid reflux episodes was reduced significantly in patients on PPIs. In patients on PPIs, the acid pocket was smaller and more frequently located below the diaphragm. The mean pH of the acid pocket was significantly lower in patients not taking PPIs (n = 6) than in those who were (n = 16) (0.9; range, 0.7-1.2 vs 4.0; range, 1.6-5.9; P pH of acid pockets correlated significantly with the lowest pH values measured for refluxate (r = 0.72; P < .01). Based on analyses of acid pockets in patients with GERD, the acid pocket appears to be a reservoir from which reflux occurs when patients are receiving PPIs. PPIs might affect the size, acidity, or position of the acid pocket, which contributes to the efficacy in patients with GERD. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

Solid Obtained by Electrocoagulation of Vinasse, new Inhibitor for Acid Corrosion of Brass

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Elaine Ojeda-Armaignac

2016-07-01

Full Text Available This work is part of research related to obtaining a corrosion inhibitor from vinasse, whose basic advantages is the possibility of using an industrial waste from distilleries ethyl alcohol as raw material in the production of a solid corrosion inhibitor of national production by electrocoagulation, which implies import substitution and cost reductions. The inhibitory action of the solids obtained by electrocoagulation of vinasse was investigated by potentiodynamic polarization techniques and electrochemical impedance spectroscopy. It was found that the efficiencies of inhibition against the brass into the electrolyte solution were very good, behaving as an efficient inhibitor in acid medium. Inhibition efficiency increases with increasing concentration. The maximum inhibition efficiency was of 93,43 % for the concentration of 2 mg / L of vinasse. Thermodynamic parameters were obtained at the study temperature. It was found that the adsorption of inhibitor molecules on the surface of brass obey the Langmuir isotherm, and the values of adsorción free energy of - 23.06 kJ mol-1 show the spontaneity of adsorption and indicate that the inhibitor is strongly adsorbed on the surface of brass, study of potentiodynamic polarization curves confirmed that it is a mixed type inhibitor, with an anode predominance and there is a predominant mechanism of physical adsorption combined with a chemisorption.

L-[4-11C]aspartic acid: enzymatic synthesis, myocardial uptake, and metabolism

International Nuclear Information System (INIS)

Barrio, J.R.; Egbert, J.E.; Henze, E.; Schelbert, H.R.; Baumgartner, F.J.

1982-01-01

Sterile, pyrogen-free L-[4- 11 C]aspartic acid was prepared from 11 CO 2 using phosphoenolpyruvate carboxylase and glutamic/oxaloacetic acid transaminase immobilized on Sepharose supports to determine if it is a useful indicator for in vivo, noninvasive determination of myocardial metabolism. An intracoronary bolus injection of L-[4- 11 C]aspartic acid into dog myocardium showed a triexponential clearance curve with maximal production of 11 CO 2 100 s after injection. Inactivation of myocardial transaminase activity modified the tracer clearance and inhibited the production of 11 CO 2 . Positron-computed tomography imaging showed that the 11 C activities retained in rhesus monkey myocardium are higher than those observed in dog heart after intravenous injection of L-[4- 11 C]aspartic acid. These findings demonstrated the rapid incorporation of the carbon skeleton of L-aspartic acid into the tricarboxylic acid cycle after enzymatic transamination in myocardium and suggested that L-[4- 11 C]aspartic acid could be of value for in vivo, noninvasive assessment of local myocardial metabolism

Immobilisation of ω-transaminase for industrial application: Screening and characterisation of commercial ready to use enzyme carriers

DEFF Research Database (Denmark)

Lima Afonso Neto, Watson; Schürmann, Martin; Panella, Lavinia

2015-01-01

Despite of the advantages that enzyme immobilisation can bring to industrial biocatalysis, its utilisation is still limited to a small number of enzymes and processes. Transaminase catalysed processes are a good example where immobilisation can be of major importance and even decisive for economi...... and possibility to store the biocatalyst for more than 70 days (at room temperature) were obtained as result of the immobilisation on the selected supports.......)-selective ω-transaminases. These carriers allowed the re-use of the immobilised enzyme for 8 cycles of 24 h each, under relevant process conditions, corresponding to approximately 250 h of operation, with more than 50% of the initial activity retained. Likewise the stability towards higher temperatures...

Identification of fermentation inhibitors in wood hydrolyzates and removal of inhibitors by ion exchange and liquid-liquid extraction

Science.gov (United States)

Luo, Caidian

1998-12-01

Common methods employed in the ethanol production from biomass consist of chemical or enzymatic degradation of biomass into sugars and then fermentation of sugars into ethanol or other chemicals. However, some degradation products severely inhibit the fermentation processes and substantially reduce the efficiency of ethanol production. How to remove inhibitors from the reaction product mixture and increase the production efficiency are critical in the commercialization of any processes of energy from biomass. The present study has investigated anion exchange and liquid-liquid extraction as potential methods for inhibitor removal. An analytical method has been developed to identify the fermentation inhibitors in a hydrolyzate. The majority of inhibitors present in hybrid poplar hydrolyzate have positively been identified. Ion exchange with weak basic Dowex-MWA-1 resin has been proved to be an effective mean to remove fermentation inhibitors from hybrid poplar hydrolyzate and significantly increase the fermentation productivity. Extraction with n-butanol might be a preferred way to remove inhibitors from wood hydrolyzates and improve the fermentability of sugars in the hydrolyzates. n-Butanol also removes some glucose, mannose and xylose from the hydrolyzate. Inhibitor identification reveals that lignin and sugar degradation compounds including both aromatic and aliphatic aldehydes and carboxylic acids formed in hydrolysis, plus fatty acids and other components from wood extractives are major fermentation inhibitors in Sacchromyces cerevisiae fermentation. There are 35 components identified as fermentation inhibitors. Among them, 4-hydroxy benzoic acid, 3,4-dihydroxy benzoic acid, syringic acid, syringaldehyde, and ferulic acid are among the most abundant aromatic inhibitors in hybrid poplar hydrolyzate. The conversion of aldehyde groups into carboxylic acid groups in the nitric acid catalyzed hydrolysis reduces the toxicity of the hydrolyzate. A wide spectrum of

Physiological studies on the effect of a phosphodiesterase inhibitor on the blood obtained from hypothyroid rats

International Nuclear Information System (INIS)

Abdel-Ghany, I.Y.

1997-01-01

In the present study 300 male albino rats (100-120 g) were used. The search was planned to evaluate the biochemical effects of the therapeutic drug (pentoxifylline) in combination with thyroxine on the hypothyroid mammals. The biochemical determinations were serum: Tri-iodothyronine (T-3), thyroxine (T-4), Glucose, total protein, urea, creatinine, along with the enzymatic activities of : alkaline phosphatase (ALP), lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT). The study included also glycogen, lactic acid, pyruvic acid, along with the enzymatic activities of : LDH, GOT and GPT in liver tissue homogenate. The data obtained, revealed significant alterations in assayed parameters reflecting disturbance in the metabolism due to hypothyroid state. Treatment of rats with thyroxine and / or pentoxifylline revealed significant amelioration in most of the tested parameters indicating the beneficial effect of these drugs. 17 tabs.,17 figs.,123 refs

Isolated etioplasts as test system for inhibitors of fatty acid biosynthesis

International Nuclear Information System (INIS)

Lichtenthaler, H.K.; Kobek, K.

1989-01-01

Isolated intact chloroplasts of mono- and dicotyledonous plants possess the capacity for de novo fatty acid biosynthesis, starting from 14 C-acetate. These can be taken as test system for herbicides affecting fatty acid biosynthesis as shown earlier in our laboratory. The incorporation rates of acetate into the total fatty acids depend on the photosynthetic cofactors ATP and NADPH and amount in the light to 33 kBq (oat) and 39 kBq (pea) per mg chlorophyll x h, whereas in the dark only ca. 10% of these rates are obtained. In order to establish a test system, which is fully independent of light, we isolated and characterized etioplast fractions from oat and pea seedlings with a very high capacity of de novo fatty acid biosynthesis (500 and 400 kBq per mg carotenoids in a 20 min period). This activity was blocked by herbicides such as cycloxydim, sethoxydim and diclofop in a dose-dependent manner. This new test system has the great advantage that one can verify whether inhibitors of photosynthesis affect fatty acid biosynthesis

Anticancer actions of lysosomally targeted inhibitor, LCL521, of acid ceramidase.

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Aiping Bai

Full Text Available Acid ceramidase, which catalyzes ceramide hydrolysis to sphingosine and free fatty acid mainly in the lysosome, is being recognized as a potential therapeutic target for cancer. B13 is an effective and selective acid ceramidase inhibitor in vitro, but not as effective in cells due to poor access to the lysosomal compartment. In order to achieve targeting of B13 to the lysosome, we designed lysosomotropic N, N-dimethyl glycine (DMG-conjugated B13 prodrug LCL521 (1,3-di-DMG-B13. Our previous results indicated the efficient delivery of B13 to the lysosome resulted in augmented effects of LCL521 on cellular acid ceramidase as evaluated by effects on substrate/product levels. Our current studies indicate that functionally, this translated into enhanced inhibition of cell proliferation. Moreover, there were greater synergistic effects of LCL521 with either ionizing radiation or Tamoxifen. Taken together, these results clearly indicate that compartmental targeting for the inhibition of acid ceramidase is an efficient and valuable therapeutic strategy.

Polyaspartic acid as a corrosion inhibitor for WE43 magnesium alloy

OpenAIRE

Lihui Yang; Yantao Li; Bei Qian; Baorong Hou

2015-01-01

The inhibition behavior of polyaspartic acid (PASP) as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.% NaCl solution by means for EIS measurement, potentiodynamic polarization curve, and scanning electron microscopy. The results show that PASP can inhibit the corrosion of WE43 magnesium alloy. The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study.

Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

International Nuclear Information System (INIS)

Becker, Jan C.; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

2006-01-01

Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection

Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Becker, Jan C [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Grosser, Nina [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Waltke, Christian [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Schulz, Stephanie [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Erdmann, Kati [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Domschke, Wolfram [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Schroeder, Henning [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Pohle, Thorsten [Department of Medicine B, University of Muenster, 48149 Muenster (Germany)

2006-07-07

Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

Effect of Schiff's Bases as Corrosion Inhibitors on Mild Steel in Sulphuric Acid

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R. K. Upadhyay

2007-01-01

Full Text Available Mass loss and thermometric methods have been used to study the corrosion inhibitory effect of synthesised Schiff's bases viz. N-(furfurilidine – 4- methoxy aniline (SB1, N-(furfurilidine – 4- methylaniline (SB2, N-(salicylidine – 4- methoxy aniline (SB3, N-(cinnamalidine – 4 –methoxy aniline (SB4 and N-(cinnamalidine - 2-methylaniline (SB5 on mild steel in sulphuric acid solutions. Results show that both methods have good agreement with each other and inhibition efficiency depends upon the concentration of inhibitor as well as that of acid. Maximum inhibition efficiency is shown at highest concentration of Schiff's bases at the highest strength of acid.

Synergism of Antifungal Activity between Mitochondrial Respiration Inhibitors and Kojic Acid

Directory of Open Access Journals (Sweden)

Ronald P. Haff

2013-01-01

Full Text Available Co-application of certain types of compounds to conventional antimicrobial drugs can enhance the efficacy of the drugs through a process termed chemosensitization. We show that kojic acid (KA, a natural pyrone, is a potent chemosensitizing agent of complex III inhibitors disrupting the mitochondrial respiratory chain in fungi. Addition of KA greatly lowered the minimum inhibitory concentrations of complex III inhibitors tested against certain filamentous fungi. Efficacy of KA synergism in decreasing order was pyraclostrobin > kresoxim-methyl > antimycin A. KA was also found to be a chemosensitizer of cells to hydrogen peroxide (H2O2, tested as a mimic of reactive oxygen species involved in host defense during infection, against several human fungal pathogens and Penicillium strains infecting crops. In comparison, KA-mediated chemosensitization to complex III inhibitors/H2O2 was undetectable in other types of fungi, including Aspergillus flavus, A. parasiticus, and P. griseofulvum, among others. Of note, KA was found to function as an antioxidant, but not as an antifungal chemosensitizer in yeasts. In summary, KA could serve as an antifungal chemosensitizer to complex III inhibitors or H2O2 against selected human pathogens or Penicillium species. KA-mediated chemosensitization to H2O2 seemed specific for filamentous fungi. Thus, results indicate strain- and/or drug-specificity exist during KA chemosensitization.

SIGNIFICANCE OF LACTATE DEHYDROGENASE AND ASPARTATE TRANSAMINASE AS BIOCHEMICAL MARKERS AND AS PREDICTORS OF SEVERITY OF PREGNANCY-INDUCED HYPERTENSION AND ITS COMPLICATIONS

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Ramesh Sonowal

2017-03-01

Full Text Available BACKGROUND To compare serum Lactate Dehydrogenase (LDH and serum Aspartate Transaminase (AST of normotensive pregnant women with those of preeclamptic and eclamptic women. To determine the relationship of levels of serum lactate dehydrogenase and serum aspartate transaminase with severity of pregnancy-induced hypertension and its complications. MATERIALSAND METHODS The study was carried out on pregnant hypertensive patients attending outpatient department of Obstetrics and Gynaecology department, AMCH, Dibrugarh, Assam from 1 st July 2013 to 30 th June 2014. Normotensive pregnant women were taken as controls. Each serum sample from both the control group as well as study group was estimated for lactate dehydrogenase and aspartate transaminase using standard methods and a comparison is drawn and analysed using t-test and Chi-square test. RESULTS Serum lactate dehydrogenase and serum aspartate transaminase levels were higher in the study group in comparison to the study groups. The mean serum LDH was 198±30.03U/L in control group, whereas in preeclampsia and eclampsia, mean serum levels of LDH were 817±114U/L and 927±108U/L, respectively. The levels of the serum AST were found to be less than 600U/L in normotensive and preeclampsia patients and more than 600 U/L in eclampsia and other complications of PIH. CONCLUSION Serum lactate dehydrogenase and serum aspartate transaminase levels in patients suffering from preeclampsia and its complications are consistently higher compared to the normotensive pregnant patients. To determine the usefulness of inclusion of these enzymes along with other cardiac enzymes in the panel of investigations of pregnant women universally needs further large scale comparative studies.

Role of Acid and weakly acidic reflux in gastroesophageal reflux disease off proton pump inhibitor therapy.

Science.gov (United States)

Sung, Hea Jung; Cho, Yu Kyung; Moon, Sung Jin; Kim, Jin Su; Lim, Chul Hyun; Park, Jae Myung; Lee, In Seok; Kim, Sang Woo; Choi, Myung-Gye

2012-07-01

Available data about reflux patterns and symptom determinants in the gastroesophageal reflux disease (GERD) subtypes off proton pump inhibitor (PPI) therapy are lacking. We aimed to evaluate reflux patterns and determinants of symptom perception in patients with GERD off PPI therapy by impedance-pH monitoring. We retrospectively reviewed the impedance-pH data in patients diagnosed as GERD based on results of impedance-pH monitoring, endoscopy and/or typical symptoms. The characteristics of acid and weakly acidic reflux were evaluated. Symptomatic and asymptomatic reflux were compared according to GERD subtypes and individual symptoms. Forty-two patients (22 males, mean age 46 years) were diagnosed as GERD (17 erosive reflux disease, 9 pH(+) non-erosive reflux disease [NERD], 9 hypersensitive esophagus and 7 symptomatic NERD). A total of 1,725 reflux episodes were detected (855 acid [50%], 857 weakly acidic [50%] and 13 weakly alkaline reflux [Acid reflux was more frequently symptomatic and bolus clearance was longer compared with weakly acidic reflux. In terms of globus, weakly acidic reflux was more symptomatic. Symptomatic reflux was more frequently acid and mixed reflux; these associations were more pronounced in erosive reflux disease and symptomatic NERD. The perception of regurgitation was related to acid reflux, while that of globus was more related to weakly acidic reflux. In patients not taking PPI, acid reflux was more frequently symptomatic and had longer bolus clearance. Symptomatic reflux was more frequently acid and mixed type; however, weakly acidic reflux was associated more with globus. These data suggest a role for impedance-pH data in the evaluation of globus.

The effect of a histone deacetylase inhibitor - valproic acid - on nucleoli in human leukaemic myeloblasts.

Science.gov (United States)

Smetana, K; Zápotocký, M

2010-01-01

The present study was undertaken to provide more information on nucleolar changes induced by a histone deacetylase inhibitor such as valproic acid in leukaemic myeloblasts at the single-cell level. For this study, RNA in nucleoli was visualized by a simple but sensitive cytochemical procedure in unfixed cytospins of short-term bone marrow cultures from patients suffering from acute myeloid leukaemia. Valproic acid in leukaemic myeloblasts markedly reduced the nucleolar size and also produced significant transformation of "active" to "resting" and "inactive" nucleoli that reflected the alteration of the nucleolar transcription in sensitive myeloblasts. On this occasion it should be added that valproic acid significantly increased the incidence of altered myeloblasts that changed to apoptotic cells or apoptotic bodies and cell ghosts. In contrast to the above-mentioned decreased nucleolar size, the nucleolar RNA concentration, expressed by computerassisted RNA image densitometry in valproic acidtreated myeloblasts, was not significantly changed. The results of the present study clearly indicated that the nucleolar size and transformation of "active" to "sleeping" or "inactive" nucleoli are convenient markers of the sensitivity and alteration of leukaemic myeloblasts produced by a histone deacetylase inhibitor, valproic acid, at the single-cell level.

Metabolomic analysis reveals key metabolites related to the rapid adaptation of Saccharomyce cerevisiae to multiple inhibitors of furfural, acetic acid, and phenol.

Science.gov (United States)

Wang, Xin; Li, Bing-Zhi; Ding, Ming-Zhu; Zhang, Wei-Wen; Yuan, Ying-Jin

2013-03-01

During hydrolysis of lignocellulosic biomass, a broad range of inhibitors are generated, which interfere with yeast growth and bioethanol production. In order to improve the strain tolerance to multiple inhibitors--acetic acid, furfural, and phenol (three representative lignocellulose-derived inhibitors) and uncover the underlying tolerant mechanism, an adaptation experiment was performed in which the industrial Saccharomyces cerevisiae was cultivated repeatedly in a medium containing multiple inhibitors. The adaptation occurred quickly, accompanied with distinct increase in growth rate, glucose utilization rate, furfural metabolism rate, and ethanol yield, only after the first transfer. A similar rapid adaptation was also observed for the lab strains of BY4742 and BY4743. The metabolomic analysis was employed to investigate the responses of the industrial S. cereviaise to three inhibitors during the adaptation. The results showed that higher levels of 2-furoic acid, 2, 3-butanediol, intermediates in glycolytic pathway, and amino acids derived from glycolysis, were discovered in the adapted strains, suggesting that enhanced metabolic activity in these pathways may relate to resistance against inhibitors. Additionally, through single-gene knockouts, several genes related to alanine metabolism, GABA shunt, and glycerol metabolism were verified to be crucial for the resistance to multiple inhibitors. This study provides new insights into the tolerance mechanism against multiple inhibitors, and guides for the improvement of tolerant ethanologenic yeast strains for lignocellulose-bioethanol fermentation.

A Practical and Fast Method To Predict the Thermodynamic Preference of omega-Transaminase-Based Transformations

DEFF Research Database (Denmark)

Meier, Robert J.; Gundersen Deslauriers, Maria; Woodley, John

2015-01-01

A simple, easy-to-use, and fast approach method is proposed and validated that can predict whether a transaminase reaction is thermodynamically unfavourable. This allowed us to de-select, in the present case, at least 50% of the reactions because they were thermodynamically unfavourable as confir...

Polyaspartic acid as a corrosion inhibitor for WE43 magnesium alloy

Directory of Open Access Journals (Sweden)

Lihui Yang

2015-03-01

Full Text Available The inhibition behavior of polyaspartic acid (PASP as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.% NaCl solution by means for EIS measurement, potentiodynamic polarization curve, and scanning electron microscopy. The results show that PASP can inhibit the corrosion of WE43 magnesium alloy. The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study.

Potent and Selective Peptidyl Boronic Acid Inhibitors of the Serine Protease Prostate-Specific Antigen

Science.gov (United States)

LeBeau, Aaron M.; Singh, Pratap; Isaacs, John T.; Denmeade, Samuel R.

2012-01-01

SUMMARY Prostate cancer cells produce high (microgram to milligram/milliliter) levels of the serine protease Prostate-Specific Antigen (PSA). PSA is enzymatically active in the extracellular fluid surrounding prostate cancers but is found at 1,000- to 10,000-fold lower concentrations in the circulation, where it is inactivated due to binding to abundant serum protease inhibitors. The exclusive presence of high levels of active PSA within prostate cancer sites makes PSA an attractive candidate for targeted imaging and therapeutics. A synthetic approach based on a peptide substrate identified first peptide aldehyde and then boronic acid inhibitors of PSA. The best of these had the sequence Cbz-Ser-Ser-Lys-Leu-(boro)Leu, with a Ki for PSA of 65 nM. The inhibitor had a 60-fold higher Ki for chymotrypsin. A validated model of PSA’s catalytic site confirmed the critical interactions between the inhibitor and residues within the PSA enzyme. PMID:18635003

Role of Acid and Weakly Acidic Reflux in Gastroesophageal Reflux Disease Off Proton Pump Inhibitor Therapy

Science.gov (United States)

Sung, Hea Jung; Moon, Sung Jin; Kim, Jin Su; Lim, Chul Hyun; Park, Jae Myung; Lee, In Seok; Kim, Sang Woo; Choi, Myung-Gye

2012-01-01

Background/Aims Available data about reflux patterns and symptom determinants in the gastroesophageal reflux disease (GERD) subtypes off proton pump inhibitor (PPI) therapy are lacking. We aimed to evaluate reflux patterns and determinants of symptom perception in patients with GERD off PPI therapy by impedance-pH monitoring. Methods We retrospectively reviewed the impedance-pH data in patients diagnosed as GERD based on results of impedance-pH monitoring, endoscopy and/or typical symptoms. The characteristics of acid and weakly acidic reflux were evaluated. Symptomatic and asymptomatic reflux were compared according to GERD subtypes and individual symptoms. Results Forty-two patients (22 males, mean age 46 years) were diagnosed as GERD (17 erosive reflux disease, 9 pH(+) non-erosive reflux disease [NERD], 9 hypersensitive esophagus and 7 symptomatic NERD). A total of 1,725 reflux episodes were detected (855 acid [50%], 857 weakly acidic [50%] and 13 weakly alkaline reflux [reflux was more frequently symptomatic and bolus clearance was longer compared with weakly acidic reflux. In terms of globus, weakly acidic reflux was more symptomatic. Symptomatic reflux was more frequently acid and mixed reflux; these associations were more pronounced in erosive reflux disease and symptomatic NERD. The perception of regurgitation was related to acid reflux, while that of globus was more related to weakly acidic reflux. Conclusions In patients not taking PPI, acid reflux was more frequently symptomatic and had longer bolus clearance. Symptomatic reflux was more frequently acid and mixed type; however, weakly acidic reflux was associated more with globus. These data suggest a role for impedance-pH data in the evaluation of globus. PMID:22837877

Benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives as inhibitors of the corrosion of aluminium in hydrochloric acid.

Science.gov (United States)

Fouda, A S; Gouda, M M; El-Rahman, S I

2000-05-01

The effect of benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives on the corrosion of aluminium in hydrochloric acid has been investigated using thermometric and polarization techniques. The inhibitive efficiency ranking of these compounds from both techniques was found to be: 2>3>1>4. The inhibitors acted as mixed-type inhibitors but the cathode is more polarized. The relative inhibitive efficiency of these compounds has been explained on the basis of structure of the inhibitors and their mode of interaction at the surface. Results show that these additives are adsorbed on an aluminium surface according to the Langmuir isotherm. Polarization measurements indicated that the rate of corrosion of aluminium rapidly increases with temperature over the range 30-55 degrees C both in the absence and in the presence of inhibitors. Some thermodynamic data of the adsorption process are calculated and discussed.

Insulin-induced inhibition of gluconeogenesis genes, including glutamic pyruvic transaminase 2, is associated with reduced histone acetylation in a human liver cell line.

Science.gov (United States)

Honma, Kazue; Kamikubo, Michiko; Mochizuki, Kazuki; Goda, Toshinao

2017-06-01

Hepatic glutamic pyruvic transaminase (GPT; also known as alanine aminotransferase) is a gluconeogenesis enzyme that catalyzes conversions between alanine and pyruvic acid. It is also used as a blood biomarker for hepatic damage. In this study, we investigated whether insulin regulates GPT expression, as it does for other gluconeogenesis genes, and if this involves the epigenetic modification of histone acetylation. Human liver-derived HepG2 cells were cultured with 0.5-100nM insulin for 8h, and the mRNA expression of GPT, glutamic-oxaloacetic transaminase (GOT), γ-glutamyltransferase (GGT), PCK1, G6PC and FBP1 was measured. We also investigated the extent of histone acetylation around these genes. Insulin suppressed the mRNA expression of gluconeogenesis genes (GPT2, GOT1, GOT2, GGT1, GGT2, G6PC, and PCK1) in HepG2 cells in a dose-dependent manner. mRNA levels of GPT2, but not GPT1, were decreased by insulin. Histone acetylation was also reduced around GPT2, G6PC, and PCK1 in response to insulin. The expression of GPT2 and other gluconeogenesis genes such as G6PC and PCK1 was suppressed by insulin, in association with decreases in histone H3 and H4 acetylation surrounding these genes. Copyright © 2017 Elsevier Inc. All rights reserved.

Selections of minimal conditions for a simple intensification and scale up of w-transaminase reactions

DEFF Research Database (Denmark)

Gundersen, Maria T.; Lloyd, Richard C; Woodley, John

A step wise decision matrix is presented to quickly evaluate w - transaminase for a ‘simple scale up’ in the synthetic direction . Here a ‘simple scale up’ is defined as a system without specialized equipment or process development, thus a rapid implementation . The three step method consists...

Effects of dietary chromium exposure to rockfish, Sebastes schlegelii are ameliorated by ascorbic acid.

Science.gov (United States)

Kim, Jun-Hwan; Kang, Ju-Chan

2017-05-01

Juvenile rockfish Sebastes schlegelii (mean length 10.8±1.4cm, and mean weight 31.7±3.6g) were exposed for 4 weeks with the different levels of dietary chromium (Cr 6+ ) at 0, 120 and 240mg/L and ascorbic acids (AsA) at 100, 200 and 400mg/L. Significant accumulation occurred in specific tissues and hematological parameters were altered: red blood cell count, hematocrit, and hemoglobin increased; plasma components were altered including calcium, glucose, cholesterol, total protein, glutamic oxalate transaminase, and glutamic pyruvate transaminase. However, magnesium and alkaline phosphatase concentrations were unchanged. Ascorbic acids reduced both chromium uptake into tissues and altered hematological parameters. Copyright © 2017. Published by Elsevier Inc.

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

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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.

Hydroxamic acid derivatives as potent peptide deformylase inhibitors and antibacterial agents.

Science.gov (United States)

Apfel, C; Banner, D W; Bur, D; Dietz, M; Hirata, T; Hubschwerlen, C; Locher, H; Page, M G; Pirson, W; Rossé, G; Specklin, J L

2000-06-15

Low-molecular-weight beta-sulfonyl- and beta-sulfinylhydroxamic acid derivatives have been synthesized and found to be potent inhibitors of Escherichia coli peptide deformylase (PDF). Most of the compounds synthesized and tested displayed antibacterial activities that cover several pathogens found in respiratory tract infections, including Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The potential of these compounds as antibacterial agents is discussed with respect to selectivity, intracellular concentrations in bacteria, and potential for resistance development.

Bioassay-directed fractionation of a blood coagulation factor Xa inhibitor, betulinic acid from Lycopus lucidus

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Tan Yin-Feng

2018-03-01

Full Text Available Thrombosis is a major cause of morbidity and mortality worldwide and plays a pivotal role in the pathogenesis of several cardiovascular disorders, including acute coronary syndrome, unstable angina, myocardial infarction, sudden cardiac death, peripheral arterial occlusion, ischemic stroke, deep-vein thrombosis, and pulmonary embolism. Anticoagulants, antiplatelet agents, and fibrinolytics can reduce the risks of these clinical events. Especially, the blood coagulation factor Xa (FXa inhibitor is a proven anticoagulant. Promoting blood circulation, using traditional Chinese medicine (TCM, for the treatment of these diseases has been safely used for thousands of years in clinical practice. Therefore, highly safe and effective anticoagulant ingredients, including FXa inhibitors, could be found in TCM for activating the blood circulation. One FXa inhibitor, a pentacyclic triterpene (compound 1, betulinic acid characterized by IR, MS and NMR analyses, was isolated from the ethyl acetate fraction of Lycopus lucidus by bioassay-directed fractionation. Compound 1 exhibited an inhibitory effect on FXa with IC50 25.05 μmol/L and reduced the thrombus weight in an animal model at 25-100 mg/kg. These results indicate that betulinic acid could be the potential for anticoagulant therapy.

Dipicolinic Acid Derivatives as Inhibitors of New Delhi Metallo-β-lactamase-1.

Science.gov (United States)

Chen, Allie Y; Thomas, Pei W; Stewart, Alesha C; Bergstrom, Alexander; Cheng, Zishuo; Miller, Callie; Bethel, Christopher R; Marshall, Steven H; Credille, Cy V; Riley, Christopher L; Page, Richard C; Bonomo, Robert A; Crowder, Michael W; Tierney, David L; Fast, Walter; Cohen, Seth M

2017-09-14

The efficacy of β-lactam antibiotics is threatened by the emergence and global spread of metallo-β-lactamase (MBL) mediated resistance, specifically New Delhi metallo-β-lactamase-1 (NDM-1). By utilization of fragment-based drug discovery (FBDD), a new class of inhibitors for NDM-1 and two related β-lactamases, IMP-1 and VIM-2, was identified. On the basis of 2,6-dipicolinic acid (DPA), several libraries were synthesized for structure-activity relationship (SAR) analysis. Inhibitor 36 (IC 50 = 80 nM) was identified to be highly selective for MBLs when compared to other Zn(II) metalloenzymes. While DPA displayed a propensity to chelate metal ions from NDM-1, 36 formed a stable NDM-1:Zn(II):inhibitor ternary complex, as demonstrated by 1 H NMR, electron paramagnetic resonance (EPR) spectroscopy, equilibrium dialysis, intrinsic tryptophan fluorescence emission, and UV-vis spectroscopy. When coadministered with 36 (at concentrations nontoxic to mammalian cells), the minimum inhibitory concentrations (MICs) of imipenem against clinical isolates of Eschericia coli and Klebsiella pneumoniae harboring NDM-1 were reduced to susceptible levels.

Cefuroxime axetil: A commercially available drug as corrosion inhibitor for aluminum in hydrochloric acid solution

OpenAIRE

Ameh, Paul O.; Sani, Umar M.

2016-01-01

Cefuroxime axetil (CA) a prodrug was tested as corrosion inhibitor for aluminum in hydrochloric acid solution using thermometric, gasometric weight loss and scanning electron microscope (SEM) techniques. Results obtained showed that this compound has a good inhibiting properties for aluminum corrosion in acidic medium, with inhibition efficiencies values reaching 89.87 % at 0.5 g / L . It was also found out that the results from weight loss method are highly consistent with those obtained by ...

Some aromatic hydrazone derivatives as inhibitors for the corrosion of C-steel in phosphoric acid solution.

Science.gov (United States)

Fouda, Abd El-Aziz S; Al-Sarawy, Ahmed A; Radwan, Mohamed S

2006-01-01

The effect of furfural benzoylhydrazone and its derivatives (I-VII) as corrosion inhibitors for C-steel in 1M phosphoric acid solution has been studied by weight-loss and galvanostatic polarization techniques. A significant decrease in the corrosion rate of C-steel was observed in the presence of the investigated inhibitors. This study revealed that, the inhibition efficiency increases with increasing the inhibitor concentration, and the addition of iodide ions enhances it to a considerable extent. The effect of temperature on the inhibition efficiency of these compounds was studied using weight-loss method. Activation energy (E(a)*) and other thermodynamic parameters for the corrosion process were calculated and discussed. The galvanostatic polarization data indicated that, the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The adsorption of these compounds on C-steel surface has been found to obey Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

Inhibitor chymotrypsynowy nasion wiechliny łąkowej (Poa pratensis [Chymotrypsin inhibitor from Poa pratensis seeds

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I. Lorenc-Kubis

2015-01-01

Full Text Available A chymotrypsin inhibitor was isolated from Poa pratensis seeds. The inhibitor showed also antytriptic activity. It is a termostable protein, soluble in water, sodium chloride, but insoluble in 5% trichloracetic acid and 0.15 M sulphosalicylic acid.

Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

Energy Technology Data Exchange (ETDEWEB)

Rotaru, Ileana [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Varvara, Simona, E-mail: svarvara@uab.ro [Department of Exact Sciences and Engineering, “1 Decembrie 1918” University, 11-13 Nicolae Iorga St., 510009 Alba Iulia (Romania); Gaina, Luiza [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Muresan, Liana Maria, E-mail: limur@chem.ubbcluj.ro [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania)

2014-12-01

Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E{sub HOMO} and E{sub LUMO} and HOMO–LUMO energy gap were used for correlation with the corrosion data.

Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

International Nuclear Information System (INIS)

Rotaru, Ileana; Varvara, Simona; Gaina, Luiza; Muresan, Liana Maria

2014-01-01

Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E HOMO and E LUMO and HOMO–LUMO energy gap were used for correlation with the corrosion data

pKa modulation of the acid/base catalyst within GH32 and GH68: a role in substrate/inhibitor specificity?

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Shuguang Yuan

Full Text Available Glycoside hydrolases of families 32 (GH32 and 68 (GH68 belong to clan GH-J, containing hydrolytic enzymes (sucrose/fructans as donor substrates and fructosyltransferases (sucrose/fructans as donor and acceptor substrates. In GH32 members, some of the sugar substrates can also function as inhibitors, this regulatory aspect further adding to the complexity in enzyme functionalities within this family. Although 3D structural information becomes increasingly available within this clan and huge progress has been made on structure-function relationships, it is not clear why some sugars bind as inhibitors without being catalyzed. Conserved aspartate and glutamate residues are well known to act as nucleophile and acid/bases within this clan. Based on the available 3D structures of enzymes and enzyme-ligand complexes as well as docking simulations, we calculated the pKa of the acid-base before and after substrate binding. The obtained results strongly suggest that most GH-J members show an acid-base catalyst that is not sufficiently protonated before ligand entrance, while the acid-base can be fully protonated when a substrate, but not an inhibitor, enters the catalytic pocket. This provides a new mechanistic insight aiming at understanding the complex substrate and inhibitor specificities observed within the GH-J clan. Moreover, besides the effect of substrate entrance on its own, we strongly suggest that a highly conserved arginine residue (in the RDP motif rather than the previously proposed Tyr motif (not conserved provides the proton to increase the pKa of the acid-base catalyst.

Functional loss of GABA transaminase (GABA-T expressed early leaf senescence under various stress conditions in Arabidopsis thaliana

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Syed Uzma Jalil

2017-06-01

Full Text Available GABA-transaminase (GABA-T involved in carbon and nitrogen metabolism during the plant development process via GABA shunt and GABA-T mutant, which is defective in GABA catabolism, is ideal model to examine the role of GABA-T in plant development and leaf senescence of plant. We have characterized GABA transaminase knock out mutant pop2-1 that is transition and pop2-3 which is T-DNA insertion mutant of Arabidopsis thaliana during various stress conditions.The GABA-T knockout mutant plants displayed precocious leaf senescence, which was accompanied by the assays of physiological parameters of leaf senescence during various stress conditions. Furthermore, our physiological evidence indicates that pop2-1 and pop2-3 mutations rapidly decreased the efficiency of leaf photosynthesis, chlorophyll content, GABA content, GABA-T, and glutamate decarboxylase (GAD activity and on the other hand increases membrane ion leakage, malondialdehyde (MDA level in stress induced leaves. However, cell viability assay by trypan blue and insitu Hydrogen peroxidation assay by 3,3-diaminobenzidine (DAB in stress induced leaves also display that pop2-1 and pop2-3 mutant leaves show oversensitivity in response to different stress conditions as compared to wild type. These results strongly indicate that the loss-of-function of GABA transaminase gene induces early leaf senescence in Arabidopsis thaliana during various stress conditions.

A new structural class of subtype-selective inhibitor of cloned excitatory amino acid transporter, EAAT2

DEFF Research Database (Denmark)

Bräuner-Osborne, Hans; Hermit, M B; Nielsen, B

2000-01-01

We have studied the pharmacological effects of (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) and the enantiomers of (RS)-2-amino-3-(3-hydroxy-1,2, 5-thiadiazol-4-yl)propionic acid (TDPA) on cloned human excitatory amino acid transporter subtypes 1, 2 and 3 (EAAT1......-3) expressed in Cos-7 cells. Whereas AMPA and (R)-TDPA were both inactive as inhibitors of [3H]-(R)-aspartic acid uptake on all three EAAT subtypes, (S)-TDPA was shown to selectively inhibit uptake by EAAT2 with a potency equal to that of the endogenous ligand (S)-glutamic acid. (S)-TDPA thus represents a new...

Secretion of alpha 2-plasmin inhibitor is impaired by amino acid deletion in a small region of the molecule.

Science.gov (United States)

Toyota, S; Hirosawa, S; Aoki, N

1994-02-01

Alpha 2-plasmin inhibitor (alpha 2PI) deficiency Okinawa results from defective secretion of the inhibitor from the liver and appears to be a direct consequence of the deletion of Glu137 in the amino acid sequence of alpha 2PI. To examine the effects of replacing the amino acid occupying position 137 or deleting its neighboring amino acid on alpha 2PI secretion, we used oligonucleotide-directed mutagenesis of alpha 2PI cDNA to change the codon specifying Glu137 or delete a codon specifying its neighboring amino acid. The effects were determined by pulse-chase experiments and by enzyme-linked immunosorbent assay of media from transiently transfected COS-7 cells. Replacement of Glu137 with an amino acid other than Cys had little effect on alpha 2PI secretion. In contrast, deletion of an amino acid in a region spanning a sequence of less than 30 amino acids including positions 127 and 137 severely impaired the secretion. The results suggest that structural integrity of the region, rather than its component amino acids, is important for the intracellular transport and secretion of alpha 2PI.

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.

THE EFFECT OF METHANOGENIC INHIBITOR FEED ON PROPIONIC ACID AND LAMB MEAT CHEMICAL QUALITY

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E. Suryanto

2012-09-01

Full Text Available This study aimed to determine the effect of medium chain fatty acids (MCFA on propionic acids and lamb meat chemical quality. The treatment given was R1: feed without medium chain fatty acids (MCFA, while R2 dan R3 were the feed contained 1.0% and 1.5% of MCFA, respectively. The twelve heads of lambs yearling weight of 16-17 kg were used as materials. Biological trial was done for three months and then was slaughtered. Before being slaughtered, the animal was taken rumen fluid to be analyzed for propionic acid. The carcass was sampled to be analyzed for chemical composition, cholesterol and fatty acids content. This study showed that methanogenic inhibitor feed with 1.0-1.5% MCFA could be used as sheep feed, and the results: the propionic acid content in rumen increased 29.59 – 36.11%. The cholesterol content decreased 7.14-10.06%. For the meat fatty acids composition, unsaturated fatty acids increased 9.05 – 17.96%. while saturated fatty acid decreased 6.59 – 11.88%.

Increased availability of NADH in metabolically engineered baker's yeast improves transaminase-oxidoreductase coupled asymmetric whole-cell bioconversion

DEFF Research Database (Denmark)

Knudsen, Jenny Dahl; Hägglöf, Cecilia; Weber, Nora

2016-01-01

yeast for transamination-reduction coupled asymmetric one-pot conversion was investigated. RESULTS: A series of active whole-cell biocatalysts were constructed by over-expressing the (S)-selective ω-transaminase (VAMT) from Capsicum chinense together with the NADH-dependent (S)-selective alcohol...

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.

Hydrogen exchange during cell-free incorporation of deuterated amino acids and an approach to its inhibition

Energy Technology Data Exchange (ETDEWEB)

Tonelli, Marco; Singarapu, Kiran K. [University of Wisconsin-Madison, National Magnetic Resonance Facility at Madison (NMRFAM), Department of Biochemistry (United States); Makino, Shin-ichi; Sahu, Sarata C.; Matsubara, Yuko [University of Wisconsin-Madison, Center for Eukaryotic Structural Genomics (CESG), Department of Biochemistry (United States); Endo, Yaeta [Ehime University, Cell-Free Science and Technology Research Center (Japan); Kainosho, Masatsune [Tokyo Metropolitan University, Center for Priority Areas (Japan); Markley, John L., E-mail: markley@nmrfam.wisc.edu [University of Wisconsin-Madison, National Magnetic Resonance Facility at Madison (NMRFAM), Department of Biochemistry (United States)

2011-12-15

Perdeuteration, selective deuteration, and stereo array isotope labeling (SAIL) are valuable strategies for NMR studies of larger proteins and membrane proteins. To minimize scrambling of the label, it is best to use cell-free methods to prepare selectively labeled proteins. However, when proteins are prepared from deuterated amino acids by cell-free translation in H{sub 2}O, exchange reactions can lead to contamination of {sup 2}H sites by {sup 1}H from the solvent. Examination of a sample of SAIL-chlorella ubiquitin prepared by Escherichia coli cell-free synthesis revealed that exchange had occurred at several residues (mainly at Gly, Ala, Asp, Asn, Glu, and Gln). We present results from a study aimed at identifying the exchanging sites and level of exchange and at testing a strategy for minimizing {sup 1}H contamination during wheat germ cell-free translation of proteins produced from deuterated amino acids by adding known inhibitors of transaminases (1 mM aminooxyacetic acid) and glutamate synthetase (0.1 mM l-methionine sulfoximine). By using a wheat germ cell-free expression system, we produced [U-{sup 2}H, {sup 15}N]-chlorella ubiquitin without and with added inhibitors, and [U-{sup 15}N]-chlorella ubiquitin as a reference to determine the extent of deuterium incorporation. We also prepared a sample of [U-{sup 13}C, {sup 15}N]-chlorella ubiquitin, for use in assigning the sites of exchange. The added inhibitors did not reduce the protein yield and were successful in blocking hydrogen exchange at C{sup {alpha}} sites, with the exception of Gly, and at C{sup {beta}} sites of Ala. We discovered, in addition, that partial exchange occurred with or without the inhibitors at certain side-chain methyl and methylene groups: Asn-H{sup {beta}}, Asp-H{sup {beta}}, Gln-H{sup {gamma}}, Glu-H{sup {gamma}}, and Lys-H{sup {epsilon}}. The side-chain labeling pattern, in particular the mixed chiral labeling resulting from partial exchange at certain sites, should be of

Outcomes in patients with nonerosive reflux disease treated with a proton pump inhibitor and alginic acid ± glycyrrhetinic acid and anthocyanosides

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Di Pierro F

2013-03-01

Full Text Available Francesco Di Pierro,1 Mario Gatti,2 Giuliana Rapacioli,3 Leandro Ivaldi4 1Velleja Research, Milan, 2Gastroenterology Department, Giussano Hospital, Monza-Brianza, 3AIOR, Piacenza, 4Digestive Endoscopic Department, Ceva Hospital, Ceva, Cuneo, Italy Background: The purpose of this study was to compare the efficacy of alginic acid alone versus alginic acid combined with low doses of pure glycyrrhetinic acid and bilberry anthocyanosides as an addon to conventional proton pump inhibitor therapy in relieving symptoms associated with nonerosive reflux disease. Methods: This prospective, randomized, 8-week, open-label trial was conducted at two centers. Sixty-three patients with persistent symptoms of gastroesophageal reflux disease and normal upper gastrointestinal endoscopy were eligible for the study. Patients in group A (n = 31 were treated with pantoprazole and a formula (Mirgeal® containing alginic acid and low doses of pure glycyrrhetinic acid + standardized Vaccinium myrtillus extract for 4 weeks, then crossed over to the multi-ingredient formula for a further 4 weeks. Patients in group B (n = 32 were treated pantoprazole and alginic acid alone twice daily, then crossed over to alginic acid twice daily for a further 4 weeks. Efficacy was assessed by medical evaluation of a symptom relief score, estimated using a visual analog scale (0–10. Side effects, tolerability, and compliance were also assessed. Results: Of the 63 patients enrolled in the study, 58 (29 in group A and 29 in group B completed the 8-week trial. The baseline characteristics were comparable between the two groups. During the study, significant differences were recorded in symptom scores for both groups. In group A, symptoms of chest pain, heartburn, and abdominal swelling were less serious than in group B. Treatment A was better tolerated, did not induce hypertension, and had fewer side effects than treatment B. No significant differences in compliance were found between the

Identification of Na+/K+-ATPase inhibitors in bovine plasma as fatty acids and hydrocarbons

DEFF Research Database (Denmark)

Tal, D M; Yanuck, M D; Van Hall, Gerrit

1989-01-01

A preparative purification of endogenous inhibitors of the Na+/K+-ATPase has been carried out from bovine blood. Dried plasma was deproteinized, hexane-extracted and desalted, followed by further purification through a series of reverse-phase HPLC fractionations. Fractions active in inhibiting Na...... ouabain, and in addition it enhanced ouabain binding at high dilutions. These properties are indicative of nonspecific interactions with the Na+/K+-ATPase. The active fraction was identified by TLC, HPLC, NMR, GLC and GC-MS, to be a mixture of three unesterified fatty acids, mainly oleic acid (72...

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

Identification of novel functional inhibitors of acid sphingomyelinase.

Directory of Open Access Journals (Sweden)

Johannes Kornhuber

Full Text Available We describe a hitherto unknown feature for 27 small drug-like molecules, namely functional inhibition of acid sphingomyelinase (ASM. These entities named FIASMAs (Functional Inhibitors of Acid SphingoMyelinAse, therefore, can be potentially used to treat diseases associated with enhanced activity of ASM, such as Alzheimer's disease, major depression, radiation- and chemotherapy-induced apoptosis and endotoxic shock syndrome. Residual activity of ASM measured in the presence of 10 µM drug concentration shows a bimodal distribution; thus the tested drugs can be classified into two groups with lower and higher inhibitory activity. All FIASMAs share distinct physicochemical properties in showing lipophilic and weakly basic properties. Hierarchical clustering of Tanimoto coefficients revealed that FIASMAs occur among drugs of various chemical scaffolds. Moreover, FIASMAs more frequently violate Lipinski's Rule-of-Five than compounds without effect on ASM. Inhibition of ASM appears to be associated with good permeability across the blood-brain barrier. In the present investigation, we developed a novel structure-property-activity relationship by using a random forest-based binary classification learner. Virtual screening revealed that only six out of 768 (0.78% compounds of natural products functionally inhibit ASM, whereas this inhibitory activity occurs in 135 out of 2028 (6.66% drugs licensed for medical use in humans.

The gamma-aminobutyric acid uptake inhibitor, tiagabine, is anticonvulsant in two animal models of reflex epilepsy.

Science.gov (United States)

Smith, S E; Parvez, N S; Chapman, A G; Meldrum, B S

1995-02-06

The effects of i.p. administration of the gamma-aminobutyric acid (GABA) uptake inhibitors R(-)N-(4,4-di(3-methylthien-2-yl)-but-3-enyl) nipecotic acid hydrochloride (tiagabine; molecular weight 412.0), (1-(2-(((diphenylmethylene)-amino)oxy)ethyl)-1,2,5,6-tetrahydro-3- pyridinecarboxylic acid hydrochloride (NNC-711; molecular weight 386.9), and (+/-)-nipecotic acid (molecular weight 128.2) are compared with those of carbamazepine (molecular weight 236.3) on sound-induced seizures and locomotor performance in genetically epilepsy-prone (GEP) rats. The ED50 value against clonic seizures (in mumol kg-1 at the time of maximal anticonvulsant effect) for tiagabine was 23 (0.5 h), and for NNC-711 was 72 (1 h), and for carbamazepine was 98 (2 h). (+/-)-Nipecotic acid (0.4-15.6 mmol kg-1) was not anticonvulsant. High doses of NNC-711 (207-310 mumol kg-1) and of (+/-)-nipecotic acid (39-78 mmol kg-1) induced ataxia and myoclonic seizures 0.25-1 h. Tiagabine and carbamazepine did not induce myoclonic seizures and had similar therapeutic indices (locomotor deficit ED50/anticonvulsant ED50) ranging from 0.4 to 1.9. In Papio papio, we observed a reduction in photically induced myoclonic seizures with tiagabine (2.4 mumol kg-1 i.v.) accompanied with neurological impairment. Tiagabine has comparable anticonvulsant action to carbamazepine in rats and has anticonvulsant effects in non-human primates supporting the potential use of inhibitors of GABA uptake as therapy for epilepsy.

Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

Energy Technology Data Exchange (ETDEWEB)

Deng Shuduan, E-mail: dengshuduan@163.co [Faculty of Wood Science and Decoration Technology, Southwest Forestry University, Kunming 650224 (China); Li Xianghong; Fu Hui [Department of Fundamental Courses, Southwest Forestry University, Kunming 650224 (China)

2011-02-15

Research highlights: Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

International Nuclear Information System (INIS)

Deng Shuduan; Li Xianghong; Fu Hui

2011-01-01

Research highlights: → Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. → The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. → For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. → Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

Hydroxybenzoic Acid Derivatives as Dual-Target Ligands: Mitochondriotropic Antioxidants and Cholinesterase Inhibitors.

Science.gov (United States)

Oliveira, Catarina; Cagide, Fernando; Teixeira, José; Amorim, Ricardo; Sequeira, Lisa; Mesiti, Francesco; Silva, Tiago; Garrido, Jorge; Remião, Fernando; Vilar, Santiago; Uriarte, Eugenio; Oliveira, Paulo J; Borges, Fernanda

2018-01-01

Alzheimer's disease (AD) is a multifactorial age-related disease associated with oxidative stress (OS) and impaired cholinergic transmission. Accordingly, targeting mitochondrial OS and restoring cholinergic transmission can be an effective therapeutic strategy toward AD. Herein, we report for the first time dual-target hydroxybenzoic acid (HBAc) derivatives acting as mitochondriotropic antioxidants and cholinesterase (ChE) inhibitors. The studies were performed with two mitochondriotropic antioxidants AntiOxBEN 1 (catechol derivative), and AntiOxBEN 2 (pyrogallol derivative) and compounds 15-18 , which have longer spacers. Compounds AntiOxBEN 1 and 15 , with a shorter carbon chain spacer (six- and eight-carbon) were shown to be potent antioxidants and BChE inhibitors (IC 50 = 85 ± 5 and 106 ± 5 nM, respectively), while compounds 17 and 18 with a 10-carbon chain were more effective AChE inhibitors (IC 50 = 7.7 ± 0.4 and 7.2 ± 0.5 μM, respectively). Interestingly, molecular modeling data pointed toward bifunctional ChEs inhibitors. The most promising ChE inhibitors acted by a non-competitive mechanism. In general, with exception of compounds 15 and 17 , no cytotoxic effects were observed in differentiated human neuroblastoma (SH-SY5Y) and human hepatocarcinoma (HepG2) cells, while Aβ-induced cytotoxicity was significantly prevented by the new dual-target HBAc derivatives. Overall, due to its BChE selectivity, favorable toxicological profile, neuroprotective activity and drug-like properties, which suggested blood-brain barrier (BBB) permeability, the mitochondriotropic antioxidant AntiOxBEN 1 is considered a valid lead candidate for the development of dual acting drugs for AD and other mitochondrial OS-related diseases.

Hydroxybenzoic Acid Derivatives as Dual-Target Ligands: Mitochondriotropic Antioxidants and Cholinesterase Inhibitors

Directory of Open Access Journals (Sweden)

Catarina Oliveira

2018-04-01

Full Text Available Alzheimer's disease (AD is a multifactorial age-related disease associated with oxidative stress (OS and impaired cholinergic transmission. Accordingly, targeting mitochondrial OS and restoring cholinergic transmission can be an effective therapeutic strategy toward AD. Herein, we report for the first time dual-target hydroxybenzoic acid (HBAc derivatives acting as mitochondriotropic antioxidants and cholinesterase (ChE inhibitors. The studies were performed with two mitochondriotropic antioxidants AntiOxBEN1 (catechol derivative, and AntiOxBEN2 (pyrogallol derivative and compounds 15–18, which have longer spacers. Compounds AntiOxBEN1 and 15, with a shorter carbon chain spacer (six- and eight-carbon were shown to be potent antioxidants and BChE inhibitors (IC50 = 85 ± 5 and 106 ± 5 nM, respectively, while compounds 17 and 18 with a 10-carbon chain were more effective AChE inhibitors (IC50 = 7.7 ± 0.4 and 7.2 ± 0.5 μM, respectively. Interestingly, molecular modeling data pointed toward bifunctional ChEs inhibitors. The most promising ChE inhibitors acted by a non-competitive mechanism. In general, with exception of compounds 15 and 17, no cytotoxic effects were observed in differentiated human neuroblastoma (SH-SY5Y and human hepatocarcinoma (HepG2 cells, while Aβ-induced cytotoxicity was significantly prevented by the new dual-target HBAc derivatives. Overall, due to its BChE selectivity, favorable toxicological profile, neuroprotective activity and drug-like properties, which suggested blood-brain barrier (BBB permeability, the mitochondriotropic antioxidant AntiOxBEN1 is considered a valid lead candidate for the development of dual acting drugs for AD and other mitochondrial OS-related diseases.

Hydroxybenzoic acid derivatives as dual-target ligands: mitochondriotropic antioxidants and cholinesterase inhibitors

Science.gov (United States)

Oliveira, Catarina; Cagide, Fernando; Teixeira, José; Amorim, Ricardo; Sequeira, Lisa; Mesiti, Francesco; Silva, Tiago; Garrido, Jorge; Remião, Fernando; Vilar, Santiago; Uriarte, Eugenio; Oliveira, Paulo J.; Borges, Fernanda

2018-04-01

Alzheimer’s disease (AD) is a multifactorial age-related disease associated with oxidative stress (OS) and impaired cholinergic transmission. Accordingly, targeting mitochondrial OS and restoring cholinergic transmission can be an effective therapeutic strategy towards AD. Herein, we report for the first time dual-target hydroxybenzoic acid (HBAc) derivatives acting as mitochondriotropic antioxidants and cholinesterase (ChE) inhibitors. The studies were performed with two mitochondriotropic antioxidants AntiOxBEN1 (catechol derivative), and AntiOxBEN2 (pyrogallol derivative) and compounds 15-18, which have longer spacers. Compounds AntiOxBEN1 and 15, with a shorter carbon chain spacer (six- and eight-carbon) were shown to be potent antioxidants and BChE inhibitors (IC50 = 85 ± 5 and 106 ± 5 nM, respectively), while compounds 17 and 18 with a ten-carbon chain were more effective AChE inhibitors (IC50 = 7.7 ± 0.4 and 7.2 ± 0.5 nM, respectively). Interestingly, molecular modelling data pointed towards bifunctional ChEs inhibitors. The most promising ChE inhibitors acted by a non-competitive mechanism. In general, with exception of compounds 15 and 17, no cytotoxic effects were observed in differentiated human neuroblastoma (SH-SY5Y) and human hepatocarcinoma (HepG2) cells, while Αβ-induced cytotoxicity was significantly prevented by the new dual-target HBAc derivatives. Overall, due to its BChE selectivity, favourable toxicological profile, neuroprotective activity and drug-like properties, which suggested blood-brain barrier (BBB) permeability, the mitochondriotropic antioxidant AntiOxBEN1 is considered a valid lead candidate for the development of dual acting drugs for AD and other mitochondrial OS-related disease

Identification, expression and characterization of an R-ω-transaminase from Capronia semiimmersa.

Science.gov (United States)

Iglesias, César; Panizza, Paola; Rodriguez Giordano, Sonia

2017-07-01

Chiral amines are essential precursors in the production of biologically active compounds, including several important drugs. Among the biocatalytic strategies that have been developed for their synthesis, the use of ω-transaminases (ω-TA) appears as an attractive alternative allowing the stereoselective amination of prochiral ketones. However, the problems associated with narrow substrate specificity, unfavourable reaction equilibrium and expensive amine donors still hamper its industrial application. The search for novel enzymes from nature can contribute to expand the catalytic repertoire of ω-TA and help to circumvent some of these problems. A genome mining approach, based on the work described by Höhne et al., was applied for selection of potential R-ω-TA. Additional criteria were used to select an enzyme that differs from previously described ones. A candidate R-ω-TA from Capronia semiimmersa was selected, cloned and expressed in Escherichia coli. Interestingly, alignment of this enzyme with previously reported TA sequences revealed the presence of two additional amino acid residues in a loop close to the active site. The impact of this change was analysed with a structural model based on crystallized R-ω-TAs. Analysis of the substrate specificity of R-ω-TA from C. semiimmersa indicates that it accepts a diversity of ketones as substrates yielding the corresponding amine with good yields and excellent enantioselectivity. The expressed enzyme accepts isopropylamine as amine donor what makes it suitable for industrial processes.

Proton pump inhibitor-responsive chronic cough without acid reflux: a case report

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Nobata Kouichi

2007-08-01

Full Text Available Abstract Background Because 24-h esophageal pH monitoring is quite invasive, the diagnosis of gastroesophageal reflux disease (GERD-associated cough has usually been made based merely on the clinical efficacy of treatment with proton pump inhibitor (PPI. Case presentation We recently encountered two patients with PPI-responsive chronic non-productive cough for whom switching from bronchodilators and glucocorticosteroids to PPI resulted in improvement of cough. The cough returned nearly to pre-administration level a few weeks after discontinuation of PPI. Though GERD-associated cough was suspected, 24-h esophageal pH monitoring revealed that the cough rarely involved gastric acid reflux. Following re-initiation of PPI, the cough disappeared again. Conclusion PPI may improve cough unrelated to gastric acid reflux.

Aminocarnitine and acylaminocarnitines: Carnitine acyltransferase inhibitors affecting long-chain fatty acid and glucose metabolism

International Nuclear Information System (INIS)

Clark, D.J.

1989-01-01

DL-Aminocarnitine (DL-3-amino-4-trimethylaminobutyrate) and the acylaminocarnitines acetyl-, decanoyl- and palmitoyl-DL-aminocarnitine have been synthesized and tested as inhibitors of carnitine palmitoyl-transferase and carnitine acetyltransferase in vitro and in vivo. Acetyl-DL-aaminocarnitine is the most potent reversible inhibitor of carnitine acetyltransferase reported to date, and is competitive with respect to acetyl-L-carnitine. Mice given acetyl-DL-aminocarnitine metabolize [U- 14 C]acetyl-L-carnitine at about 60% of the rate of control mice. Palmitoyl-DL-aminocarnitine is the most potent reversible inhibitor of carnitine palmitoyltransferase reported to date. Decanoyl-DL-aminocarnitine and DL-aminocarnitine are also very potent inhibitors; all compounds inhibit the catabolism of [ 14 C]palmitate to 14 CO 2 in intact mice by at least 50%. Carnitine palmitoyltransferase controls the entry of long-chain fatty acids into the mitochondrial matrix for β-oxidation. The inhibition of carnitine palmitoyltransferase by aminocarnitine or acylaminocarnitines in vivo prevents or reverses ketogenesis in fasted mice, and causes the reversible accumulation of triglycerides in liver, kidney and plasma. Administration of DL-aminocarnitine to streptozotocindiabetic mice lowers plasma glucose levels and improves the glucose tolerance test

The coupling of ω-transaminase and Oppenauer oxidation reactions via intra-membrane multicomponent diffusion – A process model for the synthesis of chiral amines

DEFF Research Database (Denmark)

Esparza-Isunza, T.; González-Brambila, M.; Gani, Rafiqul

2015-01-01

amine product. Using 2-propylamine as the amine donor of the ω-transaminase reaction, gives acetone as a by-product, which in turn allows the coupling of the ω-transaminase reaction with the Oppenauer oxidation. The Oppenauer reaction converts secondary alcohols into ketones, and these can subsequently......In this study we consider the theoretical coupling of an otherwise thermodynamically limited ω-transaminase reaction to an Oppenauer oxidation, in order to shift the equilibria of both reactions, with the aim of achieving a significant (and important) increase in the yield of the desired chiral...... of this paper is to report the development of a mathematical model as a tool for the simulation and potential design of such a process for the production of a range of chiral amines. The mathematical model developed considers that each reaction is performed in a single ideally mixed isothermal reactor operating...

Effects of norflurazon, an inhibitor of carotenogenesis, on abscisic acid and xanthoxin in the caps of gravistimulated maize roots

Science.gov (United States)

Feldman, L. J.; Sun, P. S.

1986-01-01

Maize seeds were germinated in the dark in the presence of the carotenoid synthesis inhibitor norflurazon and the levels of abscisic acid, xanthoxin and total carotenoids were measured in the root cap and in the adjacent 1.5 mm segment. In norflurazon-treated roots abscisic acid levels were markedly reduced, but an increase occurred in the levels of xanthoxin, a compound structurally and physiologically similar to abscisic acid. In the cultivar of maize (Zea mays L. cv. Merit) used for this work, brief illumination of the root is required for gravitropic curving. Following illumination both control and norflurazon-treated roots showed normal gravitropic curvature; however, the rate of curvature was delayed in norflurazon-treated roots. Our data from norflurazon-treated roots are consistent with a role for xanthoxin in maize root gravitropism. The increase in xanthoxin in the presence of an inhibitor of carotenoid synthesis suggests that xanthoxin and abscisic acid originate, at least in part, via different metabolic pathways.

Effect of deoxyribonucleic acid replication inhibitors on bacterial recombination

International Nuclear Information System (INIS)

Canosi, U.; Siccardi, A.G.; Falaschi, A.; Mazza, G.

1976-01-01

Two inhibitors of replicative deoxyribonucleic acid (DNA) synthesis, nalidixic acid (NAL) and 6-(p-hydroxyphenylazo)-uracil (HPUra), showed different effects on genetic recombination and DNA repair in Bacillus subtilis. Previous work (Pedrini et al., 1972) showed that NAL does not interfere with the transformation process of B. subtilis. The results reported in this work demonstrated that the drug was also without effect on the transfection SPP1 or SPO-1 phage DNA (a process that requires a recombination event). The drug was also ineffective on the host cell reactivation of ultraviolet-irradiated SPP1 phage, as well as on transfection with ultraviolet-irradiated DNA of the same phage. HPUra instead markedly reduced the transformation process, as well as transfection, by SPO-1 DNA, but it did not affect the host cell reactivation of SPO-1 phage. In conclusion, whereas the NAL target seems to be specific for replicative DNA synthesis, the HPUra target (i.e., the DNA polymerase III of B. subtilis) seems to be involved also in recombination, but not in the excision repair process. The mutations conferring NAL and HPUra resistance used in this work were mapped by PBS-1 transduction

Pronounced radiosensitization of cultured human cancer cells by COX inhibitor under acidic microenvironment

International Nuclear Information System (INIS)

Shah, Tushar; Ryu, Samuel; Lee, Ho Jun; Brown, Stephen; Kim, Jae Ho

2002-01-01

Purpose: To demonstrate the influence of pH on the cytotoxicity and radiosensitization by COX (cyclooxygenase) -1 and -2 inhibitors using established human cancer cells in culture. Methods and Materials: Nonselective COX inhibitor, ibuprofen (IB), and selective COX-2 inhibitor, SC-236, were used to determine the cytotoxicity and radiosensitization at varying pH of culture media. Human colon carcinoma cell line (HT-29) was exposed to the drug alone and in combination with radiation at different pH of the cell culture media. The end point was clonogenic ability of the single-plated cells after the treatment. Results: Cytotoxicity and radiosensitization of IB increased with higher drug concentration and longer exposure time. The most significant radiosensitization was seen with IB (1.5 mM) for 2-h treatment at pH 6.7 before irradiation. The dose-modifying factor as defined by the ratio of radiation doses required to achieve the same effect on cell survival was 1.8 at 10% survival level. In contrast, SC-236 (50 μM for 2-8 h) showed no pH-dependent cytotoxicity. There was modest increase in the cell killing at lower doses of radiation. Conclusion: An acidic pH was an important factor affecting the increased cytotoxicity and radiosensitization by ibuprofen. Radiation response was enhanced at shoulder portion of the cell survival curve by selective COX-2 inhibitor

Evaluation of potential interactions between mycophenolic acid derivatives and proton pump inhibitors.

Science.gov (United States)

Gabardi, Steven; Olyaei, Ali

2012-01-01

To evaluate the incidence of gastrointestinal (GI) complications in solid organ transplant (SOT) recipients, impact of the complications on transplant outcomes, and the potential interactions between mycophenolic acid (MPA) derivatives and proton pump inhibitors (PPIs). An unrestricted literature search (1980-January 2012) was performed with MEDLINE and EMBASE using the following key words: drug-drug interaction, enteric-coated mycophenolic acid, GI complications, mycophenolate mofetil, solid organ transplant, and proton pump inhibitor, including individual agents within the class. Abstracts from scientific meetings were also evaluated. Additionally, reference citations from identified publications were reviewed. Relevant English-language, original research articles and review articles were evaluated if they focused on any of the topics identified in the search or included substantial content addressing GI complications in SOT recipients or drug interactions. GI complications are frequent among SOT recipients, with some studies showing prevalence rates as high as 70%. Transplant outcomes among renal transplant recipients are significantly impacted by GI complications, especially in patients requiring immunosuppressant dosage reductions or premature discontinuation. To this end, PPI use among patients receiving transplants is common. Recent data demonstrate that PPIs significantly reduce the overall exposure to MPA after oral administration of mycophenolate mofetil. Similar studies show this interaction does not exist between PPIs and enteric-coated mycophenolic acid (EC-MPA). Unfortunately, most of the available data evaluating this interaction are pharmacokinetic analyses that do not investigate the clinical impact of this interaction. A significant interaction exists between PPIs and mycophenolate mofetil secondary to reduced dissolution of mycophenolate mofetil in higher pH environments. EC-MPA is not absorbed in the stomach; therefore, low intragastric acidity

Varic acid analogues from fungus as PTP1B inhibitors: Biological evaluation and structure-activity relationships.

Science.gov (United States)

Sun, Wenlong; Zhuang, Chunlin; Li, Xia; Zhang, Bowei; Lu, Xinhua; Zheng, Zhihui; Dong, Yuesheng

2017-08-01

Protein tyrosine phosphatase 1B (PTP1B) inhibitors as potential therapies for diabetes and obesity have attracted much attention in recent years. Six varic acid analogues were isolated from two strains of fungi and evaluated for PTP1B inhibition activities. The structure-activity relationships were also characterized and predicted by molecular modeling. Further kinetic studies indicated the reversible and competitive inhibition manner of varic acid analogues. Trivaric acid showed insulin-sensitizing effect not only in vitro but also in vivo, representing a promising lead compound for further optimization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neutrophil elastase inhibitor, ONO-5046, modulates acid-induced lung and systemic injury in rabbits.

Science.gov (United States)

Kaneko, K; Kudoh, I; Hattori, S; Yamada, H; Ohara, M; Wiener-Kronish, J; Okumura, F

1997-09-01

Acid instillation leads to direct lung and to secondary systemic organ injury, probably via activated macrophages and neutrophils. This study investigated the effects of neutrophil elastase on organ injury after unilateral lung acid instillation by administrating a specific neutrophil elastase inhibitor, ONO-5046, before acid instillation. Three groups of anesthetized rabbits (n = 12 in each group) underwent tracheostomies, and instillations were made into their right lower lobe airspaces with either phosphate buffered saline (pH, 7.4; volume, 1.2 ml/kg; n = 12) or HCl (pH, 1.25; volume, 1.2 ml/kg; n = 24). In half of the acid-instilled rabbits, ONO-5046, 10 mg/kg, was given intravenously 15 min before the HCl instillation, and then 10 mg x kg(-1) x h(-1) of the drug was continuously infused throughout the experiment. The other groups of animals received the vehicle intravenously. Anesthesia and mechanical ventilation was continued for 8 h, whereas arterial blood gases were sampled intermittently. Eight hours after saline or acid instillation, the animals were killed, and their lungs, heart, kidneys, liver, and small intestines were harvested. Wet-to-dry weight ratios (W/ D) and myeloperoxidase (MPO) assays of these organs were done, and elastase assays on the bronchoalveolar lavage fluids (BALF) obtained from each lung also were performed. Pretreatment with ONO-5046 attenuated the physiologic changes seen in the vehicle-treated animals. Significant decreases in W/D of the noninstilled lungs and of the small intestine and normalization of the oxygenation of the experimental animals occurred. The ONO-5046 pretreatment did not affect the neutrophil sequestration in the lungs or in the other organs as determined by neutrophil counts in BALF and by the MPO assays. A neutrophil elastase inhibitor, ONO-5046, administered immediately before acid instillation attenuated the physiologic changes seen in the vehicle-treated animals. The drug blocked neutrophil elastase but

Isolation of 4,5-O-Dicaffeoylquinic Acid as a Pigmentation Inhibitor Occurring in Artemisia capillaris Thunberg and Its Validation In Vivo

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Nadia Tabassum

2016-01-01

Full Text Available There is a continual need to develop novel and effective melanogenesis inhibitors for the prevention of hyperpigmentation disorders. The plant Artemisia capillaris Thunberg (Oriental Wormwood was screened for antipigmentation activity using murine cultured cells (B16-F10 malignant melanocytes. Activity-based fractionation using HPLC and NMR analyses identified the compound 4,5-O-dicaffeoylquinic acid as an active component in this plant. 4,5-O-Dicaffeoylquinic acid significantly reduced melanin synthesis and tyrosinase activity in a dose-dependent manner in the melanocytes. In addition, 4,5-O-dicaffeoylquinic acid treatment reduced the expression of tyrosinase-related protein-1. Significantly, we could validate the antipigmentation activity of this compound in vivo, using a zebrafish model. Moreover, 4,5-O-dicaffeoylquinic acid did not show toxicity in this animal model. Our discovery of 4,5-O-dicaffeoylquinic acid as an inhibitor of pigmentation that is active in vivo shows that this compound can be developed as an active component for formulations to treat pigmentation disorders.

Isolation of 4,5-O-Dicaffeoylquinic Acid as a Pigmentation Inhibitor Occurring in Artemisia capillaris Thunberg and Its Validation In Vivo.

Science.gov (United States)

Tabassum, Nadia; Lee, Ji-Hyung; Yim, Soon-Ho; Batkhuu, Galzad Javzan; Jung, Da-Woon; Williams, Darren R

2016-01-01

There is a continual need to develop novel and effective melanogenesis inhibitors for the prevention of hyperpigmentation disorders. The plant Artemisia capillaris Thunberg (Oriental Wormwood) was screened for antipigmentation activity using murine cultured cells (B16-F10 malignant melanocytes). Activity-based fractionation using HPLC and NMR analyses identified the compound 4,5-O-dicaffeoylquinic acid as an active component in this plant. 4,5-O-Dicaffeoylquinic acid significantly reduced melanin synthesis and tyrosinase activity in a dose-dependent manner in the melanocytes. In addition, 4,5-O-dicaffeoylquinic acid treatment reduced the expression of tyrosinase-related protein-1. Significantly, we could validate the antipigmentation activity of this compound in vivo, using a zebrafish model. Moreover, 4,5-O-dicaffeoylquinic acid did not show toxicity in this animal model. Our discovery of 4,5-O-dicaffeoylquinic acid as an inhibitor of pigmentation that is active in vivo shows that this compound can be developed as an active component for formulations to treat pigmentation disorders.

NÍVEIS SÉRICOS DE TRANSAMINASE GLUTÂMICA-OXALACÉTICA (GOT E TRANSAMINASE GLUTÂMICA-PIRÚVICA (GPT EM BOVINOS DO ESTADO DE GOIÁS SERUM LEVELS OF GOT AND GPT IN BOVINES IN THE GOIÁS STATE

Directory of Open Access Journals (Sweden)

Eduardo Cavalheiro Jardim

2007-09-01

Full Text Available

Foram analisados 162 hemossoros de bovinos mestiços zebu com a finalidade de obtenção dos níveis séricos da transaminase glutâmica-oxalacética e da transaminase glutâmica-pirúvica, de 18 bezerros(as, 31 novilhos(as e 83 vacas, procedentes de municípios do Estado de Goiás. Os valores encontrados foram os seguintes (URF: TGO, 77,5 +/- 27,3 (bezerros(as, 72,9 +/- 19,6 (novilhos(as e 81,8 +/- 28,4 (vacas; TGP, 29,5 +/- 8,1 (novilhos(as, 31,1 +/- 8.3 (novilhos(as e 34,1 +/- 10,6 (vacas. É muito difícil estandadizar condições de manejo, e os dados encontrados no presente trabalho confirmam que as transaminases são enzimas, dinâmicas, capazes de responderem rapidamente a um grande número de trocas fisiológicas. Posteriores trabalhos devem ser desenvolvidos buscando uniformizar os grupos de trabalho sob os diferentes pontos considerados no presente estudo.

With the objective of studying the serum levels of GPT and GOT, 162 blood serum from crossbred zebu were analyzed. The blood was taken from 48 calves, 31 steers and 83 cows from farms of counties in the State of Goiás. GOT serum levels (URF were as fo1lows: calves, 72.5 +/- 27.3, steers, 72.9 +/- 19.6 and cows 81.8 +/-28.4. For GPT serum levels (URF was found: calves, 29.5 +/- 8.1, steers, 31.1 +/- 8.3 and cows 34.1 +/- 10.6. Some differences were found in GOT and GPT, in comparison with other foreign reports in mature cows.

Histone deacetylase inhibitor valproic acid promotes the induction of pluripotency in mouse fibroblasts by suppressing reprogramming-induced senescence stress

Energy Technology Data Exchange (ETDEWEB)

Zhai, Yingying; Chen, Xi; Yu, Dehai [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China); Stanford University Medical School, Palo Alto Veterans Institute for Research, Palo Alto, CA 94304 (United States); Li, Tao [Stanford University Medical School, Palo Alto Veterans Institute for Research, Palo Alto, CA 94304 (United States); Cui, Jiuwei; Wang, Guanjun [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China); Hu, Ji-Fan, E-mail: jifan@stanford.edu [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China); Stanford University Medical School, Palo Alto Veterans Institute for Research, Palo Alto, CA 94304 (United States); Li, Wei, E-mail: jdyylw@163.com [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China)

2015-09-10

Histone deacetylase inhibitor valproic acid (VPA) has been used to increase the reprogramming efficiency of induced pluripotent stem cell (iPSC) from somatic cells, yet the specific molecular mechanisms underlying this effect is unknown. Here, we demonstrate that reprogramming with lentiviruses carrying the iPSC-inducing factors (Oct4-Sox2-Klf4-cMyc, OSKM) caused senescence in mouse fibroblasts, establishing a stress barrier for cell reprogramming. Administration of VPA protected cells from reprogramming-induced senescent stress. Using an in vitro pre-mature senescence model, we found that VPA treatment increased cell proliferation and inhibited apoptosis through the suppression of the p16/p21 pathway. In addition, VPA also inhibited the G2/M phase blockage derived from the senescence stress. These findings highlight the role of VPA in breaking the cell senescence barrier required for the induction of pluripotency. - Highlights: • Histone deacetylase inhibitor valproic acid enhances iPSC induction. • Valproic acid suppresses reprogramming-induced senescence stress. • Valproic acid downregulates the p16/p21 pathway in reprogramming. • This study demonstrates a new mechanistic role of valproic acid in enhancing reprogramming.

Quantitative structure–activity relationship model for amino acids as corrosion inhibitors based on the support vector machine and molecular design

International Nuclear Information System (INIS)

Zhao, Hongxia; Zhang, Xiuhui; Ji, Lin; Hu, Haixiang; Li, Qianshu

2014-01-01

Highlights: • Nonlinear quantitative structure–activity relationship (QSAR) model was built by the support vector machine. • Descriptors for QSAR model were selected by principal component analysis. • Binding energy was taken as one of the descriptors for QSAR model. • Acidic solution and protonation of the inhibitor were considered. - Abstract: The inhibition performance of nineteen amino acids was studied by theoretical methods. The affection of acidic solution and protonation of inhibitor were considered in molecular dynamics simulation and the results indicated that the protonated amino-group was not adsorbed on Fe (1 1 0) surface. Additionally, a nonlinear quantitative structure–activity relationship (QSAR) model was built by the support vector machine. The correlation coefficient was 0.97 and the root mean square error, the differences between predicted and experimental inhibition efficiencies (%), was 1.48. Furthermore, five new amino acids were theoretically designed and their inhibition efficiencies were predicted by the built QSAR model

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.

Amino Acid Composition, Urease Activity and Trypsin Inhibitor Activity after Toasting of Soybean in Thick and Thin Layer

OpenAIRE

Krička, Tajana; Jurišić, Vanja; Voća, Neven; Ćurić, Duška; Brlek Savić, Tea; Matin, Ana

2009-01-01

The objective of this study was to determine amino acid content, urease activity and trypsin inhibitor activity in soybean grain for polygastric animals’ feed aft er toasting with the aim to introduce thick layer in toasting technology. Hence, soybean was toasted both in thick and thin layer at 130 oC during 10 minutes. In order to properly monitor the technological process of soybean thermal processing, it was necessary to study crude protein content, urease activity, trypsin inhibitor activ...

Differentiation of U937 cells induced by 5,8,11,14-eicosatetraynoic acid, a competitive inhibitor of arachidonic acid metabolism

International Nuclear Information System (INIS)

Ondrey, F.; Anderson, K.; Hoeltgen, D.; Harris, J.

1988-01-01

5,8,11,14-Eicosatetraynoic acid, a competitive inhibitor of arachidonic acid metabolism, rapidly and reversibly inhibited DNA synthesis in U937 cells. This inhibition was not due to cytotoxicity, as judged by studies with trypan blue, release of 51 Cr-labeled proteins, and its reversibility. When cells were cultured in the presence of ETYA for several days, morphologic, enzymatic, and functional changes consistent with differentiation occurred. The cells enlarged, the ratio of cytoplasm to nuclei increased, secretory granules and vacuoles developed, the apparent activity of nonspecific esterase rose, and ingestion of latex particles increased. A morphology consistent with that of an immature monocyte was evident by electron microscopy. When cells differentiated by ETYA were cultured in media free of the inhibitor, DNA synthesis reinitiated and the cell number increased; differentiation was phenotypic and not genotypic. To examine whether ETYA-induced differentiation was obligatorily related to its suppression of DNA synthesis, cells were incubated in 50 μM hydroxyurea and DNA synthesis was inhibited for 24 to 36 h without morphologic evidence of cellular differentiation. However, addition of ETYA to cells prevented from dividing by hydroxyurea and subsequent culture for 72 h induced morphologic evidence of differentiation. The effects of ETYA on cell division and cell differentiation are closely related but can be dissociated

New Coumarin Derivative as an Eco-Friendly Inhibitor of Corrosion of Mild Steel in Acid Medium

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Ahmed A. Al-Amiery

2014-12-01

Full Text Available The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxyacetohydrazide (EFCI, for mild steel (MS in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy, ELUMO (lowest unoccupied molecular orbital energy and μ (dipole moment, and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR and nuclear magnetic resonance (NMR spectroscopic studies.

Suppression of survivin expression in glioblastoma cells by the Ras inhibitor farnesylthiosalicylic acid promotes caspase-dependent apoptosis.

Science.gov (United States)

Blum, Roy; Jacob-Hirsch, Jasmine; Rechavi, Gideon; Kloog, Yoel

2006-09-01

The Ras inhibitor farnesylthiosalicylic acid (FTS) has been shown to induce apoptosis in glioblastoma multiforme, but its mechanism of action was unknown. We show that FTS or dominant-negative Ras, by deregulating extracellular signal-regulated kinase and Akt signaling, decreases survivin gene transcripts in U87 glioblastoma multiforme, leading to disappearance of survivin protein and cell death. FTS affected both Ras-controlled regulators of survivin transcription and Ras-regulated survival signals. Thus, Ras inhibition by FTS resulted in release of the survivin "brake" on apoptosis and in activation of the mitochondrial apoptotic pathway: dephosphorylation of Bad, activation of Bax, release of cytochrome c, and caspase activation. FTS-induced apoptosis of U87 cells was strongly attenuated by forced expression of survivin or by caspase inhibitors. These results show that resistance to apoptosis in glioblastoma multiforme can be abolished by a single Ras inhibitor, which targets both survivin, a critical inhibitor of apoptosis, and the intrinsic mitochondrial apoptotic machinery.

The effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status: a randomized trial among chronic hepatitis C virus-infected patients

DEFF Research Database (Denmark)

Groenbaek, K.; Friis, H.; Hansen, Max

2006-01-01

Objective To assess the effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status. Methods We performed a randomized, placebo-controlled, double-blind trial to assess the effect of antioxidant supplementation on serum alanine aminotransferase, plasma...... hepatitis C viral load as well as oxidative and antioxidant markers in patients with hepatitis C virus infection. The participants received a daily dose of ascorbic acid (500 mg), D-alpha-tocopherol (9451 U) and selenium (200 mu g) or placebo tablets for 6 months. Results Twenty-three patients were included...... aminotransferase and logo-transformed plasma hepatitis C virus-RNA between the groups or changes from the baseline at any time. No consistent differences between groups or changes from the baseline with respect to erythrocyte activities of antioxidative enzymes (glutathione reductase, superoxide dismutase...

Xanthium strumarium leaves extracts as a friendly corrosion inhibitor of low carbon steel in hydrochloric acid: Kinetics and mathematical studies

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Anees A. Khadom

2018-06-01

Full Text Available Corrosion inhibition of low carbon steel in 1 M HCl was investigated in absence and presence of Xanthium strumarium leaves (XSL extracts as a friendly corrosion inhibitor. The effect of temperature and inhibitor concentration was studied using weight loss method. The result obtained shown that Xanthium strumarium leaves extracts act as an inhibitor for low carbon steel in HCl and reduces the corrosion rate. The inhibition efficiency was found to increases with increase in inhibitor concentration and temperature. Higher inhibition efficiency was 94.82% at higher level of inhibitor concentration and temperature. The adsorption of Xanthium strumarium leaves extracts was found to obey Langmuir adsorption isotherm model. The values of the free energy of adsorption was more than −20 kJ/mol, which is indicative of mixed mode of physical and chemical adsorption. Keywords: Corrosion, Green inhibitor, Natural extracts, Low carbon steel, Acid, Adsorption

[The catalase inhibitor aminotriazole alleviates acute alcoholic liver injury].

Science.gov (United States)

Ai, Qing; Ge, Pu; Dai, Jie; Liang, Tian-Cai; Yang, Qing; Lin, Ling; Zhang, Li

2015-02-25

In this study, the effects of catalase (CAT) inhibitor aminotriazole (ATZ) on alcohol-induced acute liver injury were investigated to explore the potential roles of CAT in alcoholic liver injury. Acute liver injury was induced by intraperitoneal injection of alcohol in Sprague Dawley (SD) rats, and various doses of ATZ (100-400 mg/kg) or vehicle were administered intraperitoneally at 30 min before alcohol exposure. After 24 h of alcohol exposure, the levels of aspartate transaminase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) in plasma were determined. The degree of hepatic histopathological abnormality was observed by HE staining. The activity of hepatic CAT, hydrogen peroxide (H₂O₂) level and malondialdehyde (MDA) content in liver tissue were measured by corresponding kits. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in plasma were determined by ELISA method. The results showed that treatment with ATZ dose-dependently suppressed the elevation of ALT, AST and LDH levels induced by alcohol exposure, and that ATZ alleviated alcohol-induced histopathological alterations. Furthermore, ATZ inhibited the activity of CAT, reduced hepatic levels of H₂O₂and MDA in alcohol exposed rats. ATZ also decreased the levels of plasma TNF-α and IL-6 in rats with alcohol exposure. These results indicated that ATZ attenuated alcohol-induced acute liver injury in rats, suggesting that CAT might play important pathological roles in the pathogenesis of alcoholic liver injury.

Myrsinoic A acid and its derivative: in vitro inhibitors of photosynthesis

International Nuclear Information System (INIS)

Burger, Marcela Carmen de M.; Oliveira, Gracielle S. de; Menezes, Antonio Carlos S.; Vieira, Paulo Cezar; Silva, Maria Fatima das G.F. da; Veiga, Thiago A.M.

2012-01-01

Myrsinoic A acid, isolated from Myrsine cuneifolia and its hydrogenated derivative had their effect on photosynthesis tested. The compounds inhibited the electron flow (basal, phosphorylating and uncoupled) from water to methyl viologen; therefore, they act as Hill reaction inhibitors in spinach thylakoids. They inhibited partial reactions of PSII electron flow from water to 2,5-dichloro-1,4-benzoquinone, from water to sodium silicomolybdate, and partially electron flow from diphenylcarbazide to 2,6-dichloroindophenol. Their inhibition sites were at the donor and acceptor sides of PSII, between P 680 and Q A . Chlorophyll α fluorescence measurements confirmed the behavior of the compounds (pool of quinones). (author)

Identification of a D-amino acid decapeptide HIV-1 entry inhibitor

International Nuclear Information System (INIS)

Boggiano, Cesar; Jiang Shibo; Lu Hong; Zhao Qian; Liu Shuwen; Binley, James; Blondelle, Sylvie E.

2006-01-01

Entry of human immunodeficiency virus type 1 (HIV-1) virion into host cells involves three major steps, each being a potential target for the development of entry inhibitors: gp120 binding to CD4, gp120-CD4 complex interacting with a coreceptor, and gp41 refolding to form a six-helix bundle. Using a D-amino acid decapeptide combinatorial library, we identified peptide DC13 as having potent HIV-1 fusion inhibitory activity, and effectively inhibiting infection by several laboratory-adapted and primary HIV-1 strains. While DC13 did not block binding of gp120 to CD4, nor disrupt the gp41 six-helix bundle formation, it effectively blocked the binding of an anti-CXCR4 monoclonal antibody and chemokine SDF-1α to CXCR4-expressing cells. However, because R5-using primary viruses were also neutralized, the antiviral activity of DC13 implies additional mode(s) of action. These results suggest that DC13 is a useful HIV-1 coreceptor antagonist for CXCR4 and, due to its biostability and simplicity, may be of value for developing a new class of HIV-1 entry inhibitors

Can serum free fatty acids assessment predict severe preeclampsia ...

African Journals Online (AJOL)

Evaluation of serum fasting FFAs, uric acid, liver transaminases (AST, ALT) during delivery were done. Results: The mean level of FFAs was significantly elevated in preeclampsia cases compared to women with normal blood pressure (2.12 ± 2.64, 0.43± 0.29 respectively, p= 0.003). Also, cases with high FFAs levels had ...

Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

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R. Khandelwal

2011-01-01

Full Text Available The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to inhibit the corrosion rate. The study seeks to investigate the possibility of using extracts of Cordia dichotoma as a green corrosion inhibitor for mild steel.

Imidazopyridine-Based Fatty Acid Synthase Inhibitors That Show Anti-HCV Activity and in Vivo Target Modulation.

Science.gov (United States)

Oslob, Johan D; Johnson, Russell J; Cai, Haiying; Feng, Shirley Q; Hu, Lily; Kosaka, Yuko; Lai, Julie; Sivaraja, Mohanram; Tep, Samnang; Yang, Hanbiao; Zaharia, Cristiana A; Evanchik, Marc J; McDowell, Robert S

2013-01-10

Potent imidazopyridine-based inhibitors of fatty acid synthase (FASN) are described. The compounds are shown to have antiviral (HCV replicon) activities that track with their biochemical activities. The most potent analogue (compound 19) also inhibits rat FASN and inhibits de novo palmitate synthesis in vitro (cell-based) as well as in vivo.

Inhibitors for the corrosion of reactive metals: titanium and zirconium and their alloys in acid media

International Nuclear Information System (INIS)

Petit, J.A.; Chatainier, G.; Dabosi, F.

1981-01-01

The search for effective corrosion inhibitors for titanium and zirconium in acid media is growing because of the considerable increase in the use of these materials in chemical process equipment. It still remains limited, as appears from this review, because of the exceptionally high corrosion resistance of the metals. Titanium has received the greater attention. Its corrosion rate can be lowered by introduction in the medium of multivalent ions, inorganic and organic oxidants. Care should be taken to hold the concentration at a level exceeding some critical value, otherwise the corrosion rate increases. Complexing organic agents do not show such hazardous behaviour. The very rapid corrosion of titanium and zirconium in fluoride media may be lessened by complexing the fluoride ions. Though rarely encountered, localized corrosion may be avoided by using inhibitors. In some cases good corrosion inhibitors for titanium are dissolution accelerators for zirconium. (author)

Immobilization of Escherichia coli containing ω‐transaminase activity in LentiKats®

DEFF Research Database (Denmark)

Cárdenas‐Fernández, Max; Lima Afonso Neto, Watson; López, Carmen

2012-01-01

Whole Escherichia coli cells overexpressing ω‐transaminase (ω‐TA) and immobilized cells entrapped in LentiKats® were used as biocatalysts in the asymmetric synthesis of the aromatic chiral amines 1‐phenylethylamine (PEA) and 3‐amino‐1‐phenylbutane (APB). Whole cells were permeabilized...... whole cell biocatalysis, the reaction with IPA was one order of magnitude faster than with Ala. No reaction was detected when permeabilized E. coli cells containing ω‐TA were employed using Ala as the amino donor. Additionally, the synthesis of APB from 4‐phenyl‐2‐butanone and IPA was studied. Whole...

Combination Therapy of PPAR Ligands and Inhibitors of Arachidonic Acid in Lung Cancer

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Jordi Tauler

2008-01-01

Full Text Available Lung cancer is the leading cause of cancer death in the United States and five-year survival remains low. Numerous studies have shown that chronic inflammation may lead to progression of carcinogenesis. As a result of inflammatory stimulation, arachidonic acid (AA metabolism produces proliferation mediators through complex and dynamic interactions of the products of the LOX/COX enzymes. One important mediator in the activation of the AA pathways is the nuclear protein PPAR. Targeting LOX/COX enzymes and inducing activation of PPAR have resulted in significant reduction of cell growth in lung cancer cell lines. However, specific COX-inhibitors have been correlated with an increased cardiovascular risk. Clinical applications are still being explored with a novel generation of dual LOX/COX inhibitors. PPAR activation through synthetic ligands (TZDs has revealed a great mechanistic complexity since effects are produced through PPAR-dependent and -independent mechanisms. Furthermore, PPAR could also be involved in regulation of COX-2. Overexpression of PPAR has reported to play a role in control of invasion and differentiation. Exploring the function of PPAR, in this new context, may provide a better mechanistic model of its role in cancer and give an opportunity to design a more efficient therapeutic approach in combination with LOX/COX inhibitors.

Mechanism for release of arachidonic acid during guinea pig platelet aggregation: a role for the diacylglycerol lipase inhibitor RHC 80267

International Nuclear Information System (INIS)

Amin, D.

1986-01-01

The mechanism of the release of arachidonic acid from phospholipids after the stimulation of guinea pig platelets with collagen, thrombin and platelet activating factor (PAF) was studied. RHC 80267, a diacylglycerol lipase inhibitor, and indomethacin, a cyclooxygenase inhibitor, were used. Various in vitro assays for enzymes involved in arachidonic acid release and metabolism were conducted. Platelet aggregation and simultaneous release of ADP from platelets were monitored using a Chrono-log Lumiaggregometer. Platelets were labeled with ( 14 C)arachidonic acid to facilitate sensitive determination of small changes in platelet phospholipids during platelet aggregation. In the present investigation it is shown that collagen, thrombin and PAF increased phospholipase C activity. It was also discovered that cyclooxygenase products were responsible for further stimulation (a positive feed-back) of phospholipase C activity, while diacylglycerol provided a negative feed-back control over receptor-stimulated phospholipase C activity and inhibited ADP release. The guinea pig platelet is an ideal model to study phospholipase C-diacylglycerol lipase pathway for the release of arachidonic acid from platelet phospholipids because it does not have any phospholipase A 2 activity. It was observed that cyclooxygenase products were responsible for collagen-induced guinea pig platelet aggregation. Indomethacin completely inhibited collagen-induced platelet aggregation, was less effective against thrombin, and had no effect on PAF-induced platelet aggregation. On the other hand, RHC 80267 was a powerful inhibitor of aggregation and ADP release induced by all three of these potent aggregating agents

Glycyrrhetinic acid and its derivatives as inhibitors of poly(ADP-ribosepolymerases 1 and 2, apurinic/apyrimidinic endonuclease 1 and DNA polymerase β

Directory of Open Access Journals (Sweden)

Salakhutdinov N. F.

2012-06-01

Full Text Available Aim. For strengthening the efficiency of monofunctional alkylating antineoplastic drugs it is important to lower the capacity of base excision repair (BER system which corrects the majority of DNA damages caused by these reagents. The objective was to create inhibitors of the key BER enzymes (PARP1, PARP2, DNA polymerase β, and APE1 by the directed modification of glycyrrhetinic acid (GA. Methods. Amides of GA were produced from the GA acetate by formation of the corresponding acyl chloride, amidation with the appropriate amine and subsequent deacylation. Small library of 2-cyano substituted derivatives of GA methyl esters was obtained by the structural modification of GA framework and carboxylic acid group. The inhibitory capacity of the compounds was estimated by comparison of the enzyme activities in specific tests in the presence of compounds versus their absence. Results. None of tested compounds inhibits PARP1 significantly. Unmodified GA and its morpholinic derivative were shown to be weak inhibitors of PARP2. The derivatives of GA containing keto-group in 11 triterpene framework were shown to be moderate inhibitors of pol β. Compound 3, containing 12-oxo-9(11-en moiety in the ring C, was shown to be a single inhibitor of APE1 among all compounds studied. Conclusions. The class of GA derivatives, selective pol β inhibitors, was found out. The selective inhibitor of APE1 and weak selective inhibitor of PARP2 were also revealed.

Synchronization by food access modifies the daily variations in expression and activity of liver GABA transaminase.

Science.gov (United States)

De Ita-Pérez, Dalia; Méndez, Isabel; Vázquez-Martínez, Olivia; Villalobos-Leal, Mónica; Díaz-Muñoz, Mauricio

2014-01-01

Daytime restricted feeding (DRF) is an experimental protocol that influences the circadian timing system and underlies the expression of a biological clock known as the food entrained oscillator (FEO). Liver is the organ that reacts most rapidly to food restriction by adjusting the functional relationship between the molecular circadian clock and the metabolic networks. γ-Aminobutyric acid (GABA) is a signaling molecule in the liver, and able to modulate the cell cycle and apoptosis. This study was aimed at characterizing the expression and activity of the mostly mitochondrial enzyme GABA transaminase (GABA-T) during DRF/FEO expression. We found that DRF promotes a sustained increase of GABA-T in the liver homogenate and mitochondrial fraction throughout the entire day-night cycle. The higher amount of GABA-T promoted by DRF was not associated to changes in GABA-T mRNA or GABA-T activity. The GABA-T activity in the mitochondrial fraction even tended to decrease during the light period. We concluded that DRF influences the daily variations of GABA-T mRNA levels, stability, and catalytic activity of GABA-T. These data suggest that the liver GABAergic system responds to a metabolic challenge such as DRF and the concomitant appearance of the FEO.

Synchronization by Food Access Modifies the Daily Variations in Expression and Activity of Liver GABA Transaminase

Directory of Open Access Journals (Sweden)

Dalia De Ita-Pérez

2014-01-01

Full Text Available Daytime restricted feeding (DRF is an experimental protocol that influences the circadian timing system and underlies the expression of a biological clock known as the food entrained oscillator (FEO. Liver is the organ that reacts most rapidly to food restriction by adjusting the functional relationship between the molecular circadian clock and the metabolic networks. γ-Aminobutyric acid (GABA is a signaling molecule in the liver, and able to modulate the cell cycle and apoptosis. This study was aimed at characterizing the expression and activity of the mostly mitochondrial enzyme GABA transaminase (GABA-T during DRF/FEO expression. We found that DRF promotes a sustained increase of GABA-T in the liver homogenate and mitochondrial fraction throughout the entire day-night cycle. The higher amount of GABA-T promoted by DRF was not associated to changes in GABA-T mRNA or GABA-T activity. The GABA-T activity in the mitochondrial fraction even tended to decrease during the light period. We concluded that DRF influences the daily variations of GABA-T mRNA levels, stability, and catalytic activity of GABA-T. These data suggest that the liver GABAergic system responds to a metabolic challenge such as DRF and the concomitant appearance of the FEO.

The crucial protective role of glutathione against tienilic acid hepatotoxicity in rats

International Nuclear Information System (INIS)

Nishiya, Takayoshi; Mori, Kazuhiko; Hattori, Chiharu; Kai, Kiyonori; Kataoka, Hiroko; Masubuchi, Noriko; Jindo, Toshimasa; Manabe, Sunao

2008-01-01

To investigate the hepatotoxic potential of tienilic acid in vivo, we administered a single oral dose of tienilic acid to Sprague-Dawley rats and performed general clinicopathological examinations and hepatic gene expression analysis using Affymetrix microarrays. No change in the serum transaminases was noted at up to 1000 mg/kg, although slight elevation of the serum bile acid and bilirubin, and very mild hepatotoxic changes in morphology were observed. In contrast to the marginal clinicopathological changes, marked upregulation of the genes involved in glutathione biosynthesis [glutathione synthetase and glutamate-cysteine ligase (Gcl)], oxidative stress response [heme oxygenase-1 and NAD(P)H dehydrogenase quinone 1] and phase II drug metabolism (glutathione S-transferase and UDP glycosyltransferase 1A6) were noted after 3 or 6 h post-dosing. The hepatic reduced glutathione level decreased at 3-6 h, and then increased at 24 or 48 h, indicating that the upregulation of NF-E2-related factor 2 (Nrf2)-regulated gene and the late increase in hepatic glutathione are protective responses against the oxidative and/or electrophilic stresses caused by tienilic acid. In a subsequent experiment, tienilic acid in combination with L-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of Gcl caused marked elevation of serum alanine aminotransferase (ALT) with extensive centrilobular hepatocyte necrosis, whereas BSO alone showed no hepatotoxicity. The elevation of ALT by this combination was observed at the same dose levels of tienilic acid as the upregulation of the Nrf2-regulated genes by tienilic acid alone. In conclusion, these results suggest that the impairment of glutathione biosynthesis may play a critical role in the development of tienilic acid hepatotoxicity through extensive oxidative and/or electrophilic stresses

Adaptive laboratory evolution of ethanologenic Zymomonas mobilis strain tolerant to furfural and acetic acid inhibitors.

Science.gov (United States)

Shui, Zong-Xia; Qin, Han; Wu, Bo; Ruan, Zhi-yong; Wang, Lu-shang; Tan, Fu-Rong; Wang, Jing-Li; Tang, Xiao-Yu; Dai, Li-Chun; Hu, Guo-Quan; He, Ming-Xiong

2015-07-01

Furfural and acetic acid from lignocellulosic hydrolysates are the prevalent inhibitors to Zymomonas mobilis during cellulosic ethanol production. Developing a strain tolerant to furfural or acetic acid inhibitors is difficul by using rational engineering strategies due to poor understanding of their underlying molecular mechanisms. In this study, strategy of adaptive laboratory evolution (ALE) was used for development of a furfural and acetic acid-tolerant strain. After three round evolution, four evolved mutants (ZMA7-2, ZMA7-3, ZMF3-2, and ZMF3-3) that showed higher growth capacity were successfully obtained via ALE method. Based on the results of profiling of cell growth, glucose utilization, ethanol yield, and activity of key enzymes, two desired strains, ZMA7-2 and ZMF3-3, were achieved, which showed higher tolerance under 7 g/l acetic acid and 3 g/l furfural stress condition. Especially, it is the first report of Z. mobilis strain that could tolerate higher furfural. The best strain, Z. mobilis ZMF3-3, has showed 94.84% theoretical ethanol yield under 3-g/l furfural stress condition, and the theoretical ethanol yield of ZM4 is only 9.89%. Our study also demonstrated that ALE method might also be used as a powerful metabolic engineering tool for metabolic engineering in Z. mobilis. Furthermore, the two best strains could be used as novel host for further metabolic engineering in cellulosic ethanol or future biorefinery. Importantly, the two strains may also be used as novel-tolerant model organisms for the genetic mechanism on the "omics" level, which will provide some useful information for inverse metabolic engineering.

Ursodeoxycholic acid choleresis: Relationship to biliary HCO-3 and effects of Na+-H+ exchange inhibitors

International Nuclear Information System (INIS)

Renner, E.L.; Lake, J.R.; Cragoe, E.J. Jr.; van Dyke, R.W.; Scharschmidt, B.F.

1988-01-01

The authors have recently shown that substitution of Li + for perfusate Na + eliminates the HCO 3 - -rich choleresis produced by ursodeoxycholic acid (UDCA) in isolated perfused rat liver and that the increase in bile flow produced by both UDCA and taurocholic acid is partially inhibited by 1 mM amiloride. Although these findings are consistent with a role for Na + -H + exchange in the choleresis produced by these bile acids, both Li + substitution and amiloride affect other cellular processes, including Na + -K + -ATPase activity. They have now further explored both the relationship between UDCA-stimulated bile flow and biliary HCO 3 - secretion and the possible role of Na + -H + exchange in this process by comparing the effects of amiloride with two of its more potent and presumably more specific analogues, 5-(N,N-dimethyl)amiloride hydrochloride (DMA) and 5-(N-ethyl-N-isopropyl)amiloride (EIA). None of the inhibitors significantly altered biliary UDCA output or the relationship between UDCA-induced bile flow and either biliary [HCO 3 - ] or biliary HCO 3- output. Effects of these inhibitors did not appear attributable either to nonspecific toxicity, as reflected by hepatic release of lactate dehydrogenase or K + , or to inhibition of hepatic Na + -K + -ATPase, measured as Na + -dependent uptake of 86 Rb. These findings indicate that UDCA-induced but not basal bile formation is closely coupled to biliary HCO 3 - concentration and output, and they provide additional evidence that UDCA choleresis requires an intact Na + -H + exchange mechanism

Design and Synthesis of Bis-amide and Hydrazide-containing Derivatives of Malonic Acid as Potential HIV-1 Integrase Inhibitors

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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.

Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

Energy Technology Data Exchange (ETDEWEB)

Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

2011-11-15

The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

Acid sensing ion channel (ASIC) inhibitors exhibit anxiolytic-like activity in preclinical pharmacological models.

Science.gov (United States)

Dwyer, Jason M; Rizzo, Stacey J Sukoff; Neal, Sarah J; Lin, Qian; Jow, Flora; Arias, Robert L; Rosenzweig-Lipson, Sharon; Dunlop, John; Beyer, Chad E

2009-03-01

Acid sensing ion channels (ASICs) are proton-gated ion channels located in the central and peripheral nervous systems. Of particular interest is ASIC1a, which is located in areas associated with fear and anxiety behaviors. Recent reports suggest a role for ASIC1a in preclinical models of fear conditioning and anxiety. The present experiments evaluated various ASIC inhibitors in preclinical models of autonomic and behavioral parameters of anxiety. In addition, neurochemical studies evaluated the effects of an ASIC inhibitor (A-317567) on neurotransmitter levels in the amygdala. In electrophysiological studies using hippocampal primary neuronal cultures, three ASIC inhibitors (PcTX-1, A-317567, and amiloride) produced concentration-dependent inhibition of acid-evoked currents. In the stress-induced hyperthermia model, acute administration of psalmotoxin 1 (PcTX-1; 10-56 ng, i.c.v.), A-317567 (0.1-1.0 mg/kg, i.p.), and amiloride (10-100 mg/kg, i.p.) prevented stress-induced elevations in core body temperature. In the four-plate test, acute treatment with PcTX-1 (10-56 ng, i.c.v.) and A-317567 (0.01-0.1 mg/kg, i.p.), but not amiloride (3-100 mg/kg, i.p.), produced dose-dependent and significant increases in the number of punished crossings relative to vehicle-treated animals. Additionally, PcTX-1 (56-178 ng, i.c.v.), A-317567 (0.1-10 mg/kg, i.p.), and amiloride (10-100 mg/kg, i.p.) lacked significant anxiolytic-like activity in the elevated zero maze. In neurochemical studies, an infusion of A-317567 (100 microM) into the amygdala significantly elevated the extracellular levels of GABA, but not glutamate, in this brain region. These findings demonstrate that ASIC inhibition produces anxiolytic-like effects in some behavioral models and indicate a potential role for GABAergic mechanisms to underlie these anxiolytic-like effects.

Structural analysis and mutant growth properties reveal distinctive enzymatic and cellular roles for the three major L-alanine transaminases of Escherichia coli.

Science.gov (United States)

Peña-Soler, Esther; Fernandez, Francisco J; López-Estepa, Miguel; Garces, Fernando; Richardson, Andrew J; Quintana, Juan F; Rudd, Kenneth E; Coll, Miquel; Vega, M Cristina

2014-01-01

In order to maintain proper cellular function, the metabolism of the bacterial microbiota presents several mechanisms oriented to keep a correctly balanced amino acid pool. Central components of these mechanisms are enzymes with alanine transaminase activity, pyridoxal 5'-phosphate-dependent enzymes that interconvert alanine and pyruvate, thereby allowing the precise control of alanine and glutamate concentrations, two of the most abundant amino acids in the cellular amino acid pool. Here we report the 2.11-Å crystal structure of full-length AlaA from the model organism Escherichia coli, a major bacterial alanine aminotransferase, and compare its overall structure and active site composition with detailed atomic models of two other bacterial enzymes capable of catalyzing this reaction in vivo, AlaC and valine-pyruvate aminotransferase (AvtA). Apart from a narrow entry channel to the active site, a feature of this new crystal structure is the role of an active site loop that closes in upon binding of substrate-mimicking molecules, and which has only been previously reported in a plant enzyme. Comparison of the available structures indicates that beyond superficial differences, alanine aminotransferases of diverse phylogenetic origins share a universal reaction mechanism that depends on an array of highly conserved amino acid residues and is similarly regulated by various unrelated motifs. Despite this unifying mechanism and regulation, growth competition experiments demonstrate that AlaA, AlaC and AvtA are not freely exchangeable in vivo, suggesting that their functional repertoire is not completely redundant thus providing an explanation for their independent evolutionary conservation.

Adsorptive removal of fermentation inhibitors from concentrated acid hydrolyzates of lignocellulosic biomass.

Science.gov (United States)

Sainio, Tuomo; Turku, Irina; Heinonen, Jari

2011-05-01

Adsorptive purification of concentrated acid hydrolyzate of lignocellulose was investigated. Cation exchange resin (CS16GC), neutral polymer adsorbent (XAD-16), and granulated activated carbon (GAC) were studied to remove furfural, HMF, and acetic acid from a synthetic hydrolyzate containing 20 wt.% H(2)SO(4). Adsorption isotherms were determined experimentally. Loading and regeneration were investigated in a laboratory scale column. GAC has the highest adsorption capacity, but regeneration with water was not feasible. XAD-16 and CS16GC had lower adsorption capacities but also shorter cycle times due to easier regeneration. Productivity increased when regenerating with 50 wt.% EtOH(aq) solution. To compare adsorbents, process performance was quantified by productivity and fraction of inhibitors removed. GAC yields highest performance when high purity is required and ethanol can be used in regeneration. For lower purities, XAD-16 and GAC yield approximately equal performance. When using ethanol must be avoided, CS16GC offers highest productivity. Copyright © 2011 Elsevier Ltd. All rights reserved.

High resolution crystal structure of rat long chain hydroxy acid oxidase in complex with the inhibitor 4-carboxy-5-[(4-chlorophenyl)sulfanyl]-1, 2, 3-thiadiazole. Implications for inhibitor specificity and drug design

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhi-wei; Vignaud, Caroline; Jaafar, Adil; Lévy, Bernard; Guéritte, Françoise; Guénard, Daniel; Lederer, Florence; Mathews, F. Scott (CNRS-UMR); (WU-MED)

2012-05-24

Long chain hydroxy acid oxidase (LCHAO) is responsible for the formation of methylguanidine, a toxic compound with elevated serum levels in patients with chronic renal failure. Its isozyme glycolate oxidase (GOX), has a role in the formation of oxalate, which can lead to pathological deposits of calcium oxalate, in particular in the disease primary hyperoxaluria. Inhibitors of these two enzymes may have therapeutic value. These enzymes are the only human members of the family of FMN-dependent L-2-hydroxy acid-oxidizing enzymes, with yeast flavocytochrome b{sub 2} (Fcb2) among its well studied members. We screened a chemical library for inhibitors, using in parallel rat LCHAO, human GOX and the Fcb2 flavodehydrogenase domain (FDH). Among the hits was an inhibitor, CCPST, with an IC{sub 50} in the micromolar range for all three enzymes. We report here the crystal structure of a complex between this compound and LCHAO at 1.3 {angstrom} resolution. In comparison with a lower resolution structure of this enzyme, binding of the inhibitor induces a conformational change in part of the TIM barrel loop 4, as well as protonation of the active site histidine. The CCPST interactions are compared with those it forms with human GOX and those formed by two other inhibitors with human GOX and spinach GOX. These compounds differ from CCPST in having the sulfur replaced with a nitrogen in the five-membered ring as well as different hydrophobic substituents. The possible reason for the {approx}100-fold difference in affinity between these two series of inhibitors is discussed. The present results indicate that specificity is an issue in the quest for therapeutic inhibitors of either LCHAO or GOX, but they may give leads for this quest.

Development of an acetic acid tolerant Spathaspora passalidarum strain through evolutionary engineering with resistance to inhibitors compounds of autohydrolysate of Eucalyptus globulus

DEFF Research Database (Denmark)

Morales, Paulina; Gentina, Juan Carlos; Aroca, German

2017-01-01

-fold higher than those obtained with the native strain, respectively. Inhibitors composition present inEucalyptus globulus autohydrolysate were (g L−1): acetic acid, 4.7; furfural, 1.0; HMF, 0.36; formic acid, 0.6;syringaldehyde, 0.14 and vanillin, 0.017. When Eucalyptus globulus autohydrolysate...

Kinetic fractionation of stable nitrogen isotopes during amino acid transamination

International Nuclear Information System (INIS)

Macko, S.A.; Fogel Estep, M.L.; Engel, M.H.; Hare, P.E.

1986-01-01

This study evaluates a kinetic isotope effect involving 15 N, during the transamination reactions catalyzed by glutamic oxalacetic transaminase. During the transfer of amino nitrogen from glutamic acid to oxaloacetate to form aspartic acid, 14 NH 2 reacted 1.0083 times faster than 15 NH 2 . In the reverse reaction transferring NH 2 from aspartic acid to α-ketoglutarate, 14 NH 2 was incorporated 1.0017 times faster than 15 NH 2 . Knowledge of the magnitude and sign of these isotope effects will be useful in the interpretation of the distribution of 15 N in biological and geochemical systems. (author)

Deuterium oxide as a tool for the study of amino acid metabolism

International Nuclear Information System (INIS)

Mitra, R.; Burton, J.; Varner, J.E.

1976-01-01

We have used deuterium oxide in nontoxic concentrations to study, in intact seedlings, the biosynthesis of amino acids. The extent and pattern of deuteration, as determined by a gas--liquid chromatograph--mass spectrometer system, permits conclusions about the biosynthesis of individual amino acids and also about their exposure to transaminases and other enzymes that might introduce deuterium into specific positions of the amino acid by exchange. This method could be used to study amino acid biogenesis in any organism that can tolerate 20 to 40 percent deuterium oxide for a period of a few hours to a few days

[The primary structure of the alpha-amylase inhibitor Hoe 467A from Streptomyces tendae 4158. A new class of inhibitors].

Science.gov (United States)

Aschauer, H; Vértesy, L; Nesemann, G; Braunitzer, G

1983-10-01

The native or modified alpha-amylase inhibitor Hoe 467A - isolated from the culture medium of Streptomyces tendae 4158 - and overlapping peptides were degraded by the automatic Edman technique. The oxidized or aminoethylated or oxidized and maleoylated inhibitor was digested with trypsin and the native inhibitor with pepsin. Further digestion with Staphylococcus aureus proteinase was also carried out. After peptic digestion two cystin peptides were isolated, which allowed the establishment of the disulfide bonds. The alpha-amylase inhibitor is a polypeptid consisting of 74 amino-acid residues with a molecular mass of 7958 Da. The inhibitor is composed of all naturally occurring amino acids except methionine and phenylalanine and shows no sequence homology to known inhibitors. The clinical and pharmacological importance in respect to the inhibitors ability for inactivation of human salivary and pancreatic alpha-amylase is discussed. Especially the proteinase resistance of the inhibitor enables a clinical application in human (e.g. Diabetes mellitus) per os.

Melamine derivatives as effective corrosion inhibitors for mild steel in acidic solution: Chemical, electrochemical, surface and DFT studies

Science.gov (United States)

Verma, Chandrabhan; Haque, J.; Ebenso, Eno E.; Quraishi, M. A.

2018-06-01

In present study two condensation products of melamine (triazine) and glyoxal namely, 2,2-bis(4,6-diamino-1,3,5-triazin-2-ylamino)acetaldehyde (ME-1) and (N2,N2‧E,N2,N2‧E)-N2,N2‧-(ethane-1,2-diylidene)-bis-(1,3,5-triazine-2,4,6-triamine) (ME-2) are tested as mild steel corrosion inhibitors in acidic solution (1M HCl). The inhibition efficiency of ME-1 and ME-2 increases with increase in their concentrations and maximum values of 91.47% and 94.88% were derived, respectively at 100 mgL-1 (34.20 × 10-5 M) concentration. Adsorption of ME-1 and ME-2 on the surface of metal obeyed the Langmuir adsorption isotherm. Polarization investigation revealed that ME-1 and ME-2 act as mixed type inhibitors with minor cathodic prevalence. The chemical and electrochemical analyses also supported by surface characterization methods where significant smoothness in the surface morphologies was observed in the images of SEM and AFM spectra. Several DFT indices such as EHOMO and ELUMO, ΔE, η, σ, χ, μ and ΔN were derived for both ME-1 and ME-2 molecules and correlated with experimental results. The DFT studies have also been carried out for protonated or cationic form of the inhibitor molecules by considering that in acidic medium the heteroatoms of organic inhibitors easily undergo protonation. The experimental and density functional theory (DFT) studies (neutral and protonated) were in good agreement.

Determination of human serum alpha1-acid glycoprotein and albumin binding of various marketed and preclinical kinase inhibitors.

Science.gov (United States)

Zsila, Ferenc; Fitos, Ilona; Bencze, Gyula; Kéri, György; Orfi, László

2009-01-01

There are about 380 protein kinase inhibitors in drug development as of today and 15 drugs have been marketed already for the treatment of cancer. This time 139 validated kinase targets are in the focus of drug research of pharmaceutical companies and big efforts are made for the development of new, druglike kinase inhibitors. Plasma protein binding is an important factor of the ADME profiling of a drug compound. Human serum albumin (HSA) and alpha(1)-acid glycoprotein (AAG) are the most relevant drug carriers in blood plasma. Since previous literature data indicated that AAG is the principal plasma binding component of some kinase inhibitors the present work focuses on the comprehensive evaluation of AAG binding of a series of marketed and experimental kinase inhibitors by using circular dichroism (CD) spectroscopy approach. HSA binding was also evaluated by affinity chromatography. Protein binding interactions of twenty-six kinase inhibitors are characterized. The contribution of AAG and HSA binding data to the pharmacokinetic profiles of the investigated therapeutic agents is discussed. Structural, biological and drug binding properties of AAG as well as the applicability of the CD method in studying drug-protein binding interactions are also briefly reviewed.

Pediatric FAST and elevated liver transaminases: An effective screening tool in blunt abdominal trauma.

Science.gov (United States)

Sola, Juan E; Cheung, Michael C; Yang, Relin; Koslow, Starr; Lanuti, Emma; Seaver, Chris; Neville, Holly L; Schulman, Carl I

2009-11-01

The current standard for the evaluation of children with blunt abdominal trauma (BAT) consists of physical examination, screening lab values, and computed tomography (CT) scan. We sought to determine if the focused assessment with sonography for trauma (FAST) combined with elevated liver transaminases (AST/ALT) could be used as a screening tool for intra-abdominal injury (IAI) in pediatric patients with BAT. Registry data at a level 1 trauma center was retrospectively reviewed from 1991-2007. Data collected on BAT patients under the age of 16 y included demographics, injury mechanism, ISS, GCS, imaging studies, serum ALT and AST levels, and disposition. AST and ALT were considered positive if either one was >100 IU/L. Overall, 3171 cases were identified. A total of 1008 (31.8%) patients received CT scan, 1148 (36.2%) had FAST, and 497 (15.7%) patients received both. Of the 497 patients, 400 (87.1%) also had AST and ALT measured. FAST was 50% sensitive, 91% specific, with a positive predictive value (PPV) of 68%, negative predictive value (NPV) of 83%, and accuracy of 80%. Combining FAST with elevated AST or ALT resulted in a statistically significant increase in all measures (sensitivity 88%, specificity 98%, PPV 94%, NPV 96%, accuracy 96%). FAST combined with AST or ALT > 100 IU/L is an effective screening tool for IAI in children following BAT. Pediatric patients with a negative FAST and liver transaminases < 100 IU/L should be observed rather than subjected to the radiation risk of CT.

Trend analysis of the correlation of amino acid plasma profile with glycemic status in Saudi diabetic patients

Directory of Open Access Journals (Sweden)

Fahad A. Al-Abbasi

2012-10-01

Full Text Available The role of amino acids in diabetes mellitus and its metabolic traits have been suggested previously; however, studied to a very limited scale in the Saudi patient population. Patients diagnosed with diabetes mellitus were included in the current clinical study. Sample was representative and in accordance with the national population distribution. Blood samples were drawn and assayed for glucose, total cholesterol, triglyceride, high density lipoprotein and low density lipoprotein. General biochemical markers, such as alkaline phosphatase (ALP, creatinine kinase (CK, aspartate transaminase (AST, alanine transaminase (ALT and blood urea nitrogen (BUN were assessed. Serum amino acids of different categories (essential, semi-essential and metabolic indicator amino acids were assessed. Correlation co-efficient between each amino acid and serum glucose level was calculated. The current study showed positive correlation between amino acid level and glucose serum concentration in male while it showed negative correlation in female Saudi diabetic patients. Male patients had significantly higher methionine concentration parallel to their glycemic status. Metabolic indicator amino acids significantly changed in concordance with the glycemic status of female patients more than in male patients. In conclusion, serum amino acid is positively correlated with glycemic status in Saudi male diabetic patients while negatively correlated in female patients. Yet, further study would be recommended to utilize serum amino acid profile as surrogate parameter for the metabolic complications of diabetes mellitus.

Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

Energy Technology Data Exchange (ETDEWEB)

Bhat, J. Ishwara [Mangalore Univ., Karnataka (India); Alva, Vijaya D. P. [Shree Devi Institute of Technology, Karnataka (India)

2014-02-15

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum.

Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

International Nuclear Information System (INIS)

Bhat, J. Ishwara; Alva, Vijaya D. P.

2014-01-01

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum

Inhibition of 5-Lipoxygenase inhibitor zileuton in high-fat diet-induced nonalcoholic fatty liver disease progression model

Directory of Open Access Journals (Sweden)

Kuifen Ma

2017-11-01

Full Text Available Objective(s: Arachidonic Acid/5-lipoxygenase (AA/5-LOX pathway connects lipid metabolism and proinflammatory cytokine, which are both related to the development and progression of nonalcoholic fatty liver disease (NAFLD. Therefore, the present study was designed to investigate the role of AA/5-LOX pathway in progression of NAFLD, and the effect of zileuton, an inhibitor of 5-LOX, in this model. Materials and Methods: Animal model for progression of NAFLD was established via feeding high saturated fat diet (HFD. Liver function, HE staining, NAFLD activity score (NAS were used to evaluate NAFLD progression. We detected the lipid metabolism substrates: free fatty acids (FFA and AA, products: cysteinyl-leukotrienes (CysLTs, and changes in gene and protein level of key enzyme in AA/5-LOX pathway including PLA2 and 5-LOX. Furthermore, we determined whether NAFLD progression pathway was delayed or reversed when zileuton (1-[1-(1-benzothiophen-2-ylethyl]-1-hydroxyurea was administrated. Results: Rat model for progression of NAFLD was well established as analyzed by liver transaminase activities, hematoxylin-eosin (HE staining and NAS. The concentrations of substrates and products in AA/5-LOX pathway were increased with the progression of NAFLD. mRNA and protein expression of PLA2 and 5-LOX were all enhanced. Moreover, administration of zileuton inhibited AA/5-LOX pathway and reversed the increased transamine activities and NAS. Conclusion: AA/5-LOX pathway promotes the progression of NAFLD, which can be reversed by zileuton.

Towards a standardized way of reporting physicochemical data and process metrics for transaminase reactions

DEFF Research Database (Denmark)

Tufvesson, Pär; Woodley, John

information about the system and the reaction performance is lacking in the otherwise very useful scientific reports at laboratory scale. For instance, although K equilibrium is one of the key determining factors for the design and scale-up any transaminase process, it is very rarely reported [3]. In order...... to build a broader understanding of the correlation between the underlying physicochemical properties of the system (e.g. substrate volatility) and the process performance (e.g. gram of product per gram of biocatalyst), it would be highly beneficial if these data were reported, and ideally in a consistent...

Biological abatement of cellulase inhibitors

Science.gov (United States)

Bio-abatement uses a fungus to metabolize and remove fermentation inhibitors. To determine whether bio-abatement could alleviate enzyme inhibitor effects observed in biomass liquors after pretreatment, corn stover at 10% (w/v) solids was pretreated with either dilute acid or liquid hot water. The ...

Potent human uric acid transporter 1 inhibitors: in vitro and in vivo metabolism and pharmacokinetic studies

Directory of Open Access Journals (Sweden)

Wempe MF

2012-11-01

Full Text Available Michael F Wempe,1 Janet W Lightner,2 Bettina Miller,1 Timothy J Iwen,1 Peter J Rice,1 Shin Wakui,3 Naohiko Anzai,4 Promsuk Jutabha,4 Hitoshi Endou51Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; 2Department of Pharmacology, East Tennessee State University, Johnson City, TN, USA; 3Department of Toxicology, Azabu University School of Veterinary Medicine, Chuo Sagamihara, Kanagawa, Japan; 4Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu, Shimotsuga, Tochigi, Japan; 5Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, JapanAbstract: Human uric acid transporter 1 (hURAT1; SLC22A12 is a very important urate anion exchanger. Elevated urate levels are known to play a pivotal role in cardiovascular diseases, chronic renal disease, diabetes, and hypertension. Therefore, the development of potent uric acid transport inhibitors may lead to novel therapeutic agents to combat these human diseases. The current study investigates small molecular weight compounds and their ability to inhibit 14C-urate uptake in oocytes expressing hURAT1. Using the most promising drug candidates generated from our structure–activity relationship findings, we subsequently conducted in vitro hepatic metabolism and pharmacokinetic (PK studies in male Sprague-Dawley rats. Compounds were incubated with rat liver microsomes containing cofactors nicotinamide adenine dinucleotide phosphate and uridine 5'-diphosphoglucuronic acid. In vitro metabolism and PK samples were analyzed using liquid chromatography/mass spectrometry-mass spectrometry methods. Independently, six different inhibitors were orally (capsule dosing or intravenously (orbital sinus administered to fasting male Sprague-Dawley rats. Blood samples were collected and analyzed; these data were used to compare in vitro and in vivo metabolism and to

Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

Energy Technology Data Exchange (ETDEWEB)

Rahim, Afidah A. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)]. E-mail: afidah@usm.my; Rocca, E. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Steinmetz, J. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Kassim, M.J. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Adnan, R. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Sani Ibrahim, M. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)

2007-02-15

The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection.

Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

International Nuclear Information System (INIS)

Rahim, Afidah A.; Rocca, E.; Steinmetz, J.; Kassim, M.J.; Adnan, R.; Sani Ibrahim, M.

2007-01-01

The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection

C75, a fatty acid synthase inhibitor, modulates AMP-activated protein kinase to alter neuronal energy metabolism.

Science.gov (United States)

Landree, Leslie E; Hanlon, Andrea L; Strong, David W; Rumbaugh, Gavin; Miller, Ian M; Thupari, Jagan N; Connolly, Erin C; Huganir, Richard L; Richardson, Christine; Witters, Lee A; Kuhajda, Francis P; Ronnett, Gabriele V

2004-01-30

C75, a synthetic inhibitor of fatty acid synthase (FAS), is hypothesized to alter the metabolism of neurons in the hypothalamus that regulate feeding behavior to contribute to the decreased food intake and profound weight loss seen with C75 treatment. In the present study, we characterize the suitability of primary cultures of cortical neurons for studies designed to investigate the consequences of C75 treatment and the alteration of fatty acid metabolism in neurons. We demonstrate that in primary cortical neurons, C75 inhibits FAS activity and stimulates carnitine palmitoyltransferase-1 (CPT-1), consistent with its effects in peripheral tissues. C75 alters neuronal ATP levels and AMP-activated protein kinase (AMPK) activity. Neuronal ATP levels are affected in a biphasic manner with C75 treatment, decreasing initially, followed by a prolonged increase above control levels. Cerulenin, a FAS inhibitor, causes a similar biphasic change in ATP levels, although levels do not exceed control. C75 and cerulenin modulate AMPK phosphorylation and activity. TOFA, an inhibitor of acetyl-CoA carboxylase, increases ATP levels, but does not affect AMPK activity. Several downstream pathways are affected by C75 treatment, including glucose metabolism and acetyl-CoA carboxylase (ACC) phosphorylation. These data demonstrate that C75 modulates the levels of energy intermediates, thus, affecting the energy sensor AMPK. Similar effects in hypothalamic neurons could form the basis for the effects of C75 on feeding behavior.

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...

LBH589, A Hydroxamic Acid-Derived HDAC Inhibitor, is Neuroprotective in Mouse Models of Huntington's Disease.

Science.gov (United States)

Chopra, Vanita; Quinti, Luisa; Khanna, Prarthana; Paganetti, Paolo; Kuhn, Rainer; Young, Anne B; Kazantsev, Aleksey G; Hersch, Steven

2016-12-15

Modulation of gene transcription by HDAC inhibitors has been shown repeatedly to be neuroprotective in cellular, invertebrate, and rodent models of Huntington's disease (HD). It has been difficult to translate these treatments to the clinic, however, because existing compounds have limited potency or brain bioavailability. In the present study, we assessed the therapeutic potential of LBH589, an orally bioavailable hydroxamic acid-derived nonselective HDAC inhibitor in mouse models of HD. The efficacy of LBH589 is tested in two HD mouse models using various biochemical, behavioral and neuropathological outcome measures. We show that LBH589 crosses the blood brain barrier; induces histone hyperacetylation and prevents striatal neuronal shrinkage in R6/2 HD mice. In full-length knock-in HD mice LBH589-treatment improves motor performance and reduces neuronal atrophy. Our efficacious results of LBH589 in fragment and full-length mouse models of HD suggest that LBH589 is a promising candidate for clinical assessment in HD patients and provides confirmation that non-selective HDAC inhibitors can be viable clinical candidates.

Discovery of the first selective inhibitor of excitatory amino acid transporter subtype 1

DEFF Research Database (Denmark)

Jensen, Anders Asbjørn; Erichsen, Mette Navy; Nielsen, Christina Wøhlk

2009-01-01

The discovery of the first class of subtype-selective inhibitors of the human excitatory amino acid transporter subtype 1 (EAAT1) and its rat orthologue GLAST is reported. An opening structure-activity relationship of 25 analogues is presented that addresses the influence of substitutions at the 4......- and 7-positions of the parental skeleton 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile. The most potent analogue 1o displays high nanomolar inhibitory activity at EAAT1 and a >400-fold selectivity over EAAT2 and EAAT3, making it a highly valuable pharmacological tool....

A retinoic acid-inducible mRNA from F9 teratocarcinoma cells encodes a novel protease inhibitor homologue.

Science.gov (United States)

Wang, S Y; Gudas, L J

1990-09-15

We have previously isolated several cDNA clones specific for mRNA species that increase in abundance during the retinoic acid-associated differentiation of F9 teratocarcinoma stem cells. One of these mRNAs, J6, encodes a approximately 40 kDa protein as assayed by hybrid selection and in vitro translation (Wang, S.-Y., LaRosa, G., and Gudas, L. J. (1985) Dev. Biol. 107, 75-86). The time course of J6 mRNA expression is similar to those of both laminin B1 and collagen IV (alpha 1) messages following retinoic acid addition. To address the functional role of this protein, we have isolated a full-length cDNA clone complementary to this approximately 40-kDa protein mRNA. Sequence analysis reveals an open reading frame of 406 amino acids (Mr 45,652). The carboxyl-terminal portion of this predicted protein contains a region that is homologous to the reactive sites found among members of the serpin (serine protease inhibitor) family. The predicted reactive site (P1-P1') of this J6 protein is Arg-Ser, which is the same as that of antithrombin III. Like ovalbumin and human monocyte-derived plasminogen activator inhibitor (mPAI-2), which are members of the serpin gene family, the J6 protein appears to have no typical amino-terminal signal sequence.

Flower inhibition in Kalanchoe blossfeldiana. Bioassay of an endogenous long-day inhibitor and inhibition by (±) abscisic acid and xanthoxin.

Science.gov (United States)

Schwabe, W W

1972-03-01

The inhibition of flowering in Kalanchoe by crude sap expressed from leaves held in non-inductive long-day conditions is described, using a bioassay technique of leaf injection, which confirms the existence of a transferable inhibitor.This technique has also revealed that ± abscisic acid and Xanthoxin are inhibitory to flowering at 50 and 100 ppm respectively. The previously known inhibitory effects of gibberellic acid on flowering have also been confirmed.

Tranexamic acid, an inhibitor of plasminogen activation, reduces urinary collagen cross-link excretion in both experimental and rheumatoid arthritis

NARCIS (Netherlands)

Ronday, H.K.; TeKoppele, J.M.; Greenwald, R.A.; Moak, S.A.; Roos, J.A.D.M. de; Dijkmans, B.A.C.; Breedveld, F.C.; Verheijen, J.H.

1998-01-01

The plasminogen activation system is one of the enzyme systems held responsible for bone and cartilage degradation in rheumatoid arthritis (RA). In this study, we evaluated the effect of tranexamic acid (TEA), an inhibitor of plasminogen activation, on urinary collagen cross-link excretion and

Process Considerations for the Asymmetric Synthesis of Chiral Amines using ω-Transaminase

DEFF Research Database (Denmark)

Lima Afonso Neto, Watson

in order to eliminate infeasible routes. This work illustrates the Laboratory scale characterization of different process options for the asymmetric synthesis of chiral amines catalysed by ω-transaminase (ω –TAm). The studied process options include: (i) the immobilization of the biocatalyst to improve its...... focused on development of comprehensive screening methodologies and guidelines to aid (i) the selection and characterization of suitable biocatalysts for the process; (ii) the selection and characterization of suitable carriers for immobilization of (S)- and (R)-selective ω-TAm; and (iii) the selection...... of suitable polymeric resins for product removal. The work has been performed in collaboration with c-LEcta GmbH (Leipzig, Germany) and DSM Innovative Synthesis (Geleen, The Netherlands) who supplied the enzymes for the case study, making possible the successful demonstration of the screening methodologies...

Binary Mixtures of Nonyl Phenol with Alkyl Substituted Anilines as Corrosion Inhibitors for Mild Steel in Acidic Medium

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H. S. Shukla

2012-01-01

Full Text Available The present study deals with the evaluation of the corrosion inhibition effectiveness of the two binary mixtures of nonyl phenol (NPH with 2, 4 dimethyl aniline (DMA and 2 ethyl aniline (EA at different concentration ratios (from 1:7 to 7:1 for mild steel in H2SO4 (pH=1 solution by weight loss and potentiodynamic polarization method. Corrosion inhibition ability of the compounds has been tested at different exposure periods (6 h to 24 h and at different temperatures (303 K to 333 K. The binary mixture of NPH and EA (at 7:1 concentration ratio has afforded maximum inhibition (IE% 93.5% at 6 h exposure period and at room temperature. The adsorption of both the inhibitors is found to accord with Temkin adsorption isotherm. Potentiodynamic polarization study reveals that the tested inhibitors are mixed type inhibitor and preferentially act on cathodic areas. Electrochemical impedance study suggests formation of an inhibition layer by the adsorption of the inhibitors on the metal surface. An adsorption model of the inhibitor molecules on the metal surface has been proposed after immersion test in the inhibited acid showed characteristic shift of N-H and O-H bond frequencies towards lower side compared to that of the respective pure samples which indicated the donation of electron pair through N and O atom of the inhibitor molecule in the surface adsorption phenomena. SEM study has revealed formation of semi globular inhibitor products on the metal surface. The comparisons of the protection efficiencies of these compounds according to their relative electron density on the adsorption centre and projected molecular area of the inhibitor molecules have been made.

EFFECT OF THIOPROPANOL ON AMINO ACID TURNOVER AND REDOX STATUS IN ALLOXAN DIABETIC RAT LIVER

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Vickram

2016-07-01

Full Text Available BACKGROUND Decreased cellular thiol levels seen in diabetes mellitus (DM may be in part attributed to increased free radical generation. The free radical mediated oxidative stress has been implicated in the pathogenesis of DM and its complications. The relative deficiency or non-availability of insulin in DM affects the metabolism of biomolecules, specifically the carbohydrate metabolism. The insulin-mimicking actions of various thiols have been studied. In our previous study, we have documented that 3-mercapto- 1-propanol (Thiopropanol, a low molecular weight thiol, at the dosage employed has increased glucose utilisation in alloxandiabetic rat liver tissue probably by favouring utilisation of glucose through glycolysis and HMP pathway. It is known that insulin inhibits gluconeogenesis by inhibiting the key enzymes of the same and by controlling the channelling of amino acids for the glucose biosynthesis through gluconeogenic pathway. A study was undertaken to assess the effects of thiopropanol (TP on amino acid turnover and the redox status in alloxan diabetic rat liver. METHODS Male albino rats weighing 150-250 g were used. Diabetes was induced using alloxan monohydrate. Rats were divided into normal and diabetic groups. Levels of amino acid nitrogen (AAN, alanine, total thiol (-SH groups, TBARS (Thiobarbituric acid reactive substances, and activities of alanine transaminase (ALT and aspartate transaminase (AST were estimated in liver specimens of normal, control-alloxan diabetic and TP-exposed-alloxan-diabetic rats. RESULTS The results showed a significant increase (p<0.001 in AAN levels, alanine levels, and total -SH groups concentration; and a significant decrease (p<0.001 in TBARS levels, ALT and AST activities in TP-exposed-alloxan diabetic liver slices as compared to control-alloxan diabetic liver slices. CONCLUSIONS Hence, it may be concluded that TP, at the concentration employed, inhibits gluconeogenesis from amino acids probably by

Physiological and Histopathological Investigations on the Effects of -Lipoic Acid in Rats Exposed to Malathion

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Atef M. Al-Attar

2010-01-01

Full Text Available The present study was designed to evaluate the influence of -lipoic acid treatment in rats exposed to malathion. Forty adult male rats were used in this study and distributed into four groups. Animals of group 1 were untreated and served as control. Rats of group 2 were orally given malathion at a dose level of 100 mg/kg body weight (BW for a period of one month. Experimental animals of group 3 were orally given -lipoic acid at a dose level of 20 mg/kg BW and after 3 hours exposed to malathion at the same dose given to group 2. Rats of group 4 were supplemented with -lipoic acid at the same dose given to group 3. The activities of serum glutamic oxaloacetic acid transaminase (GOT, glutamic pyruvic acid transaminase (GPT, alkaline phosphatase (ALP, and acid phosphatase (ACP, and the values of creatinine, urea, and uric acid were statistically increased, while the values of total protein and total albumin were significantly decreased in rats exposed to malathion. Moreover, administration of malathion for one month resulted in damage of liver and kidney structures. Administration of -lipoic acid before malathion exposure to rat can prevent severe alterations of hematobiochemical parameters and disruptions of liver and kidney structures. In conclusion, this study obviously demonstrated that pretreatment with -lipoic acid significantly attenuated the physiological and histopathological alterations induced by malathion. Also, the present study identifies new areas of research for development of better therapeutic agents for liver, kidney, and other organs' dysfunctions and diseases.

Stabilization versus inhibition of TAFIa by competitive inhibitors in vitro

NARCIS (Netherlands)

Walker, J.B.; Hughes, B.; James, I.; Haddock, P.; Kluft, C.; Bajzar, L.

2003-01-01

Two competitive inhibitors of TAFIa (activated thrombin-activable fibrinolysis inhibitor), 2-guanidinoethyl-mercaptosuccinic acid and potato tuber carboxypeptidase inhibitor, variably affect fibrinolysis of clotted human plasma. Depending on their concentration, the inhibitors shortened, prolonged,

Targeting neuroblastoma stem cells with retinoic acid and proteasome inhibitor.

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Barbara Hämmerle

Full Text Available Neuroblastma cell lines contain a side-population of cells which express stemness markers. These stem-like cells may represent the potential underlying mechanism for resistance to conventional therapy and recurrence of neuroblastoma in patients.To develop novel strategies for targeting the side-population of neurobastomas, we analyzed the effects of 13-cis-retinoic acid (RA combined with the proteasome inhibitor MG132. The short-term action of the treatment was compared with effects after a 5-day recovery period during which both chemicals were withdrawn. RA induced growth arrest and differentiation of SH-SY5Y and SK-N-BE(2 neuroblastoma cell lines. Inhibition of the proteasome caused apoptosis in both cell lines, thus, revealing the critical role of this pathway in the regulated degradation of proteins involved in neuroblastoma proliferation and survival. The combination of RA with MG132 induced apoptosis in a dose-dependent manner, in addition to promoting G2/M arrest in treated cultures. Interestingly, expression of stem cell markers such as Nestin, Sox2, and Oct4 were reduced after the recovery period of combined treatment as compared with untreated cells or treated cells with either compound alone. Consistent with this, neurosphere formation was significantly impaired by the combined treatment of RA and MG132.Given that stem-like cells are associated with resistant to conventional therapy and are thought to be responsible for relapse, our results suggest that dual therapy of RA and proteasome inhibitor might be beneficial for targeting the side-population of cells associated residual disease in high-risk neuroblastoma.

A Mixed-Ligand Approach Enables the Asymmetric Hydrogenation of an α-Isopropylcinnamic Acid en Route to the Renin Inhibitor Aliskiren

NARCIS (Netherlands)

Boogers, Jeroen A.F.; Felfer, Ulfried; Kotthaus, Martina; Lefort, Laurent; Steinbauer, Gerhard; Vries, André H.M. de; Vries, Johannes G. de

2007-01-01

An asymmetric hydrogenation process for an α-isopropyl dihydrocinnamic acid derivative, an intermediate for the renin inhibitor aliskiren, has been developed using a rhodium catalyst ligated with a chiral monodentate phosphoramidite and a nonchiral phosphine. Whereas catalysts based on two

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

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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.

Novel dispersed magnetite core-shell nanogel polymers as corrosion inhibitors for carbon steel in acidic medium

International Nuclear Information System (INIS)

Atta, Ayman M.; El-Azabawy, Olfat E.; Ismail, H.S.; Hegazy, M.A.

2011-01-01

Graphical abstract: Display Omitted Research highlights: → Through a one-step thermal reaction, magnetite nanoparticles were synthesized, and self-assembled mixed films of modified cross-linked ionic polymer magnetite nanoparticles were prepared on iron surface. → The size distribution and shape of magnetite nanoparticles were examined using transmission electron microscopy (TEM). → The corrosion inhibition efficiency of carbon steel in 1 M HCl by the synthesized Fe 3 O 4 nanogel polymers has been studied using potentiodynamic polarization and EIS. → Scanning electron microscopy (SEM) measurements were applied to study the morphology of the carbon steel surface. - Abstract: Novel core-shell preparing poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) and copolymers with acrylic acid (AA) or acrylamide (AM) magnetic nanogels with controllable particle size produced via free aqueous polymerization at room temperature have been developed for the first time. The crosslinking polymerization was carried out in the presence of N,N'-methylenebisacrylamide (MBA) as a crosslinker, N,N,N',N'-tetramethylethylenediamine (TEMED) and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogels were characterized by Fourier transform infrared spectroscopy (FTIR), transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations and temperatures. The results showed the nanogel particles act as mixed inhibitors. Adsorption of nanogel particles was found to fit the Langmuir isotherm and was chemisorption.

Propolis as a green corrosion inhibitor for bronze in weakly acidic solution

Science.gov (United States)

Varvara, Simona; Bostan, Roxana; Bobis, Otilia; Găină, Luiza; Popa, Florin; Mena, Vicente; Souto, Ricardo M.

2017-12-01

In the present work, the inhibitive action of natural propolis on bronze corrosion in a weakly acidic solution containing Na2SO4 and NaHCO3 at pH 5 was evaluated using multiscale electrochemical techniques, namely potentiodynamic polarization, electrochemical impedance spectroscopy and scanning vibrating electrode technique measurements. The major constituents of propolis were identified by HPLC. Surface characterization was performed by SEM-EDX and AFM analysis. Experiments were performed as a function of the propolis concentration and immersion time in the corrosive electrolyte. The obtained results showed that propolis presents good anticorrosive properties on bronze, acting as a mixed-type inhibitor, but its protective effectiveness is time-dependent. The highest inhibiting efficiency of 98.9% was obtained in the presence of 100 ppm propolis, after about 12 h of exposure to inhibitor-containing electrolyte through the stabilization of Cu2O on the bronze surface. The inhibitive properties of propolis on bronze corrosion are likely due to the adsorption of its main constituents (flavonoids and phenolic compounds), through the oxygen atoms in their functional groups and aromatic rings, which have been evidenced by FT-IR spectra. The adsorption of propolis on bronze was found to follow Langmuir adsorption isotherm.

Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions

Energy Technology Data Exchange (ETDEWEB)

Buchweishaija, Joseph

1997-12-31

Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecule with the metallic substrate and how this affects the dissolution rate of the metal. The performance of a commercial amine based fatty acid corrosion inhibitor has been investigated using rotating cylinder electrodes and carbon steel electrodes in CO{sub 2} saturated formation water in the temperature range between 35 to 80{sup o}C. The corrosion process was monitored by electrochemical impedance measurements, and at the end of each experiment full polarization curves were recorded. When the inhibitor was applied on noncorroded electrodes, high inhibitor performance, over 99.7%, was observed independent of temperature. On precorroded electrodes inhibitor performance was found to depend on temperature and time of precorrosion. Above 60{sup o}C, the inhibitor performance decreased with increasing time of precorrosion, presumably because of the formation of a corrosion film of either iron carbonate or a combination of iron carbonate and iron carbide which prevent the inhibitor from reaching the surface. The inhibitor protection efficiency was assumed to be associated with the degree of inhibitor coverage at the material surface, and adsorption isotherms have been calculated in the concentration range between 0.1 ppm and 100 ppm. A Langmuir isotherm was found to give the best fit. The inhibitor performance on a 2 days precorroded rotating electrode was investigated at different solution pH ranging between 4.5 and 6.5 at 35{sup o}C. 130 refs., 80 figs., 22 tabs.

Inhibitor tolerance of a recombinant flocculating industrial Saccharomyces cerevisiae strain during glucose and xylose co-fermentation

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Yun-Cheng Li

Full Text Available ABSTRACT Lignocellulose-derived inhibitors have negative effects on the ethanol fermentation capacity of Saccharomyces cerevisiae. In this study, the effects of eight typical inhibitors, including weak acids, furans, and phenols, on glucose and xylose co-fermentation of the recombinant xylose-fermenting flocculating industrial S. cerevisiae strain NAPX37 were evaluated by batch fermentation. Inhibition on glucose fermentation, not that on xylose fermentation, correlated with delayed cell growth. The weak acids and the phenols showed additive effects. The effect of inhibitors on glucose fermentation was as follows (from strongest to weakest: vanillin > phenol > syringaldehyde > 5-HMF > furfural > levulinic acid > acetic acid > formic acid. The effect of inhibitors on xylose fermentation was as follows (from strongest to weakest: phenol > vanillin > syringaldehyde > furfural > 5-HMF > formic acid > levulinic acid > acetic acid. The NAPX37 strain showed substantial tolerance to typical inhibitors and showed good fermentation characteristics, when a medium with inhibitor cocktail or rape straw hydrolysate was used. This research provides important clues for inhibitors tolerance of recombinant industrial xylose-fermenting S. cerevisiae.

Gallic acid as a corrosion inhibitor of carbon steel in chemical decontamination formulation

International Nuclear Information System (INIS)

Keny, S.J.; Kumbhar, A.G.; Thinaharan, C.; Venkateswaran, G.

2008-01-01

Gallic acid (GA) was found to provide corrosion inhibition to carbon steel (CS) at 4.25 mM concentration. Inherent stability to radiation degradation as compared to other reductant and coupled with its anionic nature with respect to removal using ion exchange column makes it suitable for using as both reductant as well as corrosion inhibitor in dilute decontamination formulations operating in the regenerative mode. A formulation containing CA (1.4 mM), EDTA/NTA (1.4 mM), AA (1.0-2.0 mM) and GA (4.25 mM) was found to be more efficient in dissolving hematite and providing 31% corrosion inhibition (passivation) to the CS

High-resolution bioactivity profiling combined with HPLC-HRMS-SPE-NMR: α-Glucosidase inhibitors and acetylated ellagic acid rhamnosides from Myrcia palustris DC. (Myrtaceae).

Science.gov (United States)

Wubshet, Sileshi G; Moresco, Henrique H; Tahtah, Yousof; Brighente, Inês M C; Staerk, Dan

2015-08-01

Type 2 diabetes (T2D) is an endocrine metabolic disease with a worldwide prevalence of more than 8%, and an expected increase close to 50% in the next 15-20years. T2D is associated with severe and life-threatening complications like retinopathy, neuropathy, nephropathy, and cardiovascular diseases, and therefore improved drug leads or functional foods containing α-glucosidase inhibitors are needed for management of blood glucose. In this study, leaves of Myrcia palustris were investigated by high-resolution α-glucosidase inhibition profiling combined with HPLC-HRMS-SPE-NMR. This led to identification of casuarinin, myricetin 3-O-β-d-(6″-galloyl)galactopyranoside, kaempferol 3-O-β-d-galactopyranoside, myricetin, and quercetin as α-glucosidase inhibitors. In addition, four acetylated ellagic acid rhamnosides, i.e., 4-O-(2″,4″-O-diacetyl-α-l-rhamnopyranosyl)ellagic acid, 4-O-(2″,3″-O-diacetyl-α-l-rhamnopyranosyl)ellagic acid, 4-O-(3″,4″-O-diacetyl-α-l-rhamnopyranosyl)ellagic acid, and 4-O-(2″,3″,4″-O-triacetyl-α-l-rhamnopyranosyl)ellagic acid were identified. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Rapid Selection Procedure for Simple Commercial Implementation of omega-Transaminase Reactions

DEFF Research Database (Denmark)

Gundersen Deslauriers, Maria; Tufvesson, Pär; Rackham, Emma J.

2016-01-01

A stepwise selection procedure is presented to quickly evaluate whether a given omega-transaminase reaction is suitable for a so-called "simple" scale-up for fast industrial implementation. Here "simple" is defined as a system without the need for extensive process development or specialized......, and (3) determination of product inhibition. The method is exemplified with experimental work focused on two products: 1-(4-bromophenyl)ethylamine and (S)-(+)3-amino-1-Boc-piperidine, synthesized from their corresponding pro-chiral ketones each with two alternative amine donors, propan-2-amine, and 1......-phenylethylamine. Each step of the method has a threshold value, which must be surpassed to allow "simple" implementation, helping select suitable combinations of substrates, enzymes, and donors. One reaction pair, 1-Boc-3-piperidone with propan-2-amine, met the criteria of the three-step selection procedure...

Biological abatement of cellulase inhibitors.

Science.gov (United States)

Cao, Guangli; Ximenes, Eduardo; Nichols, Nancy N; Zhang, Leyu; Ladisch, Michael

2013-10-01

Removal of enzyme inhibitors released during lignocellulose pretreatment is essential for economically feasible biofuel production. We tested bio-abatement to mitigate enzyme inhibitor effects observed in corn stover liquors after pretreatment with either dilute acid or liquid hot water at 10% (w/v) solids. Bio-abatement of liquors was followed by enzymatic hydrolysis of cellulose. To distinguish between inhibitor effects on enzymes and recalcitrance of the substrate, pretreated corn stover solids were removed and replaced with 1% (w/v) Solka Floc. Cellulose conversion in the presence of bio-abated liquors from dilute acid pretreatment was 8.6% (0.1x enzyme) and 16% (1x enzyme) higher than control (non-abated) samples. In the presence of bio-abated liquor from liquid hot water pretreated corn stover, 10% (0.1x enzyme) and 13% (1x enzyme) higher cellulose conversion was obtained compared to control. Bio-abatement yielded improved enzyme hydrolysis in the same range as that obtained using a chemical (overliming) method for mitigating inhibitors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Metabolic responses in Candida tropicalis to complex inhibitors during xylitol bioconversion.

Science.gov (United States)

Wang, Shizeng; Li, Hao; Fan, Xiaoguang; Zhang, Jingkun; Tang, Pingwah; Yuan, Qipeng

2015-09-01

During xylitol fermentation, Candida tropicalis is often inhibited by inhibitors in hemicellulose hydrolysate. The mechanisms involved in the metabolic responses to inhibitor stress and the resistances to inhibitors are still not clear. To understand the inhibition mechanisms and the metabolic responses to inhibitors, a GC/MS-based metabolomics approach was performed on C. tropicalis treated with and without complex inhibitors (CI, including furfural, phenol and acetic acid). Partial least squares discriminant analysis was used to determine the metabolic variability between CI-treated groups and control groups, and 25 metabolites were identified as possible entities responsible for the discrimination caused by inhibitors. We found that xylose uptake rate and xylitol oxidation rate were promoted by CI treatment. Metabolomics analysis showed that the flux from xylulose to pentose phosphate pathway increased, and tricarboxylic acid cycle was disturbed by CI. Moreover, the changes in levels of 1,3-propanediol, trehalose, saturated fatty acids and amino acids showed different mechanisms involved in metabolic responses to inhibitor stress. The increase of 1,3-propanediol was considered to be correlated with regulating redox balance and osmoregulation. The increase of trehalose might play a role in protein stabilization and cellular membranes protection. Saturated fatty acids could cause the decrease of membrane fluidity and make the plasma membrane rigid to maintain the integrity of plasma membrane. The deeper understanding of the inhibition mechanisms and the metabolic responses to inhibitors will provide us with more information on the metabolism regulation during xylitol bioconversion and the construction of industrial strains with inhibitor tolerance for better utilization of bioresource. Copyright © 2015 Elsevier Inc. All rights reserved.

Squash inhibitor family of serine proteinases

International Nuclear Information System (INIS)

Otlewski, J.; Krowarsch, D.

1996-01-01

Squash inhibitors of serine proteinases form an uniform family of small proteins. They are built of 27-33 amino-acid residues and cross-linked with three disulfide bridges. The reactive site peptide bond (P1-P1') is between residue 5 (Lys, Arg or Leu) and 6 (always Ile). High resolution X-ray structures are available for two squash inhibitors complexed with trypsin. NMR solution structures have also been determined for free inhibitors. The major structural motif is a distorted, triple-stranded antiparallel beta-sheet. A similar folding motif has been recently found in a number of proteins, including: conotoxins from fish-hunting snails, carboxypeptidase inhibitor from potato, kalata B1 polypeptide, and in some growth factors (e.g. nerve growth factor, transforming growth factor β2, platelet-derived growth factor). Squash inhibitors are highly stable and rigid proteins. They inhibit a number of serine proteinases: trypsin, plasmin, kallikrein, blood clotting factors: X a and XII a , cathepsin G. The inhibition spectrum can be much broadened if specific amino-acid substitutions are introduced, especially at residues which contact proteinase. Squash inhibitors inhibit proteinases via the standard mechanism. According to the mechanism, inhibitors are substrates which exhibit at neutral pH a high k cat /K m index for hydrolysis and resynthesis of the reactive site, and a low value of the hydrolysis constant. (author)

Tranexamic Acid Failed to Reverse the Anticoagulant Effect and Bleeding by an Oral Direct Factor Xa Inhibitor Edoxaban.

Science.gov (United States)

Honda, Yuko; Furugohri, Taketoshi; Morishima, Yoshiyuki

2018-01-01

Agents to reverse the anticoagulant effect of edoxaban, an oral direct factor Xa inhibitor, would be desirable in emergency situations. The aim of this study is to determine the effect of tranexamic acid, an antifibrinolytic agent, on the anticoagulant activity and bleeding by edoxaban in rats. A supratherapeutic dose of edoxaban (3 mg/kg) was intravenously administered to rats. Three minutes after dosing, tranexamic acid (100 mg/kg) was given intravenously. Bleeding was induced by making an incision with a blade on the planta 8 min after edoxaban injection and bleeding time was measured. Prothrombin time (PT) and clot lysis were examined. A supratherapeutic dose of edoxaban significantly prolonged PT and bleeding time. Tranexamic acid did not affect PT or bleeding time prolonged by edoxaban, although tranexamic acid significantly inhibited clot lysis in rat plasma. An antifibrinolytic agent tranexamic acid failed to reverse the anticoagulant effect and bleeding by edoxaban in rats. © 2017 S. Karger AG, Basel.

The use of transcription inhibitors in the study of the mechanism of abscisic acid action in germinating triticale caryopses

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Stanisław Weidner

2014-01-01

Full Text Available The study was conducted on germinating triticale (var. Grado caryopses. The purpose of the experiments was to compare the effect of selected inhibitors of transcription with the action of abscisic acid during germination of caryopses. The following inhibitors were used: α-amanitin, cordycepin, cycloheximide and 5-fluorouracil. Studied were the synthesis of total and polyribosomal RNA, the process of polyribosome formation and the synthesis of ribosomal proteins. The effect of exogenous ABA, especially in the early stages of germination, was not similar to any of the four above inhibitors of transcription. After 12 h of imbibition at a lowered temperature and 3 h of germination, ABA caused a relatively low level of inhibition of RNA synthesis, whereas all of the inhibitors used halted RNA synthesis in embryos by about 50-60%. After 6 h of germination, the same proportion of polyribosomes in the total ribosome fraction (46% was found in both the embryos from the control sample and treated with ABA. The use of inhibitors brought this figure down to below 40%. The conclusion is drawn that in the early stages of germination, regulation of protein synthesis by ABA in triticale caryopses must occur on a level other than transcription.

SGLT2 inhibitor lowers serum uric acid through alteration of uric acid transport activity in renal tubule by increased glycosuria

Science.gov (United States)

Chino, Yukihiro; Samukawa, Yoshishige; Sakai, Soichi; Nakai, Yasuhiro; Yamaguchi, Jun-ichi; Nakanishi, Takeo; Tamai, Ikumi

2014-01-01

Sodium glucose cotransporter 2 (SGLT2) inhibitors have been reported to lower the serum uric acid (SUA) level. To elucidate the mechanism responsible for this reduction, SUA and the urinary excretion rate of uric acid (UEUA) were analysed after the oral administration of luseogliflozin, a SGLT2 inhibitor, to healthy subjects. After dosing, SUA decreased, and a negative correlation was observed between the SUA level and the UEUA, suggesting that SUA decreased as a result of the increase in the UEUA. The increase in UEUA was correlated with an increase in urinary d-glucose excretion, but not with the plasma luseogliflozin concentration. Additionally, in vitro transport experiments showed that luseogliflozin had no direct effect on the transporters involved in renal UA reabsorption. To explain that the increase in UEUA is likely due to glycosuria, the study focused on the facilitative glucose transporter 9 isoform 2 (GLUT9ΔN, SLC2A9b), which is expressed at the apical membrane of the kidney tubular cells and transports both UA and d-glucose. It was observed that the efflux of [14C]UA in Xenopus oocytes expressing the GLUT9 isoform 2 was trans-stimulated by 10 mm d-glucose, a high concentration of glucose that existed under SGLT2 inhibition. On the other hand, the uptake of [14C]UA by oocytes was cis-inhibited by 100 mm d-glucose, a concentration assumed to exist in collecting ducts. In conclusion, it was demonstrated that the UEUA could potentially be increased by luseogliflozin-induced glycosuria, with alterations of UA transport activity because of urinary glucose. PMID:25044127

Characterization of inhibitory effects of the potential therapeutic inhibitors, benzoic acid and pyridine derivatives, on the monophenolase and diphenolase activities of tyrosinase.

Science.gov (United States)

Gheibi, Nematollah; Taherkhani, Negar; Ahmadi, Abolfazl; Haghbeen, Kamahldin; Ilghari, Dariush

2015-02-01

Involvement of tyrosinase in the synthesis of melanin and cell signaling pathway has made it an attractive target in the search for therapeutic inhibitors for treatment of different skin hyperpigmentation disorders and melanoma cancers. In the present study, we conducted a comprehensive kinetic analysis to understand the mechanisms of inhibition imposed by 2-amino benzoic acid, 4-amino benzoic acid, nicotinic acid, and picolinic acid on the monophenolase and diphenolase activities of the mushroom tyrosinase, and then MTT assay was exploited to evaluate their toxicity on the melanoma cells. Kinetic analysis revealed that nicotinic acid and picolinic acid competitively restricted the monophenolase activity with inhibition constants (Ki) of 1.21 mM and 1.97 mM and the diphenolase activity with Kis of 2.4 mM and 2.93 mM, respectively. 2-aminobenzoic acid and 4-aminobenzoic acid inhibited the monophenolase activity in a non-competitive fashion with Kis of 5.15 µM and 3.8 µM and the diphenolase activity with Kis of 4.72 µM and 20 µM, respectively. Our cell-based data revealed that only the pyridine derivatives imposed cytotoxicity in melanoma cells. Importantly, the concentrations of the inhibitors leading to 50% decrease in the cell density (IC50) were comparable to those causing 50% drop in the enzyme activity, implying that the observed cytotoxicity is highly likely due to the tyrosinase inhibition. Moreover, our cell-based data exhibited that the pyridine derivatives acted as anti-proliferative agents, perhaps inducing cytotoxicity in the melanoma cells through inhibition of the tyrosinase activities.

Effect of centrally administered C75, a fatty acid synthase inhibitor, on gastric emptying and gastrointestinal transit in mice.

Science.gov (United States)

Li, Lai-Fu; Lu, Yan-Yu; Xiong, Wei; Liu, Juan-Ying; Chen, Qiang

2008-10-24

The central or systemic administration of 3-carboxy-4-octyl-2-methylenebutyrolactone (C75), a synthetic inhibitor of fatty acid synthase (FAS), causes anorexia and profound weight loss in rodents. The amount of food intake and gastrointestinal mobility are closely related. In this study, an attempt has been made to investigate the effects and mechanisms of C75 on gastric emptying and gastrointestinal transit after intracerebroventricular (i.c.v.) injection in mice. Our data showed that C75 (1, 5, 10 microg/mouse) dose-dependently delayed gastric emptying and gastrointestinal transit in fasted mice. 10 microg C75 delayed gastric emptying by about 21.4% and reduced gastrointestinal transit by about 31.0% compared with vehicle control group. Administration (i.c.v.) of 5-(tetradecyloxy)-2-furoic acid (TOFA, an acetyl-CoA carboxylase (ACC) inhibitor) or ghrelin attenuated the delayed gastrointestinal mobility effect induced by 10 microg C75. Taken together, C75 is able to decrease gastrointestinal mobility and it seems possible that malonyl-CoA and ghrelin might play an intermediary role in these processes.

Saccharomyces cerevisiae Differential Functionalization of Presumed ScALT1 and ScALT2 Alanine Transaminases Has Been Driven by Diversification of Pyridoxal Phosphate Interactions

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Erendira Rojas-Ortega

2018-05-01

Full Text Available Saccharomyces cerevisiae arose from an interspecies hybridization (allopolyploidiza-tion, followed by Whole Genome Duplication. Diversification analysis of ScAlt1/ScAlt2 indicated that while ScAlt1 is an alanine transaminase, ScAlt2 lost this activity, constituting an example in which one of the members of the gene pair lacks the apparent ancestral physiological role. This paper analyzes structural organization and pyridoxal phosphate (PLP binding properties of ScAlt1 and ScAlt2 indicating functional diversification could have determined loss of ScAlt2 alanine transaminase activity and thus its role in alanine metabolism. It was found that ScAlt1 and ScAlt2 are dimeric enzymes harboring 67% identity and intact conservation of the catalytic residues, with very similar structures. However, tertiary structure analysis indicated that ScAlt2 has a more open conformation than that of ScAlt1 so that under physiological conditions, while PLP interaction with ScAlt1 allows the formation of two tautomeric PLP isomers (enolimine and ketoenamine ScAlt2 preferentially forms the ketoenamine PLP tautomer, indicating a modified polarity of the active sites which affect the interaction of PLP with these proteins, that could result in lack of alanine transaminase activity in ScAlt2. The fact that ScAlt2 forms a catalytically active Schiff base with PLP and its position in an independent clade in “sensu strictu” yeasts suggests this protein has a yet undiscovered physiological function.

Saccharomyces cerevisiae Differential Functionalization of Presumed ScALT1 and ScALT2 Alanine Transaminases Has Been Driven by Diversification of Pyridoxal Phosphate Interactions

Science.gov (United States)

Rojas-Ortega, Erendira; Aguirre-López, Beatriz; Reyes-Vivas, Horacio; González-Andrade, Martín; Campero-Basaldúa, Jose C.; Pardo, Juan P.; González, Alicia

2018-01-01

Saccharomyces cerevisiae arose from an interspecies hybridization (allopolyploidiza-tion), followed by Whole Genome Duplication. Diversification analysis of ScAlt1/ScAlt2 indicated that while ScAlt1 is an alanine transaminase, ScAlt2 lost this activity, constituting an example in which one of the members of the gene pair lacks the apparent ancestral physiological role. This paper analyzes structural organization and pyridoxal phosphate (PLP) binding properties of ScAlt1 and ScAlt2 indicating functional diversification could have determined loss of ScAlt2 alanine transaminase activity and thus its role in alanine metabolism. It was found that ScAlt1 and ScAlt2 are dimeric enzymes harboring 67% identity and intact conservation of the catalytic residues, with very similar structures. However, tertiary structure analysis indicated that ScAlt2 has a more open conformation than that of ScAlt1 so that under physiological conditions, while PLP interaction with ScAlt1 allows the formation of two tautomeric PLP isomers (enolimine and ketoenamine) ScAlt2 preferentially forms the ketoenamine PLP tautomer, indicating a modified polarity of the active sites which affect the interaction of PLP with these proteins, that could result in lack of alanine transaminase activity in ScAlt2. The fact that ScAlt2 forms a catalytically active Schiff base with PLP and its position in an independent clade in “sensu strictu” yeasts suggests this protein has a yet undiscovered physiological function. PMID:29867852

Herbs as new type of green inhibitors for acidic corrosion of steel

Energy Technology Data Exchange (ETDEWEB)

Khamis, E. [Faculty of Science, Chemistry Department, Alexandria University, P.O. Box 426 Ibrahimia Alexandria 21321 (Egypt); AlAndis, N. [College of Science, Chemistry Department, King Saud University (Saudi Arabia)

2002-09-01

Corrosion inhibition of steel in sulphuric acid by six different herb plants has been studied using a.c and d.c electrochemical techniques. The environmentally friendly investigated compounds are namely: thyme, coriander, hibiscus, anis, black cumin and Garden cress. Electrochemical impedance spectroscopy has been successfully used to evaluate the performance of these compounds. The ac measurements showed that the dissolution process is activation controlled. Bode and theta diagrams show only one time constant ({tau}). Potentiodynamic polarization curves indicate that the studied compounds are mixed-type inhibitors. The order of increasing inhibition efficiency was correlated with the change of the constituent active materials of the compounds. Thyme, which contains the powerful antiseptic thymol as the active ingredient, offers excellent protection for steel surface. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

Development of Cholinesterase Inhibitors Using (a)-Lipoic Acid-benzyl Piperazine Hybrid Molecules

International Nuclear Information System (INIS)

Kim, Beomcheol; Lee, Seunghwan; Jang, Mi; Shon, Min Young; Park, Jeong Ho

2013-01-01

A series of hybrid molecules between (α)-lipoic acid (ALA) and benzyl piperazines were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory activities were evaluated. Even though the parent compounds did not show any inhibitory activity against cholinesterase (ChE), all hybrid molecules showed BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, ALA-1-(3-methylbenzyl)piperazine (15) was shown to be an effective inhibitor of both BuChE (IC 50 = 2.3 ± 0.7 μM) and AChE (IC 50 = 30.31 ± 0.64 μM). An inhibition kinetic study using compound 15 indicated a mixed inhibition type. Its binding affinity (K i ) value to BuChE is 2.91 ± 0.15 μM

Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

OpenAIRE

R. Khandelwal; S. K. Arora; S. P. Mathur

2011-01-01

The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to in...

Cathepsin D inhibitors

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M. Gacko

2007-11-01

Full Text Available Inhibitors of cathepsin D belong to chemical compounds that estrify carboxyl groups of the Asp33 and Asp231residues of its catalytic site, penta-peptides containing statin, i.e. the amino acid similar in structure to the tetraedric indirectproduct, and polypeptides found in the spare organs of many plants and forming permanent noncovalent complexes withcathepsin. Cathepsin D activity is also inhibited by alpha2-macroglobulin and antibodies directed against this enzyme.Methods used to determine the activity and concentration of these inhibitors and their analytical, preparative and therapeuticapplications are discussed.

Extra Virgin Olive Oil Reduced Polyunsaturated Fatty Acid and Cholesterol Oxidation in Rodent Liver: Is This Accounted for Hydroxytyrosol-Fatty Acid Conjugation?

Science.gov (United States)

Lee, Yiu Yiu; Crauste, Céline; Wang, Hualin; Leung, Ho Hang; Vercauteren, Joseph; Galano, Jean-Marie; Oger, Camille; Durand, Thierry; Wan, Jennifer Man-Fan; Lee, Jetty Chung-Yung

2016-10-17

The effects of extra virgin olive oil (EVOO) and carbon tetrachloride (CCl 4 ) induced oxidative stress in rats were determined by the generation of isoprostanoids. These are known to be robust biomarkers to evaluate nonenzymatic and free radical related oxidation. Other oxidative stress biomarkers such as hydroxyeicosatetraenoic acid products (HETEs) and cholesterol oxidation products (COPs) were also determined. The rodents received a control diet, high-fat diet (20% w/w) composed of extra virgin olive oil (EVOO), corn oil (CO), or lard, and high-fat diets with CCl 4 insult throughout the experimental period. The EVOO diet was found to suppress the formation of isoprostanoids and COPs compared to that of the control. EVOO also had a high total phenolic content and antioxidant activity compared to those of CO and lard and may be contributed to by the hydroxytyrosol component conjugated to fatty acids (HT-FA). This is the first study to identify HT-FA in EVOO, and it was 4-fold higher than that of olive oil, whereas none was found in corn oil. Furthermore, the EVOO diet showed reduced liver lipid vesicles in CCl 4 treated rats compared to that of the control. However, liver toxicity measurements of AST (aspartate transaminase) and ALT (alanine transaminase) activities showed augmentation with CCl 4 treatment but were not alleviated by the diets given. Our findings suggest that EVOO is a daily functional food capable of enhancing the antioxidant system for liver protection; the effect is potentially attributed to the phenolic and lipophenolic (phenol conjugated by fatty acids) content.

Anomalous inhibition of c-Met by the kinesin inhibitor aurintricarboxylic acid.

Science.gov (United States)

Milanovic, Mina; Radtke, Simone; Peel, Nick; Howell, Michael; Carrière, Virginie; Joffre, Carine; Kermorgant, Stéphanie; Parker, Peter J

2012-03-01

c-Met [the hepatocyte growth factor (HGF) receptor] is a receptor tyrosine kinase playing a role in various biological events. Overexpression of the receptor has been observed in a number of cancers, correlating with increased metastatic tendency and poor prognosis. Additionally, activating mutations in c-Met kinase domain have been reported in a subset of familial cancers causing resistance to treatment. Receptor trafficking, relying on the integrity of the microtubule network, plays an important role in activation of downstream targets and initiation of signalling events. Aurintricarboxylic acid (ATA) is a triphenylmethane derivative that has been reported to inhibit microtubule motor proteins kinesins. Additional reported properties of this inhibitor include inhibition of protein tyrosine phosphatases, nucleases and members of the Jak family. Here we demonstrate that ATA prevents HGF-induced c-Met phosphorylation, internalisation, subsequent receptor trafficking and degradation. In addition, ATA prevented HGF-induced downstream signalling which also affected cellular function, as assayed by collective cell migration of A549 cells. Surprisingly, the inhibitory effect of ATA on HGF-induced phosphorylation and signalling in vivo was associated with an increase in basal c-Met kinase activity in vitro. It is concluded that the inhibitory effects of ATA on c-Met in vivo is an allosteric effect mediated through the kinase domain of the receptor. As the currently tested adenosine triphosphate competitive tyrosine kinase inhibitors (TKIs) may lead to tumor resistance (McDermott U, et al., Cancer Res 2010;70:1625-34), our findings suggest that novel anti-c-Met therapies could be developed in the future for cancer treatment. Copyright © 2011 UICC.

Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors.

Science.gov (United States)

Hassan, Refat M; Zaafarany, Ishaq A

2013-06-17

Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyeletrolyte pectates (PEC) as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper.

Characterization of inhibitory effects of the potential therapeutic inhibitors, benzoic acid and pyridine derivatives, on the monophenolase and diphenolase activities of tyrosinase

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Nematollah Gheibi

2015-02-01

Full Text Available Objective(s:Involvement of tyrosinase in the synthesis of melanin and cell signaling pathway has made it an attractive target in the search for therapeutic inhibitors for treatment of different skin hyperpigmentation disorders and melanoma cancers. Materials and Methods: In the present study, we conducted a comprehensive kinetic analysis to understand the mechanisms of inhibition imposed by 2-amino benzoic acid, 4-amino benzoic acid, nicotinic acid, and picolinic acid on the monophenolase and diphenolase activities of the mushroom tyrosinase, and then MTT assay was exploited to evaluate their toxicity on the melanoma cells. Results: Kinetic analysis revealed that nicotinic acid and picolinic acid competitively restricted the monophenolase activity with inhibition constants (Ki of 1.21 mM and 1.97 mM and the diphenolase activity with Kis of 2.4 mM and 2.93 mM, respectively. 2-aminobenzoic acid and 4-aminobenzoic acid inhibited the monophenolase activity in a non-competitive fashion with Kis of 5.15 µM and 3.8 µM and the diphenolase activity with Kis of 4.72 µM and 20 µM, respectively. Conclusion: Our cell-based data revealed that only the pyridine derivatives imposed cytotoxicity in melanoma cells. Importantly, the concentrations of the inhibitors leading to 50% decrease in the cell density (IC50 werecomparable to those causing 50% drop in the enzyme activity, implying that the observed cytotoxicity is highly likely due to the tyrosinase inhibition. Moreover, our cell-based data exhibited that the pyridine derivatives acted as anti-proliferative agents, perhaps inducing cytotoxicity in the melanoma cells through inhibition of the tyrosinase activities.

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.

Silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases-Novel noncompetitive α-glucosidase inhibitors.

Science.gov (United States)

Zheng, Jingwei; Ma, Lin

2015-01-01

A series of silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases were designed and tested for α-glucosidase inhibition. Our results indicate that all the silver complexes (4a-18a) possessed strong inhibitory activity at μmolL(-1) level, especially glutamine (12a) and histidine (18a) Schiff base silver(I) complexes exhibited an IC50 value of less than 0.01μmolL(-1). This series of compounds exhibited noncompetitive inhibition characteristics in kinetic studies. In addition, we investigated the mechanism of inhibition and the structure-activity relationships of the amino acid Schiff base silver complexes. Our results reveal that Schiff base silver complexes may be explored for their therapeutic potential as alternatives of α-glucosidase inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of fermentation inhibitors in the presence and absence of activated charcoal on the growth of Saccharomyces cerevisiae.

Science.gov (United States)

Kim, Sung-Koo; Park, Don-Hee; Song, Se Hee; Wee, Young-Jung; Jeong, Gwi-Taek

2013-06-01

The acidic hydrolysis of biomass generates numerous inhibitors of fermentation, which adversely affect cell growth and metabolism. The goal of the present study was to determine the effects of fermentation inhibitors on growth and glucose consumption by Saccharomyces cerevisiae. We also conducted in situ adsorption during cell cultivation in synthetic broth containing fermentation inhibitors. In order to evaluate the effect of in situ adsorption on cell growth, five inhibitors, namely 5-hydroxymethylfurfural, levulinic acid, furfural, formic acid, and acetic acid, were introduced into synthetic broth. The existence of fermentation inhibitors during cell culture adversely affects cell growth and sugar consumption. Furfural, formic acid, and acetic acid were the most potent inhibitors in our culture system. The in situ adsorption of inhibitors by the addition of activated charcoal to the synthetic broth increased cell growth and sugar consumption. Our results indicate that detoxification of fermentation media by in situ adsorption may be useful for enhancing biofuel production.

Purification, characterization and cloning of an aspartic proteinase inhibitor from squash phloem exudate.

Science.gov (United States)

Christeller, J T; Farley, P C; Ramsay, R J; Sullivan, P A; Laing, W A

1998-05-15

Phloem exudate from squash fruit contains heat-inactivated material which inhibits pepsin activity. This inhibitory activity was purified by mild acid treatment, chromatography on trypsin-agarose, Sephadex G-75 and reverse-phase HPLC, resulting in the elution of three peaks with pepsin-inhibitory activity. N-terminal sequencing indicated a common sequence of MGPGPAIGEVIG and the presence of minor species with seven- or two-amino-acid N-terminal extensions beyond this point. Microheterogeneity in this end sequence was exhibited within and between two preparations. Internal sequencing of a major peak after a trypsin digestion gave the sequence FYNVVVLEK. The common N-terminal sequence was used to design a degenerate primer for 3' rapid amplification of cDNA ends and cDNA clones encoding two isoforms of the inhibitor were obtained. The open reading frames of both cDNAs encoded proteins (96% identical) which contained the experimentally determined internal sequence. The amino acid content calculated from the predicted amino acid sequence was very similar to that measured by amino acid analysis of the purified inhibitor. The two predicted amino acid sequences (96 residues) had neither similarity to any other aspartic proteinase inhibitor nor similarity to any other protein. The inhibitors have a molecular mass of 10,552 Da, measured by matrix-assisted laser-desorption ionisation time-of-flight mass spectrometry and approximately 10,000 Da by SDS/PAGE, and behave as dimers of approximately 21,000 Da during chromatography on Superdex G-75 gel-filtration medium. The calculated molecular masses from the predicted amino acid sequences were 10,551 Da and 10,527 Da. The inhibitor was capable of inhibiting pepsin (Ki = 2 nM) and a secreted aspartic proteinase from the fungus Glomerella cingulata (Ki = 20 nM). The inhibitor, which is stable over acid and neutral pH, has been named squash aspartic proteinase inhibitor (SQAPI).

Amine donor and acceptor influence on the thermodynamics of ω-transaminase reactions

DEFF Research Database (Denmark)

Gundersen, Maria T.; Abu, Rohana; Schürmann, Martin

2015-01-01

In recent years biocatalytic transamination using ω-transaminase has become established as one of the most interesting routes to synthesize chiral amines with a high enantiomeric purity, especially in the pharmaceutical sector where the demand for such compounds is high. Nevertheless, one limitat...... of such reactions because it may be used to help select suitable donor/acceptor combinations. The results presented here give guidance, with respect to thermodynamics, in order to further extend the application of biocatalytic transamination....... limitation for successful implementation and scale-up is that the thermodynamics of such conversions are frequently found unfavourable. Herein we report experimental measurements of apparent equilibrium constants for several industrially relevant transamination reactions in a systematic manner to better...... understand the effect of amine acceptor and donor choice. For example, we have found that ortho-substitution of acetophenone like molecules, had a significant impact on the thermodynamic equilibrium. Likewise, the effect of cyclic amine acceptors was evaluated and compared to similar non-cyclic structures...

Utilization of Boron Compounds for the Modification of Suberoyl Anilide Hydroxamic Acid as Inhibitor of Histone Deacetylase Class II Homo sapiens

Science.gov (United States)

Bakri, Ridla; Parikesit, Arli Aditya; Satriyanto, Cipta Prio; Kerami, Djati; Tambunan, Usman Sumo Friend

2014-01-01

Histone deacetylase (HDAC) has a critical function in regulating gene expression. The inhibition of HDAC has developed as an interesting anticancer research area that targets biological processes such as cell cycle, apoptosis, and cell differentiation. In this study, an HDAC inhibitor that is available commercially, suberoyl anilide hydroxamic acid (SAHA), has been modified to improve its efficacy and reduce the side effects of the compound. Hydrophobic cap and zinc-binding group of these compounds were substituted with boron-based compounds, whereas the linker region was substituted with p-aminobenzoic acid. The molecular docking analysis resulted in 8 ligands with ΔG binding value more negative than the standards, SAHA and trichostatin A (TSA). That ligands were analyzed based on the nature of QSAR, pharmacological properties, and ADME-Tox. It is conducted to obtain a potent inhibitor of HDAC class II Homo sapiens. The screening process result gave one best ligand, Nova2 (513246-99-6), which was then further studied by molecular dynamics simulations. PMID:25214833

Pharmacokinetics, pharmacodynamics, and tolerability of verinurad, a selective uric acid reabsorption inhibitor, in healthy adult male subjects

Directory of Open Access Journals (Sweden)

Shen Z

2017-07-01

Full Text Available Zancong Shen,1 Michael Gillen,2 Jeffrey N Miner,1 Gail Bucci,1 David M Wilson,1 Jesse W Hall1 1Ardea Biosciences, Inc., San Diego, CA, 2AstraZeneca, Gaithersburg, MD, USA Purpose: Verinurad (RDEA3170 is a selective uric acid reabsorption inhibitor in clinical development for the treatment of gout and asymptomatic hyperuricemia. The aim of this study was to evaluate the pharmacokinetics, pharmacodynamics, and tolerability of verinurad in healthy adult males.Subjects and methods: This was a Phase I, randomized, double-blind, placebo-controlled, single and multiple ascending dose study. Panels of eight male subjects received a single oral dose of verinurad or placebo in either a fasted or fed state; panels of 10–12 male subjects received ascending doses of once-daily verinurad or placebo in a fasted state for 10 days. Serial blood and urine samples were assayed for verinurad and uric acid. Safety was assessed by adverse event (AE reports, laboratory tests, vital signs, and electrocardiograms (ECGs.Results: A total of 81 adult males completed the study. Following single doses of verinurad, maximum observed plasma concentration (Cmax and area under the plasma concentration–time curve (AUC increased in a dose-proportional manner; Cmax occurred at 0.5–0.75 hours and 1.25 hours in the fasted and fed states, respectively. Food decreased AUC by 23% and Cmax by 37%-53%. There was a modest accumulation of verinurad following multiple daily doses. Verinurad reduced serum urate levels by up to 62% (40 mg, single dose and 61% (10 mg, multiple dose. The increase in urinary excretion of uric acid was greatest in the first 6 hours after dosing and was still evident ≥24 hours for verinurad doses ≥2 mg. Verinurad was well tolerated at all doses. No serious AEs, severe AEs, discontinuations due to AEs, or clinically significant laboratory or ECG abnormalities were reported.Conclusion: Single and multiple doses of verinurad were well tolerated

Metal complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid and benzohydroxamic acid. Crystal and molecular structure of [Cu(phen)2(Cl)]Cl x H2Sha, a model for a peroxidase-inhibitor complex.

Science.gov (United States)

O'Brien, E C; Farkas, E; Gil, M J; Fitzgerald, D; Castineras, A; Nolan, K B

2000-04-01

Stability constants of iron(III), copper(II), nickel(II) and zinc(II) complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid (HAha) and benzohydroxamic acid (HBha) have been determined at 25.0 degrees C, I=0.2 mol dm(-3) KCl in aqueous solution. The complex stability order, iron(III) > copper(II) > nickel(II) approximately = zinc(II) was observed whilst complexes of H2Sha were found to be more stable than those of the other two ligands. In the preparation of ternary metal ion complexes of these ligands and 1,10-phenanthroline (phen) the crystalline complex [Cu(phen)2(Cl)]Cl x H2Sha was obtained and its crystal structure determined. This complex is a model for hydroxamate-peroxidase inhibitor interactions.

The tricarboxylic acid cycle activity in cultured primary astrocytes is strongly accelerated by the protein tyrosine kinase inhibitor tyrphostin 23

DEFF Research Database (Denmark)

Hohnholt, Michaela C; Blumrich, Eva-Maria; Waagepetersen, Helle S

2017-01-01

production. In addition, T23-treatment strongly increased the molecular carbon labeling of the TCA cycle intermediates citrate, succinate, fumarate and malate, and significantly increased the incorporation of (13)C-labelling into the amino acids glutamate, glutamine and aspartate. These results clearly......Tyrphostin 23 (T23) is a well-known inhibitor of protein tyrosine kinases and has been considered as potential anti-cancer drug. T23 was recently reported to acutely stimulate the glycolytic flux in primary cultured astrocytes. To investigate whether T23 also affects the tricarboxylic acid (TCA...

Proliferation related acidic leucine-rich protein PAL31 functions as a caspase-3 inhibitor

International Nuclear Information System (INIS)

Sun Weiyong; Kimura, Hiromichi; Hattori, Naka; Tanaka, Satoshi; Matsuyama, Shigemi; Shiota, Kunio

2006-01-01

Proliferation related acidic leucine-rich protein PAL31 (PAL31) is expressed in proliferating cells and consists of 272 amino acids with a tandem structure of leucine-rich repeats in the N-terminus and a highly acidic region with a putative nuclear localization signal in the C-terminus. We previously reported that PAL31 is required for cell cycle progression. In the present study, we found that the antisense oligonucleotide of PAL31 induced apoptosis to the transfected Nb2 cells. Stable transfectants, in which PAL31 was regulated by an inducible promoter, were generated to gain further insight into the signaling role of PAL31 in the regulation of apoptosis. Expression of PAL31 resulted in the marked rescue of Rat1 cells from etoposide and UV radiation-induced apoptosis and the cytoprotection was correlated with the levels of PAL31 protein. Thus, cytoprotection from apoptosis is a physiological function of PAL31. PAL31 can suppress caspase-3 activity but not cytochrome c release in vitro, indicating that PAL31 is a direct caspase-3 inhibitor. In conclusion, PAL31 is a multifunctional protein working as a cell cycle progression factor as well as a cell survival factor

Okadaic Acid, a Bioactive Fatty Acid from Halichondria okadai, Stimulates Lipolysis in Rat Adipocytes: The Pivotal Role of Perilipin Translocation

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Nen-Chung Chang

2013-01-01

Full Text Available Lipid metabolism in visceral fat cells is correlated with metabolic syndrome and cardiovascular diseases. Okadaic-acid, a 38-carbon fatty acid isolated from the black sponge Halichondria okadai, can stimulate lipolysis by promoting the phosphorylation of several proteins in adipocytes. However, the mechanism of okadaic acid-induced lipolysis and the effects of okadaic acid on lipid-droplet-associated proteins (perilipins and beta-actin remain unclear. We isolated adipocytes from rat epididymal fat pads and treated them with isoproterenol and/or okadaic acid to estimate lipolysis by measuring glycerol release. Incubating adipocytes with okadaic acid stimulated time-dependent lipolysis. Lipid-droplet-associated perilipins and beta-actin were analyzed by immunoblotting and immunofluorescence, and the association of perilipin A and B was found to be decreased in response to isoproterenol or okadaic acid treatment. Moreover, okadaic-acid treatment could enhance isoproterenol-mediated lipolysis, whereas treatment of several inhibitors such as KT-5720 (PKA inhibitor, calphostin C (PKC inhibitor, or KT-5823 (PKG inhibitor did not attenuate okadaic-acid-induced lipolysis. By contrast, vanadyl acetylacetonate (tyrosine phosphatase inhibitor blocked okadaic-acid-dependent lipolysis. These results suggest that okadaic acid induces the phosphorylation and detachment of lipid-droplet-associated perilipin A and B from the lipid droplet surface and thereby leads to accelerated lipolysis.

GABA transaminases from Saccharomyces cerevisiae and Arabidopsis thaliana complement function in cytosol and mitochondria.

Science.gov (United States)

Cao, Juxiang; Barbosa, Jose M; Singh, Narendra; Locy, Robert D

2013-07-01

GABA transaminase (GABA-T) catalyses the conversion of GABA to succinate semialdehyde (SSA) in the GABA shunt pathway. The GABA-T from Saccharomyces cerevisiae (ScGABA-TKG) is an α-ketoglutarate-dependent enzyme encoded by the UGA1 gene, while higher plant GABA-T is a pyruvate/glyoxylate-dependent enzyme encoded by POP2 in Arabidopsis thaliana (AtGABA-T). The GABA-T from A. thaliana is localized in mitochondria and mediated by an 18-amino acid N-terminal mitochondrial targeting peptide predicated by both web-based utilities TargetP 1.1 and PSORT. Yeast UGA1 appears to lack a mitochondrial targeting peptide and is localized in the cytosol. To verify this bioinformatic analysis and examine the significance of ScGABA-TKG and AtGABA-T compartmentation and substrate specificity on physiological function, expression vectors were constructed to modify both ScGABA-TKG and AtGABA-T, so that they express in yeast mitochondria and cytosol. Physiological function was evaluated by complementing yeast ScGABA-TKG deletion mutant Δuga1 with AtGABA-T or ScGABA-TKG targeted to the cytosol or mitochondria for the phenotypes of GABA growth defect, thermosensitivity and heat-induced production of reactive oxygen species (ROS). This study demonstrates that AtGABA-T is functionally interchangeable with ScGABA-TKG for GABA growth, thermotolerance and limiting production of ROS, regardless of location in mitochondria or cytosol of yeast cells, but AtGABA-T is about half as efficient in doing so as ScGABA-TKG. These results are consistent with the hypothesis that pyruvate/glyoxylate-limited production of NADPH mediates the effect of the GABA shunt in moderating heat stress in Saccharomyces. Copyright © 2013 John Wiley & Sons, Ltd.

Avaliação dos níveis das transaminases dos pacientes com infecção pelo Plasmodium vivax atendidos em um centro de referência para tratamento da malária no Estado de Mato Grosso

Directory of Open Access Journals (Sweden)

Elisane de Freitas Pereira

2017-11-01

Full Text Available Objetivo: Analisar os marcadores hepáticos (transaminases em pacientes com malária causada pelo Plasmodium vivax. Métodos: Trata-se de um estudo transversal retrospectivo, incluindo pacientes que apresentaram monoinfecção pelo P. vivax. O teste de Mann-Whitney U ou o teste t de Student foram utilizados para comparar a atividade média das transaminases de acordo com a classificação clínica e epidemiológica do paciente infectado. O teste de Kruskal-Wallis foi utilizado para comparar a média da atividade das transaminases de acordo com a classificação da infecção. Valores de p<0,05 foram considerados significativos. Resultados: Indivíduos menores de 7 anos apresentaram maior atividade da transaminase glutâmico oxalacética (TGO e da transaminase glutâmico pirúvica (TGP — respectivamente, 68,7 U/L e 79,8 U/L — em relação a pacientes com idade de 8 a 59 anos (TGO 29,8 U/L e TGP 39,2 U/L e acima de 60 anos (TGO 32,5 U/L e TGP 34 U/L. A média da dosagem sérica de TGO de todos os pacientes incluídos no estudo foi de 31,99 U/L e de TGP foi de 41,1 U/L. A atividade de TGP nos pacientes primoinfectados foi maior que nos reinfectados ou com recaída, sendo 65,6 U/L contra 36,2 U/L e 32,7 U/L, respectivamente. Conclusão: Crianças apresentam maior atividade de transaminases que os indivíduos maiores de sete anos de idade. Pacientes com infecção prévia pelo P. vivax apresentam menores valores séricos da atividade das transaminases do que os primoinfectados. Indivíduos com episódios de recaída apresentam menores valores das enzimas avaliadas do que aqueles com reinfecção ou primoinfecção.

Development of Cholinesterase Inhibitors Using (a)-Lipoic Acid-benzyl Piperazine Hybrid Molecules

Energy Technology Data Exchange (ETDEWEB)

Kim, Beomcheol; Lee, Seunghwan; Jang, Mi; Shon, Min Young; Park, Jeong Ho [Hanbat National Univ., Daejeon (Korea, Republic of)

2013-11-15

A series of hybrid molecules between (α)-lipoic acid (ALA) and benzyl piperazines were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory activities were evaluated. Even though the parent compounds did not show any inhibitory activity against cholinesterase (ChE), all hybrid molecules showed BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, ALA-1-(3-methylbenzyl)piperazine (15) was shown to be an effective inhibitor of both BuChE (IC{sub 50} = 2.3 ± 0.7 μM) and AChE (IC{sub 50} = 30.31 ± 0.64 μM). An inhibition kinetic study using compound 15 indicated a mixed inhibition type. Its binding affinity (K{sub i}) value to BuChE is 2.91 ± 0.15 μM.

Characterisation of (R-2-(2-Fluorobiphenyl-4-yl-N-(3-Methylpyridin-2-ylPropanamide as a Dual Fatty Acid Amide Hydrolase: Cyclooxygenase Inhibitor.

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Sandra Gouveia-Figueira

Full Text Available Increased endocannabinoid tonus by dual-action fatty acid amide hydrolase (FAAH and substrate selective cyclooxygenase (COX-2 inhibitors is a promising approach for pain-relief. One such compound with this profile is 2-(2-fluorobiphenyl-4-yl-N-(3-methylpyridin-2-ylpropanamide (Flu-AM1. These activities are shown by Flu-AM1 racemate, but it is not known whether its two single enantiomers behave differently, as is the case towards COX-2 for the parent flurbiprofen enantiomers. Further, the effects of the compound upon COX-2-derived lipids in intact cells are not known.COX inhibition was determined using an oxygraphic method with arachidonic acid and 2-arachidonoylglycerol (2-AG as substrates. FAAH was assayed in mouse brain homogenates using anandamide (AEA as substrate. Lipidomic analysis was conducted in unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Both enantiomers inhibited COX-2 in a substrate-selective and time-dependent manner, with IC50 values in the absence of a preincubation phase of: (R-Flu-AM1, COX-1 (arachidonic acid 6 μM; COX-2 (arachidonic acid 20 μM; COX-2 (2-AG 1 μM; (S-Flu-AM1, COX-1 (arachidonic acid 3 μM; COX-2 (arachidonic acid 10 μM; COX-2 (2-AG 0.7 μM. The compounds showed no enantiomeric selectivity in their FAAH inhibitory properties. (R-Flu-AM1 (10 μM greatly inhibited the production of prostaglandin D2 and E2 in both unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Levels of 2-AG were not affected either by (R-Flu-AM1 or by 10 μM flurbiprofen, either alone or in combination with the FAAH inhibitor URB597 (1 μM.Both enantiomers of Flu-AM1 are more potent inhibitors of 2-AG compared to arachidonic acid oxygenation by COX-2. Inhibition of COX in lipopolysaccharide + interferon γ- stimulated RAW 264.7 cells is insufficient to affect 2-AG levels despite the large induction of COX-2 produced by this treatment.

Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors

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Refat M. Hassan

2013-06-01

Full Text Available Corrosion inhibition of aluminum (Al in hydrochloric acid by anionic polyeletrolyte pectates (PEC as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper.

PENGHAMBAT α AMILASE: JENIS, SUMBER, DAN POTENSI PEMANFAATANNYA DALAM KESEHATAN [α Amylase Inhibitors: Types, Sources, and Their Potential Utilization for Health Purposes

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Budiasih Wahyuntari

2011-12-01

Full Text Available SUMMARYAlpha amylase inhibitors affect carbohydrate metabolism in digestive system. The inhibitors induce carbohydrate tolerance, fullness and prolonging gastric emptying that might be used to aid in diabetic and obesity treatment. There are two types of α- amylase inhibitors, proteinaceous and non-proteinaceous ones. Proteinaceous inhibitor is classified into seven classes including legumes, lectin, knottin, cereal, Kunitz, -thionin and thaumatin types. Plant proteinaceous inhibitors are present in cereals and legumes. Some non-proteinaceous inhibitors include flavonid, polyphenols, organic acid that might be produced by microbes or extracted from plants such as acarbose, saponin dan cardiac glycoside, gallic acid, proto-catechuic acid, caffeic acid, ellagic acid, ferulic acid, quercetin hibiscus acid and α-, β- and γ-cyclodextrin.

Effect of the scale inhibitor on ion content in reverse osmosis system for seawater desalination

Science.gov (United States)

Gao, Yuhua; Liu, Zhenfa; Zhang, Lihui; Li, Haihua

2017-09-01

A scale inhibitor was synthesized from polysuccinimide with 2-aminoethanesulfonic acid and aspartic acid. The effect of scale inhibitor on ion content in reverse osmosis system for seawater desalination was studied. The results showed that the ion content of permeate water is lower with the scale inhibitor added in RO system for seawater desalination than without scale inhibitor. On the contrary, the ion content of concentrate water is higher when with scale inhibitor in RO system.

Effects of amino acid supplementations on metabolic and physiological parameters in Atlantic cod (Gadus morhua) under stress.

Science.gov (United States)

Herrera, Marcelino; Herves, María Antonia; Giráldez, Inmaculada; Skar, Kristin; Mogren, Hanne; Mortensen, Atle; Puvanendran, Velmurugu

2017-04-01

The effects of tryptophan (Trp) and phenylalanine (Phe) diet supplementation on the stress and metabolism of the Atlantic cod have been studied. Fish were fed diet supplemented with Trp or Phe or control diet for 1 week. At the end of the feeding trial, fish were subjected to air exposure or heat shock. Following samples of blood, liver and muscle were taken from the fish and were analyzed for stress and metabolic indicators. After an air exposure, plasma cortisol levels in fish fed with Trp and Phe diets were lower compared to the fish fed the control diet. Diets containing both amino acids increased significantly the liver transaminase activities in juvenile cod. During thermal stress, high Trp contents had significant effects on fructose biphosphatase activity though Phe did not. Overall, activities of glucose 6-phosphate dehydrogenase, pyruvate kinase, and phosphofructokinase increased significantly for both amino acid diets. For the thermal stress, fish had the highest values of those activities for the 3Trp diet. Trp content in the diet had significant effects on the transaminase activity in muscle during air stress compared to fish fed control and Phe diets. Muscle alanine transaminase activity for thermal stress in fish fed any diet was not significantly different from the control. Both Trp and Phe supplementations reduced the stress markers in the cod; hence, they could be used as additives for the stress attenuation. However, they also raised the activity of key enzymes in glycolysis and gluconeogenesis, mainly the Trp diets.

The tyrosine kinase inhibitor imatinib mesylate suppresses uric acid crystal-induced acute gouty arthritis in mice.

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Laurent L Reber

Full Text Available Gouty arthritis is caused by the deposition of monosodium urate (MSU crystals in joints. Despite many treatment options for gout, there is a substantial need for alternative treatments for patients unresponsive to current therapies. Tyrosine kinase inhibitors have demonstrated therapeutic benefit in experimental models of antibody-dependent arthritis and in rheumatoid arthritis in humans, but to date, the potential effects of such inhibitors on gouty arthritis has not been evaluated. Here we demonstrate that treatment with the tyrosine kinase inhibitor imatinib mesylate (imatinib can suppress inflammation induced by injection of MSU crystals into subcutaneous air pouches or into the ankle joint of wild type mice. Moreover, imatinib treatment also largely abolished the lower levels of inflammation which developed in IL-1R1-/- or KitW-sh/W-sh mice, indicating that this drug can inhibit IL-1-independent pathways, as well as mast cell-independent pathways, contributing to pathology in this model. Imatinib treatment not only prevented ankle swelling and synovial inflammation when administered before MSU crystals but also diminished these features when administrated after the injection of MSU crystals, a therapeutic protocol more closely mimicking the clinical situation in which treatment occurs after the development of an acute gout flare. Finally, we also assessed the efficiency of local intra-articular injections of imatinib-loaded poly(lactic-co-glycolic acid (PLGA nanoparticles in this model of acute gout. Treatment with low doses of this long-acting imatinib:PLGA formulation was able to reduce ankle swelling in a therapeutic protocol. Altogether, these results raise the possibility that tyrosine kinase inhibitors might have utility in the treatment of acute gout in humans.

Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

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Marko Chigondo

2016-01-01

Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

Glucagon-like peptide-1 7-36 amide and peptide YY from the L-cell of the ileal mucosa are potent inhibitors of vagally induced gastric acid secretion in man

DEFF Research Database (Denmark)

Wettergren, A; Petersen, H; Orskov, C

1994-01-01

BACKGROUND: Glucagon-like peptide (GLP-1) 7-36 amide and peptide YY (PYY) from the L-cell of the ileal mucosa are potent inhibitors of gastric acid secretion in man. It is not clear, however, by which mechanism(s) they inhibit acid secretion. In dogs the inhibitory effect of PYY on acid secretion...

Lansoprazole and carbonic anhydrase IX inhibitors sinergize against human melanoma cells.

Science.gov (United States)

Federici, Cristina; Lugini, Luana; Marino, Maria Lucia; Carta, Fabrizio; Iessi, Elisabetta; Azzarito, Tommaso; Supuran, Claudiu T; Fais, Stefano

2016-01-01

Proton Pump Inhibitors (PPIs) reduce tumor acidity and therefore resistance of tumors to drugs. Carbonic Anhydrase IX (CA IX) inhibitors have proven to be effective against tumors, while tumor acidity might impair their full effectiveness. To analyze the effect of PPI/CA IX inhibitors combined treatment against human melanoma cells. The combination of Lansoprazole (LAN) and CA IX inhibitors (FC9-399A and S4) has been investigated in terms of cell proliferation inhibition and cell death in human melanoma cells. The combination of these inhibitors was more effective than the single treatments in both inhibiting cell proliferation and in inducing cell death in human melanoma cells. These results represent the first successful attempt in combining two different proton exchanger inhibitors. This is the first evidence on the effectiveness of a new approach against tumors based on the combination of PPI and CA IX inhibitors, thus providing an alternative strategy against tumors.

Experimental and quantum chemical studies on two triazole derivatives as corrosion inhibitors for mild steel in acid media

Energy Technology Data Exchange (ETDEWEB)

Li, W.; Tian, H.; Hou, B. [Key Laboratory of Corrosion Science, Shandong, Institute of Oceanology, Chinese Academy of Sciences, Qingdao (China); Hu, L.; Tao, Z. [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

2011-11-15

Two triazole derivatives [1-phenyl-2-(5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadizaol-2-ylsulphanyl)-ethanone (PTOE) and 2-(4-tert-butyl-benzylsulphanyl)-5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadiazole (TBTO)] were synthesized as new corrosion inhibitors for the corrosion of mild steel in 1 M hydrochloric acid solutions. The inhibiting efficiency of the different inhibitors was evaluated by means of weight loss and electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and polarization curves. The electrochemical investigation results indicate that these compounds act as mixed-type inhibitors retarding the anodic and cathodic corrosion reactions and do not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The studied compounds followed the Langmuir adsorption isotherm, and the thermodynamic parameters were determined and discussed. The effect of molecular structure on the inhibition efficiency has been investigated with ab initio calculations. The electronic properties such as highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, dipole moment ({mu}) and molecular orbital densities were calculated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Modulation of hypericin photodynamic therapy by pretreatment with 12 various inhibitors of arachidonic acid metabolism in colon adenocarcinoma HT-29 cells

Czech Academy of Sciences Publication Activity Database

Kleban, J.; Mikeš, J.; Szilárdiová, B.; Koval, J.; Sačková, V.; Solár, P.; Horváth, Viktor; Hofmanová, Jiřina; Kozubík, Alois; Fedoročko, P.

2007-01-01

Roč. 83, č. 5 (2007), s. 1174-1185 ISSN 0031-8655 R&D Projects: GA AV ČR(CZ) 1QS500040507 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : hypericin * photodynamic therapy * arachidonic acid inhibitors Subject RIV: BO - Biophysics Impact factor: 2.172, year: 2007

Aromatic inhibitors derived from ammonia-pretreated lignocellulose hinder bacterial ethanologenesis by activating regulatory circuits controlling inhibitor efflux and detoxification

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David H. Keating

2014-08-01

Full Text Available Efficient microbial conversion of lignocellulosic hydrolysates to biofuels is a key barrier to the economically viable deployment of lignocellulosic biofuels. A chief contributor to this barrier is the impact on microbial processes and energy metabolism of lignocellulose-derived inhibitors, including phenolic carboxylates, phenolic amides (for ammonia-pretreated biomass, phenolic aldehydes, and furfurals. To understand the bacterial pathways induced by inhibitors present in ammonia-pretreated biomass hydrolysates, which are less well studied than acid-pretreated biomass hydrolysates, we developed and exploited synthetic mimics of ammonia-pretreated corn stover hydrolysate (ACSH. To determine regulatory responses to the inhibitors normally present in ACSH, we measured transcript and protein levels in an Escherichia coli ethanologen using RNA-seq and quantitative proteomics during fermentation to ethanol of synthetic hydrolysates containing or lacking the inhibitors. Our study identified four major regulators mediating these responses, the MarA/SoxS/Rob network, AaeR, FrmR, and YqhC. Induction of these regulons was correlated with a reduced rate of ethanol production, buildup of pyruvate, depletion of ATP and NAD(PH, and an inhibition of xylose conversion. The aromatic aldehyde inhibitor 5-hydroxymethylfurfural appeared to be reduced to its alcohol form by the ethanologen during fermentation, whereas phenolic acid and amide inhibitors were not metabolized. Together, our findings establish that the major regulatory responses to lignocellulose-derived inhibitors are mediated by transcriptional rather than translational regulators, suggest that energy consumed for inhibitor efflux and detoxification may limit biofuel production, and identify a network of regulators for future synthetic biology efforts.

Discovery of a New Class of Sortase A Transpeptidase Inhibitors to Tackle Gram-Positive Pathogens: 2-(2-Phenylhydrazinylidenealkanoic Acids and Related Derivatives

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Benedetta Maggio

2016-02-01

Full Text Available A FRET-based random screening assay was used to generate hit compounds as sortase A inhibitors that allowed us to identify ethyl 3-oxo-2-(2-phenylhydrazinylidenebutanoate as an example of a new class of sortase A inhibitors. Other analogues were generated by changing the ethoxycarbonyl function for a carboxy, cyano or amide group, or introducing substituents in the phenyl ring of the ester and acid derivatives. The most active derivative found was 3-oxo-2-(2-(3,4dichlorophenylhydrazinylidenebutanoic acid (2b, showing an IC50 value of 50 µM. For a preliminary assessment of their antivirulence properties the new derivatives were tested for their antibiofilm activity. The most active compound resulted 2a, which showed inhibition of about 60% against S. aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538 and S. epidermidis RP62A at a screening concentration of 100 µM.

Ursodeoxycholic Acid in Treatment of Non-cholestatic Liver Diseases: A Systematic Review.

Science.gov (United States)

Reardon, Jillian; Hussaini, Trana; Alsahafi, Majid; Azalgara, Vladimir Marquez; Erb, Siegfried R; Partovi, Nilufar; Yoshida, Eric M

2016-09-28

Aims: To systematically evaluate the literature for evidence to support the use of bile acids in non-cholestatic liver conditions. Methods: Searches were conducted on the databases of Medline (1948-March 31, 2015), Embase (1980-March 31, 2015) and the Cochrane Central Register of Controlled Trials, and on Google and Google Scholar to identify articles describing ursodeoxycholic acid (UDCA) and its derivatives for non-cholestatic hepatic indications. Combinations of the following search terms were used: ursodeoxycholic acid, ursodiol, bile acids and/or salts, non alcoholic fatty liver, non alcoholic steatohepatitis, fatty liver, alcoholic hepatitis, alcohol, liver disease, autoimmune, autoimmune hepatitis, liver transplant, liver graft, transplant rejection, graft rejection, ischemic reperfusion injury, reperfusion injury, hepatitis B, hepatitis C, viral hepatitis, chronic hepatitis, acute hepatitis, transaminases, alanine transaminase, liver enzymes, aspartate aminotransferase, gamma-glutamyl transferase, gamma-glutamyl transpeptidase, bilirubin, alkaline phosphatase. No search limits were applied. Additionally, references of the included studies were reviewed to identify additional articles. Results: The literature search yielded articles meeting inclusion criteria for the following indications: non-alcoholic fatty liver disease (n = 5); alcoholic liver disease (n = 2); autoimmune hepatitis (n = 6), liver transplant (n = 2) and viral hepatitis (n = 9). Bile acid use was associated with improved normalization of liver biochemistry in non-alcoholic fatty liver disease, autoimmune hepatitis and hepatitis B and C infections. In contrast, liver biochemistry normalization was inconsistent in alcoholic liver disease and liver transplantation. The majority of studies reviewed showed that normalization of liver biochemistry did not correlate to improvement in histologic disease. In the prospective trials reviewed, adverse effects associated with the bile acids were limited

Ursodeoxycholic acid for nonalcoholic steatohepatitis.

Science.gov (United States)

Wu, Sheng-di; Li, Lei; Wang, Ji-yao

2012-11-01

The aim of this study was to evaluate the effects of ursodeoxycholic acid on patients with nonalcoholic steatohepatitis using meta-analysis. PubMed, EMBASE, Web of Science, Cochrane Library, Chinese Biomedical Databases, and article references were searched. We included randomized controlled trials using liver biopsy as a reference standard. We identified three eligible studies. Among histological responses, only lobular inflammation improved in the high-dose ursodeoxycholic acid subgroup compared with the control group [mean deviation (MD): -0.23 (-0.40, -0.06), P=0.008]. However, fibrosis may tend to increase [MD: 0.08 (-0.04, 0.20), P=0.17]. Among biochemical responses, γ-glutamyl transpeptidase reduction was significantly greater in the ursodeoxycholic acid group than in the placebo group, and the reduction tendency was only shown in the high-dose subgroup [MD: -35.58 (-52.60, -18.56), Pursodeoxycholic acid subgroup compared with the control group [MD: 0.43 (0.14, 0.72), P=0.004]. Ursodeoxycholic acid-treated patients did not differ significantly from control patients with regard to alanine transaminase, aspartate aminotransferase, and alkaline phosphatase activities. Adverse events were nonspecific and considered of no major clinical relevance. Ursodeoxycholic acid in monotherapy has no substantial positive effect on nonalcoholic steatohepatitis.

Amino acid derivatives are substrates or non-transported inhibitors of the amino acid transporter PAT2 (slc36a2).

Science.gov (United States)

Edwards, Noel; Anderson, Catriona M H; Gatfield, Kelly M; Jevons, Mark P; Ganapathy, Vadivel; Thwaites, David T

2011-01-01

The H(+)-coupled amino acid transporter PAT2 (SLC36A2) transports the amino acids proline, glycine, alanine and hydroxyproline. A physiological role played by PAT2 in amino acid reabsorption in the renal proximal tubule is demonstrated by mutations in SLC36A2 that lead to an iminoglycinuric phenotype (imino acid and glycine uria) in humans. A number of proline, GABA and tryptophan derivatives were examined to determine if they function either as transported substrates or non-transported inhibitors of PAT2. The compounds were investigated following heterologous expression of rat PAT2 in Xenopus laevis oocytes. PAT2 function was characterised by: radiotracer uptake and competition (cis-inhibition) studies; radiotracer efflux and trans-stimulation; and measurement of substrate-induced positive inward current by two-electrode voltage-clamp. In general, the proline derivatives appeared to be transported substrates and the relative ability to induce current flow was closely related to the inhibitory effects on PAT2-mediated l-[(3)H]proline uptake. In contrast, certain heterocyclic GABA derivatives (e.g. l-pipecolic acid) were translocated only slowly. Finally, the tryptophan derivatives inhibited PAT2 function but did not undergo transport. l-Proline uptake was inhibited by 5-hydroxy-l-tryptophan (IC(50) 1.6±0.4mM), α-methyl-d,l-tryptophan (3.5±1.5mM), l-tryptophan, 1-methyl-l-tryptophan and indole-3-propionic acid. Although neither 5-hydroxy-l-tryptophan nor α-methyl-d,l-tryptophan were able to elicit inward current in PAT2-expressing oocytes both reduced the current evoked by l-proline. 5-Hydroxy-l-tryptophan and α-methyl-d,l-tryptophan were unable to trans-stimulate l-proline efflux from PAT2-expressing oocytes, confirming that the two compounds act as non-transported blockers of PAT2. These two tryptophan derivatives should prove valuable experimental tools in future investigations of the physiological roles of PAT2. Copyright © 2010 Elsevier B.V. All rights

Computational study of molecular electrostatic potential, docking and dynamics simulations of gallic acid derivatives as ABL inhibitors.

Science.gov (United States)

Raghi, K R; Sherin, D R; Saumya, M J; Arun, P S; Sobha, V N; Manojkumar, T K

2018-04-05

Chronic myeloid leukemia (CML), a hematological malignancy arises due to the spontaneous fusion of the BCR and ABL gene, resulting in a constitutively active tyrosine kinase (BCR-ABL). Pharmacological activity of Gallic acid and 1,3,4-Oxadiazole as potential inhibitors of ABL kinase has already been reported. Objective of this study is to evaluate the ABL kinase inhibitory activity of derivatives of Gallic acid fused with 1,3,4-Oxadiazole moieties. Attempts have been made to identify the key structural features responsible for drug likeness of the Gallic acid and the 1,3,4-Oxadiazole ring using molecular electrostatic potential maps (MESP). To investigate the inhibitory activity of Gallic acid derivatives towards the ABL receptor, we have applied molecular docking and molecular dynamics (MD) simulation approaches. A comparative study was performed using Bosutinib as the standard which is an approved CML drug acting on the same receptor. Furthermore, the novel compounds designed and reported here in were evaluated for ADME properties and the results indicate that they show acceptable pharmacokinetic properties. Accordingly these compounds are predicted to be drug like with low toxicity potential. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

Transamination of branched chain amino acids (BCAA) in rat adipose tissue

Energy Technology Data Exchange (ETDEWEB)

Frick, G.P.; Goodman, H.M.

1986-03-05

Like most extrahepatic tissues, adipose tissue can transaminate the BCAA faster than they are oxidized. Catabolism of the BCAA by adipose tissue appears to be limited by the activity of branched chain ..cap alpha..-keto acid dehydrogenase (BCDH). Conditions which stimulate the activity of this intramitochondrial enzyme in tissue extracts also increase the rate at which (1-/sup 14/C)leucine (L) and (1-/sup 14/C)valine (V) are oxidized by tissue segments. However, when maximum rates of oxidation were measured, 10 mM L was oxidized to /sup 14/CO/sub 2/ 5 times faster than 10 mM V (30 +/- 2 vs. 6 +/- 1 nmol min/sup -1/ g tis/sup -1/). In contrast, the ..cap alpha..-keto analogs of L and V were oxidized by tissue segments at nearly equal rates which slightly exceeded the rate of L oxidation. These results suggested that transamination might limit the catabolism of V, perhaps due to its inaccessibility to transaminase. The distribution of transaminase activity in tissue extracts was determined after centrifugation to obtain mitochondrial and cytosolic fractions. L and V were transaminated at similar rates by enzymes in both fractions. Transaminase activity in the mitochondrial fraction was greater than that of the cytosol and exceeded the capacity of the tissue to oxidize L. Catabolism of BCAA may depend upon intramitochondrial transamination and oxidation of V may be slower than that of L because uptake of V by mitochondria may be slower than that of L.

Transamination of branched chain amino acids (BCAA) in rat adipose tissue

International Nuclear Information System (INIS)

Frick, G.P.; Goodman, H.M.

1986-01-01

Like most extrahepatic tissues, adipose tissue can transaminate the BCAA faster than they are oxidized. Catabolism of the BCAA by adipose tissue appears to be limited by the activity of branched chain α-keto acid dehydrogenase (BCDH). Conditions which stimulate the activity of this intramitochondrial enzyme in tissue extracts also increase the rate at which [1- 14 C]leucine (L) and [1- 14 C]valine (V) are oxidized by tissue segments. However, when maximum rates of oxidation were measured, 10 mM L was oxidized to 14 CO 2 5 times faster than 10 mM V (30 +/- 2 vs. 6 +/- 1 nmol min -1 g tis -1 ). In contrast, the α-keto analogs of L and V were oxidized by tissue segments at nearly equal rates which slightly exceeded the rate of L oxidation. These results suggested that transamination might limit the catabolism of V, perhaps due to its inaccessibility to transaminase. The distribution of transaminase activity in tissue extracts was determined after centrifugation to obtain mitochondrial and cytosolic fractions. L and V were transaminated at similar rates by enzymes in both fractions. Transaminase activity in the mitochondrial fraction was greater than that of the cytosol and exceeded the capacity of the tissue to oxidize L. Catabolism of BCAA may depend upon intramitochondrial transamination and oxidation of V may be slower than that of L because uptake of V by mitochondria may be slower than that of L

Benzimidazole as corrosion inhibitor for heat treated 6061 Al- SiCp composite in acetic acid

International Nuclear Information System (INIS)

Chacko, Melby; Nayak, Jagannath

2015-01-01

6061 Al-SiCpcomposite was solutionizedat 350 °C for 30 minutes and water quenched. It was then underaged at 140 °C (T6 treatment). The aging behaviour of the composite was studied using Rockwell B hardness measurement. Corrosion behaviour of the underaged sample was studied in different concentrations of acetic acid and at different temperatures. Benzimidazole at different concentrations was used for the inhibition studies. Inhibition efficiency of benzimidazole was calculated for different experimental conditions. Thermodynamic parameters were found out which suggested benzimidazole is an efficient inhibitor and it adsorbed on to the surface of composite by mixed adsorption where chemisorption is predominant. (paper)

Autophagic dedifferentiation induced by cooperation between TOR inhibitor and retinoic acid signals in budding tunicates.

Science.gov (United States)

Kawamura, Kaz; Yoshida, Takuto; Sekida, Satoko

2018-01-15

Asexual bud development in the budding tunicate Polyandrocarpa misakiensis involves transdifferentiation of multipotent epithelial cells, which is triggered by retinoic acid (RA), and thrives under starvation after bud isolation from the parent. This study aimed to determine cell and molecular mechanisms of dedifferentiation that occur during the early stage of transdifferentiation. During dedifferentiation, the numbers of autophagosomes, lysosomes, and secondary lysosomes increased remarkably. Mitochondrial degradation and exosome discharge also occurred in the atrial epithelium. Autophagy-related gene 7 (Atg7) and lysosomal proton pump A gene (PumpA) were activated during the dedifferentiation stage. When target of rapamycin (TOR) inhibitor was administered to growing buds without isolating them from the parent, phagosomes and secondary lysosomes became prominent. TOR inhibitor induced Atg7 only in the presence of RA. In contrast, when growing buds were treated with RA, lysosomes, secondary lysosomes, and mitochondrial degradation were prematurely induced. RA significantly activated PumpA in a retinoid X receptor-dependent manner. Our results indicate that in P. misakiensis, TOR inhibition and RA signals act in synergy to accomplish cytoplasmic clearance for dedifferentiation. Copyright © 2017 Elsevier Inc. All rights reserved.

Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

Energy Technology Data Exchange (ETDEWEB)

Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

2009-12-19

The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

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

Histone deacetylase inhibitors (HDACIs: multitargeted anticancer agents

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Ververis K

2013-02-01

Full Text Available Katherine Ververis,1 Alison Hiong,1 Tom C Karagiannis,1,* Paul V Licciardi2,*1Epigenomic Medicine, Alfred Medical Research and Education Precinct, 2Allergy and Immune Disorders, Murdoch Childrens Research Institute, Melbourne, VIC, Australia*These authors contributed equally to this workAbstract: Histone deacetylase (HDAC inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza and depsipeptide (romidepsin, Istodax. More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the

High throughput in vivo protease inhibitor selection platform

DEFF Research Database (Denmark)

2017-01-01

The invention relates to a recombinant microbial cell comprising a selection platform for screening for a protease inhibitor, wherein the platform comprises transgenes encoding a protease having selective peptide bond cleavage activity at a recognition site amino acid sequence; and transgenes...... platform for screening for a protease inhibitor....

A case study on robust optimal experimental design for model calibration of ω-Transaminase

DEFF Research Database (Denmark)

Daele, Timothy, Van; Van Hauwermeiren, Daan; Ringborg, Rolf Hoffmeyer

the experimental space. However, it is expected that more informative experiments can be designed to increase the confidence of the parameter estimates. Therefore, we apply Optimal Experimental Design (OED) to the calibrated model of Shin and Kim (1998). The total number of samples was retained to allow fair......” parameter values are not known before finishing the model calibration. However, it is important that the chosen parameter values are close to the real parameter values, otherwise the OED can possibly yield non-informative experiments. To counter this problem, one can use robust OED. The idea of robust OED......Proper calibration of models describing enzyme kinetics can be quite challenging. This is especially the case for more complex models like transaminase models (Shin and Kim, 1998). The latter fitted model parameters, but the confidence on the parameter estimation was not derived. Hence...

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.

An Updated Review of Tyrosinase Inhibitors

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Te-Sheng Chang

2009-05-01

Full Text Available Tyrosinase is a multifunctional, glycosylated, and copper-containing oxidase, which catalyzes the first two steps in mammalian melanogenesis and is responsible for enzymatic browning reactions in damaged fruits during post-harvest handling and processing. Neither hyperpigmentation in human skin nor enzymatic browning in fruits are desirable. These phenomena have encouraged researchers to seek new potent tyrosinase inhibitors for use in foods and cosmetics. This article surveys tyrosinase inhibitors newly discovered from natural and synthetic sources. The inhibitory strength is compared with that of a standard inhibitor, kojic acid, and their inhibitory mechanisms are discussed.

Toxic effects on bioaccumulation and hematological parameters of juvenile rockfish Sebastes schlegelii exposed to dietary lead (Pb) and ascorbic acid.

Science.gov (United States)

Kim, Jun-Hwan; Kang, Ju-Chan

2017-06-01

Juvenile rockfish, Sebastes schlegelii (mean length 11.3 ± 1.2 cm, and mean weight 32.5 ± 4.1 g) were exposed for four weeks to dietary lead (Pb 2+ ) at 0, 120, and 240 mg/L and ascorbic acid (AsA) at 100, 200, and 400 mg/L. The exposure concentrations and duration of significant Pb-induced accumulations in specific tissues of S. schlegelii were assessed. High levels of ascorbic acid significantly attenuated accumulations following exposure to dietary Pb. Dietary Pb exposure caused a significant increase in blood Pb concentrations, whereas red blood cell (RBC) count, hematocrit, and hemoglobin were significantly decreased. Notable changes were also observed in plasma calcium, magnesium, glucose, cholesterol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvate transaminase (GPT). The growth performance of S. schlegelii was significantly decreased. High doses AsA supplemention were effective in attenuating the changes brought about by dietary Pb exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Semisynthesis and Structure-Activity Studies of Uncarinic Acid C Isolated from Uncaria rhynchophylla as a Specific Inhibitor of the Nucleation Phase in Amyloid β42 Aggregation.

Science.gov (United States)

Yoshioka, Takuya; Murakami, Kazuma; Ido, Kyohei; Hanaki, Mizuho; Yamaguchi, Kanoko; Midorikawa, Satohiro; Taniwaki, Shinji; Gunji, Hiroki; Irie, Kazuhiro

2016-10-28

Oligomers of the 42-mer amyloid-β protein (Aβ42), rather than fibrils, cause synaptic dysfunction in the pathology of Alzheimer's disease (AD). The nucleation phase in a nucleation-dependent aggregation model of Aβ42 is related to the formation of oligomers. Uncaria rhynchophylla is one component of "Yokukansan", a Kampo medicine, which is widely used for treating AD symptoms. Previously, an extract of U. rhynchophylla was found to reduce the aggregation of Aβ42, but its active principles have yet to be identified. In the present work, uncarinic acid C (3) was identified as an inhibitor of Aβ42 aggregation that is present in U. rhynchophylla. Moreover, compound 3 acted as a specific inhibitor of the nucleation phase of Aβ42 aggregation. Compound 3 was synthesized from saponin A (10), an abundant byproduct of rutin purified from Uncaria elliptica. Comprehensive structure-activity studies on 3 suggest that both a C-27 ferulate and a C-28 carboxylic acid group are required for its inhibitory activity. These findings may aid the development of oligomer-specific inhibitors for AD therapy.

The acidity of the tumor microenvironment is a mechanism of immune escape that can be overcome by proton pump inhibitors

Science.gov (United States)

Bellone, Matteo; Calcinotto, Arianna; Filipazzi, Paola; De Milito, Angelo; Fais, Stefano; Rivoltini, Licia

2013-01-01

We have recently reported that lowering the pH to values that are frequently detected in tumors causes reversible anergy in both human and mouse CD8+ T lymphocytes in vitro. The same occurs in vivo, in the tumor microenvironment and the administration of proton pump inhibitors, which buffer tumor acidity, can revert T-cell anergy and increase the efficacy of immunotherapy. PMID:23483769

The Role of Ursodeoxycholic Acid in Acute Viral Hepatitis: an Evidence-based Case Report.

Science.gov (United States)

Wijaya, Indra

2015-10-01

to review the role of ursodeoxycholic acid in acute viral hepatitis. following literature searching according to the clinical question on Pubmed and Cochrane Library. After filtered with our inclusion and exclusion criteria, one meta-analysis and two randomized clinical trials are obtained. Through critical appraisal, it was concluded that the articles meet the criteria for validity and relevance. the article found that there is a positive effect of ursodeoxycholic acid on the activity of serum transaminases and cholestasis indexes. However, there is insufficient evidence to support or to refute effects of ursodeoxycholic acid on disease's course as well as the viral load. better method of clinical trials are needed to obtain a valid and applicable result for daily practice.

Transformation-associated changes in sphingolipid metabolism sensitize cells to lysosomal cell death induced by inhibitors of acid sphingomyelinase

DEFF Research Database (Denmark)

Petersen, Nikolaj H T; Olsen, Ole D; Groth-Pedersen, Line

2013-01-01

Lysosomal membrane permeabilization and subsequent cell death may prove useful in cancer treatment, provided that cancer cell lysosomes can be specifically targeted. Here, we identify acid sphingomyelinase (ASM) inhibition as a selective means to destabilize cancer cell lysosomes. Lysosome......-destabilizing experimental anticancer agent siramesine inhibits ASM by interfering with the binding of ASM to its essential lysosomal cofactor, bis(monoacylglycero)phosphate. Like siramesine, several clinically relevant ASM inhibitors trigger cancer-specific lysosomal cell death, reduce tumor growth in vivo, and revert...

[Cyclooxygenase inhibitors and antiplatelet effect of acetylsalicylic acid. selective approach to nonsteroidal anti-inflammatory drugs in cardiological practice].

Science.gov (United States)

Lomakin, N V; Gruzdev, A K

2011-01-01

Nonsteroidal anti-inflammatory drugs (NSAIDs) represent class of medicines which is wide concerning chemical structure and mechanism of action. In the light of contradictory data on efficacy and safety of NSAID in cardiovascular patients selection of most appropriate NSAID (basing on profile of efficacy and safety) in patients receiving continuous therapy with low dose aspirin appears to be a problem. In this paper we discuss peculiarities of drug interaction between cyclooxygenase inhibitors and acetylsalicylic acid, and principles of selection of adequate NSAI.

Effect of Semen on Vaginal Fluid Cytokines and Secretory Leukocyte Protease Inhibitor

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Kathy J. Agnew

2008-01-01

Methods: 138 pregnant women had vaginal fluid collected for Gram stain, acid phosphatase detection by colorimetric assay, and interleukin 1-Beta, interleukin-6, interleukin-8, and secretory leukocyte protease inhibitor measurement by enzyme immunoassay. Results for women with and without acid phosphatase were compared by Mann-Whitney test. Results: of 138 subjects, 28 (20% had acid phosphatase detected; of these, only 19 (68% reported recent intercourse and 3 (11% had sperm seen on Gram stain. There were no significant differences in proinflammatory cytokine concentrations; however, secretory leukocyte protease inhibitor concentrations were significantly higher among women with acid phosphatase. Conclusions: proinflammatory cytokine measurement does not appear to be affected by the presence of semen, but secretory leukocyte protease inhibitor is significantly higher when semen is present. Detection of semen by acid phosphatase was associated with higher vaginal SLPI concentrations, however, the presence of semen did not appear to influence vaginal proinflammatory cytokine concentrations.

Omega-3 and Omega-6 Fatty Acids Act as Inhibitors of the Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 Activity.

Science.gov (United States)

Nicolai, Eleonora; Sinibaldi, Federica; Sannino, Gianpaolo; Laganà, Giuseppina; Basoli, Francesco; Licoccia, Silvia; Cozza, Paola; Santucci, Roberto; Piro, Maria Cristina

2017-08-01

Polyunsaturated fatty acids have been reported to play a protective role in a wide range of diseases characterized by an increased metalloproteinases (MMPs) activity. The recent finding that omega-3 and omega-6 fatty acids exert an anti-inflammatory effect in periodontal diseases has stimulated the present study, designed to determine whether such properties derive from a direct inhibitory action of these compounds on the activity of MMPs. To this issue, we investigated the effect exerted by omega-3 and omega-6 fatty acids on the activity of MMP-2 and MMP-9, two enzymes that actively participate to the destruction of the organic matrix of dentin following demineralization operated by bacteria acids. Data obtained (both in vitro and on ex-vivo teeth) reveal that omega-3 and omega-6 fatty acids inhibit the proteolytic activity of MMP-2 and MMP-9, two enzymes present in dentin. This observation is of interest since it assigns to these compounds a key role as MMPs inhibitors, and stimulates further study to better define their therapeutic potentialities in carious decay.

Experimental and theoretical studies of benzoxazines corrosion inhibitors

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Abdulhadi Kadhim

Full Text Available 2-Methyl-4H-benzo[d][1,3]oxazin-4-one (BZ1 and 3-amino-2-methylquinazolin-4(3H-one (BZ2 were evaluated for their corrosion inhibition properties on mild steel (MS in hydrochloric acid solution by weight loss technique and scanning electron microscopy. Results show the inhibition efficiency values depend on the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight with maximum inhibition efficiency of 89% and 65% for BZ2 and BZ1 at highest concentration of the compounds. Keywords: Methylquinazoline, Benzoxazines, Corrosion, Inhibitors

Baphia nitida Leaves Extract as a Green Corrosion Inhibitor for the Corrosion of Mild Steel in Acidic Media

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V. O. Njoku

2014-01-01

Full Text Available The inhibiting effect of Baphia nitida (BN leaves extract on the corrosion of mild steel in 1 M H2SO4 and 2 M HCl was studied at different temperatures using gasometric and weight loss techniques. The results showed that the leaves extract is a good inhibitor for mild steel corrosion in both acid media and better performances were obtained in 2 M HCl solutions. Inhibition efficiency was found to increase with increasing inhibitor concentration and decreasing temperature. The addition of halides to the extract enhanced the inhibition efficiency due to synergistic effect which improved adsorption of cationic species present in the extract and was in the order KCl < KBr < KI suggesting possible role of radii of the halide ions. Thermodynamic parameters determined showed that the adsorption of BN on the metal surface is an exothermic and spontaneous process and that the adsorption was via a physisorption mechanism.

A preclinical study on the rescue of normal tissue by nicotinic acid in high-dose treatment with APO866, a specific nicotinamide phosphoribosyltransferase inhibitor

DEFF Research Database (Denmark)

Olesen, Uffe Høgh; Thougaard, Annemette V; Jensen, Peter Buhl

2010-01-01

Inhibitor of nicotinamide phosphoribosyltransferase APO866 is a promising cancer drug currently in phase II clinical trials in oncology. Here, we present a strategy for increasing the therapeutic potential of APO866 through the rescue of normal tissues by coadministration of nicotinic acid (Vitam...

On the use of triazines as inhibitors of steel corrosion

International Nuclear Information System (INIS)

Sizaya, O.I.; Andrushko, A.P.

2004-01-01

A possibility of using substandard pesticides as a raw materials for synthesis of a set of triazines and also using them as a inhibitors of acidic corrosion of steel 20, as well as additions to epoxy powder coatings is considered. It is shown that triazines studied are inhibitors of acidic corrosion of steel 20. 2,4-di(ethylamino)-6-phenylhydrazono-1,3,5-triazine (In 4) has a maximum inhibiting effect among the studied compounds [ru

Occult hepatitis B virus among the patients with abnormal alanine transaminase.

Science.gov (United States)

Makvandi, Manoochehr; Neisi, Niloofar; Khalafkhany, Davod; Makvandi, Kamyar; Hajiani, Eskandar; Shayesteh, Ali Akbar; Masjedi Zadeh, Abdolrahim; Sina, Amir Hosein; Hamidifard, Mojtaba; Rasti, Mojtaba; Aryan, Ehsan; Ahmadi, Kambiz; Yad Yad, Mohammad Jafar

2014-08-01

The occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the sera or in the liver biopsy and the absence of hepatitis B surface antigen (HBsAg) by serological test. The current study aimed to evaluate the occult HBV infection by polymerase chain reaction (PCR) and determine HBV genotyping among the patients with abnormal alanine transaminase (ALT) in Ahvaz city, Iran. The sera of 120 patients, 54 (45%) females and 66 (55%) males, with abnormal ALT 40-152 IU were collected. All the patients were negative for HBsAg for more than one year. The patients` sera were tested by PCR using primers specified for the S region of HBV. Then the positive PCR products were sequenced to determine HBV genotyping and phylogenic tree. Of these 120 subjects, 12 (10%) patients including 6 (5%) males and 6 (5%) females were found positive for HBV DNA by PCR, which indicated the presence of occult HBV infection among these patients. The sequencing results revealed that genotype D was predominant with sub-genotyping D1 among OBI patients. Occult hepatitis B infection is remarkably prevalent in Ahvaz, Iran, and should be considered as a potential risk factor for the transmission of Hepatitis B Virus throughout the community by the carriers.

Development of Matrix Metalloproteinase-2 Inhibitors for Cardioprotection

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Péter Bencsik

2018-04-01

Full Text Available The objective of our present study is to develop novel inhibitors for MMP-2 for acute cardioprotection. In a series of pilot studies, novel substituted carboxylic acid derivatives were synthesized based on imidazole and thiazole scaffolds and then tested in a screeening cascade for MMP inhibition. We found that the MMP-inhibiting effects of imidazole and thiazole carboxylic acid-based compounds are superior in efficacy in comparison to the conventional hydroxamic acid derivatives of the same molecules. Based on these results, a 568-membered focused library of imidazole and thiazole compounds was generated in silico and then the library members were docked to the 3D model of MMP-2 followed by an in vitro medium throughput screening (MTS based on a fluorescent assay employing MMP-2 catalytic domain. Altogether 45 compounds showed a docking score of >70, from which 30 compounds were successfully synthesized. Based on the MMP-2 inhibitory tests using gelatin zymography, 7 compounds were then selected and tested in neonatal rat cardiac myocytes subjected to simulated I/R injury. Six compounds showed significant cardio-cytoprotecion and the most effective compound (MMPI-1154 significantly decreased infarct size when applied at 1 μM in an ex vivo model for acute myocardial infarction. This is the first demonstration that imidazole and thiazole carboxylic acid-based compounds are more efficacious MMP-2 inhibitor than their hydroxamic acid derivatives. MMPI-1154 is a promising novel cardio-cytoprotective imidazole-carboxylic acid MMP-2 inhibitor lead candidate for the treatment of acute myocardial infarction.

Development of Matrix Metalloproteinase-2 Inhibitors for Cardioprotection

Science.gov (United States)

Bencsik, Péter; Kupai, Krisztina; Görbe, Anikó; Kenyeres, Éva; Varga, Zoltán V.; Pálóczi, János; Gáspár, Renáta; Kovács, László; Weber, Lutz; Takács, Ferenc; Hajdú, István; Fabó, Gabriella; Cseh, Sándor; Barna, László; Csont, Tamás; Csonka, Csaba; Dormán, György; Ferdinandy, Péter

2018-01-01

The objective of our present study is to develop novel inhibitors for MMP-2 for acute cardioprotection. In a series of pilot studies, novel substituted carboxylic acid derivatives were synthesized based on imidazole and thiazole scaffolds and then tested in a screeening cascade for MMP inhibition. We found that the MMP-inhibiting effects of imidazole and thiazole carboxylic acid-based compounds are superior in efficacy in comparison to the conventional hydroxamic acid derivatives of the same molecules. Based on these results, a 568-membered focused library of imidazole and thiazole compounds was generated in silico and then the library members were docked to the 3D model of MMP-2 followed by an in vitro medium throughput screening (MTS) based on a fluorescent assay employing MMP-2 catalytic domain. Altogether 45 compounds showed a docking score of >70, from which 30 compounds were successfully synthesized. Based on the MMP-2 inhibitory tests using gelatin zymography, 7 compounds were then selected and tested in neonatal rat cardiac myocytes subjected to simulated I/R injury. Six compounds showed significant cardio-cytoprotecion and the most effective compound (MMPI-1154) significantly decreased infarct size when applied at 1 μM in an ex vivo model for acute myocardial infarction. This is the first demonstration that imidazole and thiazole carboxylic acid-based compounds are more efficacious MMP-2 inhibitor than their hydroxamic acid derivatives. MMPI-1154 is a promising novel cardio-cytoprotective imidazole-carboxylic acid MMP-2 inhibitor lead candidate for the treatment of acute myocardial infarction. PMID:29674965

The Role of Ursodeoxycholic Acid in Acute Viral Hepatitis: an Evidence-based Case Report

Directory of Open Access Journals (Sweden)

Indra Wijaya

2015-12-01

Full Text Available Aim: to review the role of ursodeoxycholic acid in acute viral hepatitis. Methods: following literature searching according to the clinical question on Pubmed and Cochrane Library. After filtered with our inclusion and exclusion criteria, one meta-analysis and two randomized clinical trials are obtained. Through critical appraisal, it was concluded that the articles meet the criteria for validity and relevance. Results: the article found that there is a positive effect of ursodeoxycholic acid on the activity of serum transaminases and cholestasis indexes. However, there is insufficient evidence to support or to refute effects of  ursodeoxycholic acid on disease’s course as well as the viral load. Conclusion: better method of clinical trials are needed to obtain a valid and applicable result for daily practice. Key words: ursodeoxycholic acid, acute viral hepatitis

Kinetics of corrosion inhibition of aluminum in acidic media by water-soluble natural polymeric chondroitin-4-sulfate as anionic polyelectrolyte inhibitor.

Science.gov (United States)

Hassan, Refat M; Ibrahim, Samia M; Takagi, Hideo D; Sayed, Suzan A

2018-07-15

Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyelectrolyte chondroitin-4-sulfate (CS) polysaccharide has been studied using both gasometrical and weight-loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing the inhibitor concentration and decreased with increasing temperature. The inhibition action of CS on Al metal surface was found to obey both of Langmuir and Freundlich isotherms. The factors affecting the corrosion rates such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and the temperature were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the results obtained is discussed. Copyright © 2018. Published by Elsevier Ltd.

Pertussis toxin, an inhibitor of G(αi PCR, inhibits bile acid- and cytokine-induced apoptosis in primary rat hepatocytes.

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Golnar Karimian

Full Text Available Excessive hepatocyte apoptosis is a common event in acute and chronic liver diseases leading to loss of functional liver tissue. Approaches to prevent apoptosis have therefore high potential for the treatment of liver disease. G-protein coupled receptors (GPCR play crucial roles in cell fate (proliferation, cell death and act through heterotrimeric G-proteins. G(αiPCRs have been shown to regulate lipoapoptosis in hepatocytes, but their role in inflammation- or bile acid-induced apoptosis is unknown. Here, we analyzed the effect of inhibiting G(αiPCR function, using pertussis toxin (PT, on bile acid- and cytokine-induced apoptosis in hepatocytes. Primary rat hepatocytes, HepG2-rNtcp cells (human hepatocellular carcinoma cells or H-4-II-E cells (rat hepatoma cells were exposed to glycochenodeoxycholic acid (GCDCA or tumor necrosis factor-α (TNFα/actinomycin D (ActD. PT (50-200 nmol/L was added 30 minutes prior to the apoptotic stimulus. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (sytox green staining were assessed. PT significantly reduced GCDCA- and TNFα/ActD-induced apoptosis in rat hepatocytes (-60%, p<0.05 in a dose-dependent manner (with no shift to necrosis, but not in HepG2-rNtcp cells or rat H-4-II-E cells. The protective effect of pertussis toxin was independent of the activation of selected cell survival signal transduction pathways, including ERK, p38 MAPK, PI3K and PKC pathways, as specific protein kinase inhibitors did not reverse the protective effects of pertussis toxin in GCDCA-exposed hepatocytes.Pertussis toxin, an inhibitor of G(αiPCRs, protects hepatocytes, but not hepatocellular carcinoma cells, against bile acid- and cytokine-induced apoptosis and has therapeutic potential as primary hepatoprotective drug, as well as adjuvant in anti-cancer therapy.

Inhibitors of plant hormone transport

Czech Academy of Sciences Publication Activity Database

Klíma, Petr; Laňková, Martina; Zažímalová, Eva

2016-01-01

Roč. 253, č. 6 (2016), s. 1391-1404 ISSN 0033-183X R&D Projects: GA MŠk(CZ) LD15088 Institutional support: RVO:61389030 Keywords : polar auxin transport * acid-binding protein * gnom arf-gef * equilibrative nucleoside transporter * efflux carrier polarity * plasma-membrane-protein * cultured tobacco cells * arabidopsis-thaliana * gravitropic response * brefeldin-a * Plant hormones * Transport * Inhibitors * Auxin * Cytokinins * Strigolactones * Abscisic acid * Cell biology Subject RIV: ED - Physiology Impact factor: 2.870, year: 2016

Boronic species as promising inhibitors of the Staphylococcus aureus NorA efflux pump: study of 6-substituted pyridine-3-boronic acid derivatives.

Science.gov (United States)

Fontaine, Fanny; Héquet, Arnaud; Voisin-Chiret, Anne-Sophie; Bouillon, Alexandre; Lesnard, Aurélien; Cresteil, Thierry; Jolivalt, Claude; Rault, Sylvain

2015-05-05

In response to the extensive use of antibiotics, bacteria have evolved numerous mechanisms of defense against antimicrobial agents. Among them, extrusion of the antimicrobial agents outside the bacterial cell through efflux pumps is a major cause of concern. At first limited to one or few structurally-related antibiotics, bacterial resistance have then progressed towards cross-resistance between different classes of antibiotics, leading to multidrug-resistant microorganisms. Emergence of these pathogens requires development of novel therapeutic strategies and inhibition of efflux pumps appears to be a promising strategy that could restore the potency of existing antibiotics. NorA is the most studied chromosomal efflux pump of Staphylococcus aureus; it is known to be implied in resistance of Methicillin-resistant S. aureus (MRSA) strains against a wide range of unrelated substrates, including hydrophilic fluoroquinolones. Starting from 6-benzyloxypyridine-3-boronic acid I that we previously identified as a potential inhibitor of the NorA efflux pump against the NorA-overexpressing S. aureus 1199B strain (SA1199B), we describe here the synthesis and biological evaluation of a series of 6-(aryl)alkoxypyridine-3-boronic acids. 6-(3-Phenylpropoxy)pyridine-3-boronic acid 3i and 6-(4-phenylbutoxy)pyridine-3-boronic acid 3j were found to potentiate ciprofloxacin activity by a 4-fold increase compared to the parent compound I. In addition, it has been shown that both compounds promote Ethidium Bromide (EtBr) accumulation in SA1199B, thus corroborating their potential mode of action as NorA inhibitors. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

Energy Technology Data Exchange (ETDEWEB)

Moussa, M.N.H.; El-Far, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt); El-Shafei, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt)], E-mail: ashafei@mans.edu.eg

2007-09-15

Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation.

The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

International Nuclear Information System (INIS)

Moussa, M.N.H.; El-Far, A.A.; El-Shafei, A.A.

2007-01-01

Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation

Inhibition studies of soybean (Glycine max) urease with heavy metals, sodium salts of mineral acids, boric acid, and boronic acids.

Science.gov (United States)

Kumar, Sandeep; Kayastha, Arvind M

2010-10-01

Various inhibitors were tested for their inhibitory effects on soybean urease. The K(i) values for boric acid, 4-bromophenylboronic acid, butylboronic acid, and phenylboronic acid were 0.20 +/- 0.05 mM, 0.22 +/- 0.04 mM, 1.50 +/- 0.10 mM, and 2.00 +/- 0.11 mM, respectively. The inhibition was competitive type with boric acid and boronic acids. Heavy metal ions including Ag(+), Hg(2+), and Cu(2+) showed strong inhibition on soybean urease, with the silver ion being a potent inhibitor (IC(50) = 2.3 x 10(-8) mM). Time-dependent inhibition studies exhibited biphasic kinetics with all heavy metal ions. Furthermore, inhibition studies with sodium salts of mineral acids (NaF, NaCl, NaNO(3), and Na(2)SO(4)) showed that only F(-) inhibited soybean urease significantly (IC(50) = 2.9 mM). Competitive type of inhibition was observed for this anion with a K(i) value of 1.30 mM.

Novel nonpeptidic inhibitors of peptide deformylase.

Science.gov (United States)

Jayasekera, M M; Kendall, A; Shammas, R; Dermyer, M; Tomala, M; Shapiro, M A; Holler, T P

2000-09-15

A novel series of nonpeptidic compounds structurally related to the known anticholesteremic thyropropic acid were found to inhibit Escherichia coli peptide deformylase (PDF), with IC50 values in the low-micromolar range. Kinetic analysis of [4-(4-hydroxyphenoxy)-3,5-diiodophenyl]acetic acid reveals competitive inhibition, with a Ki value of 0.66 +/- 0.007 microM. A structure-activity relationship study demonstrates that the carboxylate is required for activity, while the distal phenolic function can be methylated without significant effect. Either decreasing the number of iodine atoms on the molecule to one or increasing the number of iodine atoms to four results in the loss of an order of magnitude in potency. These compounds are the first nonpeptidic inhibitors disclosed and represent a template from which better inhibitors might be designed.

Chiral Amine Synthesis Using ω-Transaminases: An Amine Donor that Displaces Equilibria and Enables High-Throughput Screening**

Science.gov (United States)

Green, Anthony P; Turner, Nicholas J; O'Reilly, Elaine

2014-01-01

The widespread application of ω-transaminases as biocatalysts for chiral amine synthesis has been hampered by fundamental challenges, including unfavorable equilibrium positions and product inhibition. Herein, an efficient process that allows reactions to proceed in high conversion in the absence of by-product removal using only one equivalent of a diamine donor (ortho-xylylenediamine) is reported. This operationally simple method is compatible with the most widely used (R)- and (S)-selective ω-TAs and is particularly suitable for the conversion of substrates with unfavorable equilibrium positions (e.g., 1-indanone). Significantly, spontaneous polymerization of the isoindole by-product generates colored derivatives, providing a high-throughput screening platform to identify desired ω-TA activity. PMID:25138082

Bacterial fatty acid metabolism in modern antibiotic discovery.

Science.gov (United States)

Yao, Jiangwei; Rock, Charles O

2017-11-01

Bacterial fatty acid synthesis is essential for many pathogens and different from the mammalian counterpart. These features make bacterial fatty acid synthesis a desirable target for antibiotic discovery. The structural divergence of the conserved enzymes and the presence of different isozymes catalyzing the same reactions in the pathway make bacterial fatty acid synthesis a narrow spectrum target rather than the traditional broad spectrum target. Furthermore, bacterial fatty acid synthesis inhibitors are single-targeting, rather than multi-targeting like traditional monotherapeutic, broad-spectrum antibiotics. The single-targeting nature of bacterial fatty acid synthesis inhibitors makes overcoming fast-developing, target-based resistance a necessary consideration for antibiotic development. Target-based resistance can be overcome through multi-targeting inhibitors, a cocktail of single-targeting inhibitors, or by making the single targeting inhibitor sufficiently high affinity through a pathogen selective approach such that target-based mutants are still susceptible to therapeutic concentrations of drug. Many of the pathogens requiring new antibiotic treatment options encode for essential bacterial fatty acid synthesis enzymes. This review will evaluate the most promising targets in bacterial fatty acid metabolism for antibiotic therapeutics development and review the potential and challenges in advancing each of these targets to the clinic and circumventing target-based resistance. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

Xanthine oxidoreductase and its inhibitors: relevance for gout.

Science.gov (United States)

Day, Richard O; Kamel, Bishoy; Kannangara, Diluk R W; Williams, Kenneth M; Graham, Garry G

2016-12-01

Xanthine oxidoreductase (XOR) is the rate-limiting enzyme in purine catabolism and converts hypoxanthine to xanthine, and xanthine into uric acid. When concentrations of uric acid exceed its biochemical saturation point, crystals of uric acid, in the form of monosodium urate, emerge and can predispose an individual to gout, the commonest form of inflammatory arthritis in men aged over 40 years. XOR inhibitors are primarily used in the treatment of gout, reducing the formation of uric acid and thereby, preventing the formation of monosodium urate crystals. Allopurinol is established as first-line therapy for gout; a newer alternative, febuxostat, is used in patients unable to tolerate allopurinol. This review provides an overview of gout, a detailed analysis of the structure and function of XOR, discussion on the pharmacokinetics and pharmacodynamics of XOR inhibitors-allopurinol and febuxostat, and the relevance of XOR in common comorbidities of gout. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Wheat Subtilisin/Chymotrypsin Inhibitor (WSCI) as a scaffold for novel serine protease inhibitors with a given specificity.

Science.gov (United States)

Tedeschi, Francesca; Di Maro, Antimo; Facchiano, Angelo; Costantini, Susan; Chambery, Angela; Bruni, Natalia; Capuzzi, Valeria; Ficca, Anna Grazia; Poerio, Elia

2012-10-30

WSCI (Wheat Subtilisin/Chymotrypsin Inhibitor) is a small protein belonging to the Potato inhibitor I family exhibiting a high content of essential amino acid. In addition to bacterial subtilisins and mammalian chymotrypsins, WSCI inhibits chymotrypsin-like activities isolated from digestive traits of a number of insect larvae. In vivo, as suggested for many plant proteinase inhibitors, WSCI seems to play a role of natural defence against attacks of pests and pathogens. The functional region of WSCI, containing the inhibitor reactive site (Met48-Glu49), corresponds to an extended flexible loop (Val42-Asp53) whose architecture is somehow stabilized by a number of secondary interactions established with a small β-sheet located underneath. The aim of this study was to employ a WSCI molecule as a stable scaffold to obtain recombinant inhibitors with new acquired anti-proteinase activity or, alternatively, inactive WSCI variants. A gene sequence coding for the native WSCI, along with genes coding for muteins with different specficities, could be exploited to obtain transformed non-food use plants with improved insect resistance. On the other hand, the genetic transformation of cereal plants over-expressing inactive WSCI muteins could represent a possible strategy to improve the nutritional quality of cereal-based foods, without risk of interference with human or animal digestive enzymes. Here, we described the characterization of four muteins containing single/multiple amino acid substitutions at the WSCI reactive site and/or at its proximity. Modalities of interaction of these muteins with proteinases (subtilisin, trypsin and chymotrypsin) were investigated by time course hydrolysis and molecular simulations studies.

Inhibitors of the 5-lipoxygenase arachidonic acid pathway induce ATP release and ATP-dependent organic cation transport in macrophages.

Science.gov (United States)

da Silva-Souza, Hercules Antônio; Lira, Maria Nathalia de; Costa-Junior, Helio Miranda; da Cruz, Cristiane Monteiro; Vasconcellos, Jorge Silvio Silva; Mendes, Anderson Nogueira; Pimenta-Reis, Gabriela; Alvarez, Cora Lilia; Faccioli, Lucia Helena; Serezani, Carlos Henrique; Schachter, Julieta; Persechini, Pedro Muanis

2014-07-01

We have previously described that arachidonic acid (AA)-5-lipoxygenase (5-LO) metabolism inhibitors such as NDGA and MK886, inhibit cell death by apoptosis, but not by necrosis, induced by extracellular ATP (ATPe) binding to P2X7 receptors in macrophages. ATPe binding to P2X7 also induces large cationic and anionic organic molecules uptake in these cells, a process that involves at least two distinct transport mechanisms: one for cations and another for anions. Here we show that inhibitors of the AA-5-LO pathway do not inhibit P2X7 receptors, as judged by the maintenance of the ATPe-induced uptake of fluorescent anionic dyes. In addition, we describe two new transport phenomena induced by these inhibitors in macrophages: a cation-selective uptake of fluorescent dyes and the release of ATP. The cation uptake requires secreted ATPe, but, differently from the P2X7/ATPe-induced phenomena, it is also present in macrophages derived from mice deficient in the P2X7 gene. Inhibitors of phospholipase A2 and of the AA-cyclooxygenase pathway did not induce the cation uptake. The uptake of non-organic cations was investigated by measuring the free intracellular Ca(2+) concentration ([Ca(2+)]i) by Fura-2 fluorescence. NDGA, but not MK886, induced an increase in [Ca(2+)]i. Chelating Ca(2+) ions in the extracellular medium suppressed the intracellular Ca(2+) signal without interfering in the uptake of cationic dyes. We conclude that inhibitors of the AA-5-LO pathway do not block P2X7 receptors, trigger the release of ATP, and induce an ATP-dependent uptake of organic cations by a Ca(2+)- and P2X7-independent transport mechanism in macrophages. Copyright © 2014 Elsevier B.V. All rights reserved.

A structural insight into the P1S1 binding mode of diaminoethylphosphonic and phosphinic acids, selective inhibitors of alanine aminopeptidases

Energy Technology Data Exchange (ETDEWEB)

Węglarz-Tomczak, Ewelina; Berlicki, Łukasz; Pawełczak, Małgorzata; Nocek, Bogusław; Joachimiak, Andrzej; Mucha, Artur

2016-07-01

N0 -substituted 1,2-diaminoethylphosphonic acids and 1,2-diaminoethylphosphinic dipeptides were explored to unveil the structural context of the unexpected selectivity of these inhibitors of M1 alanine aminopeptidases (APNs) versus M17 leucine aminopeptidase (LAP). The diaminophosphonic acids were obtained via aziridines in an improved synthetic procedure that was further expanded for the phosphinic pseudodipeptide system. The inhibitory activity, measured for three M1 and one M17 metalloaminopeptidases of different sources (bacterial, human and porcine), revealed several potent compounds (e.g., Ki ¼ 65 nM of 1u for HsAPN). Two structures of an M1 representative (APN from Neisseria meningitidis) in complex with N-benzyl-1,2-diaminoethylphosphonic acid and N-cyclohexyl-1,2- diaminoethylphosphonic acid were determined by the X-ray crystallography. The analysis of these structures and the models of the phosphonic acid complexes of the human ortholog provided an insight into the role of the additional amino group and the hydrophobic substituents of the ligands within the S1 active site region.

Monoamine depletion by reuptake inhibitors

Directory of Open Access Journals (Sweden)

Hinz M

2011-10-01

Full Text Available Marty Hinz1, Alvin Stein2, Thomas Uncini31Clinical Research, NeuroResearch Clinics Inc, Cape Coral, FL; 2Stein Orthopedic Associates, Plantation, FL; 3DBS Labs Inc, Duluth, MN, USABackground: Disagreement exists regarding the etiology of cessation of the observed clinical results with administration of reuptake inhibitors. Traditionally, when drug effects wane, it is known as tachyphylaxis. With reuptake inhibitors, the placebo effect is significantly greater than the drug effect in the treatment of depression and attention deficit hyperactivity disorder, leading some to assert that waning of drug effects is placebo relapse, not tachyphylaxis.Methods: Two groups were retrospectively evaluated. Group 1 was composed of subjects with depression and Group 2 was composed of bariatric subjects treated with reuptake inhibitors for appetite suppression.Results: In Group 1, 200 subjects with depression were treated with citalopram 20 mg per day. A total of 46.5% (n = 93 achieved relief of symptoms (Hamilton-D rating score ≤ 7, of whom 37 (39.8% of whom experienced recurrence of depression symptoms, at which point an amino acid precursor formula was started. Within 1–5 days, 97.3% (n = 36 experienced relief of depression symptoms. In Group 2, 220 subjects were treated with phentermine 30 mg in the morning and citalopram 20 mg at 4 pm. In this group, 90.0% (n = 198 achieved adequate appetite suppression. The appetite suppression ceased in all 198 subjects within 4–48 days. Administration of an amino acid precursor formula restored appetite suppression in 98.5% (n = 195 of subjects within 1–5 days.Conclusion: Reuptake inhibitors do not increase the total number of monoamine molecules in the central nervous system. Their mechanism of action facilitates redistribution of monoamines from one place to another. In the process, conditions are induced that facilitate depletion of monoamines. The "reuptake inhibitor monoamine depletion theory" of this paper

A novel method for screening the glutathione transferase inhibitors

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Węgrzyn Grzegorz

2009-03-01

Full Text Available Abstract Background Glutathione transferases (GSTs belong to the family of Phase II detoxification enzymes. GSTs catalyze the conjugation of glutathione to different endogenous and exogenous electrophilic compounds. Over-expression of GSTs was demonstrated in a number of different human cancer cells. It has been found that the resistance to many anticancer chemotherapeutics is directly correlated with the over-expression of GSTs. Therefore, it appears to be important to find new GST inhibitors to prevent the resistance of cells to anticancer drugs. In order to search for glutathione transferase (GST inhibitors, a novel method was designed. Results Our results showed that two fragments of GST, named F1 peptide (GYWKIKGLV and F2 peptide (KWRNKKFELGLEFPNL, can significantly inhibit the GST activity. When these two fragments were compared with several known potent GST inhibitors, the order of inhibition efficiency (measured in reactions with 2,4-dinitrochlorobenzene (CDNB and glutathione as substrates was determined as follows: tannic acid > cibacron blue > F2 peptide > hematin > F1 peptide > ethacrynic acid. Moreover, the F1 peptide appeared to be a noncompetitive inhibitor of the GST-catalyzed reaction, while the F2 peptide was determined as a competitive inhibitor of this reaction. Conclusion It appears that the F2 peptide can be used as a new potent specific GST inhibitor. It is proposed that the novel method, described in this report, might be useful for screening the inhibitors of not only GST but also other enzymes.

Novel peptide-based protease inhibitors

DEFF Research Database (Denmark)

Roodbeen, Renée

of novel peptide-based protease inhibitors, efforts were made towards improved methods for peptide synthesis. The coupling of Fmoc-amino acids onto N-methylated peptidyl resins was investigated. These couplings can be low yielding and the effect of the use of microwave heating combined with the coupling...

4-Hydroxyphenylpyruvate Dioxygenase Inhibitors: From Chemical Biology to Agrochemicals.

Science.gov (United States)

Ndikuryayo, Ferdinand; Moosavi, Behrooz; Yang, Wen-Chao; Yang, Guang-Fu

2017-10-04

The development of new herbicides is receiving considerable attention to control weed biotypes resistant to current herbicides. Consequently, new enzymes are always desired as targets for herbicide discovery. 4-Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) is an enzyme engaged in photosynthetic activity and catalyzes the transformation of 4-hydroxyphenylpyruvic acid (HPPA) into homogentisic acid (HGA). HPPD inhibitors constitute a promising area of discovery and development of innovative herbicides with some advantages, including excellent crop selectivity, low application rates, and broad-spectrum weed control. HPPD inhibitors have been investigated for agrochemical interests, and some of them have already been commercialized as herbicides. In this review, we mainly focus on the chemical biology of HPPD, discovery of new potential inhibitors, and strategies for engineering transgenic crops resistant to current HPPD-inhibiting herbicides. The conclusion raises some relevant gaps for future research directions.

Occult Hepatitis B Virus Among the Patients With Abnormal Alanine Transaminase

Science.gov (United States)

Makvandi, Manoochehr; Neisi, Niloofar; Khalafkhany, Davod; Makvandi, Kamyar; Hajiani, Eskandar; Shayesteh, Ali Akbar; Masjedi Zadeh, Abdolrahim; Sina, Amir Hosein; Hamidifard, Mojtaba; Rasti, Mojtaba; Aryan, Ehsan; Ahmadi, Kambiz; Yad Yad, Mohammad Jafar

2014-01-01

Background: The occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the sera or in the liver biopsy and the absence of hepatitis B surface antigen (HBsAg) by serological test. Objectives: The current study aimed to evaluate the occult HBV infection by polymerase chain reaction (PCR) and determine HBV genotyping among the patients with abnormal alanine transaminase (ALT) in Ahvaz city, Iran. Patients and Methods: The sera of 120 patients, 54 (45%) females and 66 (55%) males, with abnormal ALT 40-152 IU were collected. All the patients were negative for HBsAg for more than one year. The patients` sera were tested by PCR using primers specified for the S region of HBV. Then the positive PCR products were sequenced to determine HBV genotyping and phylogenic tree. Results: Of these 120 subjects, 12 (10%) patients including 6 (5%) males and 6 (5%) females were found positive for HBV DNA by PCR, which indicated the presence of occult HBV infection among these patients. The sequencing results revealed that genotype D was predominant with sub-genotyping D1 among OBI patients. Conclusions: Occult hepatitis B infection is remarkably prevalent in Ahvaz, Iran, and should be considered as a potential risk factor for the transmission of Hepatitis B Virus throughout the community by the carriers. PMID:25485052

The nucleic acids as early indicators of the recovery of patients subjected to total body irradiation for bone marrow transplant

International Nuclear Information System (INIS)

Morera Carrillo, L.M.; Garcia Lima, O.; Carnot, J.; Cardenas, J.

2000-01-01

The possibility to use the concentration of nucleic acids as an early indicator for the recovery of individuals exposed to high radiation was valued in 30 patients subjected to a dose of 10 Gy (cobalt 60) in two or three sessions of total body irradiation for bone marrow transplants. The determination of the concentration of the nucleic acids was carried out prior to the irradiation, and later in different periods until the patients discharge. The behaviour of indicate such as alpha amylase serics transaminases, glicemics, alkaline phosphatase and others was also studied

L-Chicoric acid inhibits human immunodeficiency virus type 1 integration in vivo and is a noncompetitive but reversible inhibitor of HIV-1 integrase in vitro

International Nuclear Information System (INIS)

Reinke, Ryan A.; Lee, Deborah J.; McDougall, Brenda R.; King, Peter J.; Victoria, Joseph; Mao Yingqun; Lei Xiangyang; Reinecke, Manfred G.; Robinson, W. Edward

2004-01-01

The human immunodeficiency virus (HIV) integrase (IN) must covalently join the viral cDNA into a host chromosome for productive HIV infection. L-Chicoric acid (L-CA) enters cells poorly but is a potent inhibitor of IN in vitro. Using quantitative real-time polymerase chain reaction (PCR), L-CA inhibits integration at concentrations from 500 nM to 10 μM but also inhibits entry at concentrations above 1 μM. Using recombinant HIV IN, steady-state kinetic analyses with L-CA were consistent with a noncompetitive or irreversible mechanism of inhibition. IN, in the presence or absence of L-CA, was successively washed. Inhibition of IN diminished, demonstrating that L-CA was reversibly bound to the protein. These data demonstrate that L-CA is a noncompetitive but reversible inhibitor of IN in vitro and of HIV integration in vivo. Thus, L-CA likely interacts with amino acids other than those which bind substrate

Histone deacetylase inhibitors augment doxorubicin-induced DNA damage in cardiomyocytes.

Science.gov (United States)

Ververis, Katherine; Rodd, Annabelle L; Tang, Michelle M; El-Osta, Assam; Karagiannis, Tom C

2011-12-01

Histone deacetylase inhibitors have emerged as a new class of anticancer therapeutics with suberoylanilide hydroxamic acid (Vorinostat) and depsipeptide (Romidepsin) already being approved for clinical use. Numerous studies have identified that histone deacetylase inhibitors will be most effective in the clinic when used in combination with conventional cancer therapies such as ionizing radiation and chemotherapeutic agents. One promising combination, particularly for hematologic malignancies, involves the use of histone deacetylase inhibitors with the anthracycline, doxorubicin. However, we previously identified that trichostatin A can potentiate doxorubicin-induced hypertrophy, the dose-limiting side-effect of the anthracycline, in cardiac myocytes. Here we have the extended the earlier studies and evaluated the effects of combinations of the histone deacetylase inhibitors, trichostatin A, valproic acid and sodium butyrate on doxorubicin-induced DNA double-strand breaks in cardiomyocytes. Using γH2AX as a molecular marker for the DNA lesions, we identified that all of the broad-spectrum histone deacetylase inhibitors tested augment doxorubicin-induced DNA damage. Furthermore, it is evident from the fluorescence photomicrographs of stained nuclei that the histone deacetylase inhibitors also augment doxorubicin-induced hypertrophy. These observations highlight the importance of investigating potential side-effects, in relevant model systems, which may be associated with emerging combination therapies for cancer.

Anti-inflammatory and ameliorative effects of gallic acid on fluoxetine-induced oxidative stress and liver damage in rats.

Science.gov (United States)

Karimi-Khouzani, Omid; Heidarian, Esfandiar; Amini, Sayed Asadollah

2017-08-01

Fluoxetine-induced liver damage is a cause of chronic liver disease. In the present study the hepatoprotective effects of gallic acid against fluoxetine-induced liver damage were examined. Forty-eight male rats were divided into six groups as follow: group 1, the control group; group 2, rats receiving fluoxetine (24mg/kg bw daily, po) without treatment; group 3, rats receiving 24mg/kg bw fluoxetine, treated with 50mg/kg bw silymarin and groups 4, 5, and 6 in which gallic acid (50, 100, and 200mg/kg bw, po, respectively) was prescribed after the consumption of fluoxetine. The histopathological changes of hepatic tissues were checked out. Fluoxetine caused a significant increase in the levels of serum glutamate oxaloacetate transaminase (GOT), serum glutamate pyruvate transaminase (GPT), lipid profiles, urea, fasting blood sugar (FBS), creatinine (Cr), protein carbonyl (PC) content, malondialdehyde (MDA), and liver TNF-α as an inflammatory element. Also, the obtained results of group 2 revealed a significant decline in ferric reducing ability of plasma (FRAP), liver catalase (CAT), superoxide dismutase (SOD), and vitamin C levels. The treatment with gallic acid showed significant ameliorations in abnormalities of fluoxetine-induced liver injury as represented by the improvement of hepatic CAT, SOD activities, vitamin C levels, serum biochemical parameters, and histopathological changes, in addition to the recovery of antioxidant defense system status. Gallic acid has inhibitory effects on fluoxetine-induced liver damage. The effect of gallic acid is derived from free radical scavenging properties and the anti-inflammatory effect related to TNF-α. Copyright © 2017. Published by Elsevier Urban & Partner Sp. z o.o.

Inhibition of neuraminidase by Ganoderma triterpenoids and implications for neuraminidase inhibitor design

Science.gov (United States)

Zhu, Qinchang; Bang, Tran Hai; Ohnuki, Koichiro; Sawai, Takashi; Sawai, Ken; Shimizu, Kuniyoshi

2015-01-01

Neuraminidase (NA) inhibitors are the dominant antiviral drugs for treating influenza in the clinic. Increasing prevalence of drug resistance makes the discovery of new NA inhibitors a high priority. Thirty-one triterpenoids from the medicinal mushroom Ganoderma lingzhi were analyzed in an in vitro NA inhibition assay, leading to the discovery of ganoderic acid T-Q and TR as two inhibitors of H5N1 and H1N1 NAs. Structure-activity relationship studies revealed that the corresponding triterpenoid structure is a potential scaffold for the design of NA inhibitors. Using these triterpenoids as probes we found, through further in silico docking and interaction analysis, that interactions with the amino-acid residues Arg292 and/or Glu119 of NA are critical for the inhibition of H5N1 and H1N1. These findings should prove valuable for the design and development of NA inhibitors. PMID:26307417

Comparative Amino Acid Decomposition Analysis of Potent Type I P38α Inhibitors

Directory of Open Access Journals (Sweden)

Ahmad Ebadi

2013-05-01

Full Text Available Background and purpose of the study:p38α is a member of mitogen-activated protein kinases (MAPK considered as a prominent target in development of anti-inflammatory agents. Any abnormality in the phosphorylation process leads to the different human diseases such as cancer, diabetes and inflammatory diseases. Several small molecule p38α inhibitors have been developed up to now. In this regard, structural elucidation of p38 inhibitors needs to be done enabling us in rational lead development strategies.Methods:Various interactions of three potent inhibitors with p38α active site have been evaluated in terms of binding energies and bond lengths via density function theory and MD simulations.Results:Our comparative study showed that both ab initio and MD simulation led to the relatively similar results in pharmacophore discrimination of p38α inhibitors.Conclusion:The results of the present study may find their usefulness in pharmacophore based modification of p38α inhibitors.

Characterization of inhibitor(s) of β-glucuronidase enzyme activity in GUS-transgenic wheat

KAUST Repository

Ramadan, Ahmed M Ali

2011-06-26

The uidA gene, encoding for β-glucuronidase (GUS), is the most frequently used reporter gene in plants. As a reporter enzyme, GUS can be assayed both qualitatively and quantitatively. In wheat, there are numerous reports of failure in detecting GUS enzyme activity in tissues of transgenic plants, while other reports have suggested presence of β-glucuronidase inhibitor(s) in wheat tissues. In the present study, we show that the β-glucuronidase enzyme activity is not only tissue-specific but also genotype-dependent. Our data demonstrate that the glucuronic acid could be the candidate inhibitor for β-glucuronidase enzyme activity in wheat leaves and roots. It should be noted that the assays to detect β-glucuronidase enzyme activity in wheat should be interpreted carefully. Based on the data of our present study, we recommend studying the chemical pathways, the unintended effects and the possible loss-of-function of any candidate transgene prior to transformation experiments. © 2011 Springer Science+Business Media B.V.

Characterization of inhibitor(s) of β-glucuronidase enzyme activity in GUS-transgenic wheat

KAUST Repository

Ramadan, Ahmed M Ali; Eissa, Hala F.; El-Domyati, Fotouh M.; Saleh, Osama Mesilhy; Ibrahim, Nasser E.; Salama, M. I.; Mahfouz, Magdy M.; Bahieldin, Ahmed M.

2011-01-01

The uidA gene, encoding for β-glucuronidase (GUS), is the most frequently used reporter gene in plants. As a reporter enzyme, GUS can be assayed both qualitatively and quantitatively. In wheat, there are numerous reports of failure in detecting GUS enzyme activity in tissues of transgenic plants, while other reports have suggested presence of β-glucuronidase inhibitor(s) in wheat tissues. In the present study, we show that the β-glucuronidase enzyme activity is not only tissue-specific but also genotype-dependent. Our data demonstrate that the glucuronic acid could be the candidate inhibitor for β-glucuronidase enzyme activity in wheat leaves and roots. It should be noted that the assays to detect β-glucuronidase enzyme activity in wheat should be interpreted carefully. Based on the data of our present study, we recommend studying the chemical pathways, the unintended effects and the possible loss-of-function of any candidate transgene prior to transformation experiments. © 2011 Springer Science+Business Media B.V.

Reversal of alcohol induced testicular hyperlipidemia by supplementation of ascorbic acid and its comparison with abstention in male guinea pigs.

Science.gov (United States)

Radhakrishnakartha, Harikrishnan; Appu, Abhilash Puthuvelvippel; Madambath, Indira

2014-02-01

Chronic ethanol exposure causes hyperlipidemia. The present study was designed to investigate the impact of ascorbic acid supplementation on ethanol induced hyperlipidemia in testis and to compare it with that of abstinence from taking alcohol. Thirty-six male guinea pigs were divided into two groups and were maintained for 90 days as follows (1) control (C) (2) ethanol treated group (E) (4 g/kg body wt/day). Ethanol was administered for 90 days and on 90th day, alanine amino transaminase (ALT), aspartate amino transaminase (AST) and γ-glutamyltransferase (GGT) in serum was assayed. The animals in the ethanol group were further divided into an ascorbic acid supplemented group (25 mg/100 g body wt/day) (E+AA) and an ethanol abstention group (EAG) and those in the control group were divided into a control group and a control+ascorbic acid group (C+AA). There was significant increase in levels of testicular cholesterol, free fatty acid, phospholipids and triglycerides in the ethanol group. There was also a significant increase in the activity of HMG CoA reductase and decrease in activity of testicular glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme in ethanol-ingested animals that further led to decreased levels of serum testosterone. Alcohol administration also enhanced the activity of testicular alcohol dehydrogenase (ADH). Ascorbic acid supplementation and abstention altered all these parameters induced by chronic alcohol administration. Histological studies were also in line with the above results. Ascorbic acid was able to reinstate the cholesterol homeostasis in testis which could have further restored the testicular steroidogenesis. The present study demonstrated that ascorbic acid is effective in reducing the hyperlipidemia induced by chronic alcohol administration and produced a better recovery than abstention.

Phosphatidic acid accumulation and catecholamine release in adrenal chromaffin cells: stimulation by high potassium and by nicotine, and effect of a diacylglycerol kinase inhibitor R 59 022.

Science.gov (United States)

Owen, P J; Jones, J A; Boarder, M R

1991-09-01

Using primary cultures of bovine adrenal chromaffin cells labelled with 32Pi, we show that stimulation with bradykinin, nicotine, or a depolarising concentration of potassium stimulates the accumulation of [32P]phosphatidic acid. The effects of nicotine and potassium are smaller than the effect of bradykinin, and are dependent entirely on extracellular calcium. The diacylglycerol kinase inhibitor R 59 022 attenuates the formation of phosphatidic acid by nicotine and depolarising concentrations of potassium. This inhibitor also blocks the nicotine and potassium stimulation of noradrenaline release from chromaffin cells. Using 45Ca2+ influx studies, we show that the nicotine-evoked calcium influx is also attenuated by R 59 022. These observations contrast with those in another report in which we showed that bradykinin stimulation of either [32P]phosphatidic acid accumulation or noradrenaline release is not affected by R 59 022. It is likely that the calcium influx produced by nicotine and depolarising potassium is blocked by R 59 022 by a mechanism that is independent of its ability to block diacylglycerol kinase. The nicotine- and potassium-stimulated [32P]phosphatidic acid accumulation is a consequence of this calcium influx and presumably reflects calcium activation of either phospholipase C or phospholipase D.

Cui et al., Afr J Tradit Complement Altern Med. (2016) 13(5):114-122 ...

African Journals Online (AJOL)

oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) in serum, .... [2, 2′-azino-bis (3-ethylbenzothiazoline)-6-sulphonic acid] diamonium salt ..... Chaenomeles sinensis fruit extract in streptozotocin-induced diabetic rats.

Purification, partial characterization, and immunological relationships of multiple low molecular weight protease inhibitors of soybean

Energy Technology Data Exchange (ETDEWEB)

Hwang, D L.R.; Lin, K T.D.; Yang, W K; Foard, D E

1977-01-01

Five protease inhibitors, I-V, in the molecular weight range 7000-8000 were purified from Tracy soybeans by ammonium sulfate precipitation, gel filtration on Sephadex G-100 and G-75, and column chromatography on DEAE-cellulose. In common with previously described trypsin inhibitors from legumes, I-V have a high content of half-cystine and lack tryptophan. By contrast with other legume inhibitors, inhibitor II contains 3 methionine residues. Isoelectric points range from 6.2 to 4.2 in order from inhibitor I to V. Molar ratios (inhibitor/enzyme) for 50% trypsin inhibition are I = 4.76, II = 1.32, III = 3.22, IV = 2.17, V = 0.97. Only V inhibits chymotrypsin significantly (molar ratio = 1.33 for 50% inhibition). The sequence of the first 16 N-terminal amino acid residues of inhibitor V is identical to that of the Bowman-Birk inhibitor; all other observations also indicate that inhibitor V and Bowman-Birk are identical. The first 20 N-terminal amino acid residues of inhibitor II show high homology to those of Bowman-Birk inhibitor, differing by 1 deletion and 5 substitutions. Immunological tests show that inhibitors I through IV are fully cross-reactive with each other but are distinct from inhibitor V.

Identification of tyrosinase specific inhibitors from Xanthium strumarium fruit extract using ultrafiltration-high performance liquid chromatography.

Science.gov (United States)

Wang, Zhiqiang; Hwang, Seung Hwan; Huang, Bo; Lim, Soon Sung

2015-10-01

In this study, a strategy based on ultrafiltration-high performance liquid chromatography coupled with diode array detection (UF-HPLC-DAD) was proposed for screening tyrosinase specific inhibitors in Xanthii fructus. The false negatives were distinguished by optimizing the UF-HPLC-DAD parameters to reduce the background noise; the false positives were distinguished by introducing a blocked tyrosinase in the control group for comparison. To obtain the best blocker, the competitive experiments were performed using various known ligands. Using this strategy, three competitive inhibitors (protocatechuic acid; 3,5-di-O-caffeoylquinic acid; and 1,5-di-O-caffeoylquinic acid) and one mixed-type inhibitor (chlorogenic acid) were identified. These results were verified using tyrosinase inhibition assay, kinetic analysis, and structural simulation of the complex. Our experimental results suggest that the proposed strategy could be useful for high-throughput identification of tyrosinase specific inhibitors in natural products. Copyright © 2015 Elsevier B.V. All rights reserved.

Structure of ‘linkerless’ hydroxamic acid inhibitor-HDAC8 complex confirms the formation of an isoform-specific subpocket

Energy Technology Data Exchange (ETDEWEB)

Tabackman, Alexa A.; Frankson, Rochelle; Marsan, Eric S.; Perry, Kay; Cole, Kathryn E. (Ithaca); (Cornell); (Christopher Newport U)

2016-11-04

Histone deacetylases (HDACs) catalyze the hydrolysis of acetylated lysine side chains in histone and non-histone proteins, and play a critical role in the regulation of many biological processes, including cell differentiation, proliferation, senescence, and apoptosis. Aberrant HDAC activity is associated with cancer, making these enzymes important targets for drug design. In general, HDAC inhibitors (HDACi) block the proliferation of tumor cells by inducing cell differentiation, cell cycle arrest, and/or apoptosis, and comprise some of the leading therapies in cancer treatments. To date, four HDACi have been FDA approved for the treatment of cancers: suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza®), romidepsin (FK228, Istodax®), belinostat (Beleodaq®), and panobinostat (Farydak®). Most current inhibitors are pan-HDACi, and non-selectively target a number of HDAC isoforms. Six previously reported HDACi were rationally designed, however, to target a unique sub-pocket found only in HDAC8. While these inhibitors were indeed potent against HDAC8, and even demonstrated specificity for HDAC8 over HDACs 1 and 6, there were no structural data to confirm the mode of binding. Here we report the X-ray crystal structure of Compound 6 complexed with HDAC8 to 1.98 Å resolution. We also describe the use of molecular docking studies to explore the binding interactions of the other 5 related HDACi. Our studies confirm that the HDACi induce the formation of and bind in the HDAC8-specific subpocket, offering insights into isoform-specific inhibition.

Identification and characterization of carprofen as a multitarget fatty acid amide hydrolase/cyclooxygenase inhibitor.

Science.gov (United States)

Favia, Angelo D; Habrant, Damien; Scarpelli, Rita; Migliore, Marco; Albani, Clara; Bertozzi, Sine Mandrup; Dionisi, Mauro; Tarozzo, Glauco; Piomelli, Daniele; Cavalli, Andrea; De Vivo, Marco

2012-10-25

Pain and inflammation are major therapeutic areas for drug discovery. Current drugs for these pathologies have limited efficacy, however, and often cause a number of unwanted side effects. In the present study, we identify the nonsteroidal anti-inflammatory drug carprofen as a multitarget-directed ligand that simultaneously inhibits cyclooxygenase-1 (COX-1), COX-2, and fatty acid amide hydrolase (FAAH). Additionally, we synthesized and tested several derivatives of carprofen, sharing this multitarget activity. This may result in improved analgesic efficacy and reduced side effects (Naidu et al. J. Pharmacol. Exp. Ther.2009, 329, 48-56; Fowler, C. J.; et al. J. Enzyme Inhib. Med. Chem.2012, in press; Sasso et al. Pharmacol. Res.2012, 65, 553). The new compounds are among the most potent multitarget FAAH/COX inhibitors reported so far in the literature and thus may represent promising starting points for the discovery of new analgesic and anti-inflammatory drugs.

Screening of inhibitors for remediation of asphaltene deposits: Experimental and modeling study

Directory of Open Access Journals (Sweden)

Mehdi Madhi

2018-06-01

Full Text Available One of the most severe problems during production from heavy crude oil reservoirs is the formation of asphaltene precipitation and as a result deposition in the tubing, surface facilities and near wellbore region which causes oil production and permeability reduction in addition to rock wettability alteration in the reservoir. So one of the economical ways to prevent such incidents is using the chemicals which are called asphaltene inhibitor.In this study, the influence of three commercial inhibitors, namely; Cetyl Terimethyl Ammonium Bromide (CTAB, Sodium Dodecyl Sulfate (SDS, Triton X-100 and four non-commercial (Benzene, Benzoic Acid, Salicylic Acid, Naphthalene inhibitors on two Iranian crude oils were investigated. This study extends previous works and contributes toward the better understanding of interactions between asphaltene and inhibitor. Effect of functional groups and structure of inhibitors on asphaltene precipitation were studied and it seems clear that the nature and polarity of asphaltene (structure and amount of impurities presented has a significant impact on the selection of inhibitors. asphaltene dispersant tests and Core flood tests were designed for evaluation of inhibitors in static and dynamic conditions. The results revealed distinguished mechanisms for asphaltene solubilization/dispersion (such as hydrogen bonding, π–π interaction and acid-base interaction and influence of additional side group (OH on inhibition power of inhibitor.During the experiments, it was found that increasing inhibitor concentration may lead to the self-assembly of inhibitor and declining of asphaltene stabilization. So, finding optimum concentration of inhibitor with high efficiency and available at a reasonable price is very important. The results suggest that 600 ppm of CTAB and 300 ppm of SDS were approximately optimum concentrations for the studied crude oils. One of the most important findings that differ from previous studies is the

The Effects of Switching to Vonoprazan, a Novel Potassium-Competitive Acid Blocker, on Gastric Acidity and Reflux Patterns in Patients with Erosive Esophagitis Refractory to Proton Pump Inhibitors.

Science.gov (United States)

Yamashita, Hiroshi; Kanamori, Atsushi; Kano, Chise; Hashimura, Hiroki; Matsumoto, Kei; Tsujimae, Masahiro; Yoshizaki, Tetsuya; Momose, Kenji; Obata, Daisuke; Eguchi, Takaaki; Fujita, Mikio; Okada, Akihiko

2017-01-01

The effects of vonoprazan and proton pump inhibitors (PPIs) in patients with reflux esophagitis (RE) have not yet been compared using multichannel intraluminal impedance-pH (MII-pH). A total of 8 patients with persistent gastric mucosal injury, despite completing an 8-week standard PPI therapy, were enrolled in the study. While they were on standard PPI therapy, the baseline values of reflux parameters, holding time ratio (HTR) of gastric pH >4, and esophageal pH 4 HTR was observed, from 26.5 to 78.0% (p = 0.029). A reduction in esophageal pH acid clearance time and the total number of reflux events, including acid and proximal reflux events, were significantly reduced. Vonoprazan may be a better therapy for the treatment of patients with PPI-refractory RE. © 2017 S. Karger AG, Basel.

Urea application promotes amino acid metabolism and membrane lipid peroxidation in Azolla.

Science.gov (United States)

Chen, Jiana; Huang, Min; Cao, Fangbo; Pardha-Saradhi, P; Zou, Yingbin

2017-01-01

A pot experiment was conducted to evaluate the effect of urea on nitrogen metabolism and membrane lipid peroxidation in Azolla pinnata. Compared to controls, the application of urea to A. pinnata resulted in a 44% decrease in nitrogenase activity, no significant change in glutamine synthetase activity, 660% higher glutamic-pyruvic transaminase, 39% increase in free amino acid levels, 22% increase in malondialdehyde levels, 21% increase in Na+/K+- levels, 16% increase in Ca2+/Mg2+-ATPase levels, and 11% decrease in superoxide dismutase activity. In terms of H2O2 detoxifying enzymes, peroxidase activity did not change and catalase activity increased by 64% in urea-treated A. pinnata. These findings suggest that urea application promotes amino acid metabolism and membrane lipid peroxidation in A. pinnata.

Saturated fatty acid intake can influence increase in plasminogen activator inhibitor-1 in obese adolescents.

Science.gov (United States)

Masquio, D C L; de Piano, A; Campos, R M S; Sanches, P L; Corgosinho, F C; Carnier, J; Oyama, L M; do Nascimento, C M P O; de Mello, M T; Tufik, S; Dâmaso, A R

2014-04-01

The aim of this study was to verify if saturated fatty acid intake adjusted by tertiles can influence metabolic, inflammation, and plasminogen activator inhibitor-1 (PAI-1) in obese adolescents. Body mass, height, body mass index, waist circumference, blood pressure, and body composition of 108 obese adolescents were obtained. Fasting glucose, insulin, PAI-1, and CRP were determined. Insulin resistance was assessed by Homeostasis Model Assessment (HOMA-IR) and insulin sensitivity by Quantitative Insulin Sensitivity Check Index (QUICKI). Dietetic intake was estimated by a 3-day dietary record, and volunteers were divided according to consumption of saturated fatty acids: tertile 1 [Low Saturated Fatty Acid Intake (Low-SFA): ≤12.14 g], tertile 2 [Moderate Saturated Fatty Intake (Moderate SFA intake): 12.15-20.48 g], and tertile 3 [High Saturated Fatty Acid Intake (High-SFA Intake); >20.48 g]. Statistical analysis was performed using STATISTICA 7.0 software and the significance level was set at pstudy is that Moderate and High-SFA intakes presented significantly higher values of PAI-1 than Low-SFA Intake. PAI-1 was positively associated with saturated fatty intake, waist circumference, mean blood pressure, and HOMA-IR. SFA intake was predictor of PAI-1 independent of body fat, HOMA-IR and total-cholesterol. In addition, PAI-1 was an independent predictor of blood pressure. HOMA-IR and QUICKI presented significantly higher and lower, respectively, in High-SFA compared to Moderate-SFA intake. High-SFA influenced cardiovascular disease risks, since it increased PAI-1 and insulin resistance, and decreased insulin sensibility, leading to vicious cycle among food ingestion, pro-thrombotic state, and cardiovascular risks in obese adolescents. © Georg Thieme Verlag KG Stuttgart · New York.

Inhibitors of HIV-1 maturation: Development of structure-activity relationship for C-28 amides based on C-3 benzoic acid-modified triterpenoids.

Science.gov (United States)

Swidorski, Jacob J; Liu, Zheng; Sit, Sing-Yuen; Chen, Jie; Chen, Yan; Sin, Ny; Venables, Brian L; Parker, Dawn D; Nowicka-Sans, Beata; Terry, Brian J; Protack, Tricia; Rahematpura, Sandhya; Hanumegowda, Umesh; Jenkins, Susan; Krystal, Mark; Dicker, Ira B; Meanwell, Nicholas A; Regueiro-Ren, Alicia

2016-04-15

We have recently reported on the discovery of a C-3 benzoic acid (1) as a suitable replacement for the dimethyl succinate side chain of bevirimat (2), an HIV-1 maturation inhibitor that reached Phase II clinical trials before being discontinued. Recent SAR studies aimed at improving the antiviral properties of 2 have shown that the benzoic acid moiety conferred topographical constraint to the pharmacophore and was associated with a lower shift in potency in the presence of human serum albumin. In this manuscript, we describe efforts to improve the polymorphic coverage of the C-3 benzoic acid chemotype through modifications at the C-28 position of the triterpenoid core. The dimethylaminoethyl amides 17 and 23 delivered improved potency toward bevirimat-resistant viruses while increasing C24 in rat oral PK studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ethnicity and elevated liver transaminases among newly diagnosed children with type 2 diabetes

Directory of Open Access Journals (Sweden)

Hudson Omar D

2012-11-01

Full Text Available Abstract Background To examine the influence of ethnicity on liver transaminases among adolescents with type 2 diabetes mellitus (T2DM. Methods A retrospective medical chart review of 57 (30 males and 27 females newly diagnosed patients with T2DM. Ethnicity was determined by self-report and height, weight, body mass index (BMI and glycosylated hemoglobin (HbA1c were obtained using standard clinical procedures. Fasting levels of alanine aminotransaminase (ALT and aspartate aminotransferase (AST were collected prior to the initiation of any therapy. Results Age, gender, height, weight, BMI, and HbA1c did not differ between ethnic groups. Compared to African-Americans, Hispanics had significantly higher ALT (23.9 ± 3.4 vs. 107.8 ± 20.3, p=0.002 and AST (17.7 ± 2.5 vs. 71.1 ± 15.7, p Conclusions These preliminary findings suggest that Hispanic children with T2DM may be at higher risk for developing non-alcoholic fatty liver disease and indicate that a comprehensive hepatic evaluation is warranted in this population. Future studies that incorporate more precise and proximal measures of liver health are warranted in this population.

Corrosion inhibitors for neutral aqueous media based on the products on sugar cane processing. 1.Furfural derivatives as inhibitors

International Nuclear Information System (INIS)

Ledovskikh, V.M.; Kamekho Khinnebra, Kh.Kh.

1993-01-01

A series of carboxy-, nitrogen- and nitroderivaties of furfural - the main product of sugar cane processing (furancasboxylic acid, 5-nitrofurancarboxylic acid and its salts, furfurine, furfurylamine) was studied as inhibitors of iron and copper, corrosion in aqueous-salt media. Nitrofuroates of sodium and ammonium, which decelerate anode process, intensity cathode one and provide the stable passive state, are considered to be the most effective

Is there in vivo evidence for amino acid shuttles carrying ammonia from neurons to astrocytes?

Science.gov (United States)

Rothman, Douglas L; De Feyter, Henk M; Maciejewski, Paul K; Behar, Kevin L

2012-11-01

The high in vivo flux of the glutamate/glutamine cycle puts a strong demand on the return of ammonia released by phosphate activated glutaminase from the neurons to the astrocytes in order to maintain nitrogen balance. In this paper we review several amino acid shuttles that have been proposed for balancing the nitrogen flows between neurons and astrocytes in the glutamate/glutamine cycle. All of these cycles depend on the directionality of glutamate dehydrogenase, catalyzing reductive glutamate synthesis (forward reaction) in the neuron in order to capture the ammonia released by phosphate activated glutaminase, while catalyzing oxidative deamination of glutamate (reverse reaction) in the astrocytes to release ammonia for glutamine synthesis. Reanalysis of results from in vivo experiments using (13)N and (15)N labeled ammonia and (15)N leucine in rats suggests that the maximum flux of the alanine/lactate or branched chain amino acid/branched chain amino acid transaminase shuttles between neurons and astrocytes are approximately 3-5 times lower than would be required to account for the ammonia transfer from neurons to astrocytes needed for glutamine synthesis (amide nitrogen) to sustain the glutamate/glutamine cycle. However, in the rat brain both the total ammonia fixation rate by glutamate dehydrogenase and the total branched chain amino acid transaminase activity are sufficient to support a branched chain amino acid/branched chain keto acid shuttle, as proposed by Hutson and coworkers, which would support the de novo synthesis of glutamine in the astrocyte to replace the ~20 % of neurotransmitter glutamate that is oxidized. A higher fraction of the nitrogen needs of total glutamate neurotransmitter cycling could be supported by hybrid cycles in which glutamate and tricarboxylic acid cycle intermediates act as a nitrogen shuttle. A limitation of all in vivo studies in animals conducted to date is that none have shown transfer of nitrogen for glutamine amide

SCD1 inhibition causes cancer cell death by depleting mono-unsaturated fatty acids.

Directory of Open Access Journals (Sweden)

Paul Mason

Full Text Available Increased metabolism is a requirement for tumor cell proliferation. To understand the dependence of tumor cells on fatty acid metabolism, we evaluated various nodes of the fatty acid synthesis pathway. Using RNAi we have demonstrated that depletion of fatty-acid synthesis pathway enzymes SCD1, FASN, or ACC1 in HCT116 colon cancer cells results in cytotoxicity that is reversible by addition of exogenous fatty acids. This conditional phenotype is most pronounced when SCD1 is depleted. We used this fatty-acid rescue strategy to characterize several small-molecule inhibitors of fatty acid synthesis, including identification of TOFA as a potent SCD1 inhibitor, representing a previously undescribed activity for this compound. Reference FASN and ACC inhibitors show cytotoxicity that is less pronounced than that of TOFA, and fatty-acid rescue profiles consistent with their proposed enzyme targets. Two reference SCD1 inhibitors show low-nanomolar cytotoxicity that is offset by at least two orders of magnitude by exogenous oleate. One of these inhibitors slows growth of HCT116 xenograft tumors. Our data outline an effective strategy for interrogation of on-mechanism potency and pathway-node-specificity of fatty acid synthesis inhibitors, establish an unambiguous link between fatty acid synthesis and cancer cell survival, and point toward SCD1 as a key target in this pathway.

SCD1 inhibition causes cancer cell death by depleting mono-unsaturated fatty acids.

Science.gov (United States)

Mason, Paul; Liang, Beirong; Li, Lingyun; Fremgen, Trisha; Murphy, Erin; Quinn, Angela; Madden, Stephen L; Biemann, Hans-Peter; Wang, Bing; Cohen, Aharon; Komarnitsky, Svetlana; Jancsics, Kate; Hirth, Brad; Cooper, Christopher G F; Lee, Edward; Wilson, Sean; Krumbholz, Roy; Schmid, Steven; Xiang, Yibin; Booker, Michael; Lillie, James; Carter, Kara

2012-01-01

Increased metabolism is a requirement for tumor cell proliferation. To understand the dependence of tumor cells on fatty acid metabolism, we evaluated various nodes of the fatty acid synthesis pathway. Using RNAi we have demonstrated that depletion of fatty-acid synthesis pathway enzymes SCD1, FASN, or ACC1 in HCT116 colon cancer cells results in cytotoxicity that is reversible by addition of exogenous fatty acids. This conditional phenotype is most pronounced when SCD1 is depleted. We used this fatty-acid rescue strategy to characterize several small-molecule inhibitors of fatty acid synthesis, including identification of TOFA as a potent SCD1 inhibitor, representing a previously undescribed activity for this compound. Reference FASN and ACC inhibitors show cytotoxicity that is less pronounced than that of TOFA, and fatty-acid rescue profiles consistent with their proposed enzyme targets. Two reference SCD1 inhibitors show low-nanomolar cytotoxicity that is offset by at least two orders of magnitude by exogenous oleate. One of these inhibitors slows growth of HCT116 xenograft tumors. Our data outline an effective strategy for interrogation of on-mechanism potency and pathway-node-specificity of fatty acid synthesis inhibitors, establish an unambiguous link between fatty acid synthesis and cancer cell survival, and point toward SCD1 as a key target in this pathway.

Quantum Chemical Calculations and Molecular Docking Studies of Some NSAID Drugs (Aceclofenac, Salicylic Acid, and Piroxicam as 1PGE Inhibitors

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S. Suresh

2016-01-01

Full Text Available The molecular structure of the three compounds Aceclofenac (I, Salicylic Acid (II, and Piroxicam (III has been determined using Gaussian 03W program with B3LYP method using 6-311++G (d,p basis set calculations. The molecular structures were fully optimized with atomic numbering scheme adopted in the study. To understand the mode of binding and molecular interaction, the docking studies of compounds Aceclofenac (I, Salicylic Acid (II, and Piroxicam (III have been carried out with prostaglandin H2 synthase-1 (1PGE as target using induced fit docking. The molecular docking results show that the interactions and energy for Aceclofenac, Salicylic Acid, and Piroxicam show the best results when docked with prostaglandin H2 synthase-1 (1PGE. The hydrogen bonding interactions of compound I (Aceclofenac are prominent with Arginine moiety, those of compound II (Salicylic Acid are prominent with Tyrosine and Serine moieties, and compound III (Piroxicam shows such interaction with Tyrosine and Arginine moieties. These interactions of prostaglandin H2 synthase-1 (1PGE with substrates are responsible for governing COX-1 inhibitor potency which in turn is a direct measure of the potency of the drug.

Covalent docking of selected boron-based serine beta-lactamase inhibitors

Science.gov (United States)

Sgrignani, Jacopo; Novati, Beatrice; Colombo, Giorgio; Grazioso, Giovanni

2015-05-01

AmpC β-lactamase is a hydrolytic enzyme conferring resistance to β-lactam antibiotics in multiple Gram-negative bacteria. Therefore, identification of non-β-lactam compounds able to inhibit the enzyme is crucial for the development of novel antibacterial therapies. In general, AmpC inhibitors have to engage the highly solvent-exposed catalytic site of the enzyme. Therefore, understanding the implications of ligand-protein induced-fit and water-mediated interactions behind the inhibitor-enzyme recognition process is fundamental for undertaking structure-based drug design process. Here, we focus on boronic acids, a promising class of beta-lactamase covalent inhibitors. First, we optimized a docking protocol able to reproduce the experimentally determined binding mode of AmpC inhibitors bearing a boronic group. This goal was pursued (1) performing rigid and flexible docking calculations aiming to establish the role of the side chain conformations; and (2) investigating the role of specific water molecules in shaping the enzyme active site and mediating ligand protein interactions. Our calculations showed that some water molecules, conserved in the majority of the considered X-ray structures, are needed to correctly predict the binding pose of known covalent AmpC inhibitors. On this basis, we formalized our findings in a docking and scoring protocol that could be useful for the structure-based design of new boronic acid AmpC inhibitors.

A historical sketch of the discovery and development of HIV-1 integrase inhibitors.

Science.gov (United States)

Savarino, Andrea

2006-12-01

The long process of HIV-1 integrase inhibitor discovery and development can be attributed to both the complexity of HIV-1 integration and poor 'integration' of these researches into mainstream investigations on antiretroviral therapy in the mid-1990s. Of note, some fungal extracts investigated during this period contain the beta-hydroxyketo group, later recognised to be a key structural requirement for keto-enol acids (also referred to as diketo acids) and other integrase inhibitors. This review reconstructs (in the general context of the history of AIDS research) the principal steps that led to the integrase inhibitors currently in clinical trials, and discusses possible future directions.

Potent Inhibitors against Newcastle Disease Virus Hemagglutinin-Neuraminidase.

Science.gov (United States)

Rota, Paola; La Rocca, Paolo; Piccoli, Marco; Montefiori, Marco; Cirillo, Federica; Olsen, Lars; Orioli, Marica; Allevi, Pietro; Anastasia, Luigi

2018-02-06

Neuraminidase activity is essential for the infection and propagation of paramyxoviruses, including human parainfluenza viruses (hPIVs) and the Newcastle disease virus (NDV). Thus, many inhibitors have been developed based on the 2-deoxy-2,3-didehydro-d-N-acetylneuraminic acid inhibitor (DANA) backbone. Along this line, herein we report a series of neuraminidase inhibitors, having C4 (p-toluenesulfonamido and azido substituents) and C5 (N-perfluorinated chains) modifications to the DANA backbone, resulting in compounds with 5- to 15-fold greater potency than the currently most active compound, the N-trifluoroacetyl derivative of DANA (FANA), toward the NDV hemagglutinin-neuraminidase (NDV-HN). Remarkably, these inhibitors were found to be essentially inactive against the human sialidase NEU3, which is present on the outer layer of the cell membrane and is highly affected by the current NDV inhibitor FANA. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A preclinical study on the rescue of normal tissue by nicotinic acid in high-dose treatment with APO866, a specific nicotinamide phosphoribosyltransferase inhibitor

DEFF Research Database (Denmark)

Olesen, Uffe Høgh; Thougaard, Annemette V; Jensen, Peter Buhl

2010-01-01

Inhibitor of nicotinamide phosphoribosyltransferase APO866 is a promising cancer drug currently in phase II clinical trials in oncology. Here, we present a strategy for increasing the therapeutic potential of APO866 through the rescue of normal tissues by coadministration of nicotinic acid (Vitamin...... B(3)). We examined the toxicity profile of APO866 in B6D2F1 mice and the effect of oral administration of nicotinic acid on tissue toxicity. Nicotinic acid (50 mg/kg) protects mice from death and severe toxicity from an APO866 dose (60 mg/kg) four times the monotherapy maximum tolerated dose (15 mg....../kg). In a panel of six cancer cell lines, we find that three (including ML-2 cells) are protected by nicotinic acid in vitro, whereas the cytotoxicity of APO866 remains unaffected in the remaining three (including A2780 cells). A selective biomarker for the protection by nicotinic acid was subsequently identified...

Antifungal drugs as corrosion inhibitors for aluminium in 0.1 M HCl

Energy Technology Data Exchange (ETDEWEB)

Obot, I.B. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)], E-mail: proffoime@yahoo.com; Obi-Egbedi, N.O. [Department of Chemistry, University of Ibadan, Ibadan (Nigeria); Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)

2009-08-15

The inhibitive capabilities of Clotrimazole (CTM) and Fluconazole (FLC), two antifungal drugs, on the electrochemical corrosion of aluminium in 0.1 M HCl solution has been studied using weight loss measurements at 30 and 50 deg. C. The results indicate that both compound act as inhibitors in the acidic corrodent. At constant acid concentration, the inhibition efficiency (%I) increased with increase in the concentration of the inhibitors. Increase in temperature increased the corrosion rate in the absence and presence of the inhibitors but decreased the inhibition efficiency. CTM and FLC adsorbed on the surface of aluminium according to the Langmuir adsorption isotherm model at all the concentrations and temperatures studied. Phenomenon of physical adsorption is proposed from the activation parameter obtained. Thermodynamic parameters reveal that the adsorption process is spontaneous. The reactivity of these compounds was analyzed through theoretical calculations based on AM1 semi-empirical method to explain the different efficiencies of these compounds as corrosion inhibitors. CTM was found to be a better inhibitor than FLC.

Differential sensitivity of polyhydroxyalkanoate producing bacteria to fermentation inhibitors and comparison of polyhydroxybutyrate production from Burkholderia cepacia and Pseudomonas pseudoflava.

Science.gov (United States)

Dietrich, Diane; Illman, Barbara; Crooks, Casey

2013-06-04

The aim of this study is determine the relative sensitivity of a panel of seven polyhydroxyalkanoate producing bacteria to a panel of seven lignocellulosic-derived fermentation inhibitors representing aliphatic acids, furans and phenolics. A further aim was to measure the polyhydroxybutyrate production of select organisms on lignocellulosic-derived monosaccharides arabinose, xylose, glucose and mannose. We examined the sensitivity of seven polyhydroxyalkanoate producing bacteria: Azohydromonas lata, Bacillus megaterium, Bacillus cereus, Burkholderia cepacia, Pseudomonas olevorans, Pseudomonas pseudoflava and Ralstonia eutropha, against seven fermentation inhibitors produced by the saccharification of lignocellulose: acetic acid, levulinic acid, coumaric acid, ferulic acid, syringaldehyde, furfural, and hyroxymethyfurfural. There was significant variation in the sensitivity of these microbes to representative phenolics ranging from 0.25-1.5 g/L coumaric and ferulic acid and between 0.5-6.0 g/L syringaldehyde. Inhibition ranged from 0.37-4 g/L and 0.75-6 g/L with acetic acid and levulinic acid, respectively. B. cepacia and P. pseudoflava were selected for further analysis of polyhydroxyalkanoate production. We find significant differences in sensitivity to the fermentation inhibitors tested and find these variations to be over a relevant concentration range given the concentrations of inhibitors typically found in lignocellulosic hydrolysates. Of the seven bacteria tested, B. cepacia demonstrated the greatest inhibitor tolerance. Similarly, of two organisms examined for polyhydroxybutyrate production, B. cepacia was notably more efficient when fermenting pentose substrates.

Super-Hydrophobic Green Corrosion Inhibitor On Carbon Steel

Science.gov (United States)

Hassan, H.; Ismail, A.; Ahmad, S.; Soon, C. F.

2017-06-01

There are many examples of organic coatings used for corrosion protection. In particular, hydrophobic and super-hydrophobic coatings are shown to give good protection because of their enhanced ability to slow down transport of water and ions through the coating. The purpose of this research is to develop water repellent coating to avoid direct contact between metal and environment corrosive and mitigate corrosion attack at pipeline system. This water repellent characteristic on super-hydrophobic coating was coated by electrodeposition method. Wettability of carbon steel with super-hydrophobic coating (cerium chloride and myristic acid) and oxidized surface was investigated through contact angle and inhibitor performance test. The inhibitor performance was studied in 25% tannin acid corrosion test at 30°C and 3.5% sodium chloride (NaCl). The water contact angle test was determined by placing a 4-μL water droplet of distilled water. It shows that the wettability of contact angle super-hydrophobic with an angle of 151.60° at zero minute can be classified as super-hydrophobic characteristic. By added tannin acid as inhibitor the corrosion protection on carbon steel becomes more consistent. This reveals that the ability of the coating to withstand with the corrosion attack in the seawater at different period of immersions. The results elucidate that the weight loss increased as the time of exposure increased. However, the corrosion rates for uncoated carbon steel is high compared to coated carbon steel. As a conclusion, from both samples it can be seen that the coated carbon steel has less corrosion rated compared to uncoated carbon steel and addition of inhibitor to the seawater provides more protection to resist corrosion attack on carbon steel.

Detection of Hepatitis C virus RNA in peripheral blood mononuclear cells of patients with abnormal alanine transaminase in Ahvaz

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M Makvandi

2014-01-01

Full Text Available Purpose: Hepatitis C virus (HCV is an important agent for chronic and acute hepatitis. Occult hepatitis C remains a major health problem worldwide. Patients with chronic occult HCV may progress to cirrhosis and hepatocellular carcinoma. The aim of this study was to determine prevalence of occult hepatitis C by IS-PCR-ISH (in situ PCR in situ hybridisation in the patients with abnormal ALT. Materials and Methods: The blood samples were taken from 53 patients including 17 females (32.1% and 36 (67.9% males who had abnormal alanine transaminase (ALT for more than 1 year. The mean ALT and aspartate transaminase (AST level were 41.02 ± 9.3 and 24.17 ± 7.3, respectively. The patients′ age were between 4 and 70-years old with mean age 38 ± 13. All the patients were negative for HCV antibody, HCV RNA and HBs Ag. The peripheral blood mononuclear cells (PBMC were separated with ficoll gradient from each blood sample, then the cells were fixed on slides by cold acetone and followed by IS-PCR-ISH for HCV RNA detection. Results: Seventeen (32% patients including 6 (11.3% females and 11 (20.7% males showed positive results for HCV RNA by in situ-PCR in situ hybridisation. Ten (18.8% positive cases were between 20 and 40-years old and 6 (11.3% positive patients were between 40 and 60 years old. Ten (19.6% patients who were positive for IS-PCR-ISH also had positive anti-HBc IgG and 7 (13.2% patients were negative for HBc-IgG. Conclusion: In the present study high rate of 32% occult hepatitis C were found among the patients with elevated ALT.

Histone deacetylase inhibitors (HDACIs): multitargeted anticancer agents.

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Ververis, Katherine; Hiong, Alison; Karagiannis, Tom C; Licciardi, Paul V

2013-01-01

Histone deacetylase (HDAC) inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents) as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza) and depsipeptide (romidepsin, Istodax). More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the advancement of these drugs, especially to facilitate the rational design of HDAC inhibitors that are effective as antineoplastic agents. This review will discuss the use of HDAC inhibitors as multitargeted therapies for malignancy. Further, we outline the pharmacology and mechanisms of action of HDAC inhibitors while

Detoxification of acidic catalyzed hydrolysate of Kappaphycus alvarezii (cottonii).

Science.gov (United States)

Meinita, Maria Dyah Nur; Hong, Yong-Ki; Jeong, Gwi-Taek

2012-01-01

Red seaweed, Kappaphycus alvarezii, holds great promise for use in biofuel production due to its high carbohydrate content. In this study, we investigated the effect of fermentation inhibitors to the K. alvarezii hydrolysate on cell growth and ethanol fermentation. In addition, detoxification of fermentation inhibitors was performed to decrease the fermentation inhibitory effect. 5-Hydroxymethylfurfural and levulinic acid, which are liberated from acidic hydrolysis, was also observed in the hydrolysate of K. alvarezii. These compounds inhibited ethanol fermentation. In order to remove these inhibitors, activated charcoal and calcium hydroxide were introduced. The efficiency of activated charcoals was examined and over-liming was used to remove the inhibitors. Activated charcoal was found to be more effective than calcium hydroxide to remove the inhibitors. Detoxification by activated charcoal strongly improved the fermentability of dilute acid hydrolysate in the production of bioethanol from K. alvarezii with Saccharomyces cerevisiae. The optimal detoxifying conditions were found to be below an activated charcoal concentration of 5%.

Glutamate oxidation in astrocytes: Roles of glutamate dehydrogenase and aminotransferases

DEFF Research Database (Denmark)

McKenna, Mary C; Stridh, Malin H; McNair, Laura Frendrup

2016-01-01

to the presynaptic neurons as the nonexcitatory amino acid glutamine. The cycle was initially thought to function with a 1:1 ratio between glutamate released and glutamine taken up by neurons. However, studies of glutamate metabolism in astrocytes have shown that a considerable proportion of glutamate undergoes...... the enzymes that mediate this conversion. Methods include pharmacological tools such as the transaminase inhibitor aminooxyacetic acid, studies using GDH knockout mice, and siRNA-mediated knockdown of GDH in astrocytes. Studies in brain slices incubated with [15N]glutamate demonstrated activity of GDH......The cellular distribution of transporters and enzymes related to glutamate metabolism led to the concept of the glutamate–glutamine cycle. Glutamate is released as a neurotransmitter and taken up primarily by astrocytes ensheathing the synapses. The glutamate carbon skeleton is transferred back...

Hypolipidemic and hypoglycemic activities of a oleanolic acid derivative from Malva parviflora on streptozotocin-induced diabetic mice.

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Gutiérrez, Rosa Martha Pérez

2017-05-01

One new oleanolic acid derivative, 2α,3β,23α,29α tetrahydroxyolean-12(13)-en-28-oic acid (1) was isolated from the aerial parts of Malva parviflora. Their structure was characterized by spectroscopic methods. The hypolipidemic and hypoglycemic activities of 1 was analyzed in in streptozotocin (STZ)-nicotinamide-induced type 2 diabetes in mice (MD) and type 1 diabetes in streptozotocin-induced diabetic mice (SD). Triterpene was administered orally at doses of 20 mg/kg for 4 weeks. Organ weight, body weight, glucose, fasting insulin, cholesterol-related lipid profile parameters, glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase (SALP), glucokinase, hexokinase, glucose-6-phosphatase activities and glycogen in liver were measured after 4 weeks of treatment. The results indicated that 1 regulate glucose metabolism, lipid profile, lipid peroxidation, increased body weight, glucokinase and hexokinase activities inhibited triglycerides, total cholesterol, low density lipoproteins level, SGOT, SGPT, SALP, glycogen in liver and glucose-6-phosphatase. In addition, improvement of insulin resistance and protective effect for pancreatic β-cells, also 1 may changes the expression of pro-inflammatory cytokine (IL-6 and TNF-α levels) and enzymes (PAL2, COX-2, and LOX). The results suggest that 1 has hypolipidemic and hypoglycemic, anti-inflammatory, activities, improve insulin resistance and hepatic enzymes in streptozotocin-induced diabetic mice.

Validation of tautomeric and protomeric binding modes by free energy calculations. A case study for the structure based optimization of d-amino acid oxidase inhibitors

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Orgován, Zoltán; Ferenczy, György G.; Steinbrecher, Thomas; Szilágyi, Bence; Bajusz, Dávid; Keserű, György M.

2018-02-01

Optimization of fragment size d-amino acid oxidase (DAAO) inhibitors was investigated using a combination of computational and experimental methods. Retrospective free energy perturbation (FEP) calculations were performed for benzo[d]isoxazole derivatives, a series of known inhibitors with two potential binding modes derived from X-ray structures of other DAAO inhibitors. The good agreement between experimental and computed binding free energies in only one of the hypothesized binding modes strongly support this bioactive conformation. Then, a series of 1-H-indazol-3-ol derivatives formerly not described as DAAO inhibitors was investigated. Binding geometries could be reliably identified by structural similarity to benzo[d]isoxazole and other well characterized series and FEP calculations were performed for several tautomers of the deprotonated and protonated compounds since all these forms are potentially present owing to the experimental pKa values of representative compounds in the series. Deprotonated compounds are proposed to be the most important bound species owing to the significantly better agreement between their calculated and measured affinities compared to the protonated forms. FEP calculations were also used for the prediction of the affinities of compounds not previously tested as DAAO inhibitors and for a comparative structure-activity relationship study of the benzo[d]isoxazole and indazole series. Selected indazole derivatives were synthesized and their measured binding affinity towards DAAO was in good agreement with FEP predictions.

Biophysical and physicochemical methods differentiate highly ligand-efficient human D-amino acid oxidase inhibitors.

Science.gov (United States)

Lange, Jos H M; Venhorst, Jennifer; van Dongen, Maria J P; Frankena, Jurjen; Bassissi, Firas; de Bruin, Natasja M W J; den Besten, Cathaline; de Beer, Stephanie B A; Oostenbrink, Chris; Markova, Natalia; Kruse, Chris G

2011-10-01

Many early drug research efforts are too reductionist thereby not delivering key parameters such as kinetics and thermodynamics of target-ligand binding. A set of human D-Amino Acid Oxidase (DAAO) inhibitors 1-6 was applied to demonstrate the impact of key biophysical techniques and physicochemical methods in the differentiation of chemical entities that cannot be adequately distinguished on the basis of their normalized potency (ligand efficiency) values. The resulting biophysical and physicochemical data were related to relevant pharmacodynamic and pharmacokinetic properties. Surface Plasmon Resonance data indicated prolonged target-ligand residence times for 5 and 6 as compared to 1-4, based on the observed k(off) values. The Isothermal Titration Calorimetry-derived thermodynamic binding profiles of 1-6 to the DAAO enzyme revealed favorable contributions of both ΔH and ΔS to their ΔG values. Surprisingly, the thermodynamic binding profile of 3 elicited a substantially higher favorable contribution of ΔH to ΔG in comparison with the structurally closely related fused bicyclic acid 4. Molecular dynamics simulations and free energy calculations of 1, 3, and 4 led to novel insights into the thermodynamic properties of the binding process at an atomic level and in the different thermodynamic signatures of 3 and 4. The presented holistic approach is anticipated to facilitate the identification of compounds with best-in-class properties at an early research stage. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Mutants of GABA transaminase (POP2 suppress the severe phenotype of succinic semialdehyde dehydrogenase (ssadh mutants in Arabidopsis.

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Frank Ludewig

Full Text Available BACKGROUND: The gamma-aminubutyrate (GABA shunt bypasses two steps of the tricarboxylic acid cycle, and is present in both prokaryotes and eukaryotes. In plants, the pathway is composed of the calcium/calmodulin-regulated cytosolic enzyme glutamate decarboxylase (GAD, the mitochondrial enzymes GABA transaminase (GABA-T; POP2 and succinic semialdehyde dehydrogenase (SSADH. We have previously shown that compromising the function of the GABA-shunt, by disrupting the SSADH gene of Arabidopsis, causes enhanced accumulation of reactive oxygen intermediates (ROIs and cell death in response to light and heat stress. However, to date, genetic investigations of the relationships between enzymes of the GABA shunt have not been reported. PRINCIPAL FINDINGS: To elucidate the role of succinic semialdehyde (SSA, gamma-hydroxybutyrate (GHB and GABA in the accumulation of ROIs, we combined two genetic approaches to suppress the severe phenotype of ssadh mutants. Analysis of double pop2 ssadh mutants revealed that pop2 is epistatic to ssadh. Moreover, we isolated EMS-generated mutants suppressing the phenotype of ssadh revealing two new pop2 alleles. By measuring thermoluminescence at high temperature, the peroxide contents of ssadh and pop2 mutants were evaluated, showing that only ssadh plants accumulate peroxides. In addition, pop2 ssadh seedlings are more sensitive to exogenous SSA or GHB relative to wild type, because GHB and/or SSA accumulate in these plants. SIGNIFICANCE: We conclude that the lack of supply of succinate and NADH to the TCA cycle is not responsible for the oxidative stress and growth retardations of ssadh mutants. Rather, we suggest that the accumulation of SSA, GHB, or both, produced downstream of the GABA-T transamination step, is toxic to the plants, resulting in high ROI levels and impaired development.

Study of a Triazole Derivative as Corrosion Inhibitor for Mild Steel in Phosphoric Acid Solution

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Lin Wang

2012-01-01

Full Text Available The corrosion inhibition by a triazole derivative (PAMT on mild steel in phosphoric acid (H3PO4 solution has been investigated by weight loss and polarization methods. The experimental results reveal that the compound has a significant inhibiting effect on the corrosion of steel in H3PO4 solution. It also shows good corrosion inhibition at higher concentration of H3PO4. Potentiodynamic polarization studies have shown that the compound acts as a mixed-type inhibitor retarding the anodic and cathodic corrosion reactions with predominant effect on the cathodic reaction. The values of inhibition efficiency obtained from weight loss and polarization measurements are in good agreement. The adsorption of this compound is found to obey the Langmuir adsorption isotherm. Some kinetic and thermodynamic parameters such as apparent activation energy, frequency factor, and adsorption free energy have been calculated and discussed.

Urea application promotes amino acid metabolism and membrane lipid peroxidation in Azolla.

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Jiana Chen

Full Text Available A pot experiment was conducted to evaluate the effect of urea on nitrogen metabolism and membrane lipid peroxidation in Azolla pinnata. Compared to controls, the application of urea to A. pinnata resulted in a 44% decrease in nitrogenase activity, no significant change in glutamine synthetase activity, 660% higher glutamic-pyruvic transaminase, 39% increase in free amino acid levels, 22% increase in malondialdehyde levels, 21% increase in Na+/K+- levels, 16% increase in Ca2+/Mg2+-ATPase levels, and 11% decrease in superoxide dismutase activity. In terms of H2O2 detoxifying enzymes, peroxidase activity did not change and catalase activity increased by 64% in urea-treated A. pinnata. These findings suggest that urea application promotes amino acid metabolism and membrane lipid peroxidation in A. pinnata.

Isolation and Characterization of an α-Glucosidase Inhibitor from Musa spp. (Baxijiao Flowers

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Zhanwu Sheng

2014-07-01

Full Text Available The use of α-glucosidase inhibitors is considered to be an effective strategy in the treatment of diabetes. Using a bioassay-guided fractionation technique, five Bacillus stearothermophilus α-glucosidase inhibitors were isolated from the flowers of Musa spp. (Baxijiao. Using NMR spectroscopy analysis they were identified as vanillic acid (1, ferulic acid (2, β-sitosterol (3, daucosterol (4 and 9-(4′-hydroxyphenyl-2-methoxyphenalen-1-one (5. The half maximal inhibitory concentration (IC50 values of compounds 1–5 were 2004.58, 1258.35, 283.67, 247.35 and 3.86 mg/L, respectively. Compared to a known α-glucosidase inhibitor (acarbose, IC50 = 999.31 mg/L, compounds 3, 4 and 5 showed a strong α-glucosidase inhibitory effect. A Lineweaver-Burk plot indicated that compound 5 is a mixed-competitive inhibitor, while compounds 3 and 4 are competitive inhibitors. The inhibition constants (Ki of compounds 3, 4 and 5 were 20.09, 2.34 and 4.40 mg/L, respectively. Taken together, these data show that the compounds 3, 4 and 5 are potent α-glucosidase inhibitors.

Are phloem-derived amino acids the origin of the elevated malate concentration in the xylem sap following mineral N starvation in soybean?

Science.gov (United States)

Vitor, Simone C; do Amarante, Luciano; Sodek, Ladaslav

2018-05-16

A substantial increase in malate in the xylem sap of soybean subjected to mineral N starvation originates mainly from aspartate, a prominent amino acid of the phloem. A substantial increase in xylem malate was found when non-nodulated soybean plants were transferred to a N-free medium. Nodulated plants growing in the absence of mineral N and, therefore, dependent on symbiotic N 2 fixation also contained elevated concentrations of malate in the xylem sap. When either nitrate or ammonium was supplied, malate concentrations in the xylem sap were low, both for nodulated and non-nodulated plants. Evidence was obtained that the elevated malate concentration of the xylem was derived from amino acids supplied by the phloem. Aspartate was a prominent component of the phloem sap amino acids and, therefore, a potential source of malate. Supplying the roots of intact plants with 13 C-aspartate revealed that malate of the xylem sap was readily labelled under N starvation. A hypothetical scheme is proposed whereby aspartate supplied by the phloem is metabolised in the roots and the products of this metabolism cycled back to the shoot. Under N starvation, aspartate metabolism is diverted from asparagine synthesis to supply N for the synthesis of other amino acids via transaminase activity. The by-product of aspartate transaminase activity, oxaloacetate, is transformed to malate and its export accounts for much of the elevated concentration of malate found in the xylem sap. This mechanism represents a new additional role for malate during mineral N starvation of soybean, beyond that of charge balance.

Eco-Friendly Inhibitors for Copper Corrosion in Nitric Acid: Experimental and Theoretical Evaluation

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Savita; Mourya, Punita; Chaubey, Namrata; Singh, V. K.; Singh, M. M.

2016-02-01

The inhibitive performance of Vitex negundo, Adhatoda vasica, and Saraka asoka leaf extracts on corrosion of copper in 3M HNO3 solution was investigated using gravimetric, potentiodynamic polarization, and electrochemical impedance spectroscopic techniques. Potentiodynamic polarization studies indicated that these extracts act as efficient and predominantly cathodic mixed inhibitor. Thermodynamic parameters revealed that the adsorption of these inhibitors on copper surface was spontaneous, controlled by physiochemical processes and occurred according to the Langmuir adsorption isotherm. AFM examination of copper surface confirmed that the inhibitor prevented corrosion by forming protective layer on its surface. The correlation between inhibitive effect and molecular structure was ascertained by density functional theory data.

The Fatty Acid Synthase Inhibitor Platensimycin Improves Insulin Resistance without Inducing Liver Steatosis in Mice and Monkeys.

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Sheo B Singh

Full Text Available Platensimycin (PTM is a natural antibiotic produced by Streptomyces platensis that selectively inhibits bacterial and mammalian fatty acid synthase (FAS without affecting synthesis of other lipids. Recently, we reported that oral administration of PTM in mouse models (db/db and db/+ with high de novo lipogenesis (DNL tone inhibited DNL and enhanced glucose oxidation, which in turn led to net reduction of liver triglycerides (TG, reduced ambient glucose, and improved insulin sensitivity. The present study was conducted to explore translatability and the therapeutic potential of FAS inhibition for the treatment of diabetes in humans.We tested PTM in animal models with different DNL tones, i.e. intrinsic synthesis rates, which vary among species and are regulated by nutritional and disease states, and confirmed glucose-lowering efficacy of PTM in lean NHPs with quantitation of liver lipid by MRS imaging. To understand the direct effect of PTM on liver metabolism, we performed ex vivo liver perfusion study to compare FAS inhibitor and carnitine palmitoyltransferase 1 (CPT1 inhibitor.The efficacy of PTM is generally reproduced in preclinical models with DNL tones comparable to humans, including lean and established diet-induced obese (eDIO mice as well as non-human primates (NHPs. Similar effects of PTM on DNL reduction were observed in lean and type 2 diabetic rhesus and lean cynomolgus monkeys after acute and chronic treatment of PTM. Mechanistically, PTM lowers plasma glucose in part by enhancing hepatic glucose uptake and glycolysis. Teglicar, a CPT1 inhibitor, has similar effects on glucose uptake and glycolysis. In sharp contrast, Teglicar but not PTM significantly increased hepatic TG production, thus caused liver steatosis in eDIO mice.These findings demonstrate unique properties of PTM and provide proof-of-concept of FAS inhibition having potential utility for the treatment of diabetes and related metabolic disorders.

INHIBITION OF CORROSION OF ZINC IN (HNO3 + HCl) ACID ...

African Journals Online (AJOL)

2015-05-01

May 1, 2015 ... corrosion inhibitor for zinc in phosphoric acid. Vashi et al.[8-9] studied the corrosion inhibition of zinc in (HNO3 + H2SO4) and (HNO3 + H3PO4) binary acid mixture by aniline. In the present work, the role of aniline as inhibitor for corrosion of zinc in (HNO3 + HCl) binary acid mixture has been reported. 2.

Plasma plasminogen activator inhibitor-1 levels and nonalcoholic fatty liver in individuals with features of metabolic syndrome.

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de Larrañaga, Gabriela; Wingeyer, Silvia Perés; Graffigna, Mabel; Belli, Susana; Bendezú, Karla; Alvarez, Silvia; Levalle, Oscar; Fainboim, Hugo

2008-07-01

Fatty liver represents the liver component of metabolic syndrome and may be involved in plasminogen activator inhibitor-1 (PAI-1) synthesis. We studied plasma PAI-1 levels and relationships with risk factors for metabolic syndrome, including fatty liver, in 170 patients. Liver ultrasound scan was performed on all patients, and a liver biopsy was performed on those patients with chronically elevated transaminase levels. Plasma PAI-1 levels correlated significantly (P < .05) with body mass index, degree of steatosis, insulin resistance, insulin level, waist circumference, triglycerides, and high-density lipoprotein (HDL) -cholesterol. However, only body mass index (beta = .455) and HDL-cholesterol (beta = .293) remained predictors of PAI-1 levels. Liver biopsy revealed a significant correlation (P < .05) between insulin resistance (r = 0.381) or insulin level (r = 0.519) and liver fibrosis. In patients presenting features of metabolic syndrome, plasma PAI-1 levels were mainly conditioned by the whole-body fat content.

Identification of a macromolecular crystal growth inhibitor in human urine as osteopontin

DEFF Research Database (Denmark)

Sørensen, Steen; Justesen, S J; Johnsen, A H

1995-01-01

, an unidentified protein rich in uronic acid, and uropontin have all been described as possessing such activity. We have recently isolated an unknown inhibitor of calcium oxalate crystal growth that co-eluted with trypsin inhibitor in several separation steps, which suggested its identity. The aim of the present......Macromolecules occurring in human urine inhibit the growth and/or aggregation of calcium oxalate crystals and may prevent the formation of kidney stones. Attention has focused particularly on proteins, as these seem to be most responsible for the inhibitory activity; three proteins, nephrocalcin...... study was to outline a simple procedure for isolating and identifying this inhibitor. Purification was done as follows: precipitation of the major proteins (albumin and uromucoid) with trichloroacetic acid, followed by anion exchange chromatography, hydroxyapatite chromatography, anion exchange...

Inhibitors of amino acids biosynthesis as antifungal agents.

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Jastrzębowska, Kamila; Gabriel, Iwona

2015-02-01

Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.

Discovery and development of inhibitors selective for human constitutive proteasome and immunoproteasome active sites

NARCIS (Netherlands)

Xin, B.

2017-01-01

This thesis describes the design and development of subunit‐selective inhibitors of particular catalytically active subunits of human constitutive proteasomes and immunoproteasomes. Most existing proteasome inhibitors are oligopeptides composed of 2‐4 amino acid residues, N‐terminally

Discovery of a novel acyl-CoA: cholesterol acyltransferase inhibitor: the synthesis, biological evaluation, and reduced adrenal toxicity of (4-phenylcoumarin)acetanilide derivatives with a carboxylic acid moiety.

Science.gov (United States)

Ogino, Masaki; Nakada, Yoshihisa; Negoro, Nobuyuki; Itokawa, Shigekazu; Nishimura, Satoshi; Sanada, Tsukasa; Satomi, Tomoko; Kita, Shunbun; Kubo, Kazuki; Marui, Shogo

2011-01-01

As a part of our research for novel potent and orally available acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors that can be used as anti-atherosclerotic agents, we recently reported the discovery of the (4-phenylcoumarine)acetanilide derivative 1. However, compound 1 showed adrenal toxicity in animal models. In order to search for safer ACAT inhibitors that do not have adrenal toxicity, we examined the inhibitory activity of ACAT in human macrophage and adrenal cells. The introduction of a carboxylic acid moiety on the pendant phenyl ring and the adjustment of the lipophilicity led to the discovery of (2E)-3-[7-chloro-3-[2-[[4-fluoro-2-(trifluoromethyl)phenyl]amino]-2-oxoethyl]-6-methyl-2-oxo-2H-chromen-4-yl]phenyl]acrylic acid (21e), which showed potent ACAT inhibitory activity in macrophages and a selectivity of around 30-fold over adrenal cells. In addition, compound 21e showed high adrenal safety in guinea pigs.

Expression patterns of nicotinamide phosphoribosyltransferase and nicotinic acid phosphoribosyltransferase in human malignant lymphomas

DEFF Research Database (Denmark)

Olesen, Uffe Høgh; Hastrup, Nina; Sehested, Maxwell

2011-01-01

The purpose of the study was to determine in human malignant lymphomas the expression patterns of nicotinamide phosphoribosyltransferase (NAMPT) and nicotinic acid phosphoribosyltransferase (NAPRT), the primary, rate-limiting enzymes in the synthesis of NAD+. NAMPT is a potential biomarker...... for sensitivity to NAMPT inhibitors and NAPRT is a biomarker for the use of nicotinic acid as a chemoprotectant in treatment with NAMPT inhibitors. The NAMPT inhibitor, APO866, is currently in clinical phase II trials in lymphomas. The expression of NAMPT and NAPRT was investigated in 53 samples of malignant.......0024). In conclusion, FL are a promising target for NAMPT inhibitors whereas substantial subsets of malignant lymphomas especially in Hodgkin lymphoma may be suitable for a combination treatment with nicotinic acid and NAMPT inhibitors....

Lysophosphatidylcholines containing polyunsaturated fatty acids were found as Na+,K+-ATPase inhibitors in acutely volume-expanded hog

International Nuclear Information System (INIS)

Tamura, M.; Harris, T.M.; Higashimori, K.; Sweetman, B.J.; Blair, I.A.; Inagami, T.

1987-01-01

Na + ,K + -ATPase inhibitors activities against the specific binding of ouabain to Na + ,K + -ATPase and 86 Rb uptake into hog erythrocytes have been purified from the plasma of acutely saline-infused hog. The purifications were performed by a combination of Amberlite XAD-2 adsorption chromatography and four steps of high-performance liquid chromatography with four different types of columns. Fast atom bombardment (FAB) mass and proton NMR spectrometric studies identified the purified substances as γ-arachidoyl- [LPCA(γ), 34%], β-arachidoyl- [LPCA(β), 4%], γ-linoleoyl- (LPCL, 33%), and γ-oleoyl- (LPCO, 25%) lysophosphatidylcholine, expressed in molar ratio in the plasma. Small amounts of γ-docosapentaenoyl-, γ-eicosatrienoyl-, and γpalmitoyllysophosphatidylcholine were also detected by both FAB mass and 1 H NMR spectrometric studies. The inhibition of Na + ,K + -ATPase activity due to these compounds was always more sensitive than that of both ouabain-binding and 86 Rb uptake activities. The ouabain-displacing activity in plasma due to these compounds increased with time during saline infusion. The maximal plasma level was approximately 10 times higher than that in the preinfusion plasma sample. Although these results suggest that γ-acyl-LPC's with long-chain polyunsaturated fatty acids are not simple competitive inhibitors to Na + ,K + -ATPase, these compounds could be implicated in the pathogenesis of the circulation abnormality through the modulation of membrane enzyme

Activation loop targeting strategy for design of receptor-interacting protein kinase 2 (RIPK2) inhibitors.

Science.gov (United States)

Suebsuwong, Chalada; Pinkas, Daniel M; Ray, Soumya S; Bufton, Joshua C; Dai, Bing; Bullock, Alex N; Degterev, Alexei; Cuny, Gregory D

2018-02-15

Development of selective kinase inhibitors remains a challenge due to considerable amino acid sequence similarity among family members particularly in the ATP binding site. Targeting the activation loop might offer improved inhibitor selectivity since this region of kinases is less conserved. However, the strategy presents difficulties due to activation loop flexibility. Herein, we report the design of receptor-interacting protein kinase 2 (RIPK2) inhibitors based on pan-kinase inhibitor regorafenib that aim to engage basic activation loop residues Lys169 or Arg171. We report development of CSR35 that displayed >10-fold selective inhibition of RIPK2 versus VEGFR2, the target of regorafenib. A co-crystal structure of CSR35 with RIPK2 revealed a resolved activation loop with an ionic interaction between the carboxylic acid installed in the inhibitor and the side-chain of Lys169. Our data provides principle feasibility of developing activation loop targeting type II inhibitors as a complementary strategy for achieving improved selectivity. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Substituted 2-Acylaminocycloalkylthiophene-3-carboxylic Acid Arylamides as Inhibitors of the Calcium-Activated Chloride Channel Transmembrane Protein 16A (TMEM16A).

Science.gov (United States)

Truong, Eric C; Phuan, Puay W; Reggi, Amanda L; Ferrera, Loretta; Galietta, Luis J V; Levy, Sarah E; Moises, Alannah C; Cil, Onur; Diez-Cecilia, Elena; Lee, Sujin; Verkman, Alan S; Anderson, Marc O

2017-06-08

Transmembrane protein 16A (TMEM16A), also called anoctamin 1 (ANO1), is a calcium-activated chloride channel expressed widely mammalian cells, including epithelia, vascular smooth muscle tissue, electrically excitable cells, and some tumors. TMEM16A inhibitors have been proposed for treatment of disorders of epithelial fluid and mucus secretion, hypertension, asthma, and possibly cancer. Herein we report, by screening, the discovery of 2-acylaminocycloalkylthiophene-3-carboxylic acid arylamides (AACTs) as inhibitors of TMEM16A and analysis of 48 synthesized analogs (10ab-10bw) of the original AACT compound (10aa). Structure-activity studies indicated the importance of benzene substituted as 2- or 4-methyl, or 4-fluoro, and defined the significance of thiophene substituents and size of the cycloalkylthiophene core. The most potent compound (10bm), which contains an unusual bromodifluoroacetamide at the thiophene 2-position, had IC 50 of ∼30 nM, ∼3.6-fold more potent than the most potent previously reported TMEM16A inhibitor 4 (Ani9), and >10-fold improved metabolic stability. Direct and reversible inhibition of TMEM16A by 10bm was demonstrated by patch-clamp analysis. AACTs may be useful as pharmacological tools to study TMEM16A function and as potential drug development candidates.

Molecular structure, spectroscopic and docking analysis of 1,3-diphenylpyrazole-4-propionic acid: A good prostaglandin reductase inhibitor

Science.gov (United States)

Kavitha, T.; Velraj, G.

2018-03-01

The molecule 1,3-diphenylpyrazole-4-propionic acid (DPPA) was optimized to its minimum energy level using density functional theory (DFT) calculations. The vibrational frequencies of DPPA were calculated along with their potential energy distribution (PED) and the obtained values are validated with the help of experimental calculations. The reactivity nature of the molecule was investigated with the aid of various DFT methods such as global reactivity descriptors, local reactivity descriptors, molecular electrostatic potential (MEP), natural bond orbitals (NBOs), etc. The prediction of activity spectra for substances (PASS) result forecast that, DPPA can be more active as a prostaglandin (PG) reductase inhibitor. The PGs are biologically synthesized by the cyclooxygenase (COX) enzyme which exists in COX1 and COX2 forms. The PGs produced by COX2 enzyme induces inflammation and fungal infections and hence the inhibition of COX2 enzyme is indispensable in anti-inflammation and anti-fungal activities. The docking analysis of DPPA with COX enzymes (both COX1 and COX2) were carried out and eventually, it was found that DPPA can selectively inhibit COX2 enzyme and can serve as a PG reductase inhibitor thereby acting as a lead compound for the treatment of inflammation and fungal diseases.

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.)

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.

Radiation-induced G/sub 2/-arrest is reduced by inhibitors of poly(adenosine diphosphoribose) synthetase

International Nuclear Information System (INIS)

Rowley, R.

1985-01-01

Experiments are in progress to test whether poly(adenosine diphosphoribose) synthesis is required for the induction of G/sub 2/-arrest in growing mammalian cells following X-irradiation. A variety of poly(ADPR) synthetase inhibitors have been tested to determine: 1) whether addition of an inhibitor to X-irradiated CHO cells reduces G/sub 2/-arrest; 2) whether compounds structurally similar to poly-(ADPR) synthetase inhibitors but inactive against this enzyme affect radiation-induced G/sub 2/-arrest and 3) whether the concentration dependence for poly(ADPR) synthetase inhibition matches that for G/sub 2/-arrest reduction. G/sub 2/-arrest was measured in X-irradiated (1.5 Gy) CHO cells using the mitotic cell selection technique. Poly(ADPR) synthetase activity was measured in permeabilized cells by /sup 3/H-NAD incorporation. The synthetase inhibitors used were 3-aminobenzamide, benzamide, nicotinamide, 4-acetyl pyridine, caffeine and theophylline. The inactive compounds used were 3-aminobenzoic acid, benzoic acid, nicotinic acid, adenine, adenosine and 3'-deoxyadenosine. Inhibitors of poly(ADPR) synthetase reduced G/sub 2/-arrest while related compounds which produced no enzyme inhibition did not. The concentration dependencies for G/sub 2/-arrest reduction and enzyme inhibition were similar only for methyl xanthines. Further analysis awaits the determination of intracellular drug concentrations

Molecular modeling of human acidic mammalian chitinase in complex with the natural-product cyclopentapeptide chitinase inhibitor argifin.

Science.gov (United States)

Gouda, Hiroaki; Terashima, Shinichi; Iguchi, Kanami; Sugawara, Akihiro; Saito, Yoshifumi; Yamamoto, Tsuyoshi; Hirose, Tomoyasu; Shiomi, Kazuro; Sunazuka, Toshiaki; Omura, Satoshi; Hirono, Shuichi

2009-09-01

Human acidic mammalian chitinase (hAMCase) is an attractive target for developing anti-asthma medications. We used a variety of computational methods to investigate the interaction between hAMCase and the natural-product cyclopentapeptide chitinase inhibitor argifin. The three-dimensional structure of hAMCase was first constructed using homology modeling. The interaction mode and binding free energy between argifin and hAMCase were then examined by the molecular-docking calculation and the molecular mechanics Poisson-Boltzmann surface area method combined with molecular dynamics simulation, respectively. The results suggested that argifin binds to hAMCase in a similar fashion to the interaction mode observed in the crystal structure of argifin-human chitotriosidase complex, and possesses inhibitory activity against hAMCase in the micromolar range. We further designed argifin derivatives expected to be selective for hAMCase.

Metabolism of organic acids, nitrogen and amino acids in chlorotic leaves of 'Honeycrisp' apple (Malus domestica Borkh) with excessive accumulation of carbohydrates.

Science.gov (United States)

Wang, Huicong; Ma, Fangfang; Cheng, Lailiang

2010-07-01

Metabolite profiles and activities of key enzymes in the metabolism of organic acids, nitrogen and amino acids were compared between chlorotic leaves and normal leaves of 'Honeycrisp' apple to understand how accumulation of non-structural carbohydrates affects the metabolism of organic acids, nitrogen and amino acids. Excessive accumulation of non-structural carbohydrates and much lower CO(2) assimilation were found in chlorotic leaves than in normal leaves, confirming feedback inhibition of photosynthesis in chlorotic leaves. Dark respiration and activities of several key enzymes in glycolysis and tricarboxylic acid (TCA) cycle, ATP-phosphofructokinase, pyruvate kinase, citrate synthase, aconitase and isocitrate dehydrogenase were significantly higher in chlorotic leaves than in normal leaves. However, concentrations of most organic acids including phosphoenolpyruvate (PEP), pyruvate, oxaloacetate, 2-oxoglutarate, malate and fumarate, and activities of key enzymes involved in the anapleurotic pathway including PEP carboxylase, NAD-malate dehydrogenase and NAD-malic enzyme were significantly lower in chlorotic leaves than in normal leaves. Concentrations of soluble proteins and most free amino acids were significantly lower in chlorotic leaves than in normal leaves. Activities of key enzymes in nitrogen assimilation and amino acid synthesis, including nitrate reductase, glutamine synthetase, ferredoxin and NADH-dependent glutamate synthase, and glutamate pyruvate transaminase were significantly lower in chlorotic leaves than in normal leaves. It was concluded that, in response to excessive accumulation of non-structural carbohydrates, glycolysis and TCA cycle were up-regulated to "consume" the excess carbon available, whereas the anapleurotic pathway, nitrogen assimilation and amino acid synthesis were down-regulated to reduce the overall rate of amino acid and protein synthesis.

Glutamine synthetase and alanine transaminase expression are decreased in livers of aged vs. young beef cows and GS can be upregulated by 17β-estradiol implants.

Science.gov (United States)

Miles, E D; McBride, B W; Jia, Y; Liao, S F; Boling, J A; Bridges, P J; Matthews, J C

2015-09-01

Aged beef cows (≥ 8 yr of age) produce calves with lower birth and weaning weights. In mammals, aging is associated with reduced hepatic expression of glutamine synthetase (GS) and alanine transaminase (ALT), thus impaired hepatic Gln-Glu cycle function. To determine if the relative protein content of GS, ALT, aspartate transaminase (AST), glutamate transporters (EAAC1, GLT-1), and their regulating protein (GTRAP3-18) differed in biopsied liver tissue of (a) aged vs. young (3 to 4 yr old) nonlactating, nongestating Angus cows (Exp. 1 and 2) and (b) aged mixed-breed cows with and without COMPUDOSE (17β-estradiol) ear implants (Exp. 3), Western blot analyses were performed. In Exp. 1, 12 young (3.62 ± 0.01 yr) and 13 aged (10.08 ± 0.42 yr) cows grazed the same mixed forage for 42 d (August-October). In Exp. 2, 12 young (3.36 ± 0.01 yr) and 12 aged (10.38 ± 0.47 yr) cows were individually fed (1.03% of BW) a corn-silage-based diet to maintain BW for 20 d. For both Exp. 1 and 2, the effect of cow age was assessed by ANOVA using the MIXED procedure of SAS. Cow BW did not change ( ≥ 0.17). Hepatic ALT (78% and 61%) and GS (52% and 71%) protein content (Exp. 1 and 2, respectively) was decreased ( ≤ 0.01), whereas GTRAP3-18 (an inhibitor of EAAC1 activity) increased ( ≤ 0.01; 170% and 136%) and AST, GLT-1, and EAAC1 contents did not differ ( ≥ 0.17) in aged vs. young cows. In Exp. 2, free concentrations (nmol/g) of Glu, Ala, Gln, Arg, and Orn in liver homogenates were determined. Aged cows tended to have less ( = 0.10) free Gln (15.0%) than young cows, whereas other AA concentrations did not differ ( 0.26). In Exp. 3, 14 aged (> 10 yr) cows were randomly allotted ( = 7) to sham or COMPUDOSE (25.7 mg of 17β-estradiol) implant treatment (TRT), and had ad libitum access to alfalfa hay for 28 d. Blood and liver biopsies were collected 14 and 28 d after implant treatment. Treatment, time after implant (DAY), and TRT × DAY effects were assessed by ANOVA using

O-Alkyl Hydroxamates as Metaphors of Enzyme-Bound Enolate Intermediates in Hydroxy Acid Dehydrogenases. Inhibitors of Isopropylmalate Dehydrogenase, Isocitrate Dehydrogenase, and Tartrate Dehydrogenase(1).

Science.gov (United States)

Pirrung, Michael C.; Han, Hyunsoo; Chen, Jrlung

1996-07-12

The inhibition of Thermus thermophilus isopropylmalate dehydrogenase by O-methyl oxalohydroxamate was studied for comparison to earlier results of Schloss with the Salmonella enzyme. It is a fairly potent (1.2 &mgr;M), slow-binding, uncompetitive inhibitor against isopropylmalate and is far superior to an oxamide (25 mM K(i) competitive) that is isosteric with the ketoisocaproate product of the enzyme. This improvement in inhibition was attributed to its increased NH acidity, which presumably is due to the inductive effect of the hydroxylamine oxygen. This principle was extended to the structurally homologous enzyme isocitrate dehydrogenase from E. coli, for which the compound O-(carboxymethyl) oxalohydroxamate is a 30 nM inhibitor, uncompetitive against isocitrate. The pH dependence of its inhibition supports the idea that it is bound to the enzyme in the anionic form. Another recently discovered homologous enzyme, tartrate dehydrogenase from Pseudomonas putida, was studied with oxalylhydroxamate. It has a relatively low affinity for the enzyme, though it is superior to tartrate. On the basis of these leads, squaric hydroxamates with increased acidity compared to squaric amides directed toward two of these enzymes were prepared, and they also show increased inhibitory potency, though not approaching the nanomolar levels of the oxalylhydroxamates.

Dissolution properties of cerium dibutylphosphate corrosion inhibitors

NARCIS (Netherlands)

Soestbergen, van M.; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

2013-01-01

The corrosion inhibitor cerium dibutylphosphate, Ce(dbp)3, prevents corrosion by cerium and dbp deposition at the alkaline cathode and acidic anode respectively. The pH dependent Ce(dbp)3 solubility seems to play an essential role in the inhibition degree. We found that Ce(dbp)3 scarcely dissolves

Development of new corrosion inhibitor tested on mild steel supported by electrochemical study

Science.gov (United States)

Habeeb, Hussein Jwad; Luaibi, Hasan Mohammed; Dakhil, Rifaat Mohammed; Kadhum, Abdul Amir H.; Al-Amiery, Ahmed A.; Gaaz, Tayser Sumer

2018-03-01

Mild steel is a metal which is commonly used in industrials and manufacturing of equipment for most industries round the world. It is cheaper cost compared with the other metals and its durable, hard and easy-to-wear physical properties make it a major choice in the manufacture of equipment parts. The main problem through the uses of mild steel in industry is its resistance against corrosion, especially in acidic solutions. This case led to raise the cost of maintenance of equipment that used mild steel and as a result increased costs for the company. Organic corrosive inhibitors that also act as green chemicals, 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol have been synthesized. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution (HCl) using electrochemical measurements test includes PD (Potentiodynamic), EIS (Electrochemical impedance spectroscopy), OCP (Open circuit potential) and EFM (electrochemical frequency modulation). The obtained results indicate that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol acts as a good corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the impedance parameters postulated adsorption on the mild steel specimens' surfaces of, which it going to the formation of protective coating layer. It also shows that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol corrosion inhibitors are effective in helping to reduce and slow down the corrosion process that occurs on mild steel surface in hydrochloric acid solution. Increase of corrosion inhibitor concentration provides a protective layer of mild steel. However, this protective layer becomes weak when the temperature of the solution increases.

Synthesis of L-2-amino-8-oxodecanoic acid: an amino acid component of apicidins

OpenAIRE

Linares de la Morena, María Lourdes; Agejas Chicharro, Francisco Javier; Alajarín Ferrández, Ramón; Vaquero López, Juan José; Álvarez-Builla Gómez, Julio

2001-01-01

The synthesis Of L-2-amino-8-oxodecanoic acid (Aoda) is described. This is a rare amino acid component of apicidins, a family of new cyclic tetrapeptides, inhibitors of histone deacetylase. Aoda was synthesised in seven steps from L-glutamic acid along with some derivatives. Universidad de Alcalá Fundación General de la Universidad de Alcalá FEDER

Encapsulation-Induced Stress Helps Saccharomyces cerevisiae Resist Convertible Lignocellulose Derived Inhibitors

Directory of Open Access Journals (Sweden)

Johan O. Westman

2012-09-01

Full Text Available The ability of macroencapsulated Saccharomyces cerevisiae CBS8066 to withstand readily and not readily in situ convertible lignocellulose-derived inhibitors was investigated in anaerobic batch cultivations. It was shown that encapsulation increased the tolerance against readily convertible furan aldehyde inhibitors and to dilute acid spruce hydrolysate, but not to organic acid inhibitors that cannot be metabolized anaerobically. Gene expression analysis showed that the protective effect arising from the encapsulation is evident also on the transcriptome level, as the expression of the stress-related genes YAP1, ATR1 and FLR1 was induced upon encapsulation. The transcript levels were increased due to encapsulation already in the medium without added inhibitors, indicating that the cells sensed low stress level arising from the encapsulation itself. We present a model, where the stress response is induced by nutrient limitation, that this helps the cells to cope with the increased stress added by a toxic medium, and that superficial cells in the capsules degrade convertible inhibitors, alleviating the inhibition for the cells deeper in the capsule.

Sucrose fatty esters from underutilized seed oil of Terminalia catappa as potential steel corrosion inhibitor in acidic medium

Directory of Open Access Journals (Sweden)

Adewale Adewuyi

2016-12-01

Full Text Available Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of Terminalia catappa and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium.

Reciprocal effects of 5-(tetradecyloxy)-2-furoic acid on fatty acid oxidation.

Science.gov (United States)

Otto, D A; Chatzidakis, C; Kasziba, E; Cook, G A

1985-10-01

Under certain incubation conditions 5-(tetradecyloxy)-2-furoic acid (TOFA) stimulated the oxidation of palmitate by hepatocytes, as observed by others. A decrease in malonyl-CoA concentration accompanied the stimulation of oxidation. Under other conditions, however, TOFA inhibited fatty acid oxidation. The observed effects of TOFA depended on the TOFA and fatty acid concentrations, the cell concentration, the time of TOFA addition relative to the addition of fatty acid, and the nutritional state of the animal (fed or starved). The data indicate that only under limited incubation conditions may TOFA be used as an inhibitor of fatty acid synthesis without inhibition of fatty acid oxidation. When rat liver mitochondria were preincubated with TOFA, ketogenesis from palmitate was slightly inhibited (up to 20%) at TOFA concentrations that were less than that of CoA, but the inhibition became almost complete (up to 90%) when TOFA was greater than or equal to the CoA concentration. TOFA had only slight or no inhibitory effects on the oxidation of palmitoyl-CoA, palmitoyl(-)carnitine, or butyrate. Since TOFA can be converted to TOFyl-CoA, the data suggest that the inhibition of fatty acid oxidation from palmitate results from the decreased availability of CoA for extramitochondrial activation of fatty acids. These data, along with previous data of others, indicate that inhibition of fatty acid oxidation by CoA sequestration is a common mechanism of a group of carboxylic acid inhibitors. A general caution is appropriate with regard to the interpretation of results when using TOFA in studies of fatty acid oxidation.

Discovery of a low-systemic-exposure DGAT-1 inhibitor with a picolinoylpyrrolidine-2-carboxylic acid moiety.

Science.gov (United States)

Yan, Jianwei; Wang, Gaihong; Dang, Xiangyu; Guo, Binbin; Chen, Wuhong; Wang, Ting; Zeng, Limin; Wang, Heyao; Hu, Youhong

2017-09-01

A series of diacylglycerol O-acyltransferase 1 (DGAT-1) inhibitors with a picolinoylpyrrolidine-2-carboxylic acid moiety were designed and synthesized. Of these compounds, compound 22 exhibited excellent DGAT-1-inhibitory activity (hDGAT-1 enzyme assay, 50% inhibitory concentration [IC 50 ]=3.5±0.9nM) and effectively reduced the intracellular triglyceride contents in 3T3-L1, HepG2 and Caco-2 cells. A preliminary study of the plasma and tissue distributions of compound 22 in mice revealed low plasma exposure and high concentrations in different segments of the intestine and liver, which may facilitate targeting DGAT-1. Furthermore, in an acute lipid challenge test, compound 22 showed a dose-dependent inhibitory effect on high-serum triglycerides in C57/KSJ mice induced by olive oil (1, 3, and 10mg/kg, i.g.). Copyright © 2017 Elsevier Ltd. All rights reserved.

Binding of the Inhibitor Protein IF1 to Bovine F1-ATPase

Science.gov (United States)

Bason, John V.; Runswick, Michael J.; Fearnley, Ian M.; Walker, John E.

2011-01-01

In the structure of bovine F1-ATPase inhibited with residues 1–60 of the bovine inhibitor protein IF1, the α-helical inhibitor interacts with five of the nine subunits of F1-ATPase. In order to understand the contributions of individual amino acid residues to this complex binding mode, N-terminal deletions and point mutations have been introduced, and the binding properties of each mutant inhibitor protein have been examined. The N-terminal region of IF1 destabilizes the interaction of the inhibitor with F1-ATPase and may assist in removing the inhibitor from its binding site when F1Fo-ATPase is making ATP. Binding energy is provided by hydrophobic interactions between residues in the long α-helix of IF1 and the C-terminal domains of the βDP-subunit and βTP-subunit and a salt bridge between residue E30 in the inhibitor and residue R408 in the C-terminal domain of the βDP-subunit. Several conserved charged amino acids in the long α-helix of IF1 are also required for establishing inhibitory activity, but in the final inhibited state, they are not in contact with F1-ATPase and occupy aqueous cavities in F1-ATPase. They probably participate in the pathway from the initial interaction of the inhibitor and the enzyme to the final inhibited complex observed in the structure, in which two molecules of ATP are hydrolysed and the rotor of the enzyme turns through two 120° steps. These findings contribute to the fundamental understanding of how the inhibitor functions and to the design of new inhibitors for the systematic analysis of the catalytic cycle of the enzyme. PMID:21192948

[Insect cholinesterases and irreversible inhibitors. Statistical treatment of the data].

Science.gov (United States)

Moralev, S N

2010-01-01

The data on sensitivity of cholinesterases (ChE) of different insects to reversible inhibitors, as well as the data on physico-chemical parameters of amino acids constituting their active centers, were treated by factor analysis and juxtaposed. It is shown that both these characteristics are related to taxonomical belonging of insects. It is revealed the "material substrate" of the factors determining inhibitor action specificity, which are specific sites in ChE active center.

Benzene-1,3-dicarboxylic acid 2,5-dimethylpyrrole derivatives as multiple inhibitors of bacterial Mur ligases (MurC-MurF).

Science.gov (United States)

Perdih, Andrej; Hrast, Martina; Barreteau, Hélène; Gobec, Stanislav; Wolber, Gerhard; Solmajer, Tom

2014-08-01

Enzymes catalyzing the biosynthesis of bacterial peptidoglycan represent traditionally a collection of highly selective targets for novel antibacterial drug design. Four members of the bacterial Mur ligase family-MurC, MurD, MurE and MurF-are involved in the intracellular steps of peptidoglycan biosynthesis, catalyzing the synthesis of the peptide moiety of the Park's nucleotide. In our previous virtual screening campaign, a chemical class of benzene-1,3-dicarboxylic acid 2,5-dimethylpyrrole derivatives exhibiting dual MurD/MurE inhibition properties was discovered. In the present study we further investigated this class of compounds by performing inhibition assays on all four Mur ligases (MurC-MurF). Furthermore, molecular dynamics (MD) simulation studies of one of the initially discovered compound 1 were performed to explore its geometry as well as its energetic behavior based on the Linear Interaction Energy (LIE) method. Further in silico virtual screening (VS) experiments based on the parent active compound 1 were conducted to optimize the discovered series. Selected hits were assayed against all Escherichia coli MurC-MurF enzymes in biochemical inhibition assays and molecules 10-14 containing benzene-1,3-dicarboxylic acid 2,5-dimethylpyrrole coupled with five member-ring rhodanine moiety were found to be multiple inhibitors of the whole MurC-MurF cascade of bacterial enzymes in the micromolar range. Steady-state kinetics studies suggested this class to act as competitive inhibitors of the MurD enzyme towards d-Glu. These compounds represent novel valuable starting point in the development of novel antibacterial agents. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nucleotide sequence of a cDNA coding for the barley seed protein CMa: an inhibitor of insect α-amylase

DEFF Research Database (Denmark)

Rasmussen, Søren Kjærsgård; Johansson, A.

1992-01-01

The primary structure of the insect alpha-amylase inhibitor CMa of barley seeds was deduced from a full-length cDNA clone pc43F6. Analysis of RNA from barley endosperm shows high levels 15 and 20 days after flowering. The cDNA predicts an amino acid sequence of 119 residues preceded by a signal...... peptide of 25 amino acids. Ala and Leu account for 55% of the signal peptide. CMa is 60-85% identical with alpha-amylase inhibitors of wheat, but shows less than 50% identity to trypsin inhibitors of barley and wheat. The 10 Cys residues are located in identical positions compared to the cereal inhibitor...

A new insight into resource recovery of excess sewage sludge: Feasibility of extracting mixed amino acids as an environment-friendly corrosion inhibitor for industrial pickling

Energy Technology Data Exchange (ETDEWEB)

Su, Wen; Tang, Bing, E-mail: renytang@163.com; Fu, Fenglian; Huang, Shaosong; Zhao, Shiyuan; Bin, Liying; Ding, Jiewei; Chen, Cuiqun

2014-08-30

Graphical abstract: - Highlights: • A value-added product was extracted from the municipal excess sludge. • The effective components contained in the product were mixed amino acids. • The product could provide a reliable protection to the steel from the acid medium. • A new insight into the resource recovery of excess sewage sludge was provided. - Abstract: The work mainly presented a laboratory-scale investigation on an effective process to extract a value-added product from municipal excess sludge. The functional groups in the hydrolysate were characterized with Fourier transform infrared spectrum, and the contained amino acids were measured by means of an automatic amino acid analyzer. The corrosion-inhibition characteristics of the hydrolysate were determined with weight-loss measurement, electrochemical polarization and scanning electron microscopy. Results indicated that the hydrolysate contained 15 kinds of amino acid, and their adsorption on the surface could effectively inhibit the corrosion reaction of the steel from the acid medium. Polarization curves indicated that the obtained hydrolysate was a mixed-type inhibitor, but mainly restricted metal dissolution on the anode. The adsorption accorded well with the Langmuir adsorption isotherm, involved an increase in entropy, and was a spontaneous, exothermic process.

A new insight into resource recovery of excess sewage sludge: Feasibility of extracting mixed amino acids as an environment-friendly corrosion inhibitor for industrial pickling

International Nuclear Information System (INIS)

Su, Wen; Tang, Bing; Fu, Fenglian; Huang, Shaosong; Zhao, Shiyuan; Bin, Liying; Ding, Jiewei; Chen, Cuiqun

2014-01-01

Graphical abstract: - Highlights: • A value-added product was extracted from the municipal excess sludge. • The effective components contained in the product were mixed amino acids. • The product could provide a reliable protection to the steel from the acid medium. • A new insight into the resource recovery of excess sewage sludge was provided. - Abstract: The work mainly presented a laboratory-scale investigation on an effective process to extract a value-added product from municipal excess sludge. The functional groups in the hydrolysate were characterized with Fourier transform infrared spectrum, and the contained amino acids were measured by means of an automatic amino acid analyzer. The corrosion-inhibition characteristics of the hydrolysate were determined with weight-loss measurement, electrochemical polarization and scanning electron microscopy. Results indicated that the hydrolysate contained 15 kinds of amino acid, and their adsorption on the surface could effectively inhibit the corrosion reaction of the steel from the acid medium. Polarization curves indicated that the obtained hydrolysate was a mixed-type inhibitor, but mainly restricted metal dissolution on the anode. The adsorption accorded well with the Langmuir adsorption isotherm, involved an increase in entropy, and was a spontaneous, exothermic process

Investigations and design of pyridine-2-carboxylic acid thiazol-2-ylamide analogs as methionine aminopeptidase inhibitors using 3D-QSAR and molecular docking

DEFF Research Database (Denmark)

Hauser, Alexander Sebastian

2014-01-01

complexes, four new pyridine-2-carboxylic acid thiazol-2-ylamide analogs were designed. These analogs exhibit significantly better predicted activity than the reported molecules. The present work has implications for the development of novel antibiotics as potent MetAP inhibitors.......Methionine amino peptidases (MetAPs) are metalloproteases that remove co-translational N-terminal methionine from nascent polypeptide chains. Due to their essential role in protein synthesis, MetAPs are considered as potential targets for antibacterial drugs. In the present work, three...

Citral derived amides as potent bacterial NorA efflux pump inhibitors

DEFF Research Database (Denmark)

Thota, Niranjan; Koul, Surrinder; Reddy, Mallepally V

2008-01-01

Monoterpene citral and citronellal have been used as starting material for the preparation of 5,9-dimethyl-deca-2,4,8-trienoic acid amides and 9-formyl-5-methyl-deca-2,4,8-trienoic acid amides. The amides on bioevaluation as efflux pump inhibitors (EPIs) against Staphylococcus aureus 1199 and NorA...

Inhibitor efficiency in long-time protection of steel tanks for the chemical surface preparation against local corrosion by process solutions containing hydrochloric acid; Inhibitorwirksamkeit beim Langzeitschutz von Stahlbehaeltern fuer die chemische Oberflaechenvorbereitung gegen oertliche Korrosion durch salzsaeurehaltige Prozessloesungen

Energy Technology Data Exchange (ETDEWEB)

Stieglitz, U.; Schulz, W.D. [Institut fuer Korrosionsschutz Dresden GmbH, Gostritzer Str. 61-63, D-01217 Dresden (Germany)

2004-02-01

The efficiency of prevailing acid inhibitors is examined by age hardening heavy tank-steel plates in technically usual hot-galvanizing solutions for 1000 hours. With acid inhibitors local corrosion emerged as shallow pit formation first and foremost in hydrochlorid acid pickles (20 g/l HCl) at ambient temperature as well as in cleaners containing hydrochloric acid (10-30 g/l HCl) at 40 C when other conditions also applied. Above all, local corrosion was produced if the inhibitor concentration became too low (0.2 g/l) in connection with a minimum hydrochloric acid concentration (10-30 g/l). However, oxidizing agents like iron(III)-ions (5-10 g/l), atmospheric oxygen and free chlorine (100-1000 mg/l) lead to local corrosion, too. Local corrosion did not emerge in rinse baths (2-10 g/l HCl) and fluxing material solutions of zinc chloride and ammonium chloride (pH value: 2.0-5.5). Here uniform corrosion developed. Acid inhibitors turned out to be very effective against uniform corrosion in the examined long-time period (inhibiting values up to 99%). (Abstract Copyright [2004], Wiley Periodicals, Inc.) [German] Die Wirksamkeit handelsueblicher Saeureinhibitoren wird durch eine Auslagerung von Grobblechen aus Behaelterstahl ueber 1000 Stunden in technisch gebraeuchlichen Loesungen der Feuerverzinkung untersucht. Oertliche Korrosion ist als Muldenkorrosion in Gegenwart von Saeureinhibitoren vor allem in Salzsaeurebeizen (20 g/l HCl) bei Raumtemperatur und in salzsaeurehaltigen Reinigern (10-30 g/l HCl) bei 40 C aufgetreten, wenn Zusatzbedingungen erfuellt sind. Oertliche Korrosion wird vorwiegend durch eine Unterschreitung der Inhibitorkonzentration (0,2 g/l) in Verbindung mit einer minimalen Salzsaeurekonzentration (10-30 g/l) ausgeloest. Aber auch Oxidationsmittel wie Eisen(III)-Ionen (5-10 g/l), Luftsauerstoff und freies Chlor (100-1000 mg/l) fuehren zu oertlicher Korrosion. In Spuelbaedern (2-10 g/l HCl) und Flussmittelloesungen aus Zinkchlorid und Ammoniumchlorid (p

Synthesis of 1- and 3-11C-labelled L-lactic acid using multi-enzyme catalysis

International Nuclear Information System (INIS)

Bjurling, P.; Laangstroem, B.

1990-01-01

The synthesis of 1- and 3- 11 C-labelled L-lactic acid from the corresponding racemic 1- or 3- 11 C-labelled alanine using a multi-enzymatic reaction route, is presented. DL-[1- 11 C]Alanine was synthesised by reacting sodium 1-hydroxy-ethyl sulfite with hydrogen [ 11 C]cyanide, obtained from [ 11 C]carbon dioxide, and ammonia followed by acid hydrolysis. DL-[3- 11 C]-Alanine was synthesised by a methylation of a glycine derivative, N-(diphenylmethylene)-glycine tert-butyl ester, with [ 11 C]methyl iodide, obtained from [ 11 C]carbon dioxide, and subsequent hydrolysis. The racemic 1- or 3- 11 C-labelled alanine was then converted to pyruvic acid, by D-amino acid oxidase/catalase and glutamic-pyruvic transaminase, which was directly reduced to L-lactic acid by L-lactic dehydrogenase in a one-pot procedure. The total synthesis time was 40 minutes, counted from release of [ 11 C]carbon dioxide. The decay corrected radiochemical yields were ca. 80% for L-[1- 11 C]lactic acid, based on hydrogen cyanide, and ca. 60% for L-[3- 11 C]lactic acid, based on carbon dioxide. The radiochemical purities were higher than 99% analysed by HPLC. (author)

Changes of ammonia, urea contents and transaminase activity in the body during aerial exposure and ammonia loading in Chinese loach Paramisgurnus dabryanus.

Science.gov (United States)

Zhang, Yun-Long; Zhang, Hai-Long; Wang, Ling-Yu; Gu, Bei-Yi; Fan, Qi-Xue

2017-04-01

The Paramisgurnus dabryanus was exposed to 30 mmol L -1 NH 4 Cl solution and air to assessing the change of body ammonia and urea contents and the activities of alanine aminotransferase (ALT) and aspartate transaminase (AST). After 48 h of ammonia exposure, ammonia concentration in the plasma, brain, liver and muscle were 3.3-fold, 5.6-fold, 3.5-fold and 4.2-fold, respectively, those of the control values. Plasma, brain, liver and muscle ammonia concentrations increased to 2.2-fold, 3.3-fold, 2.5-fold and 2.9-fold, respectively, those of control values in response to 48 h of aerial exposure. Within the given treatment (ammonia or aerial exposure), there was no change in plasma, brain and liver urea concentrations between exposure durations. The plasma ALT activity was significantly affected by exposure time during aerial exposure, while the liver ALT activity was not affected by ammonia or aerial exposure. Exposure to NH 4 Cl or air had no effect on either plasma or liver AST activity. Our results suggested that P. dabryanus could accumulate quite high level of internal ammonia because of the high ammonia tolerance in its cells and tissues, and NH 3 volatilization would be a possible ammonia detoxification strategy in P. dabryanus. Urea synthesis was not an effective mechanism to deal with environmental or internal ammonia problem. The significant increase of ALT activity in plasma during aerial exposure, indicating that alanine synthesis through certain amino acid catabolism may be subsistent in P. dabryanus.

Chiral amine synthesis using ω-transaminases: an amine donor that displaces equilibria and enables high-throughput screening.

Science.gov (United States)

Green, Anthony P; Turner, Nicholas J; O'Reilly, Elaine

2014-09-26

The widespread application of ω-transaminases as biocatalysts for chiral amine synthesis has been hampered by fundamental challenges, including unfavorable equilibrium positions and product inhibition. Herein, an efficient process that allows reactions to proceed in high conversion in the absence of by-product removal using only one equivalent of a diamine donor (ortho-xylylenediamine) is reported. This operationally simple method is compatible with the most widely used (R)- and (S)-selective ω-TAs and is particularly suitable for the conversion of substrates with unfavorable equilibrium positions (e.g., 1-indanone). Significantly, spontaneous polymerization of the isoindole by-product generates colored derivatives, providing a high-throughput screening platform to identify desired ω-TA activity. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Shortcomings of the first-generation proton pump inhibitors

NARCIS (Netherlands)

Tytgat, G. N.

2001-01-01

Proton pump inhibitors (PPIs) are widely prescribed for the treatment of gastro-oesophageal reflux disease (GORD) as well as gastric and duodenal ulcers, and these agents are now considered the drugs of choice for managing such acid-related disorders. Despite their well-documented efficacy and

Structure-activity relationships of 3-O-β-chacotriosyl oleanic acid derivatives as entry inhibitors for highly pathogenic H5N1 influenza virus.

Science.gov (United States)

Li, Sumei; Jia, Xiuhua; Shen, Xintian; Wei, Zhuwen; Jiang, Zhiyan; Liao, Yixian; Guo, Yiming; Zheng, Xiaojun; Zhong, Guohua; Song, Gaopeng

2017-08-15

Highly pathogenic H5N1 virus (H5N1) entry is a key target for the development of novel anti-influenza agents with new mechanisms of action. In our continuing efforts to identify novel potential anti-H5N1 entry inhibitors, a series of 3-O-β-chacotriosyl oleanolic acid analogs have been designed, synthesized and evaluated as H5N1 entry inhibitors based on two small molecule inhibitors 1 and 2 previously discovered by us. The anti-H5N1 entry activities were determined based on HA/HIV and VSVG/HIV entry assays. Compound 15 displayed the most promising anti-H5N1 entry activities with average IC 50 values of 4.05μM and good selective index (22.9). Detailed structure-activity relationships (SARs) studies suggested that either the introduction of an additional oxo group to position 11 at OA or alteration of the C-3 configuration of OA from 3β- to 3α-forms can significantly enhance the selective index while maintaining their antiviral activities in vitro. Molecular simulation analysis confirmed that the compounds exert their inhibitory activity through binding tightly to hemagglutinin (HA2) protein near the fusion peptide and prevent virus entry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multifunctional Cinnamic Acid Derivatives

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Aikaterini Peperidou

2017-07-01

Full Text Available Our research to discover potential new multitarget agents led to the synthesis of 10 novel derivatives of cinnamic acids and propranolol, atenolol, 1-adamantanol, naphth-1-ol, and (benzylamino ethan-1-ol. The synthesized molecules were evaluated as trypsin, lipoxygenase and lipid peroxidation inhibitors and for their cytotoxicity. Compound 2b derived from phenoxyphenyl cinnamic acid and propranolol showed the highest lipoxygenase (LOX inhibition (IC50 = 6 μΜ and antiproteolytic activity (IC50 = 0.425 μΜ. The conjugate 1a of simple cinnamic acid with propranolol showed the higher antiproteolytic activity (IC50 = 0.315 μΜ and good LOX inhibitory activity (IC50 = 66 μΜ. Compounds 3a and 3b, derived from methoxylated caffeic acid present a promising combination of in vitro inhibitory and antioxidative activities. The S isomer of 2b also presented an interesting multitarget biological profile in vitro. Molecular docking studies point to the fact that the theoretical results for LOX-inhibitor binding are identical to those from preliminary in vitro study.

The discovery of novel tartrate-based TNF-[alpha] converting enzyme (TACE) inhibitors

Energy Technology Data Exchange (ETDEWEB)

Rosner, Kristin E.; Guo, Zhuyan; Orth, Peter; Shipps, Jr., Gerald W.; Belanger, David B.; Chan, Tin Yau; Curran, Patrick J.; Dai, Chaoyang; Deng, Yongqi; Girijavallabhan, Vinay M.; Hong, Liwu; Lavey, Brian J.; Lee, Joe F.; Li, Dansu; Liu, Zhidan; Popovici-Muller, Janeta; Ting, Pauline C.; Vaccaro, Henry; Wang, Li; Wang, Tong; Yu, W.; Zhou, G.; Niu, X.; Sun, J.; Kozlowski, J.A.; Lundell, D.J.; Madison, V.; McKittrick, B.; Piwinski, J.J.; Shih, N.Y.; Siddiqui, M. Arshad; Strickland, Corey O. (SPRI)

2010-09-17

A novel series of TNF-{alpha} convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.

Effect of Free Fatty Acids Supplementation on Digestibility, Nutritive Value and Rumen Fermentation in Local Sheep

International Nuclear Information System (INIS)

El-Foly, H.A.; Mohamed, A.K.; Mustafa, M.M.M.

2014-01-01

Twelve mature local sheep, with a mean body weight of 49.2±3 kg were randomly distributed into three digestibility trail groups to evaluate the effects of inclusion some oils industry by-products, soft fatty acid (SFA) and hard fatty acid (HFA) on dry matter intake, digestibility coefficients, nutritive values, nitrogen and energy utilization and some rumen and blood parameters. The experimental diets were basal diet un-supplemented (control) or supplemented 3% SFA (T1) and 3% HFA (T2). The results showed that non-significant differences in total dry matter intake and water consumption among the tested diets were observed.The digestibility of dry matter (DM), organic matter (OM) and nitrogen free extract (NFE) were significantly increased (P<0.05) by addition of SFA while digestibility of crude protein (CP) and ether extract (EE) was significantly increased (P<0.05) by addition of HFA as compared with control. However, digestibility of crude fiber (CF) was significantly decreased (P<0.05) in T2 as compared with control and T1. Fatty acids supplementation significantly increased (P<0.05) the nutritive values such as TDN, SV and DCP as compared with control.The nitrogen utilization was significantly improved (P<0.05) by the addition of both additives. The values of total volatile fatty acid concentrations (TVFA) and pH values after feeding were significantly increased (P<0.05) with HFA supplementation as compared with the values of other groups. However, the rumina l ammonia-N concentrations after feeding significantly decreased (P<0.05) with fatty acids supplementation as compared with control. The results of digestible and metabolizable energy showed non-significant differences between the tested groups. Blood serum urea, albumen, cholesterol, triglycerides and phosphorus values were significantly increased (P<0.05) with HFA as compared with the values of other groups.The mean values of serum alanine transaminase (ALT), aspartate transaminase (AST

Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

Directory of Open Access Journals (Sweden)

Mohammad Mobin

2012-12-01

Full Text Available Gemini surfactants, butanediyl 1,4-bis(dimethyl cetylammonium bromide, pentanediyl 1,5 - bis (dimethyl cetylammonium bromide and hexanediyl 1,6 - bis (dimethyl cetylammonium bromide from Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide series were synthesized in laboratory and were characterized by using Nuclear Magnetic Resonance (NMR spectroscopy. The surfactants were tested as corrosion inhibitors for mild steel in 20% formic acid. The influence of surfactants on mild steel corrosion inhibition was investigated by measuring the corrosion rate of mild steel in their absence and presence by weight loss measurements, solvent analysis of iron ions into the test solution and potentiodynamic polarization measurements. The surface morphology of the corroded steel samples in presence and absence of surfactants was evaluated by using Scanning Electron Microscopy (SEM. The synthesized gemini surfactants performed as excellent corrosion inhibitor, the inhibition efficiency (IE being in the range of 76.66-97.41%. The IE of surfactants is slightly affected by the spacer length. The IE increased with increase in surfactant concentration and temperature. The adsorption of gemini surfactants on the steel surface was found to obey Langmuir adsorption isotherm. The results of the potentiodynamic polarization studies are consistent with the results of weight loss studies.

Development of new corrosion inhibitor tested on mild steel supported by electrochemical study

Directory of Open Access Journals (Sweden)

Hussein Jwad Habeeb

2018-03-01

Full Text Available Mild steel is a metal which is commonly used in industrials and manufacturing of equipment for most industries round the world. It is cheaper cost compared with the other metals and its durable, hard and easy-to-wear physical properties make it a major choice in the manufacture of equipment parts. The main problem through the uses of mild steel in industry is its resistance against corrosion, especially in acidic solutions. This case led to raise the cost of maintenance of equipment that used mild steel and as a result increased costs for the company. Organic corrosive inhibitors that also act as green chemicals, 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol have been synthesized. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution (HCl using electrochemical measurements test includes PD (Potentiodynamic, EIS (Electrochemical impedance spectroscopy, OCP (Open circuit potential and EFM (electrochemical frequency modulation. The obtained results indicate that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol acts as a good corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the impedance parameters postulated adsorption on the mild steel specimens' surfaces of, which it going to the formation of protective coating layer. It also shows that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol corrosion inhibitors are effective in helping to reduce and slow down the corrosion process that occurs on mild steel surface in hydrochloric acid solution. Increase of corrosion inhibitor concentration provides a protective layer of mild steel. However, this protective layer becomes weak when the temperature of the solution increases. Keywords: Hydroxybenzylideneaminomethy, Potentiodynamic, Electrochemical frequency modulation, Impedance

Synthesis, characterization and corrosion inhibition properties of benzamide-2-chloro-4-nitrobenzoic acid and anthranilic acid-2-chloro-4-nitrobenzoic acid for mild steel corrosion in acidic medium

Science.gov (United States)

Pandey, Archana; Verma, Chandrabhan; Singh, B.; Ebenso, Eno E.

2018-03-01

The present study deals with the synthesis of two new compounds namely, benzamide - 2-chloro-4-nitrobenzoic acid (BENCNBA) and anthranilic acid-2-chloro-4-nitrobenzoic acid (AACNBA) using solid phase reactions. The phase diagram studies revealed that formation of the investigated compounds occurs in 1:1 molar ratio. The synthesized compounds were characterized using several spectral techniques such as FT-IR, 1H and 13C NMR, UV-Vis, powder X-ray diffraction (PXRD). Single crystal XRD (SCXRD) study showed that both BENCNBA and AACNBA compounds crystallize in triclinic crystal system with P-1 space group. Further, the presence of intermolecular hydrogen bonding between the constituent components was also supported by single crystal X-ray diffraction (SCXRD) method. Heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions have also been computed using the enthalpy of fusion values derived from differential scanning calorimeter (DSC) study. The inhibition effect of BENCNBA and AACNBA on the mild steel corrosion in hydrochloric acid solution was tested using electrochemical methods. Electrochemical impedance spectroscopy (EIS) study revealed that both BENCNBA and AACNBA behaved as interface corrosion inhibitors and showed maximum inhibition efficiencies of 95.71% and 96.42%, respectively at 400 ppm (1.23 × 10-3 M) concentration. Potentiodynamic polarization (PDP) measurements suggested that BENCNBA and AACNBA acted as mixed type corrosion inhibitors. EIS and PDP results showed that BENCNBA and AACNBA act as efficient corrosion inhibitors for mild steel and their inhibition efficiencies enhances on increasing their concentrations.

Metabolic flux rearrangement in the amino acid metabolism reduces ammonia stress in the α1-antitrypsin producing human AGE1.HN cell line.

Science.gov (United States)

Priesnitz, Christian; Niklas, Jens; Rose, Thomas; Sandig, Volker; Heinzle, Elmar

2012-03-01

This study focused on metabolic changes in the neuronal human cell line AGE1.HN upon increased ammonia stress. Batch cultivations of α(1)-antitrypsin (A1AT) producing AGE1.HN cells were carried out in media with initial ammonia concentrations ranging from 0mM to 5mM. Growth, A1AT production, metabolite dynamics and finally metabolic fluxes calculated by metabolite balancing were compared. Growth and A1AT production decreased with increasing ammonia concentration. The maximum A1AT concentration decreased from 0.63g/l to 0.51g/l. Central energy metabolism remained relatively unaffected exhibiting only slightly increased glycolytic flux at high initial ammonia concentration in the medium. However, the amino acid metabolism was significantly changed. Fluxes through transaminases involved in amino acid degradation were reduced concurrently with a reduced uptake of amino acids. On the other hand fluxes through transaminases working in the direction of amino acid synthesis, i.e., alanine and phosphoserine, were increased leading to increased storage of excess nitrogen in extracellular alanine and serine. Glutamate dehydrogenase flux was reversed increasingly fixing free ammonia with increasing ammonia concentration. Urea production additionally observed was associated with arginine uptake by the cells and did not increase at high ammonia stress. It was therefore not used as nitrogen sink to remove excess ammonia. The results indicate that the AGE1.HN cell line can adapt to ammonia concentrations usually present during the cultivation process to a large extent by changing metabolism but with slightly reduced A1AT production and growth. Copyright © 2012 Elsevier Inc. All rights reserved.

Sodium-Glucose Linked Transporter-2 Inhibitors in Chronic Kidney Disease

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L. Zanoli

2015-01-01

Full Text Available SGLT2 inhibitors are new antihyperglycaemic agents whose ability to lower glucose is directly proportional to GFR. Therefore, in chronic kidney disease (CKD the blood glucose lowering effect is reduced. Unlike many current therapies, the mechanism of action of SGLT2 inhibitors is independent of insulin action or beta-cell function. In addition, the mechanism of action of SGLT2 inhibitors is complementary and not alternative to other antidiabetic agents. SGLT2 inhibitors could be potentially effective in attenuating renal hyperfiltration and, consequently, the progression of CKD. Moreover, the reductions in intraglomerular pressure, systemic blood pressure, and uric acid levels induced by SGLT inhibition may potentially be of benefit in CKD subjects without diabetes. However, at present, only few clinical studies were designed to evaluate the effects of SGLT2 inhibitors in CKD. Consequently, safety and potential efficacy beyond blood glucose lowering should be better clarified in CKD. In this paper we provide an updated review of the use of SGLT2 inhibitors in clinical practice, with particular attention on subjects with CKD.

A dual-specificity isoform of the protein kinase inhibitor PKI produced by alternate gene splicing.

Science.gov (United States)

Kumar, Priyadarsini; Walsh, Donal A

2002-03-15

We have previously shown that the protein kinase inhibitor beta (PKIbeta) form of the cAMP-dependent protein kinase inhibitor exists in multiple isoforms, some of which are specific inhibitors of the cAMP-dependent protein kinase, whereas others also inhibit the cGMP-dependent enzyme [Kumar, Van Patten and Walsh (1997), J. Biol. Chem. 272, 20011-20020]. We have now demonstrated that the switch from a cAMP-dependent protein kinase (PKA)-specific inhibitor to one with dual specificity arises as a consequence of alternate gene splicing. We have confirmed using bacterially produced pure protein that a single inhibitor species has dual specificity for both PKA and cGMP-dependent protein kinase (PKG), inhibiting each with very high and closely similar inhibitory potencies. The gene splicing converted a protein with 70 amino acids into one of 109 amino acids, and did not change the inhibitory potency to PKA, but changed it from a protein that had no detectable PKG inhibitory activity to one that now inhibited PKG in the nanomolar range.

Corrosion Inhibition of Aluminium in Acid Media By Citrullus Colocynthis Extract

OpenAIRE

Chauhan, Rajkiran; Garg, Urvija; Tak, R. K.

2011-01-01

Inhibition of corrosion of aluminium in acid solution by methanol extract of Citrullus colocynthis plant has been studied using mass loss and thermometric measurements. It has been found that the plant extract act as a good corrosion inhibitor for aluminium in all concentrations of sulphuric and hydrochloric acid solution. The inhibition action depends on the concentration of acid and inhibitor. Results for mass loss and thermometric measurement indicate that inhibition efficiency increase wi...

Designing inhibitors of cytochrome c/cardiolipin peroxidase complexes: mitochondria-targeted imidazole-substituted fatty acids.

Science.gov (United States)

Jiang, Jianfei; Bakan, Ahmet; Kapralov, Alexandr A; Silva, K Ishara; Huang, Zhentai; Amoscato, Andrew A; Peterson, James; Garapati, Venkata Krishna; Saxena, Sunil; Bayir, Hülya; Atkinson, Jeffrey; Bahar, Ivet; Kagan, Valerian E

2014-06-01

Mitochondria have emerged as the major regulatory platform responsible for the coordination of numerous metabolic reactions as well as cell death processes, whereby the execution of intrinsic apoptosis includes the production of reactive oxygen species fueling oxidation of cardiolipin (CL) catalyzed by cytochrome (Cyt) c. As this oxidation occurs within the peroxidase complex of Cyt c with CL, the latter represents a promising target for the discovery and design of drugs with antiapoptotic mechanisms of action. In this work, we designed and synthesized a new group of mitochondria-targeted imidazole-substituted analogs of stearic acid TPP-n-ISAs with various positions of the attached imidazole group on the fatty acid (n = 6, 8, 10, 13, and 14). By using a combination of absorption spectroscopy and EPR protocols (continuous wave electron paramagnetic resonance and electron spin echo envelope modulation) we demonstrated that TPP-n-ISAs indeed were able to potently suppress CL-induced structural rearrangements in Cyt c, paving the way to its peroxidase competence. TPP-n-ISA analogs preserved the low-spin hexa-coordinated heme-iron state in Cyt c/CL complexes whereby TPP-6-ISA displayed a significantly more effective preservation pattern than TPP-14-ISA. Elucidation of these intermolecular stabilization mechanisms of Cyt c identified TPP-6-ISA as an effective inhibitor of the peroxidase function of Cyt c/CL complexes with a significant antiapoptotic potential realized in mouse embryonic cells exposed to ionizing irradiation. These experimental findings were detailed and supported by all-atom molecular dynamics simulations. Based on the experimental data and computation predictions, we identified TPP-6-ISA as a candidate drug with optimized antiapoptotic potency. Copyright © 2014 Elsevier Inc. All rights reserved.

A thermostable serralysin inhibitor from marine bacterium Flavobacterium sp. YS-80-122

Science.gov (United States)

Liang, Pengjuan; Li, Shangyong; Wang, Kun; Wang, Fang; Xing, Mengxin; Hao, Jianhua; Sun, Mi

2018-03-01

Serralysin inhibitors have been proposed as potent drugs against many diseases and may help to prevent further development of antibiotic-resistant pathogenic bacteria. In this study, a novel serralysin inhibitor gene, lupI, was cloned from the marine bacterium Flavobacterium sp. YS-80-122 and expressed in Escherichia coli. The deduced serralysin inhibitor, LupI, shows <40% amino acid identity to other reported serralysin inhibitors. Multiple sequence alignment and phylogenetic analysis of LupI with other serralysin inhibitors indicated that LupI was a novel type of serralysin inhibitor. The inhibitory constant for LupI towards its target metalloprotease was 0.64 μmol/L. LupI was thermostable at high temperature, in which 35.6%-90.7% of its inhibitory activity was recovered after treatment at 100°C for 1-60 min followed by incubation at 0°C. This novel inhibitor may represent a candidate drug for the treatment of serralysin-related infections.

Substrate and inhibitor specificity of kynurenine monooxygenase from Cytophaga hutchinsonii.

Science.gov (United States)

Phillips, Robert S; Anderson, Andrew D; Gentry, Harvey G; Güner, Osman F; Bowen, J Phillip

2017-04-15

Kynurenine monooxygenase (KMO) is a potential drug target for treatment of neurodegenerative disorders such as Huntington's and Alzheimer's diseases. We have evaluated substituted kynurenines as substrates or inhibitors of KMO from Cytophaga hutchinsonii. Kynurenines substituted with a halogen at the 5-position are excellent substrates, with values of k cat and k cat /K m comparable to or higher than kynurenine. However, kynurenines substituted in the 3-position are competitive inhibitors, with K I values lower than the K m for kynurenine. Bromination also enhances inhibition, and 3,5-dibromokynurenine is a potent competitive inhibitor with a K I value of 1.5μM. A pharmacophore model of KMO was developed, and predicted that 3,4-dichlorohippuric acid would be an inhibitor. The K I for this compound was found to be 34μM, thus validating the pharmacophore model. We are using these results and our model to design more potent inhibitors of KMO. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proton pump inhibitor-refractory gastroesophageal reflux disease: challenges and solutions

Science.gov (United States)

Mermelstein, Joseph; Chait Mermelstein, Alanna; Chait, Maxwell M

2018-01-01

A significant percentage of patients with gastroesophageal reflux disease (GERD) will not respond to proton pump inhibitor (PPI) therapy. The causes of PPI-refractory GERD are numerous and diverse, and include adherence, persistent acid, functional disorders, nonacid reflux, and PPI bioavailability. The evaluation should start with a symptom assessment and may progress to imaging, endoscopy, and monitoring of esophageal pH, impedance, and bilirubin. There are a variety of pharmacologic and procedural interventions that should be selected based on the underlying mechanism of PPI failure. Pharmacologic treatments can include antacids, prokinetics, alginates, bile acid binders, reflux inhibitors, and antidepressants. Procedural options include laparoscopic fundoplication and LINX as well as endoscopic procedures, such as transoral incisionless fundoplication and Stretta. Several alternative and complementary treatments of possible benefit also exist. PMID:29606884

Ribavirin plus interferon versus interferon for chronic hepatitis C

DEFF Research Database (Denmark)

Brok, J; Gluud, L L; Gluud, C

2005-01-01

Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades and most patients are diagnosed based on the presence of hepatitis C virus ribonucleic acid and elevated transaminases.......Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades and most patients are diagnosed based on the presence of hepatitis C virus ribonucleic acid and elevated transaminases....

Discovery of a new mitochondria permeability transition pore (mPTP) inhibitor based on gallic acid.

Science.gov (United States)

Teixeira, José; Oliveira, Catarina; Cagide, Fernando; Amorim, Ricardo; Garrido, Jorge; Borges, Fernanda; Oliveira, Paulo J

2018-12-01

Pharmacological interventions targeting mitochondria present several barriers for a complete efficacy. Therefore, a new mitochondriotropic antioxidant (AntiOxBEN 3 ) based on the dietary antioxidant gallic acid was developed. AntiOxBEN 3 accumulated several thousand-fold inside isolated rat liver mitochondria, without causing disruption of the oxidative phosphorylation apparatus, as seen by the unchanged respiratory control ratio, phosphorylation efficiency, and transmembrane electric potential. AntiOxBEN 3 showed also limited toxicity on human hepatocarcinoma cells. Moreover, AntiOxBEN 3 presented robust iron-chelation and antioxidant properties in both isolated liver mitochondria and cultured rat and human cell lines. Along with its low toxicity profile and high antioxidant activity, AntiOxBEN 3 strongly inhibited the calcium-dependent mitochondrial permeability transition pore (mPTP) opening. From our data, AntiOxBEN 3 can be considered as a lead compound for the development of a new class of mPTP inhibitors and be used as mPTP de-sensitiser for basic research or clinical applications or emerge as a therapeutic application in mitochondria dysfunction-related disorders.