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Sample records for acid amide hydrolase

  1. Sulfonyl fluoride inhibitors of fatty acid amide hydrolase.

    Alapafuja, Shakiru O; Nikas, Spyros P; Bharathan, Indu T; Shukla, Vidyanand G; Nasr, Mahmoud L; Bowman, Anna L; Zvonok, Nikolai; Li, Jing; Shi, Xiaomeng; Engen, John R; Makriyannis, Alexandros

    2012-11-26

    Sulfonyl fluorides are known to inhibit esterases. Early work from our laboratory has identified hexadecyl sulfonylfluoride (AM374) as a potent in vitro and in vivo inhibitor of fatty acid amide hydrolase (FAAH). We now report on later generation sulfonyl fluoride analogs that exhibit potent and selective inhibition of FAAH. Using recombinant rat and human FAAH, we show that 5-(4-hydroxyphenyl)pentanesulfonyl fluoride (AM3506) has similar inhibitory activity for both the rat and the human enzyme, while rapid dilution assays and mass spectrometry analysis suggest that the compound is a covalent modifier for FAAH and inhibits its action in an irreversible manner. Our SAR results are highlighted by molecular docking of key analogs. PMID:23083016

  2. Defects in fatty acid amide hydrolase 2 in a male with neurologic and psychiatric symptoms

    Sirrs, Sandra; van Karnebeek, Clara DM; Peng, Xiaoxue; Shyr, Casper; Tarailo-Graovac, Maja; Mandal, Rupasri; Testa, Daniel; Dubin, Devin; Carbonetti, Gregory; Glynn, Steven E.; Sayson, Bryan; Robinson, Wendy P.; Han, Beomsoo; Wishart, David; Ross, Colin J

    2015-01-01

    Background Fatty acid amide hydrolase 2 (FAAH2) is a hydrolase that mediates the degradation of endocannabinoids in man. Alterations in the endocannabinoid system are associated with a wide variety of neurologic and psychiatric conditions, but the phenotype and biochemical characterization of patients with genetic defects of FAAH2 activity have not previously been described. We report a male with autistic features with an onset before the age of 2 years who subsequently developed additional f...

  3. Identification of N-acylethanolamines in Dictyostelium discoideum and confirmation of their hydrolysis by fatty acid amide hydrolase[S

    Hayes, Alexander C.; Stupak, Jacek; Li, Jianjun; Cox, Andrew D.

    2013-01-01

    N-acylethanolamines (NAEs) are endogenous lipid-based signaling molecules best known for their role in the endocannabinoid system in mammals, but they are also known to play roles in signaling pathways in plants. The regulation of NAEs in vivo is partly accomplished by the enzyme fatty acid amide hydrolase (FAAH), which hydrolyses NAEs to ethanolamine and their corresponding fatty acid. Inhibition of FAAH has been shown to increase the levels of NAEs in vivo and to produce desirable phenotype...

  4. Phenotypic assessment of THC discriminative stimulus properties in fatty acid amide hydrolase knockout and wildtype mice

    Walentiny, D. Matthew; Vann, Robert E.; Wiley, Jenny L.

    2015-01-01

    A number of studies have examined the ability of the endogenous cannabinoid anandamide to elicit Δ9 -tetrahydrocannabinol (THC)-like subjective effects, as modeled through the THC discrimination paradigm. In the present study, we compared transgenic mice lacking fatty acid amide hydrolase (FAAH), the enzyme primarily responsible for anandamide catabolism, to wildtype counterparts in a THC discrimination procedure. THC (5.6 mg/kg) served as a discriminative stimulus in both genotypes, with sim...

  5. Hemodynamic profile, responsiveness to anandamide, and baroreflex sensitivity of mice lacking fatty acid amide hydrolase

    Pacher, Pál; Bátkai, Sándor; Osei-Hyiaman, Douglas; Offertáler, László; Liu, Jie; Harvey-White, Judy; Brassai, Attila; Járai, Zoltán; Cravatt, Benjamin F.; Kunos, George

    2005-01-01

    The endocannabinoid anandamide exerts neurobehavioral, cardiovascular, and immune-regulatory effects through cannabinoid receptors (CB). Fatty acid amide hydrolase (FAAH) is an enzyme responsible for the in vivo degradation of anandamide. Recent experimental studies have suggested that targeting the endocannabinergic system by FAAH inhibitors is a promising novel approach for the treatment of anxiety, inflammation, and hypertension. In this study, we compared the cardiac performance of FAAH k...

  6. The role of fatty acid amide hydrolase inhibition in nicotine reward and dependence

    Muldoon, Pretal P.; Lichtman, Aron H.; Parsons, Loren H.; Damaj, M Imad

    2012-01-01

    The endogenous cannabinoid anandamide (AEA) exerts the majority of its effects at CB1 and CB2 receptors and is degraded by fatty acid amide hydrolase (FAAH). FAAH KO mice and animals treated with FAAH inhibitors are impaired in their ability to hydrolyze AEA and other non-cannabinoid lipid signaling molecules, such as oleoylethanolamide (OEA) and palmitoylethanolamide (PEA). AEA and these other substrates activate non- cannabinoid receptor systems, including TRPV1 and PPAR-α receptors. In thi...

  7. Cellular viability effects of fatty acid amide hydrolase inhibition on cerebellar neurons

    Lueneberg Kathia; Domínguez Guadalupe; Arias-Carrión Oscar; Palomero-Rivero Marcela; Millán-Aldaco Diana; Morán. Julio; Drucker-Colín René; Murillo-Rodríguez Eric

    2011-01-01

    Abstract The endocannabinoid anandamide (ANA) participates in the control of cell death inducing the formation of apoptotic bodies and DNA fragmentation. The aim of this study was to evaluate whether the ANA degrading enzyme, the fatty acid amide hydrolase (FAAH), would induce cellular death. Experiments were performed in cerebellar granule neurons cultured with the FAAH inhibitor, URB597 (25, 50 or 100 nM) as well as endogenous lipids such as oleoylethanolamide (OEA) or palmitoylethanolamide...

  8. Discovery of MK-3168: A PET Tracer for Imaging Brain Fatty Acid Amide Hydrolase.

    Liu, Ping; Hamill, Terence G; Chioda, Marc; Chobanian, Harry; Fung, Selena; Guo, Yan; Chang, Linda; Bakshi, Raman; Hong, Qingmei; Dellureficio, James; Lin, Linus S; Abbadie, Catherine; Alexander, Jessica; Jin, Hong; Mandala, Suzanne; Shiao, Lin-Lin; Li, Wenping; Sanabria, Sandra; Williams, David; Zeng, Zhizhen; Hajdu, Richard; Jochnowitz, Nina; Rosenbach, Mark; Karanam, Bindhu; Madeira, Maria; Salituro, Gino; Powell, Joyce; Xu, Ling; Terebetski, Jenna L; Leone, Joseph F; Miller, Patricia; Cook, Jacquelynn; Holahan, Marie; Joshi, Aniket; O'Malley, Stacey; Purcell, Mona; Posavec, Diane; Chen, Tsing-Bau; Riffel, Kerry; Williams, Mangay; Hargreaves, Richard; Sullivan, Kathleen A; Nargund, Ravi P; DeVita, Robert J

    2013-06-13

    We report herein the discovery of a fatty acid amide hydrolase (FAAH) positron emission tomography (PET) tracer. Starting from a pyrazole lead, medicinal chemistry efforts directed toward reducing lipophilicity led to the synthesis of a series of imidazole analogues. Compound 6 was chosen for further profiling due to its appropriate physical chemical properties and excellent FAAH inhibition potency across species. [(11)C]-6 (MK-3168) exhibited good brain uptake and FAAH-specific signal in rhesus monkeys and is a suitable PET tracer for imaging FAAH in the brain. PMID:24900701

  9. Fatty Acid Amide Hydrolase (FAAH) Inhibition Enhances Memory Acquisition through Activation of PPAR-alpha Nuclear Receptors

    Mazzola, Carmen; Medalie, Julie; Scherma, Maria; Panlilio, Leigh V.; Solinas, Marcello; Tanda, Gianluigi; Drago, Filippo; Cadet, Jean Lud; Goldberg, Steven R.; Yasar, Sevil

    2009-01-01

    Inhibitors of fatty acid amide hydrolase (FAAH) increase endogenous levels of anandamide (a cannabinoid CB[subscript 1]-receptor ligand) and oleoylethanolamide and palmitoylethanolamide (OEA and PEA, ligands for alpha-type peroxisome proliferator-activated nuclear receptors, PPAR-alpha) when and where they are naturally released in the brain.…

  10. Overexpression of fatty acid amide hydrolase induces early flowering in Arabidopsis thaliana

    Neal D. Teaster

    2012-02-01

    Full Text Available N-Acylethanolamines (NAEs are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE. In animal systems this reaction is part of the endocannabinoid signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH, which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440 lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA, enhanced susceptibility to bacterial pathogens, and early flowering. Here we investigated the nature of the early flowering phenotype of AtFAAH overexpression. AtFAAH overexpressors flowered several days earlier than wild type and AtFAAH knockouts under both non-inductive short day (SD and inductive long day (LD conditions. Microarray analysis revealed that the FLOWERING LOCUS T (FT gene, which plays a major role in regulating flowering time, and one target MADS box transcription factor, SEPATALLA3 (SEP3, were elevated in AtFAAH overexpressors. Furthermore, AtFAAH overexpressors, with the early flowering phenotype had lower endogenous NAE levels in leaves compared to wild type prior to flowering. Exogenous application of NAE 12:0, which was reduced by up to 30% in AtFAAH overexpressors, delayed the onset of flowering in wild type plants. We conclude that the early flowering phenotype of AtFAAH overexpressors is, in part, explained by elevated FT gene expression resulting from the enhanced NAE hydrolase activity of AtFAAH, suggesting that NAE metabolism may participate in floral signaling pathways.

  11. Fatty acid amide hydrolase (FAAH) inhibition enhances memory acquisition through activation of PPAR-α nuclear receptors

    Mazzola, Carmen; Medalie, Julie; Scherma, Maria; Panlilio, Leigh V; Solinas, Marcello; Tanda, Gianluigi; Drago, Filippo; Cadet, Jean Lud; Goldberg, Steven R.; Yasar, Sevil

    2009-01-01

    Inhibitors of fatty acid amide hydrolase (FAAH) increase endogenous levels of anandamide (a cannabinoid CB1-receptor ligand) and oleoylethanolamide and palmitoylethanolamide (OEA and PEA, ligands for α-type peroxisome proliferator-activated nuclear receptors, PPAR-α) when and where they are naturally released in the brain. Using a passive-avoidance task in rats, we found that memory acquisition was enhanced by the FAAH inhibitor URB597 or by the PPAR-α agonist WY14643, and these enhancements ...

  12. Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase: New Targets for Future Antidepressants.

    Ogawa, Shintaro; Kunugi, Hiroshi

    2015-01-01

    Cannabis and analogs of Δ9-tetrahydrocannabinol have been used for therapeutic purposes, but their therapeutic use remains limited because of various adverse effects. Endogenous cannabinoids have been discovered, and dysregulation of endocannabinoid signaling is implicated in the pathophysiology of major depressive disorder (MDD). Recently, endocannabinoid hydrolytic enzymes such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have become new therapeutic targets in the treatment of MDD. Several FAAH or MAGL inhibitors are reported to have no cannabimimetic side effects and, therefore, are new potential therapeutic options for patients with MDD who are resistant to first-line antidepressants (selective serotonin and serotonin-norepinephrine reuptake inhibitors). In this review, we focus on the possible relationships between MDD and the endocannabinoid system as well as the inhibitors' therapeutic potential. MAGL inhibitors may reduce inflammatory responses through activation of cannabinoid receptor type 2. In the hypothalamic-pituitary-adrenal axis, repeated FAAH inhibitor administration may be beneficial for reducing circulating glucocorticoid levels. Both FAAH and MAGL inhibitors may contribute to dopaminergic system regulation. Recently, several new inhibitors have been developed with strong potency and selectivity. FAAH inhibitor, MAGL inhibitor, or dual blocker use would be promising new treatments for MDD. Further pre-clinical studies and clinical trials using these inhibitors are warranted. PMID:26630956

  13. A pro-nociceptive phenotype unmasked in mice lacking fatty-acid amide hydrolase.

    Carey, Lawrence M; Slivicki, Richard A; Leishman, Emma; Cornett, Ben; Mackie, Ken; Bradshaw, Heather; Hohmann, Andrea G

    2016-02-01

    Fatty-acid amide hydrolase (FAAH) is the major enzyme responsible for degradation of anandamide, an endocannabinoid. Pharmacological inhibition or genetic deletion of FAAH (FAAH KO) produces antinociception in preclinical pain models that is largely attributed to anandamide-induced activation of cannabinoid receptors. However, FAAH metabolizes a wide range of structurally related, biologically active lipid signaling molecules whose functions remain largely unknown. Some of these endogenous lipids, including anandamide itself, may exert pro-nociceptive effects under certain conditions. In our study, FAAH KO mice exhibited a characteristic analgesic phenotype in the tail flick test and in both formalin and carrageenan models of inflammatory nociception. Nonetheless, intradermal injection of the transient receptor potential channel V1 (TRPV1) agonist capsaicin increased nocifensive behavior as well as mechanical and heat hypersensitivity in FAAH KO relative to wild-type mice. This pro-nociceptive phenotype was accompanied by increases in capsaicin-evoked Fos-like immunoreactive (FLI) cells in spinal dorsal horn regions implicated in nociceptive processing and was attenuated by CB1 (AM251) and TRPV1 (AMG9810) antagonists. When central sensitization was established, FAAH KO mice displayed elevated levels of anandamide, other fatty-acid amides, and endogenous TRPV1 agonists in both paw skin and lumbar spinal cord relative to wild-type mice. Capsaicin decreased spinal cord 2-AG levels and increased arachidonic acid and prostaglandin E2 levels in both spinal cord and paw skin irrespective of genotype. Our studies identify a previously unrecognized pro-nociceptive phenotype in FAAH KO mice that was unmasked by capsaicin challenge. The heightened nociceptive response was mediated by CB1 and TRPV1 receptors and accompanied by enhanced spinal neuronal activation. Moreover, genetic deletion of FAAH has a profound impact on the peripheral and central lipidome. Thus, genetic

  14. Discovery of a Potent, Selective, and Efficacious Class of Reversible α-Ketoheterocycle Inhibitors of Fatty Acid Amide Hydrolase Effective as Analgesicsa

    Boger, Dale L.; Miyauchi, Hiroshi; Du, Wu; Hardouin, Christophe; Fecik, Robert A.; Cheng, Heng; Hwang, Inkyu; Hedrick, Michael P.; Leung, Donmienne; Acevedo, Orlando; Guimarães, Cristiano R. W.; Jorgensen, William L.; Cravatt, Benjamin F.

    2005-01-01

    Fatty acid amide hydrolase (FAAH) degrades neuromodulating fatty acid amides including anandamide (endogenous cannabinoid agonist) and oleamide (sleep-inducing lipid) at their sites of action and is intimately involved in their regulation. Herein we report the discovery of a potent, selective, and efficacious class of reversible FAAH inhibitors that produce analgesia in animal models validating a new therapeutic target for pain intervention. Key to the useful inhibitor discovery was the routi...

  15. Oxygenated metabolites of anandamide and 2-arachidonoylglycerol : conformational analysis and interaction with cannabinoid receptors, membrane transporter, and fatty acid amide hydrolase

    Vliegenthart, J.F.G.; Stelt, M. van der; Kuik, J.A. van; Zadelhoff, G. van; Leeflang, B.R.; Veldink, G.A.; Finazzi Agrò, A.; Maccarrone, M.

    2002-01-01

    This study was aimed at finding structural requirements for the interaction of the acyl chain of endocannabinoids with cannabinoid receptors, membrane transporter protein, and fatty acid amide hydrolase (FAAH). To this end, the flexibility of the acyl chain was restricted by introduction of an 1-hyd

  16. Intracellular Self-Assembly of Cyclic d-Luciferin Nanoparticles for Persistent Bioluminescence Imaging of Fatty Acid Amide Hydrolase.

    Yuan, Yue; Wang, Fuqiang; Tang, Wei; Ding, Zhanling; Wang, Lin; Liang, Lili; Zheng, Zhen; Zhang, Huafeng; Liang, Gaolin

    2016-07-26

    Fatty acid amide hydrolase (FAAH) overexpression induces several disorder symptoms in nerve systems, and therefore long-term tracing of FAAH activity in vivo is of high importance but remains challenging. Current bioluminescence (BL) methods are limited in detecting FAAH activity within 5 h. Herein, by rational design of a latent BL probe (d-Cys-Lys-CBT)2 (1), we developed a "smart" method of intracellular reduction-controlled self-assembly and FAAH-directed disassembly of its cyclic d-luciferin-based nanoparticles (i.e., 1-NPs) for persistent BL imaging of FAAH activity in vitro, in cells, and in vivo. Using aminoluciferin methyl amide (AMA), Lys-amino-d-luciferin (Lys-Luc), and amino-d-luciferin (NH2-Luc) as control BL probes, we validated that the persistent BL of 1 from luciferase-expressing cells or tumors was controlled by the activity of intracellular FAAH. With the property of long-term tracing of FAAH activity in vivo of 1, we envision that our BL precursor 1 could probably be applied for in vivo screening of FAAH inhibitors and the diagnosis of their related diseases (or disorders) in the future. PMID:27348334

  17. Physical Nature of Fatty Acid Amide Hydrolase Interactions with Its Inhibitors: Testing a Simple Nonempirical Scoring Model.

    Giedroyć-Piasecka, Wiktoria; Dyguda-Kazimierowicz, Edyta; Beker, Wiktor; Mor, Marco; Lodola, Alessio; Sokalski, W Andrzej

    2014-12-26

    Fatty acid amide hydrolase (FAAH) is an enzyme responsible for the deactivating hydrolysis of fatty acid ethanolamide neuromodulators. FAAH inhibitors have gained considerable interest due to their possible application in the treatment of anxiety, inflammation, and pain. In the context of inhibitor design, the availability of reliable computational tools for predicting binding affinity is still a challenging task, and it is now well understood that empirical scoring functions have several limitations that in principle could be overcome by quantum mechanics. Herein, systematic ab initio analyses of FAAH interactions with a series of inhibitors belonging to the class of the N-alkylcarbamic acid aryl esters have been performed. In contrast to our earlier studies of other classes of enzyme-inhibitor complexes, reasonable correlation with experimental results required us to consider correlation effects along with electrostatic term. Therefore, the simplest comprehensive nonempirical model allowing for qualitative predictions of binding affinities for FAAH ligands consists of electrostatic multipole and second-order dispersion terms. Such a model has been validated against the relative stabilities of the benchmark S66 set of biomolecular complexes. As it does not involve parameters fitted to experimentally derived data, this model offers a unique opportunity for generally applicable inhibitor design and virtual screening. PMID:25420234

  18. Inhibitors of monoacylglycerol lipase, fatty-acid amide hydrolase and endocannabinoid transport differentially suppress capsaicin-induced behavioral sensitization through peripheral endocannabinoid mechanisms

    Spradley, Jessica M.; Guindon, Josée; Hohmann, Andrea G.

    2010-01-01

    Monoacylglycerol lipase (MGL) and fatty acid amide hydrolase (FAAH) degrade the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA), respectively. Pharmacological inhibition of these enzymes in the periphery may elucidate the role of endocannabinoids in controlling nociceptive transmission. We compared effects of the MGL inhibitor JZL184, the FAAH inhibitor URB597, and the endocannabinoid uptake inhibitor VDM11, administered locally in the paw, on behavioral hypersensitivities...

  19. Pharmacological blockade of the fatty acid amide hydrolase (FAAH) alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothalamus and striatum in a negative energy context

    Laura Bindila; Antoni Pastor; Margarita Pérez-Martín; Rafael De La Torre; Juan Suarez

    2015-01-01

    Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3+ or BrdU+ cells) of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3+), astroglia (GFAP+), and microglia (Iba1+ cells) were analyzed in the hippocampus, hypothalamus and striatum o...

  20. Pharmacological blockade of the fatty acid amide hydrolase (FAAH) alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothalamus and striatum in a negative energy context.

    Rivera, Patricia; Bindila, Laura; Pastor, Antoni; Pérez-Martín, Margarita; Pavón, Francisco J.; Serrano, Antonia; de la Torre, Rafael; Lutz, Beat; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2015-01-01

    Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3(+) or BrdU(+) cells) of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3(+)), astroglia (GFAP(+)), and microglia (Iba1(+) cells) were analyzed in the hippocampus, hypothalamus and ...

  1. Dysfunction in fatty acid amide hydrolase is associated with depressive-like behavior in Wistar Kyoto rats.

    K Yaragudri Vinod

    Full Text Available BACKGROUND: While the etiology of depression is not clearly understood at the present time, this mental disorder is thought be a complex and multifactorial trait with important genetic and environmental contributing factors. METHODOLOGY/PRINCIPAL FINDINGS: The role of the endocannabinoid (eCB system in depressive behavior was examined in Wistar Kyoto (WKY rat strain, a genetic model of depression. Our findings revealed selective abnormalities in the eCB system in the brains of WKY rats compared to Wistar (WIS rats. Immunoblot analysis indicated significantly higher levels of fatty acid amide hydrolase (FAAH in frontal cortex and hippocampus of WKY rats with no alteration in the level of N-arachidonyl phosphatidyl ethanolamine specific phospholipase-D (NAPE-PLD. Significantly higher levels of CB1 receptor-mediated G-protein coupling and lower levels of anandamide (AEA were found in frontal cortex and hippocampus of WKY rats. While the levels of brain derived neurotropic factor (BDNF were significantly lower in frontal cortex and hippocampus of WKY rats compared to WIS rats, pharmacological inhibition of FAAH elevated BDNF levels in WKY rats. Inhibition of FAAH enzyme also significantly increased sucrose consumption and decreased immobility in the forced swim test in WKY rats. CONCLUSIONS/SIGNIFICANCE: These findings suggest a critical role for the eCB system and BDNF in the genetic predisposition to depressive-like behavior in WKY rats and point to the potential therapeutic utility of eCB enhancing agents in depressive disorder.

  2. Effect of cannabidiol on sepsis-induced motility disturbances in mice: involvement of CB receptors and fatty acid amide hydrolase.

    de Filippis, D; Iuvone, T; d'amico, A; Esposito, G; Steardo, L; Herman, A G; Pelckmans, P A; de Winter, B Y; de Man, J G

    2008-08-01

    Sepsis is an inflammatory condition that is associated with reduced propulsive gastrointestinal motility (ileus). A therapeutic option to treat sepsis is to promote intestinal propulsion preventing bacterial stasis, overgrowth and translocation. Recent evidence suggests that anti-oxidants improve sepsis-induced ileus. Cannabidiol, a non-psychotropic component of Cannabis sativa, exerts strong anti-oxidant and anti-inflammatory effects without binding to cannabinoid CB(1) or CB(2) receptors. Cannabidiol also regulates the activity of fatty acid amide hydrolase (FAAH) which is the main enzyme involved in endocannabinoid breakdown and which modulates gastrointestinal motility. Because of the therapeutic potential of cannabidiol in several pathologies, we investigated its effect on sepsis-induced ileus and on cannabinoid receptor and FAAH expression in the mouse intestine. Sepsis was induced by treating mice with lipopolysaccharides for 18 h. Sepsis led to a decrease in gastric emptying and intestinal transit. Cannabidiol further reduced gastrointestinal motility in septic mice but did not affect gastrointestinal motility in control mice. A low concentration of the CB(1) antagonist AM251 did not affect gastrointestinal motility in control mice but reversed the effect of cannabidiol in septic mice. Sepsis was associated with a selective upregulation of intestinal CB(1) receptors without affecting CB(2) receptor expression and with increased FAAH expression. The increase in FAAH expression was completely reversed by cannabidiol but not affected by AM251. Our results show that sepsis leads to an imbalance of the endocannabinoid system in the mouse intestine. Despite its proven anti-oxidant and anti-inflammatory properties, cannabidiol may be of limited use for the treatment of sepsis-induced ileus. PMID:18373655

  3. Fatty acid amide hydrolase-dependent generation of antinociceptive drug metabolites acting on TRPV1 in the brain.

    David A Barrière

    Full Text Available The discovery that paracetamol is metabolized to the potent TRPV1 activator N-(4-hydroxyphenyl-5Z,8Z,11Z,14Z-eicosatetraenamide (AM404 and that this metabolite contributes to paracetamol's antinociceptive effect in rodents via activation of TRPV1 in the central nervous system (CNS has provided a potential strategy for developing novel analgesics. Here we validated this strategy by examining the metabolism and antinociceptive activity of the de-acetylated paracetamol metabolite 4-aminophenol and 4-hydroxy-3-methoxybenzylamine (HMBA, both of which may undergo a fatty acid amide hydrolase (FAAH-dependent biotransformation to potent TRPV1 activators in the brain. Systemic administration of 4-aminophenol and HMBA led to a dose-dependent formation of AM404 plus N-(4-hydroxyphenyl-9Z-octadecenamide (HPODA and arvanil plus olvanil in the mouse brain, respectively. The order of potency of these lipid metabolites as TRPV1 activators was arvanil = olvanil>>AM404> HPODA. Both 4-aminophenol and HMBA displayed antinociceptive activity in various rodent pain tests. The formation of AM404, arvanil and olvanil, but not HPODA, and the antinociceptive effects of 4-aminophenol and HMBA were substantially reduced or disappeared in FAAH null mice. The activity of 4-aminophenol in the mouse formalin, von Frey and tail immersion tests was also lost in TRPV1 null mice. Intracerebroventricular injection of the TRPV1 blocker capsazepine eliminated the antinociceptive effects of 4-aminophenol and HMBA in the mouse formalin test. In the rat, pharmacological inhibition of FAAH, TRPV1, cannabinoid CB1 receptors and spinal 5-HT3 or 5-HT1A receptors, and chemical deletion of bulbospinal serotonergic pathways prevented the antinociceptive action of 4-aminophenol. Thus, the pharmacological profile of 4-aminophenol was identical to that previously reported for paracetamol, supporting our suggestion that this drug metabolite contributes to paracetamol's analgesic activity via

  4. Fatty Acid Amide Hydrolase-Dependent Generation of Antinociceptive Drug Metabolites Acting on TRPV1 in the Brain

    Blomgren, Anders; Simonsen, Charlotte; Daulhac, Laurence; Libert, Frédéric; Chapuy, Eric; Etienne, Monique; Högestätt, Edward D.; Zygmunt, Peter M.; Eschalier, Alain

    2013-01-01

    The discovery that paracetamol is metabolized to the potent TRPV1 activator N-(4-hydroxyphenyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (AM404) and that this metabolite contributes to paracetamol’s antinociceptive effect in rodents via activation of TRPV1 in the central nervous system (CNS) has provided a potential strategy for developing novel analgesics. Here we validated this strategy by examining the metabolism and antinociceptive activity of the de-acetylated paracetamol metabolite 4-aminophenol and 4-hydroxy-3-methoxybenzylamine (HMBA), both of which may undergo a fatty acid amide hydrolase (FAAH)-dependent biotransformation to potent TRPV1 activators in the brain. Systemic administration of 4-aminophenol and HMBA led to a dose-dependent formation of AM404 plus N-(4-hydroxyphenyl)-9Z-octadecenamide (HPODA) and arvanil plus olvanil in the mouse brain, respectively. The order of potency of these lipid metabolites as TRPV1 activators was arvanil = olvanil>>AM404> HPODA. Both 4-aminophenol and HMBA displayed antinociceptive activity in various rodent pain tests. The formation of AM404, arvanil and olvanil, but not HPODA, and the antinociceptive effects of 4-aminophenol and HMBA were substantially reduced or disappeared in FAAH null mice. The activity of 4-aminophenol in the mouse formalin, von Frey and tail immersion tests was also lost in TRPV1 null mice. Intracerebroventricular injection of the TRPV1 blocker capsazepine eliminated the antinociceptive effects of 4-aminophenol and HMBA in the mouse formalin test. In the rat, pharmacological inhibition of FAAH, TRPV1, cannabinoid CB1 receptors and spinal 5-HT3 or 5-HT1A receptors, and chemical deletion of bulbospinal serotonergic pathways prevented the antinociceptive action of 4-aminophenol. Thus, the pharmacological profile of 4-aminophenol was identical to that previously reported for paracetamol, supporting our suggestion that this drug metabolite contributes to paracetamol’s analgesic activity via activation

  5. [11C]CURB: Evaluation of a novel radiotracer for imaging fatty acid amide hydrolase by positron emission tomography

    Introduction: Fatty acid amide hydrolase (FAAH) is the enzyme responsible for metabolising the endogenous cannabinoid, anandamide, and thus represents an important target for molecular imaging. To date, no radiotracer has been shown to be useful for imaging of FAAH using either positron emission tomography (PET) or single photon emission computed tomography (SPECT). We here determine the suitability of a novel carbon-11-labeled inhibitor of FAAH via ex vivo biodistribution studies in rat brain in conjunction with pharmacological challenges. Methods: A potent irreversible inhibitor of FAAH, URB694, radiolabeled with carbon-11 in the carbonyl position ([11C]CURB), was administered to male rats via tail-vein injection. Rats were sacrificed at various time points postinjection, and tissue samples were dissected, counted and weighed. Specific binding to FAAH was investigated by pretreatment of animals with URB694 or URB597. For metabolism and mechanism of binding studies, whole brains were excised post-radiotracer injection, homogenised and extracted exhaustively with 80% aq. acetonitrile to determine the time course and fraction of radioactivity that was irreversibly bound to brain parenchyma. Results: Upon intravenous injection into rats, [11C]CURB showed high brain uptake [standard uptake value (SUV) of 1.6-2.4 at 5 min] with little washout over time, which is characteristic of irreversible binding. Highest uptake of radioactivity was seen in the cortex, intermediate in the cerebellum and lowest in the hypothalamus, reflecting the reported distribution of FAAH. Brain uptake of radioactivity was decreased in a dose-dependent manner by pretreatment with increasing amounts of URB694, demonstrating that binding was saturable. Pretreatment with the well-characterised FAAH inhibitor, URB597, reduced binding in all brain regions by 70-80%. Homogenised brain extraction experiments demonstrated unequivocally that [11C]CURB was irreversibly bound to FAAH. Conclusions: The

  6. Synthesis and preclinical evaluation of [11C-carbonyl]PF-04457845 for neuroimaging of fatty acid amide hydrolase

    Introduction: Fatty acid amide hydrolase (FAAH) has a significant role in regulating endocannabinoid signaling in the central nervous system. As such, FAAH inhibitors are being actively sought for pain, addiction, and other indications. This has led to the recent pursuit of positron emission tomography (PET) radiotracers targeting FAAH. We report herein the preparation and preclinical evaluation of [11C-carbonyl]PF-04457845, an isotopologue of the potent irreversible FAAH inhibitor. Methods: PF-04457845 was radiolabeled at the carbonyl position via automated [11C]CO2-fixation. Ex vivo brain biodistribution of [11C-carbonyl]PF-04457845 was carried out in conscious rats. Specificity was determined by pre-administration of PF-04457845 or URB597 prior to [11C-carbonyl]PF-04457845. In a separate experiment, rats injected with the title radiotracer had whole brains excised, homogenized and extracted to examine irreversible binding to brain parenchyma. Results: The title compound was prepared in 5 ± 1% (n = 4) isolated radiochemical yield based on starting [11C]CO2 (decay uncorrected) within 25 min from end-of-bombardment in > 98% radiochemical purity and a specific activity of 73.5 ± 8.2 GBq/μmol at end-of-synthesis. Uptake of [11C-carbonyl]PF-04457845 into the rat brain was high (range of 1.2–4.4 SUV), heterogeneous, and in accordance with reported FAAH distribution. Saturable binding was demonstrated by a dose-dependent reduction in brain radioactivity uptake following pre-treatment with PF-04457845. Pre-treatment with the prototypical FAAH inhibitor, URB597, reduced the brain radiotracer uptake in all regions by 71–81%, demonstrating specificity for FAAH. The binding of [11C-carbonyl]PF-04457845 to FAAH at 40 min post injection was irreversible as 98% of the radioactivity in the brain could not be extracted. Conclusions: [11C-carbonyl]PF-04457845 was rapidly synthesized via an automated radiosynthesis. Ex vivo biodistribution studies in conscious rodents

  7. [{sup 11}C]CURB: Evaluation of a novel radiotracer for imaging fatty acid amide hydrolase by positron emission tomography

    Wilson, Alan A., E-mail: alan.wilson@camhpet.c [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Garcia, Armando; Parkes, Jun [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Houle, Sylvain [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Tong, Junchao [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8 (Canada); Vasdev, Neil [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada)

    2011-02-15

    Introduction: Fatty acid amide hydrolase (FAAH) is the enzyme responsible for metabolising the endogenous cannabinoid, anandamide, and thus represents an important target for molecular imaging. To date, no radiotracer has been shown to be useful for imaging of FAAH using either positron emission tomography (PET) or single photon emission computed tomography (SPECT). We here determine the suitability of a novel carbon-11-labeled inhibitor of FAAH via ex vivo biodistribution studies in rat brain in conjunction with pharmacological challenges. Methods: A potent irreversible inhibitor of FAAH, URB694, radiolabeled with carbon-11 in the carbonyl position ([{sup 11}C]CURB), was administered to male rats via tail-vein injection. Rats were sacrificed at various time points postinjection, and tissue samples were dissected, counted and weighed. Specific binding to FAAH was investigated by pretreatment of animals with URB694 or URB597. For metabolism and mechanism of binding studies, whole brains were excised post-radiotracer injection, homogenised and extracted exhaustively with 80% aq. acetonitrile to determine the time course and fraction of radioactivity that was irreversibly bound to brain parenchyma. Results: Upon intravenous injection into rats, [{sup 11}C]CURB showed high brain uptake [standard uptake value (SUV) of 1.6-2.4 at 5 min] with little washout over time, which is characteristic of irreversible binding. Highest uptake of radioactivity was seen in the cortex, intermediate in the cerebellum and lowest in the hypothalamus, reflecting the reported distribution of FAAH. Brain uptake of radioactivity was decreased in a dose-dependent manner by pretreatment with increasing amounts of URB694, demonstrating that binding was saturable. Pretreatment with the well-characterised FAAH inhibitor, URB597, reduced binding in all brain regions by 70-80%. Homogenised brain extraction experiments demonstrated unequivocally that [{sup 11}C]CURB was irreversibly bound to FAAH

  8. The synthesis and in vivo evaluation of [18F]PF-9811: a novel PET ligand for imaging brain fatty acid amide hydrolase (FAAH)

    Introduction: Fatty acid amide hydrolase (FAAH) is responsible for the enzymatic degradation of the fatty acid amide family of signaling lipids, including the endogenous cannabinoid (endocannabinoid) anandamide. The involvement of the endocannabinoid system in pain and other nervous system disorders has made FAAH an attractive target for drug development. Companion molecular imaging probes are needed, however, to assess FAAH inhibition in the nervous system in vivo. We report here the synthesis and in vivo evaluation of [18F]PF-9811, a novel PET ligand for non-invasive imaging of FAAH in the brain. Methods: The potency and selectivity of unlabeled PF-9811 were determined by activity-based protein profiling (ABPP) both in vitro and in vivo. [18F]PF-9811 was synthesized in a 3-step, one-pot reaction sequence, followed by HPLC purification. Biological evaluation was performed by biodistribution and dynamic PET imaging studies in male rats. The specificity of [18F]PF-9811 uptake was evaluated by pre-administration of PF-04457845, a potent and selective FAAH inhibitor, 1 h prior to radiotracer injection. Results: Biodistribution studies show good uptake (SUV ∼ 0.8 at 90 min) of [18F]PF-9811 in rat brain, with significant reduction of the radiotracer in all brain regions (37%–73% at 90 min) in blocking experiments. Dynamic PET imaging experiments in rat confirmed the heterogeneous uptake of [18F]PF-9811 in brain regions with high FAAH enzymatic activity, as well as statistically significant reductions in signal following pre-administration of the blocking compound PF-04457845. Conclusions: [18F]PF-9811 is a promising PET imaging agent for FAAH. Biodistribution and PET imaging experiments show that the tracer has good uptake in brain, regional heterogeneity, and specific binding as determined by blocking experiments with the highly potent and selective FAAH inhibitor, PF-04457845.

  9. Effects of fatty acid amide hydrolase inhibition on neuronal responses to nicotine, cocaine and morphine in the nucleus accumbens shell and ventral tegmental area: involvement of PPAR-α nuclear receptors

    Luchicchi, Antonio; Lecca, Salvatore; Carta, Stefano; Pillolla, Giuliano; Muntoni, Anna Lisa; Yasar, Sevil; Goldberg, Steven R.; Pistis, Marco

    2010-01-01

    The endocannabinoid system regulates neurotransmission in brain regions relevant to neurobiological and behavioral actions of addicting drugs. We recently demonstrated that inhibition by URB597 of fatty acid amide hydrolase (FAAH), the main enzyme which degrades the endogenous cannabinoid N-acylethanolamine (NAE) anandamide and the endogenous non-cannabinoid NAEs oleoylethanolamide and palmitoylethanolamide, blocks nicotine-induced excitation of ventral tegmental area (VTA) dopamine (DA) neur...

  10. Pharmacological blockade of the fatty acid amide hydrolase (FAAH alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothalamus and striatum in a negative energy context

    Patricia eRivera

    2015-03-01

    Full Text Available Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3+ or BrdU+ cells of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3+, astroglia (GFAP+, and microglia (Iba1+ cells were analyzed in the hippocampus, hypothalamus and striatum of rats intraperitoneally treated with URB597 (0.3 mg/kg/day at one dose/4-days resting or 5 doses (1 dose/day. Repeated URB597 treatment increased the plasma levels of the endocannabinoids oleoylethanolamide, palmitoylethanolamide and arachidonoylethanolamine, reduced the plasma levels of glucose, triglycerides and cholesterol, and induced a transitory body weight decrease. The hippocampi of repeated URB597-treated rats showed a reduced number of phospho-H3+ and BrdU+ subgranular cells as well as GFAP+, Iba1+ and cleaved caspase-3+ cells, which was accompanied with decreased hippocampal expressions of cannabinoid CB1 receptor and FAAH. In the hypothalami of these rats, the number of phospho-H3+, GFAP+ and 3-weeks-old BrdU+ cells was specifically decreased. The reduced striatal expression of CB1 receptor in repeated URB597-treated rats was only associated with a reduced apoptosis. In contrast, the striatum of acute URB597-treated rats showed an increased number of subventricular proliferative, astroglial and apoptotic cells, which was accompanied with increased Faah expression. Main results indicated that FAAH inhibitor URB597 decreased neural proliferation, glia and apoptosis in a brain region-dependent manner, which were coupled to local changes in FAAH and/or CB1 receptor expressions and a negative energy context.

  11. Pharmacological blockade of the fatty acid amide hydrolase (FAAH) alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothalamus and striatum in a negative energy context.

    Rivera, Patricia; Bindila, Laura; Pastor, Antoni; Pérez-Martín, Margarita; Pavón, Francisco J; Serrano, Antonia; de la Torre, Rafael; Lutz, Beat; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2015-01-01

    Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3(+) or BrdU(+) cells) of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3(+)), astroglia (GFAP(+)), and microglia (Iba1(+) cells) were analyzed in the hippocampus, hypothalamus and striatum of rats intraperitoneally treated with URB597 (0.3 mg/kg/day) at one dose/4-days resting or 5 doses (1 dose/day). Repeated URB597 treatment increased the plasma levels of the N-acylethanolamines oleoylethanolamide, palmitoylethanolamide and arachidonoylethanolamine, reduced the plasma levels of glucose, triglycerides and cholesterol, and induced a transitory body weight decrease. The hippocampi of repeated URB597-treated rats showed a reduced number of phospho-H3(+) and BrdU(+) subgranular cells as well as GFAP(+), Iba1(+) and cleaved caspase-3(+) cells, which was accompanied with decreased hippocampal expression of the cannabinoid CB1 receptor gene Cnr1 and Faah. In the hypothalami of these rats, the number of phospho-H3(+), GFAP(+) and 3-weeks-old BrdU(+) cells was specifically decreased. The reduced striatal expression of CB1 receptor in repeated URB597-treated rats was only associated with a reduced apoptosis. In contrast, the striatum of acute URB597-treated rats showed an increased number of subventricular proliferative, astroglial and apoptotic cells, which was accompanied with increased Faah expression. Main results indicated that FAAH inhibitor URB597 decreased neural proliferation, glia and apoptosis in a brain region-dependent manner, which were coupled to local changes in Faah and/or Cnr1 expression and a negative energy context. PMID:25870539

  12. PET imaging of fatty acid amide hydrolase in the brain: synthesis and biological evaluation of an 11C-labelled URB597 analogue

    Introduction: Fatty acid amide hydrolase (FAAH) is part of the endocannabinoid system (ECS) and has been linked to the aetiology of several neurological and neuropsychiatric disorders. So far no useful PET or SPECT tracer for in vivo visualisation of FAAH has been reported. We synthesized and evaluated a carbon-11-labeled URB597 analogue, biphenyl-3-yl [11C]-4-methoxyphenylcarbamate or [11C]-1, as potential FAAH imaging agent. Methods: The inhibitory activity of 1 was determined in vitro using recombinant FAAH. Radiosynthesis of [11C]-1 was performed by methylation using [11C]-CH3I, followed by HPLC purification. Biological evaluation was done by biodistribution studies in wild-type and FAAH knock-out mice, and by ex vivo and in vivo metabolite analysis. The influence of URB597 pretreatment on the metabolisation profile was assessed. Results: [11C]-1 was obtained in good yields and high radiochemical purity. Biodistribution studies revealed high brain uptake in wild-type and FAAH knock-out mice, but no retention of radioactivity could be demonstrated. Metabolite analysis and URB597 pretreatment confirmed the non-FAAH-mediated metabolisation of [11C]-1. The inhibition mechanism was determined to be reversible. In addition, the inhibition of URB597 appeared slowly reversible. Conclusions: Although [11C]-1 inhibits FAAH in vitro and displays high brain uptake, the inhibition mechanism seems to deviate from the proposed carbamylation mechanism. Consequently, it does not covalently bind to FAAH and will not be useful for mapping the enzyme in vivo. However, it represents a potential starting point for the development of in vivo FAAH imaging tools.

  13. Lipopolysaccharide-induced pulmonary inflammation is not accompanied by a release of anandamide into the lavage fluid or a down-regulation of the activity of fatty acid amide hydrolase

    Holt, S.; J. Fowler, C.; Rocksén, D.; Bucht, A.; Petersen, G.; Hansen, Harald S.; Valenti, M.; Di Marzo, V.

    2004-01-01

    lavage (BAL) fluid, which was not accompanied by epithelial cell injury. The treatment, however, did not change significantly the levels of anandamide and the related compound palmitoylethanolamide in the cell-free fraction of the BAL fluid. The activities of the anandamide synthetic enzymes N...... inhibitor of lung fatty acid amide hydrolase than expected from the literature, and a dose of 30 mg/kg i.p. of this compound, which produced a complete inhibition of brain anandamide metabolism, only partially inhibited the lung metabolic activity. © 2004 Elsevier Inc. All rights reserved....

  14. The fatty acid amide hydrolase inhibitor URB597 exerts anti-inflammatory effects in hippocampus of aged rats and restores an age-related deficit in long-term potentiation

    Murphy Niamh

    2012-04-01

    Full Text Available Abstract Background Several factors contribute to the deterioration in synaptic plasticity which accompanies age and one of these is neuroinflammation. This is characterized by increased microglial activation associated with increased production of proinflammatory cytokines like interleukin-1β (IL-1β. In aged rats these neuroinflammatory changes are associated with a decreased ability of animals to sustain long-term potentiation (LTP in the dentate gyrus. Importantly, treatment of aged rats with agents which possess anti-inflammatory properties to decrease microglial activation, improves LTP. It is known that endocannabinoids, such as anandamide (AEA, have anti-inflammatory properties and therefore have the potential to decrease the age-related microglial activation. However, endocannabinoids are extremely labile and are hydrolyzed quickly after production. Here we investigated the possibility that inhibiting the degradation of endocannabinoids with the fatty acid amide hydrolase (FAAH inhibitor, URB597, could ameliorate age-related increases in microglial activation and the associated decrease in LTP. Methods Young and aged rats received subcutaneous injections of the FAAH inhibitor URB597 every second day and controls which received subcutaneous injections of 30% DMSO-saline every second day for 28 days. Long-term potentiation was recorded on day 28 and the animals were sacrificed. Brain tissue was analyzed for markers of microglial activation by PCR and for levels of endocannabinoids by liquid chromatography coupled to tandem mass spectrometry. Results The data indicate that expression of markers of microglial activation, MHCII, and CD68 mRNA, were increased in the hippocampus of aged, compared with young, rats and that these changes were associated with increased expression of the proinflammatory cytokines interleukin (IL-1β and tumor necrosis factor-α (TNFα which were attenuated by treatment with URB597. Coupled with these changes, we

  15. Metal extraction by amides of carboxylic acids

    Extraction ability of various amides was studied. Data on extraction of rare earths, vanadium, molybdenum, rhenium, uranium, niobium, tantalum by N,N-dibutyl-amides of acetic, nonanic acids and fatly synthetic acids of C7-C9 fractions are presented. Effect of salting-out agents, inorganic acid concentrations on extraction process was studied. Potential ability of using amides of carboxylic acids for extractional concentration of rare earths as well as for recovery and separation of iron, rhenium, vanadium, molybdenum, uranium, niobium, and tantalum was shown

  16. Metabolism of amino acid amides in Pseudomonas putida ATCC 12633

    Hermes, H.F.M.; Croes, L.M.; Peeters, W.P.H.; Peters, P.J.H.; Dijkhuizen, L.

    1993-01-01

    The metabolism of the natural amino acid L-valine, the unnatural amino acids D-valine, and D-, L-phenylglycine (D-, L-PG), and the unnatural amino acid amides D-, L-phenylglycine amide (D, L-PG-NH2) and L-valine amide (L-Val-NH2) was studied in Pseudomonas putida ATCC 12633. The organism possessed c

  17. Borate esters as convenient reagents for direct amidation of carboxylic acids and transamidation of primary amides

    Starkov, P.; Sheppard, T. D.

    2011-01-01

    Simple borates serve as effective promoters for amide bond formation with a variety of carboxylic acids and amines. With trimethyl or tris(2,2,2-trifluoroethyl) borate, amides are obtained in good to excellent yield and high purity after a simple work-up procedure. Tris(2,2,2-trifluoroethyl) borate can also be used for the straightforward conversion of primary amides to secondary amides via transamidation.

  18. Uranium extraction with phosphoric acid amides

    Extraction of uranium by phosphorus acid monobuthylamide (MBA), dibuthylamid (DBA) and hexabuthyltriamide (HBTA) has meen investigated. The concentration constants of the process are reported. The extraction behaviour of the amides was found to be analogous to that of neutral organophosphorus extragents and to depend on the donor properties of the phosphoryl oxygen, i.e. on the number and nature of substituents by the phosphorus atom. The extraction capacity of the amides is higher than that of the phosphorus acid esters. In nitric acid solutions the highest resistance to hydrolysis was shown by HBTA. The extraction capacity of HBTA is almost insensitive to the nature of the diluting agent, be it a fatty or an aromatic hydrocarbon. With hexane used for dilution, a crystalline complex UO2(NO3)2x2HBTA was isolated

  19. Urea and amide-based inhibitors of the juvenile hormone epoxide hydrolase of the tobacco hornworm (Manduca sexta: Sphingidae).

    Severson, Tonya F; Goodrow, Marvin H; Morisseau, Christophe; Dowdy, Deanna L; Hammock, Bruce D

    2002-12-01

    A new class of inhibitors of juvenile hormone epoxide hydrolase (JHEH) of Manduca sexta and further in vitro characterization of the enzyme are reported. The compounds are based on urea and amide pharmacophores that were previously demonstrated as effective inhibitors of mammalian soluble and microsomal epoxide hydrolases. The best inhibitors against JHEH activity so far within this class are N-[(Z)-9-octadecenyl]-N'-propylurea and N-hexadecyl-N'-propylurea, which inhibited hydrolysis of a surrogate substrate (t-DPPO) with an IC(50) around 90 nM. The importance of substitution number and type was investigated and results indicated that N, N'-disubstitution with asymmetric alkyl groups was favored. Potencies of pharmacophores decreased as follows: amide>urea>carbamate>carbodiimide>thiourea and thiocarbamate for N, N'-disubstituted compounds with symmetric substituents, and urea>amide>carbamate for compounds with asymmetric N, N'-substituents. JHEH hydrolyzes t-DPPO with a K(m) of 65.6 microM and a V(max) of 59 nmol min(-1) mg(-1) and has a substantially lower K(m) of 3.6 microM and higher V(max) of 322 nmol min(-1) mg(-1) for JH III. Although none of these compounds were potent inhibitors of hydrolysis of JH III by JHEH, they are the first leads toward inhibitors of JHEH that are not potentially subject to metabolism through epoxide degradation. PMID:12429126

  20. Relation of C358A polymorphism of the endocannabinoid degrading enzyme fatty acid amide hydrolase (FAAH with obesity and insulin resistance Relación del polimorfismo C358A del enzima del sistema endocanabinoide (hidrolasa amida acida con la obesidad y la resistencia a la insulina

    D. A. de Luis

    2010-12-01

    Full Text Available Background and aims: Recently, it has been demonstrated that the polymorphism 385 C->A of FAAH (fatty acid amide hydrolase was associated with overweight and obesity. The aim of our study was to investigate the relationship of missense polymorphism (cDNA 385 C-A of FAAH gene on obesity anthropometric parameters, cardiovascular risk factors and adipocytokines. Methods: A population of 279 females with obesity (body mass index 30 was analyzed. An indirect calorimetry, tetrapolar electrical bioimpedance, blood pressure, a serial assessment of nutritional intake with 3 days written food records and biochemical analysis (lipid profile, adipocytokines, insulin, CRP and lipoprotein-a were performed. The statistical analysis was performed for the combined C385A and A385A as a group and wild type C385C as second group. Results: One hundred and ninety four patients (69.5% had the genotype C385C (wild type group and 76 (27.2% patients had the genotype C358A or A358A (9 patients, 3.2% (mutant type group. No differences were detected between groups in anthropometric parameters and dietary intakes. Triglycerides (118.9 ± 59.9 mg/dl vs 107.4 + 51.3 mg/dl;p Antecedentes y objetivos: Recientemente, se ha demostrado que el polimorfismo 385 C/A, de FAAH (hidrolasa amida de ácidos grasos se asocia con el sobrepeso y la obesidad. El objetivo de nuestro estudio fue investigar la relación de este polimorfismo del gen de FAAH con parámetros antropométricos, factores de riesgo cardiovascular y adipocitoquinas. Métodos: Una población de 279 mujeres con obesidad (índice de masa corporal> 30 fue analizada. Se realizaron las siguientes determinaciones; calorimetría indirecta, bioimpedancia eléctrica, presión arterial, una evaluación de la ingesta nutricional de 3 días, así como un análisis bioquímico (perfil lipídico, adipocitoquinas, insulina, proteina C reactiva y lipoproteína-(a. El análisis estadístico se realizó combinando C385A y A385A como grupo

  1. Synthesis of new fatty acids amides from aminolysis of fatty acid methyl esters (FAMEs)

    Recent biochemical and pharmacological studies have led to the characterization of different fatty acid amides as a new family of biologically active lipids. Here, we describe the synthesis of new amides from C16:0, 18:0, 18:1 and 18:1, OH fatty acids (FFA) families with cyclic and acyclic amines and demonstrate for the first time that these compounds produce cytotoxic effects. Application of this method to the synthesis of fatty acid amides was performed using the esters aminolysis as a key step and various carboxylic amides were prepared in good yield from fatty acid methyl esters (FAMEs). (author)

  2. New Umami Amides: Structure-Taste Relationship Studies of Cinnamic Acid Derived Amides and the Natural Occurrence of an Intense Umami Amide in Zanthoxylum piperitum.

    Frerot, Eric; Neirynck, Nathalie; Cayeux, Isabelle; Yuan, Yoyo Hui-Juan; Yuan, Yong-Ming

    2015-08-19

    A series of aromatic amides were synthesized from various acids and amines selected from naturally occurring structural frameworks. These synthetic amides were evaluated for umami taste in comparison with monosodium glutamate. The effect of the substitution pattern of both the acid and the amine parts on umami taste was investigated. The only intensely umami-tasting amides were those made from 3,4-dimethoxycinnamic acid. The amine part was more tolerant to structural changes. Amides bearing an alkyl- or alkoxy-substituted phenylethylamine residue displayed a clean umami taste as 20 ppm solutions in water. Ultraperformance liquid chromatography coupled with a high quadrupole-Orbitrap mass spectrometer (UPLC/MS) was subsequently used to show the natural occurrence of these amides. (E)-3-(3,4-Dimethoxyphenyl)-N-(4-methoxyphenethyl)acrylamide was shown to occur in the roots and stems of Zanthoxylum piperitum, a plant of the family Rutaceae growing in Korea, Japan, and China. PMID:26230212

  3. Intramolecular Amide Hydrolysis in N-Methylmaleamic Acid Revisited

    2002-01-01

    The intramolecular amide hydrolysis of N-methylmaleamic acid have been revisited by use of density functional theory and inclusion of solvent effects. The results indicate that concerted reaction mechanism is favored over stepwise reaction mechanism. This is in agreement with the previous theoretical study. Sovlent effects have significant influence on the reaction barrier.

  4. Inhibition of acid hydrolase activity in human granulocytes by PUVA treatment

    The activity of acid hydrolases in peripheral blood granulocytes was determined. No significant differences could be revealed between healthy and psoriatic donors. During PUVA therapy of psoriasis patients the activity of acid hydrolases in granulocytes was moderately decreased in most cases, but the differences were not significant (high individual variability). Isolated granulocytes were treated in vitro with doses of 8-methoxypsoralen and UVA light as can be achieved in situ in the epidermis during PUVA therapy. A reduced acid hydrolases activity was found in the cells after the treatment, which was not due to secretion of the enzyme or cytotoxic damage. The presence of reduced glutathione prevented this effect. Free extracellular acid hydrolases were not inactivated by PUVA. PUVA-treated granulocytes showed an unimpaired superoxide generation after phagocytic stimulation. These results show that an intracellular inactivation of acid hydrolases and possibly other lysosomal enzymes in granulocytes infiltrating the psoriatic epidermis contribute to the antipsoriatic effects of PUVA therapy. (author)

  5. Toxocara canis: Larvicidal activity of fatty acid amides.

    Mata-Santos, Taís; D'Oca, Caroline da Ros Montes; Mata-Santos, Hílton Antônio; Fenalti, Juliana; Pinto, Nitza; Coelho, Tatiane; Berne, Maria Elisabeth; da Silva, Pedro Eduardo Almeida; D'Oca, Marcelo Gonçalves Montes; Scaini, Carlos James

    2016-02-01

    Considering the therapeutic potential of fatty acid amides, the present study aimed to evaluate their in vitro activity against Toxocara canis larvae and their cytotoxicity for the first time. Linoleylpyrrolidilamide was the most potent, with a minimal larvicidal concentration (MLC) of 0.05 mg/mL and 27% cytotoxicity against murine peritoneal macrophages C57BL/6 mice, as assessed by the MTT assay. PMID:26783180

  6. Recent developments in amide synthesis: direct amidation of carboxylic acids and transamidation reactions

    Lanigan, R. M.; Sheppard, T. D.

    2013-01-01

    The synthesis of amides is of huge importance in a wide variety of industrial and academic fields and is of particular significance in the synthesis of pharmaceuticals. Many of the well established methods for amide synthesis involve reagents that are difficult to handle and lead to the generation of large quantities of waste products. As a consequence, there has been a considerable amount of interest in the development of new approaches to amide synthesis. Over the past few years a wide rang...

  7. Iodine-Catalyzed Decarboxylative Amidation of β,γ-Unsaturated Carboxylic Acids with Chloramine Salts Leading to Allylic Amides.

    Kiyokawa, Kensuke; Kojima, Takumi; Hishikawa, Yusuke; Minakata, Satoshi

    2015-10-26

    The iodine-catalyzed decarboxylative amidation of β,γ-unsaturated carboxylic acids with chloramine salts is described. This method enables the regioselective synthesis of allylic amides from various types of β,γ-unsaturated carboxylic acids containing substituents at the α- and β-positions. In the reaction, N-iodo-N-chloroamides, generated by the reaction of a chloramine salt with I2 , function as a key active species. The reaction provides an attractive alternative to existing methods for the synthesis of useful secondary allylic amine derivatives. PMID:26493878

  8. Lipase-catalyzed synthesis of fatty acid amide (erucamide) using fatty acid and urea.

    Awasthi, Neeraj Praphulla; Singh, R P

    2007-01-01

    Ammonolysis of fatty acids to the corresponding fatty acid amides is efficiently catalysed by Candida antartica lipase (Novozym 435). In the present paper lipase-catalysed synthesis of erucamide by ammonolysis of erucic acid and urea in organic solvent medium was studied and optimal conditions for fatty amides synthesis were established. In this process erucic acid gave 88.74 % pure erucamide after 48 hour and 250 rpm at 60 degrees C with 1:4 molar ratio of erucic acid and urea, the organic solvent media is 50 ml tert-butyl alcohol (2-methyl-2-propanol). This process for synthesis is economical as we used urea in place of ammonia or other amidation reactant at atmospheric pressure. The amount of catalyst used is 3 %. PMID:17898456

  9. Direct amidation of amino acid derivatives catalyzed by arylboronic acids : applications in dipeptide synthesis.

    Liu, S.; Yang, Y.; Liu, X.; Ferdousi, F. K.; Batsanov, A.S.; Whiting, A

    2013-01-01

    The direct amidation of amino acid derivatives catalyzed by arylboronic acids has been examined. The reaction was generally slow relative to simple amine-carboxylic acid combinations though proceeded at 65–68 °C generally avoiding racemization. 3,4,5-Trifluorophenylboronic and o-nitrophenylboronic acids were found to be the best catalysts, though for slower dipeptide formations, high catalyst loadings were required and an interesting synergistic catalytic effect between two arylboronic acids ...

  10. ISOLATION AND CHARACTERIZATION OF AN ACID, BILE SALT-INDEPENDENT, RETINYL ESTER HYDROLASE FROM RAT LIVER MICROSOMES

    Previous work in this laboratory has revealed the presence of both acidic and neutral bile-salt independent retinyl ester hydrolase activities in rat liver homogenates. Here we present the purification, identification and characterization of an acid retinyl ester hydrolase activity from solubilized ...

  11. Kynurenic acid amides as novel NR2B selective NMDA receptor antagonists.

    Borza, István; Kolok, Sándor; Galgóczy, Kornél; Gere, Anikó; Horváth, Csilla; Farkas, Sándor; Greiner, István; Domány, György

    2007-01-15

    A novel series of kynurenic acid amides, ring-enlarged derivatives of indole-2-carboxamides, was prepared and identified as in vivo active NR2B subtype selective NMDA receptor antagonists. The synthesis and SAR studies are discussed. PMID:17074483

  12. Peptidoglycan Hydrolases of Local Lactic Acid Bacteria from Kazakh Traditional Food

    Serik Shaikhin

    2014-01-01

    Full Text Available Introduction: Peptidoglycan (PG is a major component of the cell wall of Gram-positive bacteria and is essential for maintaining the integrity of the bacterial cell and its shape. The bacteria synthesize PG hydrolases, which are capable of cleaving the covalent bonds of PG. They also play an important role in modeling PG, which is required for bacterial growth and division. In an era of increasing antibiotic-resistant pathogens, PG hydrolases that destroy these important structures of the cell wall act as a potential source of new antimicrobials. The aim of this study is to identify the main PG hydrolases of local lactic acid bacteria isolated from traditional foods that enhance probiotic activity of a biological preparation. Methods. Lactococcus lactis 17А and Lactococcus garvieae 19А were isolated from the traditional sausage-like meat product called kazy. They were isolated according to standards methods of microbiology. Genetic identification of the isolates were tested by determining the nucleotide sequences of 16S rDNA. The Republican collection of microorganisms took strains of Lactobacillus casei subsp. Rhamnosus 13-P, L. delbrueckii subsp. lactis CG-1 B-RKM 0044 from cheese, Lactobacillus casei subsp. casei B-RKM 0202 from homemade butter. They used the standard technique of renaturating polyacrylamide gel electrophoresis to detect PG hydrolases activity. Results. According to the profiles of PG hydrolase activity on zymograms, the enzymes of Lactococci 17A and 19A in kazy are similar in electrophoretic mobility to major autolysin AcmA, while the lactobacilli of industrial and home-made dairy products have enzymes similar to extracellular proteins p40 and p75, which have probiotic activity. Conclusions. Use of peptidoglycan hydrolases seems to be an interesting approach in the fight against multi-drug resistant strains of bacteria and could be a valuable tool for the treatment of diseases caused by these microorganisms in Kazakhstan.

  13. Substituted Amides of Pyrazine-2-carboxylic acids: Synthesis and Biological Activity

    Katarina Kralova; Jiri Kunes; Miroslav Miletin; Martin Dolezal

    2002-01-01

    Condensation of 6-chloro-, 5-tert-butyl- or 6-chloro-5-tert-butylpyrazine-2-carboxylic acid chloride with ring substituted anilines yielded a series of amides, which were tested for their in vitro antimycobacterial, antifungal and photosynthesis-inhibiting activities. The highest antituberculotic activity (72% inhibition) against Mycobacterium tuberculosis and the highest lipophilicity (log P = 6.85) were shown by the 3,5-bistrifluoromethylphenyl amide of 5-tert-butyl-6-chloropyrazine-2-carbo...

  14. Syntheses of Macrocyclic Amides from L-Amino Acid Esters by RCM

    2007-01-01

    A series of succinate-derived macrocyclic amides( 1 ) was synthesized via ring-closing metathesis (RCM) as the key step. The substrate included 12 to 15 members. The metathesis precursors were obtained from the amide coupling of tert-butyl 3-carboxyhex-5-enoate(2) with numerous side-chain alkenylated amino acid esters of general type(3)derived from L-lysine and L-ornithine.

  15. Cell- and ligand-specific dephosphorylation of acid hydrolases: Evidence that the mannose 6-phosphatase is controlled by compartmentalization

    Einstein, R.; Gabel, C.A. (Columbia Univ. College of Physicians and Surgeons, NY (USA))

    1991-01-01

    Mouse L cells that possess the cation-independent mannose 6-phosphate (Man 6-P)/insulin-like growth factor (IGF) II receptor change the extent to which they dephosphorylate endocytosed acid hydrolases in response to serum. To investigate the mechanism by which dephosphorylation competence is regulated, the dephosphorylation of individual acid hydrolases was studied in Man 6-P/IGF II receptor-positive and -deficient cell lines. 125I-labeled Man 6-P-containing acid hydrolases were proteolytically processed but remained phosphorylated when endocytosed by receptor-positive L cells maintained in the absence of serum; after the addition of serum, however, the cell-associated hydrolases were dephosphorylated. Individual hydrolases were dephosphorylated at distinct rates and to different extents. In contrast, the same hydrolases were dephosphorylated equally and completely after entry into Man 6-P/IGF II receptor-positive Chinese hamster ovary (CHO) cells. The dephosphorylation competence of Man 6-P/IGF II receptor-deficient mouse J774 cells was more limited. beta-Glucuronidase produced by these cells underwent a limited dephosphorylation in transit to lysosomes such that diphosphorylated oligosaccharides were converted to monophosphorylated species. The overall quantity of phosphorylated oligosaccharides associated with the enzyme, however, did not decrease within the lysosomal compartment. Likewise, beta-glucuronidase was not dephosphorylated when introduced into J774 cells via Fc receptor-mediated endocytosis. The CHO and J774 cell lysosomes, therefore, display opposite extremes with respect to their capacity to dephosphorylate acid hydrolases; within CHO cell lysosomes acid hydrolases are rapidly and efficiently dephosphorylated, but within J774 cell lysosomes the same acid hydrolases remain phosphorylated.

  16. Cell- and ligand-specific dephosphorylation of acid hydrolases: Evidence that the mannose 6-phosphatase is controlled by compartmentalization

    Mouse L cells that possess the cation-independent mannose 6-phosphate (Man 6-P)/insulin-like growth factor (IGF) II receptor change the extent to which they dephosphorylate endocytosed acid hydrolases in response to serum. To investigate the mechanism by which dephosphorylation competence is regulated, the dephosphorylation of individual acid hydrolases was studied in Man 6-P/IGF II receptor-positive and -deficient cell lines. 125I-labeled Man 6-P-containing acid hydrolases were proteolytically processed but remained phosphorylated when endocytosed by receptor-positive L cells maintained in the absence of serum; after the addition of serum, however, the cell-associated hydrolases were dephosphorylated. Individual hydrolases were dephosphorylated at distinct rates and to different extents. In contrast, the same hydrolases were dephosphorylated equally and completely after entry into Man 6-P/IGF II receptor-positive Chinese hamster ovary (CHO) cells. The dephosphorylation competence of Man 6-P/IGF II receptor-deficient mouse J774 cells was more limited. beta-Glucuronidase produced by these cells underwent a limited dephosphorylation in transit to lysosomes such that diphosphorylated oligosaccharides were converted to monophosphorylated species. The overall quantity of phosphorylated oligosaccharides associated with the enzyme, however, did not decrease within the lysosomal compartment. Likewise, beta-glucuronidase was not dephosphorylated when introduced into J774 cells via Fc receptor-mediated endocytosis. The CHO and J774 cell lysosomes, therefore, display opposite extremes with respect to their capacity to dephosphorylate acid hydrolases; within CHO cell lysosomes acid hydrolases are rapidly and efficiently dephosphorylated, but within J774 cell lysosomes the same acid hydrolases remain phosphorylated

  17. Synthesis and effect of fatty acid amides as friction modifiers in petroleum base stock.

    Khalkar, Sharmishtha; Bhowmick, DiptiNarayan; Pratap, Amit

    2013-01-01

    Fatty acid amides were prepared by using Lewis acid as a catalyst. The products from reaction was subjected to solvent extraction with chloroform and then followed by purification with n-hexane, ethanol and acetonitrile. Fatty acid amide, characterized by various physicochemical and tribological properties like wear scar, weld load and coefficient of friction. These compounds found good antiwear (AW) and extreme pressure (EP) additive. The addition of various EP and AW additives in lubricating oil is an important and effective way to reduce friction and wear. Fatty acid amides were used as antiwear and friction modifier additive and a comparative study was carried out for 1%, 3%, 5% additive blend with commercial petroleum base stocks 150N and 500N. PMID:24200937

  18. Pharmaceuticals and Surfactants from Alga-Derived Feedstock: Amidation of Fatty Acids and Their Derivatives with Amino Alcohols.

    Tkacheva, Anastasia; Dosmagambetova, Inkar; Chapellier, Yann; Mäki-Arvela, Päivi; Hachemi, Imane; Savela, Risto; Leino, Reko; Viegas, Carolina; Kumar, Narendra; Eränen, Kari; Hemming, Jarl; Smeds, Annika; Murzin, Dmitry Yu

    2015-08-24

    Amidation of renewable feedstocks, such as fatty acids, esters, and Chlorella alga based biodiesel, was demonstrated with zeolites and mesoporous materials as catalysts and ethanolamine, alaninol, and leucinol. The last two can be derived from amino acids present in alga. The main products were fatty alkanol amides and the corresponding ester amines, as confirmed by NMR and IR spectroscopy. Thermal amidation of technical-grade oleic acid and stearic acid at 180 °C with ethanolamine were non-negligible; both gave 61% conversion. In the amidation of stearic acid with ethanolamine, the conversion over H-Beta-150 was 80% after 3 h, whereas only 63% conversion was achieved for oleic acid; this shows that a microporous catalyst is not suitable for this acid and exhibits a wrinkled conformation. The highest selectivity to stearoyl ethanolamide of 92% was achieved with mildly acidic H-MCM-41 at 70% conversion in 3 h at 180 °C. Highly acidic catalysts favored the formation of the ester amine, whereas the amide was obtained with a catalyst that exhibited an optimum acidity. The conversion levels achieved with different fatty acids in the range C12-C18 were similar; this shows that the fatty acid length does not affect the amidation rate. The amidation of methyl palmitate and biodiesel gave low conversions over an acidic catalyst, which suggested that the reaction mechanism in the amidation of esters was different. PMID:26197759

  19. Inhibition of epoxide hydrolase by valproic acid in epileptic patients receiving carbamazepine.

    Robbins, D K; Wedlund, P J; Kuhn, R.; Baumann, R J; Levy, R.H.; Chang, S.L.

    1990-01-01

    The effect of valproic acid (VPA) on the disposition of carbamazepine-10,11-epoxide (epoxide) was studied in five epileptic patients on chronic carbamazepine (CBZ) therapy. The individual pharmacokinetic parameters influencing epoxide disposition were determined in the presence and absence of VPA. VPA significantly decreased the clearance of unbound epoxide (an in vivo index of epoxide hydrolase activity), but did not appear to affect epoxide formation. VPA also increased the free concentrati...

  20. One pot direct synthesis of amides or oxazolines from carboxylic acids using Deoxo-Fluor reagent

    Kangani, Cyrous O.; Kelley, David E.

    2005-01-01

    A mild and highly efficient one pot–one step condensation and/or condensation–cyclization of various acids to amides and/or oxazolines using Deoxo-Fluor reagents is described. Parallel syntheses of various free fatty acids with 2-amino-2, 2-dimethyl-1-propanol resulted with excellent yields.

  1. New families in the classification of glycosyl hydrolases based on amino acid sequence similarities.

    Henrissat, B; Bairoch, A

    1993-01-01

    301 glycosyl hydrolases and related enzymes corresponding to 39 EC entries of the I.U.B. classification system have been classified into 35 families on the basis of amino-acid-sequence similarities [Henrissat (1991) Biochem. J. 280, 309-316]. Approximately half of the families were found to be monospecific (containing only one EC number), whereas the other half were found to be polyspecific (containing at least two EC numbers). A > 60% increase in sequence data for glycosyl hydrolases (181 additional enzymes or enzyme domains sequences have since become available) allowed us to update the classification not only by the addition of more members to already identified families, but also by the finding of ten new families. On the basis of a comparison of 482 sequences corresponding to 52 EC entries, 45 families, out of which 22 are polyspecific, can now be defined. This classification has been implemented in the SWISS-PROT protein sequence data bank. PMID:8352747

  2. Characterization of Two New Glycosyl Hydrolases from the Lactic Acid Bacterium Carnobacterium piscicola Strain BA

    Coombs, Jonna; Brenchley, Jean E.

    2001-01-01

    Three genes with homology to glycosyl hydrolases were detected on a DNA fragment cloned from a psychrophilic lactic acid bacterium isolate, Carnobacterium piscicola strain BA. A 2.2-kb region corresponding to an α-galactosidase gene, agaA, was followed by two genes in the same orientation, bgaB, encoding a 2-kb β-galactosidase, and bgaC, encoding a structurally distinct 1.76-kb β-galactosidase. This gene arrangement had not been observed in other lactic acid bacteria, including Lactococcus la...

  3. Gas-Phase Amidation of Carboxylic Acids with Woodward's Reagent K Ions

    Peng, Zhou; Pilo, Alice L.; Luongo, Carl A.; McLuckey, Scott A.

    2015-06-01

    Gas-phase amidation of carboxylic acids in multiply-charged peptides is demonstrated via ion/ion reactions with Woodward's reagent K (wrk) in both positive and negative mode. Woodward's reagent K, N-ethyl-3-phenylisoxazolium-3'-sulfonate, is a commonly used reagent that activates carboxylates to form amide bonds with amines in solution. Here, we demonstrate that the analogous gas-phase chemistry occurs upon reaction of the wrk ions and doubly protonated (or doubly deprotonated) peptide ions containing the carboxylic acid functionality. The reaction involves the formation of the enol ester intermediate in the electrostatic complex. Upon collisional activation, the ethyl amine on the reagent is transferred to the activated carbonyl carbon on the peptide, resulting in the formation of an ethyl amide (addition of 27 Da to the peptide) with loss of a neutral ketene derivative. Further collision-induced dissociation (CID) of the products and comparison with solution-phase amidation product confirms the structure of the ethyl amide.

  4. Molecular Basis of Prodrug Activation by Human Valacyclovirase, an [alpha]-Amino Acid Ester Hydrolase

    Lai, Longsheng; Xu, Zhaohui; Zhou, Jiahai; Lee, Kyung-Dall; Amidon, Gordon L. (Michigan)

    2008-07-08

    Chemical modification to improve biopharmaceutical properties, especially oral absorption and bioavailability, is a common strategy employed by pharmaceutical chemists. The approach often employs a simple structural modification and utilizes ubiquitous endogenous esterases as activation enzymes, although such enzymes are often unidentified. This report describes the crystal structure and specificity of a novel activating enzyme for valacyclovir and valganciclovir. Our structural insights show that human valacyclovirase has a unique binding mode and specificity for amino acid esters. Biochemical data demonstrate that the enzyme hydrolyzes esters of {alpha}-amino acids exclusively and displays a broad specificity spectrum for the aminoacyl moiety similar to tricorn-interacting aminopeptidase F1. Crystal structures of the enzyme, two mechanistic mutants, and a complex with a product analogue, when combined with biochemical analysis, reveal the key determinants for substrate recognition; that is, a flexible and mostly hydrophobic acyl pocket, a localized negative electrostatic potential, a large open leaving group-accommodating groove, and a pivotal acidic residue, Asp-123, after the nucleophile Ser-122. This is the first time that a residue immediately after the nucleophile has been found to have its side chain directed into the substrate binding pocket and play an essential role in substrate discrimination in serine hydrolases. These results as well as a phylogenetic analysis establish that the enzyme functions as a specific {alpha}-amino acid ester hydrolase. Valacyclovirase is a valuable target for amino acid ester prodrug-based oral drug delivery enhancement strategies.

  5. Human microsomal epoxide hydrolase: genetic polymorphism and functional expression in vitro of amino acid variants

    Hassett, Christopher; Aicher, Lauri; Sidhu, Jaspreet S.

    2016-01-01

    Human microsomal epoxide hydrolase (mEH) is a biotransformation enzyme that metabolizes reactive epoxide intermediates to more water-soluble trans-dihydrodiol derivatives. We compared protein-coding sequences from six full-length human mEH DNA clones and assessed potential amino acid variation at seven positions. The prevalence of these variants was assessed in at least 37 unrelated individuals using polymerase chain reaction experiments. Only Tyr/His 113 (exon 3) and His/Arg 139 (exon 4) variants were observed. The genotype frequencies determined for residue 113 alleles indicate that this locus may not be in Hardy – Weinberg equilibrium, whereas frequencies observed for residue 139 alleles were similar to expected values. Nucleotide sequences coding for the variant amino acids were constructed in an mEH cDNA using site-directed mutagenesis, and each was expressed in vitro by transient transfection of COS-1 cells. Epoxide hydrolase mRNA level, catalytic activity, and immunoreactive protein were evaluated for each construct. The results of these analyses demonstrated relatively uniform levels of mEH RNA expression between the constructs. mEH enzymatic activity and immunoreactive protein were strongly correlated, indicating that mEH specific activity was similar for each variant. However, marked differences were noted in the relative amounts of immunoreactive protein and enzymatic activity resulting from the amino acid substitutions. These data suggest that common human mEH amino acid polymorphisms may alter enzymatic function, possibly by modifying protein stability. PMID:7516776

  6. CUTICULAR LIPIDS OF THE STORED FOOD PEST, LIPOSCELIS BOSTRYCHOPHILA BADONNEL (PSOCOPTERA: LIPOSCELIDIDAE): HYDROCARBONS, ALDEHYDES, FATTY ACIDS AND FATTY ACID AMIDES

    The booklouse, Liposcelis bostrychophila, has increasingly become a common pest of stored food products worldwide. We report here the cuticular hydrocarbon composition of this pest (the first report of the hydrocarbons of any member of the Order Psocoptera) and the first report of fatty acid amides...

  7. Substituted Amides of Pyrazine-2-carboxylic acids: Synthesis and Biological Activity

    Katarina Kralova

    2002-03-01

    Full Text Available Condensation of 6-chloro-, 5-tert-butyl- or 6-chloro-5-tert-butylpyrazine-2-carboxylic acid chloride with ring substituted anilines yielded a series of amides, which were tested for their in vitro antimycobacterial, antifungal and photosynthesis-inhibiting activities. The highest antituberculotic activity (72% inhibition against Mycobacterium tuberculosis and the highest lipophilicity (log P = 6.85 were shown by the 3,5-bistrifluoromethylphenyl amide of 5-tert-butyl-6-chloropyrazine-2-carboxylic acid (2o. The 3-methylphenyl amides of 6-chloro- and 5-tert-butyl-6-chloro-pyrazine-2-carboxylic acid (2d and 2f exhibited only a poor in vitro antifungal effect (MIC = 31.25-500 μmol·dm-3 against all strains tested, although the latter was the most active antialgal compound (IC50 = 0.063 mmol·dm-3. The most active inhibitor of oxygen evolution rate in spinach chloroplasts was the (3,5-bis-trifluoromethylphenylamide of 6-chloropyrazine-2-carboxylic acid (2m, IC50 = 0.026 mmol·dm-3.

  8. Chiral amide from (1, 2)-(+)-norephedrine and furoic acid: An efficient catalyst for asymmetric Reformatsky reaction

    Nallamuthu Ananthi; Sivan Velmathi

    2014-01-01

    Chiral amide derived from (1, 2)-(+)-norephedrine and 2-furoic acid was found to catalyse the asymmetric Reformatsky reaction between prochiral aldehydes and α-bromo ethylacetate with diethylzinc as zinc source. The corresponding chiral -hydroxy esters were formed in 99% yield with over 80% enantiomeric excess. The presence of air was found to be essential for the effective C-C bond formation. The mechanism for the catalytic reaction was proposed.

  9. Synthesis and Properties of Lactic Acid-based Cross-linked Poly(ester-amide)

    Yue Ying HE; Cong Ming XIAO

    2006-01-01

    A novel lactic acid-based cross-linked poly(ester-amide) (LCPEA) was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties of the LCPEA. The tensile strength, elastic modulus and bend strength of the LCPEA of 65% gel fraction were 4.65, 136.55 and 39.63 MPa, respectively. The thermal decomposition temperature (50 wt%) of the LCPEA was around 410 ℃.

  10. Purification and characterization of a cis-epoxysuccinic acid hydrolase from Nocardia tartaricans CAS-52, and expression in Escherichia coli.

    Wang, Ziqiang; Wang, Yunshan; Su, Zhiguo

    2013-03-01

    A highly enantioselective cis-epoxysuccinic acid hydrolase from Nocardia tartaricans was purified to electrophoretic homogeneity. The enzyme was purified 184-fold with a yield of 18.8 %. The purified cis-epoxysuccinic acid hydrolase had a monomeric molecular weight of 28 kDa, and its optimum conditions were 37 °C and pH 7-9. With sodium cis-epoxysuccinate as the substrate, Michaelis-Menten enzyme kinetics analysis gave a Km value of 35.71 mM and a Vmax of 2.65 mM min(-1). The enzyme was activated by Ni(2+) and Al(3+), while strongly inhibited by Fe(3+), Fe(2+), Cu(2+), and Ag(+). The cis-epoxysuccinic acid hydrolase gene was cloned, and its open reading frame sequence predicted a protein composed of 253 amino acids. A pET11a expression plasmid carrying the gene under the control of the T7 promoter was introduced into Escherichia coli, and the cis-epoxysuccinic acid hydrolase gene was successfully expressed in the recombinant strains. PMID:22552902

  11. MATE Transporter-Dependent Export of Hydroxycinnamic Acid Amides[OPEN

    Eschen-Lippold, Lennart; Gorzolka, Karin; Matern, Andreas; Marillonnet, Sylvestre; Böttcher, Christoph; Rosahl, Sabine

    2016-01-01

    The ability of Arabidopsis thaliana to successfully prevent colonization by Phytophthora infestans, the causal agent of late blight disease of potato (Solanum tuberosum), depends on multilayered defense responses. To address the role of surface-localized secondary metabolites for entry control, droplets of a P. infestans zoospore suspension, incubated on Arabidopsis leaves, were subjected to untargeted metabolite profiling. The hydroxycinnamic acid amide coumaroylagmatine was among the metabolites secreted into the inoculum. In vitro assays revealed an inhibitory activity of coumaroylagmatine on P. infestans spore germination. Mutant analyses suggested a requirement of the p-coumaroyl-CoA:agmatine N4-p-coumaroyl transferase ACT for the biosynthesis and of the MATE transporter DTX18 for the extracellular accumulation of coumaroylagmatine. The host plant potato is not able to efficiently secrete coumaroylagmatine. This inability is overcome in transgenic potato plants expressing the two Arabidopsis genes ACT and DTX18. These plants secrete agmatine and putrescine conjugates to high levels, indicating that DTX18 is a hydroxycinnamic acid amide transporter with a distinct specificity. The export of hydroxycinnamic acid amides correlates with a decreased ability of P. infestans spores to germinate, suggesting a contribution of secreted antimicrobial compounds to pathogen defense at the leaf surface. PMID:26744218

  12. Partial purification and characterization of an inducible indole-3-acetyl-L-aspartic acid hydrolase from Enterobacter agglomerans

    Chou, Jyh-Ching [Department of Agriculture, Beltsville, MD (United States)]|[Univ. of Maryland, College Park, MD (United States); Cohen, J.D.; Mulbry, W.W. [Department of Agriculture, Beltsville, MD (United States)] [and others

    1996-11-01

    Indole-3-acetyl-amino acid conjugate hydrolases are believed to be important in the regulation of indole-3-acetic acid (IAA) metabolism in plants and therefore have potential uses for the alteration of plant IAA metabolism. To isolate bacterial strains exhibiting significant indole-3-acetyl-aspartate (IAA-Asp) hydrolase activity, a sewage sludge inoculation was cultured under conditions in which IAA-Asp served as the sole source of carbon and nitrogen. One isolate, Enterobacter agglomerans, showed hydrolase activity inducible by IAA-L-Asp or N-acetyl-L-Asp but not by IAA, (NH{sub 4}){sub 2}SO{sub 4}, urea, or indoleacetamide. Among a total of 17 IAA conjugates tested as potential substrates, the enzyme had an exclusively high substrate specificity for IAA-L-Asp of 13.5 mM. The optimal pH for this enzyme was between 8.0 and 8.5. In extraction buffer containing 0.8 mM Mg{sup 2+} the hydrolase activity was inhibited to 80% by 1 mM dithiothreitol and to 60% by 1 mm CuSO{sub 4}; the activity was increased by 40% with 1mM MnSO{sub 4}. However, in extraction buffer with no trace elements, the hydrolase activity was inhibited to 50% by either 1 mM dithiothreitol or 1% Triton X-100 (Sigma). These results suggest that disulfide bonding might be essential for enzyme activity. Purification of the hydrolase by hydroxyapatite and TSK-phenyl (HP-Genenchem, South San Francisco, CA) preparative high-performance liquid chromatography yielded a major 45-kD polypeptide as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 45 refs., 5 figs., 3 tabs.

  13. Regiospecific tritium labeling of aromatic acids, amides, amines and heterocyclics using homogeneous rhodium trichloride and ruthenium acetylacetonate catalysts

    Homogeneous rhodium trichloride has been found to promote ortho-tritiation with high regioselectivity in a wide range of aromatic carboxylic acids, amides and aralkylamines. Less successful results were obtained using o-chlorobenzoic and o-anisic acids where some decomposition was seen, and in acids and amides of the phenolic type, where a degree of electrophilic exchange accompanies the ortho-exchange. The same catalyst has also been used to regiospecifically label a number of heterocyclics. In the course of investigations with other metal complexes ruthenium acetylacetonate has been identified as an excellent promoter of ortho-exchange in benzoic acids. (author)

  14. Synthesis, Anti-HCV, Antioxidant and Reduction of Intracellular Reactive Oxygen Species Generation of a Chlorogenic Acid Analogue with an Amide Bond Replacing the Ester Bond

    Ling-Na Wang

    2016-06-01

    Full Text Available Chlorogenic acid is a well known natural product with important bioactivities. It contains an ester bond formed between the COOH of caffeic acid and the 3-OH of quinic acid. We synthesized a chlorogenic acid analogue, 3α-caffeoylquinic acid amide, using caffeic and quinic acids as starting materials. The caffeoylquinc acid amide was found to be much more stable than chlorogenic acid and showed anti-Hepatitis C virus (anti-HCV activity with a potency similar to chlorogenic acid. The caffeoylquinc acid amide potently protected HepG2 cells against oxidative stress induced by tert-butyl hydroperoxide.

  15. Visible-Light-Mediated Synthesis of Amides from Aldehydes and Amines via in Situ Acid Chloride Formation.

    Iqbal, Naeem; Cho, Eun Jin

    2016-03-01

    An efficient visible-light photocatalysis-based one-pot amide synthesis method was developed; visible-light irradiation of a mixture of an aldehyde, tert-butyl hydrogen peroxide, and N-chlorosuccinimide using a Ru(bpy)3Cl2 photocatalyst afforded an acid chloride, which subsequently reacted with amine to yield the corresponding amide. The reaction was used to synthesize moclobemide and a D3 receptor intermediate. PMID:26836367

  16. Fatty acid amide supplementation decreases impulsivity in young adult heavy drinkers.

    van Kooten, Maria J; Veldhuizen, Maria G; de Araujo, Ivan E; O'Malley, Stephanie S; Small, Dana M

    2016-03-01

    Compromised dopamine signaling in the striatum has been associated with the expression of impulsive behaviors in addiction, obesity and alcoholism. In rodents, intragastric infusion of the fatty acid amide oleoylethanolamide increases striatal extracellular dopamine levels via vagal afferent signaling. Here we tested whether supplementation with PhosphoLean™, a dietary supplement that contains the precursor of the fatty acid amide oleoylethanolamide (N-oleyl-phosphatidylethanolamine), would reduce impulsive responding and alcohol use in heavy drinking young adults. Twenty-two individuals were assigned to a three-week supplementation regimen with PhosphoLean™ or placebo. Impulsivity was assessed with self-report questionnaires and behavioral tasks pre- and post-supplementation. Although self-report measures of impulsivity did not change, supplementation with PhosphoLean™, but not placebo, significantly reduced false alarm rate on a Go/No-Go task. In addition, an association was found between improved sensitivity on the Go/No-Go task and reduced alcohol intake. These findings provide preliminary evidence that promoting fatty acid derived gut-brain dopamine communication may have therapeutic potential for reducing impulsivity in heavy drinkers. PMID:26656766

  17. Amide functionalized Calix-Benzocrown-6 ionophore for extraction of cesium from highly concentrated nitric acid medium

    A series of novel calix(4)arene-benzocrown-6 amide (CBCA) ligands in 1,3-alternate conformations with amidic group attached to aromatic ring of the polyether ring network have been synthesised and evaluated for extraction of caesium from nitric acid medium (1-10M). Isodecyl alcohol (IDA) and o-nitrophenyl hexyl ether (o-NPHE) modified calix/dodecane have been used for extraction studies. The extraction of Cs increases with nitric acid concentration, the maxima is obtained at ∼ 4.5M for calix-benzo-crown-6 (CBC) used as standard, whereas, in case of CBCA this maxima reaches to ∼ 8M nitric acid concentration. This difference is attributed to neutralization of nitric acid by intramolecular buffering effect of amidic group of CBCA. (author)

  18. Electrostatic interaction of pi-acidic amides with hydrogen-bond acceptors.

    Li, Yi; Snyder, Lawrence B; Langley, David R

    2003-10-01

    Interactions between N-methylacetamide (NMA) and N-methylated derivatives of uracil, isocyanurate and barbituric acid have been studied using ab initio methods at the local MP2/6-31G** level of theory. The results were compared to similar interactions between the oxygen atom of NMA and the pi-clouds of perfluorobenzene, quinone and trimethyltriazine. The pi-acidic amides of isocyanurate and barbituric acid were found to interact with a hydrogen bond acceptor primarily through electrostatic attractions. These groups may be used as alternatives of a hydrogen bond donor to complement a hydrogen bond acceptor or an anion in molecular recognition and drug design. Examples of such interactions were identified through a search of the CSD database. PMID:12951105

  19. Isolation, identification and quantification of unsaturated fatty acids, amides, phenolic compounds and glycoalkaloids from potato peel.

    Wu, Zhi-Gang; Xu, Hai-Yan; Ma, Qiong; Cao, Ye; Ma, Jian-Nan; Ma, Chao-Mei

    2012-12-15

    Eleven compounds were isolated from potato peels and identified. Their structures were determined by interpretation of UV, MS, 1D, and 2D NMR spectral data and by comparison with reported data. The main components of the potato peels were found to be chlorogenic acid and other phenolic compounds, accompanied by 2 glycoalkaloids, 3 low-molecular-weight amide compounds, and 2 unsaturated fatty acids, including an omega-3 fatty acid. The potato peels showed more potent radical scavenging activity than the flesh. The quantification of the 11 components indicated that the potato peels contained a higher amount of phenolic compounds than the flesh. These results suggest that peel waste from the industry of potato chips and fries may be a source of useful compounds for human health. PMID:22980823

  20. Cinnamic acid amides from Tribulus terrestris displaying uncompetitive α-glucosidase inhibition.

    Song, Yeong Hun; Kim, Dae Wook; Curtis-Long, Marcus J; Park, Chanin; Son, Minky; Kim, Jeong Yoon; Yuk, Heung Joo; Lee, Keun Woo; Park, Ki Hun

    2016-05-23

    The α-glucosidase inhibitory potential of Tribulus terrestris extracts has been reported but as yet the active ingredients are unknown. This study attempted to isolate the responsible metabolites and elucidate their inhibition mechanism of α-glucosidase. By fractionating T. terristris extracts, three cinnamic acid amide derivatives (1-3) were ascertained to be active components against α-glucosidase. The lead structure, N-trans-coumaroyltyramine 1, showed significant inhibition of α-glucosidase (IC50 = 0.42 μM). Moreover, all active compounds displayed uncompetitive inhibition mechanisms that have rarely been reported for α-glucosidase inhibitors. This kinetic behavior was fully demonstrated by showing a decrease of both Km and Vmax, and Kik/Kiv ratio ranging between 1.029 and 1.053. We progressed to study how chemical modifications to the lead structure 1 may impact inhibition. An α, β-unsaturation carbonyl group and hydroxyl group in A-ring of cinnamic acid amide emerged to be critical functionalities for α-glucosidase inhibition. The molecular modeling study revealed that the inhibitory activities are tightly related to π-π interaction as well as hydrogen bond interaction between enzyme and inhibitors. PMID:26974386

  1. The effect of pH on the toxicity of fatty acids and fatty acid amides to rainbow trout gill cells.

    Bertin, Matthew J; Voronca, Delia C; Chapman, Robert W; Moeller, Peter D R

    2014-01-01

    Harmful algal blooms (HABs) expose aquatic organisms to multiple physical and chemical stressors during an acute time period. Algal toxins themselves may be altered by water chemistry parameters affecting their bioavailability and resultant toxicity. The purpose of this study was to determine the effects of two abiotic parameters (pH, inorganic metal salts) on the toxicity of fatty acid amides and fatty acids, two classes of lipids produced by harmful algae, including the golden alga, Prymnesium parvum, that are toxic to aquatic organisms. Rainbow trout gill cells were used as a model of the fish gill and exposed to single compounds and mixtures of compounds along with variations in pH level and concentration of inorganic metal salts. We employed artificial neural networks (ANNs) and standard ANOVA statistical analysis to examine and predict the effects of these abiotic parameters on the toxicity of fatty acid amides and fatty acids. Our results demonstrate that increasing pH levels increases the toxicity of fatty acid amides and inhibits the toxicity of fatty acids. This phenomenon is reversed at lower pH levels. Exposing gill cells to complex mixtures of chemical factors resulted in dramatic increases in toxicity compared to tests of single compounds for both the fatty acid amides and fatty acids. These findings highlight the potential of physicochemical factors to affect the toxicity of chemicals released during algal blooms and demonstrate drastic differences in the effect of pH on fatty acid amides and fatty acids. PMID:24240104

  2. CO2 Solubilities in Amide-based Brφnsted Acidic Ionic Liquids

    A distinguished class of hydrophobic ionic liquids bearing a Brφnsted acidic character derived from amide-like compounds were prepared by a neutralization reaction of N,N-diethylformamide, N,N-dibutylformamide, 1-formylpiperidine, and ε-caprolactam with trifluoroacetic acid and physical absorptions of CO2 in these ionic liquids were demonstrated and evaluated. CO2 solubilities in these ionic liquids were influenced by the molecular structure of the cation and were apparently increased with the molar volume. Comparison based on a volume unit reveals that CO2 solubilities in these liquids are relatively higher than those in imidazolium-based ionic liquids. Henry's coefficients calculated from low-pressure solubility tests at 313 to 333 K were used to derive the thermodynamics quantities. Enthalpy and entropy of solvation may share equal contributions in solubility

  3. Synthesis and Antimicrobial Activities of Amides of Chiral Benzyl Ethers of N-Boc Protected Aminols of L-amino acids with Succinic Acid

    The research work presented in this article describes a synthesis of chiral amides. Chiral benzyl ethers of N-Boc protected aminols reacted with succinic acid using 2,4,6-trichloro-1,3,5-triazine (TCT) as a coupling agent producing chiral amides in high yields. The synthetic amides were investigated for their antifungal and antibacterial activities against different bacterial and fungal strains. All the compounds showed excellent zone of inhibition against the three tested bacterial strains and good to moderate activity against one fungal strain. (author)

  4. Solubility of CO2 in amide-based Brønsted acidic ionic liquids

    Highlights: ► The CO2 solubility in Brønsted acidic ionic liquids (BAIL) has been reported. ► The experimental data were reduced to Henry’s law constants as a function of temperature. ► The Gibbs free energy, enthalpy and entropy changes were calculated. ► Relationship between solubility and molar volumes of BAILs was developed. - Abstract: Several hydrophilic amide-based Brønsted acidic ionic liquids (BAILs) were prepared by simple acid-base neutralization reaction of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methylpyrrolidone (NMP) with trifluoroacetic acid (TFA) or tetrafluoroboric acid (FBA). The solubility data of CO2 in these BAILs were determined at T = (303.15, 313.15, and 323.15) K and subatmospheric pressure using isochoric saturation method. With the same cation, CO2 solubility in TFA-based BAILs was higher than that in FBA-based ones. From the variation of solubility, expressed as Henry’s law constants, with temperature, the standard Gibbs free energy, enthalpy, and entropy changes of CO2 solvation were calculated. The solubilities of CO2 in these BAILs were apparently increased with increasing the molar volume of BAIL except for [DMFH][TFA].

  5. Development of the aza-crown ether metal complexes as artificial hydrolase.

    Yu, Lan; Li, Fang-zhen; Wu, Jiao-yi; Xie, Jia-qing; Li, Shuo

    2016-01-01

    Hydrolases play a crucial role in the biochemical process, which can catalyze the hydrolysis of various compounds like carboxylic esters, phosphoesters, amides, nucleic acids, peptides, and so on. The design of artificial hydrolases has attracted extensive attention due to their scientific significance and potential applications in the field of gene medicine and molecular biology. Numerous macrocyclic metal complexes have been used as artificial hydrolase in the catalytic hydrolysis of the organic substrate. Aza-crown ether for this comment is a special class of the macrocyclic ligand containing both the nitrogen atoms and oxygen atoms in the ring. The studies showed that the aza-crown complexes exhibited high activity of hydrolytic enzyme. However, the aza-crown ether metal complex as artificial hydrolase is still very limited because of its difficulty in synthesis. This review summarizes the development of the aza-crown ether metal complexes as the artificial hydrolase, including the synthesis and catalysis of the transition metal complexes and lanthanide metal complexes of aza-crown ethers. The purpose of this review is to highlight: (1) the relationship between the structure and hydrolytic activity of synthetic hydrolase; (2) the synergistic effect of metal sites and ligands in the course of organic compound hydrolysis; and (3) the design strategies of the aza-crown ethers as hydrolase. PMID:26460062

  6. Complexes of rare-earth perchlorates with ditbutyl amides of di, tri and tetraglycolic acids

    Premlatha, C; Soundararajan, S

    1981-01-01

    New complexes of lanthanide perchlorates with di-t-butyl amides of di, tri and tetraglycolic acids have been synthesised. The complexes have the general formula Ln(DiGA)3(ClO4)3; Ln(TriGA)2 (ClO4)3 and Ln(TetGA)2 (C1O4)3, where Ln = La-Yb and Y and DiGA = N,N′, di-t-butyl diglycolamide, TriGA N,N′, di-t-butyl triglycolamide and TetGA = N,N′ di-t-butyl tetraglycolamide, respectively. The complexes have been characterized by analysis, electrolytic conductance, infrared,1H and13C nuclear magneti...

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

    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. PMID:27503686

  8. Atom-economic catalytic amide synthesis from amines and carboxylic acids activated in situ with acetylenes

    Krause, Thilo; Baader, Sabrina; Erb, Benjamin; Gooßen, Lukas J.

    2016-01-01

    Amide bond-forming reactions are of tremendous significance in synthetic chemistry. Methodological research has, in the past, focused on efficiency and selectivity, and these have reached impressive levels. However, the unacceptable amounts of waste produced have led the ACS GCI Roundtable to label ‘amide bond formation avoiding poor atom economy' as the most pressing target for sustainable synthetic method development. In response to this acute demand, we herein disclose an efficient one-pot amide coupling protocol that is based on simple alkynes as coupling reagents: in the presence of a dichloro[(2,6,10-dodecatriene)-1,12-diyl]ruthenium catalyst, carboxylate salts of primary or secondary amines react with acetylene or ethoxyacetylene to vinyl ester intermediates, which undergo aminolysis to give the corresponding amides along only with volatile acetaldehyde or ethyl acetate, respectively. The new amide synthesis is broadly applicable to the synthesis of structurally diverse amides, including dipeptides. PMID:27282773

  9. Atom-economic catalytic amide synthesis from amines and carboxylic acids activated in situ with acetylenes.

    Krause, Thilo; Baader, Sabrina; Erb, Benjamin; Gooßen, Lukas J

    2016-01-01

    Amide bond-forming reactions are of tremendous significance in synthetic chemistry. Methodological research has, in the past, focused on efficiency and selectivity, and these have reached impressive levels. However, the unacceptable amounts of waste produced have led the ACS GCI Roundtable to label 'amide bond formation avoiding poor atom economy' as the most pressing target for sustainable synthetic method development. In response to this acute demand, we herein disclose an efficient one-pot amide coupling protocol that is based on simple alkynes as coupling reagents: in the presence of a dichloro[(2,6,10-dodecatriene)-1,12-diyl]ruthenium catalyst, carboxylate salts of primary or secondary amines react with acetylene or ethoxyacetylene to vinyl ester intermediates, which undergo aminolysis to give the corresponding amides along only with volatile acetaldehyde or ethyl acetate, respectively. The new amide synthesis is broadly applicable to the synthesis of structurally diverse amides, including dipeptides. PMID:27282773

  10. Improved annotation of conjugated bile acid hydrolase superfamily members in Gram-positive bacteria

    Lambert, J.M.; Siezen, R.J.; Vos, de W.M.; Kleerebezem, M.

    2008-01-01

    Most Gram-positive bacteria inhabiting the gastrointestinal tract are capable of hydrolysing bile salts. Bile salt hydrolysis is thought to play an important role in various biological processes in the host. Therefore, correct annotation of bacterial bile salt hydrolases (Bsh) in public databases (E

  11. The extraction of uranium (VI) and plutonium (IV) from nitric acid solutions with N,N-dialkyl substituting amides

    The use of N,N-di-2-methylheptyl acetamide (DMHAA),N,N-di-butylbutylamide(DBBA) and N,N-di-butylheptylamide(DBHA) as extractants for the extraction of nitric acid, U(VI) and Pu(IV) from the nitric acid solution has been investigated. The molar ratios of DBHA-HNO3 and DBHA-UO2(NO3)2 complexes are found to be 1:1 and 2:1 respectively. The complexes of both nitric acid and uranyl nitrate with these amides are highly soluble in aromatic diluent such as toluene without any formation of the third phase. The results show that, by modifying the length of the substitute chain and the degree of branch chain, some substituted amides might be found with which U(VI) and Pu(IV) could be co-extracted at moderate nitric acid solution and Pu(IV) could be preferably stripped at low acidity, and the separation of U(VI) and Pu(IV) could be accomplished without reductant of U(VI) and Pu(IV) in amide extraction

  12. Pd-Catalyzed Coupling of γ-C(sp(3))-H Bonds of Oxalyl Amide-Protected Amino Acids with Heteroaryl and Aryl Iodides.

    Han, Jian; Zheng, Yongxiang; Wang, Chao; Zhu, Yan; Huang, Zhi-Bin; Shi, Da-Qing; Zeng, Runsheng; Zhao, Yingsheng

    2016-07-01

    Pd-catalyzed regioselective coupling of γ-C(sp(3))-H bonds of oxalyl amide-protected amino acids with heteroaryl and aryl iodides is reported. A wide variety of iodides are tolerated, giving the corresponding products in moderate to good yields. Various oxalyl amide-protected amino acids were compatible in this C-H transformation, thus representing a practical method for constructing non-natural amino acid derivatives. PMID:27286881

  13. Fatty Acid Amide Hydrolase-Dependent Generation of Antinociceptive Drug Metabolites Acting on TRPV1 in the Brain

    Barriere, David A.; Mallet, Christophe; Blomgren, Anders; Simonsen, Charlotte; Daulhac, Laurence; Libert, Frederic; Chapuy, Eric; Etienne, Monique; Högestätt, Edward; Zygmunt, Peter; Eschalier, Alain

    2013-01-01

    The discovery that paracetamol is metabolized to the potent TRPV1 activator N-(4-hydroxyphenyl)-5Z, 8Z, 11Z, 14Z-eicosatetraenamide (AM404) and that this metabolite contributes to paracetamol's antinociceptive effect in rodents via activation of TRPV1 in the central nervous system (CNS) has provided a potential strategy for developing novel analgesics. Here we validated this strategy by examining the metabolism and antinociceptive activity of the de-acetylated paracetamol metabolite 4-ami...

  14. Synthesis and structure-activity relationship of piperidine-derived non-urea soluble epoxide hydrolase inhibitors

    Pecic, Stevan; Pakhomova, Svetlana; Newcomer, Marcia E.; Morisseau, Christophe; Hammock, Bruce D.; Zhu, Zhengxiang; Rinderspacher, Alison; Deng, Shi-Xian [UCD; (LSU); (Columbia)

    2013-09-27

    A series of potent amide non-urea inhibitors of soluble epoxide hydrolase (sEH) is disclosed. The inhibition of soluble epoxide hydrolase leads to elevated levels of epoxyeicosatrienoic acids (EETs), and thus inhibitors of sEH represent one of a novel approach to the development of vasodilatory and anti-inflammatory drugs. Structure–activities studies guided optimization of a lead compound, identified through high-throughput screening, gave rise to sub-nanomolar inhibitors of human sEH with stability in human liver microsomal assay suitable for preclinical development.

  15. Synthesis of novel nanostructured chiral poly(amide-imide)s containing dopamine and natural amino acids

    Shadpour Mallakpour; Amin Zadehnazari

    2013-01-01

    Four new thermally stable and optically active poly(amide-imide)s (PAI)s with good inherent viscosities were synthesized from the direct polycondensation reaction of N,N'-(pyromellitoyl)-bis-L--amino acids with 3,5-diamino-N-(3,4-dihydroxy-phen-ethyl)benzamide in a medium consisting of a molten salt, tetrabutylammonium bromide, and triphenyl phosphite as the activator. The polymerization reactions produced a series of novel PAIs containing dopamine segment in the side chain in high yield with inherent viscosities between 0.33 and 0.49 dL/g. The obtained polymers were typically characterized by means of FT-IR, 1HNMR spectroscopy, elemental analyses, powder X-ray diffraction, field emission scanning electronmicroscopy, inherent viscosity, and solubility tests. Thermal properties and flame retardant behaviour of the PAIs were also investigated using thermal gravimetric analysis (TGA and DTG) and limiting oxygen index (LOI). Data obtained by thermal analysis revealed that these polymers showed good thermal stability. Furthermore, high char yield in TGA and good LOI values indicated that the obtained polymers were capable of exhibiting good flame retardant properties.

  16. Synthesis, Antifungal Activity and QSAR of Some Novel Carboxylic Acid Amides

    Shijie Du

    2015-03-01

    Full Text Available A series of novel aromatic carboxylic acid amides were synthesized and tested for their activities against six phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to good activity. Among them N-(2-(1H-indazol-1-ylphenyl-2-(trifluoromethylbenzamide (3c exhibited the highest antifungal activity against Pythium aphanidermatum (EC50 = 16.75 µg/mL and Rhizoctonia solani (EC50 = 19.19 µg/mL, compared to the reference compound boscalid with EC50 values of 10.68 and 14.47 µg/mL, respectively. Comparative molecular field analysis (CoMFA and comparative molecular similarity indices analysis (CoMSIA were employed to develop a three-dimensional quantitative structure-activity relationship model for the activity of the compounds. In the molecular docking, a fluorine atom and the carbonyl oxygen atom of 3c formed hydrogen bonds toward the hydroxyl hydrogens of TYR58 and TRP173.

  17. Characterization of an Indole-3-Acetamide Hydrolase from Alcaligenes faecalis subsp. parafaecalis and Its Application in Efficient Preparation of Both Enantiomers of Chiral Building Block 2,3-Dihydro-1,4-Benzodioxin-2-Carboxylic Acid.

    Pradeep Mishra

    Full Text Available Both the enantiomers of 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid are valuable chiral synthons for enantiospecific synthesis of therapeutic agents such as (S-doxazosin mesylate, WB 4101, MKC 242, 2,3-dihydro-2-hydroxymethyl-1,4-benzodioxin, and N-[2,4-oxo-1,3-thiazolidin-3-yl]-2,3-dihydro-1,4-benzodioxin-2-carboxamide. Pharmaceutical applications require these enantiomers in optically pure form. However, currently available methods suffer from one drawback or other, such as low efficiency, uncommon and not so easily accessible chiral resolving agent and less than optimal enantiomeric purity. Our interest in finding a biocatalyst for efficient production of enantiomerically pure 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid lead us to discover an amidase activity from Alcaligenes faecalis subsp. parafaecalis, which was able to kinetically resolve 2,3-dihydro-1,4-benzodioxin-2-carboxyamide with E value of >200. Thus, at about 50% conversion, (R-2,3-dihydro-1,4-benzodioxin-2-carboxylic acid was produced in >99% e.e. The remaining amide had (S-configuration and 99% e.e. The amide and acid were easily separated by aqueous (alkaline-organic two phase extraction method. The same amidase was able to catalyse, albeit at much lower rate the hydrolysis of (S-amide to (S-acid without loss of e.e. The amidase activity was identified as indole-3-acetamide hydrolase (IaaH. IaaH is known to catalyse conversion of indole-3-acetamide (IAM to indole-3-acetic acid (IAA, which is phytohormone of auxin class and is widespread among plants and bacteria that inhabit plant rhizosphere. IaaH exhibited high activity for 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which was about 65% compared to its natural substrate, indole-3-acetamide. The natural substrate for IaaH indole-3-acetamide shared, at least in part a similar bicyclic structure with 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which may account for high activity of enzyme towards this un-natural substrate. To

  18. Characterization of an Indole-3-Acetamide Hydrolase from Alcaligenes faecalis subsp. parafaecalis and Its Application in Efficient Preparation of Both Enantiomers of Chiral Building Block 2,3-Dihydro-1,4-Benzodioxin-2-Carboxylic Acid.

    Mishra, Pradeep; Kaur, Suneet; Sharma, Amar Nath; Jolly, Ravinder S

    2016-01-01

    Both the enantiomers of 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid are valuable chiral synthons for enantiospecific synthesis of therapeutic agents such as (S)-doxazosin mesylate, WB 4101, MKC 242, 2,3-dihydro-2-hydroxymethyl-1,4-benzodioxin, and N-[2,4-oxo-1,3-thiazolidin-3-yl]-2,3-dihydro-1,4-benzodioxin-2-carboxamide. Pharmaceutical applications require these enantiomers in optically pure form. However, currently available methods suffer from one drawback or other, such as low efficiency, uncommon and not so easily accessible chiral resolving agent and less than optimal enantiomeric purity. Our interest in finding a biocatalyst for efficient production of enantiomerically pure 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid lead us to discover an amidase activity from Alcaligenes faecalis subsp. parafaecalis, which was able to kinetically resolve 2,3-dihydro-1,4-benzodioxin-2-carboxyamide with E value of >200. Thus, at about 50% conversion, (R)-2,3-dihydro-1,4-benzodioxin-2-carboxylic acid was produced in >99% e.e. The remaining amide had (S)-configuration and 99% e.e. The amide and acid were easily separated by aqueous (alkaline)-organic two phase extraction method. The same amidase was able to catalyse, albeit at much lower rate the hydrolysis of (S)-amide to (S)-acid without loss of e.e. The amidase activity was identified as indole-3-acetamide hydrolase (IaaH). IaaH is known to catalyse conversion of indole-3-acetamide (IAM) to indole-3-acetic acid (IAA), which is phytohormone of auxin class and is widespread among plants and bacteria that inhabit plant rhizosphere. IaaH exhibited high activity for 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which was about 65% compared to its natural substrate, indole-3-acetamide. The natural substrate for IaaH indole-3-acetamide shared, at least in part a similar bicyclic structure with 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which may account for high activity of enzyme towards this un-natural substrate. To the best of

  19. Evaluation of unsaturated alkanoic acid amides as maskers of epigallocatechin gallate astringency.

    Obst, Katja; Paetz, Susanne; Backes, Michael; Reichelt, Katharina V; Ley, Jakob P; Engel, Karl-Heinz

    2013-05-01

    Some foods, beverages, and food ingredients show characteristic long-lasting aftertastes. The sweet, lingering taste of high intensity sweeteners or the astringency of tea catechins are typical examples. Epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, causes a long-lasting astringency and bitterness. These sensations are mostly perceived as aversive and are only accepted in a few foods (e.g., tea and red wine). For the evaluation of the aftertaste of such constituents over a certain period of time, Intensity Variation Descriptive Methodology (IVDM) was used. The approach allows the measurement of different descriptors in parallel in one panel session. IVDM was evaluated concerning the inter- and intraindividual differences of panelists for bitterness and astringency of EGCG. Subsequently, the test method was used as a screening tool for the identification of potential modality-selective masking compounds. In particular, the intensity of the astringency of EGCG (750 mg kg(-1)) could be significantly lowered by 18-33% during the time course by adding the trigeminal-active compound trans-pellitorine (2E,4E-decadienoic acid N-isobutyl amide 1, 5 mg kg(-1)) without significantly affecting bitterness perception. Further, structurally related compounds were evaluated on EGCG to gain evidence for possible structure-activity relationships. A more polar derivative of 1, (2S)-2-[[(2E,4E)-deca-2,4-dienoyl]amino]propanoic acid 9, was also able to reduce the astringency of EGCG similar to trans-pellitorine but without showing the strong tingling effect. PMID:23582039

  20. Synthesis and structural studies of amino amide salts derived from 2-(aminomethyl)benzimidazole and α-amino acids

    Avila-Montiel, Concepción; Tapia-Benavides, Antonio R.; Falcón-León, Martha; Ariza-Castolo, Armando; Tlahuext, Hugo; Tlahuextl, Margarita

    2015-11-01

    2-{[(Ammoniumacetyl)amino]methyl}-1H-benzimidazol-3-ium dichloride 4, 2-{[(2-ammoniumpropanoyl)amino]methyl}-1H-benzimidazol-3-ium dichloride 5, and 2-{[(2-ammonium-3-phenylpropanoyl)amino]methyl}-1H-benzimidazol-3-ium dichloride 6 amino amides were synthesized via condensation of 2AMBZ dihydrochloride with the corresponding amino acid. Compounds 7-12 were obtained by replacing chloride ions (in salts 4-6) with nitrate or tetrachlorozincate ions. The results of X-ray diffraction crystallographic studies indicated that the geometries, charges and sizes of the anions are essential for the formation of the strong hydrogen bond interactions of compounds 4, 5, 9-12. Moreover, in most cases, the presence of water and solvent molecules stabilizes the supramolecular structures of these compounds. Nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy indicated that the presence of chloride or tetrachlorozincate anions increases the acidity of the benzimidazolic and amide groups more significantly than the presence of nitrate anions. However, Quantum Theory of Atoms in Molecules (QTAIM) computations of the crystal structures demonstrate that amino amides interact more strongly with NO3- than with Cl- and ZnCl42- anions; this difference explains the spectroscopic results.

  1. Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amides

    Angélica Díaz

    2014-04-01

    Full Text Available Poly(alkylene dicarboxylates constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amides derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

  2. Synthesis and evaluation of fatty acid amides on the N-oleoylethanolamide-like activation of peroxisome proliferator activated receptor α.

    Takao, Koichi; Noguchi, Kaori; Hashimoto, Yosuke; Shirahata, Akira; Sugita, Yoshiaki

    2015-01-01

    A series of fatty acid amides were synthesized and their peroxisome proliferator-activated receptor α (PPAR-α) agonistic activities were evaluated in a normal rat liver cell line, clone 9. The mRNAs of the PPAR-α downstream genes, carnitine-palmitoyltransferase-1 and mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase, were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) as PPAR-α agonistic activities. We prepared nine oleic acid amides. Their PPAR-α agonistic activities were, in decreasing order, N-oleoylhistamine (OLHA), N-oleoylglycine, Oleamide, N-oleoyltyramine, N-oleoylsertonin, and Olvanil. The highest activity was found with OLHA. We prepared and evaluated nine N-acylhistamines (N-acyl-HAs). Of these, OLHA, C16:0-HA, and C18:1Δ(9)-trans-HA showed similar activity. Activity due to the different chain length of the saturated fatty acid peaked at C16:0-HA. The PPAR-α antagonist, GW6471, inhibited the induction of the PPAR-α downstream genes by OLHA and N-oleoylethanolamide (OEA). These data suggest that N-acyl-HAs could be considered new PPAR-α agonists. PMID:25832022

  3. Gene evolution of epoxide hydrolases and recommended nomenclature

    Beetham, J K; Grant, D; Arand, M; Garbarino, J; Kiyosue, T; Pinot, F; Oesch, F; Belknap, W R; Shinozaki, K.; Hammock, B. D.

    1995-01-01

    We have analyzed amino acid sequence relationships among soluble and microsomal epoxide hydrolases, haloacid dehalogenases, and a haloalkane dehalogenase. The amino-terminal residues (1-229) of mammalian soluble epoxide hydrolase are homologous to a haloacid dehalogenase. The carboxy-terminal residues (230-554) of mammalian soluble epoxide hydrolase are homologous to haloalkane dehalogenase, to plant soluble epoxide hydrolase, and to microsomal epoxide hydrolase. The shared identity between t...

  4. Influence of physico-chemical parameters of some barbituric acid derivatives on their retention on an amide embedded RP silica column.

    Jakab, Annamaria; Prodan, Miklos; Forgács, Esther

    2002-03-01

    Retention parameters of 45 different barbituric acid derivatives were determined on an amide embedded RP silica column (Discovery RP-AmideC16) using non-buffered water-acetonitrile eluent systems. Linear correlation were calculated between the logarithm of the capacity factor and the acetonitrile concentration in the eluent. To determine the retention behavior of barbituric acid derivatives, stepwise regression analysis (SRA) and principal component analysis (PCA) followed by two-dimensional nonlinear and modified nonlinear mapping was used. It can be concluded, the retention of barbituric acid derivatives are governed mainly by the steric parameters of the substituents. Principal component analysis indicated that the barbituric acid derivatives have mixed retention on this amide embedded RP silica column in water-acetonitrile eluent. PMID:11836055

  5. Synthesis of [14C]-labelled eicosa-5,8,11-triynoic acid and conversion to anti-inflammatory amides

    A four step synthesis of [5,6-14C]-eicosa-5,8,11-triynoic acid from [14C]-labelled acetylene is described. [14C2]-acetylene was converted to 5-chloro-[1,2-14C]-pentyne via reaction of its monolithium salt with 3-bromo-1-chloropropane. The doubly labelled 5-chloropentyne thus obtained was transformed to [5,6-14C]-hex-5-ynoic acid which was then coupled with 1-chloro-tetradeca-2,5-diyne to give the title compound. Using 2-(2-aminoethoxy)ethanol and 1-(2-hydroxyethyl)piperazine, amides which had previously been found to be potent inhibitors of the 5-lipoxygenase enzyme, were prepared from [14C-labelled eicosatriynoic acid by way of acylimidazole chemistry. (author)

  6. IR-spectra of amides of steroidal alkaloids with lactic acid

    Kastelic-Suhadolc, Tatjana

    2015-01-01

    IR spectra of lactamides of 1,4-tomatidien-3-one, 4-solasoden-3-one, dihydrotomatidine and tomatine were taken and the frequency of the ▫$C=0$▫ amide band compared with that of the lactamides of piperidine and its derivatives, and with that of N-acetyltomatidine. It was found that the ▫$C=0$▫ bands of lactamides of steroidal alkaloids show an unusual but characteristic frequency at 1730-1733 cm▫$^{-1}$▫.

  7. Cysteine amide adduct formation from carboxylic acid drugs via UGT-mediated bioactivation in human liver microsomes.

    Harada, H; Toyoda, Y; Endo, T; Kobayashi, M

    2015-10-01

    Although chemical trapping has been widely used to evaluate cytochrome P450-mediated drug bioactivation, thus far, only a few in vitro-trapping studies have been performed on UDP-glucuronosyltransferase (UGT)-mediated drug bioactivation. In this study, we used cysteine (Cys) as trapping agent to gain new insights into the UGT-mediated bioactivation involving acyl glucuronides of carboxylic acid drugs. Diclofenac, ketoprofen and ibuprofen were incubated in human liver microsomes with UDPGA and Cys, followed by analysis using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). The N-acyl-Cys amide adduct of diclofenac was characterized by mass analysis and was detectable even in photodiode array analysis. Our data indicated that the formation of such adducts reflects the reactivity of the corresponding acyl glucuronides. In addition, it was suggested that the adduct formation requires an N-terminal Cys moiety with both a free amine and a free thiol group, from the results using various cysteine derivatives. We propose that the S-acyl-Cys thioester adduct can form via transacylation of an acyl glucuronide and can then form to an N-acyl-Cys amide adduct through intramolecular S- to N-acyl rearrangement. This series of the reactions has important implications as a possible bioactivation mechanism for covalent binding of carboxylic acid drugs to macromolecules. PMID:26601426

  8. Amides as phase modifiers for N,N'-tetraalkylmalonamide extraction of actinides and lanthanides from nitric acid solutions

    The N,N'-tetraalkylmalonamides are a class of compounds under development for transuranic (TRU) separations under high nitric acid conditions. There are several issues that challenge the further development of these ligands. One is the development of improved synthetic procedures that lend themselves to commercial scale-up. Another major issue is the third-phase formation that occurs when the N,N'-tetraalkylmalonamides are contacted with medium-to-high nitric acid concentrations in hydrocarbon solvents. To address the synthesis issue, the authors have developed a new synthetic approach for preparing these materials. Third-phase formation can be eliminated by addition of diluent modifiers such as tributylphosphate (TBP). TBP is inappropriate if a nonphosphate-containing process stream is required. Amides have been proposed as alternatives for TBP in a variety of applications because of their ease of synthesis and the variety of substituents that can be generated. The authors have been able to develop an amide phase-modified system that extends the working process range of alkylinalonamides (0.5 M) in dodecane: from 3.5 M to 7.5 M nitric acid and in Isopar H (branched hydrocarbon) from 4.0 M to 10.0 M nitric acid using 1.0 M di-2-ethylhexylacetamide/0.5 M alkylmalonamide. The Kd values were comparable to extraction with alkylinalonamide in Isopar H or hydrogenated tetrapropylene (TPH) solvents. The overall extraction system was more robust than the phase-uninodified system allowing for greater temperature and acid concentration fluctuations without third-phase formation

  9. Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

    Rajendra Surasani

    2012-11-01

    Full Text Available Simple and efficient procedures for palladium-catalyzed cross-coupling reactions of N-substituted 4-bromo-7-azaindole (1H-pyrrole[2,3-b]pyridine, with amides, amines, amino acid esters and phenols through C–N and C–O bond formation have been developed. The C–N cross-coupling reaction of amides, amines and amino acid esters takes place rapidly by using the combination of Xantphos, Cs2CO3, dioxane and palladium catalyst precursors Pd(OAc2/Pd2(dba3. The combination of Pd(OAc2, Xantphos, K2CO3 and dioxane was found to be crucial for the C–O cross-coupling reaction. This is the first report on coupling of amides, amino acid esters and phenols with N-protected 4-bromo-7-azaindole derivatives.

  10. Epoxy fatty acids and inhibition of the soluble epoxide hydrolase selectively modulate GABA mediated neurotransmission to delay onset of seizures.

    Bora Inceoglu

    Full Text Available In the brain, seizures lead to release of large amounts of polyunsaturated fatty acids including arachidonic acid (ARA. ARA is a substrate for three major enzymatic routes of metabolism by cyclooxygenase, lipoxygenase and cytochrome P450 enzymes. These enzymes convert ARA to potent lipid mediators including prostanoids, leukotrienes and epoxyeicosatrienoic acids (EETs. The prostanoids and leukotrienes are largely pro-inflammatory molecules that sensitize neurons whereas EETs are anti-inflammatory and reduce the excitability of neurons. Recent evidence suggests a GABA-related mode of action potentially mediated by neurosteroids. Here we tested this hypothesis using models of chemically induced seizures. The level of EETs in the brain was modulated by inhibiting the soluble epoxide hydrolase (sEH, the major enzyme that metabolizes EETs to inactive molecules, by genetic deletion of sEH and by direct administration of EETs into the brain. All three approaches delayed onset of seizures instigated by GABA antagonists but not seizures through other mechanisms. Inhibition of neurosteroid synthesis by finasteride partially blocked the anticonvulsant effects of sEH inhibitors while the efficacy of an inactive dose of neurosteroid allopregnanolone was enhanced by sEH inhibition. Consistent with earlier findings, levels of prostanoids in the brain were elevated. In contrast, levels of bioactive EpFAs were decreased following seizures. Overall these results demonstrate that EETs are natural molecules which suppress the tonic component of seizure related excitability through modulating the GABA activity and that exploration of the EET mediated signaling in the brain could yield alternative approaches to treat convulsive disorders.

  11. Preparation and surface active properties of oxypropylated diol monoesters of fatty acids with an amide oxime terminal group

    Eissa, A. M.F.

    1994-10-01

    Full Text Available Locally produced non-edible oil, namely, rice bran oil (R.B.O. was utilized as starting materials for preparing new nonionic surfactant. Oxypropylated diol monoesters of linoleic and rice bran oil fatty acids were prepared. Also amide oxime derivatives were obtained. Surface active properties of these compounds were measured. Under neutral condition amide eximes served as nonionic surfactants and their properties were similar to other oxypropylated monoesters.

    Se ha utilizado un aceite no comestible de producción local, denominado, aceite de salvado de arroz (R.B.O. como materia prima para la preparación de nuevos tensioactivos no iónicos. Se prepararon diol monoésteres oxipropilados de ácido linoleico y ácidos grasos de aceite de salvado de arroz. También se obtuvieron los derivados de amido oxima. Se midieron las propiedades de tensión superficial de estos compuestos. Bajo condiciones neutras las amido eximas sirvieron como tensioactivos no iónicos y sus propiedades fueron similares a los de otros monoésteres oxipropilados.

  12. In vitro activity of pipecolic acid amide of clindamycin (U-57930E) on anaerobic bacteria compared with those of clindamycin, cefoxitin, and chloramphenicol.

    Dhawan, V K; Bansal, M B; Thadepalli, H

    1982-01-01

    In vitro activity of pipecolic acid amide of clindamycin (U-57930E) against 265 isolates of anaerobic bacteria, including 66 strains of Bacteroides fragilis, was compared with those of clindamycin, chloramphenicol, and cefoxitin. At therapeutically achievable concentrations, the activities of all four antibiotics against anaerobic bacteria were similar.

  13. Detection and qualitative analysis of fatty acid amides in the urine of alcoholics using HPLC-QTOF-MS.

    Dabur, Rajesh; Mittal, Ashwani

    2016-05-01

    Fatty acid amides (FAAs) in alcoholism lead to liver diseases. These amides have been reported in plasma and in other organs of the body, while their detection or presence in the urine is still unknown. Therefore, the focus of the current study was to detect and analyze FAAs qualitatively in urine samples of alcoholics. Furthermore, the effects of Tinospora cordifolia (hepatoprotective medicinal plant) intervention on FAA levels in moderate alcoholics were also analyzed. In the study, asymptomatic chronic alcoholics (n = 22) without chronic liver disease and nonalcoholic healthy volunteers (n = 24) with a mean age of 39 ± 2.0 years were selected. The first-pass urine and fasting blood samples were collected in the morning on day 0 and day 14 after T. cordifolia water extract (TCE) treatment and analyzed using automated biochemistry analyzer and HPLC-QTOF-MS. Results indicated the increased levels of serum triglycerides, cholesterol, and liver function enzymes in alcoholic subjects, which were significantly down-regulated by TCE intervention. Multivariate discrimination analysis of QTOF-MS data showed increased urinary levels of oleoamide (2.55-fold), palmitamide (5.6-fold), and erucamide (1.6-fold) in alcoholics as compared to control subjects. Levels of oleamide (1.8-fold), palmitamide (1.7-fold), and linoleamide (1.5-fold) were found to be increased in plasma. Treatment with TCE in alcoholics (3.0 g lyophilized water extract/day) significantly decreased the plasma and urinary levels of all FAAs except linoleamide. The HPLC-QTOF-MS approach for FAAs analysis in both urinary and plasma samples of alcoholics worked very well. Moreover, findings (i.e., increased levels of FAAs in urine and in plasma) further support other findings that these amides play a very important role in alcoholism. Further, like our previous findings, TCE proved its hepatoprotective effect against alcoholism not only by lowering the levels of these detected FAAs, but also by decreasing the

  14. Synthesis of the Amide Derivatives of 3-[1-(3-Pyridazinyl)-5-phenyl-1H-pyrazole-3-yl]propanoic Acids as Potential Analgesic Compounds

    BANOĞLU, Erden; Şüküroğlu, Murat; ERGÜN, Burcu ÇALIŞKAN

    2007-01-01

    A series of structurally diverse amide derivatives of 3-[1-(3-pyridazinyl)-5-phenyl-1H-pyrazole-3-yl]propanoic acids were prepared and tested for their in vivo analgesic activity using an acetic acid induced writhing test. All the test compounds displayed approximately equipotent analgesic activity to aspirin. The results showed that the analgesic activity of 5a, 5f, 5n, and 5o is significantly higher than that of 5d.

  15. New optically active poly(amide-imide)s based on N,N '-(pyromellitoyl)-bis-L-amino acid and methylene diphenyl-4,4 '-diisocyanate

    Tian, Xiaoyu; Yao, Jinshui; Zhang, Xian;

    2014-01-01

    Five new optically active poly(amide-imide)s were synthesized through the direct polycondensation reaction between chiral N,N-(pyromellitoyl)-bis-L-amino acids and methylene diphenyl-4,4-diisocyanate in a medium consisting of N-methyl-2-pyrrolidone (NMP) and xylene. The resulted polymers were ful......,N-dimethyl formamide, dimethyl sulfoxide (DMSO), NMP, sulfuric acid, and para-methyl phenol. Same specific rotations of these polymers in these different solvents were obtained....

  16. Relationship between chromatographic resolution and amide structure of chiral 2-hydroxy acids as O-(-)-menthoxycarbonylated diastereomeric derivatives for enantiomeric separation on achiral gas chromatography.

    Cha, Eunju; Kim, Sohee; Lee, Kang Mi; Kim, Ho Jun; Kim, Ki Hun; Kwon, Oh-Seung; Park, Ki Duk; Lee, Jaeick

    2016-02-15

    The relationship between chromatographic resolution and amide structure of chiral 2-hydroxy acids as O-(-)-menthoxycarbonylated diastereomeric derivatives on achiral gas chromatography was investigated to elucidate the best diastereomeric conformation for enantiomeric separation of chiral 2-hydroxy acids. Thirteen chiral 2-hydroxy acids were converted into nine different diastereomeric O-(-)-menthoxycarbonylated amide derivatives using the primary, secondary and cyclic amines to achieve complete enantiomeric separation through an achiral column. Each enantiomeric pair of 2-hydroxy acids as O-(-)-menthoxycarbonylated tert-butylamide derivatives was resolved on both the DB-5 and DB-17 columns with resolution factors ranging from 1.7 to 4.8 and 1.7 to 3.4, respectively. The results revealed that the structure of the amide moiety is shown to significantly affect chromatographic resolution. In addition, O-(-)-menthoxycarbonylated tert-butylamide derivatives were shown to be the best diastereomeric conformations for enantiomeric separation of 2-hydroxy acids. When comparing with our previous O-trifluoroacetylated(-)-menthyl ester derivatization method, the present results suggested that size differences between groups attached to the chiral center and conformational rigidity can have stronger effects on resolution than the distance between chiral centers. The elution of R- and S-stereoisomers was affected by the class of amine; i.e., primary, secondary, or cyclic, regardless of the substituents on the amine group, the structure of the 2-hydroxy acid, and the polarity of the column. PMID:26800225

  17. Efficacy of boswellic acid on lysosomal acid hydrolases, lipid peroxidation and anti-oxidant status in gouty arthritic mice

    Evan Prince Sabina; Haridas Indu; Mahaboobkhan Rasool

    2012-01-01

    Objective:To evaluate the efficacy of boswellic acid against monosodium urate crystal-induced inflammation in mice. Methods:The mice were divided into four experimental groups. Group I served as control;mice in group II were injected with monosodium urate crystal;group III consisted of monosodium urate crystal-induced mice who were treated with boswellic acid (30 mg/kg/b.w.);group IV comprised monosodium urate crystal-induced mice who were treated with indomethacin (3 mg/kg/b.w.). Paw volume and levels/activities of lysosomal enzymes, lipid peroxidation, anti-oxidant status and inflammatory mediator TNF-αwere determined in control and monosodium urate crystal-induced mice. In addition, the levels of β-glucuronidase and lactate dehydrogenase were also measured in monosodium urate crystal-incubated polymorphonuclear leucocytes (PMNL) in vitro. Results:The activities of lysosomal enzymes, lipid peroxidation, and tumour necrosis factor-αlevels and paw volume were increased significantly in monosodium urate crystal-induced mice, whereas the activities of antioxidant status were in turn decreased. However, these changes were modulated to near normal levels upon boswellic acid administration. In vitro, boswellic acid reduced the level of β-glucuronidase and lactate dehydrogenase in monosodium urate crystal-incubated PMNL in concentration dependent manner when compared with control cells. Conclusions: The results obtained in this study further strengthen the anti-inflammatory/antiarthritic effect of boswellic acid, which was already well established by several investigators.

  18. Synthesis and characterization of new optically active copoly(amid-imide)s based on N-phthalimido-L-aspartic acid and aromatic diamines

    Khalil; Faghihi; Hamidreza; Alimohammadi

    2010-01-01

    In this article,six new optically active copoly(amide-imide)s(10a-f) were synthesized through the direct polycondensation reaction of N-phthalimido-L-aspartic acid(4) with 1,5-diamino naphthalene(8),3,4-diamino benzophenone(9) in the presence of therphthahc acid(7),fumaric acid(6) and adipic acid(5) as a second diacid in a medium consisting of N-methyl-2-pyrrolidone,triphenyl phosphite, calcium chloride and pyridine.The resulting copolymers were fully characterized by means of FT-IR spectroscopy,elementa...

  19. Role of amidation in bile acid effect on DNA synthesis by regenerating mouse liver.

    Barbero, E R; Herrera, M C; Monte, M J; Serrano, M A; Marin, J J

    1995-06-01

    Effect of bile acids on DNA synthesis by the regenerating liver was investigated in mice in vivo after partial hepatectomy (PH). Radioactivity incorporation into DNA after [14C]thymidine intraperitoneal administration peaked at 48 h after PH. At this time a significant taurocholate-induced dose-dependent reduction in DNA synthesis without changes in total liver radioactivity content was found (half-maximal effect at approximately 0.1 mumol/g body wt). Effect of taurocholate (0.5 mumol/g body wt) was mimicked by chocolate, ursodeoxycholate, deoxycholate, dehydrocholate, tauroursodeoxycholate, taurochenodeoxycholate, and taurodeoxycholate. In contrast, chenodeoxycholate, glycocholate, glycochenodeoxycholate, glycoursodeoxycholate, glycodeoxycholate, 5 beta-cholestane, bromosulfophthalein, and free taurine lacked this effect. No relationship between hydrophobic-hydrophilic balance and inhibitory effect was observed. Analysis by high-performance liquid chromatography indicated that inhibition of thymidine incorporation into DNA was not accompanied by an accumulation of phosphorylated DNA precursors in the liver but rather by a parallel increase in nucleotide catabolism. Bile acid-induced modifications in DNA synthesis were observed in vivo even in the absence of changes in toxicity tests, which suggests that the inhibitory effect shared by most unconjugated and tauroconjugated bile acids but not by glycoconjugated bile acids should be accounted for by mechanisms other than nonselective liver cell injury. PMID:7611405

  20. New co-crystal and salt form of sulfathiazole with carboxylic acid and amide

    Ranita Samanta; Shipra Kanaujia; C Malla Reddy

    2014-09-01

    One co-crystal and one salt of an antibacterial drug sulfathiazole with 4-aminobenzamide and 2,4-dinitrobenzoic acid have been synthesized. These new forms are characterized by single crystal X-ray diffraction, infrared spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In solid state, sulfathiazole preferentially adopts the imidine tautomeric form.

  1. Selective separation of uranium(VI) on a chelating styrene-DVB based resin containing quinaldinic acid amide group

    A new chelating styrene-DVB based resin containing quinaldinic acid amide functional group, has been synthesised and characterised. The sorption patterns of Na(I), K(I), Be(II), Ca(II), Mg(II), Zn(II), Cd(II), Cu(II), Pb(II), Ni(II), Bi(III), Fe(III), Ti(IV) and U(VI) have been studied as a function of pH. The resin sorbs U(VI) over a wide range of pH (1.0 to 4.0) with a maximum sorption of 0.32 mmol/g at pH 3.5 to 4.0. Zn(II), Cd(II), Cu(II), Na(II), Pb(II), Fe(III) and Ti(IV) are also sorbed to different extents by the resin while Na(I), K(I), Be(II), Ca(II), Mg(II) and Bi(III) are not sorbed. Conditions for separation of U(VI) from these metal ions have been identified. The eluting agent used for U(VI) is 3 N HNO3 and the recovery recorded is about 99.9 per cent (author). 12 refs., 3 tabs

  2. Calix[6]arene bearing carboxylic acid and amide groups in polymeric CTA membrane

    Calix[6]arene having both carboxylic acid (1,3,5-) and carboxamide (2,4,6-) in an alternative way was synthesized. Transport rates of alkali and alkaline-earth metal ions were tested in bulk liquid membrane and polymer inclusion membrane. Ba2+ ion was found to give the highest transport rate among tested metal ions in both BLM and PIM system. In PIM system, high durability (longer than 30 days) of the membrane was observed

  3. Brucella abortus choloylglycine hydrolase affects cell envelope composition and host cell internalization.

    María Inés Marchesini

    Full Text Available Choloylglycine hydrolase (CGH, E.C. 3.5.1.24 is a conjugated bile salt hydrolase that catalyses the hydrolysis of the amide bond in conjugated bile acids. Bile salt hydrolases are expressed by gastrointestinal bacteria, and they presumably decrease the toxicity of host's conjugated bile salts. Brucella species are the causative agents of brucellosis, a disease affecting livestock and humans. CGH confers Brucella the ability to deconjugate and resist the antimicrobial action of bile salts, contributing to the establishment of a successful infection through the oral route in mice. Additionally, cgh-deletion mutant was also attenuated in intraperitoneally inoculated mice, which suggests that CGH may play a role during systemic infection other than hydrolyzing conjugated bile acids. To understand the role CGH plays in B. abortus virulence, we infected phagocytic and epithelial cells with a cgh-deletion mutant (Δcgh and found that it is defective in the internalization process. This defect along with the increased resistance of Δcgh to the antimicrobial action of polymyxin B, prompted an analysis of the cell envelope of this mutant. Two-dimensional electrophoretic profiles of Δcgh cell envelope-associated proteins showed an altered expression of Omp2b and different members of the Omp25/31 family. These results were confirmed by Western blot analysis with monoclonal antibodies. Altogether, the results indicate that Brucella CGH not only participates in deconjugation of bile salts but also affects overall membrane composition and host cell internalization.

  4. Separation and recovery of palladium from acidic waste using dithiodiglycol-amide encapsulated polymeric beads

    Palladium selective ligand, N,N,N',N'-tetra-(2-ethylhexyl)-dithiodiglycolamide (DTDGA), was encapsulated in polymeric composite beads under simple laboratory conditions. The composite beads were evaluated for separation and recovery of palladium from acidic aqueous waste. The beads showed maximum uptake of Pd at 3.0 M HCl. Pd sorption kinetics was found to be fast and, the kinetics data fits well in to the pseudo second-order equation model for the sorption of palladium ions onto the composite beads. Different sorption isotherm models were applied to the experimental data. Equilibrium data are represented well by the Langmuir isotherm equation, with a monolayer sorption capacity of 1.56 mg/g for the swollen beads. Batch extraction studies showed negligible uptake of Fe, Cr, Ni, and Pt, thus showing very high selectivity and extractability of the composite beads for palladium. (author)

  5. A study of fragmentation of protonated amides of some acylated amino acids by tandem mass spectrometry: observation of an unusual nitrilium ion.

    Talaty, Erach R; Young, Sarah M; Dain, Ryan P; Van Stipdonk, Michael J

    2011-05-15

    A tandem mass spectrometric study of a series of secondary amides of acetylglycine and hippuric acid utilizing electrospray ionization (ESI) was conducted. Among the fragment ions observed was an unusual one, which we have determined to be a nitrilium ion having the structure CH3-C≡N⊕-Ph or Ph-C≡N⊕-Ph by loss of the full mass of glycine as a neutral fragment. A mechanism that we propose involves an initial protonation of the oxygen atom at the N-terminus, followed by cyclization to a five-membered imidazolium ring, and its subsequent collapse to the nitrilium ion. This mechanism is supported by extensive isotopic labels and considerable variation of substituents. A similar study of the amides of acyl β-alanine and acyl γ-aminobutyric acid revealed that the former furnishes the same nitrilium ion, but not the latter. Thus, a six-membered intermediate is also possible and capable of losing the full mass of β-alanine as a neutral fragment. When the size of the ring is forced to be seven-membered, this pathway is blocked. When this study was expanded to include a variety of N-acylproline amides, the nitrilium ion was observed in 100% abundance only when the acyl group was acetyl. Thus a proline effect (involvement of a strained bicyclic [3.3.0] structure) is being observed. PMID:21488111

  6. Preparation of different amides via Ritter reaction from alcohols and nitriles in the presence of silica-bonded N- propyl sulphamic acid (SBNPSA) under solvent-free conditions

    Maryam-Sadat Shakeri; Hassan Tajik; Khodabakhsh Niknam

    2012-09-01

    A number of methods have been proposed for the modification of the Ritter reaction. However, many of these methods involve the use of strongly acidic conditions, stoichiometric amounts of reagents, harsh reaction conditions and extended reaction times. Therefore, the development of mild, efficient, convenient and benign reagents for the Ritter reaction is desirable. In this research, we have developed a clean and environmentally friendly protocol for the synthesis of amides by using different benzylic or tertiary alcohols and different nitriles in the presence of silica-bonded N- propyl sulphamic acid (SBNPSA) as catalyst under solvent-free conditions in high yields.

  7. Electrospun Scaffolds from Low Molecular Weight Poly(ester amides Based on Glycolic Acid, Adipic Acid and Odd or Even Diamines

    Sara Keiko Murase

    2015-05-01

    Full Text Available Electrospinning of regular poly(ester amides (PEAs constituted by glycolic acid, adipic acid and diamines with five and six carbon atoms has been carried out. Selected PEAs were constituted by natural origin products and could be easily prepared by a polycondensation method that avoids tedious protection and deprotection steps usually required for obtaining polymers with a regular sequence. Nevertheless, the synthesis had some limitations that mainly concerned the final low/moderate molecular weight that could be attained. Therefore, it was considered interesting to evaluate if electrospun scaffolds could still be prepared taking also advantage of the capability of PEAs to establish intermolecular hydrogen bonds. Results indicated that the crucial factor was the control of polymer concentration in the electrospun solution, being necessary that this concentration was higher than 40% (w/v. The PEA with the lowest molecular weight (Mw close to 8000 g/mol was the most appropriate to obtain electrospun samples with a circular cross-section since higher molecular sized polymers show solvent retention problems derived from the high viscosity of the electrospun solution that rendered ribbon-like morphologies after the impact of fibers into the collector. The studied PEAs were semicrystalline and biodegradable, as demonstrated by calorimetric and degradation studies. Furthermore, the new scaffolds were able to encapsulate drugs with anti-inflammatory and bacteriostatic activities like ketoprofen. The corresponding release and bactericide activity was evaluated in different media and against different bacteria. Finally, biocompatibility was demonstrated using both fibroblast and epithelial cell lines.

  8. Zinc(II) complexes with heterocyclic ether, acid and amide. Crystal structure, spectral, thermal and antibacterial activity studies

    Jabłońska-Wawrzycka, Agnieszka; Rogala, Patrycja; Czerwonka, Grzegorz; Hodorowicz, Maciej; Stadnicka, Katarzyna

    2016-02-01

    The reaction of zinc salts with heterocyclic ether (1-ethoxymethyl-2-methylimidazole (1-ExMe-2-MeIm)), acid (pyridine-2,3-dicarboxylic acid (2,3-pydcH2)) and amide (3,5-dimethylpyrazole-1-carboxamide (3,5-DMePzCONH2)) yielded three new zinc complexes formulated as [Zn(1-ExMe-2-MeIm)2Cl2] 1, fac-[Zn(H2O)6][Zn(2,3-pydcH)3]22 and [Zn(3,5-DMePz)2(NCO)2] 3. Complexes of 1 and 3 are four-coordinated with a tetrahedron as coordination polyhedron. However, compound 2 forms an octahedral cation-anion complex. The complex 3 was prepared by eliminating of the carboxamide group from the ligand and then the 3,5-dimethylpyrazole (3,5-DMePz) and isocyanates formed were employed as new ligands. The IR and X-ray studies have confirmed a bidentate fashion of coordination of the 2,3-pydcH and monodentate fashion of coordination of the 1-ExMe-2-MeIm and 3,5-DMePz to the Zn(II) ions. The crystal packing of Zn(II) complexes are stabilized by intermolecular classical hydrogen bonds of O-H⋯O and N-H⋯O types. The most interesting feature of the supramolecular architecture of complexes is the existence of C-H⋯O, C-H⋯Cl and C-H⋯π interactions and π⋯π stacking, which also contributes to structural stabilisation. The correlation between crystal structure and thermal stability of zinc complexes is observed. In all compounds the fragments of ligands donor-atom containing go in the last steps. Additionally, antimicrobial activities of compounds were carried out against certain Gram-positive and Gram-negative bacteria and counts of CFU (colony forming units) were also determined. The achieved results confirmed a significant antibacterial activity of some tested zinc complexes. On the basis of the Δ log CFU values the antibacterial activity of zinc complexes follows the order: 3 > 2 > 1. Influence a number of N-donor atoms in zinc environment on antibacterial activity is also observed.

  9. Cholesterol-Lowering Potentials of Lactic Acid Bacteria Based on Bile-Salt Hydrolase Activity and Effect of Potent Strains on Cholesterol Metabolism In Vitro and In Vivo

    Cheng-Chih Tsai

    2014-01-01

    Full Text Available This study collected different probiotic isolates from animal and plant sources to evaluate the bile-salt hydrolase activity of probiotics in vitro. The deconjugation potential of bile acid was determined using high-performance liquid chromatography. HepG2 cells were cultured with probiotic strains with high BSH activity. The triglyceride (TG and apolipoprotein B (apo B secretion by HepG2 cells were evaluated. Our results show that the BSH activity and bile-acid deconjugation abilities of Pediococcus acidilactici NBHK002, Bifidobacterium adolescentis NBHK006, Lactobacillus rhamnosus NBHK007, and Lactobacillus acidophilus NBHK008 were higher than those of the other probiotic strains. The cholesterol concentration in cholesterol micelles was reduced within 24 h. NBHK007 reduced the TG secretion by 100% after 48 h of incubation. NBHK002, NBHK006, and NBHK007 could reduce apo B secretion by 33%, 38%, and 39%, respectively, after 24 h of incubation. The product PROBIO S-23 produced a greater decrease in the total concentration of cholesterol, low-density lipoprotein, TG, and thiobarbituric acid reactive substance in the serum or livers of hamsters with hypercholesterolemia compared with that of hamsters fed with a high-fat and high-cholesterol diet. These results show that the three probiotic strains of lactic acid bacteria are better candidates for reducing the risk of cardiovascular disease.

  10. Molecular cloning and sequence analysis of complementary DNA encoding rat mammary gland medium-chain S-acyl fatty acid synthetase thio ester hydrolase

    Poly(A) + RNA from pregnant rat mammary glands was size-fractionated by sucrose gradient centrifugation, and fractions enriched in medium-chain S-acyl fatty acid synthetase thio ester hydrolase (MCH) were identified by in vitro translation and immunoprecipitation. A cDNA library was constructed, in pBR322, from enriched poly(A) + RNA and screened with two oligonucleotide probes deduced from rat MCH amino acid sequence data. Cross-hybridizing clones were isolated and found to contain cDNA inserts ranging from ∼ 1100 to 1550 base pairs (bp). A 1550-bp cDNA insert, from clone 43H09, was confirmed to encode MCH by hybrid-select translation/immunoprecipitation studies and by comparison of the amino acid sequence deduced from the DNA sequence of the clone to the amino acid sequence of the MCH peptides. Northern blot analysis revealed the size of the MCH mRNA to be 1500 nucleotides, and it is therefore concluded that the 1550-bp insert (including G x C tails) of clone 43H09 represents a full- or near-full-length copy of the MCH gene. The rat MCH sequence is the first reported sequence of a thioesterase from a mammalian source, but comparison of the deduced amino acid sequences of MCH and the recently published mallard duck medium-chain S-acyl fatty acid synthetase thioesterase reveals significant homology. In particular, a seven amino acid sequence containing the proposed active serine of the duck thioesterase is found to be perfectly conserved in rat MCH

  11. Aminocarbonylation of 4-iodo-1H-imidazoles with an amino acid amide nucleophile: synthesis of constrained H-Phe-Phe-NH2 analogues.

    Skogh, Anna; Fransson, Rebecca; Sköld, Christian; Larhed, Mats; Sandström, Anja

    2013-12-01

    A simple and an expedient process to prepare 5-aryl-1-benzyl-1H-imidazole-4-carboxamides by the aminocarbonylation of 5-aryl-4-iodo-1H-imidazoles using ex situ generation of CO from Mo(CO)6 with an amino acid amide nucleophile is reported. Furthermore, a microwave-assisted protocol for the direct C-5 arylation of 1-benzyl-1H-imidazole and a regioselective C-4 iodination method to acquire starting material for our aminocarbonylation are presented. The method can be used to prepare imidazole based peptidomimetics, herein exemplified by the synthesis of constrained H-Phe-Phe-NH2 analogues. PMID:24171628

  12. Extraction of Np(IV), Np(VI), Pu(IV) and U(VI) with amides, BEHSO and CMPO from nitric acid medium

    The extraction of Np(IV), Np(VI), Pu(IV) and U(VI) from a nitric acid medium has been carried out with dibutyldecanamide (DBDA), dihexyldecanamide (DHDA), bis-2-ethylhexylsulphoxide (BEHSO) and octyl(phenyl)-N-N-diisobutyl-carbamolymethylphosphine oxide (CMPO) using n-dodecane as the diluent. The order of extraction for the metal ions is CMPO>BEHSO>DHDA>DBDA. The species extracted into the organic phase was found to be the disolvate with all the extractants while using hexavalent metal ions Np(VI) and U(VI) and also with tetravalent ions Np(IV) and Pu(IV) in the case of BEHSO and CMPO. However, in the case of DBDA and DHDA, Np(IV) and Pu(IV) were extracted as the trisolvate species. The equilibrium constant (K) for the formation of the above species has been evaluated after applying the possible correction factors. In general, logK increases with increasing basicity of the extractants. In the case of amides, the plot of logK verses kH (acid uptake equilibrium constant) gave straight lines which could be represented by the empirical equation: logKU(VI)=5.17 kH+0.18 and logKPu(IV)=3.11 kH+1.81 for the respective metal ions. With the help of these empirical equations it is possible to predict the equilibrium constant values of amide complexes of U(VI) or Pu(IV) if the kH values of amides are known. The solid complexes of U(VI) with DHDA and CMPO were synthesized and characterized by elemental analysis and IR spectra. Two molecules of DHDA and only one molecule of CMPO are bound with U(VI). The bidentate nature of CMPO in its solid species has been confirmed. (orig.)

  13. Cyanuric acid hydrolase from Azorhizobium caulinodans ORS 571: crystal structure and insights into a new class of Ser-Lys dyad proteins.

    Seunghee Cho

    Full Text Available Cyanuric acid hydrolase (CAH catalyzes the hydrolytic ring-opening of cyanuric acid (2,4,6-trihydroxy-1,3,5-triazine, an intermediate in s-triazine bacterial degradation and a by-product from disinfection with trichloroisocyanuric acid. In the present study, an X-ray crystal structure of the CAH-barbituric acid inhibitor complex from Azorhizobium caulinodans ORS 571 has been determined at 2.7 Å resolution. The CAH protein fold consists of three structurally homologous domains forming a β-barrel-like structure with external α-helices that result in a three-fold symmetry, a dominant feature of the structure and active site that mirrors the three-fold symmetrical shape of the substrate cyanuric acid. The active site structure of CAH is similar to that of the recently determined AtzD with three pairs of active site Ser-Lys dyads. In order to determine the role of each Ser-Lys dyad in catalysis, a mutational study using a highly sensitive, enzyme-coupled assay was conducted. The 10⁹-fold loss of activity by the S226A mutant was at least ten times lower than that of the S79A and S333A mutants. In addition, bioinformatics analysis revealed the Ser226/Lys156 dyad as the only absolutely conserved dyad in the CAH/barbiturase family. These data suggest that Lys156 activates the Ser226 nucleophile which can then attack the substrate carbonyl. Our combination of structural, mutational, and bioinformatics analyses differentiates this study and provides experimental data for mechanistic insights into this unique protein family.

  14. Synthesis and characterization of heat-resistant and soluble poly(amide-imide)s from unsymmetrical dicarboxylic acid containing 2-(triphenyl phosphoranylidene) moiety and various aromatic diamines

    Seema Agrawal; Anudeep Kumar Narula

    2015-04-01

    An unsymmetrical and non-coplaner heterocyclic phosphorus containing dicarboxylic acid monomer, (DCA-3) is successfully synthesized with high purity. A series of novel aromatic poly(amide-imide)s having ether or/sulphur or/fluorine or/phosphorus containing phenyl moieties in their backbone are then prepared via a direct phosphorylation polycondensation of synthesized dicarboxylic acid with various aromatic diamines. Chemical structures of DCA-3 as well as resulting polymers are confirmed by FT-IR, NMR spectroscopic techniques and elemental analysis. These polymers are readily soluble in a variety of aprotic polar solvents such as NMP, DMSO, DMAc and DMF, etc. UV spectra showed that all poy(amide-imide)s films exhibit high optical transparency. In addition, the glass transition temperatures (Tg) of these polymers were determined by differential scanning calorimetry and found in the range 271–346°C. Furthermore, thermogravimetric analysis of these polymers showed good thermal stability, 10% weight loss at temperature in excess of 538°C and char yield at 700°C in nitrogen ranging from 68 to 79%. From wide-angle X-ray diffraction experiments, all polymers showed amorphous behaviour.

  15. Effects of soluble epoxide hydrolase inhibitor on the expression of fatty acid synthase in peripheral blood mononuclear cell in patients with acute coronary syndrome

    Zhao Xuan

    2013-01-01

    Full Text Available Abstract Background Researches have shown that soluble epoxide hydrolase inhibitors (sEHi can protect against the development of atherosclerosis. Simultaneously, emerging evidences have implicated the association between fatty acid synthase (FAS and acute coronary syndrome (ACS. We tested the hypothesis that sEHi could reduce the occurrence of ACS by regulating FAS. Methods Hospitalized ACS patients were selected as the ACS group (n = 65 while healthy normal subjects as the control group (n = 65. The blood levels of lipoproteins, fasting glucose, myocardial enzyme and high-sensitivity C-reactive protein (hs-CRP were measured within 24 hours after admission. The peripheral blood mononuclear cells (PBMCs were isolated and cultured. Trans-4-[4-(3-Adamantan-1-ylureidocyclohexyloxy] benzoic acid (t-AUCB, a kind of sEHi, was then added to cells in various concentrations (0, 10, 50, 100 μmol/L. The expression of FAS, interleukin-6 (IL-6 mRNA and protein was detected by real-time PCR or Western blot, respectively. Results (1 Compared with the control group, the serum concentration of hs-CRP in the ACS group was increased (PPPPP Conclusions sEH inhibition regulated FAS and inhibited inflammation in cultured PBMCs from ACS patients, a mechanism that might prevent rupture of atherosclerotic lesions and protect against development of ACS.

  16. Inhibition of soluble epoxide hydrolase by cis-4-[4-(3-adamantan-1-ylureido)cyclohexyl-oxy]benzoic acid exhibits antihypertensive and cardioprotective actions in transgenic rats with angiotensin II-dependent hypertension

    Neckář, Jan; Kopkan, L.; Husková, Z.; Kolář, František; Papoušek, František; Kramer, H. J.; Hwang, S.H.; Hammock, B.D.; Imig, J. D.; Malý, J.; Netuka, I.; Ošťádal, Bohuslav; Červenka, L.

    2012-01-01

    Roč. 122, č. 11 (2012), s. 513-525. ISSN 0143-5221 R&D Projects: GA AV ČR(CZ) IAAX01110901; GA AV ČR(CZ) KAN200520703; GA MŠk(CZ) 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : hypertension * angiotensin II * kidney * epoxyeicosatrienoic acids * soluble epoxide hydrolase inhibitor * myocardial ischemia/reperfusion injury Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.859, year: 2012

  17. Protective effect of squalene on certain lysosomal hydrolases and free amino acids in isoprenaline-induced myocardial infarction in rats

    Farvin, Sabeena; Surendraraj, A.; Anandan, R.

    2010-01-01

    This study was aimed to evaluate the preventive role of squalene on free amino acids and lysosomal alterations in experimentally induced myocardial infarction in rats. The levels of lysosomal enzymes (beta-glucuronidase, beta-galactosidase, beta-glucosidase, acid phosphatase and cathepsin D) in...... plasma and lysosomal fractions, hydroxyproline content and free amino acids in heart tissue were determined. Isoprenaline administration to rats resulted in decreased stability of the membranes which was reflected by significantly (p...

  18. Hierarchical classification of glycoside hydrolases.

    Naumoff, D G

    2011-06-01

    This review deals with structural and functional features of glycoside hydrolases, a widespread group of enzymes present in almost all living organisms. Their catalytic domains are grouped into 120 amino acid sequence-based families in the international classification of the carbohydrate-active enzymes (CAZy database). At a higher hierarchical level some of these families are combined in 14 clans. Enzymes of the same clan have common evolutionary origin of their genes and share the most important functional characteristics such as composition of the active center, anomeric configuration of cleaved glycosidic bonds, and molecular mechanism of the catalyzed reaction (either inverting, or retaining). There are now extensive data in the literature concerning the relationship between glycoside hydrolase families belonging to different clans and/or included in none of them, as well as information on phylogenetic protein relationship within particular families. Summarizing these data allows us to propose a multilevel hierarchical classification of glycoside hydrolases and their homologs. It is shown that almost the whole variety of the enzyme catalytic domains can be brought into six main folds, large groups of proteins having the same three-dimensional structure and the supposed common evolutionary origin. PMID:21639842

  19. Increased leukotriene B(4) production, complement C3 conversion and acid hydrolase enzyme concentrations in different leucocyte sub-populations of dogs with atopic dermatitis.

    Breathnach, R; Donahy, C; Jones, B R; Bloomfield, F J

    2006-01-01

    Various markers of the inflammatory response were measured in peripheral blood mononuclear cells (PBMCs) and polymorphonuclear neutrophils (PMNs) from 31 dogs with atopic dermatitis (AD). The variables assayed included chemiluminescence, acid hydrolase enzyme concentrations, leukotriene B(4) (LTB(4)) production and complement C3 conversion. The results were compared to those derived from a population of clinically healthy dogs. Dogs with AD exhibited a significant increase in median LTB(4) production in PMNs compared to controls (0.94 versus 0.00 ng/10(6) cells; PPBMC fraction - 0.42 versus 0.25 mU/10(6) cells; PPBMC fraction - 0.52 versus 0.27 mU/10(6) cells; P0.05). However, the median time taken to reach maximum chemiluminescence was significantly shorter in the PMN fraction of dogs with AD (7.00 versus 10.00 min; Pdogs had a significant increase in the median percentage conversion of complement C3 to C3b (66.0 versus 57.3%; Pdogs with AD. The role of LTB(4) in the pathogenesis of canine AD and the potential efficacy of leukotriene antagonists in the treatment of this disorder warrant further investigation. PMID:16427587

  20. Involvement of a Natural Fusion of a Cytochrome P450 and a Hydrolase in Mycophenolic Acid Biosynthesis

    Hansen, Bjarne Gram; Mnich, Ewelina; Nielsen, Kristian Fog; Nielsen, Jakob Blæsbjerg; Nielsen, Morten Thrane; Mortensen, Uffe Hasbro; Larsen, Thomas Ostenfeld; Patil, Kiran Raosaheb

    2012-01-01

    Mycophenolic acid (MPA) is a fungal secondary metabolite and the active component in several immunosuppressive pharmaceuticals. The gene cluster coding for the MPA biosynthetic pathway has recently been discovered in Penicillium brevicompactum, demonstrating that the first step is catalyzed by MpaC, a polyketide synthase producing 5-methylorsellinic acid (5-MOA). However, the biochemical role of the enzymes encoded by the remaining genes in the MPA gene cluster is still unknown. Based on bioi...

  1. Hydrogen abstraction reactions by amide electron adducts

    Electron reactions with a number of peptide model compounds (amides and N-acetylamino acids) in aqueous glasses at low temperature have been investigated using ESR spectroscopy. The radicals produced by electron attachment to amides, RC(OD)NDR', are found to act as hydrogen abstracting agents. For example, the propionamide electron adduct is found to abstract from its parent propionamide. Electron adducts of other amides investigated show similar behavior except for acetamide electron adduct which does not abstract from its parent compound, but does abstract from other amides. The tendency toward abstraction for amide electron adducts are compared to electron adducts of several carboxylic acids, ketones, aldehydes and esters. The comparison suggests the hydrogen abstraction tendency of the various deuterated electron adducts (DEAs) to be in the following order: aldehyde DEA > acid DEA = approximately ester DEA > ketone DEA > amide DEA. In basic glasses the hydrogen abstraction ability of the amide electron adducts is maintained until the concentration of base is increased sufficiently to convert the DEA to its anionic form, RC(O-)ND2. In this form the hydrogen abstracting ability of the radical is greatly diminished. Similar results were found for the ester and carboxylic acid DEA's tested. (author)

  2. Human α/β hydrolase domain containing 10 (ABHD10) is responsible enzyme for deglucuronidation of mycophenolic acid acyl-glucuronide in liver.

    Iwamura, Atsushi; Fukami, Tatsuki; Higuchi, Ryota; Nakajima, Miki; Yokoi, Tsuyoshi

    2012-03-16

    Mycophenolic acid (MPA), the active metabolite of the immunosuppressant mycophenolate mofetil (MMF), is primarily metabolized by glucuronidation to a phenolic glucuronide (MPAG) and an acyl glucuronide (AcMPAG). It is known that AcMPAG, which may be an immunotoxic metabolite, is deglucuronidated in human liver. However, it has been reported that recombinant β-glucuronidase does not catalyze this reaction. AcMPAG deglucuronidation activity was detected in both human liver cytosol (HLC) and microsomes (HLM). In this study, the enzyme responsible for AcMPAG deglucuronidation was identified by purification from HLC with column chromatographic purification steps. The purified enzyme was identified as α/β hydrolase domain containing 10 (ABHD10) by amino acid sequence analysis. Recombinant ABHD10 expressed in Sf9 cells efficiently deglucuronidated AcMPAG with a K(m) value of 100.7 ± 10.2 μM, which was similar to those in HLM, HLC, and human liver homogenates (HLH). Immunoblot analysis revealed ABHD10 protein expression in both HLC and HLM. The AcMPAG deglucuronidation by recombinant ABHD10, HLC, and HLH were potently inhibited by AgNO(3), CdCl(2), CuCl(2), PMSF, bis-p-nitrophenylphosphate, and DTNB. The CL(int) value of AcMPAG formation from MPA, which was catalyzed by human UGT2B7, in HLH was increased by 1.8-fold in the presence of PMSF. Thus, human ABHD10 would affect the formation of AcMPAG, the immunotoxic metabolite. PMID:22294686

  3. Synthesis of Caffeic Acid Amides Bearing 2,3,4,5-Tetra-hydrobenzo[b][1,4]dioxocine Moieties and Their Biological Evaluation as Antitumor Agents

    Ji-Wen Yuan

    2014-06-01

    Full Text Available A series of caffeic acid amides D1-D17 bearing 2,3,4,5-tetrahydrobenzo-[b][1,4]dioxocine units has been synthesized and their biological activities evaluated for potential antiproliferative and EGFR inhibitory activity. Of all the compounds studied, compound D9 showed the most potent inhibitory activity (IC50 = 0.79 μM for HepG2 and IC50 = 0.36 μM for EGFR. The structures of compounds were confirmed by 1H-NMR, ESI-MS and elemental analysis. Among all, the structure of compound D9 ((E-N-(4-ethoxyphenyl-3-(2,3,4,5-tetrahydrobenzo[b][1,4]dioxocin-8-ylacrylamide was also determined by single-crystal X-ray diffraction analysis. Compound D9 was found to be a potential antitumor agent according to biological activity, molecular docking, apoptosis assay and inhibition of HepG2.

  4. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic Acid Amides

    Shijie Du

    2015-05-01

    Full Text Available A series of novel 3-(difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-ylphenyl-3-(difluoro-methyl-1-methyl-1H-pyrazole-4-carboxamide (9m exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  5. Synthesis of Racemic Bis[2-(6-fluoro-2-chromanyl)-2-hydroxyethyl]-amine Methanesulfonic Acid Salt Using Lithium Aluminum Amide as a Promoter in Regioselective Ring Opening of Epoxide

    Yun Xu YANG; Nai Xing WANG; Ya Lan XING; Wu Wei WANG; Jia ZHAO; Gui Xia WANG; Shi TANG

    2005-01-01

    Lithium aluminium amide [LiAl(NHR)4] 5 obtained by treating the primary amine 4 with LiAlH4 could promote the ring opening of epoxide 2 and led to high regioselective product of racemic bis[2-(6-fluoro-2-chromanyl)-2-hydroxyethyl]amine methanesulfonic acid salt 7.

  6. Hydrolase-catalyzed synthesis of polyamides and polyester amides

    Stavila, Erythrina

    2014-01-01

    De ontwikkeling van enzymatische polymerisaties duurt al tientallen jaren voort. Er zijn verschillende onderzoeken gedaan op het gebied van enzymatische synthese van polyesters, polycarbonaten, polysaccharides, polypeptides en polyamides, en een aantal hebben reeds industriële toepassing gevonden. L

  7. Involvement of a Natural Fusion of a Cytochrome P450 and a Hydrolase in Mycophenolic Acid Biosynthesis

    Hansen, Bjarne Gram; Mnich, Ewelina; Nielsen, Kristian Fog;

    2012-01-01

    Mycophenolic acid (MPA) is a fungal secondary metabolite and the active component in several immunosuppressive pharmaceuticals. The gene cluster coding for the MPA biosynthetic pathway has recently been discovered in Penicillium brevicompactum, demonstrating that the first step is catalyzed by Mp....... Overall, the chimeric enzyme MpaDE provides insight into the genetic organization of the MPA biosynthesis pathway.......DNA prepared from the extracted RNA. Heterologous coexpression of mpaC and the fusion gene mpaDE in the MPA-nonproducer Aspergillus nidulans resulted in the production of 5,7-dihydroxy-4-methylphthalide (DHMP), the second intermediate in MPA biosynthesis. Analysis of the strain coexpressing mpaC and the mpa...

  8. Valpromide inhibits human epoxide hydrolase.

    Pacifici, G. M.; Franchi, M; Bencini, C; Rane, A

    1986-01-01

    The effect of antipileptic drug valpromide (VPM) on the activity of epoxide hydrolase was studied in human adult and foetal liver, kidneys, lungs, intestine and in placenta. The activity of the epoxide hydrolase was measured with both styrene oxide and benzo(a)pyrene-4,5-oxide as substrates. VPM inhibited the epoxide hydrolase obtained from all organs studied. The degree of inhibition was independent of the substrate used. A lowering of the epoxide hydrolase activity by 50% was observed when ...

  9. Effect of propane-2-sulfonic acid octadec-9-enyl-amide on the expression of adhesion molecules in human umbilical vein endothelial cells.

    Chen, Cai-Xia; Yang, Li-Chao; Xu, Xu-Dong; Wei, Xiao; Gai, Ya-Ting; Peng, Lu; Guo, Han; Hao-Zhou; Wang, Yi-Qing; Jin, Xin

    2015-06-01

    Oleoylethanolamide (OEA), an endogenous agonist of PPARα, has been reported to have anti-atherosclerotic properties. However, OEA can be enzymatically hydrolyzed to oleic acid and ethanolamine and, thus, is not expected to be orally active. In the present study, we designed and synthesized an OEA analog, propane-2-sulfonic acid octadec-9-enyl-amide (N15), which is resistant to enzymatic hydrolysis. The purpose of this study was to investigate the effects of N15 on the expression of adhesion molecules in human umbilical vein endothelial cells (HUVECs). The results showed that N15 inhibited TNFα-induced production of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 and the adhesion of monocytes to TNFα-induced HUVECs. Furthermore, the protective effect of N15 on inflammation is dependent upon a PPAR-α/γ-mediated mechanism. In conclusion, N15 protects against TNFα-induced vascular endothelial inflammation. This anti-inflammatory effect of N15 is dependent on PPAR-α/γ dual targets. PMID:25797284

  10. Hydrolases of the ILR1-like family of Arabidopsis thaliana modulate auxin response by regulating auxin homeostasis in the endoplasmic reticulum.

    Sanchez Carranza, Ana Paula; Singh, Aparajita; Steinberger, Karoline; Panigrahi, Kishore; Palme, Klaus; Dovzhenko, Alexander; Dal Bosco, Cristina

    2016-01-01

    Amide-linked conjugates of indole-3-acetic acid (IAA) have been identified in most plant species. They function in storage, inactivation or inhibition of the growth regulator auxin. We investigated how the major known endogenous amide-linked IAA conjugates with auxin-like activity act in auxin signaling and what role ILR1-like proteins play in this process in Arabidopsis. We used a genetically encoded auxin sensor to show that IAA-Leu, IAA-Ala and IAA-Phe act through the TIR1-dependent signaling pathway. Furthermore, by using the sensor as a free IAA reporter, we followed conjugate hydrolysis mediated by ILR1, ILL2 and IAR3 in plant cells and correlated the activity of the hydrolases with a modulation of auxin response. The conjugate preferences that we observed are in agreement with available in vitro data for ILR1. Moreover, we identified IAA-Leu as an additional substrate for IAR3 and showed that ILL2 has a more moderate kinetic performance than observed in vitro. Finally, we proved that IAR3, ILL2 and ILR1 reside in the endoplasmic reticulum, indicating that in this compartment the hydrolases regulate the rates of amido-IAA hydrolysis which results in activation of auxin signaling. PMID:27063913

  11. A 2:1 co-crystal of p-nitro-benzoic acid and N,N'-bis-(pyridin-3-ylmeth-yl)ethanedi-amide: crystal structure and Hirshfeld surface analysis.

    Syed, Sabrina; Halim, Siti Nadiah Abdul; Jotani, Mukesh M; Tiekink, Edward R T

    2016-01-01

    The title 2:1 co-crystal, 2C7H5NO4·C14H14N4O2, in which the complete di-amide mol-ecule is generated by crystallographic inversion symmetry, features a three-mol-ecule aggregate sustained by hydroxyl-O-H⋯N(pyrid-yl) hydrogen bonds. The p-nitro-benzoic acid mol-ecule is non-planar, exhibiting twists of both the carb-oxy-lic acid and nitro groups, which form dihedral angles of 10.16 (9) and 4.24 (4)°, respectively, with the benzene ring. The di-amide mol-ecule has a conformation approximating to a Z shape, with the pyridyl rings lying to either side of the central, almost planar di-amide residue (r.m.s. deviation of the eight atoms being 0.025 Å), and forming dihedral angles of 77.22 (6)° with it. In the crystal, three-mol-ecule aggregates are linked into a linear supra-molecular ladder sustained by amide-N-H⋯O(nitro) hydrogen bonds and orientated along [10-4]. The ladders are connected into a double layer via pyridyl- and benzene-C-H⋯O(amide) inter-actions, which, in turn, are connected into a three-dimensional architecture via π-π stacking inter-actions between pyridyl and benzene rings [inter-centroid distance = 3.6947 (8) Å]. An evaluation of the Hirshfeld surfaces confirm the importance of inter-molecular inter-actions involving oxygen atoms as well as the π-π inter-actions. PMID:26870591

  12. [11C]Carbon Monoxide in Palladium- / Selenium-Promoted Carbonylation Reactions : Synthesis of 11C-Imides, Hydrazides, Amides, Carboxylic Acids, Carboxylic Esters, Carbothioates, Ketones and Carbamoyl Compounds

    Karimi, Farhad

    2002-01-01

    [11C]Carbon monoxide in low concentrations has been used in palladium- or seleniummediated carbonylation reactions such as the synthesis of 11C-imides, hydrazides, amides, carboxylic acids, esters, carbothioates, ketones and carbamoyl compounds. In these reactions aryl iodides have been used in most cases. However, less reactive aryl triflate, chloride and bromides were activated using tetrabutylammonium iodide. The reactivities of nucleophiles may have influence on the radiochemical yield of...

  13. On complex compounds of molybdenum(5) with nicotinic amide, isonicotinic acid hydrazide and some of its derivatives

    Oxychloride complexes of molybdenum (5) with polyfunctional ligands (L), namely with nicotinamide (NA), isonicotinic acid hydrazide (INH) and its derivatives (ftivazide, saluzide and larusan) have been synthesized and investigated. In ethanol all the ligands independently of their molar ratio form with MoCl5 a non-electrolite compound MoOCl3xL2. Infrared spectra of the complexes suggest that in Mo(5) complexeS with NA and INH the central atom is bound through the pyridine nitrogen, whereas in the complexes with INH derivatives it is bound throught the carbonyl group oxygen

  14. Synthesis of structurally defined scaffolds for bivalent ligand display based on glucuronic acid anilides. The degree of tertiary amide isomerism and folding depends on the configuration of a glycosyl azide.

    Tosin, Manuela; Murphy, Paul V

    2005-05-13

    [structures: see text] Syntheses and structural analyses of bivalent carbohydrates based on anilides of glucuronic acid are described. Secondary anilides predominantly adopted the Z-anti structure; there is also evidence for population of the Z-syn isomer. Bivalent tertiary anilides displayed two signal sets in their NMR spectra, consistent with the presence of (i) a major isomer where both amides have E configurations (EE) and (ii) a minor isomer where one amide is E and the other Z (EZ). Qualitative NOE/ROE spectroscopic studies in solution support the proposal that the anti conformation is preferred for E amides. The crystal structure of one bivalent tertiary anilide showed E-anti and E-syn structural isomers; intramolecular carbohydrate-carbohydrate stacking was observed and mediated by carbonyl-pyranose, azide-azide, and pyranose-aromatic interactions. The EE to EZ isomer ratio, or the degree of folding, for tertiary amides, was greatest for a bivalent compound containing two alpha-glycosyl azide groups; this was enhanced in water, suggesting that hydrophobic interactions are partially but not wholly responsible. Computational methods predicted azide-aromatic (N...H-C interaction) and azide-azide interactions for folded isomers. The close contact of the azide and aromatic protons (N...H-C interaction) was observed upon examination of the close packing in the crystal structure of a related monomer. It is proposed that the alpha-azide group is more optimally aligned, compared to the beta-azide, to facilitate interaction and minimize the surface area of the hydrophobic groups exposed to water, and this leads to the increased folding. The alkylation of bivalent secondary anilides induces a switch from Z to E amide that alters the scaffold orientation. The synthesis of a bivalent mannoside, based on a secondary anilide scaffold, for investigation of mannose-binding receptor cross-linking and lattice formation is described. PMID:15876103

  15. A 2:1 co-crystal of 2-methyl-benzoic acid and N,N'-bis-(pyridin-4-ylmeth-yl)ethanedi-amide: crystal structure and Hirshfeld surface analysis.

    Syed, Sabrina; Jotani, Mukesh M; Halim, Siti Nadiah Abdul; Tiekink, Edward R T

    2016-03-01

    The asymmetric unit of the title 2:1 co-crystal, 2C8H8O2·C14H14N4O2, comprises an acid mol-ecule in a general position and half a di-amide mol-ecule, the latter being located about a centre of inversion. In the acid, the carb-oxy-lic acid group is twisted out of the plane of the benzene ring to which it is attached [dihedral angle = 28.51 (8)°] and the carbonyl O atom and methyl group lie approximately to the same side of the mol-ecule [hy-droxy-O-C-C-C(H) torsion angle = -27.92 (17)°]. In the di-amide, the central C4N2O2 core is almost planar (r.m.s. deviation = 0.031 Å), and the pyridyl rings are perpendicular, lying to either side of the central plane [central residue/pyridyl dihedral angle = 88.60 (5)°]. In the mol-ecular packing, three-mol-ecule aggregates are formed via hy-droxy-O-H⋯N(pyrid-yl) hydrogen bonds. These are connected into a supra-molecular layer parallel to (12[Formula: see text]) via amide-N-H⋯O(carbon-yl) hydrogen bonds, as well as methyl-ene-C-H⋯O(amide) inter-actions. Significant π-π inter-actions occur between benzene/benzene, pyrid-yl/benzene and pyrid-yl/pyridyl rings within and between layers to consolidate the three-dimensional packing. PMID:27006815

  16. Therapeutic effect of the endogenous fatty acid amide, palmitoylethanolamide, in rat acute inflammation: inhibition of nitric oxide and cyclo-oxygenase systems

    Costa, Barbara; Conti, Silvia; Giagnoni, Gabriella; Colleoni, Mariapia

    2002-01-01

    The anti-inflammatory activity of the endogenous fatty acid amide palmitoylethanolamide and its relationship to cyclo-oxygenase (COX) activity, nitric oxide (NO) and oxygen free radical production were investigated in the rat model of carrageenan-induced acute paw inflammation and compared with the nonsteroidal anti-inflammatory drug (NSAID) indomethacin. Palmitoylethanolamide (1, 3, 5, 10 mg kg−1; p.o.) and indomethacin (5 mg kg−1; p.o.) were administered daily after the onset of inflammation for three days and the paw oedema was measured daily; 24 h after the last dose (fourth day) the rats were killed and the COX activity and the content of nitrite/nitrate (NO2−/NO3−), malondialdehyde (MDA), endothelial and inducible nitric oxide synthase (eNOS and iNOS) were evaluated in the paw tissues. Palmitoylethanolamide had a curative effect on inflammation, inhibiting the carrageenan-induced oedema in a dose- and time-dependent manner. This effect was not reversed by the selective CB2 receptor antagonist (N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)pyrazole-3 carboxamide) (SR144528), 3 mg kg−1 p.o. On the fourth day after carrageenan injection, COX activity and the level of NO2−/NO3−, eNOS and MDA were increased in the inflamed paw, but iNOS was not present. Palmitoylethanolamide (10 mg kg−1) and indomethacin markedly reduced these increases. Our findings show, for the first time, that palmitoylethanolamide has a curative effect in a model of acute inflammation. The inhibition of COX activity and of NO and free radical production at the site of inflammation might account for this activity. PMID:12359622

  17. Variation of protein backbone amide resonance by electrostatic field

    Sharley, John N

    2015-01-01

    Amide resonance is found to be sensitive to electrostatic field with component parallel or antiparallel the amide C-N bond. This effect is linear and without threshold in the biologically plausible electrostatic field range -0.005 to 0.005 au. Variation of amide resonance varies Resonance Assisted Hydrogen Bonding such as occurs in the hydrogen bonded chains of backbone amides of protein secondary structures such as beta sheet and non-polyproline helix such as alpha helix, varying the stability of the secondary structure. The electrostatic properties including permittivity of amino acid residue sidegroups influence the electrostatic field component parallel or antiparallel the C-N bond of each amide. The significance of this factor relative to other factors in protein folding depends on the magnitude of electrostatic field component parallel or antiparallel the C-N bond of each amide, and preliminary protein-scale calculations of the magnitude of these components suggest this factor warrants investigation in ...

  18. Biodegradable poly(ester amide)s – A remarkable opportunity for the biomedical area: Review on the synthesis, characterization and

    Fonseca, Ana C.; Gil, Maria H.; Simões, Pedro N.

    2014-01-01

    Poly(ester amide)s have emerged in the last years as an important family of biodegradable synthetic polymers. These polymers present both ester and amide linkages in their structure and they gather in the same entity the good degradability of polyesters with the good thermo-mechanical properties of polyamides. Particularly, poly(ester amide)s containing α-amino acids have risen as important materials in the biomedical field. The presence of the α-amino acid contributes to better cell–polymer ...

  19. Conformation-Specific IR and UV Spectroscopy of the Amino Acid Glutamine: Amide-Stacking and Hydrogen Bonding in AN Important Residue in Neurodegenerative Diseases

    Walsh, Patrick S.; Dean, Jacob C.; Zwier, Timothy S.

    2014-06-01

    Glutamine plays an important role in several neurodegenerative diseases including Huntington's disease (HD) and Alzheimer's disease (AD). An intriguing aspect of the structure of glutamine is its incorporation of an amide group in its side chain, thereby opening up the possibility of forming amide-amide H-bonds between the peptide backbone and side chain. In this study the conformational preferences of two capped gluatamines Z(carboxybenzyl)-Glutamine-X (X=OH, NHMe) are studied under jet-cooled conditions in the gas phase in order to unlock the intrinsic structural motifs that are favored by this flexible sidechain. Conformational assignments are made by comparing the hydride stretch ( 3100-3700 cm-1) and amide I and II ( 1400-1800 cm-1) resonant ion-dip infrared spectra with predictions from harmonic frequency calculations. Assigned structures will be compared to previously published results on both natural and unnatural residues. Particular emphasis will be placed on the comparison between glutamine and unconstrained γ-peptides due to the similar three-carbon spacing between backbone and side chain in glutamine to the backbone spacing in γ-peptides. The ability of the glutamine side-chain to form amide stacked conformations will be a main focus, along with the prevalence of extended backbone type structures. W. H. James, III, C W. Müller, E. G. Buchanan, M. G. D. Nix, L. Guo, L. Roskop, M. S. Gordon, L. V. Slipchenko, S. H. Gellman, and T. S. Zwier, J. Am. Chem. Soc., 2009, 131(40), 14243-14245.

  20. Backbone amide linker strategy

    Shelton, Anne Pernille Tofteng; Jensen, Knud Jørgen

    2013-01-01

    In the backbone amide linker (BAL) strategy, the peptide is anchored not at the C-terminus but through a backbone amide, which leaves the C-terminal available for various modifications. This is thus a very general strategy for the introduction of C-terminal modifications. The BAL strategy was...... assemble the final peptide. One useful application of this strategy is in the synthesis of C-terminal peptide aldehydes. The C-terminal aldehyde is masked as an acetal during synthesis and then conveniently demasked in the final cleavage step to generate the free aldehyde. Another application is in the...

  1. Microwave-assisted synthesis and characterization of camphoric acid chitosan amide%樟脑酸酰化壳聚糖的微波合成及性能表征

    刘振明; 杨艳忠; 李静宇; 谢磊; 杨盛春

    2012-01-01

    以壳聚糖和樟脑酸为原料,在微波辐射下合成了一种新型壳聚糖衍生物——樟脑酸酰化壳聚糖,通过红外(FT-IR)、核磁(1H-NMR)、X-射线衍射(XRD)和热失重(TG)等测试手段对产物结构和性能进行了表征.结果表明樟脑酸通过酰胺键与壳聚糖结合,X-射线结果表明樟脑酸酰化壳聚糖的晶体结构发生了很大的改变,TG分析表明其热稳定性好于壳聚糖.%A new type chitosan derivative,camphoric acid chitosan amide, was synthesized by using of chitosan and camphoric acid as raw materials under microwave irradiation. The chemical structures and properties of the target product were investigated by fourier transform infrared (FT-IR), proton nuclear magnetic resonance spectra CH-NMR), thermogravimetric analyses (TG),and X-ray diffraction (XRD)measurements. The results showed that the camphoric acid is bonded with chitosan by amide-bond. The XRD pattern of product is signicantly different from the crystalline structure of chitosan. TG result demonstrated that thermal stability of the product is better than that of chitosan.

  2. A New Derivative of Valproic Acid Amide Possesses a Broad-spectrum Antiseizure Profile and Unique Activity Against Status Epilepticus and Organophosphate Neuronal Damage

    White, H. Steve; Alex, Anitha B.; Pollock, Amanda; Hen, Naama; Shekh-Ahmad, Tawfeeq; Wilcox, Karen S.; McDonough, John H.; Stables, James P.; Kaufmann, Dan; Yagen, Boris; Bialer, Meir

    2011-01-01

    Summary Purpose sec-Butyl-propylacetamide (SPD) is a one-carbon homologue of valnoctamide (VCD), a CNS-active amide derivative of valproic acid (VPA) currently in phase II clinical trials. The current study evaluated the anticonvulsant activity of SPD in a battery of rodent seizure and epilepsy models and assessed its efficacy in rat and guinea pig models of status epilepticus (SE) and neuroprotection in an organotypic hippocampal slice model of excitotoxic cell death. Methods SPD’s anticonvulsant activity was evaluated in several rodent seizure and epilepsy models including: maximal electroshock (MES), 6Hz psychomotor, subcutaneous (s.c.) metrazol-, s.c., picrotoxin, s.c. bicuculline, audiogenic and corneal and hippocampal kindled seizures following intraperitoneal administration. Results obtained with SPD are discussed in relationship to those obtained with VPA and VCD. SPD was also evaluated for its ability to block benzodiazepine-resistant SE induced by pilocarpine (rats) and soman (rats and guinea pigs) following intraperitoneal administration. SPD was tested for its ability to block excitotoxic cell death induced by the glutamate agonists N-methyl-D-Aspartate (NMDA) and kainic acid (KA) using organotypic hippocampal slices and SE-induced hippocampal cell death using FluoroJade B staining. The cognitive function of SPD-treated rats that were protected against pilocarpine-induced convulsive SE was examined 10-14 days post SE using the Morris water maze (MWM). The relationship between the pharmacokinetic profile of SPD and its efficacy against soman-induced SE was evaluated in two parallel studies following SPD (60 mg/kg, i.p.) administration in the soman SE rat model. Key Findings SPD was highly effective and displayed a wide protective index (PI=TD50/ED50) in the standardized seizure and epilepsy models employed. SPD’s wide PI values demonstrate that it is effective at doses well below those that produce behavioral impairment. Unlike VCD, SPD also

  3. Tertiary fatty amides as diesel fuel substitutes

    Serdari, Aikaterini; Lois, Euripides; Stournas, Stamoulis [National Technical Univ. of Athens, Dept. of Chemical Engineering, Athens (Greece)

    2000-07-01

    This paper presents experimental results regarding the impact of adding different tertiary amides of fatty acids to mineral diesel fuel; an assessment of the behaviour of these compounds as possible diesel fuel extenders is also included. Measurements of cetane number, cold flow properties (cloud point, pour point and CFPP), density, kinematic viscosity, flash point and distillation temperatures are reported, while initial experiments concerning the effects on particulate emissions are also described. Most of the examined tertiary fatty amides esters have very good performance and they can be easily prepared from fatty acids (biomass). Such compounds or their blends could be used as mineral diesel fuel or even fatty acid methylesters (FAME, biodiesel) substitutes or extenders. (Author)

  4. Peptidyl-urea based inhibitors of soluble epoxide hydrolases

    We prepared a series of amino acid derived cyclohexyl and adamantyl ureas and tested them as inhibitors of the human soluble epoxide hydrolase, and obtained very potent compounds (K(I)=15nM) that are >10-fold more soluble than previously described sEH inhibitors. While our lead compound 2 showed low...

  5. Limonene-1,2-Epoxide Hydrolase from Rhodococcus erythropolis DCL14 Belongs to a Novel Class of Epoxide Hydrolases

    van der Werf, Mariët J.; Overkamp, Karin M; de Bont, Jan A. M.

    1998-01-01

    An epoxide hydrolase from Rhodococcus erythropolis DCL14 catalyzes the hydrolysis of limonene-1,2-epoxide to limonene-1,2-diol. The enzyme is induced when R. erythropolis is grown on monoterpenes, reflecting its role in the limonene degradation pathway of this microorganism. Limonene-1,2-epoxide hydrolase was purified to homogeneity. It is a monomeric cytoplasmic enzyme of 17 kDa, and its N-terminal amino acid sequence was determined. No cofactor was required for activity of this colorless en...

  6. Transcription of the Human Microsomal Epoxide Hydrolase Gene (EPHX1 Is Regulated by PARP-1 and Histone H1.2. Association with Sodium-Dependent Bile Acid Transport.

    Hui Peng

    Full Text Available Microsomal epoxide hydrolase (mEH is a bifunctional protein that plays a central role in the metabolism of numerous xenobiotics as well as mediating the sodium-dependent transport of bile acids into hepatocytes. These compounds are involved in cholesterol homeostasis, lipid digestion, excretion of xenobiotics and the regulation of several nuclear receptors and signaling transduction pathways. Previous studies have demonstrated the critical role of GATA-4, a C/EBPα-NF/Y complex and an HNF-4α/CAR/RXR/PSF complex in the transcriptional regulation of the mEH gene (EPHX1. Studies also identified heterozygous mutations in human EPHX1 that resulted in a 95% decrease in mEH expression levels which was associated with a decrease in bile acid transport and severe hypercholanemia. In the present investigation we demonstrate that EPHX1 transcription is significantly inhibited by two heterozygous mutations observed in the Old Order Amish population that present numerous hypercholanemic subjects in the absence of liver damage suggesting a defect in bile acid transport into the hepatocyte. The identity of the regulatory proteins binding to these sites, established using biotinylated oligonucleotides in conjunction with mass spectrometry was shown to be poly(ADP-ribosepolymerase-1 (PARP-1 bound to the EPHX1 proximal promoter and a linker histone complex, H1.2/Aly, bound to a regulatory intron 1 site. These sites exhibited 71% homology and may represent potential nucleosome positioning domains. The high frequency of the H1.2 site polymorphism in the Amish population results in a potential genetic predisposition to hypercholanemia and in conjunction with our previous studies, further supports the critical role of mEH in mediating bile acid transport into hepatocytes.

  7. Role of soluble epoxide hydrolase in the sex-specific vascular response to cerebral ischemia

    Zhang, Wenri; Iliff, Jeffrey J.; Campbell, Caitlyn J; Wang, Ruikang K.; Hurn, Patricia D.; Alkayed, Nabil J.

    2009-01-01

    Soluble epoxide hydrolase (sEH), a key enzyme in the metabolism of vasodilator eicosanoids called epoxyeicosatrienoic acids (EETs), is sexually dimorphic and suppressed by estrogen. We determined if the sex difference in blood flow during focal cerebral ischemia is linked to sEH. Soluble epoxide hydrolase expression in brain, hydrolase activity in cerebral vessels, and plasma 14,15-dihydroxyeicosatrienoic acid (14,15-DHET) were determined in male and female wild-type (WT) and sEH knockout (sE...

  8. Hydrogen Bonds between Acidic Protons from Alkynes (C–H···O and Amides (N–H···O and Carbonyl Oxygen Atoms as Acceptor Partners

    Pierre Baillargeon

    2014-01-01

    Full Text Available Crystals of tert-butyl (2S-2-(prop-2-yn-1-ylcarbamoylpyrrolidine-1-carboxylate (Boc-L-Pro-NHCH2CCH have been obtained. The title compound crystallizes easily as sharp needles in orthorhombic system, space group P 21 21 21 with a = 9.2890(2, b = 9.7292(2, c = 15.7918(4 Å, V = 1427.18(6 Å3, and Z = 4. The main feature of the structure is the orientation of the carbamate and amide. Their dipoles add up and the molecule displays an electric dipole moment of 5.61 D from B3LYP/6-31G(d calculations. The antiparallel H bonding of amides and the alignment of dipoles induce columnar stacking (the dipole moment along the columnar a axis is 4.46 D for each molecule. The other components across the other axes are, therefore weaker, (3.17 D and 1.23 D along the b and c axes, resp.. The resulting anisotropic columns pack side by side, in an antiparallel fashion mostly by (alkyne CH···O=C (carbamate interactions.

  9. Polyglycine hydrolases secreted by pathogenic fungi

    Pathogens are known to produce proteases that target host defense proteins. Here we describe polyglycine hydrolases, fungal proteases that selectively cleave glycine-glycine peptide bonds within the polyglycine interdomain linker of targeted plant defense chitinases. Polyglycine hydrolases were puri...

  10. Circulating Endocannabinoids and the Polymorphism 385C>A in Fatty Acid Amide Hydrolase (FAAH Gene May Identify the Obesity Phenotype Related to Cardiometabolic Risk: A Study Conducted in a Brazilian Population of Complex Interethnic Admixture.

    Cyro José de Moraes Martins

    Full Text Available The dysregulation of the endocannabinoid system is associated with cardiometabolic complications of obesity. Allelic variants in coding genes for this system components may contribute to differences in the susceptibility to obesity and related health hazards. These data have mostly been shown in Caucasian populations and in severely obese individuals. We investigated a multiethnic Brazilian population to study the relationships among the polymorphism 385C>A in an endocannabinoid degrading enzyme gene (FAAH, endocannabinoid levels and markers of cardiometabolic risk. Fasting plasma levels of endocannabinoids and congeners (anandamide, 2-arachidonoylglycerol, N-oleoylethanolamide and N-palmitoylethanolamide were measured by liquid chromatography-mass spectrometry in 200 apparently healthy individuals of both genders with body mass indices from 22.5 ± 1.8 to 35.9 ± 5.5 kg/m2 (mean ± 1 SD and ages between 18 and 60 years. All were evaluated for anthropometric parameters, blood pressure, metabolic variables, homeostatic model assessment of insulin resistance (HOMA-IR, adiponectin, leptin, C-reactive protein, and genotyping. The endocannabinoid levels increased as a function of obesity and insulin resistance. The homozygous genotype AA was associated with higher levels of anandamide and lower levels of adiponectin versus wild homozygous CC and heterozygotes combined. The levels of anandamide were independent and positively associated with the genotype AA position 385 of FAAH, C-reactive protein levels and body mass index. Our findings provide evidence for an endocannabinoid-related phenotype that may be identified by the combination of circulating anandamide levels with genotyping of the FAAH 385C>A; this phenotype is not exclusive to mono-ethnoracial populations nor to individuals with severe obesity.

  11. Circulating Endocannabinoids and the Polymorphism 385C>A in Fatty Acid Amide Hydrolase (FAAH) Gene May Identify the Obesity Phenotype Related to Cardiometabolic Risk: A Study Conducted in a Brazilian Population of Complex Interethnic Admixture.

    Martins, Cyro José de Moraes; Genelhu, Virginia; Pimentel, Marcia Mattos Gonçalves; Celoria, Bruno Miguel Jorge; Mangia, Rogerio Fabris; Aveta, Teresa; Silvestri, Cristoforo; Di Marzo, Vincenzo; Francischetti, Emilio Antonio

    2015-01-01

    The dysregulation of the endocannabinoid system is associated with cardiometabolic complications of obesity. Allelic variants in coding genes for this system components may contribute to differences in the susceptibility to obesity and related health hazards. These data have mostly been shown in Caucasian populations and in severely obese individuals. We investigated a multiethnic Brazilian population to study the relationships among the polymorphism 385C>A in an endocannabinoid degrading enzyme gene (FAAH), endocannabinoid levels and markers of cardiometabolic risk. Fasting plasma levels of endocannabinoids and congeners (anandamide, 2-arachidonoylglycerol, N-oleoylethanolamide and N-palmitoylethanolamide) were measured by liquid chromatography-mass spectrometry in 200 apparently healthy individuals of both genders with body mass indices from 22.5 ± 1.8 to 35.9 ± 5.5 kg/m2 (mean ± 1 SD) and ages between 18 and 60 years. All were evaluated for anthropometric parameters, blood pressure, metabolic variables, homeostatic model assessment of insulin resistance (HOMA-IR), adiponectin, leptin, C-reactive protein, and genotyping. The endocannabinoid levels increased as a function of obesity and insulin resistance. The homozygous genotype AA was associated with higher levels of anandamide and lower levels of adiponectin versus wild homozygous CC and heterozygotes combined. The levels of anandamide were independent and positively associated with the genotype AA position 385 of FAAH, C-reactive protein levels and body mass index. Our findings provide evidence for an endocannabinoid-related phenotype that may be identified by the combination of circulating anandamide levels with genotyping of the FAAH 385C>A; this phenotype is not exclusive to mono-ethnoracial populations nor to individuals with severe obesity. PMID:26561012

  12. Circulating Endocannabinoids and the Polymorphism 385C>A in Fatty Acid Amide Hydrolase (FAAH) Gene May Identify the Obesity Phenotype Related to Cardiometabolic Risk: A Study Conducted in a Brazilian Population of Complex Interethnic Admixture

    Martins, Cyro José de Moraes; Genelhu, Virginia; Pimentel, Marcia Mattos Gonçalves; Celoria, Bruno Miguel Jorge; Mangia, Rogerio Fabris; Aveta, Teresa; Silvestri, Cristoforo; Di Marzo, Vincenzo; Francischetti, Emilio Antonio

    2015-01-01

    The dysregulation of the endocannabinoid system is associated with cardiometabolic complications of obesity. Allelic variants in coding genes for this system components may contribute to differences in the susceptibility to obesity and related health hazards. These data have mostly been shown in Caucasian populations and in severely obese individuals. We investigated a multiethnic Brazilian population to study the relationships among the polymorphism 385C>A in an endocannabinoid degrading enz...

  13. Fatty Acid Amide Hydrolase (FAAH), Acetylcholinesterase (AChE), and Butyrylcholinesterase (BuChE): Networked Targets for the Development of Carbamates as Potential Anti-Alzheimer's Disease Agents.

    Montanari, Serena; Scalvini, Laura; Bartolini, Manuela; Belluti, Federica; Gobbi, Silvia; Andrisano, Vincenza; Ligresti, Alessia; Di Marzo, Vincenzo; Rivara, Silvia; Mor, Marco; Bisi, Alessandra; Rampa, Angela

    2016-07-14

    The modulation of the endocannabinoid system is emerging as a viable avenue for the treatment of neurodegeneration, being involved in neuroprotective and anti-inflammatory processes. In particular, indirectly enhancing endocannabinoid signaling to therapeutic levels through FAAH inhibition might be beneficial for neurodegenerative disorders such as Alzheimer's disease, effectively preventing or slowing the progression of the disease. Hence, in the search for a more effective treatment for Alzheimer's disease, in this paper, the multitarget-directed ligand paradigm was applied to the design of carbamates able to simultaneously target the recently proposed endocannabinoid system and the classic cholinesterase system, and achieve effective dual FAAH/cholinesterase inhibitors. Among the two series of synthesized compounds, while some derivatives proved to be extremely potent on a single target, compounds 9 and 19 were identified as effective dual FAAH/ChE inhibitors, with well-balanced nanomolar activities. Thus, 9 and 19 might be considered as new promising candidates for Alzheimer's disease treatment. PMID:27309570

  14. Advances in the discovery of N-acylethanolamine acid amidase inhibitors.

    Bandiera, Tiziano; Ponzano, Stefano; Piomelli, Daniele

    2014-08-01

    N-Acylethanolamine acid amidase (NAAA) is a cysteine amidase that hydrolyzes saturated or monounsaturated fatty acid ethanolamides, such as palmitoylethanolamide (PEA) and oleoylethanolamide (OEA). PEA has been shown to exert analgesic and anti-inflammatory effects by engaging peroxisome proliferator-activated receptor-α. Like other fatty acid ethanolamides, PEA is not stored in cells, but produced on demand from cell membrane precursors, and its actions are terminated by intracellular hydrolysis by either fatty acid amide hydrolase or NAAA. Endogenous levels of PEA and OEA have been shown to decrease during inflammation. Modulation of the tissue levels of PEA by inhibition of enzymes responsible for the breakdown of this lipid mediator may represent therefore a new therapeutic strategy for the treatment of pain and inflammation. While a large number of inhibitors of fatty acid amide hydrolase have been discovered, few compounds have been reported to inhibit NAAA activity. Here, we describe the most representative NAAA inhibitors and briefly highlight their pharmacological profile. A recent study has shown that a NAAA inhibitor attenuated heat hyperalgesia and mechanical allodynia caused by local inflammation or nerve damage in animal models of pain and inflammation. This finding encourages further exploration of the pharmacology of NAAA inhibitors. PMID:24798679

  15. Cloning of a Novel Arylamidase Gene from Paracoccus sp. Strain FLN-7 That Hydrolyzes Amide Pesticides

    Zhang, Jun; Yin, Jin-Gang; Hang, Bao-Jian; Cai, Shu; He, Jian; Zhou, Shun-Gui; Li, Shun-Peng

    2012-01-01

    The bacterial isolate Paracoccus sp. strain FLN-7 hydrolyzes amide pesticides such as diflubenzuron, propanil, chlorpropham, and dimethoate through amide bond cleavage. A gene, ampA, encoding a novel arylamidase that catalyzes the amide bond cleavage in the amide pesticides was cloned from the strain. ampA contains a 1,395-bp open reading frame that encodes a 465-amino-acid protein. AmpA was expressed in Escherichia coli BL21 and homogenously purified using Ni-nitrilotriacetic acid affinity c...

  16. Primary structure and catalytic mechanism of the epoxide hydrolase from Agrobacterium radiobacter AD1

    Rink, R; Fennema, M.; Smids, M; Dehmel, U; Janssen, DB

    1997-01-01

    The epoxide hydrolase gene from Agrobacterium radiobacter AD1, a bacterium that is able to grow on epichlorohydrin as the sole carbon source, was cloned by means of the polymerase chain reaction with two degenerate primers based on the N-terminal and C-terminal sequences of the enzyme, The epoxide hydrolase gene coded for a protein of 294 amino acids with a molecular mass of 34 kDa, An identical epoxide hydrolase gene was cloned from chromosomal DNA of the closely related strain A, radiobacte...

  17. [Amides of creatine: perspectives of neuroprotection].

    Vlasov, T D; Chefu, S G; Baĭsa, A E; Leko, M V; Burov, S V; Veselkina, O S

    2011-07-01

    We evaluated the efficacy of derivatives of creatine and amino acids (CrAA) for decreasing cerebral injury in rats with transient middle cerebral artery occlusion (MCAO). Neuroprotective effects of amides of creatine and glycine (CrGlyOEt), phenylalanine (CrPheNH2), thyrosine (CrTyrNH2), and GABA (CrGABAOEt) were investigated. Brain injury was evaluated on day 2 after transient MCAO using a TTC staining of brain slices. Compared with the MCAO control group, all the CrAms showed decreased cerebral injury (p < 0.05). However CrPheNH2, CrTyrNH2, and CrGABAOEt were toxic after intravenous administration and investigated only after intraperitoneal injection. CrGlyOEt did not show any toxicity at dose of 1 mmol/kg. These data evidenced that creatinyl amides can represent promising candidates for the development of new drugs useful in brain ischemia treatment. PMID:21961295

  18. Murine elongation factor 1 alpha (EF-1 alpha) is posttranslationally modified by novel amide-linked ethanolamine-phosphoglycerol moieties. Addition of ethanolamine-phosphoglycerol to specific glutamic acid residues on EF-1 alpha

    Elongation Factor 1 alpha (EF-1 alpha), an important eukaryotic translation factor, transports charged aminoacyl-tRNA from the cytosol to the ribosomes during poly-peptide synthesis. Metabolic radiolabeling with [3H] ethanolamine shows that, in all cells examined, EF-1 alpha is the major radiolabeled protein. Radiolabeled EF-1 alpha has an apparent Mr = 53,000 and a basic isoelectric point. It is cytosolic and does not contain N-linked oligosaccharides. Trypsin digestion of murine EF-1 alpha generated two major [3H]ethanolamine-labeled peptides. Three peptides were sequenced and were identical to two distinct regions of the human EF-1 alpha protein. Blank sequencing cycles coinciding with glutamic acid in the human cDNA-derived sequence were also found to release [3H]ethanolamine, and compositional analysis of these peptides confirmed the presence of glutamic acid. Dansylation analysis demonstrates that the amine group of the ethanolamine is blocked. These results indicate that EF-1 alpha is posttranslationally modified by the covalent attachment of ethanolamine via an amide bond to at least two specific glutamic acid residues (Glu-301 and Glu-374). The hydroxyl group of the attached ethanolamine was shown by mass spectrometry and compositional analysis, to be further modified by the addition of a phosphoglycerol unit. This novel posttranslational modification may represent an important alteration of EF-1 alpha, comparable to the regulatory effects of posttranslational methylation of EF-1 alpha lysine residues

  19. CREST - a large and diverse superfamily of putative transmembrane hydrolases

    Olson Eric N

    2011-07-01

    Full Text Available Abstract Background A number of membrane-spanning proteins possess enzymatic activity and catalyze important reactions involving proteins, lipids or other substrates located within or near lipid bilayers. Alkaline ceramidases are seven-transmembrane proteins that hydrolyze the amide bond in ceramide to form sphingosine. Recently, a group of putative transmembrane receptors called progestin and adipoQ receptors (PAQRs were found to be distantly related to alkaline ceramidases, raising the possibility that they may also function as membrane enzymes. Results Using sensitive similarity search methods, we identified statistically significant sequence similarities among several transmembrane protein families including alkaline ceramidases and PAQRs. They were unified into a large and diverse superfamily of putative membrane-bound hydrolases called CREST (alkaline ceramidase, PAQR receptor, Per1, SID-1 and TMEM8. The CREST superfamily embraces a plethora of cellular functions and biochemical activities, including putative lipid-modifying enzymes such as ceramidases and the Per1 family of putative phospholipases involved in lipid remodeling of GPI-anchored proteins, putative hormone receptors, bacterial hemolysins, the TMEM8 family of putative tumor suppressors, and the SID-1 family of putative double-stranded RNA transporters involved in RNA interference. Extensive similarity searches and clustering analysis also revealed several groups of proteins with unknown function in the CREST superfamily. Members of the CREST superfamily share seven predicted core transmembrane segments with several conserved sequence motifs. Conclusions Universal conservation of a set of histidine and aspartate residues across all groups in the CREST superfamily, coupled with independent discoveries of hydrolase activities in alkaline ceramidases and the Per1 family as well as results from previous mutational studies of Per1, suggests that the majority of CREST members are

  20. Detoxification Strategy of Epoxide Hydrolase

    Arand, Michael; Cronin, Annette; Hengstler, Jan G.; Herrero Plana, Maria Elena; Lohmann, Matthias; Oesch, Franz

    2003-01-01

    The human microsomal epoxide hydrolase, a single enzyme, has to detoxify a broad range of structurally diverse, potentially genotoxic epoxides that are formed in the course of xenobiotic metabolism. The enzyme has developed a unique strategy to combine a broad substrate specificity with a high detoxification efficacy, by immediately trapping the reactive compounds as covalent intermediates and by being expressed at high levels for high trapping capacity. Computer simulation and experimental d...

  1. Tandem dissolution of UO3 in amide-based acidic ionic liquid and in situ electrodeposition of UO2 with regeneration of the ionic liquid: a closed cycle.

    Wanigasekara, Eranda; Freiderich, John W; Sun, Xiao-Guang; Meisner, Roberta A; Luo, Huimin; Delmau, Lætitia H; Dai, Sheng; Moyer, Bruce A

    2016-06-21

    A closed cycle is demonstrated for the tandem dissolution and electroreduction of UO3 to UO2 with regeneration of the acidic ionic liquid. The dissolution is achieved by use of the acidic ionic liquid [DMAH][NTf2] in [EMIM][NTf2] serving as the diluent. A sequential dissolution, electroreduction, and regeneration cycle is presented. PMID:27255672

  2. Possible evidence of amide bond formation between sinapinic acid and lysine-containing bacterial proteins by matrix-assisted laser desorption/ionization (MALDI) at 355 nm

    We previously reported the apparent formation of matrix adducts of 3,5-dimethoxy-4-hydroxy-cinnamic acid (sinapinic acid or SA) via covalent attachment to disulfide bond-containing proteins (HdeA, HdeB and YbgS) from bacterial cell lysates ionized by matrix-assisted laser desorption/ionization (MALD...

  3. Les lipases sont des hydrolases atypiques : principales caractéristiques et applications

    Fickers P.

    2008-01-01

    Full Text Available ipases are atypical hydrolases: principal characteristics and applications. Due to their kinetic and substrate specificities, triacylglycerol acyl-hydrolases or lipases are atypical enzymes. In function of their microenvironment, lipases are able to act as hydrolases in aqueous solution or as biocatalysts in organic synthesis. As hydrolases, they are responsible of the triglycerids catabolism into fatty acids and glycerol. In many organisms, this reaction plays a major role in the fat and lipid metabolism. In addition, lipases are also able to hydrolyse phospholipids and cholesterol esters. In organic solvent, lipases could catalyse reactions such as esterifications, acidolysis or alcoolysis with enantio-, regio- and chimioselectivity. Lipases form a mixed class of enzyme due to their animal, vegetal or microbial origins. All those properties led to the development of many applications in the food and chemical industries but also in the medical and therapeutic field.

  4. The ortho backbone amide linker (o-BAL) is an easily prepared and highly acid-labile handle for solid-phase synthesis

    Boas, Ulrik; Brask, Jesper; Christensen, J.B.;

    2002-01-01

    , followed by purification through steam distillation, Cleavage studies of Leu-enkephalin anchored to either o-BAL or p-BAL handles revealed that both handles were surprisingly acid-labile and released the peptide with dilute TFA (5% and even 1% TFA in CH2Cl2). This useful property allowed the synthesis of...

  5. Ability of Serum Glial Fibrillary Acidic Protein, Ubiquitin C-Terminal Hydrolase-L1, and S100B To Differentiate Normal and Abnormal Head Computed Tomography Findings in Patients with Suspected Mild or Moderate Traumatic Brain Injury.

    Welch, Robert D; Ayaz, Syed I; Lewis, Lawrence M; Unden, Johan; Chen, James Y; Mika, Valerie H; Saville, Ben; Tyndall, Joseph A; Nash, Marshall; Buki, Andras; Barzo, Pal; Hack, Dallas; Tortella, Frank C; Schmid, Kara; Hayes, Ronald L; Vossough, Arastoo; Sweriduk, Stephen T; Bazarian, Jeffrey J

    2016-01-15

    Head computed tomography (CT) imaging is still a commonly obtained diagnostic test for patients with minor head injury despite availability of clinical decision rules to guide imaging use and recommendations to reduce radiation exposure resulting from unnecessary imaging. This prospective multicenter observational study of 251 patients with suspected mild to moderate traumatic brain injury (TBI) evaluated three serum biomarkers' (glial fibrillary acidic protein [GFAP], ubiquitin C-terminal hydrolase-L1 [UCH-L1] and S100B measured within 6 h of injury) ability to differentiate CT negative and CT positive findings. Of the 251 patients, 60.2% were male and 225 (89.6%) had a presenting Glasgow Coma Scale score of 15. A positive head CT (intracranial injury) was found in 36 (14.3%). UCH-L1 was 100% sensitive and 39% specific at a cutoff value >40 pg/mL. To retain 100% sensitivity, GFAP was 0% specific (cutoff value 0 pg/mL) and S100B had a specificity of only 2% (cutoff value 30 pg/mL). All three biomarkers had similar values for areas under the receiver operator characteristic curve: 0.79 (95% confidence interval; 0.70-0.88) for GFAP, 0.80 (0.71-0.89) for UCH-L1, and 0.75 (0.65-0.85) for S100B. Neither GFAP nor UCH-L1 curve values differed significantly from S100B (p = 0.21 and p = 0.77, respectively). In our patient cohort, UCH-L1 outperformed GFAP and S100B when the goal was to reduce CT use without sacrificing sensitivity. UCH-L1 values <40 pg/mL could potentially have aided in eliminating 83 of the 215 negative CT scans. These results require replication in other studies before the test is used in actual clinical practice. PMID:26467555

  6. Design and synthesis of isoniazide mimetic conjugated with DTPA, potential ligand of novel radiopharmaceutical and contrast agent for medical imaging, bis (amide) of diethylenetriaminepentaacetic acid: DTPA-Bis(INH)

    The structure of isonicotinic acid hydrazide (INH) was coupled to diethylenetriaminepentaacetic acid (DTPA) via amide linkage. The overall yield of three steps synthesis starting from DTPA is above 80%. In particular, complexation of DTPA moiety with 99mTc showed excellent results as the metallopharmaceutical for medical imaging. The main objective of the present research was to develop a novel INH derivative based on DTPA, which forms stable complexes with most of the lanthanides and transition metals in the periodic table. A second objective was to introduce a chelating group without compromising the biological activity of the anti-infective drug for the diagnosis of infection using nuclear medicine. The DTPA-Bis(INH) was synthesized in high yield using a simple synthetic procedure and was characterized using mass spectroscopy in ESI positive mode ([M+H+] was found to be 632.2). Moreover, the complex with the DTPA-Bis(INH) is reflected in increased kinetic ability of the stabilized 99mTc complex compared with the unmodified INH. The complex was successfully labelled with the 99mTc radionuclide with more than 95% labelling efficiency. Radiochemical purity was ascertained chromatographically (ITLC and C18 RP chromatography) using different solvent systems. Blood kinetics in rabbits and biodistribution in mice was studied. Blood kinetics showed rapid first pass clearance with a biological half-life, t1/2 (F), of 11 min. The ability of DTPA-Bis(INH) to target the infection site in vivo was assessed in gamma scintigraphic studies of normal rabbit and a rabbit with induced infections. From the present work it can be concluded that the radiolabelled DTPABis( INH) accumulates at the site of infection. (author)

  7. [Effect of anti-arteriosclerosis diet, containing soya protein isolate and omega-3 polyunsaturated fatty acids on the activity of mononuclear and platelet lysosomal hydrolases in patients with hypertension and ischemic heart disease].

    Samsonov, M A; Pogozhaeva, A V; Vasilév, A V; Bogdanova, S N; Pokrovskaia, G R; Varsanovich, E A; Orlova, L A

    1993-01-01

    In response to antiatherosclerosis dietotherapy containing 20 g of ichthyenic oil, coronary and hypertensive subjects showed lowered serum levels of cholesterol, triglycerides and atherogenic index, elevated HDLP cholesterol and corrected immunochemical shifts. SPI-containing diet resulted in changes of CIC IgM levels only. Shifts in the activity of mononuclear and platelet lysosomal hydrolases which occurred in the above patients due to relevant diets reflect higher sensitivity of this parameter in assessment of the dietotherapy effectiveness. PMID:7975402

  8. Endocannabinoid and cannabinoid-like fatty acid amide levels correlate with pain-related symptoms in patients with IBS-D and IBS-C: a pilot study.

    Jakub Fichna

    Full Text Available AIMS: Irritable bowel syndrome (IBS is a functional gastrointestinal (GI disorder, associated with alterations of bowel function, abdominal pain and other symptoms related to the GI tract. Recently the endogenous cannabinoid system (ECS was shown to be involved in the physiological and pathophysiological control of the GI function. The aim of this pilot study was to investigate whether IBS defining symptoms correlate with changes in endocannabinoids or cannabinoid like fatty acid levels in IBS patients. METHODS: AEA, 2-AG, OEA and PEA plasma levels were determined in diarrhoea-predominant (IBS-D and constipation-predominant (IBS-C patients and were compared to healthy subjects, following the establishment of correlations between biolipid contents and disease symptoms. FAAH mRNA levels were evaluated in colonic biopsies from IBS-D and IBS-C patients and matched controls. RESULTS: Patients with IBS-D had higher levels of 2AG and lower levels of OEA and PEA. In contrast, patients with IBS-C had higher levels of OEA. Multivariate analysis found that lower PEA levels are associated with cramping abdominal pain. FAAH mRNA levels were lower in patients with IBS-C. CONCLUSION: IBS subtypes and their symptoms show distinct alterations of endocannabinoid and endocannabinoid-like fatty acid levels. These changes may partially result from reduced FAAH expression. The here reported changes support the notion that the ECS is involved in the pathophysiology of IBS and the development of IBS symptoms.

  9. On DABAL-Me₃ promoted formation of amides

    Dubois, Nathalie; Glynn, Daniel; McInally, Thomas; Rhodes, Barrie; Woodward, Simon; Irvine, Derek; Dodds, Chris

    2013-01-01

    The range and utility of DABAL-Me3 couplings of methyl esters and free carboxylic acids with primary and secondary amines under a variety of conditions (reflux, sealed tube, microwave) has been compared for a significant range of coupling partners of relevance to the preparation of amides of interest in pharmaceutical chemistry. Commercial microwave reactors promote the fastest couplings and allow the use of significantly sterically hindered amines (primary and secondary) and carboxylic acids...

  10. Cellular Inhibition of Checkpoint Kinase 2 (Chk2) and Potentiation of Camptothecins and Radiation by the Novel Chk2 Inhibitor PV1019 [7-Nitro-1H-indole-2-carboxylic acid {4-[1-(guanidinohydrazone)-ethyl]-phenyl}-amide

    Jobson, Andrew G.; Lountos, George T.; Lorenzi, Philip L.; Llamas, Jenny; Connelly, John; Cerna, David; Tropea, Joseph E.; Onda, Akikazu; Zoppoli, Gabriele; Kondapaka, Sudhir; Zhang, Guangtao; Caplen, Natasha J.; Cardellina, II, John H.; Yoo, Stephen S.; Monks, Anne; Self, Christopher; Waugh, David S.; Shoemaker, Robert H.; Pommier, Yves; (NIH)

    2010-04-05

    Chk2 is a checkpoint kinase involved in the ataxia telangiectasia mutated pathway, which is activated by genomic instability and DNA damage, leading to either cell death (apoptosis) or cell cycle arrest. Chk2 provides an unexplored therapeutic target against cancer cells. We recently reported 4,4'-diacetyldiphenylurea-bis(guanylhydrazone) (NSC 109555) as a novel chemotype Chk2 inhibitor. We have now synthesized a derivative of NSC 109555, PV1019 (NSC 744039) [7-nitro-1H-indole-2-carboxylic acid {l_brace}4-[1-(guanidinohydrazone)-ethyl]-phenyl{r_brace}-amide], which is a selective submicromolar inhibitor of Chk2 in vitro. The cocrystal structure of PV1019 bound in the ATP binding pocket of Chk2 confirmed enzymatic/biochemical observations that PV1019 acts as a competitive inhibitor of Chk2 with respect to ATP. PV1019 was found to inhibit Chk2 in cells. It inhibits Chk2 autophosphorylation (which represents the cellular kinase activation of Chk2), Cdc25C phosphorylation, and HDMX degradation in response to DNA damage. PV1019 also protects normal mouse thymocytes against ionizing radiation-induced apoptosis, and it shows synergistic antiproliferative activity with topotecan, camptothecin, and radiation in human tumor cell lines. We also show that PV1019 and Chk2 small interfering RNAs can exert antiproliferative activity themselves in the cancer cells with high Chk2 expression in the NCI-60 screen. These data indicate that PV1019 is a potent and selective inhibitor of Chk2 with chemotherapeutic and radiosensitization potential.

  11. Polymer amide as an early topology.

    Julie E M McGeoch

    Full Text Available Hydrophobic polymer amide (HPA could have been one of the first normal density materials to accrete in space. We present ab initio calculations of the energetics of amino acid polymerization via gas phase collisions. The initial hydrogen-bonded di-peptide is sufficiently stable to proceed in many cases via a transition state into a di-peptide with an associated bound water molecule of condensation. The energetics of polymerization are only favorable when the water remains bound. Further polymerization leads to a hydrophobic surface that is phase-separated from, but hydrogen bonded to, a small bulk water complex. The kinetics of the collision and subsequent polymerization are discussed for the low-density conditions of a molecular cloud. This polymer in the gas phase has the properties to make a topology, viz. hydrophobicity allowing phase separation from bulk water, capability to withstand large temperature ranges, versatility of form and charge separation. Its flexible tetrahedral carbon atoms that alternate with more rigid amide groups allow it to deform and reform in hazardous conditions and its density of hydrogen bonds provides adhesion that would support accretion to it of silicon and metal elements to form a stellar dust material.

  12. Generation of a novel monoclonal antibody that recognizes the alpha (α)-amidated isoform of a valine residue

    Antón Palma, Benito; Leff Gelman, Philippe; Medecigo Ríos, Mayra; Calva Nieves, Juan Carlos; Acevedo Ortuño, Rodolfo; Matus Ortega, Maura Epifanía; Hernández Calderón, Jorge Alberto; Hernández Miramontes, Ricardo; Flores Zamora, Anabel; Salazar Juárez, Alberto

    2015-01-01

    Background Alpha (α)-amidation of peptides is a mechanism required for the conversion of prohormones into functional peptide sequences that display biological activities, receptor recognition and signal transduction on target cells. Alpha (α)-amidation occurs in almost all species and amino acids identified in nature. C-terminal valine amide neuropeptides constitute the smallest group of functional peptide compounds identified in neurosecretory structures in vertebrate and invertebrate specie...

  13. Synthesis of Glycosyl Amides Using Selenocarboxylates as Traceless Reagents for Amide Bond Formation.

    Silva, Luana; Affeldt, Ricardo F; Lüdtke, Diogo S

    2016-07-01

    Carbohydrate-derived amides were successfully prepared in good yields from a broad range of substrates, including furanosyl and pyranosyl derivatives. The methodology successfully relied on the in situ generation of lithium selenocarboxylates from Se/LiEt3BH and acyl chlorides or carboxylic acids and their reaction with sugar azides. A key aspect of the present protocol is that we start from elemental selenium; isolation and handling of all reactive and sensitive selenium-containing intermediates is avoided, therefore providing the selenocarboxylate the status of a traceless reagent. PMID:27275515

  14. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

    2013-02-01

    Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay. PMID:23313636

  15. The Wood Rot Ascomycete Xylaria polymorpha Produces a Novel GH78 Glycoside Hydrolase That Exhibits α-l-Rhamnosidase and Feruloyl Esterase Activities and Releases Hydroxycinnamic Acids from Lignocelluloses

    Nghi, Do Huu; Bittner, Britta; Kellner, Harald; Jehmlich, Nico; Ullrich, René; Pecyna, Marek J.; Nousiainen, Paula; Sipilä, Jussi; Huong, Le Mai; Hofrichter, Martin; Liers, Christiane

    2012-01-01

    Soft rot (type II) fungi belonging to the family Xylariaceae are known to substantially degrade hardwood by means of their poorly understood lignocellulolytic system, which comprises various hydrolases, including feruloyl esterases and laccase. In the present study, several members of the Xylariaceae were found to exhibit high feruloyl esterase activity during growth on lignocellulosic materials such as wheat straw (up to 1,675 mU g−1) or beech wood (up to 80 mU g−1). Following the ester-clea...

  16. Design and synthesis of isoniazide mimetic conjugated with DTPA, potential ligand of novel radiopharmaceutical and contrast agent for medical imaging, Bis (amide) of diethyelene triaminepentaacetic acid: DTPA-Bis(INH)

    The structure of isonicotinic acid hydrazide was coupled to diethylenetriaminepentaacetic acid (DTPA) via amide linkage. The Overall yield of three steps synthesis starting from DTPA is above 80%. The new ligand binds with infection site through specific interaction with gene iniA, iniB and iniC under pathological conditions. In particular, complexation of DTPA moiety with 99mTc and Gd+III showed excellent results as metallopharmaceutical for medical imaging. Primary object of the present invention is to propose a novel INH derivative based on DTPA, which form stable complexes with most of lanthanides and transition metals in periodic table. Another object of the present invention is to introduce a chelating group without compromising its biological activity for early diagnosis of infection using nuclear medicine and MR techniques. The DTPA-Bis(INH) was synthesized in high yield using simple synthetic procedure. Radiochemical purity was ascertained chromatographically using different solvent system. Blood kinetics in rabbits and biodistribution in mice was studied. The ability of DTPA-Bis(INH) to target infection site in vivo was assessed in gamma scintigraphic studies of normal rabbit and a rabbit with induced tuberculosis. The DTPA-Bis(INH) was characterized by Mass spectroscopy in ESI positive mode, M+H+ was found to be 632.2.The complex was successfully labeled with 99mTc radionuclide with more than 95% labeling efficiency.It was found stable up to 24h. Blood kinetics showed rapid first pass clearance with biological half life t1/2 (F) = 11 min. Imaging of a normal rabbit and a rabbit with induced tuberculosis was carried out. An appreciable activity was visualized in liver and kidneys. In diseased rabbit similar pattern was observed with the accumulation of activity at the tubercular site at 24 h post injection. Biodistribution revealed major accumulation in liver 6.30±0.58%ID/g at 1 h and 6.25±0.11 at 4h and in kidneys 7.65±0.52%ID/g at 1h and 6.70±0

  17. Langmuir films of an amide extracted from Piperaceae and its interaction with phospholipids

    Antunes, P. A.; Oliveira, O. N.; Aroca, R. F.; Chierice, G. O.; Constantino, C. J. L.

    2005-06-01

    In this work, we investigate Langmuir monolayers from an amide extracted from dried roots of Ottonia propinqua, a native Brazilian plant believed to exhibit anesthetic and hallucinogen activities. In addition to producing monolayers from the amide itself, we probe the molecular-level action of the amide on phospholipids employed as simple membrane models. The surface pressure-molecular area ( π- A) isotherms for the amide were little affected by a number of subphase conditions. Almost no changes were observed upon varying the compression speed, spreading volume onto the surface, ions in the subphase, ionic strength and the solution solvent. However, stronger effects occurred when the subphase temperature and pH were altered, as the isotherms were shifted to larger areas with increasing temperatures and decreasing pHs. These results are discussed in terms of the molecular packing adopted by the amide at the air-water interface. In the mixed films with arachidic acid, the area per molecule varied linearly with the concentration of amide, probably due to phase separation. On the other hand, in the mixed films with dipalmitoyl phosphatidyl choline (DPPC), small amounts of the amide were sufficient to change the π- A isotherms significantly. This points to a strong molecular-level interaction, probably between the phosphate group in the zwitterion of DPPC and the nitrogen from the amidic group.

  18. A Novel Saponin Hydrolase from Neocosmospora vasinfecta var. vasinfecta

    Watanabe, Manabu; Sumida, Naomi; Yanai, Koji; Murakami, Takeshi

    2004-01-01

    We isolated a soybean saponin hydrolase from Neocosmospora vasinfecta var. vasinfecta PF1225, a filamentous fungus that can degrade soybean saponin and generate soyasapogenol B. This enzyme was found to be a monomer with a molecular mass of about 77 kDa and a glycoprotein. Nucleotide sequence analysis of the corresponding gene (sdn1) indicated that this enzyme consisted of 612 amino acids and had a molecular mass of 65,724 Da, in close agreement with that of the apoenzyme after the removal of...

  19. Isolation, purification and characterization of a new organphosphorus hydrolase OPHC2

    WU Ningfeng; DENG Minjie; SHI Xiuyun; LIANG Guoyi; YAO Bin; FAN Yunliu

    2004-01-01

    A bacterium with the capability of degrading organphosphorus, identified as Pseudomonas pseudoalcaligenes, is isolated from OP-treated soil. The organphosphorus hydrolase OPHC2 from this bacterium has been purified and characterized. OPHC2 has optimum activity for the reaction at 65℃ and pH 9.0 with methyl parathion as a substrate, it also shows good thermal and pH stability. Most metal ions and chemicals have no effect on the activity of OPHC2. The analyses of nucleotide sequence encoding OPHC2 and amino acid sequence of OPHC2 show that there are lower homologies with those of organphosphorus hydrolase reported in GenBank.

  20. Structure-guided engineering of molinate hydrolase for the degradation of thiocarbamate pesticides.

    José P Leite

    Full Text Available Molinate is a recalcitrant thiocarbamate used to control grass weeds in rice fields. The recently described molinate hydrolase, from Gulosibacter molinativorax ON4T, plays a key role in the only known molinate degradation pathway ending in the formation of innocuous compounds. Here we report the crystal structure of recombinant molinate hydrolase at 2.27 Å. The structure reveals a homotetramer with a single mononuclear metal-dependent active site per monomer. The active site architecture shows similarities with other amidohydrolases and enables us to propose a general acid-base catalysis mechanism for molinate hydrolysis. Molinate hydrolase is unable to degrade bulkier thiocarbamate pesticides such as thiobencarb which is used mostly in rice crops. Using a structural-based approach, we were able to generate a mutant (Arg187Ala that efficiently degrades thiobencarb. The engineered enzyme is suitable for the development of a broader thiocarbamate bioremediation system.

  1. Genetically reduced soluble epoxide hydrolase activity and risk of stroke and other cardiovascular disease

    Lee, Julie; Dahl, Morten; Grande, Peer; Tybjaerg-Hansen, Anne; Nordestgaard, Børge G

    2010-01-01

    BACKGROUND AND PURPOSE: The development of stroke has been linked to lowered levels of epoxyeicosatrienoic acids in the cerebral microvasculature. These substances are metabolized by the enzyme-soluble epoxide hydrolase encoded by the EPHX2 gene. We tested whether genetically reduced soluble...... epoxide hydrolase activity is associated with risk of ischemic stroke, myocardial infarction, and ischemic heart disease. METHODS: We genotyped participants from the Copenhagen City Heart Study (n=10 352), the Copenhagen General Population Study (n=26 042), the Copenhagen Carotid Stroke Study (n=398 cases......=0.08 to 1.00). Similar results were obtained for myocardial infarction and ischemic heart disease in the 3 studies. CONCLUSIONS: Our results show with significant power that genetically reduced soluble epoxide hydrolase activity is not a major risk factor for ischemic stroke, myocardial infarction...

  2. Bifunctional Brønsted Base Catalyzes Direct Asymmetric Aldol Reaction of α-Keto Amides.

    Echave, Haizea; López, Rosa; Palomo, Claudio

    2016-03-01

    The first enantioselective direct cross-aldol reaction of α-keto amides with aldehydes, mediated by a bifunctional ureidopeptide-based Brønsted base catalyst, is described. The appropriate combination of a tertiary amine base and an aminal, and urea hydrogen-bond donor groups in the catalyst structure promoted the exclusive generation of the α-keto amide enolate which reacted with either non-enolizable or enolizable aldehydes to produce highly enantioenriched polyoxygenated aldol adducts without side-products resulting from dehydration, α-keto amide self-condensation, aldehyde enolization, and isotetronic acid formation. PMID:26835655

  3. Structure Determination and Characterization of the Vitamin B[superscript 6] Degradative Enzyme (E)-2-(Acetamidomethylene)succinate Hydrolase

    McCulloch, Kathryn M.; Mukherjee, Tathagata; Begley, Tadhg P.; Ealick, Steven E. (Cornell); (TAM)

    2010-06-22

    The gene identification and kinetic characterization of (E)-2-(acetamidomethylene)succinate (E-2AMS) hydrolase has recently been described. This enzyme catalyzes the final reaction in the degradation of vitamin B{sub 6} and produces succinic semialdehyde, acetate, ammonia, and carbon dioxide from E-2AMS. The structure of E-2AMS hydrolase was determined to 2.3 {angstrom} using SAD phasing. E-2AMS hydrolase is a member of the {alpha}/{beta} hydrolase superfamily and utilizes a serine/histidine/aspartic acid catalytic triad. Mutation of either the nucleophilic serine or the aspartate resulted in inactive enzyme. Mutation of an additional serine residue in the active site causes the enzyme to be unstable and is likely structurally important. The structure also provides insight into the mechanism of hydrolysis of E-2AMS and identifies several potential catalytically important residues.

  4. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    Hasmukh S. Patel; Panchal, Kumar K.

    2004-01-01

    Novel unsaturated poly (ester-amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY.) to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored by using a differential scanning calorimeter ...

  5. Optimization of amide-based EP3 receptor antagonists.

    Lee, Esther C Y; Futatsugi, Kentaro; Arcari, Joel T; Bahnck, Kevin; Coffey, Steven B; Derksen, David R; Kalgutkar, Amit S; Loria, Paula M; Sharma, Raman

    2016-06-01

    Prostaglandin E receptor subtype 3 (EP3) antagonism may treat a variety of symptoms from inflammation to cardiovascular and metabolic diseases. Previously, most EP3 antagonists were large acidic ligands that mimic the substrate, prostaglandin E2 (PGE2). This manuscript describes the optimization of a neutral small molecule amide series with improved lipophilic efficiency (LipE) also known as lipophilic ligand efficiency (LLE) ((a) Nat. Rev. Drug Disc.2007, 6, 881; (b) Annu. Rep. Med. Chem.2010, 45, 380). PMID:27107947

  6. Synthesis and characterization of alternating poly(amide urethane)s

    Sharma, Bhaskar

    2004-01-01

    This thesis deals with the preparation of alternating poly(amide urethane)s which might be of interest for the manufacture of powder coatings. The synthesis of poly(amide urethane)s was performed in environmentally friendly way without using isocyanates or phosgene. The starting materials for the synthesis were e-caprolactam, e-caprolactone, amino alcohols, diamines and carbonic acid derivatives, i.e. diphenyl carbonate and ethylene carbonate as substitutes for phosgene. A new synthesis was d...

  7. Zirconyl chloride promoted highly efficient solid phase synthesis of amide derivatives

    2007-01-01

    An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was described. In this way, a range of interesting amide derivatives was obtained in good to excellent yields. The catalyst was recycled with fresh reactants and it gave almost similar results without significant loss of activity up to the third run.

  8. Soluble epoxide hydrolase: A potential target for metabolic diseases.

    He, Jinlong; Wang, Chunjiong; Zhu, Yi; Ai, Ding

    2016-05-01

    Epoxyeicosatrienoic acids (EETs), important lipid mediators derived from arachidonic acid, have many beneficial effects in metabolic diseases, including atherosclerosis, hypertension, cardiac hypertrophy, diabetes, non-alcoholic fatty liver disease, and kidney disease. Epoxyeicosatrienoic acids can be further hydrolyzed to less active diols by the enzyme soluble epoxide hydrolase (sEH). Increasing evidence suggests that inhibition of sEH increases levels of EETs, which have anti-inflammatory effects and can prevent the development of hypertension, atherosclerosis, heart failure, fatty liver, and multiple organ fibrosis. Arachidonic acid is the most abundant omega-6 polyunsaturated fatty acid (PUFA) and shares the same set of enzymes with omega-3 PUFAs, such as docosahexaenoic acid and eicosapentaenoic acid. The omega-3 PUFAs and metabolites, such as regioisomeric epoxyeicosatetraenoic acids and epoxydocosapentaenoic acids, have been reported to have strong vasodilatory and anti-inflammatory effects. Therefore, sEH may be a potential therapeutic target for metabolic disorders. In this review, we focus on our and other recent studies of the functions of sEH, including the effects of its eicosanoid products from both omega-3 and omega-6 PUFAs, in various metabolic diseases. We also discuss the possible cellular and molecular mechanisms underlying the regulation of sEH. PMID:26621325

  9. Orientation Preferences of Backbone Secondary Amide Functional Groups in Peptide Nucleic Acid Complexes: Quantum Chemical Calculations Reveal an Intrinsic Preference of Cationic D-Amino Acid-Based Chiral PNA Analogues for the P-form

    Topham, Christopher M.; Smith, Jeremy C.

    2006-01-01

    Geometric descriptions of nonideal interresidue hydrogen bonding and backbone-base water bridging in the minor groove are established in terms of polyamide backbone carbonyl group orientation from analyses of residue junction conformers in experimentally determined peptide nucleic acid (PNA) complexes. Two types of interresidue hydrogen bonding are identified in PNA conformers in heteroduplexes with nucleic acids that adopt A-like basepair stacking. Quantum chemical calculations on the bindin...

  10. Active site and laminarin binding in glycoside hydrolase family 55.

    Bianchetti, Christopher M; Takasuka, Taichi E; Deutsch, Sam; Udell, Hannah S; Yik, Eric J; Bergeman, Lai F; Fox, Brian G

    2015-05-01

    The Carbohydrate Active Enzyme (CAZy) database indicates that glycoside hydrolase family 55 (GH55) contains both endo- and exo-β-1,3-glucanases. The founding structure in the GH55 is PcLam55A from the white rot fungus Phanerochaete chrysosporium (Ishida, T., Fushinobu, S., Kawai, R., Kitaoka, M., Igarashi, K., and Samejima, M. (2009) Crystal structure of glycoside hydrolase family 55 β-1,3-glucanase from the basidiomycete Phanerochaete chrysosporium. J. Biol. Chem. 284, 10100-10109). Here, we present high resolution crystal structures of bacterial SacteLam55A from the highly cellulolytic Streptomyces sp. SirexAA-E with bound substrates and product. These structures, along with mutagenesis and kinetic studies, implicate Glu-502 as the catalytic acid (as proposed earlier for Glu-663 in PcLam55A) and a proton relay network of four residues in activating water as the nucleophile. Further, a set of conserved aromatic residues that define the active site apparently enforce an exo-glucanase reactivity as demonstrated by exhaustive hydrolysis reactions with purified laminarioligosaccharides. Two additional aromatic residues that line the substrate-binding channel show substrate-dependent conformational flexibility that may promote processive reactivity of the bound oligosaccharide in the bacterial enzymes. Gene synthesis carried out on ∼30% of the GH55 family gave 34 active enzymes (19% functional coverage of the nonredundant members of GH55). These active enzymes reacted with only laminarin from a panel of 10 different soluble and insoluble polysaccharides and displayed a broad range of specific activities and optima for pH and temperature. Application of this experimental method provides a new, systematic way to annotate glycoside hydrolase phylogenetic space for functional properties. PMID:25752603

  11. Development of an efficient 18O epoxide labeling method: Investigation of the cytosolic expoxide hydrolase mechanism

    Mechanistic studies of Cytosolic Epoxide Hydrolase (CEH) reveal an anti opening of the epoxide arising from base catalyzed activation of H2O, possibly in concert with acidic activation of the epoxide oxygen. Preliminary data on the hydrolysis of fatty acid oxides shows the CEH is able to discriminate between chemically equivalent epoxide carbons. The research is geared toward methodology development in which CEH could be used as a organic synthetic tool, with substrate and product regio-, stereo-, and enantioselectivity

  12. Efficient Calculation of Enzyme Reaction Free Energy Profiles Using a Hybrid Differential Relaxation Algorithm: Application to Mycobacterial Zinc Hydrolases.

    Romero, Juan Manuel; Martin, Mariano; Ramirez, Claudia Lilián; Dumas, Victoria Gisel; Marti, Marcelo Adrián

    2015-01-01

    Determination of the free energy profile for an enzyme reaction mechanism is of primordial relevance, paving the way for our understanding of the enzyme's catalytic power at the molecular level. Although hybrid, mostly DFT-based, QM/MM methods have been extensively applied to this type of studies, achieving accurate and statistically converged results at a moderate computational cost is still an open challenge. Recently, we have shown that accurate results can be achieved in less computational time, combining Jarzynski's relationship with a hybrid differential relaxation algorithm (HyDRA), which allows partial relaxation of the solvent during the nonequilibrium steering of the reaction. In this work, we have applied this strategy to study two mycobacterial zinc hydrolases. Mycobacterium tuberculosis infections are still a worldwide problem and thus characterization and validation of new drug targets is an intense field of research. Among possible drug targets, recently two essential zinc hydrolases, MshB (Rv1170) and MA-amidase (Rv3717), have been proposed and structurally characterized. Although possible mechanisms have been proposed by analogy to the widely studied human Zn hydrolases, several key issues, particularly those related to Zn coordination sphere and its role in catalysis, remained unanswered. Our results show that mycobacterial Zn hydrolases share a basic two-step mechanism. First, the attacking water becomes deprotonated by the conserved base and establishes the new C-O bond leading to a tetrahedral intermediate. The intermediate requires moderate reorganization to allow for proton transfer to the amide N and C-N bond breaking to occur in the second step. Zn ion plays a key role in stabilizing the tetrahedral intermediate and balancing the negative charge of the substrate during hydroxide ion attack. Finally, comparative analysis of other Zn hydrolases points to a convergent mechanistic evolution. PMID:26415840

  13. Supercritical fluid extraction of uranium and thorium employing dialkyl amides

    Extraction and purification of actinides from different matrices is of utmost importance to the nuclear industry. In recent decades, supercritical fluid extraction (SFE) has emerged as a promising alternative to solvent extraction owing to its inherent potential of minimization of liquid waste generation. N,N-dialkyl aliphatic amides have been proposed to be an alternative to TBP in the reprocessing of spent nuclear fuel due to several attractive features like innocuous nature of degradation products (mainly carboxylic acids/ amines), possibility of complete incineration of the used extractant leading to reduction in volume of secondary waste. Also, physico-chemical properties of this class of extractants can be tuned by the judicious choice of alkyl groups. In the present work, N,N-dialkyl aliphatic amides with varying alkyl groups viz. N,N-dibutyl-2-ethylhexanamide (DBEHA), N,N-dibutyl-3,3-dimethylbutanamide (DBDMBA), N,N-dihexyloctanamide (DHOA), N,N-disecbutylpentamide (DBPA), N,N-dibutyloctanamide (DBOA), have been evaluated for supercritical fluid extraction (SFE) of uranium and thorium from nitric acid medium as well as tissue paper matrix. Amides were obtained from Department of Chemistry, Delhi University and were used as such. This fact could be exploited for separation of thorium and uranium

  14. Characterization and purification of bile salt hydrolase from Lactobacillus sp. strain 100-100

    The authors have characterized and purified the bile salt hydrolase from Lactobacillus sp. strain 100-100. Bile salt hydrolase from cells of the strain was purified with column and high-performance liquid chromatography. The activity was assayed in whole cells and cell-free extracts with either a radiochemical assay involving [14C]taurocholic acid or a nonradioactive assay involving trinitrobenzene sulfonate. The activity was detectable only in stationary-phase cells. Within 20 min after conjugated bile acids were added to stationary-phase cultures of strain 100-100, the activity in whole cells increased to levels three- to fivefold higher than in cells from cultures grown in medium free of bile salts. In cell-free extracts, however, the activity was about equal whether or not the cells have been grown with bile salts present. When supernatant solutions from cultures grown in medium containing taurocholic acid were used to suspend cells grown in medium free of the bile salt, the bile salt hydrolase activity detected in whole cells increased two- to threefold. Two forms of the hydrolase were purified from the cells and designated hydrolases A and B. They eluted from anion-exchange high-performance liquid chromatography in two sets of fractions, A at 0.15 M NaCl and B at 0.18 M NaCl. Their apparent molecular weights in nondenaturing polyacrylamide gel electrophoresis were 115,000 and 105,000, respectively. However, discrepancies existed in the apparent molecular weights and number of peptides detected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the two forms. Whether the enzyme exists in two forms in the cells remains to be determined

  15. A two-step approach to achieve secondary amide transamidation enabled by nickel catalysis

    Baker, Emma L.; Yamano, Michael M.; Zhou, Yujing; Anthony, Sarah M.; Garg, Neil K.

    2016-01-01

    A long-standing challenge in synthetic chemistry is the development of the transamidation reaction. This process, which involves the conversion of one amide to another, is typically plagued by unfavourable kinetic and thermodynamic factors. Although some advances have been made with regard to the transamidation of primary amide substrates, secondary amide transamidation has remained elusive. Here we present a simple two-step approach that allows for the elusive overall transformation to take place using non-precious metal catalysis. The methodology proceeds under exceptionally mild reaction conditions and is tolerant of amino-acid-derived nucleophiles. In addition to overcoming the classic problem of secondary amide transamidation, our studies expand the growing repertoire of new transformations mediated by base metal catalysis. PMID:27199089

  16. Orientation Preferences of Backbone Secondary Amide Functional Groups in Peptide Nucleic Acid Complexes: Quantum Chemical Calculations Reveal an Intrinsic Preference of Cationic D-Amino Acid-Based Chiral PNA Analogues for the P-form

    Smith, Jeremy C [ORNL; Topham, Christopher [University of Heidelberg

    2007-01-01

    Geometric descriptions of nonideal interresidue hydrogen bonding and backbone-base water bridging in the minor groove are established in terms of polyamide backbone carbonyl group orientation from analyses of residue junction conformers in experimentally determined peptide nucleic acid (PNA) complexes. Two types of interresidue hydrogen bonding are identified in PNA conformers in heteroduplexes with nucleic acids that adopt A-like base pair stacking. Quantum chemical calculations on the binding of a water molecule to an O2 base atom in glycine-based PNA thymine dimers indicate that junctions modeled with P-form backbone conformations are lower in energy than a dimer comprising the predominant conformation observed in A-like helices. It is further shown in model systems that PNA analogs based on D-lysine are better able to preorganize in a conformation exclusive to P-form helices than is glycine-based PNA. An intrinsic preference for this conformation is also exhibited by positively charged chiral PNA dimers carrying 3-amino-D-alanine or 4-aza-D-leucine residue units that provide for additional rigidity by side-chain hydrogen bonding to the backbone carbonyl oxygen. Structural modifications stabilizing P-form helices may obviate the need for large heterocycles to target DNA pyrimidine bases via PNADNA-PNA triplex formation. Quantum chemical modeling methods are used to propose candidate PNA Hoogsteen strand designs.

  17. Orientation preferences of backbone secondary amide functional groups in peptide nucleic acid complexes: quantum chemical calculations reveal an intrinsic preference of cationic D-amino acid-based chiral PNA analogues for the P-form.

    Topham, Christopher M; Smith, Jeremy C

    2007-02-01

    Geometric descriptions of nonideal interresidue hydrogen bonding and backbone-base water bridging in the minor groove are established in terms of polyamide backbone carbonyl group orientation from analyses of residue junction conformers in experimentally determined peptide nucleic acid (PNA) complexes. Two types of interresidue hydrogen bonding are identified in PNA conformers in heteroduplexes with nucleic acids that adopt A-like basepair stacking. Quantum chemical calculations on the binding of a water molecule to an O2 base atom in glycine-based PNA thymine dimers indicate that junctions modeled with P-form backbone conformations are lower in energy than a dimer comprising the predominant conformation observed in A-like helices. It is further shown in model systems that PNA analogs based on D-lysine are better able to preorganize in a conformation exclusive to P-form helices than is glycine-based PNA. An intrinsic preference for this conformation is also exhibited by positively charged chiral PNA dimers carrying 3-amino-D-alanine or 4-aza-D-leucine residue units that provide for additional rigidity by side-chain hydrogen bonding to the backbone carbonyl oxygen. Structural modifications stabilizing P-form helices may obviate the need for large heterocycles to target DNA pyrimidine bases via PNA.DNA-PNA triplex formation. Quantum chemical modeling methods are used to propose candidate PNA Hoogsteen strand designs. PMID:17071666

  18. Mechanistic insight into benzenethiol catalyzed amide bond formations from thioesters and primary amines

    Stuhr-Hansen, Nicolai; Bork, Nicolai; Strømgaard, Kristian

    2014-01-01

    The influence of arylthiols on cysteine-free ligation, i.e. the reaction between an alkyl thioester and a primary amine forming an amide bond, was studied in a polar aprotic solvent. We reacted the ethylthioester of hippuric acid with cyclohexylamine in the absence or presence of various quantities...... state in the aromatic thioester amidation reaction. Under similar conditions, cysteine-free ligation was achieved by coupling a fully side-chain protected 15 amino acid phosphopeptide thioester to the free N-terminal of a side-chain protected 9 amino acid peptide producing the corresponding 24 amino...... of thiophenol (PhSH) in a slurry of disodium hydrogen phosphate in dry DMF. Quantitative conversions into the resulting amide were observed within a few hours in the presence of equimolar amounts of thiophenol. Ab initio calculations showed that the reaction mechanism in DMF is similar to the well...

  19. Characteristics, protein engineering and applications of microbial thermostable pullulanases and pullulan hydrolases.

    Nisha, M; Satyanarayana, T

    2016-07-01

    Pullulan hydrolyzing enzymes are endoacting, classified based on the substrate specificity and hydrolysis products as pullulanases (type I and II) and pullulan hydrolases (type I, II and III). Pullulanases and pullulan hydrolase type I are produced by bacteria and archaea. Among bacteria, many mesophilic, thermophilic and hyperthermophilic bacteria produce pullulanases and neopullulanases. While pullulan hydrolase type II and type III are produced by fungi and archaea, respectively. These are multi-domain proteins with three conserved catalytic acidic residues of the glycosyl hydrolases. The recent advances in molecular biology and protein engineering via mutagenesis and truncation led to improvement in thermostability, catalytic activity and substrate specificity. Pullulanases are debranching enzymes, which are widely employed in starch saccharification that minimizes the use of glucoamylase (approx. 50 %) and reduces the total reaction time of the industrial starch conversion process. The thermostable amylopullulanases are useful in one-step starch liquefaction and saccharification, which replaces amylolytic enzymes like α-amylase and glucoamylase, thus resulting in the reduction in the cost of sugar production. The enzymes also find application in making resistant starches and as an antistale in bread making. Panose and isopanose containing syrups are useful as prebiotics, while panose has also been reported to display anticarcinogenic activity. This review focuses on the distinguishing features of these enzymes based on the analysis of amino acid sequences and domain structure, besides highlighting recent advances in the molecular biology and protein engineering for enhancing their thermostability, catalytic activity and substrate specificity. This review also briefly summarizes the potential applications of pullulanases and pullulan hydrolases. PMID:27142298

  20. Novel endogenous N-acyl amides activate TRPV1-4 receptors, BV-2 microglia, and are regulated in brain in an acute model of inflammation

    Siham eRaboune

    2014-08-01

    Full Text Available A family of endogenous lipids, structurally analogous to the endogenous cannabinoid, N-arachidonoyl ethanolamine (Anandamide, and called N-acyl amides have emerged as a family of biologically active compounds at TRP receptors. N-acyl amides are constructed from an acyl group and an amine via an amide bond. This same structure can be modified by changing either the fatty acid or the amide to form potentially hundreds of lipids. More than 70 N-acyl amides have been identified in nature. We have ongoing studies aimed at isolating and characterizing additional members of the family of N-acyl amides in both central and peripheral tissues in mammalian systems. Here, using a unique in-house library of over 70 N-acyl amides we tested the following three hypotheses: 1 Additional N-acyl amides will have activity at TRPV1-4, 2 Acute peripheral injury will drive changes in CNS levels of N-acyl amides, and 3 N-acyl amides will regulate calcium in CNS-derived microglia. Through these studies, we have identified 20 novel N-acyl amides that collectively activate (stimulating or inhibiting TRPV1-4. Using lipid extraction and HPLC coupled to tandem mass spectrometry we showed that levels of at least 10 of these N-acyl amides that activate TRPVs are regulated in brain after intraplantar carrageenan injection. We then screened the BV2 microglial cell line for activity with this N-acyl amide library and found overlap with TRPV receptor activity as well as additional activators of calcium mobilization from these lipids. Together these data provide new insight into the family of N-acyl amides and their roles as signaling molecules at ion channels, in microglia, and in the brain in the context of inflammation.

  1. Structure of the minimized α/β-hydrolase fold protein from Thermus thermophilus HB8

    The crystal structure of the minimized α/β-hydrolase fold protein encoded by the gene TTHA1544 from T. thermophilus HB8 has been determined at 2.0 Å resolution. The gene encoding TTHA1544 is a singleton found in the Thermus thermophilus HB8 genome and encodes a 131-amino-acid protein. The crystal structure of TTHA1544 has been determined at 2.0 Å resolution by the single-wavelength anomalous dispersion method in order to elucidate its function. There are two molecules in the asymmetric unit. Each molecule consists of four α-helices and six β-strands, with the β-strands composing a central β-sheet. A structural homology search revealed that the overall structure of TTHA1544 resembles the α/β-hydrolase fold, although TTHA1544 lacks the catalytic residues of a hydrolase. These results suggest that TTHA1544 represents the minimized α/β-hydrolase fold and that an additional component would be required for its activity

  2. The grafting and release behavior of doxorubincin from Fe{sub 3}O{sub 4}-SiO{sub 2} core-shell structure nanoparticles via an acid cleaving amide bond: the potential for magnetic targeting drug delivery

    Chen, F H; Gao, Q; Ni, J Z [State Key Laboratory of Rare Earth Resources and Application, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)], E-mail: jzni@ciac.jl.cn

    2008-04-23

    Fe{sub 3}O{sub 4}-SiO{sub 2} core-shell structure nanoparticles were first prepared and characterized by TEM, FTIR, XPS and XRD. Subsequently the widely used anticancer agent doxorubincin (DOX) was successfully grafted to the surface of the core-shell nanoparticles via an amide bond with the aid of a spacer arm we synthesized. The spacer arm met two needs: one end can couple to the core-shell nanoparticles' surface while the other end was the active -COOH group, which can react with the -NH{sub 2} group of DOX molecules. The synthesized spacer arm and the conjugation of the drug with nanoparticles through amidation were confirmed by FTIR. The DOX-loading efficiency determined by UV-vis spectrometer was 86.5%. Drug release experiments displayed a pH-dependent behavior that DOX was cleaved from the nanoparticles easily under low pH conditions in the presence of protease and that most of the conjugated doxorubincin were released within the first 12 h. The prepared DOX-grafted Fe{sub 3}O{sub 4}-SiO{sub 2} core-shell structure nanoparticles showed a superparamagnetic property with a saturation magnetization value of 49.3 emu g{sup -1}, indicating a great potential application in the treatment of cancer using magnetic targeting drug-delivery technology.

  3. Novel carbon-11 labeled 4-dimethylamino-but-2-enoic acid [4-(phenylamino)-quinazoline-6-yl]-amides: potential PET bioprobes for molecular imaging of EGFR-positive tumors

    We have previously reported of labeled reversible and irreversible EGFR inhibitors, such as 4-(3,4-dichloro-6-fluoroanilino)-6,7-dimethoxyquinazoline (ML01) and 6-acrylamido-4-(3,4-dichloro-6-fluoroanilino)quinazoline (ML03), to be suboptimal as imaging agents. On the basis of these studies, a new generation of novel, more chemically stable irreversible inhibitors was labeled with carbon-11 as potential positron emission tomography (PET) biomarkers for molecular imaging of epidermal growth factor receptor (EGFR)-positive tumors. In these new labeled, irreversible inhibitors the acryl-amide group at the 6-position of the quinazoline ring was replaced with a 4-dimethylamino-but-2-enoic amide. The nonlabeled compounds were evaluated in vitro to determine their EGFR autophosphorylation IC50 values. The IC50 values indicated that these new irreversible compounds possess similar potencies towards the EGFR, as the parent compound, ML03. These compounds were labeled with carbon-11 at the dimethylamine moiety, using the well known labeling reagent C-11 MeI. The labeling procedure was automated using a commercial module. The final products were obtained with 10% decay corrected radiochemical yield, 99% radiochemical purity, 96% chemical purity, and a high specific activity of 2.7 Ci/μmol EOB. The high potency of these new labeled bioprobes towards the EGFR establishes their potential to serve as PET agents for molecular imaging of EGFR-positive tumors

  4. First synthesis and anticancer activity of novel naphthoquinone amides.

    Pradidphol, Narathip; Kongkathip, Ngampong; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Boonsong

    2012-03-01

    Sixteen novel naphthoquinone aromatic amides were synthesized by a new route starting from 1-hydroxy-2-naphthoic acid in nine or ten steps with good to excellent yield. Amide formation reaction was carried out by using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as an efficient condensing agent leading to carboxamides in high yield. The key step for converting naphthol to 3-hydroxynaphthoquinone was the Fremy's salt oxidation followed by hydroxylation with tert-butyl hydroperoxide and triton B. Anticancer activity of these new naphthoquinone amides were evaluated and benzamide 22 showed potent inhibition against NCI-H187 cell lines while naphthamides 23 and 43 were the most potent inhibition against KB cells. The decatenation assay revealed that compounds 24 and 43 at 20 μM can inhibit hTopoIIα activity while three other compounds, namely compounds 22, 23, and 45, exhibited hTopoIIα inhibitory activity at final concentration of 50 μM. Docking experiment revealed the same trend as the cytotoxicity and decatenation assay. Therefore, naphthamides 24 and 43 can be promising target molecules for anticancer drug development. PMID:22280818

  5. Amide functionalized MWNT/SPEEK composite membrane for better electrochemical performance

    Gahlot, Swati; Sharma, Prem P.; Kulshrestha, Vaibhav

    2016-05-01

    Nanocomposite membranes based on multiwalled carbon nanotube /SPEEK (sulfonated poly ether ether ketone) have been synthesized via simple solution casting. Prior to use CNT have been purified and grafted with carboxylic acid groups onto its walls by means of sulfuric and nitric acid. Afterwards, amidation of carboxylated CNTs (c-CNT) has been done. Amidated CNT (a-CNT) is then incorporated in SPEEK polymer matrix to synthesize nanocomposite membranes. Physicochemical, structural, thermal and mechanical characterizations are done through the respective techniques. Electric and ionic conductivities have also been evaluated. Composites membranes show the enhanced electrochemical performance with higher electric conductivity.

  6. Alpha-amidated peptides derived from pro-opiomelanocortin in normal human pituitary

    Fenger, M; Johnsen, A H

    1988-01-01

    Normal human pituitaries were extracted in boiling water and acetic acid, and the alpha-amidated peptide products of pro-opiomelanocortin (POMC), alpha-melanocyte-stimulating hormone (alpha MSH), gamma-melanocyte-stimulating hormone (gamma 1MSH), and amidated hinge peptide (HP-N), as well as their...... glycine-extended precursors, were characterized by sequence-specific radioimmunoassays, gel-chromatography, h.p.l.c. and amino acid sequencing. alpha MSH and gamma 1MSH constituted 0.27-1.32% and 0.10-5.10%, respectively, of the POMC-derived products [calculated as the sum of adrenocorticotropic hormone...

  7. Structure-property relationship of aliphatic segmented poly(ester amide)s

    Garg, Priya

    2010-01-01

    This thesis focuses on the synthesis, characterization and applications of aliphatic segmented poly(ester amide)s (PEA)s for use as potential biomaterials. Three different series of PEAs with different microstructures containing isolated, two and three adjacent amide groups within a polybutylene adipate (PBA) chain have been synthesized. Analytical techniques such as NMR (liquid and solid-state), SEC, DSC, FT-IR, WAXD and microscopy (AFM, SEM, optical) have been extensively used to characteri...

  8. Orthogonal dipolar interactions between amide carbonyl groups

    Fischer, Felix R.; Wood, Peter A.; Allen, Frank H; Diederich, François

    2008-01-01

    Orthogonal dipolar interactions between amide C=O bond dipoles are commonly found in crystal structures of small molecules, proteins, and protein–ligand complexes. We herein present the experimental quantification of such interactions by employing a model system based on a molecular torsion balance. Application of a thermodynamic double-mutant cycle allows for the determination of the incremental energetic contributions attributed to the dipolar contact between 2 amide C=O groups. The stabili...

  9. GENETIC VARIATION IN SOLUBLE EPOXIDE HYDROLASE (EPHX2) IS ASSOCIATED WITH FOREARM VASODILATOR RESPONSES IN HUMANS

    Lee, Craig R.; Pretorius, Mias; Schuck, Robert N.; Burch, Lauranell H.; Bartlett, Jackie; Williams, Scott M.; ZELDIN, DARRYL C.; Brown, Nancy J.

    2010-01-01

    Cytochrome P450-derived epoxyeicosatrienoic acids are potent vasodilators in preclinical models and are hydrolyzed by soluble epoxide hydrolase (EPHX2). Associations between the EPHX2 Lys55Arg and Arg287Gln polymorphisms and cardiovascular disease risk have been reported; however, their impact on vascular function in humans has not been investigated. In 265 volunteers (198 white, 67 black American), forearm blood flow was measured by strain-gauge venous occlusion plethysmography at baseline a...

  10. Soluble Epoxide Hydrolase Inhibition: Targeting Multiple Mechanisms of Ischemic Brain Injury with a Single Agent

    Iliff, Jeffrey J.; Alkayed, Nabil J.

    2009-01-01

    Soluble epoxide hydrolase (sEH) is a key enzyme in the metabolic conversion and degradation of P450 eicosanoids called epoxyeicosatrienoic acids (EETs). Genetic variations in the sEH gene, designated EPHX2, are associated with ischemic stroke risk. In experimental studies, sEH inhibition and gene deletion reduce infarct size after focal cerebral ischemia in mice. Although the precise mechanism of protection afforded by sEH inhibition remains under investigation, EETs exhibit a wide array of p...

  11. Soluble epoxide hydrolase inhibition and gene deletion are protective against myocardial ischemia-reperfusion injury in vivo

    Motoki, Atsuko; Merkel, Matthias J.; Packwood, William H.; Cao, Zhiping; Liu, Lijuan; Iliff, Jeffrey; Alkayed, Nabil J.; Van Winkle, Donna M.

    2008-01-01

    Soluble epoxide hydrolase (sEH) metabolizes epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids. EETs are formed from arachidonic acid during myocardial ischemia and play a protective role against ischemic cell death. Deletion of sEH has been shown to be protective against myocardial ischemia in the isolated heart preparation. We tested the hypothesis that sEH inactivation by targeted gene deletion or pharmacological inhibition reduces infarct size (I) after regional myocardial ...

  12. Molecular Identification of β-Citrylglutamate Hydrolase as Glutamate Carboxypeptidase 3*

    Collard, François; Vertommen, Didier; Constantinescu, Stefan; Buts, Lieven; Van Schaftingen, Emile

    2011-01-01

    β-Citrylglutamate (BCG), a compound present in adult testis and in the CNS during the pre- and perinatal periods is synthesized by an intracellular enzyme encoded by the RIMKLB gene and hydrolyzed by an as yet unidentified ectoenzyme. To identify β-citrylglutamate hydrolase, this enzyme was partially purified from mouse testis and characterized. Interestingly, in the presence of Ca2+, the purified enzyme specifically hydrolyzed β-citrylglutamate and did not act on N-acetyl-aspartylglutamate (NAAG). However, both compounds were hydrolyzed in the presence of Mn2+. This behavior and the fact that the enzyme was glycosylated and membrane-bound suggested that β-citrylglutamate hydrolase belonged to the same family of protein as glutamate carboxypeptidase 2 (GCP2), the enzyme that catalyzes the hydrolysis of N-acetyl-aspartylglutamate. The mouse tissue distribution of β-citrylglutamate hydrolase was strikingly similar to that of the glutamate carboxypeptidase 3 (GCP3) mRNA, but not that of the GCP2 mRNA. Furthermore, similarly to β-citrylglutamate hydrolase purified from testis, recombinant GCP3 specifically hydrolyzed β-citrylglutamate in the presence of Ca2+, and acted on both N-acetyl-aspartylglutamate and β-citrylglutamate in the presence of Mn2+, whereas recombinant GCP2 only hydrolyzed N-acetyl-aspartylglutamate and this, in a metal-independent manner. A comparison of the structures of the catalytic sites of GCP2 and GCP3, as well as mutagenesis experiments revealed that a single amino acid substitution (Asn-519 in GCP2, Ser-509 in GCP3) is largely responsible for GCP3 being able to hydrolyze β-citrylglutamate. Based on the crystal structure of GCP3 and kinetic analysis, we propose that GCP3 forms a labile catalytic Zn-Ca cluster that is critical for its β-citrylglutamate hydrolase activity. PMID:21908619

  13. Molecular identification of β-citrylglutamate hydrolase as glutamate carboxypeptidase 3.

    Collard, François; Vertommen, Didier; Constantinescu, Stefan; Buts, Lieven; Van Schaftingen, Emile

    2011-11-01

    β-Citrylglutamate (BCG), a compound present in adult testis and in the CNS during the pre- and perinatal periods is synthesized by an intracellular enzyme encoded by the RIMKLB gene and hydrolyzed by an as yet unidentified ectoenzyme. To identify β-citrylglutamate hydrolase, this enzyme was partially purified from mouse testis and characterized. Interestingly, in the presence of Ca(2+), the purified enzyme specifically hydrolyzed β-citrylglutamate and did not act on N-acetyl-aspartylglutamate (NAAG). However, both compounds were hydrolyzed in the presence of Mn(2+). This behavior and the fact that the enzyme was glycosylated and membrane-bound suggested that β-citrylglutamate hydrolase belonged to the same family of protein as glutamate carboxypeptidase 2 (GCP2), the enzyme that catalyzes the hydrolysis of N-acetyl-aspartylglutamate. The mouse tissue distribution of β-citrylglutamate hydrolase was strikingly similar to that of the glutamate carboxypeptidase 3 (GCP3) mRNA, but not that of the GCP2 mRNA. Furthermore, similarly to β-citrylglutamate hydrolase purified from testis, recombinant GCP3 specifically hydrolyzed β-citrylglutamate in the presence of Ca(2+), and acted on both N-acetyl-aspartylglutamate and β-citrylglutamate in the presence of Mn(2+), whereas recombinant GCP2 only hydrolyzed N-acetyl-aspartylglutamate and this, in a metal-independent manner. A comparison of the structures of the catalytic sites of GCP2 and GCP3, as well as mutagenesis experiments revealed that a single amino acid substitution (Asn-519 in GCP2, Ser-509 in GCP3) is largely responsible for GCP3 being able to hydrolyze β-citrylglutamate. Based on the crystal structure of GCP3 and kinetic analysis, we propose that GCP3 forms a labile catalytic Zn-Ca cluster that is critical for its β-citrylglutamate hydrolase activity. PMID:21908619

  14. High levels of γ-glutamyl hydrolase (GGH) are associated with poor prognosis and unfavorable clinical outcomes in invasive breast cancer

    Previously, we performed analysis of gene expression in 46 axillary lymph node negative tumors and identified molecular gene signatures that resulted in different clinical outcomes. The aim of this study was to determine the correlation of γ-glutamyl hydrolase (GGH), fatty acid amide hydrolase (FAAH), Pirin (PIR) and TAF5-like RNA polymerase II, p300/CBP-associated factor (PCAF)-associated factor, 65 kDa (TAF5L), selected from identified gene signatures, with clinical outcomes as well as classical clinicopathological characteristics in primary invasive breast cancer patients. The protein levels of GGH, FAAH, PIR and TAF5L were assessed by immunohistochemistry (IHC) on a panel of 80 primary invasive breast tumors. Quantitative real-time PCR (qRT-PCR) and western blot analysis were performed to verify the expression levels of the candidate biomarkers. Patient disease-specific survival (DSS) and recurrence-free survival (RFS) were evaluated using the Kaplan-Meier method. The prognostic biomarkers were identified by univariate analysis with a log-rank test and by multivariate analysis with Cox proportional hazards regression models. The GGH and FAAH protein levels were significantly up-regulated in invasive breast cancer tumors compared with adjacent non-cancerous tissues. Furthermore, the protein levels of GGH and FAAH were significantly correlated in tumor tissues. Tumoral GGH protein expression was significantly correlated with shorter DSS and RFS. Furthermore, the protein expression of GGH was positively correlated with undifferentiated tumors (BRE grade III) and ER/PR expressing tumors. Multivariate regression analysis showed that only GGH protein expression independently predicts DSS. No such correlations were found for FAAH, PIR and TAF5L protein expression. However, elevated protein levels of FAAH were positively associated with high number of lymph node involvement and upregulated levels of PIR were positively related with lymph node metastasis. The TAF5L was

  15. Synthesis of amide derivatives of 6{alpha},7{beta}-di-hydroxyvouacapan-17{beta}-oic acid isolated from the Pterodon polygalaeflorus Benth fruits (leguminosae); Sintese de amidas derivadas do acido 6{alpha},7{beta}-di-hidroxivouacapan-17{beta}-oico isolado dos frutos de Pterodon polygalaeflorus Benth (leguminosae)

    Teixeira, A.L.; Belinelo, V.J.; Stefani, G.M.; Pilo-Veloso, D. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica]. E-mail: dorila@dedalus.lcc.ufmg.br; Reis, G.T. [Universidade de Itauna, MG (Brazil). Dept. de Ciencias; Ferreira-Alves, D.L. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Farmacologia

    2001-04-01

    Hydro-alcoholic infusions from fruits of Pterodon polygalaeflorus Benth, commonly known as 'Sucupira branca', are used in Brazilian folk medicine for rheumatic problems and throat infections. Since it has been verified that furanediterpene 6?,7?-di-hydroxyvouacapan-17?-oic acid (ADV), isolated from the hexane extract of these fruits presents anti-inflammatory, analgesic, and plant growth regulatory activity, a variety of ADV derivatives has been synthesized with the aim of obtaining more information about the structure-activity relationships of this series of compounds. In this work four new amide (4-7) derivatives of ADV have been synthesized. Their structures were established by spectroscopic data, including 2D-NMR methods. (author)

  16. Structural analysis of Clostridium acetobutylicum ATCC 824 glycoside hydrolase from CAZy family GH105

    Germane, Katherine L., E-mail: katherine.germane.civ@mail.mil [Oak Ridge Associated Universities, 4692 Millennium Drive, Suite 101, Belcamp, MD 21017 (United States); Servinsky, Matthew D. [US Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (United States); Gerlach, Elliot S. [Federal Staffing Resources, 2200 Somerville Road, Annapolis, MD 21401 (United States); Sund, Christian J. [US Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (United States); Hurley, Margaret M., E-mail: katherine.germane.civ@mail.mil [US Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, MD 21005 (United States); Oak Ridge Associated Universities, 4692 Millennium Drive, Suite 101, Belcamp, MD 21017 (United States)

    2015-07-29

    The crystal structure of the protein product of the C. acetobutylicum ATCC 824 gene CA-C0359 is structurally similar to YteR, an unsaturated rhamnogalacturonyl hydrolase from B. subtilis strain 168. Substrate modeling and electrostatic studies of the active site of the structure of CA-C0359 suggests that the protein can now be considered to be part of CAZy glycoside hydrolase family 105. Clostridium acetobutylicum ATCC 824 gene CA-C0359 encodes a putative unsaturated rhamnogalacturonyl hydrolase (URH) with distant amino-acid sequence homology to YteR of Bacillus subtilis strain 168. YteR, like other URHs, has core structural homology to unsaturated glucuronyl hydrolases, but hydrolyzes the unsaturated disaccharide derivative of rhamnogalacturonan I. The crystal structure of the recombinant CA-C0359 protein was solved to 1.6 Å resolution by molecular replacement using the phase information of the previously reported structure of YteR (PDB entry (http://scripts.iucr.org/cgi-bin/cr.cgi?rm)) from Bacillus subtilis strain 168. The YteR-like protein is a six-α-hairpin barrel with two β-sheet strands and a small helix overlaying the end of the hairpins next to the active site. The protein has low primary protein sequence identity to YteR but is structurally similar. The two tertiary structures align with a root-mean-square deviation of 1.4 Å and contain a highly conserved active pocket. There is a conserved aspartic acid residue in both structures, which has been shown to be important for hydration of the C=C bond during the release of unsaturated galacturonic acid by YteR. A surface electrostatic potential comparison of CA-C0359 and proteins from CAZy families GH88 and GH105 reveals the make-up of the active site to be a combination of the unsaturated rhamnogalacturonyl hydrolase and the unsaturated glucuronyl hydrolase from Bacillus subtilis strain 168. Structural and electrostatic comparisons suggests that the protein may have a slightly different substrate

  17. X-Ray Diffraction Structure of a plant Glycosyl Hydrolase family 32 protein: Fructan 1-Exohydrolase IIa of Cichorium intybus

    Verhaest, Maureen; Van den Ende, Wim; Le Roy, Katrien; De Ranter, Camiel; Van Laere, André; Rabijns, Anja

    2005-01-01

    Fructan 1-exohydrolase, an enzyme involved in fructan degradation, belongs to the glycosyl hydrolase family 32. The structure of isoenzyme 1-FEH IIa from Cichorium intybus is described at a resolution of 2.35 Å. The structure consists of an N-terminal fivefold β-propeller domain connected to two C-terminal β-sheets. The putative active site is located entirely in the β-propeller domain and is formed by amino acids which are highly conserved within glycosyl hydrolase family 32. The fructan-bin...

  18. Crystal structure of bile salt hydrolase from Lactobacillus salivarius.

    Xu, Fuzhou; Guo, Fangfang; Hu, Xiao Jian; Lin, Jun

    2016-05-01

    Bile salt hydrolase (BSH) is a gut-bacterial enzyme that negatively influences host fat digestion and energy harvesting. The BSH enzyme activity functions as a gateway reaction in the small intestine by the deconjugation of glycine-conjugated or taurine-conjugated bile acids. Extensive gut-microbiota studies have suggested that BSH is a key mechanistic microbiome target for the development of novel non-antibiotic food additives to improve animal feed production and for the design of new measures to control obesity in humans. However, research on BSH is still in its infancy, particularly in terms of the structural basis of BSH function, which has hampered the development of BSH-based strategies for improving human and animal health. As an initial step towards the structure-function analysis of BSH, C-terminally His-tagged BSH from Lactobacillus salivarius NRRL B-30514 was crystallized in this study. The 1.90 Å resolution crystal structure of L. salivarius BSH was determined by molecular replacement using the structure of Clostridium perfringens BSH as a starting model. It revealed this BSH to be a member of the N-terminal nucleophile hydrolase superfamily. Crystals of apo BSH belonged to space group P21212, with unit-cell parameters a = 90.79, b = 87.35, c = 86.76 Å (PDB entry 5hke). Two BSH molecules packed perfectly as a dimer in one asymmetric unit. Comparative structural analysis of L. salivarius BSH also identified potential residues that contribute to catalysis and substrate specificity. PMID:27139829

  19. Characterization of intracellular pteroylpolyglutamate hydrolase (PPH) from human intestinal mucosa

    Wang, T.T.Y.; Chandler, C.J.; Halsted, C.H.

    1986-03-01

    There are two forms of pteroylpolyglutamate hydrolase (PPH) in the human intestinal mucosa, one in the brush border membrane and the other intracellular; brush border PPH is an exopeptidase with optimal activity at pH 6.5 and a requirement for zinc. The presence study characterized human intracellular PPH and compared its properties to those of brush border PPH. Intracellular PPH was purified 30-fold. The enzyme had a MW of 75,000 by gel filtration, was optimally active at pH 4.5, and had an isoelectric point at pH 8.0. In contrast to brush border PPH, intracellular PPH was unstable at increasing temperatures, was unaffected by dialysis against chelating agents and showed no requirement for Zn/sup 2 +/. Using PteGlu/sub 2/(/sup 14/C)Glu as substrate, they demonstrated a K/sub m/ of 1.2 ..mu..M and increasing affinity for folates with longer glutamate chains. Intracellular PPH required the complete folic acid (PteGlu) moiety and a ..gamma..-glutamyl linkage for activity. Using ion exchange chromatography and an HPLC method to determine the hydrolytic products of the reaction, they found intracellular PPH could cleave both internal and terminal ..gamma..-glutamyl linkages, with PteGlu as an end product. After subcellular fractionation of the mucosa, PPH was found in the lysosomes. In summary, the distinct characteristics of brush border and intracellular PPH suggest that the two hydrolases serve different roles in folate metabolism.

  20. Convergent synthesis of digitally-encoded poly(alkoxyamine amide)s.

    Roy, Raj Kumar; Laure, Chloé; Fischer-Krauser, Diane; Charles, Laurence; Lutz, Jean-François

    2015-11-01

    Binary-encoded poly(alkoxyamine amide)s were prepared by oligomer ligation. These polymers contain digital sequences based on two monomers defined as 0 and 1 bits. A library of oligomers containing all possible dyads 00, 01, 10 and 11 was prepared and used to construct long coded sequences. PMID:26359908

  1. Aspergillus niger DLFCC-90 Rhamnoside Hydrolase, a New Type of Flavonoid Glycoside Hydrolase

    Liu, Tingqiang; Yu, Hongshan; Zhang, Chunzhi; Lu, Mingchun; Piao, Yongzhe; Ohba, Masashi; Tang, Minqian; Yuan, Xiaodong; Wei, Shenghua; Wang, Kan; Ma, Anzhou; Feng, Xue; Qin, Siqing; Mukai, Chisato; Tsuji, Akira

    2012-01-01

    A novel rutin-α-l-rhamnosidase hydrolyzing α-l-rhamnoside of rutin, naringin, and hesperidin was purified and characterized from Aspergillus niger DLFCC-90, and the gene encoding this enzyme, which is highly homologous to the α-amylase gene, was cloned and expressed in Pichia pastoris GS115. The novel enzyme was classified in glycoside-hydrolase (GH) family 13.

  2. Hydrolase activity in Jerusalem artichoke and chicory

    Klaushofer, H.; Abraham, B.; Leichtfried, G.

    1988-03-01

    Post-harvest storage of chicory and Jerusalem artichoke and overwintering of Jerusalem artichoke in the soil cause a more or less pronounced shortening of the fructan chain, depending on the variety. The proportion of fructose in the total fructan thus shifts towards glucose. This reduction on the fructose/glucose ratio is undesirable if the intention is to obtain a sweetener of high fructose content. In this work an attempt was made, via the quantity of fructose formed after a 4(3)-hour reaction of a tuber (root) extract with inulin, to assign a characteristic value to the depolymerization tendency of the material in question. However, since the plant extract not only contains enzymes (hydrolase A and B) that shorten the fructan chains but the activity of fructosyltransferase (SST, FFT) and enzymes of microbial origin (inulinase II, invertase) must also be considered, the concept of 'hydrolase activity' used by the authors is essentially an expression of 'total activity'. The activity unit (EU) is defined as the ability to split of 1 ..mu..mol of fructose from (chicory) inulin per minute under experimental conditions. Values of 0.25 to 0.77 EU/g dry solids were found in Jerusalem artichoke. Considerable differences may occur between varieties from the same cultivated area and the same harvest period. With one and the same variety, the activity appears to be subject to marked yearly fluctuations, so that at present, because of hydrolase activity, nothing certain can be said about the depolymerization tendency of a variety.

  3. A Two-Dimensional Zinc Coordination Polymer Based on a Pyridyl-Carboxylate Linking Ligand Containing an Intervening Amide Group: [ZnCl(L)]∞ (HL = 6-(nicotinamido)-2-naphthoic acid)

    According to the very recent IUPAC recommendations for the terminology, CPs are coordination compounds with repeating coordination entities extending in 1, 2, or 3 dimensions, and MOFs are coordination networks with organic ligands containing potential voids. IUPAC also recommended the use of the term 'coordination networks' to indicate coordination compounds extending, through repeating coordination entities, in 1 dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or coordination compounds extending through repeating coordination entities in 2 or 3 dimensions. For the successful preparation of such polymeric species, the choice or design of proper linking ligands is essential, and those possessing either pyridyl or carboxylate terminals are typically employed. In particular, we became interested in the pyridyl.carboxylate-type ligands containing an amide (-C(O)-NH-) fragment, which might be utilized further for the so-called post-synthetic modification of CPs and MOFs. In this context, our group recently prepared two ligands of this type (HL and HL' in Chart 1), both of which contain a 3-pyridyl and a carboxylate terminals

  4. Production of R-(-)-Ketoprofen from an Amide Compound by Comamonas acidovorans KPO-2771-4

    Yamamoto, K; Otsubo, K; Matsuo, A.; T Hayashi; Fujimatsu, I; Komatsu, K.

    1996-01-01

    R-(-)-2-(3(prm1)-Benzoylphenyl)propionic acid [R-(-)-ketoprofen] was produced from racemic 2-(3(prm1)-benzoylphenyl)propionamide (keto-amide) by the isolated bacterial strain Comamonas acidovorans KPO-2771-4. Sodium fumarate as the carbon source and 2-azacyclononanone or isobutyronitrile as the enhancer in the culture medium were effective for bacterial growth and the enhancement of R-(-)-ketoprofen-producing activity. R-(-)-Ketoprofen produced from the keto-amide by resting cells was present...

  5. Tuning the thermoresponsive properties of Hyperbranched Poly(ester amide)s based on diisopropanolamine and cyclic dicarboxylic anhydrides

    Kelland, Malcolm

    2011-01-01

    A range of water-soluble hyperbranched poly(ester amide)s has been synthesized with a view to studying their thermoresponsive behavior in water. Poly(ester amide)s with lower critical solution temperature (LCST) values around physiological temperatures are of interest for biological and medical applications, whereas poly(ester amide)s with high LCST values may be useful as kinetic hydrate inhibitors for high salinity produced fluids in the oil and gas industry. The LCST of these p...

  6. The design, synthesis of amide KARI inhibitors and their biological activities

    Baolei WANG; Yi MA; Yonghong LI; Suhua WANG; Zhengming LI

    2009-01-01

    Ketol-acid reductoisomerase(KARI) is a promising target for the design of herbicides yet there are only few reports on the molecular design of KARI inhibitors. In this paper, based on the reported 0.165 nm high resolution crystal structure of the spinach KARI complex, 279 molecules with low binding energy toward KARI were obtained from an MDL/ACD 3D database search using the program DOCK 4.0. According to the structural information of 279 molecules provided, some amide compounds have been designed and synthesized. The bioassay results show that most of these amides had inhibitory activity to rice KARI at a test concentration of 200 μg/mL. Among which eight amides, compounds 1 and 6 show 57.4% and 48.1% inhibitory activity to KARI. The herbicidal activities of these amides were further investigated on di-cotyledonous rape (Brassica campestris) and mono-cotyledonous bar-nyardgrass (Echinochloa crusgalli). Compounds 1 and 6 were more favorable than others and showed 52.0% and 72.6% inhibitory activity on rape root at 100 μg/mL concentration, respectively. These amides could be further optimized for finding more potent candidates.

  7. Epoxide hydrolase of Trichoderma reesei: Biochemical properties and conformational characterization.

    de Oliveira, Gabriel Stephani; Adriani, Patricia Pereira; Borges, Flavia Garcia; Lopes, Adriana Rios; Campana, Patricia T; Chambergo, Felipe S

    2016-08-01

    Epoxide hydrolases (EHs) are enzymes that are present in all living organisms and catalyze the hydrolysis of epoxides to the corresponding vicinal diols. EHs have biotechnological potential in chiral chemistry. We report the cloning, purification, enzymatic activity, and conformational analysis of the TrEH gene from Trichoderma reesei strain QM9414 using circular dichroism spectroscopy. The EH gene has an open reading frame encoding a protein of 343 amino acid residues, resulting in a molecular mass of 38.2kDa. The enzyme presents an optimum pH of 7.2, and it is highly active at temperatures ranging from 23 to 50°C and thermally inactivated at 70°C (t1/2=7.4min). The Michaelis constants (Km) were 4.6mM for racemic substrate, 21.7mM for (R)-(+)-styrene oxide and 3.0mM for (S)-(-)-styrene oxide. The kcat/Km analysis indicated that TrEH is enantioselective and preferentially hydrolyzes (S)-(-)-styrene oxide. The conformational stability studies suggested that, despite the extreme conditions (high temperatures and extremely acid and basic pHs), TrEH is able to maintain a considerable part of its regular structures, including the preservation of the native cores in some cases. The recombinant protein showed enantioselectivity that was distinct from other fungus EHs, making this protein a potential biotechnological tool. PMID:27177457

  8. Discovery of enantioselectivity of urea inhibitors of soluble epoxide hydrolase.

    Manickam, Manoj; Pillaiyar, Thanigaimalai; Boggu, PullaReddy; Venkateswararao, Eeda; Jalani, Hitesh B; Kim, Nam-Doo; Lee, Seul Ki; Jeon, Jang Su; Kim, Sang Kyum; Jung, Sang-Hun

    2016-07-19

    Soluble epoxide hydrolase (sEH) hydrolyzes epoxyeicosatrienoic acids (EETs) in the metabolic pathway of arachidonic acid and has been considered as an important therapeutic target for chronic diseases such as hypertension, diabetes and inflammation. Although many urea derivatives are known as sEH inhibitors, the enantioselectivity of the inhibitors is not highlighted in spite of the stereoselective hydrolysis of EETs by sEH. In an effort to explore the importance of enantioselectivity in the urea scaffold, a series of enantiomers with the stereocenter adjacent to the urea nitrogen atom were prepared. The selectivity of enantiomers of 1-(α-alkyl-α-phenylmethyl)-3-(3-phenylpropyl)ureas showed wide range differences up to 125 fold with the low IC50 value up to 13 nM. The S-configuration with planar phenyl and small alkyl groups at α-position is crucial for the activity and selectivity. However, restriction of the free rotation of two α-groups with indan-1-yl or 1,2,3,4-tetrahydronaphthalen-1-yl moiety abolishes the selectivity between the enantiomers, despite the increase in activity up to 13 nM. The hydrophilic group like sulfonamido group at para position of 3-phenylpropyl motif of 1-(α-alkyl-α-phenylmethyl-3-(3-phenylpropyl)urea improves the activity as well as enantiomeric selectivity. All these ureas are proved to be specific inhibitor of sEH without inhibition against mEH. PMID:27092411

  9. Disrupting Dimerization Translocates Soluble Epoxide Hydrolase to Peroxisomes.

    Jonathan W Nelson

    Full Text Available The epoxyeicosatrienoic acid (EET neutralizing enzyme soluble epoxide hydrolase (sEH is a neuronal enzyme, which has been localized in both the cytosol and peroxisomes. The molecular basis for its dual localization remains unclear as sEH contains a functional peroxisomal targeting sequence (PTS. Recently, a missense polymorphism was identified in human sEH (R287Q that enhances its peroxisomal localization. This same polymorphism has also been shown to generate weaker sEH homo-dimers. Taken together, these observations suggest that dimerization may mask the sEH PTS and prevent peroxisome translocation. In the current study, we test the hypothesis that dimerization is a key regulator of sEH subcellular localization. Specifically, we altered the dimerization state of sEH by introducing substitutions in amino acids responsible for the dimer-stabilizing salt-bridge. Green Fluorescent Protein (GFP fusions of each of mutants were co-transfected into mouse primary cultured cortical neurons together with a PTS-linked red fluorescent protein to constitutively label peroxisomes. Labeled neurons were analyzed using confocal microscopy and co-localization of sEH with peroxisomes was quantified using Pearson's correlation coefficient. We find that dimer-competent sEH constructs preferentially localize to the cytosol, whereas constructs with weakened or disrupted dimerization were preferentially targeted to peroxisomes. We conclude that the sEH dimerization status is a key regulator of its peroxisomal localization.

  10. Direct Lactamization of Azido Amides via Staudinger-Type Reductive Cyclization

    Heo, In Jung; Lee, Su Jeong; Cho, Chang Woo [Kyungpook National University, Daegu (Korea, Republic of)

    2012-01-15

    The direct lactamization of 1,3- and 1,4-azido amides has been achieved using triphenylphosphine and water, affording various γ- and δ-lactams in good to excellent yields. The direct lactamization of the azido amides was performed via the Staudinger-type reductive cyclization in which the amide group acts as the electrophile for lactam synthesis. This lactamization provides a mild, functional group tolerant and efficient route for the synthesis of various γ- and δ-lactams found in natural products and pharmaceuticals. Further studies will be conducted to develop new synthetic routes for the synthesis of various lactams. The lactam ring system is one of the most ubiquitous structural motifs found in natural products and pharmaceuticals. Owing to the prevalence of lactams, their synthesis has attracted considerable attention. Lactams are usually prepared by the coupling of activated carboxylic acid derivatives with amines. Alternative routes include the Beckmann rearrangement of oximes, the Schmidt reaction of cyclic ketones and hydrazoic acid, the Kinugasa reaction of nitrones and terminal acetylenes, the Diels-Alder reaction of cyclopentadiene and chlorosulfonyl isocyanate, transition metal catalyzed lactamization of amino alcohols, and iodolactamization of amides and alkenes. In particular, the intramolecular Staudinger ligation of azides and activated carboxy acids, including esters, is well known as an environmentally friendly and mild protocol for lactam synthesis.

  11. Direct Lactamization of Azido Amides via Staudinger-Type Reductive Cyclization

    The direct lactamization of 1,3- and 1,4-azido amides has been achieved using triphenylphosphine and water, affording various γ- and δ-lactams in good to excellent yields. The direct lactamization of the azido amides was performed via the Staudinger-type reductive cyclization in which the amide group acts as the electrophile for lactam synthesis. This lactamization provides a mild, functional group tolerant and efficient route for the synthesis of various γ- and δ-lactams found in natural products and pharmaceuticals. Further studies will be conducted to develop new synthetic routes for the synthesis of various lactams. The lactam ring system is one of the most ubiquitous structural motifs found in natural products and pharmaceuticals. Owing to the prevalence of lactams, their synthesis has attracted considerable attention. Lactams are usually prepared by the coupling of activated carboxylic acid derivatives with amines. Alternative routes include the Beckmann rearrangement of oximes, the Schmidt reaction of cyclic ketones and hydrazoic acid, the Kinugasa reaction of nitrones and terminal acetylenes, the Diels-Alder reaction of cyclopentadiene and chlorosulfonyl isocyanate, transition metal catalyzed lactamization of amino alcohols, and iodolactamization of amides and alkenes. In particular, the intramolecular Staudinger ligation of azides and activated carboxy acids, including esters, is well known as an environmentally friendly and mild protocol for lactam synthesis

  12. Synthesis and characterization of poly(ester amide from remewable resources through melt polycondensation

    B. B. Wang

    2014-01-01

    Full Text Available Biodegradable poly(ester amides (PEAs were synthesized from lactic acid and 11-aminoundecanoic acid via melt polycondensation. Molecular weights, chemical structures and thermal properties of the poly(ester amides were characterized in terms of gel permeation chromatography (GPC, Fourier transform infrared spectroscopy (FTIR, 1H nuclear magnetic resonance (1H NMR, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA, respectively. The PEAs have low molecular weights and display a lower cold crystallization temperature as well as smaller crystallinity by comparison with the pure poly(lactic acid (PLA. The incorporation of the 11-aminoundecanoic acid into the PLA chain not only improved the thermal stability but changed the decomposition process.

  13. Steroids linked with amide bond

    Černý, Ivan; Buděšínský, Miloš; Drašar, P.; Pouzar, Vladimír

    Dublin : University Cillege Dublin, 2007. s. 115. [European Symposium on Organic Chemistry /15./. 08.07.2007-13.07.2007, Dublin] R&D Projects: GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z40550506 Keywords : bis- steroids * etienic acid * cholesteryl amine Subject RIV: CC - Organic Chemistry

  14. Variation of protein backbone amide resonance by electrostatic field

    Sharley, John N.

    2015-01-01

    Amide resonance is found to be sensitive to electrostatic field with component parallel or antiparallel the amide C-N bond. This effect is linear and without threshold in the biologically plausible electrostatic field range -0.005 to 0.005 au. Variation of amide resonance varies Resonance-Assisted Hydrogen Bonding such as occurs in the hydrogen bonded chains of backbone amides of protein secondary structures such as beta sheet and alpha helix, varying the stability of the secondary structure....

  15. Steroids linked with amide bond - extended cholesterol

    Černý, Ivan; Buděšínský, Miloš; Pouzar, Vladimír; Drašar, P.

    2009-01-01

    Roč. 74, č. 1 (2009), s. 88-94. ISSN 0039-128X R&D Projects: GA MŠk(CZ) LC06077; GA AV ČR KAN200200651 Institutional research plan: CEZ:AV0Z40550506 Keywords : synthesis * oligomers * amides Subject RIV: CC - Organic Chemistry Impact factor: 2.905, year: 2009

  16. Efficient Amide Based Halogenide Anion Receptors

    Hong Xing WU; Feng Hua LI; Hai LIN; Shou Rong ZHU; Hua Kuan LIN

    2005-01-01

    In this paper, we present the synthesis and anion recognition properties of the amide based phenanthroline derivatives 1, 2 and 3. In all cases 1:1 receptor: anion complexes were observed. The receptors were found to be selective for fluoride and chloride respectively over other putative anionic guest species.

  17. Re-characterization of mono-2-ethylhexyl phthalate hydrolase belonging to the serine hydrolase family.

    Iwata, Makoto; Imaoka, Takuya; Nishiyama, Takashi; Fujii, Takao

    2016-08-01

    A novel bacterium assimilating di-2-ethylhexyl phthalate as a sole carbon source was isolated, and identified as a Rhodococcus species and the strain was named EG-5. The strain has a mono-2-ethylhexyl phthalate (MEHP) hydrolase (EG-5 MehpH), which exhibits some different enzymatic features when compared with the previously reported MEHP hydrolase (P8219 MehpH) from Gordonia sp. These differences include different pH optimum activity, maximal reaction temperature and heat stability. The Km and Vmax values of EG-5 MehpH were significantly higher than those of P8219 MehpH. The primary structure of EG-5 MehpH showed the highest sequence identity to that of P8219 MehpH (39%) among hydrolases. The phylogenetic tree suggested that EG-5 MehpH and P8219 MehpH were categorized in different groups of the novel MEHP hydrolase family. Mutation of a conserved R(109) residue of EG-5 MehpH to a hydrophobic residue resulted in a dramatic reduction in the Vmax value towards MEHP without affecting the Km value. These results indicate that this residue may neutralize the negative charge of a carboxylate anion of MEHP, and thus inhibit the catalytic nucleophile from attacking the ester bond. In other words, the R residue blocks inhibition from the carboxylate anion of MEHP. Recently, registered hypothetical proteins exhibiting 98% or 99% identities for EG-5 MehpH or for P8219 MehpH were found from some pathogens belonging to Actinomycetes. The protein may have other activities besides MEHP hydrolysis and function in other physiological reactions in some Actinomycetes. PMID:26868518

  18. Purification, crystallization and preliminary crystallographic studies of plant S-adenosyl-l-homocysteine hydrolase (Lupinus luteus)

    Single crystals of recombinant S-adenosyl-l-homocysteine hydrolase from L. luteus in complex with adenosine diffract X-rays to 1.17 Å resolution at 100 K. The crystals are tetragonal, space group P43212, and contain one copy of the dimeric enzyme in the asymmetric unit. By degrading S-adenosyl-l-homocysteine, which is a byproduct of S-adenosyl-l-methionine-dependent methylation reactions, S-adenosyl-l-homocysteine hydrolase (SAHase) acts as a regulator of cellular methylation processes. S-Adenosyl-l-homocysteine hydrolase from the leguminose plant yellow lupin (Lupinus luteus), LlSAHase, which is composed of 485 amino acids and has a molecular weight of 55 kDa, has been cloned, expressed in Escherichia coli and purified. Crystals of LlSAHase in complex with adenosine were obtained by the hanging-drop vapour-diffusion method using 20%(w/v) PEG 4000 and 10%(v/v) 2-propanol as precipitants in 0.1 M Tris–HCl buffer pH 8.0. The crystals were tetragonal, space group P43212, with unit-cell parameters a = 122.4, c = 126.5 Å and contained two protein molecules in the asymmetric unit, corresponding to the functional dimeric form of the enzyme. Atomic resolution (1.17 Å) X-ray diffraction data have been collected using synchrotron radiation

  19. Discovery of a Novel Microsomal Epoxide Hydrolase-Catalyzed Hydration of a Spiro Oxetane.

    Li, Xue-Qing; Hayes, Martin A; Grönberg, Gunnar; Berggren, Kristina; Castagnoli, Neal; Weidolf, Lars

    2016-08-01

    Oxetane moieties are increasingly being used by the pharmaceutical industry as building blocks in drug candidates because of their pronounced ability to improve physicochemical parameters and metabolic stability of drug candidates. The enzymes that catalyze the biotransformation of the oxetane moiety are, however, not well studied. The in vitro metabolism of a spiro oxetane-containing compound AZD1979 [(3-(4-(2-oxa-6-azaspiro[3.3]heptan-6-ylmethyl)phenoxy)azetidin-1-yl)(5-(4-ethoxyphenyl)-1,3,4-oxadiazol-2-yl)methanone] was studied and one of its metabolites, M1, attracted our interest because its formation was NAD(P)H independent. The focus of this work was to elucidate the structure of M1 and to understand the mechanism(s) of its formation. We established that M1 was formed via hydration and ring opening of the oxetanyl moiety of AZD1979. Incubations of AZD1979 using various human liver subcellular fractions revealed that the hydration reaction leading to M1 occurred mainly in the microsomal fraction. The underlying mechanism as a hydration, rather than an oxidation reaction, was supported by the incorporation of (18)O from H2 (18)O into M1. Enzyme kinetics were performed probing the formation of M1 in human liver microsomes. The formation of M1 was substantially inhibited by progabide, a microsomal epoxide hydrolase inhibitor, but not by trans-4-[4-(1-adamantylcarbamoylamino)cyclohexyloxy]benzoic acid, a soluble epoxide hydrolase inhibitor. On the basis of these results, we propose that microsomal epoxide hydrolase catalyzes the formation of M1. The substrate specificity of microsomal epoxide hydrolase should therefore be expanded to include not only epoxides but also the oxetanyl ring system present in AZD1979. PMID:27256986

  20. Molecular Cloning of a Novel cDNA From Mus Muscular BALB/c Mice Encoding Glycosyl Hydrolase Family 1: A Homolog of HumanLactase-Phlorizin Hydrolase

    WEI HE; ZHEN-YU JI; CHENG-YU HUANG

    2006-01-01

    Objective To study the mechanism of lactose intolerance (LI) by cloning the mouse lactase cDNA and recombining a vector. Methods Total murine RNA was isolated from the small intestine of a 4-week-old BALB/c mouse (♂).Gene-specific primers were designed and synthesized according to the cDNA sequences of lactase-phlorizin hydrolase (LPH) in human, rat, and rabbit. A coding sequence (CDS) fragment was obtained using RT-PCR, and inserted into a clone vector pNEB-193, then the cDNA was sequenced and analyzed using bioinformatics. Results The cDNA from the BALB/c mouse with 912 bp encoding 303 amino acid residues. Analysis of the deduced amino acid sequence using bioinformatics revealed that this cDNA shared extensive sequence homology with human LPH containing a conserved glycosy1 hydrolase family 1 motif important for regulating lactase intolerance. Conclusion BALB/c mouse LPH cDNA (GenBank accession No: AY751548) provides a necessary foundation for study of the biological function and regulatory mechanism of the lactose intolerance in mice.

  1. Simultaneous NMR assignment of backbone and side chain amides in large proteins with IS-TROSY

    A new strategy for the simultaneous NMR assignment of both backbone and side chain amides in large proteins with isotopomer-selective transverse-relaxation-optimized spectroscopy (IS-TROSY) is reported. The method considers aspects of both the NMR sample preparation and the experimental design. First, the protein is dissolved in a buffer with 50%H2O/50%D2O in order to promote the population of semideuterated NHD isotopomers in side chain amides of Asn/Gln residues. Second, a 13C'-coupled 2D 15N-1H IS-TROSY spectrum provides a stereospecific distinction between the geminal protons in the E and Z configurations of the carboxyamide group. Third, a suite of IS-TROSY-based triple-resonance NMR experiments, e.g. 3D IS-TROSY-HNCA and 3D IS-TROSY-HNCACB, are designed to correlate aliphatic carbon atoms with backbone amides and, for Asn/Gln residues, at the same time with side chain amides. The NMR assignment procedure is similar to that for small proteins using conventional 3D HNCA/3D HNCACB spectra, in which, however, signals from NH2 groups are often very weak or even missing due to the use of broad-band proton decoupling schemes and NOE data have to be used as a remedy. For large proteins, the use of conventional TROSY experiments makes resonances of side chain amides not observable at all. The application of IS-TROSY experiments to the 35-kDa yeast cytosine deaminase has established a complete resonance assignment for the backbone and stereospecific assignment for side chain amides, which otherwise could not be achieved with existing NMR experiments. Thus, the development of IS-TROSY-based method provides new opportunities for the NMR study of important structural and biological roles of carboxyamides and side chain moieties of arginine and lysine residues in large proteins as well as amino moieties in nucleic acids

  2. Changes in brain levels of N-acylethanolamines and 2-arachidonoylglycerol in focal cerebral ischemia in mice

    Degn, Matilda; Lambertsen, Kate L.; Petersen, Gitte;

    2007-01-01

    induction of ischemia. Accumulation of NAEs did not depend on regulation of N-acylphosphatidylethanolamine-hydrolyzing phospholipase D or fatty acid amide hydrolase. Treatment with the fatty acid amide hydrolase inhibitor URB597 (cyclohexyl carbamic acid 3'-carbamoyl-biphenyl-3-yl ester; 1 mg/kg; i.p.) 1...

  3. Investigation of the Bacillus cereus phosphonoacetaldehyde hydrolase catalytic mechanism

    The enzyme phosphonoacetaldehyde hydrolase (phosphonatase) from Bacillus cereus catalyzes the conversion of phosphonoacetaldehyde and phosphate. We have demonstrated that phosphonatase is inactivated when incubated with either acetaldehyde or phosphonoacetaldehyde for short time periods at low temperature in the presence of NaBH4. This result suggests that the Schiff base mechanism is operative since such treatment might be expected to inactivate the enzyme by reducing an iminium cation mechanistic intermediate. The inactivation process was shown to be highly specific for a single lysine residue. Incubation of phosphonatase with [3H]-NaBH4 and phosphonacetaldehyde [14C]-acetaldehyde and NaBH4 or [C2-3H]- phosphonoacetaldehyde and NaBH4 resulted in radiolabeled inactivated enzyme. Tryptic hydrolysis and reverse phase HPLC chromatography of the resulting digests demonstrated that the [C2 - 3H]- phosphonoacetaldehyde/NaBH4 methodology afforded the most specifically tritium labeled, inactivated phosphonatase. The radiolabeled, active site peptide was purified to homogeneity and its amino acid sequence was determined

  4. Expression of Nudix hydrolase genes in barley under UV irradiation

    Tanaka, Sayuri; Sugimoto, Manabu; Kihara, Makoto

    Seed storage and cultivation should be necessary to self-supply foods when astronauts would stay and investigate during long-term space travel and habitation in the bases on the Moon and Mars. Thought the sunlight is the most importance to plants, both as the ultimate energy source and as an environmental signal regulating growth and development, UV presenting the sunlight can damage many aspects of plant processes at the physiological and DNA level. Especially UV-C, which is eliminated by the stratospheric ozone layer, is suspected to be extremely harmful and give a deadly injury to plants in space. However, the defense mechanism against UV-C irradiation damage in plant cells has not been clear. In this study, we investigated the expression of Nudix hydrolases, which defense plants from biotic / abiotic stress, in barley under UV irradiation. The genes encoding the amino acid sequences, which show homology to those of 28 kinds of Nudix hydrolases in Arabidopsis thaliana, were identified in the barley full-length cDNA library. BLAST analysis showed 14 kinds of barley genes (HvNUDX1-14), which encode the Nudix motif sequence. A phylogenetic tree showed that HvNUDX1, HvNUDX7, HvNUDX9 and HvNUDX11 belonged to the ADP-ribose pyrophosphohydrolase, ADP-sugar pyrophosphohydrolase, NAD(P)H pyrophosphohydrolase and FAD pyrophosphohydrolase subfamilies, respectively, HvNUDX3, HvNUDX6, and HvNUDX8 belonged to the Ap _{n}A pyrophosphohydrolase subfamilies, HvNUDX5 and HvNUDX14 belonged to the coenzyme A pyrophosphohydrolase subfamilies, HvNUDX12 and HvNUDX13 belonged to the Ap _{4}A pyrophosphohydrolase subfamilies. Induction of HvNUDX genes by UV-A (340nm), UV-B (312nm), and UV-C (260nm) were analyzed by quantitative RT-PCR. The results showed that HvNUDX4 was induced by UV-A and UV-B, HvNUDX6 was induced by UV-B and UV-C, and HvNUDX7 and HvNUDX14 were induced by UV-C, significantly. Our results suggest that the response of HvNUDXs to UV irradiation is different by UV

  5. Novel microbial epoxide hydrolases for biohydrolysis of glycidyl derivatives

    Kotík, Michael; Břicháč, Jiří; Kyslík, Pavel

    2005-01-01

    Roč. 120, - (2005), s. 364-375. ISSN 0168-1656 Institutional research plan: CEZ:AV0Z5020903 Keywords : screening * epoxide hydrolase * biotransformation Subject RIV: EE - Microbiology, Virology Impact factor: 2.687, year: 2005

  6. N-acetylglucosamine-1-Phosphate Transferase Suppresses Lysosomal Hydrolases in Dysfunctional Osteoclasts: A Potential Mechanism for Vascular Calcification

    Yang Lei

    2015-04-01

    Full Text Available In addition to increased differentiation of vascular smooth muscle cells into osteoblast-like phenotypes, the limited accumulation of osteoclasts in atherosclerotic plaques or their dysfunction may participate in potential mechanisms for vascular calcification. N-acetylglucosamine-1-phosphate transferase containing alpha and beta subunits (GNPTAB is a transmembrane enzyme complex that mediates the vesicular transport of lysosomal hydrolases. GNPTAB may also regulate the biogenesis of lysosomal hydrolases from bone-marrow derived osteoclasts. In this study, the areas surrounding calcification in human atherosclerotic plaques contained high levels of GNPTAB and low levels of lysosomal hydrolases such as cathepsin K (CTSK and tartrate-resistant acid phosphatase (TRAP, as demonstrated by immunohistochemistry and laser-capture microdissection-assisted mRNA expression analysis. We therefore hypothesized that GNPTAB secretion may suppress the release of CTSK and TRAP by vascular osteoclast-like cells, thus causing their dysfunction and reducing the resorption of calcification. We used human primary macrophages derived from peripheral blood mononuclear cells, an established osteoclast differentiation model. GNPTAB siRNA silencing accelerated the formation of functional osteoclasts as detected by increased secretion of CTSK and TRAP and increased their bone resorption activity as gauged by resorption pits assay. We concluded that high levels of GNPTAB inhibit secretion of lysosomal hydrolases in dysfunctional osteoclasts, thereby affecting their resorption potential in cardiovascular calcification.

  7. Further characterization of intestinal lactase/phlorizin hydrolase

    Skovbjerg, H; Norén, O; Sjöström, H;

    1982-01-01

    enzyme were shown to have a considerable activity against cellotriose and cellotetraose, and a low but significant activity against cellulose. The lactase/phlorizin hydrolase isolated from pigs in which the pancreatic ducts had been disconnected 3 days before death and from Ca2+-precipitated enterocyte...... membranes (basolateral and intracellular membranes) exhibited in SDS-polyacrylamide gel electrophoresis the same size of constituent polypeptides and the same catalytic and immunological properties as a normal brush border lactase/phlorizin hydrolase....

  8. Synthesis and pharmacological evaluation of antiinflammatory mutual amide prodrugs

    D T Makhija

    2013-01-01

    Full Text Available Nonsteroidal antiinflammatory drugs have been widely used for the management of inflammation, pain and nociception. Gastric intolerance caused by most of the nonsteroidal antiinflammatory drugs used today restricts their use. Several approaches have been proposed to modify the parent nonsteroidal antiinflammatory drugs molecule in order to reduce their gastric toxicity. Oral prodrug approach is one of such approaches. In the present work three nonsteroidal antiinflammatory drugs viz. ibuprofen, diclofenac, and flurbiprofen were conjugated with sulfonamides like sulphamethoxazole and sulphanilamide via amide bond using dicyclohexylcarbodiimide coupling reaction. The synthesized prodrugs were screened for their analgesic and antiinflammatory activity using Eddy′s hot plate, acetic acid-induced writhing and carrageenan-induced rat paw edema method, respectively. These prodrugs were also evaluated for their ulcerogenic potential. All synthesized prodrugs were found to be less ulcerogenic than their parent nonsteroidal antiinflammatory drugs and showed better activity profile in terms of analgesic and antiinflammatory activity as compared to their respective parent drugs.

  9. Development of organophosphate hydrolase activity in a bacterial homolog of human cholinesterase

    Patricia Marie Legler; Susanne eBoisvert; Compton, Jaimee R.; Millard, Charles B.

    2014-01-01

    We applied a combination of rational design and directed evolution (DE) to Bacillus subtilis p-nitrobenzyl esterase (pNBE) with the goal of enhancing organophosphorus acid anhydride hydrolase (OPAAH) activity. DE started with a designed variant, pNBE A107H, carrying a histidine homologous with human butyrylcholinesterase G117H to find complementary mutations that further enhance its OPAAH activity. Five sites were selected (G105, G106, A107, A190, and A400) within a 6.7 Å radius of the nucl...

  10. Development of organophosphate hydrolase activity in a bacterial homolog of human cholinesterase

    Legler, Patricia M.; Boisvert, Susanne M.; Compton, Jaimee R.; Millard, Charles B.

    2014-01-01

    We applied a combination of rational design and directed evolution (DE) to Bacillus subtilis p-nitrobenzyl esterase (pNBE) with the goal of enhancing organophosphorus acid anhydride hydrolase (OPAAH) activity. DE started with a designed variant, pNBE A107H, carrying a histidine homologous with human butyrylcholinesterase G117H to find complementary mutations that further enhance its OPAAH activity. Five sites were selected (G105, G106, A107, A190, and A400) within a 6.7 Å radius of the nucleo...

  11. CORROSION INHIBITION OF CASSAVA STARCH GRAFT ACRYL AMIDE COPOLYMER FOR COLD ROLLED STEEL IN HYDROCHLORIC ACID%木薯淀粉接枝共聚物在盐酸介质中对冷轧钢的缓蚀作用

    付惠; 李向红; 李云仙; 刘建祥

    2011-01-01

    采用氧化还原引发体系引发木薯淀粉与丙烯酰胺接枝共聚反应制备的天然木薯淀粉接枝共聚物(SGA),可以作为一种环境友好型“绿色”缓蚀剂。本文用失重法、动电位极化曲线、电化学阻抗(EIS)和扫描电子显微镜(SEM)首次研究了SGA在1.0mol/LHCl溶液中对冷轧钢的缓蚀作用。结果表明,SGA对冷轧钢具有良好的缓蚀作用,在钢表面的吸附符合Langmuir吸附等温式,为混合抑制型缓蚀剂;EIS谱呈半圆容抗弧,电荷转移电阻随缓蚀剂浓度的增加而增大。SEM表明SGA在钢表面吸附形成了致密的缓蚀剂膜层。%Cassava starch graft acryl amide copolymer (SGA) was prepared by grafting acryl amide onto starch with oxidization reduction reaction, which can be used as a good environmentally-friendly "green" inhibitor. The inhibition effect of SGA on the corrosion of cold rolled steel (CRS) in 1.0 mol/L HCl has been studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) methods. The results show that SGA is a good inhibitor in 1.0 mol/L HC1 for CRS, and the adsorption of SGA on the CRS surface obeys Langmuir adsorption isotherm. Polarization curves show that SGA is a mixed-type inhibitor in hydrochloric acid. All EIS spectra exhibit one capacitive loop, and the charge transfer resistance increases with the inhibitor concentration. SEM results show that the introduction of SGA into HCl solution results in the formation of a compact and dense inhibitive film on the CRS surface.

  12. Conformational analysis of amide extractants by NMR in organic phase

    This study deals with nuclear fuel reprocessing. We have essentially used NMR spectroscopy. We want to understand which kind of conformational parameters control selectivity and efficiency of amide extractant. The symmetric monoamides used are DOBA (C3H7 CON (CH2 CH(C2H5) C4H9)2), DOiBA ((CH3)2 CCHON (CH2CH(C2H5)C4H9)2) and DOTA ((CH3)3 CCH2CON(CH2CH(C2H5)C4H9)2). Each gives two quasi equivalent conformers (cis and trans) in organic phases. The selected malonamide DMDBTDMA ((C4H9 (CH3)NCO)2 CHC14H29) has four conformers because of its twice disymmetric amide functions. Weak interactions between monoamides which yield to dimer formation. The malonamide also gives dimers but forms aggregates too. Nitric acid extraction is due to the competitive formation of six species L, L2, L2(HNO3), L(HNO3), L(HNO3)2, L(HNO3)3 (L: monoamide). Complexation between lanthanides (III) and monoamides yields to the stoichiometries L3Ln(NO3)3 and L2Ln(NO3)3. Their ratio depend of steric hindrance on the carbonyl and the metal ionic radius. The same thing is observed of Pu4+ and Th4+ extraction in non acidic media. L2An(NO3)4 is the main stoichiometric except for the Th4+ - DOBA system where the species (DOBA)3 Th(NO3)4 appear. Exchange rates between the ligand and the complex are pointed out. The monoamide conformations obtained with lanthanide and plutonium nitrate can explain the difference in extracting power of this molecule between An4+ and Ln3+. (author). 162 refs., 87 figs., 44 tabs., 7 annexes

  13. Synthesis, characterization and pharmacological evaluation of amide prodrugs of Flurbiprofen

    Flurbiprofen (FB) suffers from the general side effects of NSAIDs, owing to presence of free carboxylic acid group. The study was aimed to retard the adverse effects of gastrointestinal origin. Ten prodrugs of FB were synthesized by amidation with ethyl esters of amino acids, namely, glycine, L-phenylalanine, L-tryptophan, L-valine, L-isoleucine, L-alanine, L-leucine, L-glutamic acid, L-aspartic acid and β alanine. Purified synthesized prodrugs were characterized by m.p., TLC, solubility, partition coefficients, elemental analyses, UV, FTIR, NMR and MS. Synthesized prodrugs were subjected for bioavailability studies, analgesic, anti-inflammatory activities and ulcerogenic index. Marked reduction of ulcerogenic index and comparable analgesic, antiinflammatory activities were obtained in all cases as compared to FB. Among synthesized prodrugs AR-9, AR-10 and AR-2 showing excellent pharmacological response and encouraging hydrolysis rate both in (Simulated Intestinal Fluid) SIF and in 80% human plasma. Prodrugs with increased aliphatic side chain length or introduction of aromatic substituent resulted in enhanced partition coefficient but diminished dissolution and hydrolysis rate. Such prodrugs can be considered for sustained release purpose. (author)

  14. Synthesis, characterization and pharmacological evaluation of amide prodrugs of Flurbiprofen

    Mishra, Ashutosh; Veerasamy, Ravichandran; Jain, Prateek Kumar; Dixit, Vinod Kumar; Agrawal, Ram Kishor [Dr. H. S. Gour Vishwavidyalaya, Sagar (India). Dept. of Pharmaceutical Sciences. Pharmaceutical Chemistry Research Lab.]. E-mail: dragrawal2001@yahoo.co.in

    2008-07-01

    Flurbiprofen (FB) suffers from the general side effects of NSAIDs, owing to presence of free carboxylic acid group. The study was aimed to retard the adverse effects of gastrointestinal origin. Ten prodrugs of FB were synthesized by amidation with ethyl esters of amino acids, namely, glycine, L-phenylalanine, L-tryptophan, L-valine, L-isoleucine, L-alanine, L-leucine, L-glutamic acid, L-aspartic acid and {beta} alanine. Purified synthesized prodrugs were characterized by m.p., TLC, solubility, partition coefficients, elemental analyses, UV, FTIR, NMR and MS. Synthesized prodrugs were subjected for bioavailability studies, analgesic, anti-inflammatory activities and ulcerogenic index. Marked reduction of ulcerogenic index and comparable analgesic, antiinflammatory activities were obtained in all cases as compared to FB. Among synthesized prodrugs AR-9, AR-10 and AR-2 showing excellent pharmacological response and encouraging hydrolysis rate both in (Simulated Intestinal Fluid) SIF and in 80% human plasma. Prodrugs with increased aliphatic side chain length or introduction of aromatic substituent resulted in enhanced partition coefficient but diminished dissolution and hydrolysis rate. Such prodrugs can be considered for sustained release purpose. (author)

  15. Molecular cloning, expression and characterization of acylpeptide hydrolase in the silkworm, Bombyx mori.

    Fu, Ping; Sun, Wei; Zhang, Ze

    2016-04-10

    Acylpeptide hydrolase (APH) can catalyze the release of the N-terminal amino acid from acetylated peptides. There were many documented examples of this enzyme in various prokaryotic and eukaryotic organisms. However, knowledge about APH in insects still remains unknown. In this study, we cloned and sequenced a putative silkworm Bombyx mori APH (BmAPH) gene. The BmAPH gene encodes a protein of 710 amino acids with a predicted molecular mass of 78.5kDa. The putative BmAPH and mammal APHs share about 36% amino acid sequence identity, yet key catalytic residues are conserved (Ser566, Asp654, and His686). Expression and purification of the recombinant BmAPH in Escherichia coli showed that it has acylpeptide hydrolase activity toward the traditional substrate, Ac-Ala-pNA. Furthermore, organophosphorus (OP) insecticides, chlorpyrifos, phoxim, and malathion, significantly inhibited the activity of the APH both in vitro and in vivo. In addition, BmAPH was expressed in all tested tissues and developmental stages of the silkworm. Finally, immunohistochemistry analysis showed that BmAPH protein was localized in the basement membranes. These results suggested that BmAPH may be involved in enhancing silkworm tolerance to the OP insecticides. In a word, our results provide evidence for understanding of the biological function of APH in insects. PMID:26778207

  16. Synthesis and Evaluation of Coumaroyl Dipeptide Amide as Potential Whitening Agents

    Kim, Jaeil; Lee, Jaeho [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Lee, Hyesuk; Shin, Kyonghoon; Ryu, Geunseog; Cho, Inshik; Kim, Hanyoung [Central Research Laboratories, Daejeon (Korea, Republic of)

    2013-10-15

    Coumaroyl dipeptide amide, Coumaric acid-LG-NH{sub 2}, was prepared successfully using the solid-phase method, and its efficacy as a skin whitening agent was studied. Coumaric acid-LG-NH{sub 2} was prepared with Rink-amide resin, and 96.354% of purity was obtained. Using MTT assay and LDH release assay, we found that it exhibited very low cytotoxicity. And, we found that Coumaric acid-LG-NH{sub 2} inhibited tyrosinase activity dose-dependently and showed superior tyrosinase inhibitory activity to well-known whitening agent, arbutin. IC{sub 50} value of Coumaric acid-LG-NH{sub 2} was 182.4 μM, and IC{sub 50} value of arbutin was 384.6 μM. Also, in measurement of melanin contents using B16F1 melanoma cell lines, Coumaric acid-LG-NH{sub 2} reduced melanin production induced by α-MSH statistically significant, and showed superior melanin inhibitory activity to p-coumaric acid or arbutin. In addition, Coumaric acid-LG-NH{sub 2} reduced MC1R mRNA expression level. Thus, we concluded that MC1R pathway is the significant pathway of Coumaric acid-LG-NH{sub 2}, and Coumaric acid-LG-NH{sub 2} has great potential to be used as novel whitening agents.

  17. Synthesis and Evaluation of Coumaroyl Dipeptide Amide as Potential Whitening Agents

    Coumaroyl dipeptide amide, Coumaric acid-LG-NH2, was prepared successfully using the solid-phase method, and its efficacy as a skin whitening agent was studied. Coumaric acid-LG-NH2 was prepared with Rink-amide resin, and 96.354% of purity was obtained. Using MTT assay and LDH release assay, we found that it exhibited very low cytotoxicity. And, we found that Coumaric acid-LG-NH2 inhibited tyrosinase activity dose-dependently and showed superior tyrosinase inhibitory activity to well-known whitening agent, arbutin. IC50 value of Coumaric acid-LG-NH2 was 182.4 μM, and IC50 value of arbutin was 384.6 μM. Also, in measurement of melanin contents using B16F1 melanoma cell lines, Coumaric acid-LG-NH2 reduced melanin production induced by α-MSH statistically significant, and showed superior melanin inhibitory activity to p-coumaric acid or arbutin. In addition, Coumaric acid-LG-NH2 reduced MC1R mRNA expression level. Thus, we concluded that MC1R pathway is the significant pathway of Coumaric acid-LG-NH2, and Coumaric acid-LG-NH2 has great potential to be used as novel whitening agents

  18. ADMINISTRATION OF A SUBSTITUTED ADAMANTLY-UREA INHIBITOR OF THE SOLUBLE EPOXIDE HYDROLASE PROTECTS THE KIDNEY FROM DAMAGE IN HYPERTENSIVE GOTO-KAKIZAKI RATS

    Hypertension and type II diabetes are co-morbid diseases that lead to the development of nephropathy. Soluble epoxide hydrolase (sEH) inhibitors are reported to provide protection from renal injury. We hypothesized that the sEH inhibitor 12-(3-adamantan-1-yl-ureido) dodecanoic acid (AUDA) protects ...

  19. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae: new amides and phenolic compounds

    Ana Lígia Leandrini de Oliveira

    2012-01-01

    Full Text Available This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl-benzamide (0.019% and N,4-dihydroxy-N-(2'-hydroxyethyl-benzeneacetamide (0.023%. These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family.

  20. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds

    This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family. (author)

  1. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds

    Oliveira, Ana Ligia Leandrini de; Silva, Denise B. da; Lopes, Norberto P.; Debonsi, Hosana M. [Universidade de Sao Paulo (FCFRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Ciencias Farmaceuticas de Ribeirao Preto. Dept. de Quimica e Fisica; Yokoya, Nair S., E-mail: hosana@fcfrp.usp.br [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Ficologia

    2012-07-01

    This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family. (author)

  2. Passive Membrane Permeability of Macrocycles Can Be Controlled by Exocyclic Amide Bonds.

    Hickey, Jennifer L; Zaretsky, Serge; St Denis, Megan A; Kumar Chakka, Sai; Morshed, M Monzur; Scully, Conor C G; Roughton, Andrew L; Yudin, Andrei K

    2016-06-01

    We have developed a strategy for synthesizing passively permeable peptidomimetic macrocycles. The cyclization chemistry centers on using aziridine aldehydes in a multicomponent reaction with peptides and isocyanides. The linker region in the resulting product contains an exocyclic amide positioned α to the peptide backbone, an arrangement that is not found among natural amino acids. This amide provides structural rigidity within the cyclic peptidomimetic and promotes the creation of a stabilizing intramolecular hydrogen bonding network. This exocyclic control element also contributes to the increased membrane permeability exhibited by multicomponent-derived macrocycles with respect to their homodetic counterparts. The exocyclic control element is employed along with a strategic placement of N-methyl and d-amino acids to produce passively permeable peptides, which contain multiple polar residues. This strategy should be applicable in the pursuit of synthesizing therapeutically relevant macrocycles. PMID:27120576

  3. Studies on novel interpenetrating networks of urethane modified poly(ester-amide and vinyl ester of bisphenol-C

    Pragnesh N. Dave

    2016-05-01

    Full Text Available Bisphthalamic acids were prepared by reaction of maleic anhydride and aromatic diamines. Novel poly(ester-amides (PEAs were prepared by reaction of DGEBF with bisphthalamic acids. Acrylation of PEAs was carried out using acryloyl chloride; products are called acrylated poly(ester-amides (APEAs. Epoxy resin based unsaturated poly(ester-amide resins (UPEAs can be prepared by many methods but here these were prepared by reported method. These UPEAs were then treated with acryloyl chloride to afford acrylated UPEAs resin (i.e. AUPEAs. Interpenetrating networks of equal proportional urethane modified poly(ester-amide and acrylated poly(ester-amide and vinyl ester of biaphenol c (VE resin were prepared. Urethane modified APEAs and AUPEAs were characterized by elemental analysis, molecular weight was determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA.

  4. Poly(ester-amide)s derived from PET containing uniform bisester amide segments

    Ascanio Nuñez, Yanireth

    2013-01-01

    Poly(ethylene terephthalate) has experienced a growth in its demand as a bottle container and food packaging material. However, in order to expand its uses, its barrier properties to gases like carbon dioxide and oxygen, have to be improved. In this way, bisester amide units have been introduced as a third component in the main chain of PET, with the aim to reduce both CO2 and O2 permeability. In this project, poly(ester-amide)s based on PET (PETxMXy) have been synthesized, according to th...

  5. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Vinyl Acetate

    Patel, H. S.; Panchal, K. K.; Patel, S. R.; Desai, S N

    2004-01-01

    Novel unsaturated poly (ester- amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Vinyl acetate (VA) to produce a homogeneous resin syrup. The curing of these UPEAs-VA resin blends was carried out by using benzoyl peroxide (BPO) as an initiator for the radical polymerization and was monitored by using ...

  6. Synthesis, in vitro antimalarial activity and cytotoxicity of novel 4-aminoquinolinyl-chalcone amides

    Smit, Frans J; N'Da, David D.

    2014-01-01

    A series of 4-aminoquinolinyl-chalcone amides 11–19 were synthesized through condensation of carboxylic acid-functionalized chalcone with aminoquinolines, using 1,10-carbonyldiimidazole as coupling agent. These compounds were screened against the chloroquine sensitive (3D7) and chloroquine resistant (W2) strains of Plasmodium falciparum. Their cytotoxicity towards the WI-38 cell line of normal human fetal lung fibroblast was determined. All compounds were found active, with IC50 v...

  7. New Polymeric Admixture for Cement Based on Hyperbranched Poly Amide-Ester with Pentaerythritol Core

    Amal Amin Ibrahim; Ahmed El-Sayed Abdel-Megied; Mohamed Sayed Selim; Hassan Hassenen Darweesh; Magdy Mohamed Ayoub

    2013-01-01

    Hyperbranched poly amide-ester (HBPAE) was synthesized by a solution condensation polymerization through one-step process using pentaerythritol as a central core and AB2 prepolymerized monomer which was rapidly prepared at room temperature (25°C) using commercially available maleic anhydride (MA) and diethanolamine (DEA) monomers in the presence of p-toluene sulfonic acid as a catalyst. The prepared polymer was characterized by GPC, IR, 1H-NMR, and thermal analysis (TGA and DSC). The influenc...

  8. Boophiline, an Antimicrobial Sterol Amide from the Cattle Tick Boophilus microplus

    Potterat, Olivier; Hostettmann, Kurt; Höltzel, Alexandra; Jung, Günther; Diehl, Peter A.; Petrini, Orlando

    2008-01-01

    Boophiline (1), a new sterol amide was isolated from the cattle tick Boophilus microplus (Ixodidae). The structure was assigned as N-[3-(sulfooxy)-25ξ-cholest-5-en-26-oyl]-L-isoleucine by detailed 2D NMR investigations in conjunction with FAB mass spectrometry and acidic hydrolyses. Complete assignment of the diastereotopic methylene protons of the ring system could be deduced from the NMR data. In agar dilution assays, 1 exhibited antifungal properties against Cladosporium cucumerinum and an...

  9. DNA-Catalyzed Hydrolysis of Esters and Aromatic Amides

    Brandsen, Benjamin M.; Hesser, Anthony R.; Castner, Marissa A.; Chandra, Madhavaiah; Silverman, Scott K.

    2013-01-01

    We previously reported that DNA catalysts (deoxyribozymes) can hydrolyze DNA phosphodiester linkages, but DNA-catalyzed amide bond hydrolysis has been elusive. Here we used in vitro selection to identify DNA catalysts that hydrolyze ester linkages as well as DNA catalysts that hydrolyze aromatic amides, for which the leaving group is an aniline moiety. The aromatic amide-hydrolyzing deoxyribozymes were examined using linear free energy relationship analysis. The hydrolysis reaction is unaffec...

  10. Analytical applications of resins containing amide and polyamine functional groups

    Orf, G. M.

    1977-12-01

    A dibutyl amide resin is used for the separation of uranium(VI), thorium(IV), and zirconium(IV) from each other and several other metal ions. Uranium(VI) and thorium(IV) are determined in the presence of large excesses of foreign metal ions and anions. A practical application of the amide resin is studied by determining uranium in low grade uranium ores. The amide resin is also used for the selective concentration of gold(III) from sea water.

  11. Structural Insights into an Oxalate-producing Serine Hydrolase with an Unusual Oxyanion Hole and Additional Lyase Activity.

    Oh, Juntaek; Hwang, Ingyu; Rhee, Sangkee

    2016-07-15

    In Burkholderia species, the production of oxalate, an acidic molecule, is a key event for bacterial growth in the stationary phase. Oxalate plays a central role in maintaining environmental pH, which counteracts inevitable population-collapsing alkaline toxicity in amino acid-based culture medium. In the phytopathogen Burkholderia glumae, two enzymes are responsible for oxalate production. First, the enzyme oxalate biosynthetic component A (ObcA) catalyzes the formation of a tetrahedral C6-CoA adduct from the substrates acetyl-CoA and oxaloacetate. Then the ObcB enzyme liberates three products from the C6-CoA adduct: oxalate, acetoacetate, and CoA. Interestingly, these two stepwise reactions are catalyzed by a single bifunctional enzyme, Obc1, from Burkholderia thailandensis and Burkholderia pseudomallei Obc1 has an ObcA-like N-terminal domain and shows ObcB activity in its C-terminal domain despite no sequence homology with ObcB. We report the crystal structure of Obc1 in its apo and glycerol-bound form at 2.5 Å and 2.8 Å resolution, respectively. The Obc1 N-terminal domain is essentially identical both in structure and function to that of ObcA. Its C-terminal domain has an α/β hydrolase fold that has a catalytic triad for oxalate production and a novel oxyanion hole distinct from the canonical HGGG motif in other α/β hydrolases. Functional analyses through mutagenesis studies suggested that His-934 is an additional catalytic acid/base for its lyase activity and liberates two additional products, acetoacetate and CoA. These results provide structural and functional insights into bacterial oxalogenesis and an example of divergent evolution of the α/β hydrolase fold, which has both hydrolase and lyase activity. PMID:27226606

  12. The influence of ferric (III citrate on ATP-hydrolases of Desulfuromonas acetoxidans ІМV В-7384

    O. Maslovska

    2013-02-01

    peroxidation products in bacterial cells confirms free radical mechanism of oxidation of polyunsaturated fatty acids. Thus, for fulfiling complete analyses of cell response against oxidative stress it was reasonable to investigate the influence of ferric (III citrate on specific ATP-hydrolase activity, Na+, K+-ATP-hydrolase activity and Mg2+-ATP-hydrolase activity of D. acetoxidans ІМV В-7384. Bacteria were cultivated in the modified Postgaite C medium during four days under the anaerobic conditions and temperature +27°С with addition from 10 to 20 mM of ferric (III citrate into the growth medium. Control samples didn’t contain investigated metal salt. Chosen concentrations of metal salt caused inhibition of bacterial growth by 20–50%. Activities of ATP-hydrolases were investigated as described. It was shown, that specific ATP-hydrolase activity of D. acetoxidans ІМV В-7384 is changing in dependance on duration of ferric (III citrate exposure and concentration of the metal salt. Addition of the ferric (III citrate in relatively low concentrations (10–12 mM causes increasing of specific ATP-hydrolase activity of D. acetoxidans IMV B-7384 in comparison with control. Activity of investigated enzymes was inhibited under the increasing of metal salt concentration in bacterial growth medium. Increase of duration of D. acetoxidans IMV B-7384 cultivation causes decrease of ATP-hydrolase activity. Addition of ferric (III citrate causes simultaneous increasing of Na+, K+-ATP-hydrolase activity and inhibition of Mg2+-ATP-hydrolase activity during four days of bacterial cultivation.

  13. Mutagenesis and carcinogenesis caused by the oxidation of nucleic acids.

    Nakabeppu, Yusaku; Sakumi, Kunihiko; Sakamoto, Katsumi; Tsuchimoto, Daisuke; Tsuzuki, Teruhisa; Nakatsu, Yoshimichi

    2006-01-01

    KEYWORDS CLASSIFICATION: adverse effects;Animals;chemistry;deficiency;DNA Damage;DNA Glycosylases;DNA Repair;DNA Repair Enzymes;Enzymes;genetics;Genomics;Guanine;Hydrolases;Intestinal Neoplasms;Japan;Liver Neoplasms;metabolism;mechanisms of carcinogenesis;Mice;Mutagenesis;Mutation;Neoplasms;Nucleic Acids;Oxidation-Reduction;Oxidative Stress;Phosphoric Monoester Hydrolases;Skin Neoplasms;Ultraviolet Rays.

  14. Copper-catalyzed oxidative amidation of aldehydes with amine salts: synthesis of primary, secondary, and tertiary amides.

    Ghosh, Subhash Chandra; Ngiam, Joyce S Y; Seayad, Abdul M; Tuan, Dang Thanh; Chai, Christina L L; Chen, Anqi

    2012-09-21

    A practical method for the amidation of aldehydes with economic ammonium chloride or amine hydrochloride salts has been developed for the synthesis of a wide variety of amides by using inexpensive copper sulfate or copper(I) oxide as a catalyst and aqueous tert-butyl hydroperoxide as an oxidant. This amidation reaction is operationally straightforward and provides primary, secondary, and tertiary amides in good to excellent yields for most cases utilizing inexpensive and readily available reagents under mild conditions. In situ formation of amine salts from free amines extends the substrate scope of the reaction. Chiral amides are also synthesized from their corresponding chiral amines without detectable racemization. The practicality of this amide formation reaction has been demonstrated in an efficient synthesis of the antiarrhythmic drug N-acetylprocainamide. PMID:22894712

  15. Endogenous Auxin Profile in the Christmas Rose (Helleborus niger L.) Flower and Fruit: Free and Amide Conjugated IAA

    Brcko, A.; Pěnčík, Aleš; Magnus, V.; Prebeg, T.; Mlinaric, S.; Antunovic, J.; Lepeduš, H.; Cesar, V.; Strnad, Miroslav; Rolčík, Jakub; Salopek-Sondi, B.

    2012-01-01

    Roč. 31, č. 1 (2012), s. 63-78. ISSN 0721-7595 R&D Projects: GA AV ČR KAN200380801 Keywords : Auxin * Indole-3-acetic acid * Amide conjugates * Christmas rose * Helleborus niger L. * Flower and fruit development * Perianth greening * Peduncle elongation * Vascular system Subject RIV: EF - Botanics Impact factor: 1.990, year: 2012

  16. α/β Hydrolase Domain-containing 6 (ABHD6) Degrades the Late Endosomal/Lysosomal Lipid Bis(monoacylglycero)phosphate.

    Pribasnig, Maria A; Mrak, Irina; Grabner, Gernot F; Taschler, Ulrike; Knittelfelder, Oskar; Scherz, Barbara; Eichmann, Thomas O; Heier, Christoph; Grumet, Lukas; Kowaliuk, Jakob; Romauch, Matthias; Holler, Stefan; Anderl, Felix; Wolinski, Heimo; Lass, Achim; Breinbauer, Rolf; Marsche, Gunther; Brown, J Mark; Zimmermann, Robert

    2015-12-11

    α/β Hydrolase domain-containing 6 (ABHD6) can act as monoacylglycerol hydrolase and is believed to play a role in endocannabinoid signaling as well as in the pathogenesis of obesity and liver steatosis. However, the mechanistic link between gene function and disease is incompletely understood. Here we aimed to further characterize the role of ABHD6 in lipid metabolism. We show that mouse and human ABHD6 degrade bis(monoacylglycero)phosphate (BMP) with high specific activity. BMP, also known as lysobisphosphatidic acid, is enriched in late endosomes/lysosomes, where it plays a key role in the formation of intraluminal vesicles and in lipid sorting. Up to now, little has been known about the catabolism of this lipid. Our data demonstrate that ABHD6 is responsible for ∼ 90% of the BMP hydrolase activity detected in the liver and that knockdown of ABHD6 increases hepatic BMP levels. Tissue fractionation and live-cell imaging experiments revealed that ABHD6 co-localizes with late endosomes/lysosomes. The enzyme is active at cytosolic pH and lacks acid hydrolase activity, implying that it degrades BMP exported from acidic organelles or de novo-formed BMP. In conclusion, our data suggest that ABHD6 controls BMP catabolism and is therefore part of the late endosomal/lysosomal lipid-sorting machinery. PMID:26491015

  17. α/β Hydrolase Domain-containing 6 (ABHD6) Degrades the Late Endosomal/Lysosomal Lipid Bis(monoacylglycero)phosphate*

    Pribasnig, Maria A.; Mrak, Irina; Grabner, Gernot F.; Taschler, Ulrike; Knittelfelder, Oskar; Scherz, Barbara; Eichmann, Thomas O.; Heier, Christoph; Grumet, Lukas; Kowaliuk, Jakob; Romauch, Matthias; Holler, Stefan; Anderl, Felix; Wolinski, Heimo; Lass, Achim; Breinbauer, Rolf; Marsche, Gunther; Brown, J. Mark; Zimmermann, Robert

    2015-01-01

    α/β Hydrolase domain-containing 6 (ABHD6) can act as monoacylglycerol hydrolase and is believed to play a role in endocannabinoid signaling as well as in the pathogenesis of obesity and liver steatosis. However, the mechanistic link between gene function and disease is incompletely understood. Here we aimed to further characterize the role of ABHD6 in lipid metabolism. We show that mouse and human ABHD6 degrade bis(monoacylglycero)phosphate (BMP) with high specific activity. BMP, also known as lysobisphosphatidic acid, is enriched in late endosomes/lysosomes, where it plays a key role in the formation of intraluminal vesicles and in lipid sorting. Up to now, little has been known about the catabolism of this lipid. Our data demonstrate that ABHD6 is responsible for ∼90% of the BMP hydrolase activity detected in the liver and that knockdown of ABHD6 increases hepatic BMP levels. Tissue fractionation and live-cell imaging experiments revealed that ABHD6 co-localizes with late endosomes/lysosomes. The enzyme is active at cytosolic pH and lacks acid hydrolase activity, implying that it degrades BMP exported from acidic organelles or de novo-formed BMP. In conclusion, our data suggest that ABHD6 controls BMP catabolism and is therefore part of the late endosomal/lysosomal lipid-sorting machinery. PMID:26491015

  18. Conformational diversity and enantioconvergence in potato epoxide hydrolase 1.

    Bauer, P; Carlsson, Å Janfalk; Amrein, B A; Dobritzsch, D; Widersten, M; Kamerlin, S C L

    2016-06-28

    Potato epoxide hydrolase 1 (StEH1) is a biocatalytically important enzyme that exhibits rich enantio- and regioselectivity in the hydrolysis of chiral epoxide substrates. In particular, StEH1 has been demonstrated to enantioconvergently hydrolyze racemic mixes of styrene oxide (SO) to yield (R)-1-phenylethanediol. This work combines computational, crystallographic and biochemical analyses to understand both the origins of the enantioconvergent behavior of the wild-type enzyme, as well as shifts in activities and substrate binding preferences in an engineered StEH1 variant, R-C1B1, which contains four active site substitutions (W106L, L109Y, V141K and I155V). Our calculations are able to reproduce both the enantio- and regioselectivities of StEH1, and demonstrate a clear link between different substrate binding modes and the corresponding selectivity, with the preferred binding modes being shifted between the wild-type enzyme and the R-C1B1 variant. Additionally, we demonstrate that the observed changes in selectivity and the corresponding enantioconvergent behavior are due to a combination of steric and electrostatic effects that modulate both the accessibility of the different carbon atoms to the nucleophilic side chain of D105, as well as the interactions between the substrate and protein amino acid side chains and active site water molecules. Being able to computationally predict such subtle effects for different substrate enantiomers, as well as to understand their origin and how they are affected by mutations, is an important advance towards the computational design of improved biocatalysts for enantioselective synthesis. PMID:27049844

  19. Structures of Plutonium(IV) and Uranium(VI) with N,N-Dialkyl Amides from Crystallography, X-ray Absorption Spectra, and Theoretical Calculations.

    Acher, Eléonor; Hacene Cherkaski, Yanis; Dumas, Thomas; Tamain, Christelle; Guillaumont, Dominique; Boubals, Nathalie; Javierre, Guilhem; Hennig, Christoph; Solari, Pier Lorenzo; Charbonnel, Marie-Christine

    2016-06-01

    The structures of plutonium(IV) and uranium(VI) ions with a series of N,N-dialkyl amides ligands with linear and branched alkyl chains were elucidated from single-crystal X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), and theoretical calculations. In the field of nuclear fuel reprocessing, N,N-dialkyl amides are alternative organic ligands to achieve the separation of uranium(VI) and plutonium(IV) from highly concentrated nitric acid solution. EXAFS analysis combined with XRD shows that the coordination structure of U(VI) is identical in the solution and in the solid state and is independent of the alkyl chain: two amide ligands and four bidentate nitrate ions coordinate the uranyl ion. With linear alkyl chain amides, Pu(IV) also adopt identical structures in the solid state and in solution with two amides and four bidentate nitrate ions. With branched alkyl chain amides, the coordination structure of Pu(IV) was more difficult to establish unambiguously from EXAFS. Density functional theory (DFT) calculations were consequently performed on a series of structures with different coordination modes. Structural parameters and Debye-Waller factors derived from the DFT calculations were used to compute EXAFS spectra without using fitting parameters. By using this methodology, it was possible to show that the branched alkyl chain amides form partly outer-sphere complexes with protonated ligands hydrogen bonded to nitrate ions. PMID:27171842

  20. Amide as an efficient ligand in the palladium-catalyzed Suzuki coupling reaction in water/ethanol under aerobic conditions

    Hai Yang Liu; Kun Wang; Hai Yan Fu; Mao Lin Yuan; Hua Chen; Rui Xiang Li

    2011-01-01

    Amide, which is derived from proline and is inexpensive and air-stable, has been synthesized and characterized by 1H NMR,13C NMR, and MS. It was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling reaction. In the Pd/amide catalytic system, aryl bromides can be coupled with phenylboronic acid in ethanol/water (1:2;v/v) in excellent yields even with a low Pd loading of 0.01 mol%. Moreover, the scope of the reaction is broad, and a wide variety of functional groups are tolerant.

  1. Expression, purification, and buffer solubility optimization of the putative human peptidyl-tRNA hydrolase PTRHD1.

    Burks, Geordan L; McFeeters, Hana; McFeeters, Robert L

    2016-10-01

    Performing the essential function of recycling peptidyl-tRNAs, peptidyl-tRNA hydrolases are ubiquitous in all domains of life. The multicomponent eukaryotic Pth system differs greatly from the bacterial system composed predominantly of a single Pth1 enzyme. While bacterial Pth1s are structurally well characterized and promising new targets for antibiotic development, eukaryotic Pths are largely understudied. From amino acid sequence alignment and secondary structure predictions, the human gene product PTRHD1 was classified as a eukaryotic Pth. Herein, we report cloning, recombinant bacterial expression, and weak binding to peptidyl-tRNA for PTRHD1. Additionally, we report binding to tRNA but absence of peptidyl-tRNA hydrolase activity. Thus, PTRHD1 is not a Pth and the functional consequence of nucleotide binding remains undefined. PMID:27235175

  2. Diversity and biocatalytic potential of epoxide hydrolases identified by genome analysis

    van der Loo, B; Kingma, J.; Arand, M; Wubbolts, Marcel; Janssen, D B

    2006-01-01

    Epoxide hydrolases play an important role in the biodegradation of organic compounds and are potentially useful in enantioselective biocatalysis. An analysis of various genomic databases revealed that about 20% of sequenced organisms contain one or more putative epoxide hydrolase genes. They were found in all domains of life, and many fungi and actinobacteria contain several putative epoxide hydrolase-encoding genes. Multiple sequence alignments of epoxide hydrolases with other known and puta...

  3. Development of organophosphate hydrolase activity in a bacterial homolog of human cholinesterase

    Legler, Patricia; Boisvert, Susanne; Compton, Jaimee; Millard, Charles

    2014-07-01

    We applied a combination of rational design and directed evolution (DE) to Bacillus subtilis p-nitrobenzyl esterase (pNBE) with the goal of enhancing organophosphorus acid anhydride hydrolase (OPAAH) activity. DE started with a designed variant, pNBE A107H, carrying a histidine homologous with human butyrylcholinesterase G117H to find complementary mutations that further enhance its OPAAH activity. Five sites were selected (G105, G106, A107, A190, and A400) within a 6.7 Å radius of the nucleophilic serine O?. All 95 variants were screened for esterase activity with a set of five substrates: pNP-acetate, pNP-butyrate, acetylthiocholine, butyrylthiocholine, or benzoylthiocholine. A microscale assay for OPAAH activity was developed for screening DE libraries. Reductions in esterase activity were generally concomitant with enhancements in OPAAH activity. One variant, A107K, showed an unexpected 7-fold increase in its kcat/Km for benzoylthiocholine, demonstrating that it is also possible to enhance the cholinesterase activity of pNBE. Moreover, DE resulted in at least three variants with modestly enhanced OPAAH activity compared to wild type pNBE. A107H/A190C showed a 50-fold increase in paraoxonase activity and underwent a slow time- and temperature-dependent change affecting the hydrolysis of OPAA and ester substrates. Structural analysis suggests that pNBE may represent a precursor leading to human cholinesterase and carboxylesterase 1 through extension of two vestigial specificity loops; a preliminary attempt to transfer the Ω-loop of BChE into pNBE is described. pNBE was tested as a surrogate scaffold for mammalian esterases. Unlike butyrylcholinesterase and pNBE, introducing a G143H mutation (equivalent to G117H) did not confer detectable OP hydrolase activity on human carboxylesterase 1. We discuss the importance of the oxyanion-hole residues for enhancing the OPAAH activity of selected serine hydrolases.

  4. Development of organophosphate hydrolase activity in a bacterial homolog of human cholinesterase

    Patricia Marie Legler

    2014-07-01

    Full Text Available We applied a combination of rational design and directed evolution (DE to Bacillus subtilis p-nitrobenzyl esterase (pNBE with the goal of enhancing organophosphorus acid anhydride hydrolase (OPAAH activity. DE started with a designed variant, pNBE A107H, carrying a histidine homologous with human butyrylcholinesterase G117H to find complementary mutations that further enhance its OPAAH activity. Five sites were selected (G105, G106, A107, A190, and A400 within a 6.7 Å radius of the nucleophilic serine O. All 95 variants were screened for esterase activity with a set of five substrates: pNP-acetate, pNP-butyrate, acetylthiocholine, butyrylthiocholine, or benzoylthiocholine. A microscale assay for OPAAH activity was developed for screening DE libraries. Reductions in esterase activity were generally concomitant with enhancements in OPAAH activity. One variant, A107K, showed an unexpected 7-fold increase in its kcat/Km for benzoylthiocholine, demonstrating that it is also possible to enhance the cholinesterase activity of pNBE. Moreover, DE resulted in at least three variants with modestly enhanced OPAAH activity compared to wild type pNBE. A107H/A190C showed a 50-fold increase in paraoxonase activity and underwent a slow time- and temperature-dependent change affecting the hydrolysis of OPAA and ester substrates. Structural analysis suggests that pNBE may represent a precursor leading to human cholinesterase and carboxylesterase 1 through extension of two vestigial specificity loops; a preliminary attempt to transfer the Ω-loop of BChE into pNBE is described. pNBE was tested as a surrogate scaffold for mammalian esterases. Unlike butyrylcholinesterase and pNBE, introducing a G143H mutation (equivalent to G117H did not confer detectable OP hydrolase activity on human carboxylesterase 1. We discuss the importance of the oxyanion-hole residues for enhancing the OPAAH activity of selected serine hydrolases.

  5. Dysregulation of soluble epoxide hydrolase and lipidomic profiles in anorexia nervosa.

    Shih, P B; Yang, J; Morisseau, C; German, J B; Zeeland, A A Scott-Van; Armando, A M; Quehenberger, O; Bergen, A W; Magistretti, P; Berrettini, W; Halmi, K A; Schork, N; Hammock, B D; Kaye, W

    2016-04-01

    Individuals with anorexia nervosa (AN) restrict eating and become emaciated. They tend to have an aversion to foods rich in fat. Because epoxide hydrolase 2 (EPHX2) was identified as a novel AN susceptibility gene, and because its protein product, soluble epoxide hydrolase (sEH), converts bioactive epoxides of polyunsaturated fatty acid (PUFA) to the corresponding diols, lipidomic and metabolomic targets of EPHX2 were assessed to evaluate the biological functions of EPHX2 and their role in AN. Epoxide substrates of sEH and associated oxylipins were measured in ill AN, recovered AN and gender- and race-matched controls. PUFA and oxylipin markers were tested as potential biomarkers for AN. Oxylipin ratios were calculated as proxy markers of in vivo sEH activity. Several free- and total PUFAs were associated with AN diagnosis and with AN recovery. AN displayed elevated n-3 PUFAs and may differ from controls in PUFA elongation and desaturation processes. Cytochrome P450 pathway oxylipins from arachidonic acid, linoleic acid, alpha-linolenic acid and docosahexaenoic acid PUFAs are associated with AN diagnosis. The diol:epoxide ratios suggest the sEH activity is higher in AN compared with controls. Multivariate analysis illustrates normalization of lipidomic profiles in recovered ANs. EPHX2 influences AN risk through in vivo interaction with dietary PUFAs. PUFA composition and concentrations as well as sEH activity may contribute to the pathogenesis and prognosis of AN. Our data support the involvement of EPHX2-associated lipidomic and oxylipin dysregulations in AN, and reveal their potential as biomarkers to assess responsiveness to future intervention or treatment. PMID:25824304

  6. Human Lung Hydrolases Delineate Mycobacterium tuberculosis–Macrophage Interactions and the Capacity To Control Infection

    Arcos, Jesus; Sasindran, Smitha J.; Fujiwara, Nagatoshi; Turner, Joanne; Schlesinger, Larry S; Torrelles, Jordi B.

    2011-01-01

    Pulmonary surfactant contains homeostatic and antimicrobial hydrolases. When Mycobacterium tuberculosis is initially deposited in the terminal bronchioles and alveoli, as well as following release from lysed macrophages, bacilli are in intimate contact with these lung surfactant hydrolases. We identified and measured several hydrolases in human alveolar lining fluid and lung tissue that, at their physiological concentrations, dramatically modified the M. tuberculosis cell envelope. Independen...

  7. A Substrate-Assisted Mechanism of Nucleophile Activation in a Ser-His-Asp Containing C-C Bond Hydrolase

    Ruzzini, Antonio C.; Bhowmik, Shiva; Ghosh, Subhangi; Yam, Katherine C.; Bolin, Jeffrey T.; Eltis, Lindsay D. [Purdue; (UBC)

    2013-11-12

    The meta-cleavage product (MCP) hydrolases utilize a Ser–His–Asp triad to hydrolyze a carbon–carbon bond. Hydrolysis of the MCP substrate has been proposed to proceed via an enol-to-keto tautomerization followed by a nucleophilic mechanism of catalysis. Ketonization involves an intermediate, ESred, which possesses a remarkable bathochromically shifted absorption spectrum. We investigated the catalytic mechanism of the MCP hydrolases using DxnB2 from Sphingomonas wittichii RW1. Pre-steady-state kinetic and LC ESI/MS evaluation of the DxnB2-mediated hydrolysis of 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid to 2-hydroxy-2,4-pentadienoic acid and benzoate support a nucleophilic mechanism catalysis. In DxnB2, the rate of ESred decay and product formation showed a solvent kinetic isotope effect of 2.5, indicating that a proton transfer reaction, assigned here to substrate ketonization, limits the rate of acylation. For a series of substituted MCPs, this rate was linearly dependent on MCP pKa2nuc ~ 1). Structural characterization of DxnB2 S105A:MCP complexes revealed that the catalytic histidine is displaced upon substrate-binding. The results provide evidence for enzyme-catalyzed ketonization in which the catalytic His–Asp pair does not play an essential role. The data further suggest that ESred represents a dianionic intermediate that acts as a general base to activate the serine nucleophile. This substrate-assisted mechanism of nucleophilic catalysis distinguishes MCP hydrolases from other serine hydrolases.

  8. Proximate and qualitative analysis of different parts of Piper sarmentosum, and quantification of total amides in various extracts

    K Hussain

    2009-01-01

    Full Text Available Present study aimed to analyze crude powders and extracts of different parts of Piper sarmentosum for proximate, qualitative and quantitative studies to prepare standardized botanical drugs from the plant. Unlike synthetic drugs, standardization of botanical drugs is always challenging for natural product researchers due to inadequacy and unavailability of standards and methods. Standardization of botanical drugs is not just an analytical process which ends with the detection of few constituents rather it embodies a set of analytical, biochemical and biological protocols. Keeping analytical protocols in view, crude powders were analyzed for the content of moisture, total ash, acid insoluble ash, sulphated ash and soluble extractives in water and methanol. These physicochemical properties were found within specified limits. Comparison of Fourier Transform Infrared (FTIR fingerprints of crude powders of different parts indicated the difference of constituents. Similarly, comparison of ultra violet (UV profiles of extracts of all the parts exhibited discrimination. Qualitative analysis of aqueous and ethanol extracts by high performance thin layer chromatography (HPTLC indicated the presence of amides in ethanol extracts of all parts of the plant. Quantitative analysis of extracts indicated that total amide content was significantly higher by colorimetry as compared to UV spectrophotometry. The distribution of amides in different parts was in the order fruit > root > leaf > stem (P=0.000. It is concluded from the study that amide content varies in different parts of the plant and ethanol is a better solvent for their extraction. Additionally, colorimetric method exhibits high content of amides.

  9. Synthesis and quantitation of six phenolic amides in Amaranthus spp.

    Pedersen, Hans A; Steffensen, Stine K; Christophersen, Carsten; Mortensen, Anne G; Jørgensen, Lise N; Niveyro, Selene; de Troiani, Rosa M; Rodríguez-Enríquez, Ricardo José; Barba-de la Rosa, Ana Paulina; Fomsgaard, Inge S

    2010-05-26

    Cinnamoylphenethylamines are phenolic amides in which cinnamic acid provides the acid moiety and phenethylamine the amine moiety. Single ion monitoring (SIM) in LC-MS was performed on amaranth leaf extracts. Masses corresponding to sets of regioisomers, including previously reported compounds, were examined. Six peaks were detected and their corresponding standards synthesized for a quantitative LC-MS/MS investigation of cinnamoylphenethylamines in amaranth. Four cinnamoylphenethylamines (caffeoyltyramine, feruloyldopamine, sinapoyltyramine, and p-coumaroyltyramine) are reported in the Amaranthaceae for the first time; also, one rare compound, feruloyl-4-O-methyldopamine, appeared to be quite common in the genus Amaranthus. Feruloyldopamine showed moderate antifungal activity toward an isolate of Fusarium culmorum. Our LC-MS approach, in conjunction with the straightforward synthesis, provides a simple, reliable way of quantitatively investigating cinnamoylphenethylamines in plants. Concentrations of cinnamoylphenethylamines vary widely: feruloyltyramine was present in quantities of 5.26 to 114.31 microg/g and feruloyldopamine in quantities of 0.16 to 10.27 microg/g, depending on the plant sample. PMID:20438062

  10. Oxidative activation of dihydropyridine amides to reactive acyl donors

    Funder, Erik Daa; Trads, Julie Brender; Gothelf, Kurt Vesterager

    2015-01-01

    Amides of 1,4-dihydropyridine (DHP) are activated by oxidation for acyl transfer to amines, alcohols and thiols. In the reduced form the DHP amide is stable towards reaction with amines at room temperature. However, upon oxidation with DDQ the acyl donor is activated via a proposed pyridinium...

  11. Temperature-Dependence of the Amide-I Frequency Map for Peptides and Proteins

    Chen Han; Jian-ping Wang

    2011-01-01

    In our recent work [Phys.Chem.Chem.Phys.11,9149 (2009)],a molecular-mechanics force field-based amide-I vibration frequency map (MM-map) for peptides and proteins was constructed.In this work,the temperature dependence of the MM-map is examined based on high-temperature molecular dynamics simulations and infrared (IR) experiments.It is shown that the 298-K map works for up to 500-K molecular dynamics trajectories,which reasonably reproduces the 88 ℃ experimental IR results.Linear IR spectra are also simulated for two tripeptides containing natural and unnatural amino acid residues,and the results are in reasonable agreement with experiment.The results suggest the MM-map can be used to obtain the temperature-dependent amide-I local mode frequencies and their distributions for peptide oligomers,which is useful in particular for understanding the IR signatures of the thermally unfolded species.

  12. AIG1 and ADTRP are atypical integral membrane hydrolases that degrade bioactive FAHFAs.

    Parsons, William H; Kolar, Matthew J; Kamat, Siddhesh S; Iii, Armand B Cognetta; Hulce, Jonathan J; Saez, Enrique; Kahn, Barbara B; Saghatelian, Alan; Cravatt, Benjamin F

    2016-05-01

    Enzyme classes may contain outlier members that share mechanistic, but not sequence or structural, relatedness with more common representatives. The functional annotation of such exceptional proteins can be challenging. Here, we use activity-based profiling to discover that the poorly characterized multipass transmembrane proteins AIG1 and ADTRP are atypical hydrolytic enzymes that depend on conserved threonine and histidine residues for catalysis. Both AIG1 and ADTRP hydrolyze bioactive fatty acid esters of hydroxy fatty acids (FAHFAs) but not other major classes of lipids. We identify multiple cell-active, covalent inhibitors of AIG1 and show that these agents block FAHFA hydrolysis in mammalian cells. These results indicate that AIG1 and ADTRP are founding members of an evolutionarily conserved class of transmembrane threonine hydrolases involved in bioactive lipid metabolism. More generally, our findings demonstrate how chemical proteomics can excavate potential cases of convergent or parallel protein evolution that defy conventional sequence- and structure-based predictions. PMID:27018888

  13. Cytotoxic Amides from Fruits of Kawakawa, Macropiper excelsum.

    Lei, Jeremy; Burgess, Elaine J; Richardson, Alistair T B; Hawkins, Bill C; Baird, Sarah K; Smallfield, Bruce M; van Klink, John W; Perry, Nigel B

    2015-08-01

    Cytotoxic amides have been isolated from the fruits of the endemic New Zealand medicinal plant kawakawa, Macropiper excelsum (Piperaceae). The main amide was piperchabamide A and this is the first report of this rare compound outside the genus Piper. Eleven other amides were purified including two new compounds with the unusual 3,4-dihydro-1(2H)-pyridinyl group. The new compounds were fully characterized by 2D NMR spectroscopy, which showed a slow exchange between two rotamers about the amide bond, and they were chemically synthesized. In view of the antitumor activity of the related piperlongumine, all of these amides plus four synthetic analogs were tested for cytotoxicity. The most active was the piperine homolog piperdardine, with an IC50 of 14 µM against HT 29 colon cancer cells. PMID:26039266

  14. Phenotypic and genotypic characterization of peptidoglycan hydrolases of Lactobacillus sakei

    Afef Najjari

    2016-01-01

    Full Text Available Lactobacillus sakei, a lactic acid bacterium naturally found in fresh meat and sea products, is considered to be one of the most important bacterial species involved in meat fermentation and bio-preservation. Several enzymes of Lb. sakei species contributing to microbial safeguarding and organoleptic properties of fermented-meat were studied. However, the specific autolytic mechanisms and associated enzymes involved in Lb. sakei are not well understood. The autolytic phenotype of 22 Lb. sakei strains isolated from Tunisian meat and seafood products was evaluated under starvation conditions, at pH 6.5 and 8.5, and in the presence of different carbon sources. A higher autolytic rate was observed when cells were grown in the presence of glucose and incubated at pH 6.5. Almost all strains showed high resistance to mutanolysin, indicating a minor role of muramidases in Lb. sakei cell lysis. Using Micrococcus lysodeikticus cells as a substrate in activity gels zymogram, peptidoglycan hydrolase (PGH patterns for all strains was characterized by two lytic bands of ∼80 (B1 and ∼70 kDa (B2, except for strain BMG.167 which harbored two activity signals at a lower MW. Lytic activity was retained in high salt and in acid/basic conditions and was active toward cells of Lb. sakei, Listeria monocytogenes, Listeria ivanovii and Listeria innocua. Analysis of five putative PGH genes found in the Lb. sakei 23 K model strain genome, indicated that one gene, lsa1437, could encode a PGH (N-acetylmuramoyl-L-alanine amidase containing B1 and B2 as isoforms. According to this hypothesis, strain BMG.167 showed an allelic version of lsa1437 gene deleted of one of the five LysM domains, leading to a reduction in the MW of lytic bands and the high autolytic rate of this strain. Characterization of autolytic phenotype of Lb. sakei should expand the knowledge of their role in fermentation processes where they represent the dominant species.

  15. Phenotypic and genotypic characterization of peptidoglycan hydrolases of Lactobacillus sakei.

    Najjari, Afef; Amairi, Houda; Chaillou, Stéphane; Mora, Diego; Boudabous, Abdellatif; Zagorec, Monique; Ouzari, Hadda

    2016-01-01

    Lactobacillus sakei, a lactic acid bacterium naturally found in fresh meat and sea products, is considered to be one of the most important bacterial species involved in meat fermentation and bio-preservation. Several enzymes of Lb. sakei species contributing to microbial safeguarding and organoleptic properties of fermented-meat were studied. However, the specific autolytic mechanisms and associated enzymes involved in Lb. sakei are not well understood. The autolytic phenotype of 22 Lb. sakei strains isolated from Tunisian meat and seafood products was evaluated under starvation conditions, at pH 6.5 and 8.5, and in the presence of different carbon sources. A higher autolytic rate was observed when cells were grown in the presence of glucose and incubated at pH 6.5. Almost all strains showed high resistance to mutanolysin, indicating a minor role of muramidases in Lb. sakei cell lysis. Using Micrococcus lysodeikticus cells as a substrate in activity gels zymogram, peptidoglycan hydrolase (PGH) patterns for all strains was characterized by two lytic bands of ∼80 (B1) and ∼70 kDa (B2), except for strain BMG.167 which harbored two activity signals at a lower MW. Lytic activity was retained in high salt and in acid/basic conditions and was active toward cells of Lb. sakei, Listeria monocytogenes, Listeria ivanovii and Listeria innocua. Analysis of five putative PGH genes found in the Lb. sakei 23 K model strain genome, indicated that one gene, lsa1437, could encode a PGH (N-acetylmuramoyl-L-alanine amidase) containing B1 and B2 as isoforms. According to this hypothesis, strain BMG.167 showed an allelic version of lsa1437 gene deleted of one of the five LysM domains, leading to a reduction in the MW of lytic bands and the high autolytic rate of this strain. Characterization of autolytic phenotype of Lb. sakei should expand the knowledge of their role in fermentation processes where they represent the dominant species. PMID:26843981

  16. Vaccenic acid suppresses intestinal inflammation by increasing anandamide and related N-acylethanolamines in the JCR:LA-cp rat.

    Jacome-Sosa, Miriam; Vacca, Claudia; Mangat, Rabban; Diane, Abdoulaye; Nelson, Randy C; Reaney, Martin J; Shen, Jianheng; Curtis, Jonathan M; Vine, Donna F; Field, Catherine J; Igarashi, Miki; Piomelli, Daniele; Banni, Sebastiano; Proctor, Spencer D

    2016-04-01

    Vaccenic acid (VA), the predominant ruminant-derivedtransfat in the food chain, ameliorates hyperlipidemia, yet mechanisms remain elusive. We investigated whether VA could influence tissue endocannabinoids (ECs) by altering the availability of their biosynthetic precursor, arachidonic acid (AA), in membrane phospholipids (PLs). JCR:LA-cprats were assigned to a control diet with or without VA (1% w/w),cis-9,trans-11 conjugated linoleic acid (CLA) (1% w/w) or VA+CLA (1% + 0.5% w/w) for 8 weeks. VA reduced the EC, 2-arachidonoylglycerol (2-AG), in the liver and visceral adipose tissue (VAT) relative to control diet (PCLA on 2-AG relative to VA alone (P> 0.05). Interestingly, VA increased jejunal concentrations of anandamide and those of the noncannabinoid signaling molecules, oleoylethanolamide and palmitoylethanolamide, relative to control diet (P< 0.05). This was consistent with a lower jejunal protein abundance (but not activity) of their degrading enzyme, fatty acid amide hydrolase, as well as the mRNA expression of TNFα and interleukin 1β (P< 0.05). The ability of VA to reduce 2-AG in the liver and VAT provides a potential mechanistic explanation to alleviate ectopic lipid accumulation. The opposing regulation of ECs and other noncannabinoid lipid signaling molecules by VA suggests an activation of benefit via the EC system in the intestine. PMID:26891736

  17. Insights into Substrate Specificity of NlpC/P60 Cell Wall Hydrolases Containing Bacterial SH3 Domains

    Xu, Qingping; Mengin-Lecreulx, Dominique; Liu, Xueqian W.; Patin, Delphine; Farr, Carol L.; Grant, Joanna C.; Chiu, Hsiu-Ju; Jaroszewski, Lukasz; Knuth, Mark W.; Godzik, Adam; Lesley, Scott A.; Elsliger, Marc-André; Deacon, Ashley M.; Wilson, Ian A.

    2015-09-15

    ABSTRACT

    Bacterial SH3 (SH3b) domains are commonly fused with papain-like Nlp/P60 cell wall hydrolase domains. To understand how the modular architecture of SH3b and NlpC/P60 affects the activity of the catalytic domain, three putative NlpC/P60 cell wall hydrolases were biochemically and structurally characterized. These enzymes all have γ-d-Glu-A2pm (A2pm is diaminopimelic acid) cysteine amidase (ordl-endopeptidase) activities but with different substrate specificities. One enzyme is a cell wall lysin that cleaves peptidoglycan (PG), while the other two are cell wall recycling enzymes that only cleave stem peptides with an N-terminall-Ala. Their crystal structures revealed a highly conserved structure consisting of two SH3b domains and a C-terminal NlpC/P60 catalytic domain, despite very low sequence identity. Interestingly, loops from the first SH3b domain dock into the ends of the active site groove of the catalytic domain, remodel the substrate binding site, and modulate substrate specificity. Two amino acid differences at the domain interface alter the substrate binding specificity in favor of stem peptides in recycling enzymes, whereas the SH3b domain may extend the peptidoglycan binding surface in the cell wall lysins. Remarkably, the cell wall lysin can be converted into a recycling enzyme with a single mutation.

    IMPORTANCEPeptidoglycan is a meshlike polymer that envelops the bacterial plasma membrane and bestows structural integrity. Cell wall lysins and recycling enzymes are part of a set of lytic enzymes that target covalent bonds connecting the amino acid and amino sugar building blocks of the PG network. These hydrolases are involved in processes such as cell growth and division, autolysis, invasion, and PG turnover and recycling. To avoid cleavage of unintended substrates, these enzymes have very selective substrate specificities. Our biochemical and structural

  18. Monoclonal Antibodies Specific for Hippurate Hydrolase of Campylobacter jejuni

    Steele, Marina; Gyles, Carlton; Chan, Voon Loong; Odumeru, Joseph

    2002-01-01

    Eleven monoclonal antibodies raised against recombinant Campylobacter jejuni hippurate hydrolase were tested for binding to lysates from 19 C. jejuni strains, 12 other Campylobacter strains, and 21 non-Campylobacter strains. Several monoclonal antibodies bound to C. jejuni but not to other Campylobacter species and may be useful in a species-specific immunoassay.

  19. Bile salt hydrolase of Bifidobacterium longum - Biochemical and genetic characterization

    Tanaka, H; Hashiba, Honoo; Kok, Jan; Mierau, Igor

    2000-01-01

    A bile salt hydrolase (BSH) was isolated from Bifidobacterium longum SBT2928, purified, and characterized, Furthermore, we describe for the first time cloning and analysis of the gene encoding BSII (bsh) in a member of the genus Bifidobacterium. The enzyme has a native molecular weight of 125,000 to

  20. Carbocyclic pyrimidine nucleosides as inhibitors of S-adenosylhomocysteine hydrolase.

    Mosley, Sylvester L; Bakke, Brian A; Sadler, Joshua M; Sunkara, Naresh K; Dorgan, Kathleen M; Zhou, Zhaohui Sunny; Seley-Radtke, Katherine L

    2006-12-01

    The design, synthesis, and unexpected inhibitory activity against S-adenosyl-homocysteine (SAH) hydrolase (SAHase, EC 3.3.1.1) for a series of truncated carbocyclic pyrimidine nucleoside analogues is presented. Of the four nucleosides obtained, 10 was found to be active with a Ki value of 5.0 microM against SAHase. PMID:16904326

  1. Curation of characterized glycoside hydrolases of fungal origin.

    Murphy, Caitlin; Powlowski, Justin; Wu, Min; Butler, Greg; Tsang, Adrian

    2011-01-01

    Fungi produce a wide range of extracellular enzymes to break down plant cell walls, which are composed mainly of cellulose, lignin and hemicellulose. Among them are the glycoside hydrolases (GH), the largest and most diverse family of enzymes active on these substrates. To facilitate research and development of enzymes for the conversion of cell-wall polysaccharides into fermentable sugars, we have manually curated a comprehensive set of characterized fungal glycoside hydrolases. Characterized glycoside hydrolases were retrieved from protein and enzyme databases, as well as literature repositories. A total of 453 characterized glycoside hydrolases have been cataloged. They come from 131 different fungal species, most of which belong to the phylum Ascomycota. These enzymes represent 46 different GH activities and cover 44 of the 115 CAZy GH families. In addition to enzyme source and enzyme family, available biochemical properties such as temperature and pH optima, specific activity, kinetic parameters and substrate specificities were recorded. To simplify comparative studies, enzyme and species abbreviations have been standardized, Gene Ontology terms assigned and reference to supporting evidence provided. The annotated genes have been organized in a searchable, online database called mycoCLAP (Characterized Lignocellulose-Active Proteins of fungal origin). It is anticipated that this manually curated collection of biochemically characterized fungal proteins will be used to enhance functional annotation of novel GH genes. Database URL: http://mycoCLAP.fungalgenomics.ca/. PMID:21622642

  2. Properties of epoxide hydrolase from the yeast Rhodotorula glutinis

    Ariës-Kronenburg, N.A.E.

    2002-01-01

     Epoxide hydrolases are ubiquitous enzymes that can be found in nearly all living organisms. Some of the enzymes play an important role in detoxifying xenobiotic and metabolic compounds. Others are important in the growth of organisms like the juvenile hormone in some insec

  3. DEVELOPMENT OF METABOLICALLY STABLE INHIBITORS OF MAMMALIAN MICROSOMAL EPOXIDE HYDROLASE

    The microsomal epoxide hydrolase (mEH) plays a significant role in the metabolism of xenobiotics such as polyaromatic toxicants. Additionally, polymorphism studies have underlined a potential role of this enzyme in relation to a number of diseases, such as emphysema, spontaneous abortion, eclampsia ...

  4. Cloning, expression and mutation of a triazophos hydrolase gene from Burkholderia sp. SZL-1.

    Zhang, Hao; Li, Qiang; Guo, Su-Hui; Cheng, Ming-Gen; Zhao, Meng-Jun; Hong, Qing; Huang, Xing

    2016-06-01

    Triazophos is a broad-spectrum and highly effective insecticide, and the residues of triazophos have been frequently detected in the environment. A triazophos-degrading bacterium, Burkholderia sp. SZL-1, was isolated from a long-term triazophos-polluted soil. Strain SZL-1 could hydrolyze triazophos to 1-phenyl-3-hydroxy-1,2,4-triazole, which was further utilized as the carbon sources for growth. The triazophos hydrolase gene trhA, cloned from strain SZL-1, was expressed and homogenously purified using Ni-nitrilotriacetic acid affinity chromatography. TrhA is 55 kDa and displays maximum activity at 25°C, pH 8.0. This enzyme still has nearly 60% activity at the range of 15°C-50°C for 30 min. TrhA was mutated by sequential error prone PCR and screened for improved activity for triazophos degradation. One purified variant protein (Val89-Gly89) named TrhA-M1 showed up to 3-fold improvement in specific activity against triazophos, and the specificity constants of Kcat and Kcat/Km for TrhA-M1 were improved up to 2.3- and 8.28-fold, respectively, compared to the wild-type enzyme. The results in this paper provided potential material for the contaminated soil remediation and hydrolase genetic structure research. PMID:27190294

  5. Direct detection, cloning and characterization of a glucoside hydrolase from forest soil.

    Hua, Mei; Zhao, Shubo; Zhang, Lili; Liu, Dongbo; Xia, Hongmei; Li, Fan; Chen, Shan

    2015-06-01

    A glucoside hydrolase gene, egl01, was cloned from the soil DNA of Changbai Mountain forest by homologous PCR amplification. The deduced sequence of 517 amino acids included a catalytic domain of glycoside hydrolase family 5 and was homologous to a putative cellulase from Bacillus licheniformis. The recombinant enzyme, Egl01, was maximally active at pH 5 and 50 °C and it was stable at pH 3-9, 4-50 °C, and also stable in the presence of metal ions, organic solvents, surfactants and salt. Its activity was above 120 % in 2-3 M NaCl/KCl and over 70 % was retained in 1-4 M NaCl/KCl for 6d. Egl01 hydrolyzed carboxymethyl cellulose, beechwood xylan, crop stalk, laminarin, filter paper, and avicel but not pNPG, indicating its broad substrate specificity. These properties make this recombinant enzyme a promising candidate for industrial applications. PMID:25700816

  6. Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae

    The crystal structure of 5-hydroxyisourate hydrolase from K. pneumoniae and the steady-state kinetic parameters of the native enzyme as well as several mutants provide insights into the catalytic mechanism of this enzyme and the possible roles of the active-site residues. The stereospecific oxidative degradation of uric acid to (S)-allantoin has recently been demonstrated to proceed via two unstable intermediates and requires three separate enzymatic reactions. The second step of this reaction, the conversion of 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, is catalyzed by HIU hydrolase (HIUH). The high-resolution crystal structure of HIUH from the opportunistic pathogen Klebsiella pneumoniae (KpHIUH) has been determined. KpHIUH is a homotetrameric protein that, based on sequence and structural similarity, belongs to the transthyretin-related protein family. In addition, the steady-state kinetic parameters for this enzyme and four active-site mutants have been measured. These data provide valuable insight into the functional roles of the active-site residues. Based upon the structural and kinetic data, a mechanism is proposed for the KpHIUH-catalyzed reaction

  7. Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae

    French, Jarrod B.; Ealick, Steven E., E-mail: see3@cornell.edu [Cornell University, Ithaca, NY 14853-1301 (United States)

    2011-08-01

    The crystal structure of 5-hydroxyisourate hydrolase from K. pneumoniae and the steady-state kinetic parameters of the native enzyme as well as several mutants provide insights into the catalytic mechanism of this enzyme and the possible roles of the active-site residues. The stereospecific oxidative degradation of uric acid to (S)-allantoin has recently been demonstrated to proceed via two unstable intermediates and requires three separate enzymatic reactions. The second step of this reaction, the conversion of 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, is catalyzed by HIU hydrolase (HIUH). The high-resolution crystal structure of HIUH from the opportunistic pathogen Klebsiella pneumoniae (KpHIUH) has been determined. KpHIUH is a homotetrameric protein that, based on sequence and structural similarity, belongs to the transthyretin-related protein family. In addition, the steady-state kinetic parameters for this enzyme and four active-site mutants have been measured. These data provide valuable insight into the functional roles of the active-site residues. Based upon the structural and kinetic data, a mechanism is proposed for the KpHIUH-catalyzed reaction.

  8. Naturally occurring antifungal aromatic esters and amides

    During the search of antifungal natural products from terrestrial plants, a new long chained aromatic ester named grandiflorate along with spatazoate from Portulaca grandiflora and N-[2-methoxy-2-(4-methoxyphenyl) ethyl]-trans-cinnamide and aegeline from Solanum erianthum of Nigeria were isolated and tested against six fungal species. The known constituents have not been reported so far from mentioned investigated plants. Structures of the isolated compounds were elucidated with the aid of spectroscopic techniques including two dimensional NMR experiments. Among the compounds, the esters found more potent than amides against Candida albicans and Aspergillus flavus. The new compound grandiflorate gave response against all tested fungal species while aegeline was found to give lowest inhibition during this study. (author)

  9. Novel glycoside hydrolases from thermophilic fungi

    2012-01-01

    The present invention relates to isolated polypeptides having cellulolytic activity or hemicellulolytic activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of produ...

  10. Structural relationships in the lysozyme superfamily: significant evidence for glycoside hydrolase signature motifs.

    Alexandre Wohlkönig

    Full Text Available BACKGROUND: Chitin is a polysaccharide that forms the hard, outer shell of arthropods and the cell walls of fungi and some algae. Peptidoglycan is a polymer of sugars and amino acids constituting the cell walls of most bacteria. Enzymes that are able to hydrolyze these cell membrane polymers generally play important roles for protecting plants and animals against infection with insects and pathogens. A particular group of such glycoside hydrolase enzymes share some common features in their three-dimensional structure and in their molecular mechanism, forming the lysozyme superfamily. RESULTS: Besides having a similar fold, all known catalytic domains of glycoside hydrolase proteins of lysozyme superfamily (families and subfamilies GH19, GH22, GH23, GH24 and GH46 share in common two structural elements: the central helix of the all-α domain, which invariably contains the catalytic glutamate residue acting as general-acid catalyst, and a β-hairpin pointed towards the substrate binding cleft. The invariant β-hairpin structure is interestingly found to display the highest amino acid conservation in aligned sequences of a given family, thereby allowing to define signature motifs for each GH family. Most of such signature motifs are found to have promising performances for searching sequence databases. Our structural analysis further indicates that the GH motifs participate in enzymatic catalysis essentially by containing the catalytic water positioning residue of inverting mechanism. CONCLUSIONS: The seven families and subfamilies of the lysozyme superfamily all have in common a β-hairpin structure which displays a family-specific sequence motif. These GH β-hairpin motifs contain potentially important residues for the catalytic activity, thereby suggesting the participation of the GH motif to catalysis and also revealing a common catalytic scheme utilized by enzymes of the lysozyme superfamily.

  11. Biodegradable gadolinium-chelated cationic poly(urethane amide) copolymers for gene transfection and magnetic resonance imaging.

    Gao, Xiaolong; Wang, Gangmin; Shi, Ting; Shao, Zhihong; Zhao, Peng; Shi, Donglu; Ren, Jie; Lin, Chao; Wang, Peijun

    2016-08-01

    Theranostic nano-polyplexes containing gene and imaging agents hold a great promise for tumor diagnosis and therapy. In this work, we develop a group of new gadolinium (Gd)-chelated cationic poly(urethane amide)s for gene delivery and T1-weighted magnetic resonance (MR) imaging. Cationic poly(urethane amide)s (denoted as CPUAs) having multiple disulfide bonds, urethane and amide linkages were synthesized by stepwise polycondensation reaction between 1,4-bis(3-aminopropyl)piperazine and a mixture of di(4-nitrophenyl)-2, 2'-dithiodiethanocarbonate (DTDE-PNC) and diethylenetriaminepentaacetic acid (DTPA) dianhydride at varied molar ratios. Then, Gd-chelated CPUAs (denoted as GdCPUAs) were produced by chelating Gd(III) ions with DTPA residues of CPUAs. These GdCPUAs could condense gene into nanosized and positively-charged polyplexes in a physiological condition and, however, liberated gene in an intracellular reductive environment. In vitro transfection experiments revealed that the GdCPUA at a DTDE-PNC/DTPA residue molar ratio of 85/15 induced the highest transfection efficiency in different cancer cells. This efficiency was higher than that yielded with 25kDa branched polyethylenimine as a positive control. GdCPUAs and their polyplexes exhibited low cytotoxicity when an optimal transfection activity was detected. Moreover, GdCPUAs may serve as contrast agents for T1-weighted magnetic resonance imaging. The results of this work indicate that biodegradable Gd-chelated cationic poly(urethane amide) copolymers have high potential for tumor theranostics. PMID:27157741

  12. Effect of Bile Salt Hydrolase Inhibitors on a Bile Salt Hydrolase from Lactobacillus acidophilus

    Jun Lin

    2014-12-01

    Full Text Available Bile salt hydrolase (BSH, a widely distributed function of the gut microbiota, has a profound impact on host lipid metabolism and energy harvest. Recent studies suggest that BSH inhibitors are promising alternatives to antibiotic growth promoters (AGP for enhanced animal growth performance and food safety. Using a high-purity BSH from Lactobacillus salivarius strain, we have identified a panel of BSH inhibitors. However, it is still unknown if these inhibitors also effectively inhibit the function of the BSH enzymes from other bacterial species with different sequence and substrate spectrum. In this study, we performed bioinformatics analysis and determined the inhibitory effect of identified BSH inhibitors on a BSH from L. acidophilus. Although the L. acidophilus BSH is phylogenetically distant from the L. salivarius BSH, sequence analysis and structure modeling indicated the two BSH enzymes contain conserved, catalytically important amino residues and domain. His-tagged recombinant BSH from L. acidophilus was further purified and used to determine inhibitory effect of specific compounds. Previously identified BSH inhibitors also exhibited potent inhibitory effects on the L. acidophilus BSH. In conclusion, this study demonstrated that the BSH from L. salivarius is an ideal candidate for screening BSH inhibitors, the promising alternatives to AGP for enhanced feed efficiency, growth performance and profitability of food animals.

  13. Synthesis, spectroscopic and structural perspective of new ferrocenyl amides

    Etter, Martin; Nigar, Asifa; Ali, Naveed Zafar; Akhter, Zareen; Dinnebier, Robert E.

    2016-05-01

    Two new ferrocene derivatives with amide linkages were synthesized by the condensation of 4-ferrocenylaniline with n-alkyl acid chloride derivatives as pristine orange solids in good yields. FTIR and 1H/13C NMR studies have confirmed the basic structure of the molecules with the involvement of intermolecular H-bonding, which together with the ferrocene-like packing ensures the stability of the crystal structure. Crystal structures for both compounds were solved by Rietveld refinements of high resolution X-ray powder diffraction data. The XRD results show that both compounds crystallize in the monoclinic space group P21/c. The primary feature of the crystal structure is a double layer of ferrocenyl groups stretched out in the b-c -plane perpendicular to the a-axis, with packing of the ferrocenyl groups occurring in a manner similar to that of pure ferrocene. Despite the close structural similarity, both compounds differ in the optimized geometry of respective Ferrocene conformers. The Cp rings are eclipsed for one Ferrocene conformer and close to staggered for the other, owing to the low energy barrier for the rotation of a cyclopentadienyl ring relative to the rest of the molecule.

  14. SYNTHESIS AND BIOLOGICAL ACTIVITY OF AMIDE DERIVATIVES OF GINKGOLIDE A

    LI-HONG HU; ZHONG-LIANG CHEN; YU-YUAN XIE

    2001-01-01

    Amide derivatives of ginkgolide A were prepared and evaluated for their in vitro ability to inhibit the PAF-induced aggregation of rabbit platelets. They showed less activities than their parent compound ginkgolide A.

  15. A specific acid [alpha]-glucosidase in lamellar bodies of the human lung

    Vries, A.C.J. de; Schram, A.W.; Tager, J.M.; Batenburg, J.J.

    2006-01-01

    In the present investigation, we have demonstrated that three lysosomal-type hydrolases, alpha-glucosidase, alpha-mannosidase and a phosphatase, are present in lamellar bodies isolated from adult human lung. The hydrolase activities that were studied, all showed an acidic pH optimum, which is charac

  16. Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae

    French, Jarrod B.; Ealick, Steven E. (Cornell)

    2011-07-19

    The stereospecific oxidative degradation of uric acid to (S)-allantoin has recently been demonstrated to proceed via two unstable intermediates and requires three separate enzymatic reactions. The second step of this reaction, the conversion of 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, is catalyzed by HIU hydrolase (HIUH). The high-resolution crystal structure of HIUH from the opportunistic pathogen Klebsiella pneumoniae (KpHIUH) has been determined. KpHIUH is a homotetrameric protein that, based on sequence and structural similarity, belongs to the transthyretin-related protein family. In addition, the steady-state kinetic parameters for this enzyme and four active-site mutants have been measured. These data provide valuable insight into the functional roles of the active-site residues. Based upon the structural and kinetic data, a mechanism is proposed for the KpHIUH-catalyzed reaction.

  17. Phase space investigation of the lithium amide halides

    Davies, Rosalind A. [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Hydrogen and Fuel Cell Group, School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Hewett, David R.; Korkiakoski, Emma [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Thompson, Stephen P. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Anderson, Paul A., E-mail: p.a.anderson@bham.ac.uk [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2015-10-05

    Highlights: • The lower limits of halide incorporation in lithium amide have been investigated. • The only amide iodide stoichiometry observed was Li{sub 3}(NH{sub 2}){sub 2}I. • Solid solutions were observed in both the amide chloride and amide bromide systems. • A 46% reduction in chloride content resulted in a new phase: Li{sub 7}(NH{sub 2}){sub 6}Cl. • New low-chloride phase maintained improved H{sub 2} desorption properties of Li{sub 4}(NH{sub 2}){sub 3}Cl. - Abstract: An investigation has been carried out into the lower limits of halide incorporation in lithium amide (LiNH{sub 2}). It was found that the lithium amide iodide Li{sub 3}(NH{sub 2}){sub 2}I was unable to accommodate any variation in stoichiometry. In contrast, some variation in stoichiometry was accommodated in Li{sub 7}(NH{sub 2}){sub 6}Br, as shown by a decrease in unit cell volume when the bromide content was reduced. The amide chloride Li{sub 4}(NH{sub 2}){sub 3}Cl was found to adopt either a rhombohedral or a cubic structure depending on the reaction conditions. Reduction in chloride content generally resulted in a mixture of phases, but a new rhombohedral phase with the stoichiometry Li{sub 7}(NH{sub 2}){sub 6}Cl was observed. In comparison to LiNH{sub 2}, this new low-chloride phase exhibited similar improved hydrogen desorption properties as Li{sub 4}(NH{sub 2}){sub 3}Cl but with a much reduced weight penalty through addition of chloride. Attempts to dope lithium amide with fluoride ions have so far proved unsuccessful.

  18. Phase space investigation of the lithium amide halides

    Highlights: • The lower limits of halide incorporation in lithium amide have been investigated. • The only amide iodide stoichiometry observed was Li3(NH2)2I. • Solid solutions were observed in both the amide chloride and amide bromide systems. • A 46% reduction in chloride content resulted in a new phase: Li7(NH2)6Cl. • New low-chloride phase maintained improved H2 desorption properties of Li4(NH2)3Cl. - Abstract: An investigation has been carried out into the lower limits of halide incorporation in lithium amide (LiNH2). It was found that the lithium amide iodide Li3(NH2)2I was unable to accommodate any variation in stoichiometry. In contrast, some variation in stoichiometry was accommodated in Li7(NH2)6Br, as shown by a decrease in unit cell volume when the bromide content was reduced. The amide chloride Li4(NH2)3Cl was found to adopt either a rhombohedral or a cubic structure depending on the reaction conditions. Reduction in chloride content generally resulted in a mixture of phases, but a new rhombohedral phase with the stoichiometry Li7(NH2)6Cl was observed. In comparison to LiNH2, this new low-chloride phase exhibited similar improved hydrogen desorption properties as Li4(NH2)3Cl but with a much reduced weight penalty through addition of chloride. Attempts to dope lithium amide with fluoride ions have so far proved unsuccessful

  19. Artists with Arthritis Create Beauty amid Pain

    Alan; Mozes; 蔡峥伟

    2000-01-01

    得此来稿,我们曾犹豫再三,是否刊用此文。因为,其内容给人的第一印象颇有点离奇。Artists with Arthritis Create Beauty amid Pain,怎么可能呢?细读之下,你也许会觉得,此文虽是一家之言,但也并非荒唐。尤其是本文的收尾句,笔锋一转,抖出了妙言: ...in addition to the emotional support such stories can give RA patients,there are now new drug options that far surpass the treatment choices Renoir faced. 此句是否可译:除了此类故事能够给患风湿病者一种情感上的支持之外,现在可选的新药要比Renoir(雷诺阿,法国印象派画家。主要作品有《包厢》、《游船上的午餐》、《浴女》等。)时代强得多。

  20. The oxalic acid: 2-chloroacetamide crystallization: A new revelation

    Chitra, R.; Choudhury, R. R.; Capet, Frederic; Roussel, Pascal

    2013-02-01

    The OH of COOH can acts as both donor and acceptor of hydrogen bond. OH of COOH as an acceptor was primarily observed in Oxalic acid Amide complexes. In order to further understand the packing in these complexes, oxalic acid was complexed with 2-tricholoroacetamide. This crystallization resulted in the formation of ammonium tetraoxalate dehydrate. A result similar to what was observed in complexation of oxalic acid with amide containing amino acids (asparagine and glutamine). Interestingly in all these cases, the amide bond is broken, to form the ammonium ion when trying to complex with oxalic acid.

  1. Potent Urea and Carbamate Inhibitors of Soluble Epoxide Hydrolases

    Morisseau, Christophe; Goodrow, Marvin H.; Dowdy, Deanna; Zheng, Jiang; Greene, Jessica F.; Sanborn, James R.; Hammock, Bruce D.

    1999-08-01

    The soluble epoxide hydrolase (sEH) plays a significant role in the biosynthesis of inflammation mediators as well as xenobiotic transformations. Herein, we report the discovery of substituted ureas and carbamates as potent inhibitors of sEH. Some of these selective, competitive tightbinding inhibitors with nanomolar Ki values interacted stoichiometrically with the homogenous recombinant murine and human sEHs. These inhibitors enhance cytotoxicity of trans-stilbene oxide, which is active as the epoxide, but reduce cytotoxicity of leukotoxin, which is activated by epoxide hydrolase to its toxic diol. They also reduce toxicity of leukotoxin in vivo in mice and prevent symptoms suggestive of acute respiratory distress syndrome. These potent inhibitors may be valuable tools for testing hypotheses of involvement of diol and epoxide lipids in chemical mediation in vitro or in vivo systems.

  2. [GH10 Family of Glycoside Hydrolases: Structure and Evolutionary Connections].

    Naumoff, D G

    2016-01-01

    Evolutionary connections were analyzed for endo-β-xylanases, which possess the GH10 family catalytic domains. A homology search yielded thrice as many proteins as are available from the Carbohydrate-Active Enzymes (CAZy) database. Lateral gene transfer was shown to play an important role in evolution of bacterial proteins of the family, especially in the phyla Acidobacteria, Cyanobacteria, Planctomycetes, Spirochaetes, and Verrucomicrobia. In the case of Verrucomicrobia, 23 lateral transfers from organisms of other phyla were detected. Evolutionary relationships were observed between the GH10 family domains and domains with the TIM-barrel tertiary structure from several other glycosidase families. The GH39 family of glycoside hydrolases showed the closest relationship. Unclassified homologs were grouped into 12 novel families of putative glycoside hydrolases (GHL51-GHL62). PMID:27028821

  3. The structure of allophanate hydrolase from Granulibacter bethesdensis provides insights into substrate specificity in the amidase signature family¶

    Lin, Yi; St. Maurice, Martin

    2013-01-01

    Allophanate hydrolase (AH) catalyzes the hydrolysis of allophanate, an intermediate in atrazine degradation and urea catabolism pathways, to NH3 and CO2. AH belongs to the amidase signature family, which is characterized by a conserved block of 130 amino acids rich in Gly and Ser and a Ser-cisSer-Lys catalytic triad. In the present study, the first structures of AH were solved from Granulibacter bethesdensis, with and without the substrate analog malonate, to 2.2 Å and 2.8 Å, respectively. Th...

  4. Conformational Variability of Organophosphorous Hydrolase upon Soman and Paraoxon Binding

    Gomes, Diego E.B.; Lins, Roberto D.; Pascutti, Pedro G.; Lei, Chenghong; Soares, Thereza A.

    2011-01-01

    The bacterial enzyme organophosphorous hydrolase (OPH) exhibits both catalytic and substrate promiscuity. It hydrolyzes bonds in a variety of phosphotriester (P-O), phosphonothioate (P-S), phosphofluoridate (P-F) and phosphonocyanate (F-CN) compounds. However, its catalytic efficiency varies markedly for different substrates, limiting the broad-range application of OPH as catalyst in the bioremediation of pesticides and chemical war agents. In the present study, pKa calculations and multiple ...

  5. Hydroxynitrile Lyases with α/β-Hydrolase Fold: Two Enzymes with Almost Identical 3D Structures but Opposite Enantioselectivities and Different Reaction Mechanisms

    Andexer, Jennifer N; Staunig, Nicole; Eggert, Thorsten; Kratky, Christoph; Pohl, Martina; Gruber, Karl

    2012-01-01

    Hydroxynitrile lyases (HNLs) catalyze the cleavage of cyanohydrins to yield hydrocyanic acid (HCN) and the respective carbonyl compound and are key enzymes in the process of cyanogenesis in plants. In organic syntheses, HNLs are used as biocatalysts for the formation of enantiopure cyanohydrins. We determined the structure of the recently identified, R-selective HNL from Arabidopsis thaliana (AtHNL) at a crystallographic resolution of 2.5 Å. The structure exhibits an α/β-hydrolase fold, very ...

  6. Oxidoreductive Cellulose Depolymerization by the Enzymes Cellobiose Dehydrogenase and Glycoside Hydrolase 61▿†

    Langston, James A.; Shaghasi, Tarana; Abbate, Eric; Feng XU; Vlasenko, Elena; Matt D. Sweeney

    2011-01-01

    Several members of the glycoside hydrolase 61 (GH61) family of proteins have recently been shown to dramatically increase the breakdown of lignocellulosic biomass by microbial hydrolytic cellulases. However, purified GH61 proteins have neither demonstrable direct hydrolase activity on various polysaccharide or lignacious components of biomass nor an apparent hydrolase active site. Cellobiose dehydrogenase (CDH) is a secreted flavocytochrome produced by many cellulose-degrading fungi with no w...

  7. Activity based protein profiling to detect serine hydrolase alterations in virus infected cells

    MdShahiduzzaman; KevinM.Coombs

    2012-01-01

    Activity-based protein profiling (ABPP) is a newly emerging technique that uses active site-directed probes to monitor the functional status of enzymes. Serine hydrolases are one of the largest families of enzymes in mammals. More than 200 serine hydrolases have been identified, but little is known about their specific roles. Serine hydrolases are involved in a variety of physiological functions, including digestion, immune response, blood coagulation, and reproduction. ABPP has been used rec...

  8. Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon

    Tyler, Ludmila [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Bragg, Jennifer [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Wu, Jiajie [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Yang, Xiaohan [ORNL; Tuskan, Gerald A [ORNL; Vogel, John [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany

    2010-01-01

    Background Glycoside hydrolases cleave the bond between a carbohydrate and another carbohydrate, a protein, lipid or other moiety. Genes encoding glycoside hydrolases are found in a wide range of organisms, from archea to animals, and are relatively abundant in plant genomes. In plants, these enzymes are involved in diverse processes, including starch metabolism, defense, and cell-wall remodeling. Glycoside hydrolase genes have been previously cataloged for Oryza sativa (rice), the model dicotyledonous plant Arabidopsis thaliana, and the fast-growing tree Populus trichocarpa (poplar). To improve our understanding of glycoside hydrolases in plants generally and in grasses specifically, we annotated the glycoside hydrolase genes in the grasses Brachypodium distachyon (an emerging monocotyledonous model) and Sorghum bicolor (sorghum). We then compared the glycoside hydrolases across species, both at the whole-genome level and at the level of individual glycoside hydrolase families. Results We identified 356 glycoside hydrolase genes in Brachypodium and 404 in sorghum. The corresponding proteins fell into the same 34 families that are represented in rice, Arabidopsis, and poplar, helping to define a glycoside hydrolase family profile which may be common to flowering plants. Examination of individual glycoside hydrolase familes (GH5, GH13, GH18, GH19, GH28, and GH51) revealed both similarities and distinctions between monocots and dicots, as well as between species. Shared evolutionary histories appear to be modified by lineage-specific expansions or deletions. Within families, the Brachypodium and sorghum proteins generally cluster with those from other monocots. Conclusions This work provides the foundation for further comparative and functional analyses of plant glycoside hydrolases. Defining the Brachypodium glycoside hydrolases sets the stage for Brachypodium to be a monocot model for investigations of these enzymes and their diverse roles in planta. Insights

  9. Inactivation of epoxide hydrolase by catalysis-induced formation of isoaspartate

    van Loo, Bert; Permentier, Hjalmar P.; Kingma, Jaap; Baldascini, Helen; Janssen, Dick B.

    2008-01-01

    Epoxide hydrolases catalyze hydrolytic epoxide ring-opening, most often via formation of a covalent hydroxyalkyl-enzyme intermediate. A mutant of Agrobacterium radiobacter epoxide hydrolase, in which the phenylalanine residue that flanks the invariant catalytic aspartate nucleophile is replaced by a threonine, exhibited inactivation during conversion when the (R)-enantiomer of para-nitrostyrene epoxide was used as substrate. HPLC analysis of tryptic fragments of the epoxide hydrolase, followe...

  10. X-ray structure of potato epoxide hydrolase sheds light on substrate specificity in plant enzymes

    Mowbray, Sherry L.; Elfström, Lisa T.; Ahlgren, Kerstin M; Andersson, C. Evalena; Widersten, Mikael

    2006-01-01

    Epoxide hydrolases catalyze the conversion of epoxides to diols. The known functions of such enzymes include detoxification of xenobiotics, drug metabolism, synthesis of signaling compounds, and intermediary metabolism. In plants, epoxide hydrolases are thought to participate in general defense systems. In the present study, we report the first structure of a plant epoxide hydrolase, one of the four homologous enzymes found in potato. The structure was solved by molecular replacement and refi...

  11. Purification and characterization of a novel chlorpyrifos hydrolase from Cladosporium cladosporioides Hu-01.

    Yan Gao

    Full Text Available Chlorpyrifos is of great environmental concern due to its widespread use in the past several decades and its potential toxic effects on human health. Thus, the degradation study of chlorpyrifos has become increasing important in recent years. A fungus capable of using chlorpyrifos as the sole carbon source was isolated from organophosphate-contaminated soil and characterized as Cladosporium cladosporioides Hu-01 (collection number: CCTCC M 20711. A novel chlorpyrifos hydrolase from cell extract was purified 35.6-fold to apparent homogeneity with 38.5% overall recovery by ammoniumsulfate precipitation, gel filtration chromatography and anion-exchange chromatography. It is a monomeric structure with a molecular mass of 38.3 kDa. The pI value was estimated to be 5.2. The optimal pH and temperature of the purified enzyme were 6.5 and 40°C, respectively. No cofactors were required for the chlorpyrifos-hydrolysis activity. The enzyme was strongly inhibited by Hg²⁺, Fe³⁺, DTT, β-mercaptoethanol and SDS, whereas slight inhibitory effects (5-10% inhibition were observed in the presence of Mn²⁺, Zn²⁺, Cu²⁺, Mg²⁺, and EDTA. The purified enzyme hydrolyzed various organophosphorus insecticides with P-O and P-S bond. Chlorpyrifos was the preferred substrate. The Km and Vmax values of the enzyme for chlorpyrifos were 6.7974 μM and 2.6473 μmol·min⁻¹, respectively. Both NH2-terminal sequencing and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometer (MALDI-TOF-MS identified an amino acid sequence MEPDGELSALTQGANS, which shared no similarity with any reported organophosphate-hydrolyzing enzymes. These results suggested that the purified enzyme was a novel hydrolase and might conceivably be developed to fulfill the practical requirements to enable its use in situ for detoxification of chlorpyrifos. Finally, this is the first described chlorpyrifos hydrolase from fungus.

  12. N-(3-Methylphenylsuccinamic acid

    B. Thimme Gowda

    2010-02-01

    Full Text Available In the crystal structure of the title compound, C11H13NO3, the conformations of the N—H and C=O bonds in the amide segment are anti to each other, and that of the amide H atom is anti to the meta-methyl group in the benzene ring. Furthermore, the conformations of the amide oxygen and the carbonyl O atom of the acid segment are also anti to the adjacent –CH2 groups. The C=O and O—H bonds of the acid group are syn to each other. In the crystal, the molecules are packed into infinite chains through intermolecular N—H...O and O—H...O hydrogen bonds.

  13. Engineered bacterial polyester hydrolases efficiently degrade polyethylene terephthalate due to relieved product inhibition.

    Wei, Ren; Oeser, Thorsten; Schmidt, Juliane; Meier, René; Barth, Markus; Then, Johannes; Zimmermann, Wolfgang

    2016-08-01

    Recent studies on the enzymatic degradation of synthetic polyesters have shown the potential of polyester hydrolases from thermophilic actinomycetes for modifying or degrading polyethylene terephthalate (PET). TfCut2 from Thermobifida fusca KW3 and LC-cutinase (LCC) isolated from a compost metagenome are remarkably active polyester hydrolases with high sequence and structural similarity. Both enzymes exhibit an exposed active site in a substrate binding groove located at the protein surface. By exchanging selected amino acid residues of TfCut2 involved in substrate binding with those present in LCC, enzyme variants with increased PET hydrolytic activity at 65°C were obtained. The highest activity in hydrolyzing PET films and fibers were detected with the single variant G62A and the double variant G62A/I213S. Both variants caused a weight loss of PET films of more than 42% after 50 h of hydrolysis, corresponding to a 2.7-fold increase compared to the wild type enzyme. Kinetic analysis based on the released PET hydrolysis products confirmed the superior hydrolytic activity of G62A with a fourfold higher hydrolysis rate constant and a 1.5-fold lower substrate binding constant than those of the wild type enzyme. Mono-(2-hydroxyethyl) terephthalate is a strong inhibitor of TfCut2. A determination of the Rosetta binding energy suggested a reduced interaction of G62A with 2PET, a dimer of the PET monomer ethylene terephthalate. Indeed, G62A revealed a 5.5-fold lower binding constant to the inhibitor than the wild type enzyme indicating that its increased PET hydrolysis activity is the result of a relieved product inhibition by mono-(2-hydroxyethyl) terephthalate. Biotechnol. Bioeng. 2016;113: 1658-1665. © 2016 Wiley Periodicals, Inc. PMID:26804057

  14. Iron(III) Chloride mediated reduction of Bis(1-isoquinolylcarbonyl)amide to an Amide

    Rojalin Sahu; Papuli Chaliha; Vadivelu Manivannan

    2016-01-01

    In methanol, FeCl3 reacted readily with L1H (L1H = bis(1-isoquinolylcarbonyl)amide) and afforded a complex having the formula [Fe(L2)Cl2] (1) {L2− = -((1-isoquinolyl)(methoxy)methyl)isoquinoline-1-carboxamide ion}. This reaction involves reduction of one of the two carbonyl groups present in L1H to (methoxy)methyl group. A plausible mechanism for the conversion of L1H to L2− has been proposed. Determination of molecular structure of 1 confirmed this conversion. Fe(III) ion is surrounded by three nitrogen atoms of the ligand and two chloride ions, imparting a rare distorted trigonal bipyramidal N3Cl2 coordination environment.

  15. Soluble Epoxide Hydrolase as a Potential Key Factor for Human Prenatal Development.

    Cizkova, Katerina; Rajdova, Aneta; Ehrmann, Jiri

    2016-01-01

    Soluble epoxide hydrolase (sEH) converts highly active epoxyeicosatrienoic acids (EETs) generated by cytochrome P450 (CYP) epoxygenases from arachidonic acid to less active dihydroxyeicosatrienoic acids. Because of the role of EETs in processes potentially relevant to the development of organisms, EETs could be suggested as potential morphogens. Unfortunately, only little is known about sEH expression during human intrauterine development (IUD). We investigated the spatio-temporal expression pattern of sEH in human embryonic/foetal intestines, liver and kidney from the 6th to the 20th week of IUD by two-step immunohistochemistry. sEH was expressed during the whole tested period of prenatal development and its level of expression remained more or less the same during the estimated period of IUD. Distribution of CYP epoxygenases and sEH in the intestinal epithelium and the nephrogenic zone of the kidney suggests an influence of EETs on cell proliferation and differentiation and, consequently, on the development of intestines and kidney. Thus, alterations in the strict spatio-temporal pattern of expression of CYP epoxygenases and/or sEH during human prenatal development by xenobiotics could have a harmful impact for developing organisms. PMID:27144772

  16. Purification and characterization of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China

    YU Xiao-dong; LI Bo; YU Zheng-ping

    2005-01-01

    Objective: To study the physical and chemical properties of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China. Methods :The arginine ester hydrolase (AEH) was isolated from the venom of Chinese Trimeresurus mucrosqumatus by a combination of ionexchange chromatography on DEAE-Sephadex A-50, CM-Sepharose Cl-6B and gel filtration on Sephadex G-100. Results: The purified protein named TM-AEH,a glycoprotein with carbohydrate content of 0.5 % neutral hexose and 0. 75 % sialic acid,a relative molecular mass of 29.0 kDa,and an isoelectric point (pI) of 5. 2. It shares with an extinction coefficient (E0.1%/cm) of 1.332 at 280 nm,consisted of 225 amino acid residues ,and migrated as a band under reduced or non-reduced condition in basic PAGE. TM-AEH was a highly thermostable protein and was stable to pH changes between 5 and 9. The optimum temperature and optimum pH were 55℃ and 8. 4 for its catalytic activity respectively,which was inhibited by Fe3+ and Cu2+. Conclusion:This protein can exhibit higher BAEE-hydrolysing activity and fibrinogenolytic activity as compared to that of whole venom.

  17. Photophysical studies on the interaction of amides with Bovine Serum Albumin (BSA) in aqueous solution: Fluorescence quenching and protein unfolding

    Kumaran, R., E-mail: kumaranwau@rediffmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College, Arumbakkam, Chennai 600106 (India); Ramamurthy, P. [National Centre for Ultrafast Processes, University of Madras, Sekhizar Campus, Taramani, Chennai 600113 (India)

    2014-04-15

    Addition. of amides containing a H-CO(NH{sub 2}) or CH{sub 3}-CO(NH{sub 2}) framework to BSA results in a fluorescence quenching. On the contrary, fluorescence enhancement with a shift in the emission maximum towards the blue region is observed on the addition of dimethylformamide (DMF) (H-CON(CH{sub 3}){sub 2}). Fluorescence quenching accompanied initially with a shift towards the blue region and a subsequent red shift in the emission maximum of BSA is observed on the addition of formamide (H-CO(NH{sub 2})), whereas a shift in the emission maximum only towards the red region results on the addition of acetamide (CH{sub 3}-CONH{sub 2}). Steady state emission spectral studies reveal that amides that possess a free NH{sub 2} and N(CH{sub 3}){sub 2} moiety result in fluorescence quenching and enhancement of BSA respectively. The 3D contour spectral studies of BSA with formamide exhibit a shift in the emission towards the red region accompanied with fluorescence quenching, which indicates that the tryptophan residues of the BSA are exposed to a more polar environment. Circular Dichroism (CD) studies of BSA with amides resulted in a gradual decrease in the α-helical content of BSA at 208 nm, which confirms that there is a conformational change in the native structure of BSA. Time-resolved fluorescence studies illustrate that the extent of buried trytophan moieties exposed to the aqueous phase on the addition of amides follows the order DMFamides. Amides act as a hydrogen-bonding donor and acceptor resulting in a hydrogen-bonding interaction with amino and carboxy moieties (amino acids) present in BSA. The fact that the –NH{sub 2} hydrogen and the carbonyl oxygen of amide form a concerted hydrogen-bonding network with the carbonyl oxygen and the amino moieties of amino acids respectively is established from fluorescence methods. -- Highlights:

  18. Nickel-catalysed Suzuki-Miyaura coupling of amides

    Weires, Nicholas A.; Baker, Emma L.; Garg, Neil K.

    2016-01-01

    The Suzuki-Miyaura coupling has become one of the most important and prevalent methods for the construction of C-C bonds. Although palladium catalysis has historically dominated the field, the use of nickel catalysis has become increasingly widespread because of its unique ability to cleave carbon-heteroatom bonds that are unreactive towards other transition metals. We report the first nickel-catalysed Suzuki-Miyaura coupling of amides, which proceeds by an uncommon cleavage of the amide C-N bond after N-tert-butoxycarbonyl activation. The methodology is mild, functional-group tolerant and can be strategically employed in sequential transition-metal-catalysed cross-coupling sequences to unite heterocyclic fragments. These studies demonstrate that amides, despite classically considered inert substrates, can be harnessed as synthons for use in reactions that form C-C bonds through cleavage of the C-N bond using non-precious metal catalysis.

  19. VCD Robustness of the Amide-I and Amide-II Vibrational Modes of Small Peptide Models.

    Góbi, Sándor; Magyarfalvi, Gábor; Tarczay, György

    2015-09-01

    The rotational strengths and the robustness values of amide-I and amide-II vibrational modes of For(AA)n NHMe (where AA is Val, Asn, Asp, or Cys, n = 1-5 for Val and Asn; n = 1 for Asp and Cys) model peptides with α-helix and β-sheet backbone conformations were computed by density functional methods. The robustness results verify empirical rules drawn from experiments and from computed rotational strengths linking amide-I and amide-II patterns in the vibrational circular dichroism (VCD) spectra of peptides with their backbone structures. For peptides with at least three residues (n ≥ 3) these characteristic patterns from coupled amide vibrational modes have robust signatures. For shorter peptide models many vibrational modes are nonrobust, and the robust modes can be dependent on the residues or on their side chain conformations in addition to backbone conformations. These robust VCD bands, however, provide information for the detailed structural analysis of these smaller systems. PMID:26087405

  20. Carboxylic ester hydrolases in mitochondria from rat skeletal muscle

    Kirkeby, S; Moe, D; Zelander, T

    1990-01-01

    organophosphate and organomercury. The activity of the indoxyl acetate esterases was enhanced by the non-ionic detergents Tween-40 and Lubrol. After freezing, thawing and high speed centrifugation most of the alpha-naphthyl acetate splitting enzymes were found in the supernatant, indicating that the enzymes are......A mitochondrial pellet, prepared from rat skeletal muscle, contained a number of carboxylic ester hydrolase isoenzymes. The esterases which split alpha-naphthyl acetate were organophosphate sensitive, whereas two out of three indoxyl acetate hydrolysing enzymes were resistant to both...

  1. Identification of the growth hormone-releasing hormone analogue [Pro1, Val14]-hGHRH with an incomplete C-term amidation in a confiscated product.

    Esposito, Simone; Deventer, Koen; Van Eenoo, Peter

    2014-01-01

    In this work, a modified version of the 44 amino acid human growth hormone-releasing hormone (hGHRH(1-44)) containing an N-terminal proline extension, a valine residue in position 14, and a C-terminus amidation (sequence: PYADAIFTNSYRKVVLGQLSARKLLQDIMSRQQGESNQERGARARL-NH2 ) has been identified in a confiscated product by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Investigation of the product suggests also an incomplete C-term amidation. Similarly to other hGHRH analogues, available in black markets, this peptide can potentially be used as performance-enhancing drug due to its growth hormone releasing activity and therefore it should be considered as a prohibited substance in sport. Additionally, the presence of partially amidated molecule reveals the poor pharmaceutical quality of the preparation, an aspect which represents a big concern for public health as well. PMID:25283153

  2. New GABA amides activating GABA A-receptors

    Peter Raster; Andreas Späth; Svetlana Bultakova; Pau Gorostiza; Burkhard König; Piotr Bregestovski

    2013-01-01

    We have prepared a series of new and some literature-reported GABA-amides and determined their effect on the activation of GABAA-receptors expressed in CHO cells. Special attention was paid to the purification of the target compounds to remove even traces of GABA contaminations, which may arise from deprotection steps in the synthesis. GABA-amides were previously reported to be partial, full or superagonists. In our hands these compounds were not able to activate GABAA-receptor channels in wh...

  3. The temperature dependent amide I band of crystalline acetanilide

    The temperature dependent anomalous peak in the amide I band of crystalline acetanilide is thought to be due to self-trapped states. On the contrary, according to the present model, the anomalous peak comes from the fraction of ACN molecules strongly hydrogen-bonded to a neighboring ACN molecule, and its intensity decreases because, on average, this fraction decreases as temperature increases. This model provides, for the first time, an integrated and theoretically consistent view of the temperature dependence of the full amide I band and a qualitative explanation of some of the features of nonlinear pump–probe experiments.

  4. Carbonyl 13C NMR spectrum of basin pancreatic trypsin inhibitor: resonance assignments by selective amide hydrogen isotope labeling and detection of isotope effects on 13C nuclear shielding

    The carbonyl region of the natural abundance 13C nuclear magnetic resonance (NMR) spectrum of basic pancreatic trypsin inhibitor is examined, and 65 of the 66 expected signals are characterized at varying pH and temperature. Assignments are reported for over two-thirds of the signals, including those of all buried backbone amide groups with slow proton exchange and all side-chain carbonyl groups. This is the first extensively assigned carbonyl spectrum for any protein. A method for carbonyl resonance assignments utilizing amide proton exchange and isotope effects on nuclear shielding is described in detail. The assignments are made by establishing kinetic correlation between effects of amide proton exchange observed in the carbonyl 13C region with development of isotope effects and in the amide proton region with disappearance of preassigned resonances. Several aspects of protein structure and dynamics in solution may be investigated by carbonyl 13C NMR spectroscopy. Some effects of side-chain primary amide group hydrolysis are described. The main interest is on information about intramolecular hydrogen-bond energies and changes in the protein due to amino acid replacements by chemical modification or genetic engineering

  5. Activity based protein profiling to detect serine hydrolase alterations in virus infected cells

    MdShahiduzzaman

    2012-08-01

    Full Text Available Activity based protein profiling (ABPP is a newly emerging technique that uses active site-directed probes to monitor the functional status of enzymes. Serine hydrolases are one of the largest families of enzymes in mammals. More than 200 serine hydrolases have been identified but little is known about their specific roles. Serine hydrolases are involved in a variety of physiological functions, including digestion, immune response, blood coagulation and reproduction. ABPP has been used recently to investigate host-virus interactions and to understand the molecular pathogenesis of virus infections. Monitoring the altered serine hydrolases during viral infection gives insight into the catalytic activity of these enzymes that will help to identify novel targets for diagnostic and therapeutic application. This review presents the usefulness of ABPP in detecting and analyzing functional annotation of host cell serine hydrolases as a result of host-virus interaction.

  6. Alternative methods of making [11C]amides: Application to the preparation of 5-HT1A receptor radioligands

    Many ligands for brain 5-HT1A receptors contain an amide group that is subject to hydrolysis in vivo. In the development of radioligands for use with positron emission tomography (PET), labelling in the carbonyl function of an amide group may be advantageous for avoiding radioactive metabolites that would readily enter the brain to confound PET receptor measurements. Several methods of labelling secondary and tertiary amides in their carbonyl functions with 11C (T1/2 = 20.4 min) have been developed over the past two decades or so. These methods include reaction of a [carbonyl-11C]acid chloride, [carboxyl-11C]magnesium halide carboxylate or [carboxyl-11C]acid with an amine or reaction of [11C]carbon monoxide with an amine plus an aryl halide, alkyl halide or aryl triflate. Some of these processes are successfully promoted with microwaves, palladium complexes, light or thermally initiated radicals. These methods are surveyed here and especially exemplified from research on the development of 5-HT1A receptor radioligands for brain imaging applications with PET. (author)

  7. Kinetic isotope effects support the twisted amide mechanism of Pin1 peptidyl-prolyl isomerase.

    Mercedes-Camacho, Ana Y; Mullins, Ashley B; Mason, Matthew D; Xu, Guoyan G; Mahoney, Brendan J; Wang, Xingsheng; Peng, Jeffrey W; Etzkorn, Felicia A

    2013-11-01

    The Pin1 peptidyl-prolyl isomerase catalyzes isomerization of pSer/pThr-Pro motifs in regulating the cell cycle. Peptide substrates, Ac-Phe-Phe-phosphoSer-Pro-Arg-p-nitroaniline, were synthesized in unlabeled form, and with deuterium-labeled Ser-d3 and Pro-d7 amino acids. Kinetic data were collected as a function of Pin1 concentration to measure kinetic isotope effects (KIEs) on catalytic efficiency (kcat/Km). The normal secondary (2°) KIE value measured for the Ser-d3 substrate (kH/kD = 1.6 ± 0.2) indicates that the serine carbonyl does not rehybridize from sp(2) to sp(3) in the rate-determining step, ruling out a nucleophilic addition mechanism. The normal 2° KIE can be explained by hyperconjugation between Ser α-C-H/D and C═O and release of steric strain upon rotation of the amide bond from cis to syn-exo. The inverse 2° KIE value (kH/kD = 0.86 ± 0.08) measured for the Pro-d7 substrate indicates rehybridization of the prolyl nitrogen from sp(2) to sp(3) during the rate-limiting step of isomerization. No solvent kinetic isotope was measured by NMR exchange spectroscopy (kH2O/kD2O = 0.92 ± 0.12), indicating little or no involvement of exchangeable protons in the mechanism. These results support the formation of a simple twisted amide transition state as the mechanism for peptidyl prolyl isomerization catalyzed by Pin1. A model of the reaction mechanism is presented using crystal structures of Pin1 with ground state analogues and an inhibitor that resembles a twisted amide transition state. PMID:24116866

  8. cis–trans-Amide isomerism of the 3,4-dehydroproline residue, the ‘unpuckered’ proline

    2016-01-01

    Summary Proline (Pro) is an outstanding amino acid in various biochemical and physicochemical perspectives, especially when considering the cis–trans isomerism of the peptidyl-Pro amide bond. Elucidation of the roles of Pro in chemical or biological systems and engineering of its features can be addressed with various Pro analogues. Here we report an experimental work investigating the basic physicochemical properties of two Pro analogues which possess a 3,4-double bond: 3,4-dehydroproline and 4-trifluoromethyl-3,4-dehydroproline. Both indicate a flat pyrroline ring in their crystal structures, in agreement with previous theoretical calculations. In solution, the peptide mimics exhibit an almost unchanged equilibrium of the trans/cis ratios compared to that of Pro and 4-trifluoromethylproline derivatives. Finally we demonstrate that the 3,4-double bond in the investigated structures leads to an increase of the amide rotational barriers, presumably due to an interplay with the transition state.

  9. Mechanistic investigations of unsaturated glucuronyl hydrolase from Clostridium perfringens.

    Jongkees, Seino A K; Yoo, Hayoung; Withers, Stephen G

    2014-04-18

    Experiments were carried out to probe the details of the hydration-initiated hydrolysis catalyzed by the Clostridium perfringens unsaturated glucuronyl hydrolase of glycoside hydrolase family 88 in the CAZy classification system. Direct (1)H NMR monitoring of the enzymatic reaction detected no accumulated reaction intermediates in solution, suggesting that rearrangement of the initial hydration product occurs on-enzyme. An attempt at mechanism-based trapping of on-enzyme intermediates using a 1,1-difluoro-substrate was unsuccessful because the probe was too deactivated to be turned over by the enzyme. Kinetic isotope effects arising from deuterium-for-hydrogen substitution at carbons 1 and 4 provide evidence for separate first-irreversible and overall rate-determining steps in the hydration reaction, with two potential mechanisms proposed to explain these results. Based on the positioning of catalytic residues in the enzyme active site, the lack of efficient turnover of a 2-deoxy-2-fluoro-substrate, and several unsuccessful attempts at confirmation of a simpler mechanism involving a covalent glycosyl-enzyme intermediate, the most plausible mechanism is one involving an intermediate bearing an epoxide on carbons 1 and 2. PMID:24573682

  10. Acetylcarnitine hydrolase activity in bovine caudal epididymal spermatozoa

    Bruns, K.; Foster, R.A.; Casillas, E.R.

    1986-05-01

    Recently, the authors identified mM concentrations of acetylcarnitine in epidiymal fluids and have investigated the metabolism of acetylcarnitine by bovine and hamster caudal epididymal spermatozoa. (1-/sup 14/C)acetyl-L-carnitine is oxidized to /sup 14/CO/sub 2/ by washed, intact hamster and bovine sperm at maximal rates of 8.4 and 15.2 nmol/hr/10/sup 7/ cells respectively. Conversely, the carnitine moiety of acetyl-L-(/sup 3/H-methyl)carnitine is not accumulated by sperm under similar conditions. Hydrolysis of (/sup 3/H)acetyl-L-carnitine and competition of uptake of (/sup 3/H)acetate by unlabeled acetate was demonstrated in incubations of intact cells of both species. The amount of (/sup 3/H)acetate accumulated in the incubation medium is time-dependent and also depends on the concentration of unlabeled acetate. A partial solubilization of acetylcarnitine hydrolase activity from washed, intact bovine caudal epididymal spermatozoa in buffer or 0.01% Triton X-100 is observed. There is an enrichment of acetylcarnitine hydrolase activity in purified plasma membranes from bovine caudal epididymal spermatozoa when compared to the activity present in broken cell preparations or other cellular fractions. The results suggest that acetylcarnitine is a substrate for spermatozoa as they traverse the epididymis.

  11. Acetylcarnitine hydrolase activity in bovine caudal epididymal spermatozoa

    Recently, the authors identified mM concentrations of acetylcarnitine in epidiymal fluids and have investigated the metabolism of acetylcarnitine by bovine and hamster caudal epididymal spermatozoa. [1-14C]acetyl-L-carnitine is oxidized to 14CO2 by washed, intact hamster and bovine sperm at maximal rates of 8.4 and 15.2 nmol/hr/107 cells respectively. Conversely, the carnitine moiety of acetyl-L-[3H-methyl]carnitine is not accumulated by sperm under similar conditions. Hydrolysis of [3H]acetyl-L-carnitine and competition of uptake of [3H]acetate by unlabeled acetate was demonstrated in incubations of intact cells of both species. The amount of [3H]acetate accumulated in the incubation medium is time-dependent and also depends on the concentration of unlabeled acetate. A partial solubilization of acetylcarnitine hydrolase activity from washed, intact bovine caudal epididymal spermatozoa in buffer or 0.01% Triton X-100 is observed. There is an enrichment of acetylcarnitine hydrolase activity in purified plasma membranes from bovine caudal epididymal spermatozoa when compared to the activity present in broken cell preparations or other cellular fractions. The results suggest that acetylcarnitine is a substrate for spermatozoa as they traverse the epididymis

  12. Protective mechanisms against homocysteine toxicity: the role of bleomycin hydrolase.

    Zimny, Jaroslaw; Sikora, Marta; Guranowski, Andrzej; Jakubowski, Hieronim

    2006-08-11

    Homocysteine (Hcy) editing by methionyl-tRNA synthetase results in the formation of Hcy-thiolactone and initiates a pathway that has been implicated in human disease. In addition to being cleared from the circulation by urinary excretion, Hcy-thiolactone is detoxified by the serum Hcy-thiolactonase/paraoxonase carried on high density lipoprotein. Whether Hcy-thiolactone is detoxified inside cells was unknown. Here we show that Hcy-thiolactone is hydrolyzed by an intracellular enzyme, which we have purified to homogeneity from human placenta and identified by proteomic analyses as human bleomycin hydrolase (hBLH). We have also purified an Hcy-thiolactonase from the yeast Saccharomyces cerevisiae and identified it as yeast bleomycin hydrolase (yBLH). BLH belongs to a family of evolutionarily conserved cysteine aminopeptidases, and its only known biologically relevant function was deamidation of the anticancer drug bleomycin. Recombinant hBLH or yBLH, expressed in Escherichia coli, exhibits Hcy-thiolactonase activity similar to that of the native enzymes. Active site mutations, C73A for hBLH and H369A for yBLH, inactivate Hcy-thiolactonase activities. Yeast blh1 mutants are deficient in Hcy-thiolactonase activity in vitro and in vivo, produce more Hcy-thiolactone, and exhibit greater sensitivity to Hcy toxicity than wild type yeast cells. Our data suggest that BLH protects cells against Hcy toxicity by hydrolyzing intracellular Hcy-thiolactone. PMID:16769724

  13. Marine Extremophiles: A Source of Hydrolases for Biotechnological Applications

    Gabriel Zamith Leal Dalmaso

    2015-04-01

    Full Text Available The marine environment covers almost three quarters of the planet and is where evolution took its first steps. Extremophile microorganisms are found in several extreme marine environments, such as hydrothermal vents, hot springs, salty lakes and deep-sea floors. The ability of these microorganisms to support extremes of temperature, salinity and pressure demonstrates their great potential for biotechnological processes. Hydrolases including amylases, cellulases, peptidases and lipases from hyperthermophiles, psychrophiles, halophiles and piezophiles have been investigated for these reasons. Extremozymes are adapted to work in harsh physical-chemical conditions and their use in various industrial applications such as the biofuel, pharmaceutical, fine chemicals and food industries has increased. The understanding of the specific factors that confer the ability to withstand extreme habitats on such enzymes has become a priority for their biotechnological use. The most studied marine extremophiles are prokaryotes and in this review, we present the most studied archaea and bacteria extremophiles and their hydrolases, and discuss their use for industrial applications.

  14. Electrophilic Activation of α,β-Unsaturated Amides: Catalytic Asymmetric Vinylogous Conjugate Addition of Unsaturated γ-Butyrolactones.

    Zhang, Ming; Kumagai, Naoya; Shibasaki, Masakatsu

    2016-04-11

    Although catalytic asymmetric conjugate addition reactions have remarkably advanced over the last two decades, the application of less electrophilic α,β-unsaturated carboxylic acid derivatives in this useful reaction manifold remains challenging. Herein, we report that α,β-unsaturated 7-azaindoline amides act as reactive electrophiles to participate in catalytic diastereo- and enantioselective vinylogous conjugate addition of γ-butyrolactones in the presence of a cooperative catalyst comprising of a soft Lewis acid and a Brønsted base. Reactions mostly reached completion with as little as 1 mol % of catalyst loading to give the desired conjugate adducts in a highly stereoselective manner. PMID:26970428

  15. Inhibition of Chronic Pancreatitis and Murine Pancreatic Intraepithelial Neoplasia by a Dual Inhibitor of c-RAF and Soluble Epoxide Hydrolase in LSL-KrasG12D/Pdx-1-Cre Mice

    Liao, Jie; Hwang, Sung Hee; Li, Haonan; Liu, Jun-Yan; Hammock, Bruce D.; Yang, Guang-Yu

    2016-01-01

    Mutation of Kirsten rat sarcoma viral oncogene homolog (KRAS) and chronic pancreatitis are the most common pathogenic events involved in human pancreatic carcinogenesis. In the process of long-standing chronic inflammation, aberrant metabolites of arachidonic acid play a crucial role in promoting carcinogenesis, in which the soluble epoxide hydrolase (sEH), as a pro-inflammatory enzyme, generally inactivates anti-inflammatory epoxyeicosatrienoic acids (EETs). Herein, we determined the effect ...

  16. Peptide hydrolase activities in seedlings and hormone-treated cotyledons of pumpkin (Cucurbita pepo).

    Weidhase, R A; Parthier, B

    1983-01-01

    Enzymes hydrolyzing Gly-Ala-, Met-Met- and Pro-4-phenylazo-phenylamides, and N-benzoyl-L-arginine-4-nitroanilide have been identified in germinating seeds and cotyledons of pumpkin (Cucurbita pepo). The enzyme activities per cotyledon increase markedly during the germination process, but the proportion of enhancement depends on the type of enzyme species. The increase in enzyme activities is due to de novo synthesis as shown by cycloheximide treatment and is influenced by phytohormones (cytokinins and abscissic acid). In isolated cotyledons exogenous cytokinin (benzyladenine) obviously can replace the effect of the embryo as the source of endogenous hormone. Abscissic acid counteracts the cytokinin effect. It is suggested that aminopeptidases have a biological function in reserve protein degradation of the cotyledons during seed germination. Our results do not support the assumption that the embryonic axis of the growing seedling serves as a "sink" of proteolytic products resulting in an activation of peptide hydrolases in the cotyledons, but rather de novo synthesis of these enzymes seems to be controlled by substances (phytohormones) originating from the embryo. PMID:6360167

  17. New insights into plant glycoside hydrolase family 32 in Agave species.

    Avila de Dios, Emmanuel; Gomez Vargas, Alan D; Damián Santos, Maura L; Simpson, June

    2015-01-01

    In order to optimize the use of agaves for commercial applications, an understanding of fructan metabolism in these species at the molecular and genetic level is essential. Based on transcriptome data, this report describes the identification and molecular characterization of cDNAs and deduced amino acid sequences for genes encoding fructosyltransferases, invertases and fructan exohydrolases (FEH) (enzymes belonging to plant glycoside hydrolase family 32) from four different agave species (A. tequilana, A. deserti, A. victoriae-reginae, and A. striata). Conserved amino acid sequences and a hypervariable domain allowed classification of distinct isoforms for each enzyme type. Notably however neither 1-FFT nor 6-SFT encoding cDNAs were identified. In silico analysis revealed that distinct isoforms for certain enzymes found in a single species, showed different levels and tissue specific patterns of expression whereas in other cases expression patterns were conserved both within the species and between different species. Relatively high levels of in silico expression for specific isoforms of both invertases and fructosyltransferases were observed in floral tissues in comparison to vegetative tissues such as leaves and stems and this pattern was confirmed by Quantitative Real Time PCR using RNA obtained from floral and leaf tissue of A. tequilana. Thin layer chromatography confirmed the presence of fructans with degree of polymerization (DP) greater than DP three in both immature buds and fully opened flowers also obtained from A. tequilana. PMID:26300895

  18. Cloning and Expression of Bile Salt Hydrolase Gene from Lactobacillus plantarum M1-UVS29

    Yu Chang-qing; Li Rong

    2015-01-01

    We cloned and expressed bile salt hydrolase gene ofLactobacillus plantarum M1-UVS29 inLactococcus lactis NZ9000 successfully. Gene-specific primers for amplification ofL. plantarum bsh were designed by using sequence which availabled from GenBank. The production of PCR amplicon was confirmed by sequencing and cloned into pMD18-T vector, and then recombined into expression vector pNZ8148 and yielding vector pNZ8148-BSH. pNZ8148-BSH was transferred intoLactococcus lactis NZ9000. Sequencing indicated that the clonedbsh fragment contained 995 nucleotides, and shared 99.3% sequence homology withbsh gene fromL. plantarum MBUL10. Clonedbsh fragment was successfully transduced into NICE expression system and confirmed by PCR and restriction digest. Recombinant BSH protein was analyzed by SDS-PAGE. The molecular weight of BSH protein was approximately 37 ku. Activity of the expressed protein was 0.77 µmol• min-1. The successfully expressed proteins by genetic engineering technology made the function of lactic acid bacteria be abundant and laid the foundation for further researches into cholesterol-lowering lactic acid bacterium food and probiotics.

  19. Chiral amides via copper-catalysed enantioselective conjugate addition

    Schoonen, Anne K.; Fernández-Ibáñez, M. Ángeles; Fañanás-Mastral, Martín; Teichert, Johannes F.; Feringa, Bernard

    2014-01-01

    A highly enantioselective one pot procedure for the synthesis of β-substituted amides was developed starting from the corresponding α,β-unsaturated esters. This new methodology is based on the copper-catalysed enantioselective conjugate addition of Grignard reagents to α,β-unsaturated esters and sub

  20. Insecticidal, repellent and fungicidal properties of novel trifluoromethylphenyl amides

    Twenty trifluoromethylphenyl amides were synthesized and evaluated as fungicides and as mosquito toxicants and repellents. Against Aedes aegypti larvae, (trifluoromethyl)phenyl)-3,5-dinitrobenzamide (1e) was the most toxic compound (24 h LC50 1940 nM), while against adults (trifluoromethyl)phenyl)-...

  1. Bovine intermediate pituitary alpha-amidation enzyme: preliminary characterization

    A secretory granule-associated enzymatic activity that converts mono-[125I]-D-Tyr-Val-Gly into mono-[125I]-D-Tyr-Val-NH2 has been studied. The activity is primarily soluble and shows optimal activity at pH 7 to pH 8. Amidation activity was stimulated 9-fold by addition of optimal amounts of copper (3 microM). In the presence of optimal copper, ascorbate stimulated the reaction 7-fold; none of the other reduced or oxidized cofactors tested was as effective. Taking into account the dependence of the reaction on ascorbate and molecular oxygen and the production of glyoxylate [2], it is suggested that the alpha-amidation enzyme is a monooxygenase. Lineweaver Burk plots with D-Tyr-Val-Gly as the varied substrate demonstrated Michelis-Menten type kinetics with the values of K/sub m/ and V/sub max/ increasing with the addition of ascorbate to the assay. A variety of peptides ending with a COOH-terminal Gly residue act as inhibitors of the reaction. Two synthetic peptides, gamma 2MSH and ACTH(1-14), with carboxyl termini similar to the presumed physiological substrates for the enzyme, act as competitive inhibitors with similar K1 values. It is likely that this secretory granule alpha-amidation activity is involved in the physiological biosynthetic alpha-amidation of a wide range of bioactive peptides

  2. The effect of amidation on the behaviour of antimicrobial peptides.

    Mura, Manuela; Wang, Jianping; Zhou, Yuhua; Pinna, Marco; Zvelindovsky, Andrei V; Dennison, Sarah R; Phoenix, David A

    2016-04-01

    Aurein 2.6-COOH and aurein 3.1-COOH were studied along with their naturally occurring C-terminally amidated analogues. Circular dichroism (CD) and molecular dynamic (MD) simulations were used to study the effects of amidation on the interaction of antimicrobial peptides (AMPs) with lipid bilayers. CD measurements and MD analysis suggested that both peptide analogues were predominantly random coil and adopted low levels of [Formula: see text]-helical structure in solution (peptides formed a stable [Formula: see text]-helical structure. In general, amidated analogues have a greater propensity than the non-amidated peptides to form a [Formula: see text]-helical structure. MD simulations predicted that aurein 2.6-COOH and aurein 3.1-CHOOH destabilised lipid bilayers from 1,2-dimyristoyl-sn-glycero-3-phosphocholine and 1,2-dimyristoyl-sn-glycero-3-phosphoserine via angled bilayer penetration. They also showed that aurein 2.6-CONH[Formula: see text] and aurein 3.1-CONH[Formula: see text] formed a helix horizontal to the plane of an asymmetric interface. PMID:26745958

  3. Amide-modified poly(butylene terephthalate): polycondensation

    Bennekom, van A.C.M.; Gaymans, R.J.

    1996-01-01

    The synthesis of poly(ester amide) copolymers (PBTA) based on poly(butylene terephthalate) (PBT) and nylon-4,T with the diamide of butanediamine and dimethyl terephthelate (N,N′-bis(p-carbomethoxybenzoyl)butanediamine) has been carried out. Different melt and solid state condensation reactors were u

  4. Use of triphenyl phosphate as risk mitigant for metal amide hydrogen storage materials

    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2016-04-26

    A process in a resulting product of the process in which a hydrogen storage metal amide is modified by a ball milling process using an additive of TPP. The resulting product provides for a hydrogen storage metal amide having a coating that renders the hydrogen storage metal amide resistant to air, ambient moisture, and liquid water while improving useful hydrogen storage and release kinetics.

  5. 40 CFR 721.10191 - Amides, coco, N-[3-(dibutylamino)propyl].

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- . 721.10191 Section... Substances § 721.10191 Amides, coco, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- (PMN P-06-262; CAS No. 851544-20-2)...

  6. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  7. FMRF-amide-like immunoreactivity in brain and pituitary of the hagfish Eptatretus burgeri (Cyclostomata)

    Jirikowski, G; Erhart, G; Grimmelikhuijzen, C J;

    1984-01-01

    the hypothalamus to the olfactory system and caudally to the medulla oblongata. FMRF-amide-like immunoreactivity was also found in cells of the adenohypophysis. These observations suggest that the hagfish possesses a brain FMRF-amide-like transmitter system and pituitary cells containing FMRF-amide-like material...

  8. In silico modeling of the molecular structure and binding of leukotriene A4 into leukotriene A4 hydrolase

    Paz, Paula B; Estrada, Mario R; Martinez, Juan C Garro

    2012-01-01

    A combined molecular docking and molecular structure in silico analysis on the substrate and product of leukotriene A4 hydrolase (LTA4H) was performed. The molecular structures of the substrate leukotriene A4 (LTA4) and product leukotirene B4 (LTB4) were studied through Density Functional Theory (DFT) calculations at the B3LYP/6-31+G(d) level of theory in both, gas and condensed phases. The whole LTB4 molecule was divided into three fragments (hydrophobic tail, triene motif, and a polar acidic group) which were subjected to a full conformational study employing the most stable conformations of them to build conformers of the complete molecule and geometry optimize further. LTA4 conformers structures were modeled from the LTB4 minimum energy conformers. Both, protonated and deprotonated species of LTA4 and LTB4, were analyzed according to pKa values founded in the literature. Finally, a binding model of LTA4 with LTA4 hydrolase is proposed according to docking results which show intermolecular interactions tha...

  9. α/β-Hydrolase Domain 6 Deletion Induces Adipose Browning and Prevents Obesity and Type 2 Diabetes.

    Zhao, Shangang; Mugabo, Yves; Ballentine, Gwynne; Attane, Camille; Iglesias, Jose; Poursharifi, Pegah; Zhang, Dongwei; Nguyen, Thuy Anne; Erb, Heidi; Prentki, Raphael; Peyot, Marie-Line; Joly, Erik; Tobin, Stephanie; Fulton, Stephanie; Brown, J Mark; Madiraju, S R Murthy; Prentki, Marc

    2016-03-29

    Suppression of α/β-domain hydrolase-6 (ABHD6), a monoacylglycerol (MAG) hydrolase, promotes glucose-stimulated insulin secretion by pancreatic β cells. We report here that high-fat-diet-fed ABHD6-KO mice show modestly reduced food intake, decreased body weight gain and glycemia, improved glucose tolerance and insulin sensitivity, and enhanced locomotor activity. ABHD6-KO mice also show increased energy expenditure, cold-induced thermogenesis, brown adipose UCP1 expression, fatty acid oxidation, and white adipose browning. Adipose browning and cold-induced thermogenesis are replicated by the ABHD6 inhibitor WWL70 and by antisense oligonucleotides targeting ABHD6. Our evidence suggests that one mechanism by which the lipolysis derived 1-MAG signals intrinsic and cell-autonomous adipose browning is via PPARα and PPARγ activation, and that ABHD6 regulates adipose browning by controlling signal competent 1-MAG levels. Thus, ABHD6 regulates energy homeostasis, brown adipose function, and white adipose browning and is a potential therapeutic target for obesity and type 2 diabetes. PMID:26997277

  10. Papain-like protease (PLpro) inhibitory effects of cinnamic amides from Tribulus terrestris fruits.

    Song, Yeong Hun; Kim, Dae Wook; Curtis-Long, Marcus John; Yuk, Heung Joo; Wang, Yan; Zhuang, Ningning; Lee, Kon Ho; Jeon, Kwon Seok; Park, Ki Hun

    2014-01-01

    Tribulus terrestris fruits are well known for their usage in pharmaceutical preparations and food supplements. The methanol extract of T. terrestris fruits showed potent inhibition against the papain-like protease (PLpro), an essential proteolylic enzyme for protection to pathogenic virus and bacteria. Subsequent bioactivity-guided fractionation of this extract led to six cinnamic amides (1-6) and ferulic acid (7). Compound 6 emerged as new compound possessing the very rare carbinolamide motif. These compounds (1-7) were evaluated for severe acute respiratory syndrome coronavirus (SARS-CoV) PLpro inhibitory activity to identify their potencies and kinetic behavior. Compounds (1-6) displayed significant inhibitory activity with IC50 values in the range 15.8-70.1 µM. The new cinnamic amide 6 was found to be most potent inhibitor with an IC50 of 15.8 µM. In kinetic studies, all inhibitors exhibited mixed type inhibition. Furthermore, the most active PLpro inhibitors (1-6) were proven to be present in the native fruits in high quantities by HPLC chromatogram and liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI/MS). PMID:24882413

  11. Amidation reaction of eugenyl oxyacetate ethyl ester with 1,3 diaminopropane

    Suryanti, V.; Wibowo, F. R.; Kusumaningsih, T.; Wibowo, A. H.; Khumaidah, S. A.; Wijayanti, L. A.

    2016-04-01

    Eugenol having various substituents on the aromatic ring (hydroxy, methoxy and allyl) are useful for starting material in synthesizing of its derivatives. Eugenol derivatives have shown wide future potential applications in many areas, especially as future drugs against many diseases. The aim of this work was to synthesize an amide of eugenol derivative. The starting material used was eugenol from clove oil and the reaction was conducted in 3 step reactions to give the final product. Firstly, eugenol was converted into eugenyl oxyacetate [2-(4-allyl-2-methoxyphenoxy) acetic acid] as a white crystal with 70.5% yield, which was then esterified with ethanol to have eugenyl oxyacetate ethyl ester [ethyl 2-(4-allyl-2-methoxyphenoxy) acetate] as brown liquid in 75.7%. The last step was the reaction between eugenyl oxyacetate ethyl ester and 1,3 diaminopropane to give 2-(4-allyl-2-methoxyphenoxy)-N-(3-aminopropyl) acetamide as a brown powder with 71.6% yield, where the amidation reaction was occurred.

  12. Synthesis, characterization and biological evaluation of novel α, β unsaturated amides

    Esmailzadeh, K.; Housaindokht, M. R.; Moradi, A.; esmaeili, A. A.; Sharifi, Z.

    2016-05-01

    Three derivatives of α,β unsaturated amides have been successfully synthesized via Ugi-four component (U-4CR) reaction. The interactions of the amides with calf thymus deoxyribonucleic acid (ct-DNA) have been investigated in the Tris-HCl buffer (pH = 7.4) using viscometric, spectroscopic, thermal denaturation studies, and also molecular docking. By UV-Vis absorption spectroscopy studies, adding CT-DNA to the compound solution caused the hypochromism indicates that there are interactions between the compounds and DNA base pairs. In competitive fluorescence with methylene blue as an intercalator probe, adding compounds to DNA-MB solution caused an increase in emission spectra of the complex. This could be because of compound replacing, with similar binding mode of MB, between the DNA base pairs due to release of bonded MB molecules from DNA-MB complex. Thermal denaturation studies and viscometric experiments also indicated that all three investigated compounds bind to CT-DNA by non-classical intercalation mode. Additionally, molecular docking technique predicted partial intercalation binding mode for the compounds. Also, the highest binding energy was obtained for compound 5a. These results are in agreement with results obtained by empirical methods.

  13. Actinide separation with a novel tridentate ligand, di-glycolic amide for application to partitioning process

    Yuji Sasaki; Yumi Sugo; Shoichi Tachimori [Japan Atomic Energy Research Institute, Tokai-Mura, Ibaraki-Ken (Japan)

    2000-07-01

    The tridentate neutral ligands, having two amidic carbonyl donors and an etheric oxygen, were synthesized in our laboratory and examined the extraction of actinides and fission products. Among the synthesized diglycol-amides (DGA) with varying length of alkyl chains attached to two N atoms, N,N,N',N'-tetra-octyl-3-oxa-pentane-diamide (TODGA) and N,N,N',N'-tetra-decyl-3-oxa-pentane-diamide (TDDGA), showed a sufficient solubility in n-dodecane. The extractability of both TODGA and TDDGA for actinides(Ans), i.e., U(VI), Pu(IV), Am(III), and Cm(III), in nitric acid solution was satisfactorily high and its order was in a succession of An(III), An(IV) > An(VI) > An(V). The extraction of fission products (FPs), except Zr(IV) and lanthanides(Lns), are relatively small, indicating the sufficient separation of actinides, Zr(IV) and Lns(III) from other FPs. The extraction kinetics, maximum loading in the organic phase, back-extraction behavior, and radiolytic stability of TODGA showed that TODGA is applicable to the treatment of the high level waste. (authors)

  14. Actinide separation with a novel tridentate ligand, di-glycolic amide for application to partitioning process

    The tridentate neutral ligands, having two amidic carbonyl donors and an etheric oxygen, were synthesized in our laboratory and examined the extraction of actinides and fission products. Among the synthesized diglycol-amides (DGA) with varying length of alkyl chains attached to two N atoms, N,N,N',N'-tetra-octyl-3-oxa-pentane-diamide (TODGA) and N,N,N',N'-tetra-decyl-3-oxa-pentane-diamide (TDDGA), showed a sufficient solubility in n-dodecane. The extractability of both TODGA and TDDGA for actinides(Ans), i.e., U(VI), Pu(IV), Am(III), and Cm(III), in nitric acid solution was satisfactorily high and its order was in a succession of An(III), An(IV) > An(VI) > An(V). The extraction of fission products (FPs), except Zr(IV) and lanthanides(Lns), are relatively small, indicating the sufficient separation of actinides, Zr(IV) and Lns(III) from other FPs. The extraction kinetics, maximum loading in the organic phase, back-extraction behavior, and radiolytic stability of TODGA showed that TODGA is applicable to the treatment of the high level waste. (authors)

  15. Leishmania donovani Nucleoside Hydrolase terminal domains in cross-protective immunotherapy against Leishmania amazonensis murine infection

    Dirlei eNico

    2014-06-01

    Full Text Available Nucleoside hydrolases of the Leishmania genus are vital enzymes for the replication of the DNA and conserved phylogenetic markers of the parasites. Leishmania donovani Nucleoside hydrolase (NH36 induced a main CD4+ T cell driven protective response against Leishmania chagasi infection in mice which is directed against its C-terminal domain. In this study, we used the three recombinant domains of NH36: N-terminal domain (F1, amino acids 1-103, central domain (F2 aminoacids 104-198 and C-terminal domain (F3 amino acids 199-314 in combination with saponin and assayed their immunotherapeutic effect on Balb/c mice previously infected with L. amazonensis. We identified that the F1 and F3 peptides determined strong cross-immunotherapeutic effects, reducing the size of footpad lesions to 48% and 64%, and the parasite load in footpads to 82.6% and 81%, respectively. The F3 peptide induced the strongest anti-NH36 antibody response and intradermal response (IDR against L. amazonenis and a high secretion of IFN-γ and TNF-α with reduced levels of IL-10. The F1 vaccine, induced similar increases of IgG2b antibodies and IFN-γ and TNF-α levels, but no IDR and no reduction of IL-10. The multiparameter flow cytometry analysis was used to assess the immune response after immunotherapy and disclosed that the degree of the immunotherapeutic effect is predicted by the frequencies of the CD4+ and CD8+ T cells producing IL-2 or TNF-α or both. Total frequencies and frequencies of double-cytokine CD4 T cell producers were enhanced by F1 and F3 vaccines. Collectively, our multifunctional analysis disclosed that immunotherapeutic protection improved as the CD4 responses progressed from 1+ to 2+, in the case of the F1 and F3 vaccines, and as the CD8 responses changed qualitatively from 1+ to 3+, mainly in the case of the F1 vaccine, providing new correlates of immunotherapeutic protection against cutaneous leishmaniasis in mice based on T-helper TH1 and CD8+ mediated

  16. α/β-hydrolase domain containing protein 15 (ABHD15--an adipogenic protein protecting from apoptosis.

    Evelyn Walenta

    Full Text Available Our knowledge about adipocyte metabolism and development is steadily growing, yet many players are still undefined. Here, we show that α/β-hydrolase domain containing protein 15 (Abhd15 is a direct and functional target gene of peroxisome proliferator-activated receptor gamma (PPARγ, the master regulator of adipogenesis. In line, Abhd15 is mainly expressed in brown and white adipose tissue and strongly upregulated during adipogenesis in various murine and human cell lines. Stable knockdown of Abhd15 in 3T3-L1 cells evokes a striking differentiation defect, as evidenced by low lipid accumulation and decreased expression of adipocyte marker genes. In preconfluent cells, knockdown of Abhd15 leads to impaired proliferation, which is caused by apoptosis, as we see an increased SubG1 peak, caspase 3/7 activity, and BAX protein expression as well as a reduction in anti-apoptotic BCL-2 protein. Furthermore, apoptosis-inducing amounts of palmitic acid evoke a massive increase of Abhd15 expression, proposing an apoptosis-protecting role for ABHD15. On the other hand, in mature adipocytes physiological (i.e. non-apoptotic concentrations of palmitic acid down-regulate Abhd15 expression. Accordingly, we found that the expression of Abhd15 in adipose tissue is reduced in physiological situations with high free fatty acid levels, like high-fat diet, fasting, and aging as well as in genetically obese mice. Collectively, our results position ABHD15 as an essential component in the development of adipocytes as well as in apoptosis, thereby connecting two substantial factors in the regulation of adipocyte number and size. Together with its intricate regulation by free fatty acids, ABHD15 might be an intriguing new target in obesity and diabetes research.

  17. Synthetic polyspermine imidazole-4, 5-amide as an efficient and cytotoxicity-free gene delivery system

    Duan S

    2012-07-01

    Full Text Available Shi-Yue Duan, Xue-Mei Ge, Nan Lu, Fei Wu, Weien Yuan, Tuo JinSchool of Pharmacy, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of ChinaAbstract: A chemically dynamic spermine-based polymer: polyspermine imidazole-4, 5-amide (PSIA, Mw > 7 kDa was designed, synthesized, and evaluated in terms of its ability to deliver nucleic acids. This polymer was made from an endogenous monomer professionally condensing genes in sperms, spermine, and a known safety drug metabolite, imidazole-4, 5-dicarboxylic acid, through a bis-amide bond conjugated with the imidazole ring. This polymer can condense pDNA at a W/W ratio above 10 to form polyplexes (100–200 nm in diameter, which is consistent with the observation by transmission electron microscopy (TEM, and the zeta potential was in the range of 10–20 mV. The pDNA packaged polymer was stable in phosphate buffer solution (PBS at pH 7.4 (simulated body fluid while the polyplexes were releasing pDNA into the solution at pH 5.8 (simulated endo-lysosomes due to the degradation of the bis-amide linkages in response to changes in pH values. PSIA-polyplexes were able to achieve efficient cellular uptake and luciferase gene silencing by co-transfection of pDNA and siRNA in COS-7 cells and HepG2 cells with negligible cytotoxicity. Biodistribution of Rhodamine B-labeled PSIA-polyplexes after being systemically injected in BALB/c nude-mice showed that the polyplexes circulated throughout the body, accumulated mainly in the kidney at 4 hours of sample administration, and moved to the liver and spleen after 24 hours. All the results suggested that PSIA offered a promising example to balance the transfection efficiency and toxicity of a synthetic carrier system for the delivery of therapeutic nucleic acids.Keywords: gene delivery, polyspermine, cytotoxicity, transfection efficiency, biodistribution

  18. Amides of non-steroidal anti-inflammatory drugs with thiomorpholine can yield hypolipidemic agents with improved anti-inflammatory activity.

    Theodosis-Nobelos, Panagiotis; Kourti, Malamati; Gavalas, Antonios; Rekka, Eleni A

    2016-02-01

    Novel amides of non steroidal anti-inflammatory drugs (NSAIDs), α-lipoic acid and indole-3-acetic acid with thiomorpholine were synthesised by a simple method and at high yields (60-92%). All the NSAID derivatives highly decreased lipidemic indices in the plasma of Triton treated hyperlipidemic rats. The most potent compound was the indomethacin derivative, which decreased total cholesterol, triglycerides and LDL cholesterol by 73%, 80% and 83%, respectively. They reduced acute inflammation equally or more than most parent acids. Hence, it could be concluded that amides of common NSAIDs with thiomorpholine acquire considerable hypolipidemic potency, while they preserve or augment their anti-inflammatory activity, thus addressing significant risk factors for atherogenesis. PMID:26750253

  19. A proton wire and water channel revealed in the crystal structure of isatin hydrolase

    Bjerregaard-Andersen, Kaare; Sommer, Theis; Jensen, Jan Kristian;

    2014-01-01

    The high resolution crystal structures of isatin hydrolase from Labrenzia aggregata in the apo and the product state, are described. These are the first structures of a functionally characterized metal-dependent hydrolase of this fold. Isatin hydrolase converts isatin to isatinate and belongs to a...... novel family of metalloenzymes that include the bacterial kynurenine formamidase. The product state, mimicked by bound thioisatinate, reveals a water molecule that bridges the thioisatinate to a proton wire in an adjacent water channel and thus allows the proton released by the reaction to escape only...

  20. Effect of phenobarbital on the level of translatable rat liver epoxide hydrolase mRNA.

    Pickett, C B; Lu, A Y

    1981-01-01

    Liver poly(A)+RNA isolated from untreated and phenobarbital-treated rats has been translated in the rabbit reticulocyte cell-fre system in order to determine the level of translationally active epoxide hydrolase (EC 3.3.2.3) mRNA. The in vitro translation systems were immunoprecipitated with rabbit IgG prepared against purified epoxide hydrolase, and the amount of epoxide hydrolase synthesized by the lysate programmed with control and phenobarbital poly(A)+RNA was quantitated. The level of tr...

  1. Part 1: Notch-sparing γ-secretase inhibitors: The identification of novel naphthyl and benzofuranyl amide analogs.

    Lu, Dai; Wei, Han-Xun; Zhang, Jing; Gu, Yongli; Osenkowski, Pamela; Ye, Wenjuan; Selkoe, Dennis J; Wolfe, Michael S; Augelli-Szafran, Corinne E

    2016-05-01

    γ-Secretase is one of two proteases directly involved in the production of the amyloid β-peptide (Aβ), which is pathogenic in Alzheimer's disease. Inhibition of γ-secretase to suppress the production of Aβ should not block processing of one of its alternative substrates, Notch1 receptors, as interference with Notch1 signaling leads to severe toxic effects. In the course of our studies to identify γ-secretase inhibitors with selectivity for APP over Notch, 1 [3-(benzyl(isopropyl)amino)-1-(naphthalen-2-yl)propan-1-one] was found to inhibit γ-secretase-mediated Aβ production without interfering with γ-secretase-mediated Notch processing in purified enzyme assays. As 1 is chemically unstable, efforts to increase the stability of this compound led to the identification of 2 [naphthalene-2-carboxylic acid benzyl-isopropyl-amide] which showed similar biological activity to compound 1. Synthesis and evaluation of a series of amide analogs resulted in benzofuranyl amide analogs that showed promising Notch-sparing γ-secretase inhibitory effects. This class of compounds may serve as a novel lead series for further study in the development of γ-secretase inhibitors. PMID:27013392

  2. Adsorption equilibrium of uranium from seawater on chelating resin containing amide oxime group

    Chelating resins containing amide oxime group were synthesized by radiation-induced graft polymerization. The amount of the amide oxime groups was controlled below about 0.1 mol per kg of base polymer. The adsorption equilibrium of uranium from seawater on this resin was investigated. It was suggested that two neighboring amide oxime groups on the grafted chain captured one uranyl ion, and that single amide oxime ligand had little capacity for the adsorption of uranium. The adsorption equilibrium was correlated by a Langmuir-type equation. The content of neighboring amide oxime groups was 0.406 x 10-3 mol per kg of base polymer, which corresponded to 0.39 % of the total amount of amide oxime groups. The apparent stoichiometric stability constant for the complex of uranyl ion with the neighboring amide oxime groups in seawater was calculated to be 10-21.7. (author)

  3. Cleavage of an amide bond by a ribozyme

    Dai, X.; De Mesmaeker, A.; Joyce, G. F.; Miller, S. L. (Principal Investigator)

    1995-01-01

    A variant form of a group I ribozyme, optimized by in vitro evolution for its ability to catalyze magnesium-dependent phosphoester transfer reactions involving DNA substrates, also catalyzes the cleavage of an unactivated alkyl amide when that linkage is presented in the context of an oligodeoxynucleotide analog. Substrates containing an amide bond that joins either two DNA oligos, or a DNA oligo and a short peptide, are cleaved in a magnesium-dependent fashion to generate the expected products. The first-order rate constant, kcat, is 0.1 x 10(-5) min-1 to 1 x 10(-5) min-1 for the DNA-flanked substrates, which corresponds to a rate acceleration of more than 10(3) as compared with the uncatalyzed reaction.

  4. Coumarin amide derivatives as fluorescence chemosensors for cyanide anions

    Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group have been synthesized. Their photophysical properties and recognition properties for cyanide anions have been examined. The results indicate that the compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change, at the same time, obvious color and fluorescence change can be observed by naked eye. The in situ hydrogen nuclear magnetic resonance spectra and photophysical properties change confirm that Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin. - Highlights: • Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group were synthesized. • The compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change. • Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin

  5. Bipolamides A and B, triene amides isolated from the endophytic fungus Bipolaris sp. MU34.

    Siriwach, Ratklao; Kinoshita, Hiroshi; Kitani, Shigeru; Igarashi, Yasuhiro; Pansuksan, Kanokthip; Panbangred, Watanalai; Nihira, Takuya

    2014-02-01

    As a result of the continued screening for new metabolites produced by endophytic fungi from Thai medicinal plants, two new triene fatty acid amides, bipolamides A (1) and B (2), were discovered from the endophytic fungus Bipolaris sp. MU34. The structures of all of the isolated compounds were elucidated on the basis of the spectroscopic data of NMR and MS. An antimicrobial assay revealed that bipolamide B (2) had moderate antifungal activity against Cladosporium cladosporioides FERMS-9, Cladosporium cucumerinum NBRC 6370, Saccharomyces cerevisiae ATCC 9804, Aspergillus niger ATCC 6275 and Rhisopus oryzae ATCC 10404, with Minimum inhibitory concentration (MIC) values of 16, 32, 32, 64 and 64 μg ml(-1), respectively. PMID:24192556

  6. Hydrolase stabilization via entanglement in poly(propylene sulfide) nanoparticles: stability towards reactive oxygen species.

    Allen, Brett L; Johnson, Jermaine D; Walker, Jeremy P

    2012-07-27

    In the advancement of green syntheses and sustainable reactions, enzymatic biocatalysis offers extremely high reaction rates and selectivity that goes far beyond the reach of chemical catalysts; however, these enzymes suffer from typical environmental constraints, e.g. operational temperature, pH and tolerance to oxidative environments. A common hydrolase enzyme, diisopropylfluorophosphatase (DFPase, EC 3.1.8.2), has demonstrated a pronounced efficacy for the hydrolysis of a variety of substrates for potential toxin remediation, but suffers from the aforementioned limitations. As a means to enhance DFPase's stability in oxidative environments, enzymatic covalent immobilization within the polymeric matrix of poly(propylene sulfide) (PPS) nanoparticles was performed. By modifying the enzyme's exposed lysine residues via thiolation, DFPase is utilized as a comonomer/crosslinker in a mild emulsion polymerization. The resultant polymeric polysulfide shell acts as a 'sacrificial barrier' by first oxidizing to polysulfoxides and polysulfones, rendering DFPase in an active state. DFPase-PPS nanoparticles thus retain activity upon exposure to as high as 50 parts per million (ppm) of hypochlorous acid (HOCl), while native DFPase is observed as inactive at 500 parts per billion (ppb). This trend is also confirmed by enzyme-generated (chloroperoxidase (CPO), EC 1.11.1.10) reactive oxygen species (ROS) including both HOCl (3 ppm) and ClO(2) (100 ppm). PMID:22743846

  7. Hydrolase stabilization via entanglement in poly(propylene sulfide) nanoparticles: stability towards reactive oxygen species

    In the advancement of green syntheses and sustainable reactions, enzymatic biocatalysis offers extremely high reaction rates and selectivity that goes far beyond the reach of chemical catalysts; however, these enzymes suffer from typical environmental constraints, e.g. operational temperature, pH and tolerance to oxidative environments. A common hydrolase enzyme, diisopropylfluorophosphatase (DFPase, EC 3.1.8.2), has demonstrated a pronounced efficacy for the hydrolysis of a variety of substrates for potential toxin remediation, but suffers from the aforementioned limitations. As a means to enhance DFPase’s stability in oxidative environments, enzymatic covalent immobilization within the polymeric matrix of poly(propylene sulfide) (PPS) nanoparticles was performed. By modifying the enzyme’s exposed lysine residues via thiolation, DFPase is utilized as a comonomer/crosslinker in a mild emulsion polymerization. The resultant polymeric polysulfide shell acts as a ‘sacrificial barrier’ by first oxidizing to polysulfoxides and polysulfones, rendering DFPase in an active state. DFPase–PPS nanoparticles thus retain activity upon exposure to as high as 50 parts per million (ppm) of hypochlorous acid (HOCl), while native DFPase is observed as inactive at 500 parts per billion (ppb). This trend is also confirmed by enzyme-generated (chloroperoxidase (CPO), EC 1.11.1.10) reactive oxygen species (ROS) including both HOCl (3 ppm) and ClO2 (100 ppm). (paper)

  8. Hydrolase stabilization via entanglement in poly(propylene sulfide) nanoparticles: stability towards reactive oxygen species

    Allen, Brett L.; Johnson, Jermaine D.; Walker, Jeremy P.

    2012-07-01

    In the advancement of green syntheses and sustainable reactions, enzymatic biocatalysis offers extremely high reaction rates and selectivity that goes far beyond the reach of chemical catalysts; however, these enzymes suffer from typical environmental constraints, e.g. operational temperature, pH and tolerance to oxidative environments. A common hydrolase enzyme, diisopropylfluorophosphatase (DFPase, EC 3.1.8.2), has demonstrated a pronounced efficacy for the hydrolysis of a variety of substrates for potential toxin remediation, but suffers from the aforementioned limitations. As a means to enhance DFPase’s stability in oxidative environments, enzymatic covalent immobilization within the polymeric matrix of poly(propylene sulfide) (PPS) nanoparticles was performed. By modifying the enzyme’s exposed lysine residues via thiolation, DFPase is utilized as a comonomer/crosslinker in a mild emulsion polymerization. The resultant polymeric polysulfide shell acts as a ‘sacrificial barrier’ by first oxidizing to polysulfoxides and polysulfones, rendering DFPase in an active state. DFPase-PPS nanoparticles thus retain activity upon exposure to as high as 50 parts per million (ppm) of hypochlorous acid (HOCl), while native DFPase is observed as inactive at 500 parts per billion (ppb). This trend is also confirmed by enzyme-generated (chloroperoxidase (CPO), EC 1.11.1.10) reactive oxygen species (ROS) including both HOCl (3 ppm) and ClO2 (100 ppm).

  9. Expression, Purification and Crystal Structure of a Truncated Acylpeptide Hydrolase from Aeropyrum pernix K1

    Hai-Feng ZHANG; Bai-Song ZHENG; Ying PENG; Zhi-Yong LOU; Yan FENG; Zi-He RAO

    2005-01-01

    Acylpeptide hydrolase (APH) catalyzes the N-terminal hydrolysis of Nα-acylpeptides to release Nα-acylated amino acids. The crystal structure of recombinant APH from the thermophilic archaeon Aeropyrum pernix K1 (apAPH) was reported recently to be at a resolution of 2.1 A using X-ray diffraction. A truncated mutant of apAPH that lacks the first short α-helix at the N-terminal, apAPH-△(1-21), was cloned, expressed,characterized and crystallized. Data from biochemical experiments indicate that the optimum temperature of apAPH is decreased by 15 ℃ with the deletion of the N-terminal α-helix. However, the enzyme activity at the optimal temperature does not change. It suggests that this N-terminal α-helix is essential for thermostability. Here, the crystal structure of apAPH-△(1-21) has been determined by molecular replacement to 2.5A. A comparison between the two structures suggests a difference in thermostability, and it can be concluded that by adding or deleting a linking structure (located over different domains), the stability or even the activity of an enzyme can be modified.

  10. Molecular and biochemical characterization of juvenile hormone epoxide hydrolase from the silkworm, Bombyx mori.

    Zhang, Qi-Rui; Xu, Wei-Hua; Chen, Fu-Sheng; Li, Sheng

    2005-02-01

    One major route of insect juvenile hormone (JH) degradation is epoxide hydration by JH epoxide hydrolase (JHEH). A full-length cDNA (1536 bp) encoding a microsomal JHEH was isolated from the silkworm, Bombyx mori. Bommo-JHEH cDNA contains an open reading frame encoding a 461-amino acid protein (52 kDa), which reveals a high degree of similarity to the previously reported insect JHEHs. The residues Tyr298, Tyr373, and the HGWP motif corresponding to the oxyanion hole of JHEHs and the residues Asp227, His430, and Glu403 in the catalytic triad are well conserved in Bommo-JHEH. Bommo-JHEH was highly expressed in the fat body, where its mRNA expression pattern was in contrast to the pattern of hemolymph levels of JH during the larval development, suggesting that Bommo-JHEH plays an important role in JH degradation. Recombinant Bommo-JHEH (52 kDa) expressed in Sf9 insect cells was membrane-bound and had a high level of enzyme activity (300-fold over the control activity). This Bommo-JHEH study provides a better understanding of how JH levels are regulated in the domesticated silkworm. PMID:15681225

  11. Bacillus thuringiensis peptidoglycan hydrolase SleB171 involved in daughter cell separation during cell division.

    Li, Hua; Hu, Penggao; Zhao, Xiuyun; Yu, Ziniu; Li, Lin

    2016-04-01

    Whole-genome analyses have revealed a putative cell wall hydrolase gene (sleB171) that constitutes an operon with two other genes (ypeBandyhcN) of unknown function inBacillus thuringiensisBMB171. The putative SleB171 protein consists of 259 amino acids and has a molecular weight of 28.3 kDa. Gene disruption ofsleB171in the BMB171 genome causes the formation of long cell chains during the vegetative growth phase and delays spore formation and spore release, although it has no significant effect on cell growth and the ultimate release of the spores. The inseparable vegetative cells were nearly restored through the complementation ofsleB171expression. Real-time quantitative polymerase chain reaction analysis revealed thatsleB171is mainly active in the vegetative growth phase, with a maximum activity at the early stationary growth phase. Western blot analysis also confirmed thatsleB171is preferentially expressed during the vegetative growth phase. These results demonstrated that SleB171 plays an essential role in the daughter cell separation during cell division. PMID:26922318

  12. Analysis of the key active subsites of glycoside hydrolase 13 family members.

    Kumar, Vikash

    2010-05-01

    alpha-Amylase, pullulanase, neopullulanase, cyclomaltodextrinase (CDase), cyclomaltodextin glucanotransferase (CGTase), etc. are some of the amylolytic enzymes that act on polysaccharides. These enzymes differ from each other with respect to substrate and linkage specificities. These enzymes have been grouped into the GH13 (GH, Glycoside Hydrolase) family in the CAZy database on the basis of similarity in amino acid sequence. Members of this family share three domains viz., A, B, and C, which have several binding subsites to accommodate monomeric units of the polysaccharide substrate. Among these subsites, -2, -1, +1, and +2 subsites are the most critical subsites for catalytic activity. In the present study, the substrate analog-, inhibitor-, or product-bound 3-D structures of 24 members of GH13 family have been analyzed to identify the features of the -2, -1, +1, and +2 subsites shared by all the members for recognition of the common substrate. It is found that neither the number nor the nature of the potential hydrogen bond-forming residues is conserved with the exception of the presence of tyrosine as a stacking residue in the -1 subsite. The relative spatial disposition of the conserved subsite residues are conserved as judged by distance matrices. The backbone of the -2, -1, +1, and +2 subsites does not undergo conformational change for the recognition of the substrate. This analysis suggests that these enzymes recognize their substrate on the basis of shape of the substrate rather than on the basis of specific interactions within the binding site. PMID:20227065

  13. Direct production of ethanol from neoagarobiose using recombinant yeast that secretes α-neoagarooligosaccharide hydrolase.

    Syazni; Yanagisawa, Mitsunori; Kasuu, Masahiro; Ariga, Osamu; Nakasaki, Kiyohiko

    2016-04-01

    An α-neoagarooligosaccharide hydrolase, AgaNash, was purified from Cellvibrio sp. OA-2007, which utilizes agarose as a substrate. The agaNash gene, which encodes AgaNash, was obtained by comparing the N-terminal amino acid sequence of AgaNash with that deduced from the nucleotide sequence of the full-length OA-2007 genome. The agaNash gene combined with the Saccharomyces cerevisiae signal peptide α-mating factor was transformed into the YPH499 strain of S. cerevisiae to generate YPH499/pTEF-MF-agaNash, and the recombinant yeast was confirmed to produce AgaNash, though it was mainly retained within the recombinant cell. To enhance AgaNash secretion from the cell, the signal peptide was replaced with a combination of the signal peptide and a threonine- and serine-rich tract (T-S region) of the S. diastaticus STA1 gene. The new recombinant yeast, YPH499/pTEF-STA1SP-agaNash, was demonstrated to secrete AgaNash and hydrolyze neoagarobiose with an efficiency of as high as 84%, thereby producing galactose, which is a fermentable sugar for the yeast, and ethanol, at concentrations of up to 1.8g/L, directly from neoagarobiose. PMID:26920485

  14. Discovery of Potent Soluble Epoxide Hydrolase (sEH) Inhibitors by Pharmacophore-Based Virtual Screening.

    Waltenberger, Birgit; Garscha, Ulrike; Temml, Veronika; Liers, Josephine; Werz, Oliver; Schuster, Daniela; Stuppner, Hermann

    2016-04-25

    There is an increasing interest in the development of soluble epoxide hydrolase (sEH) inhibitors, which block the degradation of endogenous anti-inflammatory epoxyeicosatrienoic acids. Within this study, a set of pharmacophore models for sEH inhibitors was developed. The Specs database was virtually screened and a cell-free sEH activity assay was used for the biological investigation of virtual hits. In total, out of 48 tested compounds, 19 were sEH inhibitors with IC50 < 10 μM, representing a prospective true positive hit rate of 40%. Six of these compounds displayed IC50 values in the low nanomolar range. The most potent compound 21, a urea derivative, inhibited sEH with an IC50 = 4.2 nM. The applied approach also enabled the identification of diverse chemical scaffolds, e.g. the pyrimidinone derivative 29 (IC50 = 277 nM). The generated pharmacophore model set therefore represents a valuable tool for the selection of compounds for biological testing. PMID:26882208

  15. Anti-Ulcer Efficacy of Soluble Epoxide Hydrolase Inhibitor TPPU on Diclofenac-Induced Intestinal Ulcers.

    Goswami, Sumanta Kumar; Wan, Debin; Yang, Jun; Trindade da Silva, Carlos A; Morisseau, Christophe; Kodani, Sean D; Yang, Guang-Yu; Inceoglu, Bora; Hammock, Bruce D

    2016-06-01

    Proton pump inhibitors such as omeprazole (OME) reduce the severity of gastrointestinal (GI) ulcers induced by nonsteroidal anti-inflammatory drugs (NSAIDs) but can also increase the chance of dysbiosis. The aim of this study was to test the hypothesis that preventive use of a soluble epoxide hydrolase inhibitor (sEHI) such as TPPU can decrease NSAID-induced ulcers by increasing anti-inflammatory epoxyeicosatrienoic acids (EETs). Dose- [10, 30, and 100 mg/kg, by mouth (PO)] and time-dependent (6 and 18 hours) ulcerative effects of diclofenac sodium (DCF, an NSAID) were studied in the small intestine of Swiss Webster mice. Dose-dependent effects of TPPU (0.001-0.1 mg/kg per day for 7 days, in drinking water) were evaluated in DCF-induced intestinal toxicity and compared with OME (20 mg/kg, PO). In addition, the effect of treatment was studied on levels of Hb in blood, EETs in plasma, inflammatory markers such as myeloperoxidase (MPO) in intestinal tissue homogenates, and tissue necrosis factor-α (TNF-α) in serum. DCF dose dependently induced ulcers that were associated with both a significant (P NSAID-induced ulcers. PMID:26989141

  16. Expression optimization and biochemical properties of two glycosyl hydrolase family 3 beta-glucosidases.

    Ma, Yuanyuan; Liu, Xuewei; Yin, Yanchen; Zou, Chao; Wang, Wanchao; Zou, Shaolan; Hong, Jiefang; Zhang, Minhua

    2015-07-20

    The β-glucosidases from Saccharomycopsis fibuligera (SfBGL1) and Trichoderma reesei (TrBGL1) were cloned and expressed in Pichia pastoris. Methanol concentration and pH significantly affected the production. The combined effects of the two factors were optimized by using the response surface method, resulting in a 137% and 84% increase in rTrBGL1 and rSfBGL1 yield compared to single-factor experiment. Structure and biochemical properties of the two enzyme were investigated and compared. They belong to glycosyl hydrolase family 3 and exhibit significant hydrolysis activity and low-level transglycosylation activity. The two enzymes show similar substrate affinity and ion-tolerance, and both of them can be activated by Cr(6+), Mn(2+) and Fe(2+). The rSfBGL1 has greater catalytic speed, higher specific activity and acid-tolerance than rTrBGL1, but rTrBGL1 is more thermostable and has higher optimal temperature than rSfBGL1. This study provides a useful and quick optimal method for recombinant enzyme production and makes a valuable comparison of biochemical properties, which opens important avenues of exploration for relationship between structure and function and further practical applications. PMID:25937452

  17. Purification and characterisation of a novel enantioselective epoxide hydrolase from Aspergillus niger M200

    Kotík, Michael; Kyslík, Pavel

    2006-01-01

    Roč. 1760, - (2006), s. 245-252. ISSN 0006-3002 Institutional research plan: CEZ:AV0Z50200510 Keywords : epoxide hydrolase * enantioselectivity * aspergillus niger Subject RIV: EE - Microbiology, Virology

  18. Total chemical synthesis of lassomycin and lassomycin-amide.

    Lear, S; Munshi, T; Hudson, A S; Hatton, C; Clardy, J; Mosely, J A; Bull, T J; Sit, C S; Cobb, S L

    2016-05-11

    Herein we report a practical synthetic route to the lasso peptide lassomycin () and C-terminal variant lassomycin-amide (). The biological evaluation of peptides and against Mycobacterium tuberculosis revealed that neither had any activity against this bacterium. This lack of biological activity has led us to propose that naturally occurring lassomycin may actually exhibit a standard lasso peptide threaded conformation rather than the previously reported unthreaded structure. PMID:27101411

  19. Spectroscopic properties of the nonplanar amide group: A computational study

    Bednárová, Lucie; Maloň, Petr; Bouř, Petr

    2007-01-01

    Roč. 19, č. 10 (2007), s. 775-786. ISSN 0899-0042 R&D Projects: GA ČR GA203/06/0420; GA ČR GA202/07/0732; GA AV ČR IAA400550702 Institutional research plan: CEZ:AV0Z40550506 Keywords : nonplanar amide bond * peptide geometry * proteins * circular dichroism Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.436, year: 2007

  20. Studies on Interactions between Sulfadiazine and Peptide Amides

    Wang Yiwei; Zhang Xiaoqin; Du Jun; Hua Song; Guo Jianmin

    2015-01-01

    In this study, the optimal structures and binding energies of 14 hydrogen bonded complexes, which contained the sulfadiazine, N-methylacetamide, a glycine dipeptide and an alanine dipeptide, were obtained. The sites preference of sulfadiazine hydrogen bonding to peptide amides were explored. The interaction energies of all the complexes were corrected by Basis Set Superposition Error (BSSE). By the analysis interaction energy, charge density and second-order interaction energies E(2) of the c...

  1. New 2{alpha}-tropane amides as potential PET ligands for the dopamine transporter

    Drewes, Birte [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany)]. E-mail: b.drewes@fz-juelich.de; Sihver, Wiebke [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Willbold, Sabine [Zentralabteilung fuer chemische Analysen, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Olsson, Ray A. [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Coenen, Heinz H. [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany)

    2007-07-15

    Positron emission tomography (PET) imaging of dopamine transporter (DAT) density in the brain is a potentially valuable tool for studying the etiopathology of degenerative brain disorders. The present study evaluated five new potential competitive inhibitors of DAT as ligands for PET. The evaluation of the new compounds measured their ability to compete with the binding of the reference ligand 2{beta}-carbomethoxy-3{beta}-(4-[{sup 131}I]iodophenyl)tropane [{sup 131}I]{beta}-CIT to striatal and cortical membranes from rat and pig brain. Four of the new compounds structurally related to cocaine were synthesized in their 2{alpha},3{beta} configuration; the most potent one, 3{beta}-(4-iodo-phenyl)-8-methyl-8-aza-bicyclo[3.2.1]octane-2{alpha}-carboxylic acid (2-fluoro-ethyl)-amide, was synthesized also in the 2{beta},3{beta} configuration. For comparative studies in rat brain and new evaluation in pig brain homogenate, the established compounds {beta}-CIT, FP-CIT, PE2I and FETT were also synthesized and evaluated. Contrary to expectation, the 2{alpha},3{beta} and 2{beta},3{beta} isomers of 3-(4-iodo-phenyl)-8-methyl-8-aza-bicyclo[3.2.1]octane-2-carboxylic acid (2-fluoro-ethyl)-amide showed the same affinity constant for rat striatum (K {sub i}=200 nM{+-}34), but in pig striatum and rat and pig cortex the 2{alpha},3{beta} form even had a higher affinity than the 2{beta},3{beta} form.

  2. Mild Metal-Free Hydrosilylation of Secondary Amides to Amines.

    Huang, Pei-Qiang; Lang, Qi-Wei; Wang, Yan-Rong

    2016-05-20

    The combination of amide activation by Tf2O with B(C6F5)3-catalyzed hydrosilylation with TMDS constitutes a method for the one-pot reduction of secondary amides to amines under mild conditions. The method displays a broad applicability for the reduction of many types of substrates, and shows good compatibility and excellent chemoselectivity for many sensitive functional groups. Reductions of a multifunctionalized α,β-unsaturated amide obtained from another synthetic methodology, and a C-H functionalization product produced the corresponding amines in good to excellent yield. Chemoselective reduction of enantiomeric pure (ee >99%) tetrahydro-5-oxo-2-furaneamides yielded 5-(aminomethyl)dihydrofuran-2(3H)-ones in a racemization-free manner. The latter were converted in one pot to N-protected 5-hydroxypiperidin-2-ones, which are building blocks for the synthesis of many natural products. Further elaboration of an intermediate led to a concise four-step synthesis of (-)-epi-pseudoconhydrine. PMID:27100232

  3. Purification and characterization of a secreted recombinant phosphotriesterase (parathion hydrolase) from Streptomyces lividans.

    Rowland, S S; Speedie, M K; Pogell, B M

    1991-01-01

    A heterologous phosphotriesterase (parathion hydrolase), previously cloned from a Flavobacterium species into Streptomyces lividans, was secreted at high levels and purified to homogeneity. N-terminal analysis revealed that it had been processed in the same manner as the native membrane-bound Flavobacterium hydrolase. The enzyme consisted of a single polypeptide with an apparent molecular weight of 35,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Substrate sp...

  4. HYDROLASING OF CONTAMINATED UNDERWATER BASIN SURFACES AT THE HANFORD K AREA

    This paper discusses selecting and implementing hydrolasing technology to reduce radioactive contamination in preparing to dispose of the K Basins; two highly contaminated concrete basins at the Hanford Site. A large collection of spent nuclear fuel stored for many years underwater at the K Basins has been removed to stable, dry, safe storage. Remediation activities have begun for the remaining highly contaminated water. sludge, and concrete basin structures. Hydrolasing will be used to decontaminate and prepare the basin structures for disposal

  5. IN VITRO SOLUBLE EPOXIDE HYDROLASE ENZYME INHIBITORY ACTIVITY OF SOME NOVEL CHALCONE DERIVATIVES

    Kuppusamy Asokkumar; Lokeswari Prathyusha Tangella; Muthusamy Umamaheshwari; Thirumalaisamy Shivashanmugam; Varadharajan Subhadradevi; Puliyath Jagannath; Arumugam Madeswaran

    2012-01-01

    Objective Soluble epoxide hydrolase (sEH) belongs to the α/β -hydrolase superfamily, a subclass of α/β proteins. Chalcones are chemical compounds that show hopeful obliging efficacy in controlling numerous diseases. The main objective of the study is to evaluate the sEH inhibitory activity of some synthesized chalcone derivatives and identification of its mode of inhibition. Methods Four different chalcone derivatives (PC-1 to PC-4) were selected for synthesis by Claisen-Schmidt method. The i...

  6. Structure-Guided Engineering of Molinate Hydrolase for the Degradation of Thiocarbamate Pesticides

    Leite, José P.; Duarte, Márcia; Paiva, Ana M.; Ferreira-da-Silva, Frederico; Matias, Pedro M.; Nunes, Olga C.; Gales, Luís

    2015-01-01

    Molinate is a recalcitrant thiocarbamate used to control grass weeds in rice fields. The recently described molinate hydrolase, from Gulosibacter molinativorax ON4T, plays a key role in the only known molinate degradation pathway ending in the formation of innocuous compounds. Here we report the crystal structure of recombinant molinate hydrolase at 2.27 Å. The structure reveals a homotetramer with a single mononuclear metal-dependent active site per monomer. The active site architecture show...

  7. Interactions between dietary oil treatments and genetic variants modulate fatty acid ethanolamides in plasma and body weight composition.

    Pu, Shuaihua; Eck, Peter; Jenkins, David J A; Connelly, Philip W; Lamarche, Benoît; Kris-Etherton, Penny M; West, Sheila G; Liu, Xiaoran; Jones, Peter J H

    2016-03-01

    Fatty acid ethanolamides (FAE), a group of lipid mediators derived from long-chain fatty acids (FA), mediate biological activities including activation of cannabinoid receptors, stimulation of fat oxidation and regulation of satiety. However, how circulating FAE levels are influenced by FA intake in humans remains unclear. The objective of the present study was to investigate the response of six major circulating FAE to various dietary oil treatments in a five-period, cross-over, randomised, double-blind, clinical study in volunteers with abdominal obesity. The treatment oils (60 g/12 552 kJ per d (60 g/3000 kcal per d)) provided for 30 d were as follows: conventional canola oil, high oleic canola oil, high oleic canola oil enriched with DHA, flax/safflower oil blend and corn/safflower oil blend. Two SNP associated with FAE degradation and synthesis were studied. Post-treatment results showed overall that plasma FAE levels were modulated by dietary FA and were positively correlated with corresponding plasma FA levels; minor allele (A) carriers of SNP rs324420 in gene fatty acid amide hydrolase produced higher circulating oleoylethanolamide (OEA) (P=0·0209) and docosahexaenoylethanolamide (DHEA) levels (P=0·0002). In addition, elevated plasma DHEA levels in response to DHA intake tended to be associated with lower plasma OEA levels and an increased gynoid fat mass. In summary, data suggest that the metabolic and physiological responses to dietary FA may be influenced via circulating FAE. Genetic analysis of rs324420 might help identify a sub-population that appears to benefit from increased consumption of DHA and oleic acid. PMID:26806592

  8. Direct Catalytic Asymmetric Mannich-Type Reaction of α- and β-Fluorinated Amides.

    Brewitz, Lennart; Arteaga, Fernando Arteaga; Yin, Liang; Alagiri, Kaliyamoorthy; Kumagai, Naoya; Shibasaki, Masakatsu

    2015-12-23

    The last two decades have witnessed the emergence of direct enolization protocols providing atom-economical and operationally simple methods to use enolates for stereoselective C-C bond-forming reactions, eliminating the inherent drawback of the preformation of enolates using stoichiometric amounts of reagents. In its infancy, direct enolization relied heavily on the intrinsic acidity of the latent enolates, and the reaction scope was limited to readily enolizable ketones and aldehydes. Recent advances in this field enabled the exploitation of carboxylic acid derivatives for direct enolization, offering expeditious access to synthetically versatile chiral building blocks. Despite the growing demand for enantioenriched fluorine-containing small molecules, α- and β-fluorinated carbonyl compounds have been neglected in direct enolization chemistry because of the competing and dominating defluorination pathway. Herein we present a comprehensive study on direct and highly stereoselective Mannich-type reactions of α- and β-fluorine-functionalized 7-azaindoline amides that rely on a soft Lewis acid/hard Brønsted base cooperative catalytic system to guarantee an efficient enolization while suppressing undesired defluorination. This protocol contributes to provide a series of fluorinated analogs of enantioenriched β-amino acids for medicinal chemistry. PMID:26652911

  9. A glycosyl hydrolase family 16 gene is responsible for the endogenous production of β-1,3-glucanases within decapod crustaceans.

    Linton, Stuart M; Cameron, Melissa S; Gray, Michael C; Donald, John A; Saborowski, Reinhard; von Bergen, Martin; Tomm, Janina M; Allardyce, Benjamin J

    2015-09-15

    To identify the gene responsible for the production of a β-1,3-glucanase (laminarinase) within crustacea, a glycosyl hydrolase family 16 (GHF16) gene was sequenced from the midgut glands of the gecarcinid land crab, Gecarcoidea natalis and the freshwater crayfish, Cherax destructor. An open reading frame of 1098 bp for G. natalis and 1095 bp for C. destructor was sequenced from cDNA. For G. natalis and C. destructor respectively, this encoded putative proteins of 365 and 364 amino acids with molecular masses of 41.4 and 41.5 kDa. mRNA for an identical GHF16 protein was also expressed in the haemolymph of C. destructor. These putative proteins contained binding and catalytic domains that are characteristic of a β-1,3-glucanase from glycosyl hydrolase family 16. The amino acid sequences of two short 8-9 amino acid residue peptides from a previously purified β-1,3-glucanase from G. natalis matched exactly that of the putative protein sequence. This plus the molecular masses of the putative proteins matching that of the purified proteins strongly suggests that the sequences obtained encode for a catalytically active β-1,3-glucanase. A glycosyl hydrolase family 16 cDNA was also partially sequenced from the midgut glands of other amphibious (Mictyris platycheles and Paragrapsus laevis) and terrestrial decapod species (Coenobita rugosus, Coenobita perlatus, Coenobita brevimanus and Birgus latro) to confirm that the gene is widely expressed within this group. There are three possible hypothesised functions and thus evolutionary routes for the β-1,3-glucanase: 1) a digestive enzyme which hydrolyses β-1,3-glucans, 2) an enzyme which cleaves β-1,3-glycosidic bonds within cell walls to release cell contents or 3) an immune protein which can hydrolyse the cell walls of potentially pathogenic micro-organisms. PMID:26024589

  10. Synergistic effects of three Piper amides on generalist and specialist herbivores.

    Dyer, L A; Dodson, C D; Stireman, J O; Tobler, M A; Smilanich, A M; Fincher, R M; Letourneau, D K

    2003-11-01

    The tropical rainforest shrub Piper cenocladum, which is normally defended against herbivores by a mutualistic ant, contains three amides that have various defensive functions. While the ants are effective primarily against specialist herbivores, we hypothesized that these secondary compounds would be effective against a wider range of insects, thus providing a broad array of defenses against herbivores. We also tested whether a mixture of amides would be more effective against herbivores than individual amides. Diets spiked with amides were offered to five herbivores: a naïve generalist caterpillar (Spodoptera frugiperda), two caterpillar species that are monophagous on P. cenocladum (Eois spp.), leaf-cutting ants (Atta cephalotes), and an omnivorous ant (Paraponera clavata). Amides had negative effects on all insects, whether they were naïve, experienced, generalized, or specialized feeders. For Spodoptera, amide mixtures caused decreased pupal weights and survivorship and increased development times. Eois pupal weights, larval mass gain, and development times were affected by additions of individual amides, but increased parasitism and lower survivorship were caused only by the amide mixture. Amide mixtures also deterred feeding by the two ant species, and crude plant extracts were strongly deterrent to P. clavata. The mixture of all three amides had the most dramatic deterrent and toxic effects across experiments, with the effects usually surpassing expected additive responses, indicating that these compounds can act synergistically against a wide array of herbivores. PMID:14682530

  11. Ab initio study of chemical bond interactions between covalently functionalized carbon nanotubes via amide, ester and anhydride linkages

    Ben Doudou, Bessem; Chen, Jun; Vivet, Alexandre; Poilâne, Christophe

    2016-03-01

    In this paper, we have investigated the chemical bond interactions between covalently functionalized zigzag (5,0) and (8,0) SWCNT-SWCNT via various covalent linkages. Side-to-side junctions connected via amide, ester and anhydride linkages were particularly studied. The geometries and energy of the forming reaction were investigated using first-principles density functional theory. Furthermore, the band structures and the total density of states (DOS) of the junctions have also been analyzed. Our results show that several promising structures could be obtained by using chemical connection strategy and particularly the junctions formed by coupling amino functionalized SWCNT and carboxylic acid functionalized SWCNT was more favorable.

  12. Thermodynamics of extraction of uranium(VI) and plutonium(IV) with some long-chain aliphatic amides

    Distribution data for U(VI) and Pu(IV) from 3.5 M nitric acid medium with 0.5 M N,N-dihexyl derivatives of hexanamide (DHHA), octanamide (DHOA) and decanamide (DHDA) in n-dodecane have been obtained in the temperature range 20-50 C. From these data, the enthalpy, entropy and free energy changes associated with their extraction reactions were evaluated by the temperature coefficient method. Results indicate that the extraction reactions of U(VI) and Pu(IV) with all the three amides are predominantly enthalpy stabilised. (orig.)

  13. Single-conformation infrared spectra of model peptides in the amide I and amide II regions: Experiment-based determination of local mode frequencies and inter-mode coupling

    Buchanan, Evan G.; James, William H.; Choi, Soo Hyuk; Guo, Li; Gellman, Samuel H.; Müller, Christian W.; Zwier, Timothy S.

    2012-09-01

    Single-conformation infrared spectra in the amide I and amide II regions have been recorded for a total of 34 conformations of three α-peptides, three β-peptides, four α/β-peptides, and one γ-peptide using resonant ion-dip infrared spectroscopy of the jet-cooled, isolated molecules. Assignments based on the amide NH stretch region were in hand, with the amide I/II data providing additional evidence in favor of the assignments. A set of 21 conformations that represent the full range of H-bonded structures were chosen to characterize the conformational dependence of the vibrational frequencies and infrared intensities of the local amide I and amide II modes and their amide I/I and amide II/II coupling constants. Scaled, harmonic calculations at the DFT M05-2X/6-31+G(d) level of theory accurately reproduce the experimental frequencies and infrared intensities in both the amide I and amide II regions. In the amide I region, Hessian reconstruction was used to extract local mode frequencies and amide I/I coupling constants for each conformation. These local amide I frequencies are in excellent agreement with those predicted by DFT calculations on the corresponding 13C = 18O isotopologues. In the amide II region, potential energy distribution analysis was combined with the Hessian reconstruction scheme to extract local amide II frequencies and amide II/II coupling constants. The agreement between these local amide II frequencies and those obtained from DFT calculations on the N-D isotopologues is slightly worse than for the corresponding comparison in the amide I region. The local mode frequencies in both regions are dictated by a combination of the direct H-bonding environment and indirect, "backside" H-bonds to the same amide group. More importantly, the sign and magnitude of the inter-amide coupling constants in both the amide I and amide II regions is shown to be characteristic of the size of the H-bonded ring linking the two amide groups. These amide I/I and

  14. Characterization and functional analysis of Trichinella spiralis Nudix hydrolase.

    Long, Shao Rong; Wang, Zhong Quan; Jiang, Peng; Liu, Ruo Dan; Qi, Xin; Liu, Pei; Ren, Hui Jun; Shi, Hai Ning; Cui, Jing

    2015-12-01

    Trichinella spiralis Nudix hydrolase (TsNd) was identified by screening a T7 phage display cDNA library from T. spiralis intestinal infective larvae (IIL), and vaccination of mice with recombinant TsNd protein (rTsNd) or TsNd DNA vaccine produced a partial protective immunity. The aim of this study was to identify the characteristics and biological functions of TsNd in the process of invasion and development of T. spiralis larvae. Transcription and expression of TsNd gene at all developmental stages of T. spiralis were observed by qPCR and immunofluorescent test (IFT). The rTsNd had the Nd enzymatic activity to dGTP, NAD, NADP and CoA. Its kinetic properties on the preferred substrate dGTP were calculated, and the Vmax, Km, and kcat/Km values at pH 8.0 were 3.19 μM min(-1) μg(-1), 370 μM, and 144 s(-1) M(-1), respectively, in reaction matrix containing 5 mM Zn(2+) and 2 mM DTT. The rTsNd was active from 25 °C to 50 °C, with optimal activity at 37 °C. rTsNd was able to bind specifically to mouse intestinal epithelial cells (IECs) and promoted the larval invasion of IECs, whereas anti-rTsNd antibodies inhibited the larval invasion of IECs in a dose-dependent manner. Anti-rTsNd antibodies could kill T. spiralis infective larvae by an ADCC-mediated mechanism. Our results showed that the rTsNd protein was able to interact with host IECs, had the Nudix hydrolasing activity and the enzymatic activity appeared to be essential indispensable for the T. spiralis larval invasion, development and survival in host. PMID:26545353

  15. Steric effects in release of amides from linkers in solid-phase synthesis. Molecular mechanics modeling of key step in peptide and combinatorial chemistry

    Norrby, Per-Ola; Jensen, Knud Jørgen

    2006-01-01

    Acidolytic release of an amide from a solid support by C-N bond cleavage is all ubiquitous and crucial step in many solid-phase syntheses. We have used molecular modeling of a pseudo-equilibrium to explore substituent and steric effects in the release of peptides. The high acid-lability of the...... the lability of a linkage. In addition, predictions indicated that steric effects from the C-alpha-substituent in a BAL anchored amino acid residue should accelerate the acidolytic release. The finding that steric crowding leads to increased acid-lability will be important for further development and...

  16. An efficient and convenient synthesis of N-substituted amides under heterogeneous condition using Al(HSO4)3 via Ritter reaction

    Elnaz Karimian; Batool Akhlaghinia; Sara S E Ghodsinia

    2016-03-01

    An efficient and inexpensive synthesis of N-substituted amides from the reaction of aliphatic and aromatic nitriles with various benzylic alcohols (secondary and tertiary) and tert-butyl alcohol by refluxing nitromethane via the Ritter reaction catalyzed by aluminum hydrogen sulfate [Al(HSO4)3] is described. Thecatalyst which is an air-stable, cost-effective solid acid could be readily recycled by filtration and reused four times without any significant loss of its activity.

  17. Preparation and release study of ibuprofen-loaded porous matrices of a biodegradable poly(ester amide) derived from L -alanine units

    Valle Mendoza, Luis Javier del; Roca, Diana; Franco García, María Lourdes; Puiggalí Bellalta, Jordi; Rodríguez Galán, Rafael Alfonso

    2011-01-01

    Scaffolds of a biodegradable poly(ester amide)constituted of L-alanine, sebacic acid, and 1,12-dodecanediol units (abbreviated as PADAS) were prepared by the compression-molding/particulate-leaching method. The influence of the type, size, and percentage of salt on the scaffold porosity and morphology was evaluated. The thermal behavior and crystallinity were also studied for samples obtained under different processing conditions. PADAS scaffolds were not cytotoxic because they showe...

  18. Soluble epoxide hydrolase deficiency ameliorates acute pancreatitis in mice.

    Bettaieb, Ahmed; Morisseau, Christophe; Hammock, Bruce; Haj, Fawaz

    2014-10-01

    Acute pancreatitis (AP) is a frequent gastrointestinal disorder that causes significant morbidity and its incidence has been progressively increasing. AP starts as a local inflammation in the pancreas that often leads to systemic inflammatory response and complications. Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose inhibition in murine models has beneficial effects in inflammatory diseases, but its significance in AP remains unexplored. To investigate whether sEH may have a causal role in AP we utilized sEH knockout (KO) mice to determine the effects of sEH deficiency on ceruelin- and arginine-induced AP. sEH expression increased at the protein and messenger RNA levels, as well as sEH activity in the early phase of cerulein- and arginine-induced AP in mice. In addition, amylase and lipase levels were lower in cerulein-treated sEH KO mice compared with non-treated controls. Moreover, pancreatic mRNA and serum concentrations of the inflammatory cytokines IL-1ß and IL-6 were lower in sEH KO mice compared with controls. Further, sEH KO mice exhibited decreased cerulein- and arginine-induced NF-?B inflammatory response, MAPKs activation and decreased cell death. These findings demonstrate a novel role for sEH in the progression of cerulein- and arginine-induced AP. PMID:26461340

  19. Ubiquitin C-Terminal Hydrolase L1 in Tumorigenesis

    Jennifer Hurst-Kennedy

    2012-01-01

    Full Text Available Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1, aka PGP9.5 is an abundant, neuronal deubiquitinating enzyme that has also been suggested to possess E3 ubiquitin-protein ligase activity and/or stabilize ubiquitin monomers in vivo. Recent evidence implicates dysregulation of UCH-L1 in the pathogenesis and progression of human cancers. Although typically only expressed in neurons, high levels of UCH-L1 have been found in many nonneuronal tumors, including breast, colorectal, and pancreatic carcinomas. UCH-L1 has also been implicated in the regulation of metastasis and cell growth during the progression of nonsmall cell lung carcinoma, colorectal cancer, and lymphoma. Together these studies suggest UCH-L1 has a potent oncogenic role and drives tumor development. Conversely, others have observed promoter methylation-mediated silencing of UCH-L1 in certain tumor subtypes, suggesting a potential tumor suppressor role for UCH-L1. In this paper, we provide an overview of the evidence supporting the involvement of UCH-L1 in tumor development and discuss the potential mechanisms of action of UCH-L1 in oncogenesis.

  20. Isolation and Total Synthesis of Stolonines A–C, Unique Taurine Amides from the Australian Marine Tunicate Cnemidocarpa stolonifera

    Trong D. Tran

    2015-07-01

    Full Text Available Cnemidocarpa stolonifera is an underexplored marine tunicate that only occurs on the tropical to subtropical East Coast of Australia, with only two pyridoacridine compounds reported previously. Qualitative analysis of the lead-like enhanced fractions of C. stolonifera by LC-MS dual electrospray ionization coupled with PDA and ELSD detectors led to the identification of three new natural products, stolonines A–C (1–3, belonging to the taurine amide structure class. Structures of the new compounds were determined by NMR and MS analyses and later verified by total synthesis. This is the first time that the conjugates of taurine with 3-indoleglyoxylic acid, quinoline-2-carboxylic acid and β-carboline-3-carboxylic acid present in stolonines A–C (1–3, respectively, have been reported. An immunofluorescence assay on PC3 cells indicated that compounds 1 and 3 increased cell size, induced mitochondrial texture elongation, and caused apoptosis in PC3 cells.

  1. Isolation and Total Synthesis of Stolonines A-C, Unique Taurine Amides from the Australian Marine Tunicate Cnemidocarpa stolonifera.

    Tran, Trong D; Pham, Ngoc B; Ekins, Merrick; Hooper, John N A; Quinn, Ronald J

    2015-07-01

    Cnemidocarpa stolonifera is an underexplored marine tunicate that only occurs on the tropical to subtropical East Coast of Australia, with only two pyridoacridine compounds reported previously. Qualitative analysis of the lead-like enhanced fractions of C. stolonifera by LC-MS dual electrospray ionization coupled with PDA and ELSD detectors led to the identification of three new natural products, stolonines A-C (1-3), belonging to the taurine amide structure class. Structures of the new compounds were determined by NMR and MS analyses and later verified by total synthesis. This is the first time that the conjugates of taurine with 3-indoleglyoxylic acid, quinoline-2-carboxylic acid and β-carboline-3-carboxylic acid present in stolonines A-C (1-3), respectively, have been reported. An immunofluorescence assay on PC3 cells indicated that compounds 1 and 3 increased cell size, induced mitochondrial texture elongation, and caused apoptosis in PC3 cells. PMID:26204949

  2. Synthesis of Imidates: TFA-Mediated Regioselective Amide Alkylation Using Meerwein's Reagent.

    Popov, Kirill; Somfai, Peter

    2016-04-15

    Regioselective O-alkylation of an amide to form the corresponding imidate is a common synthetic problem, often resulting in varying amounts of N-alkylation. Screening existing methods for converting amides to imidates gave inconsistent or irreproducible results, sometimes affording N-alkylamide as the major product. A simple and reliable protocol for amide O-alkylation with complete regioselectivity has been designed, and its scope and efficiency demonstrated on a number of substrates. PMID:27019206

  3. Recent advances in copper-catalyzed C-H bond amidation.

    Wan, Jie-Ping; Jing, Yanfeng

    2015-01-01

    Copper catalysis has been known as a powerful tool for its ubiquitous application in organic synthesis. One of the fundamental utilities of copper catalysis is in the C-N bond formation by using carbon sources and nitrogen functional groups such as amides. In this review, the recent progress in the amidation reactions employing copper-catalyzed C-H amidation is summarized. PMID:26664644

  4. Discovery of triterpenoids as reversible inhibitors of α/β-hydrolase domain containing 12 (ABHD12.

    Teija Parkkari

    Full Text Available BACKGROUND: α/β-Hydrolase domain containing (ABHD12 is a recently discovered serine hydrolase that acts in vivo as a lysophospholipase for lysophosphatidylserine. Dysfunctional ABHD12 has been linked to the rare neurodegenerative disorder called PHARC (polyneuropathy, hearing loss, ataxia, retinosis pigmentosa, cataract. In vitro, ABHD12 has been implicated in the metabolism of the endocannabinoid 2-arachidonoylglycerol (2-AG. Further studies on ABHD12 function are hampered as no selective inhibitor have been identified to date. In contrast to the situation with the other endocannabinoid hydrolases, ABHD12 has remained a challenging target for inhibitor development as no crystal structures are available to facilitate drug design. METHODOLOGY/PRINCIPAL FINDINGS: Here we report the unexpected discovery that certain triterpene-based structures inhibit human ABHD12 hydrolase activity in a reversible manner, the best compounds showing submicromolar potency. Based on structure activity relationship (SAR data collected for 68 natural and synthetic triterpenoid structures, a pharmacophore model has been constructed. A pentacyclic triterpene backbone with carboxyl group at position 17, small hydrophobic substituent at the position 4, hydrogen bond donor or acceptor at position 3 accompanied with four axial methyl substituents was found crucial for ABHD12 inhibitor activity. Although the triterpenoids typically may have multiple protein targets, we witnessed unprecedented selectivity for ABHD12 among the metabolic serine hydrolases, as activity-based protein profiling of mouse brain membrane proteome indicated that the representative ABHD12 inhibitors did not inhibit other serine hydrolases, nor did they target cannabinoid receptors. CONCLUSIONS/SIGNIFICANCE: We have identified reversibly-acting triterpene-based inhibitors that show remarkable selectivity for ABHD12 over other metabolic serine hydrolases. Based on SAR data, we have constructed the first

  5. Discovery of Triterpenoids as Reversible Inhibitors of α/β-hydrolase Domain Containing 12 (ABHD12)

    Parkkari, Teija; Haavikko, Raisa; Laitinen, Tuomo; Navia-Paldanius, Dina; Rytilahti, Roosa; Vaara, Miia; Lehtonen, Marko; Alakurtti, Sami; Yli-Kauhaluoma, Jari; Nevalainen, Tapio; Savinainen, Juha R.; Laitinen, Jarmo T.

    2014-01-01

    Background α/β-hydrolase domain containing (ABHD)12 is a recently discovered serine hydrolase that acts in vivo as a lysophospholipase for lysophosphatidylserine. Dysfunctional ABHD12 has been linked to the rare neurodegenerative disorder called PHARC (polyneuropathy, hearing loss, ataxia, retinosis pigmentosa, cataract). In vitro, ABHD12 has been implicated in the metabolism of the endocannabinoid 2-arachidonoylglycerol (2-AG). Further studies on ABHD12 function are hampered as no selective inhibitor have been identified to date. In contrast to the situation with the other endocannabinoid hydrolases, ABHD12 has remained a challenging target for inhibitor development as no crystal structures are available to facilitate drug design. Methodology/Principal Findings Here we report the unexpected discovery that certain triterpene-based structures inhibit human ABHD12 hydrolase activity in a reversible manner, the best compounds showing submicromolar potency. Based on structure activity relationship (SAR) data collected for 68 natural and synthetic triterpenoid structures, a pharmacophore model has been constructed. A pentacyclic triterpene backbone with carboxyl group at position 17, small hydrophobic substituent at the position 4, hydrogen bond donor or acceptor at position 3 accompanied with four axial methyl substituents was found crucial for ABHD12 inhibitor activity. Although the triterpenoids typically may have multiple protein targets, we witnessed unprecedented selectivity for ABHD12 among the metabolic serine hydrolases, as activity-based protein profiling of mouse brain membrane proteome indicated that the representative ABHD12 inhibitors did not inhibit other serine hydrolases, nor did they target cannabinoid receptors. Conclusions/Significance We have identified reversibly-acting triterpene-based inhibitors that show remarkable selectivity for ABHD12 over other metabolic serine hydrolases. Based on SAR data, we have constructed the first pharmacophore

  6. Evaluation of the Ser-His Dipeptide, a Putative Catalyst of Amide and Ester Hydrolysis.

    MacDonald, Melissa J; Lavis, Luke D; Hilvert, Donald; Gellman, Samuel H

    2016-08-01

    Efficient hydrolysis of amide bonds has long been a reaction of interest for organic chemists. The rate constants of proteases are unmatched by those of any synthetic catalyst. It has been proposed that a dipeptide containing serine and histidine is an effective catalyst of amide hydrolysis, based on an apparent ability to degrade a protein. The capacity of the Ser-His dipeptide to catalyze the hydrolysis of several discrete ester and amide substrates is investigated using previously described conditions. This dipeptide does not catalyze the hydrolysis of amide or unactivated ester groups in any of the substrates under the conditions evaluated. PMID:27400366

  7. Examination of the Addictive and Behavioral Properties of Fatty Acid-Binding Protein Inhibitor SBFI26

    Thanos, Panayotis K.; Clavin, Brendan H.; Hamilton, John; O’Rourke, Joseph R.; Maher, Thomas; Koumas, Christopher; Miao, Erick; Lankop, Jessenia; Elhage, Aya; Haj-Dahmane, Samir; Deutsch, Dale; Kaczocha, Martin

    2016-01-01

    The therapeutic properties of cannabinoids have been well demonstrated but are overshadowed by such adverse effects as cognitive and motor dysfunction, as well as their potential for addiction. Recent research on the natural lipid ligands of cannabinoid receptors, also known as endocannabinoids, has shed light on the mechanisms of intracellular transport of the endocannabinoid anandamide by fatty acid-binding proteins (FABPs) and subsequent catabolism by fatty acid amide hydrolase. These findings facilitated the recent development of SBFI26, a pharmacological inhibitor of epidermal- and brain-specific FABP5 and FABP7, which effectively increases anandamide signaling. The goal of this study was to examine this compound for any possible rewarding and addictive properties as well as effects on locomotor activity, working/recognition memory, and propensity for sociability and preference for social novelty (SN) given its recently reported anti-inflammatory and analgesic properties. Male C57BL mice were split into four treatment groups and conditioned with 5.0, 20.0, 40.0 mg/kg SBFI26, or vehicle during a conditioned place preference (CPP) paradigm. Following CPP, mice underwent a battery of behavioral tests [open field, novel object recognition (NOR), social interaction (SI), and SN] paired with acute SBFI26 administration. Results showed that SBFI26 did not produce CPP or conditioned place aversion regardless of dose and did not induce any differences in locomotor and exploratory activity during CPP- or SBFI26-paired open field activity. We also observed no differences between treatment groups in NOR, SI, and SN. In conclusion, as SBFI26 was shown previously by our group to have significant analgesic and anti-inflammatory properties, here we show that it does not pose a risk of dependence or motor and cognitive impairment under the conditions tested. PMID:27092087

  8. Examination of the Addictive and Behavioral Properties of Fatty Acid-Binding Protein Inhibitor SBFI26.

    Thanos, Panayotis K; Clavin, Brendan H; Hamilton, John; O'Rourke, Joseph R; Maher, Thomas; Koumas, Christopher; Miao, Erick; Lankop, Jessenia; Elhage, Aya; Haj-Dahmane, Samir; Deutsch, Dale; Kaczocha, Martin

    2016-01-01

    The therapeutic properties of cannabinoids have been well demonstrated but are overshadowed by such adverse effects as cognitive and motor dysfunction, as well as their potential for addiction. Recent research on the natural lipid ligands of cannabinoid receptors, also known as endocannabinoids, has shed light on the mechanisms of intracellular transport of the endocannabinoid anandamide by fatty acid-binding proteins (FABPs) and subsequent catabolism by fatty acid amide hydrolase. These findings facilitated the recent development of SBFI26, a pharmacological inhibitor of epidermal- and brain-specific FABP5 and FABP7, which effectively increases anandamide signaling. The goal of this study was to examine this compound for any possible rewarding and addictive properties as well as effects on locomotor activity, working/recognition memory, and propensity for sociability and preference for social novelty (SN) given its recently reported anti-inflammatory and analgesic properties. Male C57BL mice were split into four treatment groups and conditioned with 5.0, 20.0, 40.0 mg/kg SBFI26, or vehicle during a conditioned place preference (CPP) paradigm. Following CPP, mice underwent a battery of behavioral tests [open field, novel object recognition (NOR), social interaction (SI), and SN] paired with acute SBFI26 administration. Results showed that SBFI26 did not produce CPP or conditioned place aversion regardless of dose and did not induce any differences in locomotor and exploratory activity during CPP- or SBFI26-paired open field activity. We also observed no differences between treatment groups in NOR, SI, and SN. In conclusion, as SBFI26 was shown previously by our group to have significant analgesic and anti-inflammatory properties, here we show that it does not pose a risk of dependence or motor and cognitive impairment under the conditions tested. PMID:27092087

  9. Three new amides from streptomyces sp. H7372

    Three new amides, methyl phenatate A (1), actiphenamide (2) and actiphenol 1-beta-D-glucopyranoside (3), along with thirteen known compounds, were isolated from the organic extract of a fermentation culture of Streptomyces sp. H7372. The structures were elucidated by spectroscopic methods including 1D- and 2D-NMR techniques, and MS analyses. Cycloheximide (6) and cyclo(ΔAla-L-Val) (8) gave a clear zone of inhibition of Ras-Raf-1 interaction in the yeast two hybrid assay which showed high potency with 10 and 25 mm clear ZOIs on SD His- and inactive on SD His+ at 2.5 mug per disk, respectively. (author)

  10. Two new chlorinated amides from Nicotiana glauca R. Graham.

    Backheet, E Y; Sayed, H M

    2002-03-01

    Two new chlorinated amides, N-(2',6'-diethyl phenyl)-2-chloroacetamide (1) and N-(butyloxymethyl)-N-(2',6'-diethyl phenyl)-2-chloroacetamide (2) were isolated for the first time from the ethanolic extract of the leaves of Nicotiana glauca R. Graham in addition to triacontanol (3), scopoletin (4) and stigmasterol-3-beta-O-D-gluco-pyranoside (5). The structures of the isolated compounds were elucidated by spectroscopic analysis (1D, 2D NMR, EIMS, HR-EIMS, IR and UV). PMID:11933854

  11. Chemical Modifications of Hyaluronan using DMTMM-Activated Amidation

    Rydergren, Sara

    2013-01-01

    An alternative approach to chemically modifying hyaluronan (HA) has been investigated. The triazine derivative 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMTMM) has been used to activate carboxylic groups on HA, which react further to form stable amide bonds with primary and secondary amines. The reaction can either be used to couple monoamines to HA or to produce hydrogels by using diamines that form crosslinks between the HA chains. The reaction between HA and DMTMM has been...

  12. Antifungal activity of natural and synthetic amides from Piper species

    The antifungal leaves extract from Piper scutifolium was submitted to bioactivity-guided chromatographic separation against Cladosporium cladosporioides and C. sphaerospermum yielding piperine, piperlonguminine and corcovadine as the active principles which displayed a detection limit of 1 μg. Structure-activity relationships were investigated with the preparation of twelve analogs having differences in the number of unsaturations, aromatic ring substituents and in the amide moiety. Analogs having a single double-bond and no substituent in the aromatic ring displayed higher activity, while N,N,-diethyl analogs displayed higher dose-dependent activity. (author)

  13. Antifungal activity of natural and synthetic amides from Piper species

    Marques, Joaquim V.; Oliveira, Alberto de; Kato, Massuo J., E-mail: majokato@iq.usp.b [Universidade de Sao Paulo (IQ/USP), SP (Brazil). Inst. de Quimica; Raggi, Ludmila; Young, Maria C. [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Fisiologia e Bioquimica de Plantas

    2010-07-01

    The antifungal leaves extract from Piper scutifolium was submitted to bioactivity-guided chromatographic separation against Cladosporium cladosporioides and C. sphaerospermum yielding piperine, piperlonguminine and corcovadine as the active principles which displayed a detection limit of 1 {mu}g. Structure-activity relationships were investigated with the preparation of twelve analogs having differences in the number of unsaturations, aromatic ring substituents and in the amide moiety. Analogs having a single double-bond and no substituent in the aromatic ring displayed higher activity, while N,N,-diethyl analogs displayed higher dose-dependent activity. (author)

  14. A remote but significant sequence homology between glycoside hydrolase clan GH-H and glycoside hydrolase family GH 31

    Janecek, S.; Svensson, Birte; MacGregor, E.A.

    2007-01-01

    Although both the α-amylase super-family, i.e. the glycoside hydrolase (GH) clan GH-H (the GH families 13, 70 and 77), and family GH31 share some characteristics, their different catalytic machinery prevents classification of GH31 in clan GH-H. A significant but remote evolutionary relatedness is......, however, proposed for clan GH-H with GH31. A sequence alignment, based on the idea that residues equivalent in the primordial catalytic GH-H/GH31 (β/α)8-barrel may not be found in the present-day GH-H and GH31 structures at strictly equivalent positions, shows remote sequence homologies covering β3, β4, β......7 and β8 of the GH-H and GH31 (β/α)8-barrels. Structure comparison of GH13 α-amylase and GH31 α-xylosidase guided alignment of GH-H and GH31 members for construction of evolutionary trees. The closest sequence relationship displayed by GH31 is to GH77 of clan GH-H....

  15. Recruitment of Glycosyl Hydrolase Proteins in a Cone Snail Venomous Arsenal: Further Insights into Biomolecular Features of Conus Venoms

    Philippe Favreau

    2012-01-01

    Full Text Available Cone snail venoms are considered an untapped reservoir of extremely diverse peptides, named conopeptides, displaying a wide array of pharmacological activities. We report here for the first time, the presence of high molecular weight compounds that participate in the envenomation cocktail used by these marine snails. Using a combination of proteomic and transcriptomic approaches, we identified glycosyl hydrolase proteins, of the hyaluronidase type (Hyal, from the dissected and injectable venoms (“injectable venom” stands for the venom variety obtained by milking of the snails. This is in contrast to the “dissected venom”, which was obtained from dissected snails by extraction of the venom glands of a fish-hunting cone snail, Conus consors (Pionoconus clade. The major Hyal isoform, Conohyal-Cn1, is expressed as a mixture of numerous glycosylated proteins in the 50 kDa molecular mass range, as observed in 2D gel and mass spectrometry analyses. Further proteomic analysis and venom duct mRNA sequencing allowed full sequence determination. Additionally, unambiguous segment location of at least three glycosylation sites could be determined, with glycans corresponding to multiple hexose (Hex and N-acetylhexosamine (HexNAc moieties. With respect to other known Hyals, Conohyal-Cn1 clearly belongs to the hydrolase-type of Hyals, with strictly conserved consensus catalytic donor and positioning residues. Potent biological activity of the native Conohyals could be confirmed in degrading hyaluronic acid. A similar Hyal sequence was also found in the venom duct transcriptome of C. adamsonii (Textilia clade, implying a possible widespread recruitment of this enzyme family in fish-hunting cone snail venoms. These results provide the first detailed Hyal sequence characterized from a cone snail venom, and to a larger extent in the Mollusca phylum, thus extending our knowledge on this protein family and its evolutionary selection in marine snail venoms.

  16. 嗜酸糖苷水解酶研究进展%Research Progress on Acidophilic Glycoside Hydrolase

    罗会颖; 姚斌; 范云六

    2013-01-01

    随着极端微生物及极端酶的广泛研究,嗜酸酶因其在极端酸性环境中具有高的酶活性和稳定性而倍受关注,并取得了较大的研究进展。嗜酸糖苷水解酶是嗜酸酶中最重要的一类,在生物能源、饲料、食品等工业中具有重要的应用前景。综述了重要嗜酸糖苷水解酶,包括嗜酸淀粉酶、嗜酸纤维素酶、嗜酸木聚糖酶和甘露聚糖酶在基因的挖掘、表达、分子改良嗜酸机制研究以及应用等方面国内外的研究进展,展望了嗜酸糖苷水解酶未来可能的研究方向和发展前景。%Extremophiles and enzymes from extremophiles are widely studied. Of them, acidophilic enzyme attracts much attention, due to its high activity and stability under extreme acidic conditions, and this research has made rapid progress. Acidophilic glycosyl hydrolase is one of the most important acidophilic enzymes, and has significant application prospect in bio-energy, animal feed, food and other industries. This paper reviewed the gene cloning, heterologous expression, molecular modification and acidophilic mechanisms of important acidophilic glycosyl hydrolases, including amylase, cellulase, xylanase, and mannanase. The research orientation and development prospects were also elucidated in this paper.

  17. Carbonyl sulfide hydrolase from Thiobacillus thioparus strain THI115 is one of the β-carbonic anhydrase family enzymes.

    Ogawa, Takahiro; Noguchi, Keiichi; Saito, Masahiko; Nagahata, Yoshiko; Kato, Hiromi; Ohtaki, Akashi; Nakayama, Hiroshi; Dohmae, Naoshi; Matsushita, Yasuhiko; Odaka, Masafumi; Yohda, Masafumi; Nyunoya, Hiroshi; Katayama, Yoko

    2013-03-13

    Carbonyl sulfide (COS) is an atmospheric trace gas leading to sulfate aerosol formation, thereby participating in the global radiation balance and ozone chemistry, but its biological sinks are not well understood. Thiobacillus thioparus strain THI115 can grow on thiocyanate (SCN(-)) as its sole energy source. Previously, we showed that SCN(-) is first converted to COS by thiocyanate hydrolase in T. thioparus strain THI115. In the present work, we purified, characterized, and determined the crystal structure of carbonyl sulfide hydrolase (COSase), which is responsible for the degradation of COS to H2S and CO2, the second step of SCN(-) assimilation. COSase is a homotetramer composed of a 23.4 kDa subunit containing a zinc ion in its catalytic site. The amino acid sequence of COSase is homologous to the β-class carbonic anhydrases (β-CAs). Although the crystal structure including the catalytic site resembles those of the β-CAs, CO2 hydration activity of COSase is negligible compared to those of the β-CAs. The α5 helix and the extra loop (Gly150-Pro158) near the N-terminus of the α6 helix narrow the substrate pathway, which could be responsible for the substrate specificity. The k(cat)/K(m) value, 9.6 × 10(5) s(-1) M(-1), is comparable to those of the β-CAs. COSase hydrolyzes COS over a wide concentration range, including the ambient level, in vitro and in vivo. COSase and its structurally related enzymes are distributed in the clade D in the phylogenetic tree of β-CAs, suggesting that COSase and its related enzymes are one of the catalysts responsible for the global sink of COS. PMID:23406161

  18. Long-acting cocaine hydrolase for addiction therapy.

    Chen, Xiabin; Xue, Liu; Hou, Shurong; Jin, Zhenyu; Zhang, Ting; Zheng, Fang; Zhan, Chang-Guo

    2016-01-12

    Cocaine abuse is a world-wide public health and social problem without a US Food and Drug Administration-approved medication. An ideal anticocaine medication would accelerate cocaine metabolism, producing biologically inactive metabolites by administration of an efficient cocaine-specific exogenous enzyme. Our recent studies have led to the discovery of the desirable, highly efficient cocaine hydrolases (CocHs) that can efficiently detoxify and inactivate cocaine without affecting normal functions of the CNS. Preclinical and clinical data have demonstrated that these CocHs are safe for use in humans and are effective for accelerating cocaine metabolism. However, the actual therapeutic use of a CocH in cocaine addiction treatment is limited by its short biological half-life (e.g., 8 h or shorter in rats). Here we demonstrate a novel CocH form, a catalytic antibody analog, which is a fragment crystallizable (Fc)-fused CocH dimer (CocH-Fc) constructed by using CocH to replace the Fab region of human IgG1. The CocH-Fc not only has a high catalytic efficiency against cocaine but also, like an antibody, has a considerably longer biological half-life (e.g., ∼107 h in rats). A single dose of CocH-Fc was able to accelerate cocaine metabolism in rats even after 20 d and thus block cocaine-induced hyperactivity and toxicity for a long period. Given the general observation that the biological half-life of a protein drug is significantly longer in humans than in rodents, the CocH-Fc reported in this study could allow dosing once every 2-4 wk, or longer, for treatment of cocaine addiction in humans. PMID:26712009

  19. PREPARATION AND CHARACTERIZATION OF AMIDATED PECTIN BASED POLYMER ELECTROLYTE MEMBRANES

    R.K.Mishra; A.Anis; S.Mondal; M.Dutt; A.K.Banthia

    2009-01-01

    The work presents the synthesis and characterization of ami dated pectin(AP)based polymer electrolyte membranes(PEM)crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA)and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(YM and YN)are calculated based on the results of organic elemental analysis.FTIR spectroscopy indicated the presence of primary and secondary amide absorption bands.XRD pattern of membranes clearly indicates that there is a considerable increase in crystallinity as compared to parent pectin.TGA studies indicate that AP is less thermally stable than reference pectin.A maximum room temperature conductivity of 1.098×10-3 Scm-1 is obtained in the membrane,which is designated as AP-3.These properties make them good candidates for low cost biopolymer electrolyte membranes for fuel cell applications.

  20. Gene deficiency and pharmacological inhibition of soluble epoxide hydrolase confers resilience to repeated social defeat stress

    Ren, Qian; Ma, Min; Ishima, Tamaki; Morisseau, Christophe; Yang, Jun; Wagner, Karen M.; Zhang, Ji-chun; Yang, Chun; Yao, Wei; Dong, Chao; Han, Mei; Hammock, Bruce D.; Hashimoto, Kenji

    2016-01-01

    Depression is a severe and chronic psychiatric disease, affecting 350 million subjects worldwide. Although multiple antidepressants have been used in the treatment of depressive symptoms, their beneficial effects are limited. The soluble epoxide hydrolase (sEH) plays a key role in the inflammation that is involved in depression. Thus, we examined here the role of sEH in depression. In both inflammation and social defeat stress models of depression, a potent sEH inhibitor, TPPU, displayed rapid antidepressant effects. Expression of sEH protein in the brain from chronically stressed (susceptible) mice was higher than of control mice. Furthermore, expression of sEH protein in postmortem brain samples of patients with psychiatric diseases, including depression, bipolar disorder, and schizophrenia, was higher than controls. This finding suggests that increased sEH levels might be involved in the pathogenesis of certain psychiatric diseases. In support of this hypothesis, pretreatment with TPPU prevented the onset of depression-like behaviors after inflammation or repeated social defeat stress. Moreover, sEH KO mice did not show depression-like behavior after repeated social defeat stress, suggesting stress resilience. The sEH KO mice showed increased brain-derived neurotrophic factor (BDNF) and phosphorylation of its receptor TrkB in the prefrontal cortex, hippocampus, but not nucleus accumbens, suggesting that increased BDNF-TrkB signaling in the prefrontal cortex and hippocampus confer stress resilience. All of these findings suggest that sEH plays a key role in the pathophysiology of depression, and that epoxy fatty acids, their mimics, as well as sEH inhibitors could be potential therapeutic or prophylactic drugs for depression. PMID:26976569

  1. Gene deficiency and pharmacological inhibition of soluble epoxide hydrolase confers resilience to repeated social defeat stress.

    Ren, Qian; Ma, Min; Ishima, Tamaki; Morisseau, Christophe; Yang, Jun; Wagner, Karen M; Zhang, Ji-Chun; Yang, Chun; Yao, Wei; Dong, Chao; Han, Mei; Hammock, Bruce D; Hashimoto, Kenji

    2016-03-29

    Depression is a severe and chronic psychiatric disease, affecting 350 million subjects worldwide. Although multiple antidepressants have been used in the treatment of depressive symptoms, their beneficial effects are limited. The soluble epoxide hydrolase (sEH) plays a key role in the inflammation that is involved in depression. Thus, we examined here the role of sEH in depression. In both inflammation and social defeat stress models of depression, a potent sEH inhibitor, TPPU, displayed rapid antidepressant effects. Expression of sEH protein in the brain from chronically stressed (susceptible) mice was higher than of control mice. Furthermore, expression of sEH protein in postmortem brain samples of patients with psychiatric diseases, including depression, bipolar disorder, and schizophrenia, was higher than controls. This finding suggests that increased sEH levels might be involved in the pathogenesis of certain psychiatric diseases. In support of this hypothesis, pretreatment with TPPU prevented the onset of depression-like behaviors after inflammation or repeated social defeat stress. Moreover, sEH KO mice did not show depression-like behavior after repeated social defeat stress, suggesting stress resilience. The sEH KO mice showed increased brain-derived neurotrophic factor (BDNF) and phosphorylation of its receptor TrkB in the prefrontal cortex, hippocampus, but not nucleus accumbens, suggesting that increased BDNF-TrkB signaling in the prefrontal cortex and hippocampus confer stress resilience. All of these findings suggest that sEH plays a key role in the pathophysiology of depression, and that epoxy fatty acids, their mimics, as well as sEH inhibitors could be potential therapeutic or prophylactic drugs for depression. PMID:26976569

  2. Two enzymes which catalyze the amidation of peptide C-terminals are synthesized by a single mRNA. Peptide C mattan amid ka hanno wo shokubaisuru futatsu no koso wa ippon no mRNA yori goseisareru

    Kato, I.; Yonekura, H.; Okamoto, H. (Tohoku Univ., Sendai (Japan))

    1991-10-25

    Recent findings by the authors are reviewed on the amidation that forms amid structure essential to physiological activities in C-terminals of peptide hormones such as oxytocin,VIP,PP. It is noted that the amidation had been considered to be catalyzed by peptidylglycine{alpha} -amidating monooxyganase ( PAM ) and that the authors investigated the PAM function by expression of PAM cDNA isolated from rat pituitary and its deletion mutant into COS-7 cells, reaching to the important findings of a singl PMA mRNA encoding two enzymes, namely one at 5 {prime} side, peptidylglicine {alpha} hydroxylase which catalyses the conversion of C-termianl glycine on peptide to the hydroxylated form ( the first step of amidation ),and another at 3{prime} side, {alpha}- hydroxylglycine amidating dealkylase which catalyzes the conversion of hydroxylated glycine to the amidated form ( the second step of amidation). 19 refs., 4 figs.

  3. Conjugation of insulin onto the sidewalls of single-walled carbon nanotubes through functionalization and diimide-activated amidation

    Ng, Chee Meng; Loh, Hwei-San; Muthoosamy, Kasturi; Sridewi, Nanthini; Manickam, Sivakumar

    2016-01-01

    Purpose The high aspect ratio of carbon nanotubes (CNTs) allows the attachment of compounds that enhance the functionality of the drug vehicle. Considering this, use of CNTs as a multifunctional insulin carrier may be an interesting prospect to explore. Materials and methods The carboxylic acid groups were functionalized on the sidewalls of single-walled CNTs (SWCNTs) followed by diimidation to form amide bonds with the amine groups of the insulin. Results Scanning transmission electron microscopy and transmission electron microscopy establish clear conjugation of insulin onto the surface of nanotube sidewalls. The incorporation of insulin further increased the solubility of SWCNTs in biological solution for the tested period of 5 months. Bicinchoninic acid assay confirms that 0.42 mg of insulin could be attached to every 1 mg of carboxylated SWCNTs. Conclusion With the successful conjugation of insulin to SWCNTs, it opens up the potential use of SWCNTs as an insulin carrier which in need of further biological studies.

  4. Structure of a Nudix hydrolase (MutT) in the Mg2+-bound state from Bartonella henselae, the bacterium responsible for cat scratch fever

    B. henselae is the etiological agent responsible for cat scratch fever (bartonellosis). The crystal structure of the smaller of the two Nudix hydrolases encoded in the genome of B. henselae, Bh-MutT, was determined to 2.1 Å resolution. Cat scratch fever (also known as cat scratch disease and bartonellosis) is an infectious disease caused by the proteobacterium Bartonella henselae following a cat scratch. Although the infection usually resolves spontaneously without treatment in healthy adults, bartonellosis may lead to severe complications in young children and immunocompromised patients, and there is new evidence suggesting that B. henselae may be associated with a broader range of clinical symptoms then previously believed. The genome of B. henselae contains genes for two putative Nudix hydrolases, BH02020 and BH01640 (KEGG). Nudix proteins play an important role in regulating the intracellular concentration of nucleotide cofactors and signaling molecules. The amino-acid sequence of BH02020 is similar to that of the prototypical member of the Nudix superfamily, Escherichia coli MutT, a protein that is best known for its ability to neutralize the promutagenic compound 7,8-dihydro-8-oxoguanosine triphosphate. Here, the crystal structure of BH02020 (Bh-MutT) in the Mg2+-bound state was determined at 2.1 Å resolution. As observed in all Nudix hydrolase structures, the α-helix of the highly conserved ‘Nudix box’ in Bh-MutT is one of two helices that sandwich a four-stranded mixed β-sheet with the central two β-strands parallel to each other. The catalytically essential divalent cation observed in the Bh-MutT structure, Mg2+, is coordinated to the side chains of Glu57 and Glu61. The structure is not especially robust; a temperature melt obtained using circular dichroism spectroscopy shows that Bh-MutT irreversibly unfolds and precipitates out of solution upon heating, with a Tm of 333 K

  5. Catalyst-free synthesis of sodium amide nanoparticles encapsulated in silica gel

    Ogilvie, Alexander D., E-mail: alexander.ogilvie@chem.oxon.org [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Makepeace, Joshua W., E-mail: josh.makepeace@chem.ox.ac.uk [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Hore, Katie, E-mail: katie.hore@chem.ox.ac.uk [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Ramirez-Cuesta, Anibal J., E-mail: timmy.ramirez-cuesta@stfc.ac.uk [ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Apperley, David C., E-mail: d.c.apperley@dur.ac.uk [EPSRC UK National Solid-State NMR Service, Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom); Mitchels, John M., E-mail: J.M.Mitchels@bath.ac.uk [Microscopy and Analysis Suite, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Edwards, Peter P., E-mail: peter.edwards@chem.ox.ac.uk [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Sartbaeva, Asel, E-mail: a.sartbaeva@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2013-12-12

    Highlights: • Catalyst-free formation of nanoparticulate sodium amide encased in silica gel. • In situ ammoniation using Inelastic Neutron Spectroscopy. • Reduced air- and moisture-sensitivity and no pyrophoricity. • An alternative method for nanoparticle synthesis under mild conditions. - Abstract: Crystalline sodium amide nanoparticles encapsulated in an amorphous silica framework were formed by ammoniation of a precursor material, silica gel loaded with metallic sodium, under mild conditions and without catalysis. This ammoniation was performed in situ on TOSCA beamline at ISIS, RAL, using anhydrous gaseous ammonia. The resulting material exhibits no pyrophoricity and much reduced air- and moisture-sensitivity compared to the bulk amide. The nanoparticles formed will offer a greatly increased surface area for chemical reactions where amide is currently used as an important ingredient for industrial applications. We anticipate that this method of sodium amide production will have a diversity of applications.

  6. Synthesis, Structure and Catalytic Activity Comparison of Tris- and Tetracoordinated Lanthanide Amides

    XIE,Mei-Hua(谢美华); LIU,Xin-Yuan(刘心元); WANG,Shao-Wu(王绍武); LIU,Li(刘莉); WU,Yong-Yong(吴勇勇); YANG,Gao-Sheng(杨高升); ZHOU,Shuang-Liu(周双六); SHENG,En-Hong(盛恩宏); HUANG,Zi-Xiang(黄子祥)

    2004-01-01

    Tetracoordinated lanthanide amides [(Me3Si)2N]3Ln (μ-Cl)Li(THF)3 (Ln=La (1), Pr (2)) were synthesized by the reaction of anhydrous lanthanide(Ⅲ) chlorides LnCl3 (Ln=La, Pr) with 3 equiv. of lithium bis(trimethylsilyl)amide (Me3Si)2NLi in THF, followed by recrystallization from toluene. Sublimation of 1 and 2 afforded the triscoordinate lanthanide amides [(Me3Si)2N]3Ln (Ln =La, Pr). The crystal structure of 2 was determined by X-ray diffraction analysis. The catalytic activity studies show that the tetracoordinate amides can be used as single-component MMA (methyl methacrylate) polymerization catalysts, while the triscoordinate amides showed poor activity on MMA polymerization under the same conditions.

  7. Pyrrolic Amide: A New Hydrogen Bond Building Block for Self-assembly

    YIN Zhen-Ming; LI Jian-Feng; HE Jia-Qi; ZHU Xiao-Qing; CHENG Jin-Pei

    2003-01-01

    @@ Molecular self-assembly has emerged as a powerful technology for the synthesis of nanostructured materials. In design of various molecular assemblies, hydrogen bonding is a preferably selected intra- or inter-molecular weak interaction in recent research by virtue of the directionality and specificity. The research for novel hydrogen bond building blocks that self-assembly into well defined structures is great important not only for gaining an understanding of the concepts of self-assembly but also for the design of new molecular materials. Pyrrolic amide moiety has one hydrogen bond acceptor (C =O) and two hydrogen bond donors (pyrrole NH and amide NH). By deliberately design, pyrrolic amide compounds would be new kinds hydrogen bond building blocks. So, pyrrolic amide compounds 1 ~ 6, which bear one, two or three pyrrolic amide moieties respectively, were designed and synthesized.

  8. Catalyst-free synthesis of sodium amide nanoparticles encapsulated in silica gel

    Highlights: • Catalyst-free formation of nanoparticulate sodium amide encased in silica gel. • In situ ammoniation using Inelastic Neutron Spectroscopy. • Reduced air- and moisture-sensitivity and no pyrophoricity. • An alternative method for nanoparticle synthesis under mild conditions. - Abstract: Crystalline sodium amide nanoparticles encapsulated in an amorphous silica framework were formed by ammoniation of a precursor material, silica gel loaded with metallic sodium, under mild conditions and without catalysis. This ammoniation was performed in situ on TOSCA beamline at ISIS, RAL, using anhydrous gaseous ammonia. The resulting material exhibits no pyrophoricity and much reduced air- and moisture-sensitivity compared to the bulk amide. The nanoparticles formed will offer a greatly increased surface area for chemical reactions where amide is currently used as an important ingredient for industrial applications. We anticipate that this method of sodium amide production will have a diversity of applications

  9. Data set of optimal parameters for colorimetric red assay of epoxide hydrolase activity.

    de Oliveira, Gabriel Stephani; Adriani, Patricia Pereira; Borges, Flavia Garcia; Lopes, Adriana Rios; Campana, Patricia T; Chambergo, Felipe S

    2016-09-01

    The data presented in this article are related to the research article entitled "Epoxide hydrolase of Trichoderma reesei: Biochemical properties and conformational characterization" [1]. Epoxide hydrolases (EHs) are enzymes that catalyze the hydrolysis of epoxides to the corresponding vicinal diols. This article describes the optimal parameters for the colorimetric red assay to determine the enzymatic activity, with an emphasis on the characterization of the kinetic parameters, pH optimum and thermal stability of this enzyme. The effects of reagents that are not resistant to oxidation by sodium periodate on the reactions can generate false positives and interfere with the final results of the red assay. PMID:27366781

  10. Effects of valproate derivatives I. Antiepileptic efficacy of amides, structural analogs and esters.

    Redecker, C; Altrup, U; Hoppe, D; Düsing, R; Speckmann, E J

    2000-01-01

    Derivatives of the antiepileptic drug valproate (VPA, 2-propylpentanoic acid) have been synthesized and tested in order to improve the intracellular availability of VPA. The buccal ganglia of Helix pomatia were used as a test nervous system and antiepileptic efficacies were reconfirmed using rat cortex in vivo. Epileptiform activities consisted of typical paroxysmal depolarization shifts (PDS) which appeared in the identified neuron B3 with application of pentylenetetrazol. Epileptiform activities were found to be accelerated, unaffected or blocked. (i) The Amide-derivatives 2-propylpentanamide and N,N-dipropyl-2-propylpentanamide, and short chain ester derivatives 1-O-(2-propylpentanoyl)-2,3-propandiol, 2,2-di(hydroxymethyl)-1-O-(2-propylpentanoyl)-1,3-propanediol and 2,2-di(hydroxymethyl)-1,3-di-O-(2-propylpentanoyl)-1,3-propanediol accelerated epileptiform activities. Membrane potential often shifted to a permanent depolarization which corresponded to the PDS-inactivation level. (ii) The structural analogs 1-cycloheptene-1-carboxylic acid and cyclooctanecarboxylic acid accelerated epileptiform activities only slightly or were without effects. (iii) The small VPA-ester, 2-propylpentanoic acid ethyl ester, decreased the epileptiform activities in a way that is comparable to the effects of VPA well known from previous studies. It thus could be thought as a VPA-pro-drug. (iv) The mannitol-esters 1-O-(2-propylpentanoyl)-D-mannitol and 3,4;5,6-Di-O-isopropylidene-1-O-(2-propylpentanoyl)-D-mannitol blocked the PDS in a way which is different from the known effects of VPA. These substances are interpreted not to exert their effects after being metabolized to VPA and thus they are thought to be new antiepileptic substances. PMID:10670421

  11. Conformational Variability of Organophosphorus Hydrolase upon Soman and Paraoxon Binding

    Gomes, Diego Eb; Lins, Roberto D.; Pascutti, Pedro G.; Lei, Chenghong; Soares, Thereza A.

    2011-12-31

    The bacterial enzyme organophosphorus hydrolase (OPH) exhibits both catalytic and substrate promiscuity. It hydrolyzes bonds in a variety of phosphotriester (P-O), phosphonothioate (P-S), phosphofluoridate (P-F) and phosphonocyanate (F-CN) compounds. However, its catalytic efficiency varies markedly for different substrates, limiting the broad-range application of OPH as catalyst in the bioremediation of pesticides and chemical war agents. In the present study, pK{sub a} calculations and multiple explicit-solvent molecular dynamics (MD) simulations were performed to characterize and contrast the structural dynamics of OPH bound to two substrates hydrolyzed with very distinct catalytic efficiencies: the nerve agent soman (O-pinacolyl-methyl-phosphonofluoridate) and the pesticide paraoxon (diethyl p-nitrophenyl phosphate). pK{sub a} calculations for the substrate-bound and unbound enzyme showed a significant pK{sub a} shift from standard values ({Delta}pK{sub a} = {+-} 3 units) for residues 254His and 275Arg. MD simulations of the doubly protonated 254His revealed a dynamic hydrogen bond network connecting the catalytic residue 301Asp via 254His to 232Asp, 233Asp, 275Arg and 235Asp, and is consistent with a previously postulated proton relay mechanism to ferry protons away from the active site with substrates that do not require activation of the leaving group. Hydrogen bonds between 301Asp and 254His were persistent in the OPH-paraoxon complex but not in the OPH-soman one, suggesting a potential role for such interaction in the more efficient hydrolysis of paraoxon over soman by OPH. These results are in line with previous mutational studies of residue 254His, which led to an increase of the catalytic efficiency of OPH over soman yet decreased its efficiency for paraoxon. In addition, comparative analysis of the molecular trajectories for OPH bound to soman and paraoxon suggests that binding of the latter facilitates the conformational transition of OPH from the

  12. Soluble epoxide hydrolase inhibition and gene deletion are protective against myocardial ischemia-reperfusion injury in vivo.

    Motoki, Atsuko; Merkel, Matthias J; Packwood, William H; Cao, Zhiping; Liu, Lijuan; Iliff, Jeffrey; Alkayed, Nabil J; Van Winkle, Donna M

    2008-11-01

    Soluble epoxide hydrolase (sEH) metabolizes epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids. EETs are formed from arachidonic acid during myocardial ischemia and play a protective role against ischemic cell death. Deletion of sEH has been shown to be protective against myocardial ischemia in the isolated heart preparation. We tested the hypothesis that sEH inactivation by targeted gene deletion or pharmacological inhibition reduces infarct size (I) after regional myocardial ischemia-reperfusion injury in vivo. Male C57BL\\6J wild-type or sEH knockout mice were subjected to 40 min of left coronary artery (LCA) occlusion and 2 h of reperfusion. Wild-type mice were injected intraperitoneally with 12-(3-adamantan-1-yl-ureido)-dodecanoic acid butyl ester (AUDA-BE), a sEH inhibitor, 30 min before LCA occlusion or during ischemia 10 min before reperfusion. 14,15-EET, the main substrate for sEH, was administered intravenously 15 min before LCA occlusion or during ischemia 5 min before reperfusion. The EET antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (EEZE) was given intravenously 15 min before reperfusion. Area at risk (AAR) and I were assessed using fluorescent microspheres and triphenyltetrazolium chloride, and I was expressed as I/AAR. I was significantly reduced in animals treated with AUDA-BE or 14,15-EET, independent of the time of administration. The cardioprotective effect of AUDA-BE was abolished by the EET antagonist 14,15-EEZE. Immunohistochemistry revealed abundant sEH protein expression in left ventricular tissue. Strategies to increase 14,15-EET, including sEH inactivation, may represent a novel therapeutic approach for cardioprotection against myocardial ischemia-reperfusion injury. PMID:18835921

  13. Fatty Acid-binding Proteins (FABPs) Are Intracellular Carriers for Δ9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD)*

    Elmes, Matthew W.; Kaczocha, Martin; Berger, William T.; Leung, KwanNok; Ralph, Brian P.; Wang, Liqun; Sweeney, Joseph M.; Miyauchi, Jeremy T.; Tsirka, Stella E.; Ojima, Iwao; Deutsch, Dale G.

    2015-01-01

    Δ9-Tetrahydrocannabinol (THC) and cannabidiol (CBD) occur naturally in marijuana (Cannabis) and may be formulated, individually or in combination in pharmaceuticals such as Marinol or Sativex. Although it is known that these hydrophobic compounds can be transported in blood by albumin or lipoproteins, the intracellular carrier has not been identified. Recent reports suggest that CBD and THC elevate the levels of the endocannabinoid anandamide (AEA) when administered to humans, suggesting that phytocannabinoids target cellular proteins involved in endocannabinoid clearance. Fatty acid-binding proteins (FABPs) are intracellular proteins that mediate AEA transport to its catabolic enzyme fatty acid amide hydrolase (FAAH). By computational analysis and ligand displacement assays, we show that at least three human FABPs bind THC and CBD and demonstrate that THC and CBD inhibit the cellular uptake and catabolism of AEA by targeting FABPs. Furthermore, we show that in contrast to rodent FAAH, CBD does not inhibit the enzymatic actions of human FAAH, and thus FAAH inhibition cannot account for the observed increase in circulating AEA in humans following CBD consumption. Using computational molecular docking and site-directed mutagenesis we identify key residues within the active site of FAAH that confer the species-specific sensitivity to inhibition by CBD. Competition for FABPs may in part or wholly explain the increased circulating levels of endocannabinoids reported after consumption of cannabinoids. These data shed light on the mechanism of action of CBD in modulating the endocannabinoid tone in vivo and may explain, in part, its reported efficacy toward epilepsy and other neurological disorders. PMID:25666611

  14. Fatty acid-binding proteins (FABPs) are intracellular carriers for Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD).

    Elmes, Matthew W; Kaczocha, Martin; Berger, William T; Leung, KwanNok; Ralph, Brian P; Wang, Liqun; Sweeney, Joseph M; Miyauchi, Jeremy T; Tsirka, Stella E; Ojima, Iwao; Deutsch, Dale G

    2015-04-01

    Δ(9)-Tetrahydrocannabinol (THC) and cannabidiol (CBD) occur naturally in marijuana (Cannabis) and may be formulated, individually or in combination in pharmaceuticals such as Marinol or Sativex. Although it is known that these hydrophobic compounds can be transported in blood by albumin or lipoproteins, the intracellular carrier has not been identified. Recent reports suggest that CBD and THC elevate the levels of the endocannabinoid anandamide (AEA) when administered to humans, suggesting that phytocannabinoids target cellular proteins involved in endocannabinoid clearance. Fatty acid-binding proteins (FABPs) are intracellular proteins that mediate AEA transport to its catabolic enzyme fatty acid amide hydrolase (FAAH). By computational analysis and ligand displacement assays, we show that at least three human FABPs bind THC and CBD and demonstrate that THC and CBD inhibit the cellular uptake and catabolism of AEA by targeting FABPs. Furthermore, we show that in contrast to rodent FAAH, CBD does not inhibit the enzymatic actions of human FAAH, and thus FAAH inhibition cannot account for the observed increase in circulating AEA in humans following CBD consumption. Using computational molecular docking and site-directed mutagenesis we identify key residues within the active site of FAAH that confer the species-specific sensitivity to inhibition by CBD. Competition for FABPs may in part or wholly explain the increased circulating levels of endocannabinoids reported after consumption of cannabinoids. These data shed light on the mechanism of action of CBD in modulating the endocannabinoid tone in vivo and may explain, in part, its reported efficacy toward epilepsy and other neurological disorders. PMID:25666611

  15. Small Antimicrobial Agents Based on Acylated Reduced Amide Scaffold.

    Teng, Peng; Huo, Da; Nimmagadda, Alekhya; Wu, Jianfeng; She, Fengyu; Su, Ma; Lin, Xiaoyang; Yan, Jiyu; Cao, Annie; Xi, Chuanwu; Hu, Yong; Cai, Jianfeng

    2016-09-01

    Prevalence of drug-resistant bacteria has emerged to be one of the greatest threats in the 21st century. Herein, we report the development of a series of small molecular antibacterial agents that are based on the acylated reduced amide scaffold. These molecules display good potency against a panel of multidrug-resistant Gram-positive and Gram-negative bacterial strains. Meanwhile, they also effectively inhibit the biofilm formation. Mechanistic studies suggest that these compounds kill bacteria by compromising bacterial membranes, a mechanism analogous to that of host-defense peptides (HDPs). The mechanism is further supported by the fact that the lead compounds do not induce resistance in MRSA bacteria even after 14 passages. Lastly, we also demonstrate that these molecules have therapeutic potential by preventing inflammation caused by MRSA induced pneumonia in a rat model. This class of compounds could lead to an appealing class of antibiotic agents combating drug-resistant bacterial strains. PMID:27526720

  16. Lead optimization studies of cinnamic amide EP2 antagonists.

    Ganesh, Thota; Jiang, Jianxiong; Yang, Myung-Soon; Dingledine, Ray

    2014-05-22

    Prostanoid receptor EP2 can play a proinflammatory role, exacerbating disease pathology in a variety of central nervous system and peripheral diseases. A highly selective EP2 antagonist could be useful as a drug to mitigate the inflammatory consequences of EP2 activation. We recently identified a cinnamic amide class of EP2 antagonists. The lead compound in this class (5d) displays anti-inflammatory and neuroprotective actions. However, this compound exhibited moderate selectivity to EP2 over the DP1 prostanoid receptor (∼10-fold) and low aqueous solubility. We now report compounds that display up to 180-fold selectivity against DP1 and up to 9-fold higher aqueous solubility than our previous lead. The newly developed compounds also display higher selectivity against EP4 and IP receptors and a comparable plasma pharmacokinetics. Thus, these compounds are useful for proof of concept studies in a variety of models where EP2 activation is playing a deleterious role. PMID:24773616

  17. Catalysis of a Flavoenzyme-Mediated Amide Hydrolysis

    Mukherjee, Tathagata; Zhang, Yang; Abdelwahed, Sameh; Ealick, Steven E.; Begley, Tadhg P. (Cornell); (TAM)

    2010-09-13

    A new pyrimidine catabolic pathway (the Rut pathway) was recently discovered in Escherichia coli K12. In this pathway, uracil is converted to 3-hydroxypropionate, ammonia, and carbon dioxide. The seven-gene Rut operon is required for this conversion. Here we demonstrate that the flavoenzyme RutA catalyzes the initial uracil ring-opening reaction to give 3-ureidoacrylate. This reaction, while formally a hydrolysis reaction, proceeds by an oxidative mechanism initiated by the addition of a flavin hydroperoxide to the C4 carbonyl. While peroxide-catalyzed amide hydrolysis has chemical precedent, we are not aware of a prior example of analogous chemistry catalyzed by flavin hydroperoxides. This study further illustrates the extraordinary catalytic versatility of the flavin cofactor.

  18. Three new amides from streptomyces sp. H7372

    Cheenpracha, Sarot; Borris, Robert P.; Tran, Tammy T.; Chang, Leng Chee, E-mail: lengchee@hawaii.ed [University of Hawaii Hilo, HI (United States). College of Pharmacy. Dept. of Pharmaceutical Sciences; Jee, Jap Meng; Seow, Heng Fong; Cheah, Hwen-Yee [Universiti Putra Malaysia, Selangor (Malaysia). Faculty of Medicine and Health Sciences. Department of Pathology. bImmunology Unit; Hoc, Coy Choke [University Malaysia Sabah (Malaysia). School of Science and Technology. Biotechnology Program

    2011-07-01

    Three new amides, methyl phenatate A (1), actiphenamide (2) and actiphenol 1-beta-D-glucopyranoside (3), along with thirteen known compounds, were isolated from the organic extract of a fermentation culture of Streptomyces sp. H7372. The structures were elucidated by spectroscopic methods including 1D- and 2D-NMR techniques, and MS analyses. Cycloheximide (6) and cyclo({Delta}Ala-L-Val) (8) gave a clear zone of inhibition of Ras-Raf-1 interaction in the yeast two hybrid assay which showed high potency with 10 and 25 mm clear ZOIs on SD His{sup -} and inactive on SD His{sup +} at 2.5 mug per disk, respectively. (author)

  19. Proposed Chevron Tengiz venture stalls amid Soviet political squabble

    This paper reports on the status of foreign investment in Soviet oil and gas joint ventures which has reached a critical juncture. Just as the U.S. is considering granting most favored nation trade status to the U.S.S.R., the joint venture petroleum deal seen as the litmus test for such deals-Chevron Corp.'s proposed addition of supergiant Tengiz oil field to its Caspian Sea joint venture-has stalled amid controversy. Unconfirmed reports from Soviet officials and other foreign joint venture participants in the U.S.S.R. have Chevron pulling out of the long negotiated, multibillion dollar project after the Soviets rejected the company's terms. Chevron, however, insists the project is still alive

  20. Interaction of Thioamides, Selenoamides, and Amides With Diiodine

    Nick Hadjiliadis

    2006-12-01

    Full Text Available We review the results of our work on the iodine interaction with thioamides, selenoamides, and amides. Complexes with (i “spoke” or “extended spoke” structures, D⋅I2 and D⋅I2⋅I2, respectively, (D is the ligand donor (ii iodonium salts of {[D2−I]+[In]−} (n=3, 7 and {[D2−I]+[FeCl4]−} formulae and (iii disulfides of the categories (a [D-D], (b {[D-DH]+[I3]−} have been isolated and characterized. A compound of formula {[D2−I]+[I3]−[D⋅I2]} containing both types of complexes (i and (ii was also isolated. The interaction of diiodine with selenium analogs of the antithyroid drug 6-n-propyl-2-thiouracil (PTU, of formulae RSeU (6-alkyl-2-Selenouracil results in the formation of complexes with formulae [(RSeUI2]. All these results are correlated with the mechanism of action of antithyroid drugs. Finally, we review here our work on the diiodine interaction with the amides (LO.

  1. Isolation, Identification and Partial Characterization of a Lactobacillus casei Strain with Bile Salt Hydrolase Activity from Pulque.

    González-Vázquez, R; Azaola-Espinosa, A; Mayorga-Reyes, L; Reyes-Nava, L A; Shah, N P; Rivera-Espinoza, Y

    2015-12-01

    The aim of this study was to isolate, from pulque, Lactobacillus spp. capable of survival in simulated gastrointestinal stress conditions. Nine Gram-positive rods were isolated; however, only one strain (J57) shared identity with Lactobacillus and was registered as Lactobacillus casei J57 (GenBank accession: JN182264). The other strains were identified as Bacillus spp. The most significant observation during the test of tolerance to simulated gastrointestinal conditions (acidity, gastric juice and bile salts) was that L. casei J57 showed a rapid decrease (p ≤ 0.05) in the viable population at 0 h. Bile salts were the stress condition that most affected its survival, from which deoxycholic acid and the mix of bile salts (oxgall) were the most toxic. L. casei J57 showed bile salt hydrolase activity over primary and secondary bile salts as follows: 44.91, 671.72, 45.27 and 61.57 U/mg to glycocholate, taurocholate, glycodeoxycholate and taurodeoxycholate. In contrast, the control strain (L. casei Shirota) only showed activity over tauroconjugates. These results suggest that L. casei J57 shows potential for probiotic applications. PMID:26566892

  2. Application of the Kombucha 'tea fungus' for the enhancement of antioxidant and starch hydrolase inhibitory properties of ten herbal teas.

    Watawana, Mindani I; Jayawardena, Nilakshi; Choo, Candy; Waisundara, Viduranga Y

    2016-03-01

    Ten herbal teas (Acacia arabica, Aegle marmelos flower, A. marmelos root bark, Aerva lanata, Asteracantha longifolia, Cassia auriculata, Hemidesmus indicus, Hordeum vulgare, Phyllanthus emblica, Tinospora cordifolia) were fermented with the Kombucha 'tea fungus'. The pH values of the fermented beverages ranged from 4.0 to 6.0 by day 7, while the titratable acidity ranged from 2.5 to 5.0g/mL (P<0.05). Gallic acid had statistically significantly increased (P<0.05) in almost all the samples by day 7. The Oxygen radical absorbance capacity assay indicated 5 of the Kombucha beverages to have statistically significant increases (P<0.05) by day 7. The α-amylase inhibitory activities ranged from 52.5 to 67.2μg/mL in terms of IC50 values following fermentation, while the α-glucosidase inhibitory activities ranged from 95.2 to 196.1μg/mL. In conclusion, an enhancement of the antioxidant and starch hydrolase inhibitory potential of the herbal teas was observed by adding the tea fungus. PMID:26471559

  3. Engineering of Family-5 Glycoside Hydrolase (Cel5A) from an Uncultured Bacterium for Efficient Hydrolysis of Cellulosic Substrates

    Telke, Amar A.; Zhuang, Ningning; Ghatge, Sunil S.; Lee, Sook-Hee; Ali Shah, Asad; Khan, Haji; Um, Youngsoon; Shin, Hyun-Dong; Chung, Young Ryun; Lee, Kon Ho; Kim, Seon-Won

    2013-01-01

    Cel5A, an endoglucanase, was derived from the metagenomic library of vermicompost. The deduced amino acid sequence of Cel5A shows high sequence homology with family-5 glycoside hydrolases, which contain a single catalytic domain but no distinct cellulose-binding domain. Random mutagenesis and cellulose-binding module (CBM) fusion approaches were successfully applied to obtain properties required for cellulose hydrolysis. After two rounds of error-prone PCR and screening of 3,000 mutants, amino acid substitutions were identified at various positions in thermotolerant mutants. The most heat-tolerant mutant, Cel5A_2R2, showed a 7-fold increase in thermostability. To enhance the affinity and hydrolytic activity of Cel5A on cellulose substrates, the family-6 CBM from Saccharophagus degradans was fused to the C-terminus of the Cel5A_2R2 mutant using overlap PCR. The Cel5A_2R2-CBM6 fusion protein showed 7-fold higher activity than the native Cel5A on Avicel and filter paper. Cellobiose was a major product obtained from the hydrolysis of cellulosic substrates by the fusion enzyme, which was identified by using thin layer chromatography analysis. PMID:23785445

  4. Identification of the conserved spatial position of key active-site atoms in glycoside hydrolase 13 family members.

    Kumar, Vikash

    2010-07-19

    A computational study on the glycoside hydrolase 13 (GH13) family of the CAZy database has been carried out at the atomic level in order to identify the conserved positions that may be responsible for recognition of the substrate. Analysis with substrate analog-, inhibitor-, or product-bound 3D structures was carried out to find the atomic spatial arrangement of the amino acids that make -2, -1, +1, and +2 subsites and water oxygen atoms around the ligand. The identified conserved positions of subsites were independent from the nature of the amino acid. The -1 and +1 subsites have more conserved positions than the -2 and +2 subsites. Some of the clusters of the -1 and +1 subsites have atoms of the same chemical nature. A spatially conserved position for water, which is stabilized by a hydrogen bond with the carboxyl group of a proton donor (Glu) and Asp of the catalytic triad, was found in the -1 subsite of 75% of the enzymes subjected to analysis. This position could be the region of hydrolytic water. PMID:20557875

  5. Conformational Change in the Active Site of Streptococcal Unsaturated Glucuronyl Hydrolase Through Site-Directed Mutagenesis at Asp-115.

    Nakamichi, Yusuke; Oiki, Sayoko; Mikami, Bunzo; Murata, Kousaku; Hashimoto, Wataru

    2016-08-01

    Bacterial unsaturated glucuronyl hydrolase (UGL) degrades unsaturated disaccharides generated from mammalian extracellular matrices, glycosaminoglycans, by polysaccharide lyases. Two Asp residues, Asp-115 and Asp-175 of Streptococcus agalactiae UGL (SagUGL), are completely conserved in other bacterial UGLs, one of which (Asp-175 of SagUGL) acts as a general acid and base catalyst. The other Asp (Asp-115 of SagUGL) also affects the enzyme activity, although its role in the enzyme reaction has not been well understood. Here, we show substitution of Asp-115 in SagUGL with Asn caused a conformational change in the active site. Tertiary structures of SagUGL mutants D115N and D115N/K370S with negligible enzyme activity were determined at 2.00 and 1.79 Å resolution, respectively, by X-ray crystallography. The side chain of Asn-115 is drastically shifted in both mutants owing to the interaction with several residues, including Asp-175, by formation of hydrogen bonds. This interaction between Asn-115 and Asp-175 probably prevents the mutants from triggering the enzyme reaction using Asp-175 as an acid catalyst. PMID:27402448

  6. New synthesis route for ternary transition metal amides as well as ultrafast amide-hydride hydrogen storage materials.

    Cao, Hujun; Santoru, Antonio; Pistidda, Claudio; Richter, Theresia M M; Chaudhary, Anna-Lisa; Gizer, Gökhan; Niewa, Rainer; Chen, Ping; Klassen, Thomas; Dornheim, Martin

    2016-04-14

    K2[Mn(NH2)4] and K2[Zn(NH2)4] were successfully synthesized via a mechanochemical method. The mixture of K2[Mn(NH2)4] and LiH showed excellent rehydrogenation properties. In fact, after dehydrogenation K2[Mn(NH2)4]-8LiH fully rehydrogenates within 60 seconds at ca. 230 °C and 5 MPa of H2. This is one of the fastest rehydrogenation rates in amide-hydride systems known to date. This work also shows a strategy for the synthesis of transition metal nitrides by decomposition of the mixtures of M[M'(NH2)n] (where M is an alkali or alkaline earth metal and M' is a transition metal) and metal hydrides. PMID:26936831

  7. Efficacy of antiepileptic isomers of valproic acid and valpromide in a rat model of neuropathic pain

    Winkler, Ilan; Blotnik, Simcha; Shimshoni, Jakob; Yagen, Boris; Devor, Marshall; Bialer, Meir

    2005-01-01

    Antiepileptic drugs (AEDs) are often utilized in the treatment of neuropathic pain. The major AED valproic acid (VPA) is of particular interest as it is thought to engage a variety of different neural mechanisms simultaneously. However, the clinical use of VPA is limited by two rare but life-threatening side effects: teratogenicity and hepatotoxicity.We synthesized VPA's corresponding amide: valpromide (VPD), two of VPAs isomers and their corresponding amides; valnoctic acid (VCA), valnoctami...

  8. Oligogalacturonate hydrolase with unique substrate preference from the pulp of parsley roots

    Flodrová, Dana; Garajová, S.; Malovíková, A.; Mislovičová, D.; Omelková, J.; Stratilová, E.

    2009-01-01

    Roč. 64, č. 2 (2009), s. 228-234. ISSN 0006-3088 Institutional research plan: CEZ:AV0Z40310501 Keywords : exopolygalacturonase * oligogalacturonate hydrolase * Petroselium crispum Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.617, year: 2009

  9. Extracellular xylanolytic and pectinolytic hydrolase production by A. flavus isolates contributes to crop invasion

    Several atoxigenic Aspergillus flavus isolates, including some biocontrol agents, and one toxigenic isolate were surveyed for the ability to produce extracellular xylanolytic and pectinolytic hydrolases. All of the tested isolates displayed good production of endoxylanases when grown on a medium ut...

  10. Genetically lowered microsomal epoxide hydrolase activity and tobacco-related cancer in 47,000 individuals

    Lee, Julie; Dahl, Morten; Nordestgaard, Børge G

    2011-01-01

    Two functional polymorphisms of the microsomal epoxide hydrolase (mEH) gene (EPHX1), Tyr113His (rs1051740) and His139Arg (rs2234922), have variably been found to influence susceptibility to various cancer forms. We tested whether genetically lowered mEH activity affects risk of developing cancer in...

  11. Biosynthesis of intestinal microvillar proteins. Intracellular processing of lactase-phlorizin hydrolase

    Danielsen, E M; Skovbjerg, H; Norén, Ove;

    1984-01-01

    The biosynthesis of pig small intestinal lactase-phlorizin hydrolase (EC 3.2.1.23-62) was studied by labelling of organ cultured mucosal explants with [35S]methionine. The earliest detactable form of the enzyme was an intracellular, membrane-bound polypeptide of Mr 225 000, sensitive to endo H as...

  12. Discovery and characterization of thermophilic limonene-1,2-epoxide hydrolases from hot spring metagenomic libraries

    Ferrandi, Erica Elisa; Sayer, Christopher; Isupov, Michail N.;

    2015-01-01

    The epoxide hydrolases (EHs) represent an attractive option for the synthesis of chiral epoxides and 1,2-diols which are valuable building blocks for the synthesis of several pharmaceutical compounds. A metagenomic approach has been used to identify two new members of the atypical EH limonene-1...

  13. Novel prokaryotic epoxide hydrolase and Baeyer-Villiger monooxygenase genes from metagenome

    Štěpánek, Václav; Kotík, Michael; Marešová, Helena; Valešová, Renata; Grulich, Michal

    Bratislava : Československá spoločnosť mikrobiologická, 2010. s. 57-57. ISBN 970-80-970477-8-8 Institutional research plan: CEZ:AV0Z50200510 Keywords : epoxide hydrolases * environmental DNA Subject RIV: EE - Microbiology, Virology

  14. Environmental DNA as a source of a novel epoxide hydrolase reacting with aliphatic terminal epoxides

    Kotík, Michael; Štěpánek, Václav; Marešová, Helena; Kyslík, Pavel; Archelas, A.

    2009-01-01

    Roč. 56, č. 4 (2009), s. 288-293. ISSN 1381-1177 R&D Projects: GA ČR GA204/06/0458 Institutional research plan: CEZ:AV0Z50200510 Keywords : environmental DNA * metagenome * epoxide hydrolase Subject RIV: EE - Microbiology, Virology Impact factor: 2.400, year: 2009

  15. EXPRESSION AND CHARACTERIZATION OF THE RECOMBINANT JUVENILE HORMONE EPOXIDE HYDROLASE (JHEH) FROM MANDUCA SEXTA. (R825433)

    The cDNA of the microsomal Juvenile Hormone Epoxide Hydrolase (JHEH) from Manduca sexta was expressed in vitro in the baculovirus system. In insect cell culture, the recombinant enzyme (Ms-JHEH) was produced at a high level (100 fold over background EH catalytic activit...

  16. Recent developments in the electronic spectroscopy of amides and alpha-helical polypeptides.

    Woody, Robert W; Koslowski, Axel

    2002-12-10

    Recent experimental and theoretical advances in understanding the electronic excited states of simple amides are reviewed. Polarized reflection spectroscopy of single crystals of N-acetylglycine shows that the direction of the first pipi* (NV(1)) transition dipole moment of a secondary amide differs by approximately 15 degrees from that of a primary amide. Ab initio calculations on simple amides support this conclusion. Ab initio studies of di- and tri-amides demonstrate that several inter-amide charge-transfer (CT) transitions occur in the 150-175-nm region, between the NV(1) and NV(2) transitions. When the correct dipole transition moment direction for peptides is used in calculations of the circular dichroism of the alpha-helix, the results are much improved over those from earlier calculations that used the direction for primary amides. Studies that consider the mixing of the NV(1) transition with CT transitions are reviewed. These indicate that such mixing is likely to have a significant effect on the absorption and CD spectra of the alpha-helix and other types of peptide conformation. Nevertheless, the independent systems model gives a reasonable first approximation to the absorption and CD spectra of the alpha-helix. PMID:12488025

  17. Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database

    Akio Ichikawa

    2015-07-01

    Full Text Available Conformations of the crystalline 3,3,3-trifluoro-2-methoxy-2-phenylpropanamide derivatives (MTPA amides deposited in the Cambridge Structural Database (CSD were examined statistically as Racid-enantiomers. The majority of dihedral angles (48/58, ca. 83% of the amide carbonyl groups and the trifluoromethyl groups ranged from –30° to 0° with an average angle θ1 of −13°. The other conformational properties were also clarified: (1 one of the fluorine atoms was antiperiplanar (ap to the amide carbonyl group, forming a staggered conformation; (2 the MTPA amides prepared from primary amines showed a Z form in amide moieties; (3 in the case of the MTPA amide prepared from a primary amine possessing secondary alkyl groups (i.e., Mosher-type MTPA amide, the dihedral angles between the methine groups and the carbonyl groups were syn and indicative of a moderate conformational flexibility; (4 the phenyl plane was inclined from the O–Cchiral bond of the methoxy moiety with an average dihedral angle θ2 of +21°; (5 the methyl group of the methoxy moiety was ap to the ipso-carbon atom of the phenyl group.

  18. The Utilization of Amide Groups To Expand and Functionalize Metal-Organic Frameworks Simultaneously.

    Lu, Zhiyong; Bai, Junfeng; Hang, Cheng; Meng, Fei; Liu, Wenlong; Pan, Yi; You, Xiaozeng

    2016-04-25

    A new stepwise ligand-elongation strategy by amide spacers is utilized to prepare isoreticularly high-porous metal-organic frameworks (MOFs), namely, quasi-mesoporous [Cu2 (PDBAD)(H2 O)]n (H4 PDBAD=5,5'-((4,4'-((pyridine-3,5-dicarbonyl)bis(azanediyl))bis(benzoyl))bis(azanediyl))diisophthalic acid; NJU-Bai22: NJU-Bai for Nanjing University Bai's group), and mesoporous [Cu2 (PABAD)(H2 O)]n (H4 PABAD=5,5'-((4,4'-((4,4'-((pyridine-3,5-dicarbonyl)bis(azanediyl))bis(benzoyl))bis (azanediyl))bis(benzoyl))bis(azanediyl))diisophthalic acid; NJU-Bai23). Compared with the prototypical MOF of [Cu2 (PDAD)(H2 O)]n (H4 PDAD=5,5'-(pyridine-3,5-dicarbonyl)bis(azanediyl)diisophthalic acid; NJU-Bai21, also termed as PCN-124), both MOFs exhibit almost the same CO2 adsorption enthalpy and CO2 selectivity values, and better capacity for CO2 storage under high pressure; these results make them promising candidate materials for CO2 capture and sequestration. Interestingly, this new method, in comparison with traditional strategies of using phenyl or triple-bond spacers, is easier and cheaper, resulting in a better ability to retain high CO2 affinity and selectivity in MOFs with large pores and high CO2 storage capacity. Additionally, it may lead to the high thermal stability of the MOFs and also their tolerance to water, which is related to the balance between the density of functional groups and pore sizes. Therefore, this strategy could provide new opportunities to explore more functionalized mesoporous MOFs with high performance. PMID:27031809

  19. Self-assembly of gibberellic amide assemblies and their applications in the growth and fabrication of ordered gold nanoparticles

    Smoak, Evan M.; Carlo, Andrew D.; Fowles, Catherine C.; Banerjee, Ipsita A.

    2010-01-01

    Gibberellins are a group of naturally occurring diterpenoid based phytohormones that play a vital role in plant growth and development. In this work, we have studied the self-assembly of gibberellic acid, a phytohormone, which belongs to the family of gibberellins, and designed amide derivatives of gibberellic acid (GA3) for the facile, green synthesis of gold nanoparticles. It was found that the derivatives self-assembled into nanofibers and nanoribbons in aqueous solutions at varying pH. Further, upon incubation with tetrachloroaurate, the self-assembled GA3-amide derivatives efficiently nucleated and formed gold nanoparticles when heated to 60 °C. Energy dispersive x-ray spectroscopy, transmission electron microscopy and scanning electron microscopy analyses revealed that uniform coatings of gold nanoparticles in the 10-20 nm range were obtained at low pH on the nanowire surfaces without the assistance of additional reducing agents. This simple method for the development of morphology controlled gold nanoparticles using a plant hormone derivative opens doors for a new class of plant biomaterials which can efficiently yield gold nanoparticles in an environmentally friendly manner. The gold encrusted nanowires formed using biomimetic methods may lead on to the formation of conductive nanowires, which may be useful for a wide range of applications such as in optoelectronics and sensors. Further, the spontaneous formation of highly organized nanostructures obtained from plant phytohormone derivatives such as gibberellic acid is of particular interest as it might help in further understanding the supramolecular assembly mechanism of more highly organized biological structures.

  20. Self-assembly of gibberellic amide assemblies and their applications in the growth and fabrication of ordered gold nanoparticles

    Gibberellins are a group of naturally occurring diterpenoid based phytohormones that play a vital role in plant growth and development. In this work, we have studied the self-assembly of gibberellic acid, a phytohormone, which belongs to the family of gibberellins, and designed amide derivatives of gibberellic acid (GA3) for the facile, green synthesis of gold nanoparticles. It was found that the derivatives self-assembled into nanofibers and nanoribbons in aqueous solutions at varying pH. Further, upon incubation with tetrachloroaurate, the self-assembled GA3-amide derivatives efficiently nucleated and formed gold nanoparticles when heated to 60 deg. C. Energy dispersive x-ray spectroscopy, transmission electron microscopy and scanning electron microscopy analyses revealed that uniform coatings of gold nanoparticles in the 10-20 nm range were obtained at low pH on the nanowire surfaces without the assistance of additional reducing agents. This simple method for the development of morphology controlled gold nanoparticles using a plant hormone derivative opens doors for a new class of plant biomaterials which can efficiently yield gold nanoparticles in an environmentally friendly manner. The gold encrusted nanowires formed using biomimetic methods may lead on to the formation of conductive nanowires, which may be useful for a wide range of applications such as in optoelectronics and sensors. Further, the spontaneous formation of highly organized nanostructures obtained from plant phytohormone derivatives such as gibberellic acid is of particular interest as it might help in further understanding the supramolecular assembly mechanism of more highly organized biological structures.