Microwave-assisted synthesis of 3-aminobenzo[b]thiophene scaffolds for the preparation of kinase inhibitors.

PubMed

Bagley, Mark C; Dwyer, Jessica E; Molina, Maria D Beltran; Rand, Alexander W; Rand, Hayley L; Tomkinson, Nicholas C O

2015-06-28

Microwave irradiation of 2-halobenzonitriles and methyl thioglycolate in the presence of triethylamine in DMSO at 130 °C provides rapid access to 3-aminobenzo[b]thiophenes in 58-96% yield. This transformation has been applied in the synthesis of the thieno[2,3-b]pyridine core motif of LIMK1 inhibitors, the benzo[4,5]thieno[3,2-e][1,4]diazepin-5(2H)-one scaffold of MK2 inhibitors and a benzo[4,5]thieno[3,2-d]pyrimidin-4-one inhibitor of the PIM kinases.

Synthesis and Evaluation of Novel RSK Inhibitors in a Living Human Breast Model

DTIC Science & Technology

2015-09-01

the n- propyl carbamate analogue 9, and the sec-butyl carbamate analogue 10. The modified synthetic route could also be applied to the synthesis of...AWARD NUMBER: W81XWH-11-1-0068 TITLE: Synthesis and Evaluation of Novel RSK Inhibitors in a Living Human Breast Model PRINCIPAL INVESTIGATOR...DATES COVERED 01 Jul 2011 – 30 Jun 2015 4. TITLE AND SUBTITLE Synthesis and Evaluation of Novel RSK Inhibitors in a Living Human Breast Model 5a

DOE Office of Scientific and Technical Information (OSTI.GOV)

Svensson Holm, Ann-Charlotte B., E-mail: ann-charlotte.svensson@liu.se; Experimental Pathology, Department of Clinical and Experimental Medicine, Linkoeping University, SE-581 85 Linkoeping; Bengtsson, Torbjoern

Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blockingmore » antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling.« less

Identification of Intestinal UDP-Glucuronosyltransferase Inhibitors in Green Tea (Camellia sinensis) Using a Biochemometric Approach: Application to Raloxifene as a Test Drug via In Vitro to In Vivo Extrapolation.

PubMed

Tian, Dan-Dan; Kellogg, Joshua J; Okut, Neşe; Oberlies, Nicholas H; Cech, Nadja B; Shen, Danny D; McCune, Jeannine S; Paine, Mary F

2018-05-01

Green tea ( Camellia sinensis ) is a popular beverage worldwide, raising concern for adverse interactions when co-consumed with conventional drugs. Like many botanical natural products, green tea contains numerous polyphenolic constituents that undergo extensive glucuronidation. As such, the UDP-glucuronosyltransferases (UGTs), particularly intestinal UGTs, represent potential first-pass targets for green tea-drug interactions. Candidate intestinal UGT inhibitors were identified using a biochemometrics approach, which combines bioassay and chemometric data. Extracts and fractions prepared from four widely consumed teas were screened (20-180 μ g/ml) as inhibitors of UGT activity (4-methylumbelliferone glucuronidation) in human intestinal microsomes; all demonstrated concentration-dependent inhibition. A biochemometrics-identified fraction rich in UGT inhibitors from a representative tea was purified further and subjected to second-stage biochemometric analysis. Five catechins were identified as major constituents in the bioactive subfractions and prioritized for further evaluation. Of these catechins, (-)-epicatechin gallate and (-)-epigallocatechin gallate showed concentration-dependent inhibition, with IC 50 values (105 and 59 μ M, respectively) near or below concentrations measured in a cup (240 ml) of tea (66 and 240 μ M, respectively). Using the clinical intestinal UGT substrate raloxifene, the K i values were ∼1.0 and 2.0 μ M, respectively. Using estimated intestinal lumen and enterocyte inhibitor concentrations, a mechanistic static model predicted green tea to increase the raloxifene plasma area under the curve up to 6.1- and 1.3-fold, respectively. Application of this novel approach, which combines biochemometrics with in vitro-in vivo extrapolation, to other natural product-drug combinations will refine these procedures, informing the need for further evaluation via dynamic modeling and clinical testing. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

The design and synthesis of novel N-hydroxyformamide inhibitors of ADAM-TS4 for the treatment of osteoarthritis.

PubMed

De Savi, Chris; Pape, Andrew; Cumming, John G; Ting, Attilla; Smith, Peter D; Burrows, Jeremy N; Mills, Mark; Davies, Chris; Lamont, Scott; Milne, David; Cook, Calum; Moore, Peter; Sawyer, Yvonne; Gerhardt, Stefan

2011-03-01

Two series of N-hydroxyformamide inhibitors of ADAM-TS4 were identified from screening compounds previously synthesised as inhibitors of matrix metalloproteinase-13 (collagenase-3). Understanding of the binding mode of this class of compound using ADAM-TS1 as a structural surrogate has led to the discovery of potent and very selective inhibitors with favourable DMPK properties. Synthesis, structure-activity relationships, and strategies to improve selectivity and lower in vivo metabolic clearance are described. Copyright © 2011 Elsevier Ltd. All rights reserved.

Requirement for the eIF4E binding proteins for the synergistic down-regulation of protein synthesis by hypertonic conditions and mTOR inhibition.

PubMed

Clemens, Michael J; Elia, Androulla; Morley, Simon J

2013-01-01

The protein kinase mammalian target of rapamycin (mTOR) regulates the phosphorylation and activity of several proteins that have the potential to control translation, including p70S6 kinase and the eIF4E binding proteins 4E-BP1 and 4E-BP2. In spite of this, in exponentially growing cells overall protein synthesis is often resistant to mTOR inhibitors. We report here that sensitivity of wild-type mouse embryonic fibroblasts (MEFs) to mTOR inhibitors can be greatly increased when the cells are subjected to the physiological stress imposed by hypertonic conditions. In contrast, protein synthesis in MEFs with a double knockout of 4E-BP1 and 4E-BP2 remains resistant to mTOR inhibitors under these conditions. Phosphorylation of p70S6 kinase and protein kinase B (Akt) is blocked by the mTOR inhibitor Ku0063794 equally well in both wild-type and 4E-BP knockout cells, under both normal and hypertonic conditions. The response of protein synthesis to hypertonic stress itself does not require the 4E-BPs. These data suggest that under certain stress conditions: (i) translation has a greater requirement for mTOR activity and (ii) there is an absolute requirement for the 4E-BPs for regulation by mTOR. Importantly, dephosphorylation of p70S6 kinase and Akt is not sufficient to affect protein synthesis acutely.

Pancreatic lipase and α-amylase inhibitory activities of plants used in Traditional Chinese Medicine (TCM).

PubMed

2016-07-07

To find new, plant based drugs for the treatment of obesity and/or diabetes mellitus type 2 through the inhibition of essential digestive enzymes, in vitro tests were carried out on selected plants or fungi with weight-reducing, blood glucose-reducing or related potential, used in Traditional Chinese Medicine (TCM). Aqueous and methanolic extracts of 32 Chinese herbal medicines were assayed for their in vitro inhibitory activity against pancreatic lipase (PL) and α-amylase (PA). PL activity was measured by using an enzymatic in vitro assay based on the hydrolysis kinetics of an oleate ester of 4-methylumbelliferone. For the determination of α-amylase activity an enzyme assay based on the hydrolytic cleavage of a modified starch derivative was used. Our findings have shown that the methanolic extract of Lycopus lucidus Turcz. var. hirtus Regel (Lamiaceae) was a very effective PL inhibitor (IC50: 88.3±4.1 μg/mL). A high anti-amylase activity showed the methanolic extract of Trichosanthes kirilowii Maxim. (Curcurbitaceae, IC50: 248.8±67.3 μg/mL). This work provides a priority list of interesting plants for further study with respect to the treatment of obesity and associated metabolic diseases.

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

PubMed

Bagley, Mark C; Baashen, Mohammed; Chuckowree, Irina; Dwyer, Jessica E; Kipling, David; Davis, Terence

2015-06-03

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

Design and Synthesis of 4-Heteroaryl 1,2,3,4-Tetrahydroisoquinolines as Triple Reuptake Inhibitors

PubMed Central

2014-01-01

A series of 4-bicyclic heteroaryl 1,2,3,4-tetrahydroisoquinoline inhibitors of the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT) was discovered. The synthesis and structure–activity relationship (SAR) of these triple reuptake inhibitors (TRIs) will be discussed. Compound 10i (AMR-2), a very potent inhibitor of SERT, NET, and DAT, showed efficacy in the rat forced-swim and mouse tail suspension models with minimum effective doses of 0.3 and 1 mg/kg (po), respectively. At efficacious doses in these assays, 10i exhibited substantial occupancy levels at the three transporters in both rat and mouse brain. The study of the metabolism of 10i revealed the formation of a significant active metabolite, compound 13. PMID:25050161

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

PubMed

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

2014-07-10

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

A simplified method for active-site titration of lipases immobilised on hydrophobic supports.

PubMed

Nalder, Tim D; Kurtovic, Ivan; Barrow, Colin J; Marshall, Susan N

2018-06-01

The aim of this work was to develop a simple and accurate protocol to measure the functional active site concentration of lipases immobilised on highly hydrophobic supports. We used the potent lipase inhibitor methyl 4-methylumbelliferyl hexylphosphonate to titrate the active sites of Candida rugosa lipase (CrL) bound to three highly hydrophobic supports: octadecyl methacrylate (C18), divinylbenzene crosslinked methacrylate (DVB) and styrene. The method uses correction curves to take into account the binding of the fluorophore (4-methylumbelliferone, 4-MU) by the support materials. We showed that the uptake of the detection agent by the three supports is not linear relative to the weight of the resin, and that the uptake occurs in an equilibrium that is independent of the total fluorophore concentration. Furthermore, the percentage of bound fluorophore varied among the supports, with 50 mg of C18 and styrene resins binding approximately 64 and 94%, respectively. When the uptake of 4-MU was calculated and corrected for, the total 4-MU released via inhibition (i.e. the concentration of functional lipase active sites) could be determined via a linear relationship between immobilised lipase weight and total inhibition. It was found that the functional active site concentration of immobilised CrL varied greatly among different hydrophobic supports, with 56% for C18, compared with 14% for DVB. The described method is a simple and robust approach to measuring functional active site concentration in immobilised lipase samples. Copyright © 2018 Elsevier Inc. All rights reserved.

An enantioselective enzymatic desymmetrization route to hexahydro-4H-furopyranol, a high-affinity ligand for HIV-1 protease inhibitors.

PubMed

Ghosh, Arun K; Sarkar, Anindya

2017-08-16

An enantioselective synthesis of ( 3 a S , 4S , 7 a R )-hexahydro-4 H -furo[2,3- b ]pyran-4-ol, a high-affinity nonpeptide ligand for a variety of potent HIV-1 protease inhibitors is described. The key steps involved a highly enantioselective enzymatic desymmetrization of meso -diacetate, an efficient transacetalization, and a highly diastereoselective reduction of a ketone. This route is amenable to large-scale synthesis using readily available starting materials.

Synthesis of novel 4,1-benzoxazepine derivatives as squalene synthase inhibitors and their inhibition of cholesterol synthesis.

PubMed

Miki, Takashi; Kori, Masakuni; Mabuchi, Hiroshi; Tozawa, Ryu-ichi; Nishimoto, Tomoyuki; Sugiyama, Yasuo; Teshima, Koichiro; Yukimasa, Hidefumi

2002-09-26

Modification of the carboxyl group at the 3-position and introduction of protective groups to the hydroxy group of the 4,1-benzoxazepine derivative 2 (metabolite of 1) were carried out, and the inhibitory activity for squalene synthase and cholesterol synthesis in the liver was investigated. Among these compounds, the glycine derivative 3a and beta-alanine derivative 3f exhibited the most potent inhibition of squalene synthase prepared from HepG2 cells (IC(50) = 15 nM). On the other hand, the piperidine-4-acetic acid derivative 4a, which was prepared by acetylation of 3j, was the most effective inhibitor of cholesterol synthesis in rat liver (ED(50) = 2.9 mg/kg, po). After oral administration, 4a was absorbed and rapidly hydrolyzed to deacylated 3j. Compound 3j was detected mainly in the liver, but the plasma level of 3j was found to be low. Compounds 3j and 4a were found to be competitive inhibitors with respect to farnesyl pyrophosphate. Further evaluation of 4a as a cholesterol-lowering and antiatherosclerotic agent is underway.

Inhibition of Dengue Virus RNA Synthesis by an Adenosine Nucleoside ▿ †

PubMed Central

Chen, Yen-Liang; Yin, Zheng; Duraiswamy, Jeyaraj; Schul, Wouter; Lim, Chin Chin; Liu, Boping; Xu, Hao Ying; Qing, Min; Yip, Andy; Wang, Gang; Chan, Wai Ling; Tan, Hui Pen; Lo, Melissa; Liung, Sarah; Kondreddi, Ravinder Reddy; Rao, Ranga; Gu, Helen; He, Handan; Keller, Thomas H.; Shi, Pei-Yong

2010-01-01

We recently reported that (2R,3R,4R,5R)-2-(4-amino-pyrrolo[2,3-d]pyrimidin-7-yl)-3-ethynyl-5-hydroxy-methyl-tetrahydro-furan-3,4-diol is a potent inhibitor of dengue virus (DENV), with 50% effective concentration (EC50) and cytotoxic concentration (CC50) values of 0.7 μM and >100 μM, respectively. Here we describe the synthesis, structure-activity relationship, and antiviral characterization of the inhibitor. In an AG129 mouse model, a single-dose treatment of DENV-infected mice with the compound suppressed peak viremia and completely prevented death. Mode-of-action analysis using a DENV replicon indicated that the compound blocks viral RNA synthesis. Recombinant adenosine kinase could convert the compound to a monophosphate form. Suppression of host adenosine kinase, using a specific inhibitor (iodotubercidin) or small interfering RNA (siRNA), abolished or reduced the compound's antiviral activity in cell culture. Studies of rats showed that 14C-labeled compound was converted to mono-, di-, and triphosphate metabolites in vivo. Collectively, the results suggest that this adenosine inhibitor is phosphorylated to an active (triphosphate) form which functions as a chain terminator for viral RNA synthesis. PMID:20457821

Inhibitors of adhesion molecules expression; the synthesis and pharmacological properties of 10H-pyrazino[2,3-b][1,4]benzothiazine derivatives.

PubMed

Kaneko, Toshihiko; Clark, Richard S J; Ohi, Norihito; Kawahara, Tetsuya; Akamatsu, Hiroshi; Ozaki, Fumihiro; Kamada, Atsushi; Okano, Kazuo; Yokohama, Hiromitsu; Muramoto, Kenzo; Ohkuro, Masayoshi; Takenaka, Osamu; Kobayashi, Seiichi

2002-07-01

During a search for novel, orally-active inhibitors of upregulation of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1), we found a new series of 10H-pyrazino[2,3-b][1,4]benzothiazine derivatives to be potent ICAM-1 inhibitors. Of these compounds, N-[1-(10H-Pyrazino[2,3-b][1,4]benzothiazin-8-ylmethyl)piperidin-4-yl]-N',N'-dimethylsulfamide 7p showed the potent oral inhibitory activities against neutrophil migration in a murine interleukin-1 (IL-1) induced paw inflammation model. The synthesis and structure-activity relationships of these amide derivatives are described.

Design, synthesis, and structure-activity relationships of 3,4-dihydropyridopyrimidin-2(1H)-one derivatives as a novel class of sodium/calcium exchanger inhibitor.

PubMed

Hasegawa, Hirohiko; Muraoka, Masami; Ohmori, Mikiko; Matsui, Kazuki; Kojima, Atsuyuki

2005-10-01

Design, synthesis, and structure-activity relationships for 3,4-dihydropyridopyrimidin-2(1H)-one derivatives, which are aza-3,4-dihydro-2(1H)-quinazolinone derivatives, as the sodium/calcium (Na+/Ca2+) exchanger inhibitors are discussed. These studies based on 3,4-dihydro-2(1H)-quinazolinone derivatives led to the discovery of a structurally novel and potent Na+/Ca2+ exchanger inhibitor, 3,4-dihydropyridopyrimidin-2(1H)-one derivative (26), with an IC30 value of 0.02 microM. Compound 26 directly inhibited the Na+-dependent Ca2+ influx via the Na+/Ca2+ exchanger after Na+-free treatment in cardiomyocytes.

Hyaluronan and Layilin Mediate Loss of Airway Epithelial Barrier Function Induced by Cigarette Smoke by Decreasing E-cadherin*

PubMed Central

Forteza, Rosanna Malbran; Casalino-Matsuda, S. Marina; Falcon, Nieves S.; Valencia Gattas, Monica; Monzon, Maria E.

2012-01-01

Cigarette smoke (CigS) exposure is associated with increased bronchial epithelial permeability and impaired barrier function. Primary cultures of normal human bronchial epithelial cells exposed to CigS exhibit decreased E-cadherin expression and reduced transepithelial electrical resistance. These effects were mediated by hyaluronan (HA) because inhibition of its synthesis with 4-methylumbelliferone prevented these effects, and exposure to HA fragments of <70 kDa mimicked these effects. We show that the HA receptor layilin is expressed apically in human airway epithelium and that cells infected with lentivirus expressing layilin siRNAs were protected against increased permeability triggered by both CigS and HA. We identified RhoA/Rho-associated protein kinase (ROCK) as the signaling effectors downstream layilin. We conclude that HA fragments generated by CigS bind to layilin and signal through Rho/ROCK to inhibit the E-cadherin gene and protein expression, leading to a loss of epithelial cell-cell contact. These studies suggest that HA functions as a master switch protecting or disrupting the epithelial barrier in its high versus low molecular weight form and that its depolymerization is a first and necessary step triggering the inflammatory response to CigS. PMID:23048036

Design, Synthesis and Biological Evaluation of 6-(2,6-Dichloro-3,5-dimethoxyphenyl)-4-substituted-1H-indazoles as Potent Fibroblast Growth Factor Receptor Inhibitors.

PubMed

Zhang, Zhen; Zhao, Dongmei; Dai, Yang; Cheng, Maosheng; Geng, Meiyu; Shen, Jingkang; Ma, Yuchi; Ai, Jing; Xiong, Bing

2016-10-23

Tyrosine kinase fibroblast growth factor receptor (FGFR), which is aberrant in various cancer types, is a promising target for cancer therapy. Here we reported the design, synthesis, and biological evaluation of a new series of 6-(2,6-dichloro-3,5-dimethoxyphenyl)-4-substituted-1 H -indazole derivatives as potent FGFR inhibitors. The compound 6-(2,6-dichloro-3,5-dimethoxyphenyl)- N -phenyl-1 H -indazole-4-carboxamide ( 10a ) was identified as a potent FGFR1 inhibitor, with good enzymatic inhibition. Further structure-based optimization revealed that 6-(2,6-dichloro-3,5-dimethoxyphenyl)- N -(3-(4-methylpiperazin-1-yl)phenyl)-1 H -indazole-4-carboxamide ( 13a ) is the most potent FGFR1 inhibitor in this series, with an enzyme inhibitory activity IC 50 value of about 30.2 nM.

Discovery and Structure Enabled Synthesis of 2,6-Diaminopyrimidin-4-one IRAK4 Inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seganish, W. Michael; Fischmann, Thierry O.; Sherborne, Brad

2015-08-13

We report the identification and synthesis of a series of aminopyrimidin-4-one IRAK4 inhibitors. Through high throughput screening, an aminopyrimidine hit was identified and modified via structure enabled design to generate a new, potent, and kinase selective pyrimidin-4-one chemotype. This chemotype is exemplified by compound 16, which has potent IRAK4 inhibition activity (IC50 = 27 nM) and excellent kinase selectivity (>100-fold against 99% of 111 tested kinases), and compound 31, which displays potent IRAK4 activity (IC50 = 93 nM) and good rat bioavailability (F = 42%).

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

PubMed Central

Bagley, Mark C.; Baashen, Mohammed; Chuckowree, Irina; Dwyer, Jessica E.; Kipling, David; Davis, Terence

2015-01-01

Microwave-assisted Suzuki-Miyaura cross-coupling reactions have been employed towards the synthesis of three different MAPKAPK2 (MK2) inhibitors to study accelerated aging in Werner syndrome (WS) cells, including the cross-coupling of a 2-chloroquinoline with a 3-pyridinylboronic acid, the coupling of an aryl bromide with an indolylboronic acid and the reaction of a 3-amino-4-bromopyrazole with 4-carbamoylphenylboronic acid. In all of these processes, the Suzuki-Miyaura reaction was fast and relatively efficient using a palladium catalyst under microwave irradiation. The process was incorporated into a rapid 3-step microwave-assisted method for the synthesis of a MK2 inhibitor involving 3-aminopyrazole formation, pyrazole C-4 bromination using N-bromosuccinimide (NBS), and Suzuki-Miyaura cross-coupling of the pyrazolyl bromide with 4-carbamoylphenylboronic acid to give the target 4-arylpyrazole in 35% overall yield, suitable for study in WS cells. PMID:26046488

Hyaluronic acid influence on platelet-induced airway smooth muscle cell proliferation.

PubMed

Svensson Holm, Ann-Charlotte B; Bengtsson, Torbjörn; Grenegård, Magnus; Lindström, Eva G

2012-03-10

Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blocking antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling. Copyright © 2011 Elsevier Inc. All rights reserved.

Podoscyphic acid, a new inhibitor of avian myeloblastosis virus and Moloney murine leukemia virus reverse transcriptase from a Podoscypha species.

PubMed

Erkel, G; Anke, T; Velten, R; Steglich, W

1991-01-01

A novel enzyme inhibitor of RNA-directed DNA-polymerases of avian myeloblastosis and murine leukemia virus was isolated from fermentations of an tasmanian Podoscypha species. Its structure was elucidated by spectroscopic methods and oxidative degradation as (E)-4,5-dioxo-2-hexadecenoic acid (1). The enzyme inhibitor, which was named podoscyphic acid, did not inhibit DNA and RNA synthesis in permeabilized L 1210 cells nor did it affect RNA synthesis in isolated nuclei of L 1210 cells. 1 inhibits protein synthesis in whole L 1210 cells and rabbit reticulocyte lysate and shows very weak antimicrobial and cytotoxic properties. The testing of ethyl (E)-4,5-dioxo-2-hexadecenoate (2) and (E)-4-oxo-2-tetradecenoic acid (11) revealed the importance of the free gamma-oxoacrylic acid unit for the biological activities of 1.

Synthesis of the Pitstop family of clathrin inhibitors.

PubMed

Robertson, Mark J; Deane, Fiona M; Stahlschmidt, Wiebke; von Kleist, Lisa; Haucke, Volker; Robinson, Phillip J; McCluskey, Adam

2014-07-01

This protocol describes the synthesis of two classes of clathrin inhibitors, Pitstop 1 and Pitstop 2, along with two inactive analogs that can be used as negative controls (Pitstop inactive controls, Pitnot-2 and Pitnot-2-100). Pitstop-induced inhibition of clathrin TD function acutely interferes with clathrin-mediated endocytosis (CME), synaptic vesicle recycling and cellular entry of HIV, whereas clathrin-independent internalization pathways and secretory traffic proceed unperturbed; these reagents can, therefore, be used to investigate clathrin function, and they have potential pharmacological applications. Pitstop 1 is synthesized in two steps: sulfonation of 1,8-naphthalic anhydride and subsequent reaction with 4-amino(methyl)aniline. Pitnot-1 results from the reaction of 4-amino(methyl)aniline with commercially available 4-sulfo-1,8-naphthalic anhydride potassium salt. Reaction of 1-naphthalene sulfonyl chloride with pseudothiohydantoin followed by condensation with 4-bromobenzaldehyde yields Pitstop 2. The synthesis of the inactive control commences with the condensation of 4-bromobenzaldehyde with the rhodanine core. Thioketone methylation and displacement with 1-napthylamine affords the target compound. Although Pitstop 1-series compounds are not cell permeable, they can be used in biochemical assays or be introduced into cells via microinjection. The Pitstop 2-series compounds are cell permeable. The synthesis of these compounds does not require specialist equipment and can be completed in 3-4 d. Microwave irradiation can be used to reduce the synthesis time. The synthesis of the Pitstop 2 family is easily adaptable to enable the synthesis of related compounds such as Pitstop 2-100 and Pitnot-2-100. The procedures are also simple, efficient and amenable to scale-up, enabling cost-effective in-house synthesis for users of these inhibitor classes.

Design, synthesis and biological evaluation of novel pyrazolo-pyrimidinones as DPP-IV inhibitors in diabetes.

PubMed

Sagar, Sneha R; Agarwal, Jessica K; Pandya, Dhaivat H; Dash, Ranjeet Prasad; Nivsarkar, Manish; Vasu, Kamala K

2015-10-15

We report the design, synthesis, biological activity and docking studies of series of novel pyrazolo[3,4-d]pyrimidinones as DPP-IV inhibitors in diabetes. Molecules were synthesized and evaluated for their DPP-IV inhibition activity. Compounds 5e, 5k, 5o and 6a were found to be potent inhibitors of DPP-IV enzyme. Amongst all the synthesized compounds, 6-methyl-5-(4-methylpyridin-2-yl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (5k) was found to be the most active based on in vitro DPP-IV studies and also exhibited promising in vivo blood glucose lowering activity in male Wistar rats. Copyright © 2015. Published by Elsevier Ltd.

Esophageal Squamous Cell Carcinoma Cells Modulate Chemokine Expression and Hyaluronan Synthesis in Fibroblasts.

PubMed

Kretschmer, Inga; Freudenberger, Till; Twarock, Sören; Yamaguchi, Yu; Grandoch, Maria; Fischer, Jens W

2016-02-19

The aim of this study was to characterize the interaction of KYSE-410, an esophageal squamous cell carcinoma cell line, and fibroblasts with respect to the extracellular matrix component hyaluronan (HA) and chemokine expression. KYSE-410 cells induced the mRNA expression of HA synthase 2 (Has2) in normal skin fibroblasts (SF) only in direct co-cultures. Parallel to Has2 mRNA, Has2 antisense RNA (Has2os2) was up-regulated in co-cultures. Knockdown of LEF1, a downstream target of Wnt signaling, abrogated Has2 and Has2os2 induction. After knockdown of Has2 in SF, significantly less α-smooth muscle actin expression was detected in co-cultures. Moreover, it was investigated whether the phenotype of KYSE-410 was affected in co-culture with SF and whether Has2 knockdown in SF had an impact on KYSE-410 cells in co-culture. However, no effects on epithelial-mesenchymal transition markers, proliferation, and migration were detected. In addition to Has2 mRNA, the chemokine CCL5 was up-regulated and CCL11 was down-regulated in SF in co-culture. Furthermore, co-cultures of KYSE-410 cells and cancer-associated fibroblasts (CAF) were investigated. Similar to SF, Has2 and Ccl5 were up-regulated and Ccl11 was down-regulated in CAF in co-culture. Importantly and in contrast to SF, inhibiting HA synthesis by 4-methylumbelliferone abrogated the effect of co-culture on Ccl5 in CAF. Moreover, HA was found to promote adhesion of CD4(+) but not CD8(+) cells to xenogaft tumor tissues. In conclusion, direct co-culture of esophageal squamous cell carcinoma and fibroblasts induced stromal HA synthesis via Wnt/LEF1 and altered the chemokine profile of stromal fibroblasts, which in turn may affect the tumor immune response. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Esophageal Squamous Cell Carcinoma Cells Modulate Chemokine Expression and Hyaluronan Synthesis in Fibroblasts*

PubMed Central

Kretschmer, Inga; Freudenberger, Till; Twarock, Sören; Yamaguchi, Yu; Grandoch, Maria; Fischer, Jens W.

2016-01-01

The aim of this study was to characterize the interaction of KYSE-410, an esophageal squamous cell carcinoma cell line, and fibroblasts with respect to the extracellular matrix component hyaluronan (HA) and chemokine expression. KYSE-410 cells induced the mRNA expression of HA synthase 2 (Has2) in normal skin fibroblasts (SF) only in direct co-cultures. Parallel to Has2 mRNA, Has2 antisense RNA (Has2os2) was up-regulated in co-cultures. Knockdown of LEF1, a downstream target of Wnt signaling, abrogated Has2 and Has2os2 induction. After knockdown of Has2 in SF, significantly less α-smooth muscle actin expression was detected in co-cultures. Moreover, it was investigated whether the phenotype of KYSE-410 was affected in co-culture with SF and whether Has2 knockdown in SF had an impact on KYSE-410 cells in co-culture. However, no effects on epithelial-mesenchymal transition markers, proliferation, and migration were detected. In addition to Has2 mRNA, the chemokine CCL5 was up-regulated and CCL11 was down-regulated in SF in co-culture. Furthermore, co-cultures of KYSE-410 cells and cancer-associated fibroblasts (CAF) were investigated. Similar to SF, Has2 and Ccl5 were up-regulated and Ccl11 was down-regulated in CAF in co-culture. Importantly and in contrast to SF, inhibiting HA synthesis by 4-methylumbelliferone abrogated the effect of co-culture on Ccl5 in CAF. Moreover, HA was found to promote adhesion of CD4+ but not CD8+ cells to xenogaft tumor tissues. In conclusion, direct co-culture of esophageal squamous cell carcinoma and fibroblasts induced stromal HA synthesis via Wnt/LEF1 and altered the chemokine profile of stromal fibroblasts, which in turn may affect the tumor immune response. PMID:26699196

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Design and synthesis of carbazole carboxamides as promising inhibitors of Bruton’s tyrosine kinase (BTK) and Janus kinase 2 (JAK2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Qingjie; Batt, Douglas G.; Lippy, Jonathan S.

Four series of disubstituted carbazole-1-carboxamides were designed and synthesised as inhibitors of Bruton’s tyrosine kinase (BTK). 4,7- and 4,6-disubstituted carbazole-1-carboxamides were potent and selective inhibitors of BTK, while 3,7- and 3,6-disubstituted carbazole-1-carboxamides were potent and selective inhibitors of Janus kinase 2 (JAK2).

Chitinases of the avian malaria parasite Plasmodium gallinaceum, a class of enzymes necessary for parasite invasion of the mosquito midgut.

PubMed

Vinetz, J M; Valenzuela, J G; Specht, C A; Aravind, L; Langer, R C; Ribeiro, J M; Kaslow, D C

2000-04-07

The Plasmodium ookinete produces chitinolytic activity that allows the parasite to penetrate the chitin-containing peritrophic matrix surrounding the blood meal in the mosquito midgut. Since the peritrophic matrix is a physical barrier that the parasite must cross to invade the mosquito, and the presence of allosamidin, a chitinase inhibitor, in a blood meal prevents the parasite from invading the midgut epithelium, chitinases (3.2.1.14) are potential targets of malaria parasite transmission-blocking interventions. We have purified a chitinase of the avian malaria parasite Plasmodium gallinaceum and cloned the gene, PgCHT1, encoding it. PgCHT1 encodes catalytic and substrate-binding sites characteristic of family 18 glycohydrolases. Expressed in Escherichia coli strain AD494 (DE3), recombinant PgCHT1 was found to hydrolyze polymeric chitin, native chitin oligosaccharides, and 4-methylumbelliferone derivatives of chitin oligosaccharides. Allosamidin inhibited recombinant PgCHT1 with an IC(50) of 7 microM and differentially inhibited two chromatographically separable P. gallinaceum ookinete-produced chitinase activities with IC(50) values of 7 and 12 microM, respectively. These two chitinase activities also had different pH activity profiles. These data suggest that the P. gallinaceum ookinete uses products of more than one chitinase gene to initiate mosquito midgut invasion.

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

PubMed

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

2011-01-01

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

Hyaluronan Does Not Regulate Human Epidermal Keratinocyte Proliferation and Differentiation*

PubMed Central

Malaisse, Jérémy; Pendaries, Valérie; Hontoir, Fanny; De Glas, Valérie; Van Vlaender, Daniel; Simon, Michel; Lambert de Rouvroit, Catherine; Poumay, Yves; Flamion, Bruno

2016-01-01

Hyaluronan (HA) is synthesized by three HA synthases (HAS1, HAS2, and HAS3) and secreted in the extracellular matrix. In human skin, large amounts of HA are found in the dermis. HA is also synthesized by keratinocytes in the epidermis, although its epidermal functions are not clearly identified yet. To investigate HA functions, we studied the effects of HA depletion on human keratinocyte physiology within in vitro reconstructed human epidermis. Inhibition of HA synthesis with 4-methylumbelliferone (4MU) did not modify the expression profile of the epidermal differentiation markers involucrin, keratin 10, and filaggrin during tissue reconstruction. In contrast, when keratinocytes were incubated with 4MU, cell proliferation was decreased. In an attempt to rescue the proliferation function, HA samples of various mean molecular masses were added to keratinocyte cultures treated with 4MU. These samples were unable to rescue the initial proliferation rate. Furthermore, treatments with HA-specific hyaluronidase, although removing almost all HA from keratinocyte cultures, did not alter the differentiation or proliferation processes. The differences between 4MU and hyaluronidase effects did not result from differences in intracellular HA, sulfated glycosaminoglycan concentration, apoptosis, or levels of HA receptors, all of which remained unchanged. Similarly, knockdown of UDP-glucose 6-dehydrogenase (UGDH) using lentiviral shRNA effectively decreased HA production but did not affect proliferation rate. Overall, these data suggest that HA levels in the human epidermis are not directly correlated with keratinocyte proliferation and differentiation and that incubation of cells with 4MU cannot equate with HA removal. PMID:26627828

Fluorescent microplate assay method for high-throughput detection of lipase transesterification activity.

PubMed

Zheng, Jianyong; Wei, Wei; Lan, Xing; Zhang, Yinjun; Wang, Zhao

2018-05-15

This study describes a sensitive and fluorescent microplate assay method to detect lipase transesterification activity. Lipase-catalyzed transesterification between butyryl 4-methyl umbelliferone (Bu-4-Mu) and methanol in tert-butanol was selected as the model reaction. The release of 4-methylumbelliferone (4-Mu) in the reaction was determined by detecting the fluorescence intensity at λ ex 330 nm and λ em 390 nm. Several lipases were used to investigate the accuracy and efficiency of the proposed method. Apparent Michaelis constant (Km) was calculated for transesterification between Bu-4-Mu and methanol by the lipases. The main advantages of the assay method include high sensitivity, inexpensive reagents, and simple detection process. Copyright © 2018 Elsevier Inc. All rights reserved.

Activity of influenza C virus O-acetylesterase with O-acetyl-containing compounds.

PubMed Central

Garcia-Sastre, A; Villar, E; Manuguerra, J C; Hannoun, C; Cabezas, J A

1991-01-01

Influenza C virus (strain C/Johannesburg/1/66) was grown, harvested, purified and used as source for the enzyme O-acetylesterase (N-acyl-O-acetylneuraminate O-acetylhydrolase; EC 3.1.1.53). This activity was studied and characterized with regard to some new substrates. The pH optimum of the enzyme is around 7.6, its stability at different pH values shows a result similar to that of the pH optimum, and its activity is well maintained in the pH range from 7.0 to 8.5 (all these tests were performed with 4-nitrophenyl acetate as substrate). Remarkable differences were found in the values of both Km and Vmax, with the synthetic substrates 4-nitrophenyl acetate, 2-nitrophenyl acetate, 4-methylumbelliferyl acetate, 1-naphthyl acetate and fluorescein diacetate. The use of 4-nitrophenyl acetate, 4-methylumbelliferyl acetate or 1-naphthyl acetate as substrate seems to be convenient for routine work, but it is better to carry out the measurements in parallel with those on bovine submandibular gland mucin (the latter is a natural and commercially available substrate). It was found that 4-acetoxybenzoic acid, as well as the methyl ester of 2-acetoxybenzoic acid, but not 2-acetoxybenzoic acid itself, are cleaved by this enzyme. Triacetin, di-O-acetyladenosine, tri-O-acetyladenosine, and di-O-acetyl-N-acetyladenosine phosphate, hitherto unreported as substrates for this viral esterase, are hydrolysed at different rates by this enzyme. We conclude that the O-acetylesterase from influenza C virus has a broad specificity towards both synthetic and natural non-sialic acid-containing substrates. Zn2+, Mn2+ and Pb2+ (as their chloride salts), N-acetylneuraminic acid, 4-methyl-umbelliferone and 2-acetoxybenzoic acid (acetylsalicylic acid) did not act as inhibitors. Images Fig. 1. PMID:1991039

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

PubMed

Yang, You; Li, Yao; Yu, Biao

2009-09-02

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

Screening glycosynthase libraries with a fluoride chemosensor assay independently of enzyme specificity: identification of a transitional hydrolase to synthase mutant.

PubMed

Andrés, Eduardo; Aragunde, Hugo; Planas, Antoni

2014-03-01

Glycosynthases have become efficient tools for the enzymatic synthesis of oligosaccharides, glycoconjugates and polysaccharides. Enzyme-directed evolution approaches are applied to improve the performance of current glycosynthases and engineer specificity for non-natural substrates. However, simple and general screening methods are required since most of the reported assays are specific for each particular enzyme. In the present paper, we report a general screening assay that is independent of enzyme specificity, and implemented in an HTS (high-throughput screening) format for the screening of cell extracts in directed evolution experiments. Fluoride ion is a general by-product released in all glycosynthase reactions with glycosyl fluoride donors. The new assay is based on the use of a specific chemical sensor (a silyl ether of a fluorogenic methylumbelliferone) to transduce fluoride concentration into a fluorescence signal. As a proof-of-concept, it has been applied to a nucleophile saturation mutant library of Bacillus licheniformis 1,3-1,4-β-glucanase. Beyond the expected mutations at the glutamic acid (catalytic) nucleophile, other variants have been shown to acquire glycosynthase activity. Surprisingly, an aspartic acid for glutamic acid replacement renders a highly active glycosynthase, but still retains low hydrolase activity. It appears as an intermediate state between glycosyl hydrolase and glycosynthase.

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

PubMed

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

2011-10-13

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

Peritoneal dialysis solution attenuates microvascular leukocyte adhesion induced by nitric oxide synthesis inhibition.

PubMed

White, R; Ram, S

1996-01-01

In the mesenteric microcirculation, inhibition of nitric oxide (NO) synthesis results in an inflammatory response through increased leukocyte adherence to the microvascular postcapillary venular endothelium. Recent studies have demonstrated that elevated concentrations of endogenous NO synthesis inhibitors are present in renal failure. How peritoneal dialysis solutions may affect leukocyte-endothelial interactions during inflammation induced by NO synthesis inhibition has been previously unknown. Using in vivo intravital microscopy of the rat mesenteric postcapillary venules, microvascular leukocyte adherence was quantitated during baseline conditions in which the mesentery was superfused with a buffer solution, followed by the superfusion of a NO synthesis inhibitor NG-nitro-L-ARGININE methyl ester (L-NAME) added to the buffer, followed by 4.25% Dianeal (4.25% D). When compared to baseline, L-NAME increased the mean number of adherent leukocytes by fivefold (2.2 +/- 0.9 vs 11.6 +/- 3.6 leukocytes/100 microns venule/10 min, p < 0.05), while 4.25% D quickly reversed the L-NAME-induced inflammatory response, returning the number of adherent leukocytes back to baseline values (11.6 +/- 3.6 vs 2.4 +/- 1.3 leukocytes/100 microns venule/ 10 min, p < 0.05). These results confirm that NO synthesis inhibition induces inflammation in mesenteric postcapillary venules. Superfusion of 4.25% D reverses leukocyte adhesion induced by NO synthesis inhibition. Thus, a standard peritoneal dialysis solution (4.25% D) reverses the leukocyte-adhesive effects of NO synthesis inhibition in the mesenteric microcirculation.

Synthesis and biological evaluation of novel quinazoline-4-piperidinesulfamide derivatives as inhibitors of NPP1.

PubMed

Forcellini, Elsa; Boutin, Sophie; Lefebvre, Carole-Anne; Shayhidin, Elnur Elyar; Boulanger, Marie-Chloé; Rhéaume, Gabrielle; Barbeau, Xavier; Lagüe, Patrick; Mathieu, Patrick; Paquin, Jean-François

2018-03-10

The ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) was recently shown to promote mineralization of the aortic valve, hence, its inhibition represents a significant target. A quinazoline-4-piperidine sulfamide compound (QPS1) has been described as a specific and non-competitive inhibitor of NPP1. We report herein the synthesis and in vitro inhibition studies of novel quinazoline-4-piperidine sulfamide analogues using QPS1 as the lead compound. Of the 26 derivatives prepared, four compounds were found to have K i  < 105 nM against human NPP1. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Synthesis and in vitro evaluation of 7-methoxy-N-(pent-4-enyl)-1,2,3,4-tetrahydroacridin-9-amine-new tacrine derivate with cholinergic properties.

PubMed

Korabecny, Jan; Musilek, Kamil; Zemek, Filip; Horova, Anna; Holas, Ondrej; Nepovimova, Eugenie; Opletalova, Veronika; Hroudova, Jana; Fisar, Zdenek; Jung, Young-Sik; Kuca, Kamil

2011-11-01

Cholinesterase inhibitors are, so far, the only successful strategy for the symptomatic treatment of Alzheimer's disease. Tacrine (THA) is a potent acetylcholinesterase inhibitor that was used in the treatment of Alzheimer's disease for a long time. However, the clinical use of THA was hampered by its low therapeutic index, short half-life and liver toxicity. 7-Methoxytacrine (7-MEOTA) is equally pharmacological active compound with lower toxicity compared to THA. In this Letter, the synthesis, biological activity and molecular modelling of elimination by-product isolated during synthesis of 7-MEOTA based bis-alkylene linked compound is described. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ectophosphatase activity in Candida albicans influences fungal adhesion: study between HIV-positive and HIV-negative isolates.

PubMed

Portela, M B; Kneipp, L F; Ribeiro de Souza, I P; Holandino, C; Alviano, C S; Meyer-Fernandes, J R; de Araújo Soares, R M

2010-07-01

This study describes the expression of acidic ectophosphatase activity on twenty isolates of C. albicans from oral cavities of HIV-infected children (HIV+) and compares them with fifteen isolates from HIV-negative children (HIV-), as well as the fungal adhesion to epithelial cells and medical records. The activities were measured in intact cells grown in BHI medium for 48 h at 37 degrees C. Phosphatase activity was assayed at pH 5.5 using 4-methylumbelliferyl phosphate. Yeast adhesion was measured using the MA 104 epithelial cell line. Mean values of ectophosphatase activity were 610.27 +/- 166.36 and 241.25 +/- 78.96 picomoles 4-methylumbelliferone/h/10(7) cells for HIV+ and HIV- group, respectively (P = 0.049). No correlation between C. albicans enzyme activity from HIV children with viral load and CD4 percentual was observed. Yeasts with high enzyme activity, isolated from HIV+ children showed greater adherence than yeasts with basal levels of ectophosphatases from HIV- (Spearman correlation, r = 0.8). Surface phosphatase activity was apparently involved in the adhesion to host cells, as the enhanced attachment of C. albicans to host epithelial cells was reversed by pretreatment of yeast with sodium orthovanadate (1 mM), an acid phosphatase inhibitor. These results show that C. albicans from HIV+ has an ectophosphatase activity significantly higher than the other isolates. Yeasts expressing higher levels of surface phosphatase activity showed greater adhesion to epithelial cells. So, the activity of acidic surface phosphatases on these cells may contribute to the early mechanisms required for disease establishment.

Synthesis of a Biologically Active Oxazol-5-(4H)-One via an Erlenmeyer-Plo¨chl Reaction

ERIC Educational Resources Information Center

Rodrigues, Catarina A. B.; Martinho, Jose´ M. G.; Afonso, Carlos A. M.

2015-01-01

The synthesis of (Z)-4-(4-nitrobenzylidene)-2- phenyloxazol-5(4"H")-one, which is a potent immunomodulator and tyrosinase inhibitor, is described as an experiment for an upper-division undergraduate organic chemistry laboratory course. This compound is produced via an Erlenmeyer-Plo¨chl reaction in the absence of any additional solvents…

Synthesis and evaluation of 5-(arylthio)-9H-pyrimido[4,5-b]indole-2,4-diamines as receptor tyrosine kinase and thymidylate synthase inhibitors and as antitumor agents.

PubMed

Zaware, Nilesh; Kisliuk, Roy; Bastian, Anja; Ihnat, Michael A; Gangjee, Aleem

2017-04-01

In an effort to optimize the structural requirements for combined cytostatic and cytotoxic effects in single agents, a series of 5-(arylthio)-9H-pyrimido[4,5-b]indole-2,4-diamines 3-7 were synthesized and evaluated as inhibitors of receptor tyrosine kinases (RTKs) as well as thymidylate synthase (TS). The synthesis of these compounds involved the nucleophilic displacement of the common intermediate 5-bromo/5-chloro-9H-pyrimido[4,5-b]indole-2,4-diamine with appropriate aryl thiols. A novel four step synthetic scheme to the common intermediate was developed which is more efficient relative to the previously reported six-step sequence. Biological evaluation of these compounds indicated dual activity in RTKs and human TS (hTS). In the VEGFR-2 assay, compound 5 was equipotent to the standard compound semaxanib and was better than standard TS inhibitor pemetrexed, in the hTS assay. Compounds 3, 6 and 7 were nanomolar inhibitors of hTS and were several fold better than pemetrexed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Flavonoids such as luteolin, fisetin and apigenin are inhibitors of interleukin-4 and interleukin-13 production by activated human basophils.

PubMed

Hirano, Toru; Higa, Shinji; Arimitsu, Junsuke; Naka, Tetsuji; Shima, Yoshihito; Ohshima, Shiro; Fujimoto, Minoru; Yamadori, Tomoki; Kawase, Ichiro; Tanaka, Toshio

2004-06-01

We have previously shown that fisetin, a flavonol, inhibits IL-4 and IL-13 synthesis by allergen- or anti-IgE-antibody-stimulated basophils. This time, we investigated the inhibition of IL-4 and IL-13 production by basophils by other flavonoids and attempted to determine the fundamental structure of flavonoids related to inhibition. We additionally investigated whether flavonoids suppress leukotriene C4 synthesis by basophils and IL-4 synthesis by T cells in response to anti-CD3 antibody. Highly purified peripheral basophils were stimulated for 12 h with anti-IgE antibody alone or anti-IgE antibody plus IL-3 in the presence of various concentrations of 18 different kinds of flavones and flavonols. IL-4 and IL-13 concentrations in the supernatants were then measured. Leukotriene C4 synthesis was also measured after basophils were stimulated for 1 h in the presence of flavonoids. Regarding the inhibitory activity of flavonoids on IL-4 synthesis by T cells, peripheral blood mononuclear cells were cultured with flavonoids in anti-CD3-antibody-bound plates for 2 days. Luteolin, fisetin and apigenin were found to be the strongest inhibitors of both IL-4 and IL-13 production by basophils but did not affect leukotriene C4 synthesis. At higher concentrations, these flavonoids suppressed IL-4 production by T cells. Based on a hierarchy of inhibitory activity, the basic structure for IL-4 inhibition by basophils was determined. Due to the inhibitory activity of flavonoids on IL-4 and IL-13 synthesis, it can be expected that the intake of flavonoids, depending on the quantity and quality, may ameliorate allergic symptoms or prevent the onset of allergic diseases. Copyright 2004 S. Karger AG, Basel

Discovery of Novel Tricyclic Heterocycles as Potent and Selective DPP-4 Inhibitors for the Treatment of Type 2 Diabetes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Wen-Lian; Hao, Jinsong; Domalski, Martin

In our efforts to develop second generation DPP-4 inhibitors, we endeavored to identify distinct structures with long-acting (once weekly) potential. Taking advantage of X-ray cocrystal structures of sitagliptin and other DPP-4 inhibitors, such as alogliptin and linagliptin bound to DPP-4, and aided by molecular modeling, we designed several series of heterocyclic compounds as initial targets. During their synthesis, an unexpected chemical transformation provided a novel tricyclic scaffold that was beyond our original design. Capitalizing on this serendipitous discovery, we have elaborated this scaffold into a very potent and selective DPP-4 inhibitor lead series, as highlighted by compound 17c.

Synthesis and Biochemical Evaluation of Thiochromanone Thiosemicarbazone Analogues as Inhibitors of Cathepsin L

PubMed Central

2012-01-01

A series of 36 thiosemicarbazone analogues containing the thiochromanone molecular scaffold functionalized primarily at the C-6 position were prepared by chemical synthesis and evaluated as inhibitors of cathepsins L and B. The most promising inhibitors from this group are selective for cathepsin L and demonstrate IC50 values in the low nanomolar range. In nearly all cases, the thiochromanone sulfide analogues show superior inhibition of cathepsin L as compared to their corresponding thiochromanone sulfone derivatives. Without exception, the compounds evaluated were inactive (IC50 > 10000 nM) against cathepsin B. The most potent inhibitor (IC50 = 46 nM) of cathepsin L proved to be the 6,7-difluoro analogue 4. This small library of compounds significantly expands the structure–activity relationship known for small molecule, nonpeptidic inhibitors of cathepsin L. PMID:24900494

11β-Hydoxylase Inhibitors Protect Against Seizures in Mice by Increasing Endogenous Neurosteroid Synthesis

PubMed Central

Kaminski, Rafal M.; Rogawski, Michael A.

2011-01-01

Steroid 11β-hydroxylase (CYP11B1; EC 1.14.15.4) is a mitochondrial enzyme located in the zona fasciculata of the adrenal cortex and also in the brain that mediates the conversion of 11-deoxycortisol to cortisol and 11-deoxycorticosterone (DOC) to corticosterone. Inhibitors of CYP11B1, such as metyrapone and etomidate, reduce glucocorticoid synthesis and raise levels of DOC providing greater availability for metabolic conversion to the GABAA receptor modulating neurosteroid allotetrahydrodeoxycorticosterone (THDOC). Because THDOC is a potent anticonvulsant, it is plausible that CYP11B1 inhibitors could protect against seizures. Here we demonstrate that metyrapone affords dose-dependent protection against 6-Hz seizures 30 min after injection (ED50, 191 mg/kg), but is markedly more potent at 6 h (ED50, 30 mg/kg). Similarly, etomidate is also protective at 30 min and 6 h (ED50 values, 4.5 and 1.7 mg/kg). Finasteride, an inhibitor of neurosteroid synthesis, attenuated the anticonvulsant effects of both CYP11B1 inhibitors at 6 h, but not 30 min following their injection. Plasma THDOC levels measured by liquid chromatography-mass spectrometry were markedly increased 6 h after injection of both CYP11B1 inhibitors and this increase was attenuated by finasteride pretreatment. We conclude that inhibition of CYP11B1 causes delayed seizure protection due to slow build-up of neurosteroids. Early seizure protection is independent of neurosteroids. PMID:21458468

Diagnosis of Morquio Syndrome in Dried Blood Spots Based on a New MRM-MS Assay.

PubMed

Cozma, Claudia; Eichler, Sabrina; Wittmann, Gyula; Flores Bonet, Alba; Kramp, Guido Johannes; Giese, Anne-Katrin; Rolfs, Arndt

2015-01-01

Mucopolysaccharidosis IVA (MPS IVA; Morquio A disease) is an autosomal recessive disease caused and characterized by a decreased activity of N-acetylgalactosamine-6-sulfate sulfatase (GALNS), resulting in accumulation of keratan sulfate and chondroitin-6-sulfate in tissues and secondary organ damage. Recently approved enzyme replacement therapy renders the easy and early identification of MPS IVA of out-most importance. We propose a completely new assay for the stable and reproducible detection of GALNS deficiency in dry blood spots (DBS). For the validation blood samples were taken from 59 healthy individuals and 24 randomly selected genetically confirmed MPS IVA patients. The material extracted from DBS was incubated with a 4-methylumbelliferyl-β-D-galactopyranoside-6-sulfate as a specific substrate. Final enzymatic product, 4-methylumbelliferone, obtained after adding exogenous beta-galactosidase, was quantified by LC/MRM-MS (liquid-chromatography/multiple-reaction-monitoring mass-spectrometry). 4-propyl-5-hydroxy-7-methyl-2h-chromen-2-one was used as internal standard, a compound with a similar molecular structure and fragmentation pattern in negative ion mode as 4-methylumbelliferone. The enzymatic assay yielded a positive and negative predictive value of 1.0 for genetically confirmed MPS IVA patients (GALNS activity of 0.35 ± 0.21 μmol/L/h) and for controls with normal GALNS activity (23.1 ± 5.3 μmol/L /h). With present enzymatic conditions, the reaction yield in dried blood spots is at least 20 fold higher than any previously reported data with other assays. The present LC/MRM-MS based assay for MPS IVA diagnosis provides an easy, highly-standardized, accurate and innovative quantification of the enzymatic product in vitro and distinguishes perfectly between MPS IVA affected patients and normal controls. This technique will significantly simplify the early detection of MPS IVA patients.

Adipocyte fatty acid binding protein 4 (FABP4) inhibitors. A comprehensive systematic review.

PubMed

Floresta, Giuseppe; Pistarà, Venerando; Amata, Emanuele; Dichiara, Maria; Marrazzo, Agostino; Prezzavento, Orazio; Rescifina, Antonio

2017-09-29

Small molecule inhibitors of adipocyte fatty acid binding protein 4 (FABP4) have attracted interest following the recent publications of beneficial pharmacological effects of these compounds. FABP4 is predominantly expressed in macrophages and adipose tissue where it regulates fatty acids (FAs) storage and lipolysis and is an important mediator of inflammation. In the past years, hundreds FABP4 inhibitors have been synthesized for effective atherosclerosis and diabetes treatments, including derivatives of niacin, quinoxaline, aryl-quinoline, bicyclic pyridine, urea, aromatic compounds and other novel heterocyclic compounds. This review provides an overview of the synthesized and discovered molecules as adipocyte fatty acid binding protein 4 inhibitors (FABP4is) since the synthesis of the putative FABP4i, BMS309403, highlighting the interactions of the different classes of inhibitors with the targets. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

PubMed

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

2012-11-01

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

Phosphodiesterase inhibitors. Part 6: design, synthesis, and structure-activity relationships of PDE4-inhibitory pyrazolo[1,5-a]pyridines with anti-inflammatory activity.

PubMed

Kojima, Akihiko; Takita, Satoshi; Sumiya, Tatsunobu; Ochiai, Koji; Iwase, Kazuhiko; Kishi, Tetsuya; Ohinata, Akira; Yageta, Yuichi; Yasue, Tokutaro; Kohno, Yasushi

2013-10-01

We previously identified KCA-1490 [(-)-6-(7-methoxy-2-trifluoromethyl-pyrazolo[1,5-a]pyridin-4-yl)-5-methyl-4,5-dihydro-3-(2H)-pyridazinone], a dual PDE3/4 inhibitor. In the present study, we found highly potent selective PDE4 inhibitors derived from the structure of KCA-1490. Among them, N-(3,5-dichloropyridin-4-yl)-7-methoxy-2-(trifluoromethyl)pyrazolo[1,5-a]pyridine-4-carboxamide (2a) had good anti-inflammatory effects in an animal model. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fully automated synthesis of 4-[18F]fluorobenzylamine based on borohydride/NiCl2 reduction.

PubMed

Way, Jenilee; Wuest, Frank

2013-04-01

4-[(18)F]Fluorobenzylamine ([(18)F]FBA) is an important building block for the synthesis of (18)F-labeled compounds. Synthesis of [(18)F]FBA usually involves application of strong reducing agents like LiAlH4 which is challenging to handle in automated synthesis units (ASUs). Therefore, alternative methods for the preparation of [(18)F]FBA compatible with remotely-controlled syntheses in ASUs are needed. (18)F]FBA was prepared in a remotely-controlled synthesis unit (GE TRACERlab™ FX) based on Ni(II)-mediated borohydride exchange resin (BER) reduction of 4-[(18)F]fluorobenzonitrile ([(18)F]FBN). [(18)F]FBA was used for the synthesis of novel thiol-reactive prosthetic group 4-[(18)F]fluorobenzyl)maleimide [(18)F]FBM and Hsp90 inhibitor 17-(4-[(18)F]fluorobenzylamino)-17-demethoxy-geldanamycin [(18)F] GA. [(18)F]FBA could be prepared in high radiochemical yield greater than 80% (decay-corrected) within 60min. In a typical experiment, 7.4GBq of [(18)F]FBA could be obtained in high radiochemical purity of greater than 95% starting from 10GBq of cyclotron-produced n.c.a. [(18)F]fluoride. [(18)F]FBA was used for the preparation of 4-[(18)F]fluorobenzyl)maleimide as a novel prosthetic group for labeling of thiol groups as demonstrated with tripeptide glutathione. [(18)F]FBA was also used as building block for the syntheses of small molecules as exemplified by the preparation of Hsp90 inhibitor 17-(4-[(18)F]fluorobenzylamino)-17-demethoxy-geldanamycin. The described remotely-controlled synthesis of [(18)F]FBA will significantly improve the availability of [(18)F]FBA as an important and versatile building block for the development of novel (18)F-labeled compounds containing a fluorobenzylamine moiety. Copyright © 2013 Elsevier Inc. All rights reserved.

Docking, synthesis and pharmacological activity of novel urea-derivatives designed as p38 MAPK inhibitors.

PubMed

de Oliveira Lopes, Raquel; Romeiro, Nelilma Correia; de Lima, Cleverton Kleiton F; Louback da Silva, Leandro; de Miranda, Ana Luisa Palhares; Nascimento, Paulo Gustavo B D; Cunha, Fernando Q; Barreiro, Eliezer J; Lima, Lídia Moreira

2012-08-01

p38 mitogen-activated protein kinase (p38 MAPK) is an important signal transducing enzyme involved in many cellular regulations, including signaling pathways, pain and inflammation. Several p38 MAPK inhibitors have been developed as drug candidates to treatment of autoimmune disorders, such as rheumatoid arthritis. In this paper we reported the docking, synthesis and pharmacological activity of novel urea-derivatives (4a-e) designed as p38 MAPK inhibitors. These derivatives presented good theoretical affinity to the target p38 MAPK, standing out compound 4e (LASSBio-998), which showed a better score value compared to the prototype GK-00687. This compound was able to reduce in vitro TNF-α production and was orally active in a hypernociceptive murine model sensible to p38 MAPK inhibitors. Otherwise, compound 4e presented a dose-dependent analgesic effect in a model of antigen (mBSA)-induced arthritis and anti-inflammatory profile in carrageenan induced paw edema, indicating its potential as a new antiarthritis prototype. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Synthesis and SAR of piperazine amides as novel c-jun N-terminal kinase (JNK) inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Youseung; Chen, Weiming; Habel, Jeff

2009-09-14

A novel series of c-jun N-terminal kinase (JNK) inhibitors were designed and developed from a high-throughput-screening hit. Through the optimization of the piperazine amide 1, several potent compounds were discovered. The X-ray crystal structure of 4g showed a unique binding mode different from other well known JNK3 inhibitors.

Regulation of nucleic acid and protein synthesis: a background study related to the biological effects of radiation. Final report on research activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The existence of an intricate interplay of nucleic acids and nucleotides in the chain of events leading from free amino acid to completed polypeptide chain has been determined. To this was added another participant to the nucleotides in protein synthesis - diadenosine-5', 5''', p'p/sup 4/-tetraphosphate (Ap4A). Ap/sub 4/A serves as an initiation primer for DNA synthesis in a eukaryotic system catalyzed by DNA polymerase ..cap alpha... Thus the initial step in protein synthesis is linked to the first step in DNA synthesis by a small molecular weight, unique dinucleotide signal. Advances in the methodology of nucleic acid sequencing have mademore » it possible to examine the relationship between specific short segments of DNA and RNA and their function in the metabolism of the living cell. The triester method of synthesizing deoxynucleotide polymers has made it feasible to synthesize and use specific oligomeric deoxynucleotide sequences as probes of genetic function and potential viral inhibitors. The synthesis of ribonucleotide polymers has been more difficult, due almost entirely to the presence of the 2' ribosyl hydroxyl group. The possibility is now emerging, however, of employing ribonucleotide polymers as specific RNA-virus inhibitors.« less

Interleukin-1 beta induced synthesis of protein kinase C-delta and protein kinase C-epsilon in EL4 thymoma cells: possible involvement of phosphatidylinositol 3-kinase.

PubMed

Varley, C L; Royds, J A; Brown, B L; Dobson, P R

2001-01-01

We present evidence here that the proinflammatory cytokine, interleukin-1 beta (IL-1 beta) stimulates a significant increase in protein kinase C (PKC)-epsilon and PKC-delta protein levels and increases PKC-epsilon, but not PKC-delta, transcripts in EL4 thymoma cells. Incubation of EL4 cells with IL-1 beta induced protein synthesis of PKC-epsilon (6-fold increase) by 7 h and had a biphasic effect on PKC-delta levels with peaks at 4 h (2-fold increase) and 24 h (4-fold increase). At the level of mRNA, PKC-epsilon, but not PKC-delta levels, were induced after incubation of EL4 cells with IL-1 beta. The signalling mechanisms utilized by IL-1 beta to induce the synthesis of these PKC isoforms were investigated. Two phosphatidylinositol (PI) 3-kinase-specific inhibitors, wortmannin and LY294002, inhibited IL-1 beta-induced synthesis of PKC-epsilon. However, the PI 3-kinase inhibitors had little effect on the IL-1 beta-induced synthesis of PKC-delta in these cells. Our results indicate that IL-1 beta induced both PKC-delta and PKC-epsilon expression over different time periods. Furthermore, our evidence suggests that IL-1 beta induction of PKC-epsilon, but not PKC-delta, may occur via the PI 3-kinase pathway. Copyright 2001 S. Karger AG, Basel

Synthesis and biological activities of new furo[3,4-b]carbazoles: potential topoisomerase II inhibitors.

PubMed

Hajbi, Youssef; Neagoie, Cléopatra; Biannic, Bérenger; Chilloux, Aurélie; Vedrenne, Emeline; Baldeyrou, Brigitte; Bailly, Christian; Mérour, Jean-Yves; Rosca, Sorin; Routier, Sylvain; Lansiaux, Amélie

2010-11-01

New 1,5-dihydro-4-(substituted phenyl)-3H-furo[3,4-b]carbazol-3-ones were synthesised via a key step Diels-Alder reaction under microwave irradiation. 3-Formylindole was successfully used in a 6-step synthesis to obtain those complex heterocycles. The Diels-Alder reaction generating the carbazole ring was optimised under thermal conditions or microwave irradiation. After cleavage of functional groups, DNA binding, topoisomerase inhibition and cytotoxic properties of the new-formed furocarbazoles were investigated. These carbazoles do not present a strong interaction with the DNA, and do not modify the relaxation of the DNA in the presence of topoisomerase I or II except for one promising compound. This compound is a potent topoisomerase II inhibitor, and its cellular activity is not moderated compared to etoposide. The synthesis of these molecules allowed the generalisation of the method using indole and 5-OBn indole and several benzaldehydes. The synthesis of these molecules produced chemical structures endowed with promising cytotoxic and topoisomerase II inhibition activities. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Novel fluorogenic probe for fluoride ion based on the fluoride-induced cleavage of tert-butyldimethylsilyl ether

NASA Astrophysics Data System (ADS)

Yang, Xiao-Feng

2007-06-01

A highly sensitive and selective fluorogenic probe for fluoride ion, 4-methylumbelliferyl tert-butyldimethylsilyl ether (4-MUTBS), was designed and synthesized. 4-MUTBS was a weakly fluorescent compound and was synthesized via the one-step reaction of 4-MU with tert-butyldimethylsilyl chloride. Upon incubation with fluoride ion in acetone-water solution (7:3, v/v), the Si-O bond of 4-MUTBS was cleaved and highly fluorescent 4-methylumbelliferone (4-MU) was released, hence leading to the fluorescence increase of the reaction solution. The fluorescence increase is linearly with fluoride concentration in the range 50-8000 nmol l -1 with a detection limit of 19 nmol l -1 (3 σ). Because of the high affinity of silicon toward fluoride ion, the proposed probe shows excellent selectivity toward fluoride ion over other anions. The method has been successfully applied to the fluoride determination in toothpaste and tap water samples.

Enzyme kinetics in acoustically levitated droplets of supercooled water: a novel approach to cryoenzymology.

PubMed

Weis, David D; Nardozzi, Jonathan D

2005-04-15

The rate of the alkaline phosphatase-catalyzed hydrolysis of 4-methylumbelliferone phosphate was measured in acoustically levitated droplets of aqueous tris (50 mM) at pH 8.5 at 22 +/- 2 degrees C and in supercooled solution at -6 +/- 2 degrees C. At 22 degrees C, the rate of product formation was in excellent agreement with the rate observed in bulk solution in a cuvette, indicating that the acoustic levitation process does not alter the enzyme activity. The rate of the reaction decreased 6-fold in supercooled solution at -6 +/- 2 degrees C. The acoustic levitator apparatus is described in detail.

Design and synthesis of chalcone derivatives as potential non-purine xanthine oxidase inhibitors.

PubMed

Bui, Trung Huu; Nguyen, Nhan Trung; Dang, Phu Hoang; Nguyen, Hai Xuan; Nguyen, Mai Thanh Thi

2016-01-01

Based on some previous research, the chalcone derivatives exhibited potent xanthine oxidase inhibitory activity, e.g. sappanchalcone ( 7 ), with IC 50 value of 3.9 μM, was isolated from Caesalpinia sappan . Therefore, objectives of this research are design and synthesis of 7 and other chalcone derivatives by Claisen-Schmidt condensation and then evaluate their XO inhibitory activity. Fifteen chalcone derivatives were synthesized by Claisen-Schmidt condensation, and were evaluated for XO inhibitory activity. Nine out of 15 synthetic chalcones showed inhibitory activity ( 3 ; 5 - 8 ; 10 - 13 ). Sappanchalcone derivatives ( 11 ) (IC 50 , 2.5 μM) and a novel chalcone ( 13 ) (IC 50 , 2.4 μM) displayed strong xanthine oxidase inhibitory activity that is comparable to allopurinol (IC 50 , 2.5 μM). The structure-activity relationship of these chalcone derivatives was also presented. It is the first research on synthesis sappanchalcone ( 7 ) by Claisen-Schmidt condensation. The overall yield of this procedure was 6.6 %, higher than that of reported procedure (4 %). Design, synthesis, and evaluation of chalcone derivatives were carried out. This result suggests that the chalcone derivative can be used as potential non-purine XO inhibitors.Graphical abstractThe chalcone derivatives as potential non-purine xanthine oxidase inhibitors.

Novel bioassay for the discovery of inhibitors of the 2-C-Methyl-D-Erythritol 4-Phosphate (MEP) and terpenoid pathways leading to carotenoid biosynthesis

USDA-ARS?s Scientific Manuscript database

The 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway leads to the synthesis of isopentenyl-phosphate (IPP) in plastids. It is a major branch point providing precursors for the synthesis of carotenoids, tocopherols, plastoquinone and the phytyl chain of chlorophylls, as well as the hormones abscisi...

Inhibition of hyaluronan synthesis in rats reduces renal ability to excrete fluid and electrolytes during acute hydration

PubMed Central

Stridh, Sara; Palm, Fredrik

2013-01-01

Background. Hyaluronan (HA) is the dominant glycosaminoglycan in the renomedullary interstitium. Renomedullary HA has been implicated in tubular fluid handling due to its water-attracting properties and the changes occurring in parallel to acute variations in the body hydration status. Methods. HA production was inhibited by 4-methylumbelliferone (4-MU in drinking water for 5 days, 1.45 ± 0.07 g/day/kg body weight) in rats prior to hydration. Results. Following hypotonic hydration for 135 min in control animals, diuresis and osmotic excretion increased while sodium excretion and glomerular filtration rate (GFR) remained unchanged. The medullary and cortical HA contents were 7.85 ± 1.29 ng/mg protein and 0.08 ± 0.01 ng/mg protein, respectively. Medullary HA content after 4-MU was 38% of that in controls (2.98 ± 0.95 ng/g protein, p < 0.05), while the low cortical levels were unaffected. Baseline urine flow was not different from that in controls. The diuretic response to hydration was, however, only 51% of that in controls (157 ± 36 versus 306 ± 54 µl/g kidney weight/135 min, p < 0.05) and the osmolar excretion only 47% of that in controls (174 ± 47 versus 374 ± 41 µOsm/g kidney weight/135 min, p < 0.05). Sodium excretion, GFR, and arterial blood pressure were similar to that in control rats and unaltered during hydration. Conclusions. Reduction of renomedullary interstitial HA using 4-MU reduces the ability of the kidney to respond appropriately upon acute hydration. The results strengthen the concept of renomedullary HA as a modulator of tubular fluid handling by changing the physicochemical properties of the interstitial space. PMID:24102146

Insulin promotes diacylglycerol kinase activation by different mechanisms in rat cerebral cortex synaptosomes.

PubMed

Zulian, Sandra E; Ilincheta de Boschero, Mónica G; Giusto, Norma M

2006-10-01

The mechanism by which insulin increases diacylglycerol kinase (DAGK) activity has been studied in cerebral cortex (CC) synaptosomes from adult (3-4 months of age) rats. The purpose of this study was to identify the role of phospholipases C and D (PLC and PLD) in DAGK activation by insulin. Neomycin, an inhibitor of PLC phosphatidylinositol-bisphosphate (PIP2) specific; ethanol, an inhibitor of phosphatidic acid (PA) formation by the promotion of a transphosphatidyl reaction of phosphatidylcholine phospholipase D (PC-PLD); and DL propranolol, an inhibitor of phosphatidate phosphohydrolase (PAP), were used in this study. Insulin (0.1 microM) shielded an increase in PA synthesis by [32P] incorporation using [gamma-32P]ATP as substrate and endogenous diacylglycerol (DAG) as co-substrate. This activated synthesis was strongly inhibited either by ethanol or DL propranolol. Pulse chase experiments also showed a PIP2-PLC activation within 1 min exposure to insulin. When exogenous unsaturated 18:0-20:4 DAG was present, insulin increased PA synthesis significantly. However, this stimulatory effect was not observed in the presence of exogenous saturated (di-16:0). In the presence of R59022, a selective DAGK inhibitor, insulin exerted no stimulatory effect on [32P]PA formation, suggesting a strong relationship between increased PA formation by insulin and DAGK activity. These data indicate that the increased synthesis of PA by insulin could be mediated by the activation of both a PC-PLD pathway to provide DAG and a direct DAGK activation that is associated to the use of 18:0-20:4 DAG species. PIP2-PLC activation may contribute at least partly to the insulin effect on DAGK activity. Copyright 2006 Wiley-Liss, Inc.

Design of HIV-1 Protease Inhibitors with Amino-bis-tetrahydrofuran Derivatives as P2-Ligands to Enhance Backbone-Binding Interactions. Synthesis, Biological Evaluation, and Protein-Ligand X-ray Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Arun K.; Martyr, Cuthbert D.; Osswald, Heather L.

Structure-based design, synthesis, and biological evaluation of a series of very potent HIV-1 protease inhibitors are described. In an effort to improve backbone ligand–binding site interactions, we have incorporated basic-amines at the C4 position of the bis-tetrahydrofuran (bis-THF) ring. We speculated that these substituents would make hydrogen bonding interactions in the flap region of HIV-1 protease. Synthesis of these inhibitors was performed diastereoselectively. A number of inhibitors displayed very potent enzyme inhibitory and antiviral activity. Inhibitors 25f, 25i, and 25j were evaluated against a number of highly-PI-resistant HIV-1 strains, and they exhibited improved antiviral activity over darunavir. Two high resolutionmore » X-ray structures of 25f- and 25g-bound HIV-1 protease revealed unique hydrogen bonding interactions with the backbone carbonyl group of Gly48 as well as with the backbone NH of Gly48 in the flap region of the enzyme active site. These ligand–binding site interactions are possibly responsible for their potent activity.« less

Comparison of Monoamine Oxidase Inhibitors in Decreasing Production of the Autotoxic Dopamine Metabolite 3,4-Dihydroxyphenylacetaldehyde in PC12 Cells

PubMed Central

Jinsmaa, Yunden; Sullivan, Patti; Holmes, Courtney; Kopin, Irwin J.; Sharabi, Yehonatan

2016-01-01

According to the catecholaldehyde hypothesis, the toxic dopamine metabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL) contributes to the loss of nigrostriatal dopaminergic neurons in Parkinson’s disease. Monoamine oxidase-A (MAO-A) catalyzes the conversion of intraneuronal dopamine to DOPAL and may serve as a therapeutic target. The “cheese effect”—paroxysmal hypertension evoked by tyramine-containing foodstuffs—limits clinical use of irreversible MAO-A inhibitors. Combined MAO-A/B inhibition decreases DOPAL production in rat pheochromocytoma PC12 cells, but whether reversible MAO-A inhibitors or MAO-B inhibitors decrease endogenous DOPAL production is unknown. We compared the potencies of MAO inhibitors in attenuating DOPAL production and examined possible secondary effects on dopamine storage, constitutive release, synthesis, and auto-oxidation. Catechol concentrations were measured in cells and medium after incubation with the irreversible MAO-A inhibitor clorgyline, three reversible MAO-A inhibitors, or the MAO-B inhibitors selegiline or rasagiline for 180 minutes. Reversible MAO-A inhibitors were generally ineffective, whereas clorgyline (1 nM), rasagiline (500 nM), and selegiline (500 nM) decreased DOPAL levels in the cells and medium. All three drugs also increased dopamine and norepinephrine, decreased 3,4-dihydroxyphenylalanine, and increased cysteinyl-dopamine concentrations in the medium, suggesting increased vesicular uptake and constitutive release, decreased dopamine synthesis, and increased dopamine spontaneous oxidation. In conclusion, clorgyline, rasagiline, and selegiline decrease production of endogenous DOPAL. At relatively high concentrations, the latter drugs probably lose their selectivity for MAO-B. Possibly offsetting increased formation of potentially toxic oxidation products and decreased formation of DOPAL might account for the failure of large clinical trials of MAO-B inhibitors to demonstrate slowing of neurodegeneration in Parkinson’s disease. PMID:26574516

Orally active achiral N-hydroxyformamide inhibitors of ADAM-TS4 (aggrecanase-1) and ADAM-TS5 (aggrecanase-2) for the treatment of osteoarthritis.

PubMed

De Savi, Chris; Pape, Andrew; Sawyer, Yvonne; Milne, David; Davies, Chris; Cumming, John G; Ting, Attilla; Lamont, Scott; Smith, Peter D; Tart, Jonathon; Page, Ken; Moore, Peter

2011-06-01

A new achiral class of N-hydroxyformamide inhibitor of both ADAM-TS4 and ADAM-TS5, 2 has been discovered through modification of the complex P1 group present in historical inhibitors 1. This structural change improved the DMPK properties and greatly simplified the synthesis whilst maintaining excellent cross-MMP selectivity profiles. Investigation of structure-activity and structure-property relationships in the P1 group resulted in both ADAM-TS4 selective and mixed ADAM-TS4/5 inhibitors. This led to the identification of a pre-clinical candidate with excellent bioavailability across three species and predicting once daily dosing kinetics. Copyright © 2011 Elsevier Ltd. All rights reserved.

Chemical Inactivation of the Cinnamate 4-Hydroxylase Allows for the Accumulation of Salicylic Acid in Elicited Cells1

PubMed Central

Schoch, Guillaume A.; Nikov, Georgi N.; Alworth, William L.; Werck-Reichhart, Danièle

2002-01-01

The cinnamate (CA) 4-hydroxylase (C4H) is a cytochrome P450 that catalyzes the second step of the main phenylpropanoid pathway, leading to the synthesis of lignin, pigments, and many defense molecules. Salicylic acid (SA) is an essential trigger of plant disease resistance. Some plant species can synthesize SA from CA by a mechanism not yet understood. A set of specific inhibitors of the C4H, including competitive, tight-binding, mechanism-based irreversible, and quasi-irreversible inhibitors have been developed with the main objective to redirect cinnamic acid to the synthesis of SA. Competitive inhibitors such as 2-hydroxy-1-naphthoic acid and the heme-coordinating compound 3-(4-pyridyl)-acrylic acid allowed strong inhibition of C4H activity in a tobacco (Nicotiana tabacum cv Bright Yellow [BY]) cell suspension culture. This inhibition was however rapidly relieved either because of substrate accumulation or because of inhibitor metabolism. Substrate analogs bearing a methylenedioxo function such as piperonylic acid (PIP) or a terminal acetylene such as 4-propynyloxybenzoic acid (4PB), 3-propynyloxybenzoic acid, and 4-propynyloxymethylbenzoic acid are potent mechanism-based inactivators of the C4H. PIP and 4PB, the best inactivators in vitro, were also efficient inhibitors of the enzyme in BY cells. Inhibition was not reversed 46 h after cell treatment. Cotreatment of BY cells with the fungal elicitor β-megaspermin and PIP or 4PB led to a dramatic increase in SA accumulation. PIP and 4PB do not trigger SA accumulation in nonelicited cells in which the SA biosynthetic pathway is not activated. Mechanism-based C4H inactivators, thus, are promising tools for the elucidation of the CA-derived SA biosynthetic pathway and for the potentiation of plant defense. PMID:12376665

DNA synthesis inhibitors for the treatment of gastrointestinal cancer.

PubMed

Yasui, Hiroshi; Tsurita, Giichiro; Imai, Kohzoh

2014-11-01

Intensive laboratory, preclinical and clinical studies have identified and validated molecular targets in cancers, leading to a shift toward the development of novel, rationally designed and specific therapeutic agents. However, gastrointestinal cancers continue to have a poor prognosis, largely due to drug resistance. Here, we discuss the current understanding of DNA synthesis inhibitors and their mechanisms of action for the treatment of gastrointestinal malignancies. Conventional agents, including DNA synthesis inhibitors such as fluoropyrimidines and platinum analogs, remain the most effective therapeutics and are the standards against which new drugs are compared. Novel DNA synthesis inhibitors for the treatment of gastrointestinal malignancies include a combination of the antimetabolite TAS-102, which consists of trifluorothymidine with a thymidine phosphorylase inhibitor, and a novel micellar formulation of cisplatin NC-6004 that uses a nanotechnology-based drug delivery system. The challenges of translational cancer research using DNA synthesis inhibitors include the identification of drugs that are specific to tumor cells to reduce toxicity and increase antitumor efficacy, biomarkers to predict pharmacological responses to chemotherapeutic drugs, identification of ways to overcome drug resistance and development of novel combination therapies with DNA synthesis inhibitors and other cancer therapies, such as targeted molecular therapeutics. Here, we discuss the current understanding of DNA synthesis inhibitors and their mechanisms of action for the treatment of gastrointestinal malignancies.

Synthesis and evaluation of 3,4-dihydropyrimidin-2(1H)-ones as sodium iodide symporter inhibitors.

PubMed

Lacotte, Pierre; Puente, Celine; Ambroise, Yves

2013-01-01

The sodium iodide symporter (NIS) is responsible for the accumulation of iodide in the thyroid gland. This transport process is involved in numerous thyroid dysfunctions and is the basis for human contamination in the case of exposure to radioactive iodine species. 4-Aryl-3,4-dihydropyrimidin-2(1H)-ones were recently discovered by high-throughput screening as the first NIS inhibitors. Described herein are the synthesis and evaluation of 115 derivatives with structural modifications at five key positions on the pyrimidone core. This study provides extensive structure-activity relationships for this new class of inhibitors that will serve as a basis for further development of compounds with in vivo efficacy and adequate pharmacokinetic properties. In addition, the SAR investigation provided a more potent compound, which exhibits an IC(50) value of 3.2 nM in a rat thyroid cell line (FRTL5). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure–Activity Relationships and Molecular Modeling of Sphingosine Kinase Inhibitors

PubMed Central

2013-01-01

The design, synthesis, and evaluation of the potency of new isoform-selective inhibitors of sphingosine kinases 1 and 2 (SK1 and SK2), the enzyme that catalyzes the phosphorylation of d-erythro-sphingosine to produce the key signaling lipid, sphingosine 1-phosphate, are described. Recently, we reported that 1-(4-octylphenethyl)piperidin-4-ol (RB-005) is a selective inhibitor of SK1. Here we report the synthesis of 43 new analogues of RB-005, in which the lipophilic tail, polar headgroup, and linker region were modified to extend the structure–activity relationship profile for this lead compound, which we explain using modeling studies with the recently published crystal structure of SK1. We provide a basis for the key residues targeted by our profiled series and provide further evidence for the ability to discriminate between the two isoforms using pharmacological intervention. PMID:24164513

4,4,4-trifluoro-3-(indole-3-)butyric acid promotes root elongation in Lactuca sativa independent of ethylene synthesis and pH

NASA Technical Reports Server (NTRS)

Zhang, Nenggang; Hasenstein, Karl H.

2002-01-01

We studied the mode of action of 4,4,4-trifluoro-3- (indole-3-) butyric acid (TFIBA), a recently described root growth stimulator, on primary root growth of Lactuca sativa L. seedlings. TFIBA (100 micromoles) promoted elongation of primary roots by 40% in 72 h but inhibited hypocotyl growth by 35%. TFIBA induced root growth was independent of pH. TFIBA did not affect ethylene production, but reduced the inhibitory effect of ethylene on root elongation. TFIBA promoted root growth even in the presence of the ethylene biosynthesis inhibitor L-alpha-(2-aminoethoxyvinyl)glycine. TFIBA and the ethylene-binding inhibitor silver thiosulphate (STS) had a similar effect on root elongation. The results indicate that TFIBA-stimulated root elongation was neither pH-dependent nor related to inhibition of ethylene synthesis, but was possibly related to ethylene action.

Function through bio-inspired, synthesis-informed design: step-economical syntheses of designed kinase inhibitors†Dedicated to Max Malacria, a friend and scholar whose science and creative contributions to step-economical synthesis have inspired us all and moved the field closer to the ideal.‡Electronic supplementary information (ESI) available: Synthetic procedures and spectral data. See DOI: 10.1039/c4qo00228hClick here for additional data file.

PubMed

Wender, Paul A; Axtman, Alison D; Golden, Jennifer E; Kee, Jung-Min; Sirois, Lauren E; Quiroz, Ryan V; Stevens, Matthew C

2014-12-29

The human kinome comprises over 500 protein kinases. When mutated or over-expressed, many play critical roles in abnormal cellular functions associated with cancer, cardiovascular disease and neurological disorders. Here we report a step-economical approach to designed kinase inhibitors inspired by the potent, but non-selective, natural product staurosporine, and synthetically enabled by a novel, complexity-increasing, serialized [5 + 2]/[4 + 2] cycloaddition strategy. This function-oriented synthesis approach rapidly affords tunable scaffolds, and produced a low nanomolar inhibitor of protein kinase C.

Novel fatty acid binding protein 4 (FABP4) inhibitors: virtual screening, synthesis and crystal structure determination.

PubMed

Cai, Haiyan; Liu, Qiufeng; Gao, Dingding; Wang, Ting; Chen, Tiantian; Yan, Guirui; Chen, Kaixian; Xu, Yechun; Wang, Heyao; Li, Yingxia; Zhu, Weiliang

2015-01-27

Fatty acid binding protein 4 (FABP4) is a potential drug target for diabetes and atherosclerosis. For discovering new chemical entities as FABP4 inhibitors, structure-based virtual screening (VS) was performed, bioassay demonstrated that 16 of 251 tested compounds are FABP4 inhibitors, among which compound m1 are more active than endogenous ligand linoleic acid (LA). Based on the structure of m1, new derivatives were designed and prepared, leading to the discovery of two more potent inhibitors, compounds 9 and 10. To further explore the binding mechanisms of these new inhibitors, we determined the X-ray structures of the complexes of FABP4-9 and FABP4-10, which revealed similar binding conformations of the two compounds. Residue Ser53 and Arg126 formed direct hydrogen bonding with the ligands. We also found that 10 could significantly reduce the levels of lipolysis on mouse 3T3-L1 adipocytes. Taken together, in silico, in vitro and crystallographic data provide useful hints for future development of novel inhibitors against FABP4. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Kinesin spindle protein (KSP) inhibitors. Part 3: synthesis and evaluation of phenolic 2,4-diaryl-2,5-dihydropyrroles with reduced hERG binding and employment of a phosphate prodrug strategy for aqueous solubility.

PubMed

Garbaccio, Robert M; Fraley, Mark E; Tasber, Edward S; Olson, Christy M; Hoffman, William F; Arrington, Kenneth L; Torrent, Maricel; Buser, Carolyn A; Walsh, Eileen S; Hamilton, Kelly; Schaber, Michael D; Fernandes, Christine; Lobell, Robert B; Tao, Weikang; South, Vicki J; Yan, Youwei; Kuo, Lawrence C; Prueksaritanont, Thomayant; Slaughter, Donald E; Shu, Cathy; Heimbrook, David C; Kohl, Nancy E; Huber, Hans E; Hartman, George D

2006-04-01

2,4-Diaryl-2,5-dihydropyrroles have been discovered to be novel, potent and water-soluble inhibitors of KSP, an emerging therapeutic target for the treatment of cancer. A potential concern for these basic KSP inhibitors (1 and 2) was hERG binding that can be minimized by incorporation of a potency-enhancing C2 phenol combined with neutral N1 side chains. Aqueous solubility was restored to these, and other, non-basic inhibitors, through a phosphate prodrug strategy.

Design, synthesis and activity as acid ceramidase inhibitors of 2-oxooctanoyl and N-oleoylethanolamine analogues.

PubMed

Grijalvo, Santiago; Bedia, Carmen; Triola, Gemma; Casas, Josefina; Llebaria, Amadeu; Teixidó, Jordi; Rabal, Obdulia; Levade, Thierry; Delgado, Antonio; Fabriàs, Gemma

2006-10-01

The synthesis of novel N-acylethanolamines and their use as inhibitors of the aCDase is reported here. The compounds are either 2-oxooctanamides or oleamides of sphingosine analogs featuring a 3-hydroxy-4,5-hexadecenyl tail replaced by ether or thioether moieties. It appears that, within the 2-oxooctanamide family, the C3-OH group of the sphingosine molecule is required for inhibition both in vitro and in cultured cells. Furthermore, although the (E)-4 double bond is not essential for inhibitory activity, the (E) configuration is required, since the analogue with a (Z)-4 unsaturation was not inhibitory. None of the oleamides inhibited the aCDase in vitro. Conversely, with the exception of N-oleoylethanolamine and its analogs with S-decyl and S-hexadecyl substituents, all the synthesized oleamides inhibited the aCDase in cultured cells, although with a relatively low potency. We conclude that novel aCDase inhibitors can evolve from N-acylation of sphingoid bases with electron deficient-acyl groups. In contrast, chemical modification of the N-oleoylsphingosine backbone does not seem to offer an appropriate strategy to obtain aCDase inhibitors.

Synthesis of 4-(5-iodo-3-methylpyrazolyl) phenylsulfonamide and its elaboration to a COX II inhibitor library by solution-phase suzuki coupling using Pd/C as a solid-supported catalyst.

PubMed

Organ, Michael G; Mayer, Stanislas

2003-01-01

An effective synthesis of 4-(5-iodo-3-methylpyrazolyl) phenylsulfonamide has been developed. This aromatic iodide template served as an efficient oxidative addition partner for the preparation of a solution-phase library of Celecoxib analogues via Suzuki coupling using Pd/C, a readily filterable catalyst.

Design, synthesis and biological evaluation of tetrahydronaphthyridine derivatives as bioavailable CDK4/6 inhibitors for cancer therapy.

PubMed

Zha, Chuantao; Deng, Wenjia; Fu, Yan; Tang, Shuai; Lan, Xiaojing; Ye, Yan; Su, Yi; Jiang, Lei; Chen, Yi; Huang, Ying; Ding, Jian; Geng, Meiyu; Huang, Min; Wan, Huixin

2018-03-25

CDK4/6 pathway is an attractive chemotherapeutic target for antitumor drug discovery and development. Herein, we reported the structure-based design and synthesis of a series of novel tetrahydronaphthyridine analogues as selective CDK4/6 inhibitors. Compound 5 was identified as a hit and then systematically structure optimization study was conducted. These efforts led to compound 28, which exhibited excellent in vitro potencies against CDK4/6 enzymatic activity with high selectivity over CDK1, and against Colo-205 cell growth. The compound demonstrated favorable in vitro metabolic and robust mice pharmacokinetic properties. In Colo-205 xenograft models, compound 28 showed potent tumor growth inhibition with acceptable toxic effects, which could serve as a novel anticancer agent for further preclinical study. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Synthesis, kinetic characterization and metabolism of diastereomeric 2-(1-(4-phenoxyphenylsulfonyl)ethyl)thiiranes as potent gelatinase and MT1-MMP inhibitors.

PubMed

Gooyit, Major; Lee, Mijoon; Hesek, Dusan; Boggess, Bill; Oliver, Allen G; Fridman, Rafael; Mobashery, Shahriar; Chang, Mayland

2009-12-01

Gelatinases (MMP-2 and MMP-9) have been implicated in a number of pathological conditions, including cancer and cardiovascular disease. Hence, small molecule inhibitors of these enzymes are highly sought for use as potential therapeutic agents. 2-(4-Phenoxyphenylsulfonylmethyl)thiirane (SB-3CT) has previously been demonstrated to be a potent and selective inhibitor of gelatinases, however, it is rapidly metabolized because of oxidation at the para position of the phenoxy ring and at the alpha-position to the sulfonyl group. alpha-Methyl variants of SB-3CT were conceived to improve metabolic stability and as mechanistic probes. We describe herein the synthesis and evaluation of these structural variants as potent inhibitors of gelatinases. Two (compounds 5b and 5d) among the four synthetic stereoisomers were found to exhibit slow-binding inhibition of gelatinases and MMP-14 (MT1-MMP), which is a hallmark of the mechanism of this class of inhibitors. The ability of these compounds to inhibit MMP-2, MMP-9, and MMP-14 could target cancer tissues more effectively. Metabolism of the newly synthesized inhibitors showed that both oxidation at the alpha-position to the sulfonyl group and oxidation at the para position of the terminal phenyl ring were prevented. Instead oxidation on the thiirane sulfur is the only biotransformation pathway observed for these gelatinase inhibitors.

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

PubMed

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

2002-11-18

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

Accumulation of Polyhydroxyalkanoic Acid Containing Large Amounts of Unsaturated Monomers in Pseudomonas fluorescens BM07 Utilizing Saccharides and Its Inhibition by 2-Bromooctanoic Acid

PubMed Central

Lee, Ho-Joo; Choi, Mun Hwan; Kim, Tae-Un; Yoon, Sung Chul

2001-01-01

A psychrotrophic bacterium, Pseudomonas fluorescens BM07, which is able to accumulate polyhydroxyalkanoic acid (PHA) containing large amounts of 3-hydroxy-cis-5-dodecenoate unit up to 35 mol% in the cell from unrelated substrates such as fructose, succinate, etc., was isolated from an activated sludge in a municipal wastewater treatment plant. When it was grown on heptanoic acid (C7) to hexadecanoic acid (C16) as the sole carbon source, the monomer compositional characteristics of the synthesized PHA were similar to those observed in other fluorescent pseudomonads belonging to rRNA homology group I. However, growth on stearic acid (C18) led to no PHA accumulation, but instead free stearic acid was stored in the cell. The existence of the linkage between fatty acid de novo synthesis and PHA synthesis was confirmed by using inhibitors such as acrylic acid and two other compounds, 2-bromooctanoic acid and 4-pentenoic acid, which are known to inhibit β-oxidation enzymes in animal cells. Acrylic acid completely inhibited PHA synthesis at a concentration of 4 mM in 40 mM octanoate-grown cells, but no inhibition of PHA synthesis occurred in 70 mM fructose-grown cells in the presence of 1 to 5 mM acrylic acid. 2-Bromooctanoic acid and 4-pentenoic acid were found to much inhibit PHA synthesis much more strongly in fructose-grown cells than in octanoate-grown cells over concentrations ranging from 1 to 5 mM. However, 2-bromooctanoic acid and 4-pentenoic acid did not inhibit cell growth at all in the fructose media. Especially, with the cells grown on fructose, 2-bromooctanoic acid exhibited a steep rise in the percent PHA synthesis inhibition over a small range of concentrations below 100 μM, a finding indicative of a very specific inhibition, whereas 4-pentenoic acid showed a broad, featureless concentration dependence, suggesting a rather nonspecific inhibition. The apparent inhibition constant Ki (the concentration for 50% inhibition of PHA synthesis) for 2-bromooctanoic acid was determined to be 60 μM, assuming a single-site binding of the inhibitor at a specific inhibition site. Thus, it seems likely that a coenzyme A thioester derivative of 2-bromooctanoic acid specifically inhibits an enzyme linking the two pathways, fatty acid de novo synthesis and PHA synthesis. We suggest that 2-bromooctanoic acid can substitute for the far more expensive (2,000 times) and cell-growth-inhibiting PHA synthesis inhibitor, cerulenin. PMID:11679314

Design and synthesis of dual inhibitors of acetylcholinesterase and serotonin transporter targeting potential agents for Alzheimer's disease.

PubMed

Kogen, Hiroshi; Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio

2002-10-03

Highly efficient acetylcholinesterase (AChE) and serotonin transporter (SERT) dual inhibitors, (S)-4 and (R)-13 were designed and synthesized on the basis of the hypothetical model of AChE active site. Both compounds showed potent inhibitory activities against AChE and SERT. [structure: see text

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

NASA Astrophysics Data System (ADS)

Negmeldin, Ahmed Thabet

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

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

NASA Astrophysics Data System (ADS)

Jha, Vibhu; Bhadoriya, Kamlendra Singh

2018-04-01

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

Phosphatase control of 4E-BP1 phosphorylation state is central for glycolytic regulation of retinal protein synthesis.

PubMed

Gardner, Thomas W; Abcouwer, Steven F; Losiewicz, Mandy K; Fort, Patrice E

2015-09-15

Control of protein synthesis in insulin-responsive tissues has been well characterized, but relatively little is known about how this process is regulated in nervous tissues. The retina exhibits a relatively high protein synthesis rate, coinciding with high basal Akt and metabolic activities, with the majority of retinal ATP being derived from aerobic glycolysis. We examined the dependency of retinal protein synthesis on the Akt-mTOR signaling and glycolysis using ex vivo rat retinas. Akt inhibitors significantly reduced retinal protein synthesis but did not affect glycolytic lactate production. Surprisingly, the glycolytic inhibitor 2-deoxyglucose (2-DG) markedly inhibited Akt1 and Akt3 activities, as well as protein synthesis. The effects of 2-DG, and 2-fluorodeoxyglucose (2-FDG) on retinal protein synthesis correlated with inhibition of lactate production and diminished ATP content, with all these effects reversed by provision of d-mannose. 2-DG treatment was not associated with increased AMPK, eEF2, or eIF2α phosphorylation; instead, it caused rapid dephosphorylation of 4E-BP1. 2-DG reduced total mTOR activity by 25%, but surprisingly, it did not reduce mTORC1 activity, as indicated by unaltered raptor-associated mTOR autophosphorylation and ribosomal protein S6 phosphorylation. Dephosphorylation of 4E-BP1 was largely prevented by inhibition of PP1/PP2A phosphatases with okadaic acid and calyculin A, and inhibition of PPM1 phosphatases with cadmium. Thus, inhibition of retinal glycolysis diminished Akt and protein synthesis coinciding with accelerated dephosphorylation of 4E-BP1 independently of mTORC1. These results demonstrate a novel mechanism regulating protein synthesis in the retina involving an mTORC1-independent and phosphatase-dependent regulation of 4E-BP1. Copyright © 2015 the American Physiological Society.

Synthesis of Novel Compounds as New Potent Tyrosinase Inhibitors

PubMed Central

Hamidian, Hooshang

2013-01-01

In the present paper, we report the synthesis and pharmacological evaluation of a new series of azo compounds with different groups (1-naphthol, 2-naphthol, and N,N-dimethylaniline) and trifluoromethoxy and fluoro substituents in the scaffold. All synthesized compounds (5a–5f) showed the most potent mushroom tyrosinase inhibition (IC50 values in the range of 4.39 ± 0.76–1.71 ± 0.49 µM), comparable to the kojic acid, as reference standard inhibitor. All the novel compounds were characterized by FT-IR, 1H NMR, 13C NMR, and elemental analysis. PMID:24260737

Pre-clinical pharmacology of ICI D2138, a potent orally-active non-redox inhibitor of 5-lipoxygenase.

PubMed Central

McMillan, R. M.; Spruce, K. E.; Crawley, G. C.; Walker, E. R.; Foster, S. J.

1992-01-01

1. This paper describes the pre-clinical pharmacology of ICI D2138, a potent orally-active non-redox inhibitor of 5-lipoxygenase which is undergoing clinical evaluation. 2. ICI D2138 potently inhibited leukotriene synthesis in murine peritoneal macrophages (IC50 = 3 nM) and human blood (IC50 = 20 nM). In human and dog blood, ICI D2138 did not inhibit thromboxane B2 synthesis at a concentration of 500 microM, thus the selectivity ratio (cyclo-oxygenase: 5-lipoxygenase) was greater than 20,000. In contrast, zileuton (a 5-lipoxygenase inhibitor also undergoing clinical evaluation) exhibited a selectivity ratio of 15-100. 3. ICI D2138 potently and dose-dependently inhibited ex vivo leukotriene B4 (LTB4) synthesis by rat blood with ED50 values of 0.9, 4.0 and 80.0 mg kg-1 p.o. at 3, 10 and 20 h respectively after dosing. Similar activity was observed for inhibition of LTB4 production in a zymosan-inflamed rat air pouch model. Zileuton produced ED50 values of 5 and 20 mg kg-1 at 3 and 10 h respectively. 4. Oral administration of 1, 3 or 10 mg kg-1 ICI D2138 to dogs produced maximal inhibition of ex vivo LTB4 synthesis by blood for 5, 9 and 31 h respectively. A dose of 5 mg kg-1 p.o. of zileuton caused maximal inhibition of LTB4 for 24 h. 5. Oral administration of 10 mg kg-1 ICI D2138 caused total inhibition of LTB4 production in zymosan-inflamed rabbit knee joint. 6. Topical administration of ICI D2138 to rabbit skin caused a dose-related inhibition of arachidonic acid-induced plasma extravasation with an ID30 of 1.08 nmol per site.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1334748

Design, Synthesis and Biological Evaluation of Novel Pyrimido[4,5-d]pyrimidine CDK2 Inhibitors as Anti-Tumor Agents

PubMed Central

El-Moghazy, Samir M.; Ibrahim, Diaa A.; Abdelgawad, Nagwa M.; Farag, Nahla A. H.; El-Khouly, Ahmad S.

2011-01-01

A series of 2,5,7-trisubstituted pyrimido[4,5-d]pyrimidine cyclin-dependent kinase (CDK2) inhibitors is designed and synthesized. 6-Amino-2-thiouracil is reacted with an aldehyde and thiourea to prepare the pyrimido[4,5-d]-pyrimidines. Alkylation and amination of the latter ones give different amino derivatives. These compounds show potent and selective CDK inhibitory activities and inhibit in vitro cellular proliferation in cultured human tumor cells. PMID:21886895

Regulation of Ca(2+)-dependent protein turnover in skeletal muscle by thyroxine

NASA Technical Reports Server (NTRS)

Zeman, Richard J.; Bernstein, Paul L.; Ludemann, Robert; Etlinger, Joseph D.

1986-01-01

Dantrolene, an agent that inhibits Ca(2+) mobilization, improved protein balance in skeletal muscle, as thyroid status was increased, by altering rates of protein synthesis and degradation. Thyroxine (T4) caused increases in protein degradation that were blocked by leupeptin, a proteinase inhibitor previously shown to inhibit Ca(2+)-dependent nonlysosomal proteolysis in these muscles. In addition, T4 abolished sensitivity to the lysosomotropic agent methylamine and the autophagy inhibitor 3-methyladenine, suggesting that T4 inhibits autophagic/lysosomal proteolysis.

Purification and substrate specificity of polymorphic forms of esterase D from human erythrocytes.

PubMed Central

Scott, E M; Wright, R C

1978-01-01

Esterase D (EsD), purified from human erythrocytes and tested with a variety of substrates, hydrolyzed only triacetin, tributyrin, and certain soluble aryl esters of aliphatic acids. Esters of 4-methylumbelliferone were easily the best substrates. When the three genetically different isozymes were compared, the less common forms, EsD 2 and EsD 2-1, were less stable than EsD 1. With some substrates, the Michaelis constant of the EsD 2 form differed from that of the EsD 1 form. The EsD 2-1 hybrid form was usually, but not invariably, intermediate in properties. The physiologic significance of the genetic variability of this enzyme is unknown. PMID:623100

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

PubMed

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

2012-10-01

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

Synthesis and evaluation of thiophenyl derivatives as inhibitors of alkaline phosphatase.

PubMed

Chang, Lei; Duy, Do Le; Mébarek, Saida; Popowycz, Florence; Pellet-Rostaing, Stéphane; Lemaire, Marc; Buchet, René

2011-04-15

Pathological calcifications induced by deposition of basic phosphate crystals or hydroxyapatite (HA) on soft tissues are a large family of diseases comprising of ankylosing spondylitis (AS), end-stage osteoarthritis (OA) and vascular calcification. High activity of tissue non-specific alkaline phosphatase (TNAP) is a hallmark of pathological calcifications induced by HA deposition. The use of TNAP inhibitor is a possible therapeutic option to address calcific diseases produced by HA deposition on soft tissues. We report the synthesis of a series of thiopheno-imidazo[2,1-b]thiazole derivatives which were evaluated as potential inhibitors of TNAP displaying a large range of IC(50) at pH 10.4 (from 42±13 μM to more than 800 μM). Copyright © 2011. Published by Elsevier Ltd.

Design, Multicomponent Synthesis, and Anticancer Activity of a Focused Histone Deacetylase (HDAC) Inhibitor Library with Peptoid-Based Cap Groups.

PubMed

Krieger, Viktoria; Hamacher, Alexandra; Gertzen, Christoph G W; Senger, Johanna; Zwinderman, Martijn R H; Marek, Martin; Romier, Christophe; Dekker, Frank J; Kurz, Thomas; Jung, Manfred; Gohlke, Holger; Kassack, Matthias U; Hansen, Finn K

2017-07-13

In this work, we report the multicomponent synthesis of a focused histone deacetylase (HDAC) inhibitor library with peptoid-based cap groups and different zinc-binding groups. All synthesized compounds were tested in a cellular HDAC inhibition assay and an MTT assay for cytotoxicity. On the basis of their noteworthy activity in the cellular HDAC assays, four compounds were further screened for their inhibitory activity against recombinant HDAC1-3, HDAC6, and HDAC8. All four compounds showed potent inhibition of HDAC1-3 as well as significant inhibition of HDAC6 with IC 50 values in the submicromolar concentration range. Compound 4j, the most potent HDAC inhibitor in the cellular HDAC assay, revealed remarkable chemosensitizing properties and enhanced the cisplatin sensitivity of the cisplatin-resistant head-neck cancer cell line Cal27CisR by almost 7-fold. Furthermore, 4j almost completely reversed the cisplatin resistance in Cal27CisR. This effect is related to a synergistic induction of apoptosis as seen in the combination of 4j with cisplatin.

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

PubMed

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

2014-05-06

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

Synthesis and antitumour activity of 4-aminoquinazoline derivatives

NASA Astrophysics Data System (ADS)

Lipunova, G. N.; Nosova, E. V.; Charushin, V. N.; Chupakhin, O. N.

2016-07-01

Pieces of data on the synthesis and antitumour activity of 4-aminoquinazolines are summarized and analyzed. Key methods for the synthesis of these compounds are considered, primarily cyclocondensation of carboxylic acid derivatives, as well as the oxidation of quinazolines and the cyclization of disubstituted thioureas. Improvements of synthetic schemes for erlotinib, gefitinib and lapatinib, which are the best-known pharmaceuticals based on compounds of the title class, are also considered. Synthetic strategies and biological activities for new 4-aminoquinazoline derivatives that are EGFR-tyrosine kinase inhibitors, multiactive compounds, and labelled compounds for use as positron emission tomography (PET) imaging agents are discussed. The bibliography includes 263 references.

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

PubMed

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

2010-03-05

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

Thymosin beta 4 up-regulates miR-200a expression and induces differentiation and survival of rat brain progenitor cells.

PubMed

Santra, Manoranjan; Chopp, Michael; Santra, Sutapa; Nallani, Ankita; Vyas, Shivam; Zhang, Zheng Gang; Morris, Daniel C

2016-01-01

Thymosin beta 4 (Tβ4), a secreted 43 amino acid peptide, promotes oligodendrogenesis, and improves neurological outcome in rat models of neurologic injury. We demonstrated that exogenous Tβ4 treatment up-regulated the expression of the miR-200a in vitro in rat brain progenitor cells and in vivo in the peri-infarct area of rats subjected to middle cerebral artery occlusion (MCAO). The up-regulation of miR-200a down-regulated the expression of the following targets in vitro and in vivo models: (i) growth factor receptor-bound protein 2 (Grb2), an adaptor protein involved in epidermal growth factor receptor (EGFR)/Grb2/Ras/MEK/ERK1/c-Jun signaling pathway, which negatively regulates the expression of myelin basic protein (MBP), a marker of mature oligodendrocyte; (ii) ERRFI-1/Mig-6, an endogenous potent kinase inhibitor of EGFR, which resulted in activation/phosphorylation of EGFR; (iii) friend of GATA 2, and phosphatase and tensin homolog deleted in chromosome 10 (PTEN), which are potent inhibitors of the phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathway, and resulted in marked activation of AKT; and (iv) transcription factor, p53, which induces pro-apoptotic genes, and possibly reduced apoptosis of the progenitor cells subjected to oxygen glucose deprivation (OGD). Anti-miR-200a transfection reversed all the effects of Tβ4 treatment in vitro. Thus, Tβ4 up-regulated MBP synthesis, and inhibited OGD-induced apoptosis in a novel miR-200a dependent EGFR signaling pathway. Our findings of miR-200a-mediated protection of progenitor cells may provide a new therapeutic importance for the treatment of neurologic injury. Tβ4-induced micro-RNA-200a (miR-200a) regulates EGFR signaling pathways for MBP synthesis and apoptosis: up-regulation of miR-200a after Tβ4 treatment, increases MBP synthesis after targeting Grb2 and thereby inactivating c-Jun from inhibition of MBP synthesis; and also inhibits OGD-mediated apoptosis after targeting EGFR inhibitor (Mig-6), PI3K inhibitors (FOG2 and Pten) and an inducer (p53) of pro-apoptotic genes, for AKT activation and down-regulation of p53. These findings may contribute the therapeutic benefits for stroke and other neuronal diseases associated with demyelination disorders. © 2015 International Society for Neurochemistry.

Continuous transport of a small fraction of plasma membrane cholesterol to endoplasmic reticulum regulates total cellular cholesterol

PubMed Central

Infante, Rodney Elwood; Radhakrishnan, Arun

2017-01-01

Cells employ regulated transport mechanisms to ensure that their plasma membranes (PMs) are optimally supplied with cholesterol derived from uptake of low-density lipoproteins (LDL) and synthesis. To date, all inhibitors of cholesterol transport block steps in lysosomes, limiting our understanding of post-lysosomal transport steps. Here, we establish the cholesterol-binding domain 4 of anthrolysin O (ALOD4) as a reversible inhibitor of cholesterol transport from PM to endoplasmic reticulum (ER). Using ALOD4, we: (1) deplete ER cholesterol without altering PM or overall cellular cholesterol levels; (2) demonstrate that LDL-derived cholesterol travels from lysosomes first to PM to meet cholesterol needs, and subsequently from PM to regulatory domains of ER to suppress activation of SREBPs, halting cholesterol uptake and synthesis; and (3) determine that continuous PM-to-ER cholesterol transport allows ER to constantly monitor PM cholesterol levels, and respond rapidly to small declines in cellular cholesterol by activating SREBPs, increasing cholesterol uptake and synthesis. DOI: http://dx.doi.org/10.7554/eLife.25466.001 PMID:28414269

Regulation of DNA synthesis and cell division by polyamines in Catharanthus roseus suspension cultures

Treesearch

R. Minocha; S.C. Minocha; A. Komamine; W.C. Shortle

1991-01-01

Various inhibitors of polyamine biosynthesis were used to study the role of polyamines in DNA synthesis and cell division in suspension cultures of Catharanthus roseus (L) G. Don. Arginine decarboxylase (ADC; EC 4.1.1.19) was the major enzyme responsible for putrescine production. DL α-difluoromethylarginine inhibited ADC activity, cellular...

Kinesin spindle protein (KSP) inhibitors. Part 7: Design and synthesis of 3,3-disubstituted dihydropyrazolobenzoxazines as potent inhibitors of the mitotic kinesin KSP.

PubMed

Garbaccio, Robert M; Tasber, Edward S; Neilson, Lou Anne; Coleman, Paul J; Fraley, Mark E; Olson, Christy; Bergman, Jeff; Torrent, Maricel; Buser, Carolyn A; Rickert, Keith; Walsh, Eileen S; Hamilton, Kelly; Lobell, Robert B; Tao, Weikang; South, Vicki J; Diehl, Ronald E; Davide, Joseph P; Yan, Youwei; Kuo, Lawrence C; Li, Chunze; Prueksaritanont, Thomayant; Fernandez-Metzler, Carmen; Mahan, Elizabeth A; Slaughter, Donald E; Salata, Joseph J; Kohl, Nancy E; Huber, Hans E; Hartman, George D

2007-10-15

Observations from two structurally related series of KSP inhibitors led to the proposal and discovery of dihydropyrazolobenzoxazines that possess ideal properties for cancer drug development. The synthesis and characterization of this class of inhibitors along with relevant pharmacokinetic and in vivo data are presented. The synthesis is highlighted by a key [3+2] cycloaddition to form the pyrazolobenzoxazine core followed by diastereospecific installation of a quaternary center.

Synthesis of 5-(ethylsulfonyl)-2-methoxyaniline: An important pharmacological fragment of VEGFR2 and other inhibitors

PubMed Central

Murár, Miroslav; Addová, Gabriela

2013-01-01

Summary Background: 5-(Ethylsulfonyl)-2-methoxyaniline (5) is part of the structure in 131 compounds possessing different biological activities. In most cases, they have antitumor properties (112 compounds). Other compounds are described as cardiovascular agents, ion-channel blockers, nervous-system blockers, anti-inflammatory agents, or antidiabetic, antiosteoporotic and hypolipemic species. Compound 5 is a precursor of different protein-kinase inhibitors or enzyme modulators (EGFR, PDGFR, ckit, CDK 2 and 4, MMPs 2, 3, 9 and 13, etc.). The structure of 5 represents a fragment for several powerful inhibitors of VEGFR2, a key angiogenic receptor. Antiangiogenic inhibitors slow down or stop new blood-vessel formation from pre-existing vasculature. Some antiangiogenic drugs inhibiting the VEGFR2 receptor are successfully used in clinics for the treatment of several types of tumours in synergy with chemotherapy (e.g., Nexavar® from Bayer, Sutent® from Pfizer and Votrient® from GlaxoSmithKline, approved by the FDA in 2005, 2006 and 2009, respectively). The structure of 5 is an important pharmacophoric fragment of potent VEGFR2 inhibitors (e.g., AAZ from PDB complex 1Y6A, enzymatic IC50 = 22 nM). Up to now, 25 VEGFR2 inhibitors possessing a fragment of 5 can be found in the literature. Despite the high significance of 5-(ethylsulfonyl)-2-methoxyaniline (5) its preparation has not yet been described. Results: Here we have developed a convenient synthesis of important polyheterosubstituted aniline 5 starting from commercially available 4-methoxybenzene-1-sulfonyl chloride (1) in four steps and 59% overall yield. The target 5-(ethylsulfonyl)-2-methoxyaniline (5) and its synthetic intermediates 2–4 together with a new compound 5-(ethylsulfonyl)-2-methoxy-1,3-dinitrobenzene (4a) have been precisely physicochemically characterised. PMID:23399884

Design, Synthesis and Biological Evaluation of Oxindole-Based Chalcones as Small-Molecule Inhibitors of Melanogenic Tyrosinase.

PubMed

Suthar, Sharad Kumar; Bansal, Sumit; Narkhede, Niteen; Guleria, Manju; Alex, Angel Treasa; Joseph, Alex

2017-01-01

The enzyme tyrosinase regulates melanogenesis and skin hyperpigmentation by converting L-3,4-dihydroxyphenylalanine (L-DOPA) into dopaquinone, a key step in the melanin biosynthesis. The present work deals with design and synthesis of various oxindole-based chalcones as monophenolase and diphenolase activity inhibitors of tyrosinase. Among the screened compounds, 4-hydroxy-3-methoxybenzylidene moiety bearing chalcone (7) prepared by one pot reaction of oxindole and vanillin displayed the highest activity against tyrosinase with IC 50 s of 63.37 and 59.71 µM in monophenolase and diphenolase activity assays, respectively. In molecular docking studies, chalcone 7 also showed the highest binding affinity towards the enzyme tyrosinase while exhibiting the lowest estimated free energy of binding, among all the ligands docked.

Physiological effects in bovine lymphocytes of inhibiting polyamine synthesis with ethylglyoxal bis(guanylhydrazone).

PubMed

Igarashi, K; Morris, D R

1984-11-01

Previous results have suggested that ethylglyoxal bis(guanylhydrazone) is a more specific inhibitor of polyamine biosynthesis than the widely used methylglyoxal bis(guanylhydrazone). The physiological effects on mitogenically activated lymphocytes of polyamine depletion with ethylglyoxal bis(guanylhydrazone) were examined. In the presence of ethylglyoxal bis(guanylhydrazone) and the ornithine decarboxylase inhibitor alpha-difluoromethylornithine, the cellular contents of putrescine, spermidine, and spermine were decreased by 75 to 90, 65 to 80, and 40 to 60%, respectively, compared with control cultures. Inhibition of DNA synthesis in these polyamine-deficient cells was always greater than that of protein synthesis. Upon addition of spermidine to the deficient cells, the cellular spermidine content was restored within 4 hr, but the complete recovery of macromolecular synthesis took 10 to 20 hr. Thymidine kinase and DNA polymerase alpha activities in polyamine-deficient cells were lower than those in normal cells, whereas RNA polymerase II and leucyl transfer RNA synthase activities were nearly equal to those in normal cells. These results and studies with 2-dimensional gel electrophoresis raise the possibility that polyamines may regulate the synthesis of specific proteins. Decreased synthesis of replication proteins in polyamine-deficient cells may be one reason for the reduced synthesis of DNA.

Biological Synthesis of a Protein Analogue of Acetylcholinesterase: Monoclonal Anti-Idiotype Antibody Analogue of the Esteratic Site.

DTIC Science & Technology

1986-07-10

site- directed inhibitor DFP, the reversible site-directed inhibitors neostigmine, carbachol , edrophonium, and BW284c51; and the allosteric site...Esteratic 10-6 10 -7 - I0-2 Neostigmine Esteratic 10- 7 10- 6 - 10 5 Anionic PI Carbachol Esteratic 10- 4 10 3 10-1 Anionic PI Edrophonium Anionic 10

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

PubMed

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

2010-02-01

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

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

PubMed

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

2005-03-15

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

Synthesis and Characterization of Compounds Related to Lisinopril

PubMed Central

Raghava Reddy, Ambati V.; Garaga, Srinivas; Takshinamoorthy, Chandiran; Naidu, Andra; Dandala, Ramesh

2016-01-01

Lisinopril is a drug of the angiotensin-converting enzyme (ACE) inhibitor class that is primarily used in the treatment of hypertension. During the scale-up of the lisinopril process, one unknown impurity was observed and is identified. The present work describes the origin, synthesis, characterization, and control of this impurity. This paper also describes the synthesis and characterization of three other impurities listed in the European Pharmacopoeia 8.4 (Impurity C, D, and F). PMID:27222603

Acyl guanidine inhibitors of β-secretase (BACE-1): optimization of a micromolar hit to a nanomolar lead via iterative solid- and solution-phase library synthesis.

PubMed

Gerritz, Samuel W; Zhai, Weixu; Shi, Shuhao; Zhu, Shirong; Toyn, Jeremy H; Meredith, Jere E; Iben, Lawrence G; Burton, Catherine R; Albright, Charles F; Good, Andrew C; Tebben, Andrew J; Muckelbauer, Jodi K; Camac, Daniel M; Metzler, William; Cook, Lynda S; Padmanabha, Ramesh; Lentz, Kimberley A; Sofia, Michael J; Poss, Michael A; Macor, John E; Thompson, Lorin A

2012-11-08

This report describes the discovery and optimization of a BACE-1 inhibitor series containing an unusual acyl guanidine chemotype that was originally synthesized as part of a 6041-membered solid-phase library. The synthesis of multiple follow-up solid- and solution-phase libraries facilitated the optimization of the original micromolar hit into a single-digit nanomolar BACE-1 inhibitor in both radioligand binding and cell-based functional assay formats. The X-ray structure of representative inhibitors bound to BACE-1 revealed a number of key ligand:protein interactions, including a hydrogen bond between the side chain amide of flap residue Gln73 and the acyl guanidine carbonyl group, and a cation-π interaction between Arg235 and the isothiazole 4-methoxyphenyl substituent. Following subcutaneous administration in rats, an acyl guanidine inhibitor with single-digit nanomolar activity in cells afforded good plasma exposures and a dose-dependent reduction in plasma Aβ levels, but poor brain exposure was observed (likely due to Pgp-mediated efflux), and significant reductions in brain Aβ levels were not obtained.

Design, synthesis, and biological activity of second-generation synthetic oleanane triterpenoids.

PubMed

Fu, Liangfeng; Lin, Qi-Xian; Onyango, Evans O; Liby, Karen T; Sporn, Michael B; Gribble, Gordon W

2017-07-19

We report the synthesis and biological activity of C-24 demethyl CDDO-Me 2 and the C-28 amide derivatives 3 and 4, which are analogues of the anti-inflammatory synthetic triterpenoid bardoxolone methyl (CDDO-Me) 1. Demethylation of the C-24 methyl group was accomplished via "abnormal Beckmann" rearrangement and subsequent ring A reformation. Amides 3 and 4 were found to be potent inhibitors of the production of the inflammatory mediator NO in vitro.

2-(4-(Biphenyl-4-ylamino)-6-chloropyrimidin-2-ylthio)octanoic acid (HZ52) – a novel type of 5-lipoxygenase inhibitor with favourable molecular pharmacology and efficacy in vivo

PubMed Central

Greiner, C; Hörnig, C; Rossi, A; Pergola, C; Zettl, H; Schubert-Zsilavecz, M; Steinhilber, D; Sautebin, L; Werz, O

2011-01-01

BACKGROUND AND PURPOSE 5-Lipoxygenase (5-LO) is the key enzyme in the biosynthesis of pro-inflammatory leukotrienes (LTs) representing a potential target for pharmacological intervention with inflammation and allergic disorders. Although many LT synthesis inhibitors are effective in simple in vitro test systems, they frequently fail in vivo due to lack of efficacy. Here, we attempted to assess the pharmacological potential of the previously identified 5-LO inhibitor 2-(4-(biphenyl-4-ylamino)-6-chloropyrimidin-2-ylthio)octanoic acid (HZ52). EXPERIMENTAL APPROACH We evaluated the efficacy of HZ52 in vivo using carrageenan-induced pleurisy in rats and platelet-activating factor (PAF)-induced lethal shock in mice. We also characterized 5-LO inhibition by HZ52 at the cellular and molecular level in comparison with other types of 5-LO inhibitor, that is, BWA4C, ZM230487 and hyperforin. KEY RESULTS HZ52, 1.5 mg·kg−1 i.p., prevented carrageenan-induced pleurisy accompanied by reduced LTB4 levels and protected mice (10 mg·kg−1, i.p.) against PAF-induced shock. Detailed analysis in cell-based and cell-free assays revealed that inhibition of 5-LO by HZ52 (i) does not depend on radical scavenging properties and is reversible; (ii) is not impaired by an increased peroxide tone or by elevated substrate concentrations; and (iii) is little affected by the cell stimulus or by phospholipids, glycerides, membranes or Ca2+. CONCLUSIONS AND IMPLICATIONS HZ52 is a promising new type of 5-LO inhibitor with efficacy in vivo and with a favourable pharmacological profile. It possesses a unique 5-LO inhibitory mechanism different from classical 5-LO inhibitors and seemingly lacks the typical disadvantages of former classes of LT synthesis blockers. PMID:21506958

Improved synthesis of (3E,6Z,9Z)-1,3,6,9-nonadecatetraene, attraction inhibitor of bruce spanworm, Operophtera bruceata, to pheromone traps for monitoring winter moth, Operophtera brumata.

PubMed

Khrimian, Ashot; Lance, David R; Mastro, Victor C; Elkinton, Joseph S

2010-02-10

The winter moth, Operophtera brumata (Lepidoptera: Geometridae), is an early-season defoliator that attacks a wide variety of hardwoods and, in some cases, conifers. The insect is native to Europe but has become established in at least three areas of North America including southeastern New England. The female-produced sex attractant pheromone of the winter moth was identified as (3Z,6Z,9Z)-1,3,6,9-nonadecatetraene (1), which also attracts a native congener, the Bruce spanworm, Operophtera bruceata . Dissection, or (for certainty) DNA molecular testing, is required to differentiate between males of the two species. Thus, a trapping method that is selective for winter moth would be desirable. A geometric isomer of the pheromone, (3E,6Z,9Z)-1,3,6,9-nonadecatetraene (2), can reportedly inhibit attraction of Bruce spanworm to traps without affecting winter moth catch, but use of the pheromone and inhibitor together has not been optimized, nor has the synthesis of the inhibitor. This paper presents two new syntheses of the inhibitor (3E,6Z,9Z)-1,3,6,9-nonadecatetraene based on the intermediate (3Z,6Z)-3,6-hexadecadien-1-ol (4), which has also been utilized in the synthesis of the pheromone. The syntheses combine traditional acetylenic chemistry and Wittig olefination reactions. In one approach, 2 was synthesized in 80% purity (20% being pheromone 1), and in the second, tetraene 2 of 96% purity (and free of 1) was produced in 25% overall yield from dienol 4. The last method benefitted from a refined TEMPO-mediated PhI(OAc)(2) oxidation of 4 and a two-carbon homologation of the corresponding aldehyde 7.

Synthesis and biological evaluation of 3,6-diamino-1H-pyrazolo[3,4-b]pyridine derivatives as protein kinase inhibitors.

PubMed

Chioua, Mourad; Samadi, Abdelouahid; Soriano, Elena; Lozach, Olivier; Meijer, Laurent; Marco-Contelles, José

2009-08-15

The synthesis and biological evaluation of a number of differently substituted 3,6-diamino-1H-pyrazolo[3,4-b]pyridine derivatives are reported. From the inhibition results on a selection of disease-relevant protein kinases [IC(50) (microM) DYRK1A=11; CDK5=0.41; GSK-3=1.5] we have observed that 3,6-diamino-4-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile (4) constitutes a potential new and simple lead compound in the search of drugs for the treatment of Alzheimer's disease.

Enantio- and stereoselective route to the phoslactomycin family of antibiotics: formal synthesis of (+)-fostriecin and (+)-phoslactomycin B.

PubMed

Sarkar, Shaheen M; Wanzala, Everlyne N; Shibahara, Setsuya; Takahashi, Keisuke; Ishihara, Jun; Hatakeyama, Susumi

2009-10-21

A general methodology applicable for the synthesis of the phoslactomycin family of antibiotics, potent and selective protein phosphatase inhibitors, has been developed starting from a beta-isocupreidine-catalyzed asymmetric Baylis-Hillman reaction of 3-(4-methoxybenzyloxy)propanal with hexafluoroisopropyl acrylate, and thereby formal syntheses of (+)-fostriecin and (+)-phoslactomycin B have been accomplished.

Synthesis of three bromophenols from red algae as PTP1B inhibitors

NASA Astrophysics Data System (ADS)

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

2011-01-01

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

Synthesis and structure-activity relationship study of pyrazolo[3,4-d]pyrimidines as tyrosine kinase RET inhibitors.

PubMed

Wang, Chengyan; Liu, Hongchun; Song, Zilan; Ji, Yinchun; Xing, Li; Peng, Xia; Wang, Xisheng; Ai, Jing; Geng, Meiyu; Zhang, Ao

2017-06-01

Three series of pyrazolo[3,4-d]pyrimidine derivatives were synthesized and evaluated as RET kinase inhibitors. Compounds 23a and 23c were identified to show significant activity both in the biochemical and the BaF3/CCDC6-RET cell assays. Compound 23c was found to significantly inhibit RET phosphorylation and down-stream signaling in BaF3/CCDC6-RET cells, confirming its potent cellular RET-targeting profile. Different from other RET inhibitors with equal potency against KDR that associated with severe toxicity, 23c did not show significant KDR-inhibition even at the concentration of 1μM. These results demonstrated that 23c is a potent and selective RET inhibitor. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Cytotoxicity of chimera peptides incorporating sequences of cyclin kinases inhibitors].

PubMed

Kharchenko, V P; Kulinich, V G; Lunin, V G; Filiasova, E I; Shishkin, A M; Sergeenko, O V; Riazanova, E M; Voronina, O L; Bozhenko, V K

2007-01-01

The study is concerned with proapoptotic properties of chimera peptides which incorporate sequences of inhibitors of cyclin kinases p161NK4a and p21CIP/WAF1 as well as internalized sequences (Antp and tat). Sequences of the p16 type appeared to be more cytotoxic than the p21 one. Cytotoxic effect proved dependent on orientation with respect to the C or N terminal point of a polypeptide chain rather than on chimera sequence extent. Although p16 endogenous synthesis did not influence chimera peptide levels, apoptosis did not take place in certain cellular lines. Due to the rather unsophisticated nature of such synthesis, it might be used in designing individually-tailored chemotherapeutic drugs.

Synthesis and biological evaluation of di-aryl urea derivatives as c-Kit inhibitors.

PubMed

Ravez, Séverine; Arsenlis, Stéphane; Barczyk, Amélie; Dupont, Anthony; Frédérick, Raphaël; Hesse, Stéphanie; Kirsch, Gilbert; Depreux, Patrick; Goossens, Laurence

2015-11-15

Inhibition of receptor tyrosine kinases (RTKs) continued to be a successful approach for the treatment of many types of human cancers and many potent small molecules kinase inhibitors have been discovered the last decade. In the present study, we describe the synthesis of thienopyrimidine derivatives and their pharmacological evaluation against nine kinases (EGFR, PDGFR-ß, c-Kit, c-Met, Src, Raf, VEGFR-1, -2 and -3). Most of the synthesized compounds showed from moderate to potent activities against c-Kit with IC50 values in the nanomolar range. Among them, 4-anilino(urea)thienopyrimidine analogs showed selectivity and potent c-Kit inhibition with IC50 values less than 6 nM. Docking simulation was performed for the most promising compound 9 into the c-Kit active site to determine the potential binding mode. This study reveal that the 4-anilino(urea)thienopyrimidine is an interesting scaffold to design novel potent and selective c-Kit inhibitors which may make promising candidates for cancers where c-Kit receptors are overexpressed. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed

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

2017-10-01

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

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

New 5-benzylidenethiazolidin-4-one inhibitors of bacterial MurD ligase: design, synthesis, crystal structures, and biological evaluation.

PubMed

Zidar, Nace; Tomašić, Tihomir; Šink, Roman; Kovač, Andreja; Patin, Delphine; Blanot, Didier; Contreras-Martel, Carlos; Dessen, Andréa; Premru, Manica Müller; Zega, Anamarija; Gobec, Stanislav; Mašič, Lucija Peterlin; Kikelj, Danijel

2011-11-01

Mur ligases (MurC-MurF), a group of bacterial enzymes that catalyze four consecutive steps in the formation of cytoplasmic peptidoglycan precursor, are becoming increasingly adopted as targets in antibacterial drug design. Based on the crystal structure of MurD cocrystallized with thiazolidine-2,4-dione inhibitor I, we have designed, synthesized, and evaluated a series of improved glutamic acid containing 5-benzylidenerhodanine and 5-benzylidenethiazolidine-2,4-dione inhibitors of MurD with IC(50) values up to 28 μM. Inhibitor 37, with an IC(50) of 34 μM, displays a weak antibacterial activity against S. aureus ATCC 29213 and E. faecalis ATCC 29212 with minimal inhibitory concentrations of 128 μg/mL. High-resolution crystal structures of MurD in complex with two new inhibitors (compounds 23 and 51) reveal details of their binding modes within the active site and provide valuable information for further structure-based optimization. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Suppression of the formation of polyamines and macromolecules by dl-α-difluoromethylornithine and methylglyoxal bis(guanylhydrazone) in phytohaemagglutinin-activated human lymphocytes

PubMed Central

Jänne, Juhani; Hovi, Tapani; Hölttä, Erkki

1979-01-01

1. The activation of human peripheral blood lymphocytes by phytohaemagglutinin in vitro was accompanied by striking increases in the concentrations of the natural polyamines putrescine, spermidine and spermine. 2. The enhanced accumulation of polyamines could be almost totally abolished by dl-α-difluoromethylornithine, a newly discovered irreversible inhibitor of l-ornithine decarboxylase (EC 4.1.1.17), or by methylglyoxal bis(guanylhydrazone) {1,1′-[(methylethanediylidene)dinitrilo]diguanidine}, an inhibitor of S-adenosyl-l-methionine decarboxylase (EC 4.1.1.50). The inhibition of polyamine accumulation was associated with a marked suppression of DNA synthesis, which was partially or totally reversed by low concentrations of exogenous putrescine, spermidine, spermine and cadaverine and by higher concentrations of 1,3-diaminopropane. 3. In contrast with some earlier studies, we found that methylglyoxal bis(guanylhydrazone), at concentrations that were sufficient to prevent polyamine accumulation, also caused a clear inhibition of protein synthesis in the activated lymphocytes. Similar results were obtained with difluoromethylornithine. The decrease in protein synthesis caused by both compounds preceded the impairment of DNA synthesis. The inhibition of protein synthesis by difluoromethylornithine was fully reversed by exogenous putrescine, spermidine and spermine, and that caused by methylglyoxal bis(guanylhydrazone) by spermidine and spermine. In further support of the idea that the inhibition of protein synthesis by these compounds was related to the polyamine depletion, we found that difluoromethylornithine caused a dose-dependent decrease in the incorporation of [14C]leucine into lymphocyte proteins which closely correlated with the decreased concentrations of cellular spermidine. 4. Difluoromethylornithine and methylglyoxal bis(guanylhydrazone) also elicited a variable depression in the incorporation of [3H]uridine and [14C]adenine into total RNA. The apparent turnover of lymphocyte RNA remained essentially unchanged in spite of severe polyamine depletion brought about by difluoromethylornithine. 5. The present results, as well as confirming the anti-proliferative action of the inhibitors of polyamine biosynthesis, suggest that polyamine depletion may interfere with reactions at different levels of gene expression. PMID:435270

Suppression of the formation of polyamines and macromolecules by DL-alpha-difluoromethylornithine and methylglyoxal bis(guanylhydrazone) in phytohaemagglutinin-activated human lymphocytes.

PubMed

Hölttä, E; Jänne, J; Hovi, T

1979-01-15

1. The activation of human peripheral blood lymphocytes by phytohaemagglutinin in vitro was accompanied by striking increases in the concentrations of the natural polyamines putrescine, spermidine and spermine. 2. The enhanced accumulation of polyamines could be almost totally abolished by dl-alpha-difluoromethylornithine, a newly discovered irreversible inhibitor of l-ornithine decarboxylase (EC 4.1.1.17), or by methylglyoxal bis(guanylhydrazone) {1,1'-[(methylethanediylidene)dinitrilo]diguanidine}, an inhibitor of S-adenosyl-l-methionine decarboxylase (EC 4.1.1.50). The inhibition of polyamine accumulation was associated with a marked suppression of DNA synthesis, which was partially or totally reversed by low concentrations of exogenous putrescine, spermidine, spermine and cadaverine and by higher concentrations of 1,3-diaminopropane. 3. In contrast with some earlier studies, we found that methylglyoxal bis(guanylhydrazone), at concentrations that were sufficient to prevent polyamine accumulation, also caused a clear inhibition of protein synthesis in the activated lymphocytes. Similar results were obtained with difluoromethylornithine. The decrease in protein synthesis caused by both compounds preceded the impairment of DNA synthesis. The inhibition of protein synthesis by difluoromethylornithine was fully reversed by exogenous putrescine, spermidine and spermine, and that caused by methylglyoxal bis(guanylhydrazone) by spermidine and spermine. In further support of the idea that the inhibition of protein synthesis by these compounds was related to the polyamine depletion, we found that difluoromethylornithine caused a dose-dependent decrease in the incorporation of [(14)C]leucine into lymphocyte proteins which closely correlated with the decreased concentrations of cellular spermidine. 4. Difluoromethylornithine and methylglyoxal bis(guanylhydrazone) also elicited a variable depression in the incorporation of [(3)H]uridine and [(14)C]adenine into total RNA. The apparent turnover of lymphocyte RNA remained essentially unchanged in spite of severe polyamine depletion brought about by difluoromethylornithine. 5. The present results, as well as confirming the anti-proliferative action of the inhibitors of polyamine biosynthesis, suggest that polyamine depletion may interfere with reactions at different levels of gene expression.

Design of novel HIV-1 protease inhibitors incorporating isophthalamide-derived P2-P3 ligands: Synthesis, biological evaluation and X-ray structural studies of inhibitor-HIV-1 protease complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Arun K.; Brindisi, Margherita; Nyalapatla, Prasanth R.

Based upon molecular insights from the X-ray structures of inhibitor-bound HIV-1 protease complexes, we have designed a series of isophthalamide-derived inhibitors incorporating substituted pyrrolidines, piperidines and thiazolidines as P2-P3 ligands for specific interactions in the S2-S3 extended site. Compound 4b has shown an enzyme Ki of 0.025 nM and antiviral IC50 of 69 nM. An X-ray crystal structure of inhibitor 4b-HIV-1 protease complex was determined at 1.33 Å resolution. We have also determined X-ray structure of 3b-bound HIV-1 protease at 1.27 Å resolution. These structures revealed important molecular insight into the inhibitor–HIV-1 protease interactions in the active site.

IL-4 inhibits the synthesis of IFN-gamma and induces the synthesis of IgE in human mixed lymphocyte cultures.

PubMed

Vercelli, D; Jabara, H H; Lauener, R P; Geha, R S

1990-01-15

The T cell-derived lymphokine IL-4 is essential for the induction of IgE synthesis by human lymphocytes. The IgE-inducing effect of IL-4 is antagonized by IFN-gamma. The secretion of IFN-gamma is vigorously triggered in MLC. Thus, IL-4-stimulated MLC represent a suitable model to characterize the functional antagonism between IL-4 and IFN-gamma. In this report, we show that rIL-4 consistently induced IgE synthesis when added to human primary MLC. IL-4-dependent IgE production required cognate T/B cell recognition, because it was inhibited by antibodies to CD3 and MHC class II (HlA-DR) Ag. A neutralizing anti-IFN-gamma mAb dramatically enhanced IL-4-dependent IgE synthesis by MLC, indicating that endogenous IFN-gamma is a major inhibitor of IgE production. More importantly, addition of rIL-4 markedly inhibited the release of IFN-gamma in supernatants of MLC and Con A-activated PBMC. The decrease in IFN-gamma protein was accompanied by a decreased expression of IFN-gamma mRNA transcripts. The downregulation of IFN-gamma by IL-4 is likely to play an important role in the IL-4-dependent induction of IgE synthesis.

Synthesis, computational studies and enzyme inhibitory kinetics of substituted methyl[2-(4-dimethylamino-benzylidene)-hydrazono)-4-oxo-thiazolidin-5-ylidene]acetates as mushroom tyrosinase inhibitors.

PubMed

Channar, Pervaiz Ali; Saeed, Aamer; Larik, Fayaz Ali; Rafiq, Muhammad; Ashraf, Zaman; Jabeen, Farukh; Fattah, Tanzeela Abdul

2017-11-01

The present article describes the synthesis and enzyme inhibitory kinetics of methyl[2-(arylmethylene-hydrazono)-4-oxo-thiazolidin-5-ylidene]acetates 5a-j as mushroom tyrosinase inhibitors. The title compounds were synthesized via cyclocondensation of thiosemicarbazones 3a-j with dimethyl but-2-ynedioate (DMAD) 4 in good yields under solvent-free conditions. The synthesized compounds were evaluated for their potential to inhibit the activity of mushroom tyrosinase. It was unveiled that compounds 5i showed excellent enzyme inhibitory activity with IC 50 3.17µM while IC 50 of standard kojic acid is 15.91µM. The presence of heterocyclic pyridine ring in compound 5i play important role in enzyme inhibitory activity as rest of the functional groups are common in all synthesized compounds. The enzyme inhibitory kinetics of the most potent derivative 5i determined by Lineweaver-Burk plots and Dixon plots showed that it is non-competitive inhibitor with Ki value 1.5µM. It was further investigated that the wet lab results are in good agreement with the computational results. The molecular docking of the synthesized compounds was performed against tyrosinase protein (PDBID 2Y9X) to delineate ligand-protein interactions at molecular level. The docking results showed that the major interacting residues are His244, His85, His263, Val 283, His 296, Asn260, Val248, His260, His261 and Phe264 which are located in active binding site of the protein. The molecular modeling demonstrates that the oxygen atom of the compound 5i coordinated with the key residues in the active site of mushroom tyrosinase contribute significantly against inhibitory ability and diminishing the human melanin synthesis. These results evident that compound 5i is a lead structure in developing most potent mushroom tyrosinase inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Oral Treatment of Rodents with Insecticides for Control of Sand Flies (Diptera: Psychodidae) and the Fluorescent Tracer Technique (FTT) as a Tool to Evaluate Potential Sand Fly Control Methods

DTIC Science & Technology

2011-03-01

chitin synthesis inhibitors diflubenzuron and novaluron evaluated in these studies were...effective against sand fly larvae and palatable to hamsters. In contrast to the chitin synthesis inhibitors and juvenile hormone analogs...concentrations (mg/kg) Effects Chitin synthesis inhibitor Diflubenzuron 8.97, 89.7, 897 Mortality at larva-to-pupa molt Novaluron 9.88, 98.8,

4-substituted cyclohexyl sulfones as potent, orally active gamma-secretase inhibitors.

PubMed

Churcher, Ian; Beher, Dirk; Best, Jonathan D; Castro, José L; Clarke, Earl E; Gentry, Amy; Harrison, Timothy; Hitzel, Laure; Kay, Euan; Kerrad, Sonia; Lewis, Huw D; Morentin-Gutierrez, Pablo; Mortishire-Smith, Russell; Oakley, Paul J; Reilly, Michael; Shaw, Duncan E; Shearman, Mark S; Teall, Martin R; Williams, Susie; Wrigley, Jonathan D J

2006-01-15

The protease gamma-secretase plays a pivotal role in the synthesis of pathogenic amyloid-beta in Alzheimer's disease (AD). Here, we report a further extension to a series of cyclohexyl sulfone-based gamma-secretase inhibitors which has allowed the preparation of highly potent compounds which also demonstrate robust Abeta(40) lowering in vivo (e.g., compound 32, MED 1mg/kg p.o. in APP-YAC mice).

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

PubMed

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

2018-03-10

3-(β-d-Glucopyranosyl)-5-substituted-1,2,4-triazoles have been revealed as an effective scaffold for the development of potent glycogen phosphorylase (GP) inhibitors but with the potency very sensitive to the nature of the alkyl/aryl 5-substituent (Kun et al., Eur. J. Med. Chem. 2014, 76, 567). For a training set of these ligands, quantum mechanics-polarized ligand docking (QM-PLD) demonstrated good potential to identify larger differences in potencies (predictive index PI = 0.82) and potent inhibitors with K i 's < 10 μM (AU-ROC = 0.86). Accordingly, in silico screening of 2335 new analogues exploiting the ZINC docking database was performed and nine predicted candidates selected for synthesis. The compounds were prepared in O-perbenzoylated forms by either ring transformation of 5-β-d-glucopyranosyl tetrazole by N-benzyl-arenecarboximidoyl chlorides, ring closure of C-(β-d-glucopyranosyl)formamidrazone with aroyl chlorides, or that of N-(β-d-glucopyranosylcarbonyl)arenethiocarboxamides by hydrazine, followed by deprotections. Kinetics experiments against rabbit muscle GPb (rmGPb) and human liver GPa (hlGPa) revealed five compounds as potent low μM inhibitors with three of these on the submicromolar range for rmGPa. X-ray crystallographic analysis sourced the potency to a combination of favorable interactions from the 1,2,4-triazole and suitable aryl substituents in the GP catalytic site. The compounds also revealed promising calculated pharmacokinetic profiles. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

ApoB-100 secretion by HepG2 cells is regulated by the rate of triglyceride biosynthesis but not by intracellular lipid pools.

PubMed

Benoist, F; Grand-Perret, T

1996-10-01

Triglycerides (TGs), cholesteryl esters (CEs), cholesterol, and phosphatidylcholine have been independently proposed as playing regulatory roles in apoB-100 secretion; the results depended on the cellular model used. In this study, we reinvestigate the role of lipids in apoB-100 production in HepG2 cells and in particular, we clarify the respective roles of intracellular mass and the biosynthesis of lipids in the regulation of apoB-100 production. In a first set of experiments, the pool size of cholesterol, CEs, and TGs was modulated by a 3-day treatment with either lipid precursors or inhibitors of enzymes involved in lipid synthesis. We used simvastatin (a hydroxymethylglutaryl coenzyme A reductase inhibitor), 58-035 (an acyl coenzyme A cholesterol acyltransferase inhibitor), 5-tetradecyloxy-2-furancarboxylic acid (TOFA, an inhibitor of fatty acid synthesis), and oleic acid. The secretion rate of apoB-100 was not affected by the large modulation of lipid mass induced by these various pre-treatments. In a second set of experiments, the same lipid modulators were added during a 4-hour labeling period. Simvastatin and 58-035 inhibited cholesterol and CE synthesis without affecting apoB-100 secretion. By contrast, treatment of HepG2 cells with TOFA resulted in the inhibition of TG synthesis and apoB-100 secretion. This effect was highly specific for apoB-100 and was reversed by adding oleic acid, which stimulated both TG synthesis and apoB-100 secretion. Moreover, a combination of oleic acid and 58-035 inhibited CE biosynthesis and increased both TG synthesis and apoB-100 secretion. These results show that in HepG2 cells TG biosynthesis regulates apoB-100 secretion, whereas the rate of cholesterol or CE biosynthesis has no effect.

Design, Synthesis, Biological Evaluation, and X-ray Studies of HIV-1 Protease Inhibitors with Modified P2′ Ligands of Darunavir

PubMed Central

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

2018-01-01

The structure-based design, synthesis, and biological evaluation of a series of nonpeptidic HIV-1 protease inhibitors with rationally designed P2′ ligands are described. The inhibitors are designed to enhance backbone binding interactions, particularly at the S2′ subsite. Synthesis of inhibitors was carried out efficiently. The stereochemistry of alcohol functionalities of the P2′ ligands was set by asymmetric reduction of the corresponding ketone using (R,R)- or (S,S)-Noyori catalysts. A number of inhibitors displayed very potent enzyme inhibitory and antiviral activity. Inhibitors 3g and 3h showed enzyme Ki values of 27.9 and 49.7 pM and antiviral activity of 6.2 and 3.9 nM, respectively. These inhibitors also remained quite potent against darunavir-resistant HIV-1 variants. An X-ray structure of inhibitor 3g in complex with HIV-1 protease revealed key interactions in the S2′ subsite. PMID:29110408

Design, synthesis, and biological evaluation of 3,4-dihydroquinolin-2(1H)-one and 1,2,3,4-tetrahydroquinoline-based selective human neuronal nitric oxide synthase (nNOS) inhibitors.

PubMed

Ramnauth, Jailall; Speed, Joanne; Maddaford, Shawn P; Dove, Peter; Annedi, Subhash C; Renton, Paul; Rakhit, Suman; Andrews, John; Silverman, Sarah; Mladenova, Gabriela; Zinghini, Salvatore; Nair, Sheela; Catalano, Concettina; Lee, David K H; De Felice, Milena; Porreca, Frank

2011-08-11

Neuronal nitric oxide synthase (nNOS) inhibitors are effective in preclinical models of many neurological disorders. In this study, two related series of compounds, 3,4-dihydroquinolin-2(1H)-one and 1,2,3,4-tetrahydroquinoline, containing a 6-substituted thiophene amidine group were synthesized and evaluated as inhibitors of human nitric oxide synthase (NOS). A structure-activity relationship (SAR) study led to the identification of a number of potent and selective nNOS inhibitors. Furthermore, a few representative compounds were shown to possess druglike properties, features that are often difficult to achieve when designing nNOS inhibitors. Compound (S)-35, with excellent potency and selectivity for nNOS, was shown to fully reverse thermal hyperalgesia when given to rats at a dose of 30 mg/kg intraperitonieally (ip) in the L5/L6 spinal nerve ligation model of neuropathic pain (Chung model). In addition, this compound reduced tactile hyperesthesia (allodynia) after oral administration (30 mg/kg) in a rat model of dural inflammation relevant to migraine pain.

Discovery, synthesis, and pharmacological evaluation of spiropiperidine hydroxamic acid based derivatives as structurally novel histone deacetylase (HDAC) inhibitors.

PubMed

Varasi, Mario; Thaler, Florian; Abate, Agnese; Bigogno, Chiara; Boggio, Roberto; Carenzi, Giacomo; Cataudella, Tiziana; Dal Zuffo, Roberto; Fulco, Maria Carmela; Rozio, Marco Giulio; Mai, Antonello; Dondio, Giulio; Minucci, Saverio; Mercurio, Ciro

2011-04-28

New spiro[chromane-2,4'-piperidine] and spiro[benzofuran-2,4'-piperidine] hydroxamic acid derivatives as HDAC inhibitors have been identified by combining privileged structures with a hydroxamic acid moiety as zinc binding group. The compounds were evaluated for their ability to inhibit nuclear extract HDACs and for their in vitro antiproliferative activity on different tumor cell lines. This work resulted in the discovery of spirocycle 30d that shows good oral bioavailability and tumor growth inhibition in an HCT-116 murine xenograft model.

Inhibition of tyrosinase by 4H-chromene analogs: Synthesis, kinetic studies, and computational analysis.

PubMed

Brasil, Edikarlos M; Canavieira, Luciana M; Cardoso, Érica T C; Silva, Edilene O; Lameira, Jerônimo; Nascimento, José L M; Eifler-Lima, Vera L; Macchi, Barbarella M; Sriram, Dharmarajan; Bernhardt, Paul V; Silva, José Rogério Araújo; Williams, Craig M; Alves, Cláudio N

2017-11-01

Inhibition of mushroom tyrosinase was observed with synthetic dihydropyrano[3,2-b]chromenediones. Among them, DHPC04 displayed the most potent tyrosinase inhibitory activity with a K i value of 4 μm, comparable to the reference standard inhibitor kojic acid. A kinetic study suggested that these synthetic heterocyclic compounds behave as competitive inhibitors for the L-DOPA binding site of the enzyme. Furthermore, molecular modeling provided important insight into the mechanism of binding interactions with the tyrosinase copper active site. © 2017 John Wiley & Sons A/S.

Synthesis, biological evaluation, and 3D QSAR study of 2-methyl-4-oxo-3-oxetanylcarbamic acid esters as N-acylethanolamine acid amidase (NAAA) inhibitors.

PubMed

Ponzano, Stefano; Berteotti, Anna; Petracca, Rita; Vitale, Romina; Mengatto, Luisa; Bandiera, Tiziano; Cavalli, Andrea; Piomelli, Daniele; Bertozzi, Fabio; Bottegoni, Giovanni

2014-12-11

N-(2-Oxo-3-oxetanyl)carbamic acid esters have recently been reported to be noncompetitive inhibitors of the N-acylethanolamine acid amidase (NAAA) potentially useful for the treatment of pain and inflammation. In the present study, we further explored the structure-activity relationships of the carbamic acid ester side chain of 2-methyl-4-oxo-3-oxetanylcarbamic acid ester derivatives. Additional favorable features in the design of potent NAAA inhibitors have been found together with the identification of a single digit nanomolar inhibitor. In addition, we devised a 3D QSAR using the atomic property field method. The model turned out to be able to account for the structural variability and was prospectively validated by designing, synthesizing, and testing novel inhibitors. The fairly good agreement between predictions and experimental potency values points to this 3D QSAR model as the first example of quantitative structure-activity relationships in the field of NAAA inhibitors.

Predictive Modeling of a Mixture of Thyroid Hormone Disrupting Chemicals that Affect Production and Clearance of Thyroxine

EPA Science Inventory

Thyroid hormone (TH) disrupting compounds interfere with both thyroidal and extrathyroidal mechanisms to decrease circulating thyroxine (T4). This research tested the hypothesis that serum T4 concentrations of rodents exposed to a mixture of both TH synthesis inhibitors (pesticid...

The identification of 2-(1H-indazol-4-yl)-6-(4-methanesulfonyl-piperazin-1-ylmethyl)-4-morpholin-4-yl-thieno[3,2-d]pyrimidine (GDC-0941) as a potent, selective, orally bioavailable inhibitor of class I PI3 kinase for the treatment of cancer .

PubMed

Folkes, Adrian J; Ahmadi, Khatereh; Alderton, Wendy K; Alix, Sonia; Baker, Stewart J; Box, Gary; Chuckowree, Irina S; Clarke, Paul A; Depledge, Paul; Eccles, Suzanne A; Friedman, Lori S; Hayes, Angela; Hancox, Timothy C; Kugendradas, Arumugam; Lensun, Letitia; Moore, Pauline; Olivero, Alan G; Pang, Jodie; Patel, Sonal; Pergl-Wilson, Giles H; Raynaud, Florence I; Robson, Anthony; Saghir, Nahid; Salphati, Laurent; Sohal, Sukhjit; Ultsch, Mark H; Valenti, Melanie; Wallweber, Heidi J A; Wan, Nan Chi; Wiesmann, Christian; Workman, Paul; Zhyvoloup, Alexander; Zvelebil, Marketa J; Shuttleworth, Stephen J

2008-09-25

Phosphatidylinositol-3-kinase (PI3K) is an important target in cancer due to the deregulation of the PI3K/ Akt signaling pathway in a wide variety of tumors. A series of thieno[3,2-d]pyrimidine derivatives were prepared and evaluated as inhibitors of PI3 kinase p110alpha. The synthesis, biological activity, and further profiling of these compounds are described. This work resulted in the discovery of 17, GDC-0941, which is a potent, selective, orally bioavailable inhibitor of PI3K and is currently being evaluated in human clinical trials for the treatment of cancer.

Variations in Glycogen Synthesis in Human Pluripotent Stem Cells with Altered Pluripotent States

PubMed Central

Chen, Richard J.; Zhang, Guofeng; Garfield, Susan H.; Shi, Yi-Jun; Chen, Kevin G.; Robey, Pamela G.; Leapman, Richard D.

2015-01-01

Human pluripotent stem cells (hPSCs) represent very promising resources for cell-based regenerative medicine. It is essential to determine the biological implications of some fundamental physiological processes (such as glycogen metabolism) in these stem cells. In this report, we employ electron, immunofluorescence microscopy, and biochemical methods to study glycogen synthesis in hPSCs. Our results indicate that there is a high level of glycogen synthesis (0.28 to 0.62 μg/μg proteins) in undifferentiated human embryonic stem cells (hESCs) compared with the glycogen levels (0 to 0.25 μg/μg proteins) reported in human cancer cell lines. Moreover, we found that glycogen synthesis was regulated by bone morphogenetic protein 4 (BMP-4) and the glycogen synthase kinase 3 (GSK-3) pathway. Our observation of glycogen bodies and sustained expression of the pluripotent factor Oct-4 mediated by the potent GSK-3 inhibitor CHIR-99021 reveals an altered pluripotent state in hPSC culture. We further confirmed glycogen variations under different naïve pluripotent cell growth conditions based on the addition of the GSK-3 inhibitor BIO. Our data suggest that primed hPSCs treated with naïve growth conditions acquire altered pluripotent states, similar to those naïve-like hPSCs, with increased glycogen synthesis. Furthermore, we found that suppression of phosphorylated glycogen synthase was an underlying mechanism responsible for altered glycogen synthesis. Thus, our novel findings regarding the dynamic changes in glycogen metabolism provide new markers to assess the energetic and various pluripotent states in hPSCs. The components of glycogen metabolic pathways offer new assays to delineate previously unrecognized properties of hPSCs under different growth conditions. PMID:26565809

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

PubMed

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

2012-01-01

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

A simple synthesis of N-perfluoroacylated and N-acylated glycals of neuraminic acid with a cyclic aminic substituent at the 4α position as possible inhibitors of sialidases.

PubMed

Rota, Paola; Allevi, Pietro; Agnolin, Irene S; Mattina, Roberto; Papini, Nadia; Anastasia, Mario

2012-04-14

A simple protocol for the synthesis of N-perfluoroacylated and N-acylated glycals of neuraminic acid, with a secondary cyclic amine (morpholine or piperidine) at the 4α position, has been set-up, starting from peracetylated N-acetylneuraminic acid methyl ester that undergoes, sequentially to its direct N-transacylation followed by a C-4 amination, a β-elimination, and a selective hydrolysis of the ester functions, without affecting the sensitive perfluorinated amide. This journal is © The Royal Society of Chemistry 2012

Synthesis of 4′-aminopantetheine and derivatives to probe aminoglycoside N-6′-acetyltransferase

PubMed Central

Yan, Xuxu; Akinnusi, T. Olukayode; Larsen, Aaron T.; Auclair, Karine

2011-01-01

Summary A convenient synthesis of 4′-aminopantetheine from commercial D-pantethine is reported. The amino group was introduced by reductive amination in order to avoid substitution at a sterically congested position. Derivatives of 4′-aminopantetheine were also prepared to evaluate the effect of O-to-N substitution on inhibitors of the resistance-causing enzyme aminoglycoside N-6′-acetyltransferase. The biological results combined with docking studies indicate that in spite of its reported unusual flexibility and ability to adopt different folds, this enzyme is highly specific for AcCoA. PMID:21225062

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

PubMed

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

2018-04-18

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

Synthesis of pyrimidine-2,4,6-trione derivatives: Anti-oxidant, anti-cancer, α-glucosidase, β-glucuronidase inhibition and their molecular docking studies.

PubMed

Barakat, Assem; Islam, Mohammad Shahidul; Al-Majid, Abdullah Mohammed; Ghabbour, Hazem A; Yousuf, Sammer; Ashraf, Mahwish; Shaikh, Nimra Naveed; Iqbal Choudhary, M; Khalil, Ruqaiya; Ul-Haq, Zaheer

2016-10-01

This paper describes a facile protocol, efficient, and environmentally benign for the synthesis a series of barbiturate acid substituted at C5 position 3a-o. The desired compounds subjected in vitro for different set of bioassays including against anti-oxidant (DPPH and super oxide scavenger assays), anti-cancer, α-glucosidase and β-glucuronidase inhibitions. Compound 3m (IC50=22.9±0.5μM) found to be potent α-glucosidase enzyme inhibitors and showed more activity than standard acarbose (IC50=841±1.73μM). Compound 3f (IC50=86.9±4.33μM) found to be moderate β-Glucuronidase enzyme inhibitors and showed activity comparatively less than the standard d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Furthermore, in sillico investigation was carried out to investigate bonding mode of barbiturate acid derivatives. Copyright © 2016 Elsevier Inc. All rights reserved.

Synthesis of methylene- and difluoromethylenephosphonate analogues of uridine-4-phosphate and 3-deazauridine-4-phosphate.

PubMed

Taylor, Scott D; Mirzaei, Farzad; Sharifi, Ali; Bearne, Stephen L

2006-12-08

Cytidine triphosphate synthetase (CTPS) catalyzes the formation of cytidine triphosphate from glutamine, uridine-5'-triphosphate (UTP), and adenosine-5'-triphosphate. Inhibitors of CTPS are of interest because of their potential as therapeutic agents. One approach to potent enzyme inhibitors is to use analogues of high energy intermediates formed during the reaction. The CTPS reaction proceeds via the high energy intermediate UTP-4-phosphate (UTP-4-P). Four novel analogues of uridine-4-phosphate (U-4-P) and 3-deazauridine-4-phosphate (3-deazaU-4-P) were synthesized in which the labile phosphate ester oxygen was replaced with a methylene and difluoromethylene group. The methylene analogue of U-4-P, compound 1, was prepared by a reaction of the sodium salt of tert-butyl diethylphosphonoacetate with protected, 4-O-activated uridine followed by acetate deprotection and decarboxylation. It was found that this compound undergoes relatively facile dephosphonylation presumably via a metaphosphate intermediate. The difluoromethylene derivative, compound 2, was prepared by electrophilic fluorination of protected 1. This compound was stable and did not undergo dephosphonylation. Synthesis of the methylene analogue of 3-deazaU-4-P, compound 3, was achieved by ribosylation of protected 4-(phosphonomethyl)-2-hydroxypyridine. Electrophilic fluorination was also employed in the preparation of protected 4-(phosphonodifluoromethyl)-2-hydroxypyridine which was used as the key building block in the synthesis of difluoro derivative 4. These compounds represent the first examples of a nucleoside in which the base has been chemically modified with a methylene or difluormethylenephosphonate group.

Phytochelatin synthesis and glutathione levels in response to heavy metals in tomato cells.

PubMed

Scheller, H V; Huang, B; Hatch, E; Goldsbrough, P B

1987-12-01

Cell suspension cultures of tomato, Lycopersicon esculentum Mill. cv VFNT-Cherry, produce phytochelatins (poly[gamma-glutamylcysteinyl]glycines) when exposed to cadmium. The synthesis of these peptides is accompanied by a decline in cellular levels of glutathione. Buthionine sulfoximine, an inhibitor of glutathione synthesis, inhibits the sustained production of phytochelatins. However, phytochelatin synthesis can occur in the presence of buthionine sulfoximine provided that sufficient glutathione is available. These results indicate that glutathione is a substrate for phytochelatin synthesis. The protein synthesis inhibitor cycloheximide does not affect the initial production of phytochelatin.

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

PubMed

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

2002-06-13

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

Bis(morpholino-1,3,5-triazine) derivatives: potent adenosine 5'-triphosphate competitive phosphatidylinositol-3-kinase/mammalian target of rapamycin inhibitors: discovery of compound 26 (PKI-587), a highly efficacious dual inhibitor.

PubMed

Venkatesan, Aranapakam M; Dehnhardt, Christoph M; Delos Santos, Efren; Chen, Zecheng; Dos Santos, Osvaldo; Ayral-Kaloustian, Semiramis; Khafizova, Gulnaz; Brooijmans, Natasja; Mallon, Robert; Hollander, Irwin; Feldberg, Larry; Lucas, Judy; Yu, Ker; Gibbons, James; Abraham, Robert T; Chaudhary, Inder; Mansour, Tarek S

2010-03-25

The PI3K/Akt signaling pathway is a key pathway in cell proliferation, growth, survival, protein synthesis, and glucose metabolism. It has been recognized recently that inhibiting this pathway might provide a viable therapy for cancer. A series of bis(morpholino-1,3,5-triazine) derivatives were prepared and optimized to provide the highly efficacious PI3K/mTOR inhibitor 1-(4-{[4-(dimethylamino)piperidin-1-yl]carbonyl}phenyl)-3-[4-(4,6-dimorpholin-4-yl-1,3,5-triazin-2-yl)phenyl]urea 26 (PKI-587). Compound 26 has shown excellent activity in vitro and in vivo, with antitumor efficacy in both subcutaneous and orthotopic xenograft tumor models when administered intravenously. The structure-activity relationships and the in vitro and in vivo activity of analogues in this series are described.

Rapid synthesis of triazine inhibitors of inosine monophosphate dehydrogenase.

PubMed

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

2002-08-19

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

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

PubMed

Pettersson, Mariell; Quant, Maria; Min, Jaeki; Iconaru, Luigi; Kriwacki, Richard W; Waddell, M Brett; Guy, R Kiplin; Luthman, Kristina; Grøtli, Morten

2015-01-01

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

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

PubMed Central

Pettersson, Mariell; Quant, Maria; Min, Jaeki; Iconaru, Luigi; Kriwacki, Richard W.; Waddell, M. Brett; Guy, R. Kiplin; Luthman, Kristina; Grøtli, Morten

2015-01-01

The transcription factor p53 is the main tumour suppressor in cells and many cancer types have p53 mutations resulting in a loss of its function. In tumours that retain wild-type p53 function, p53 activity is down-regulated by MDM2 (human murine double minute 2) via a direct protein—protein interaction. We have designed and synthesised two series of 2,5-diketopiperazines as inhibitors of the MDM2-p53 interaction. The first set was designed to directly mimic the α-helical region of the p53 peptide, containing key residues in the i, i+4 and i+7 positions of a natural α-helix. Conformational analysis indicated that 1,3,6-trisubstituted 2,5-diketopiperazines were able to place substituents in the same spatial orientation as an α-helix template. The key step of the synthesis involved the cyclisation of substituted dipeptides. The other set of tetrasubstituted 2,5-diketopiperazines were designed based on structure-based docking studies and the Ugi multicomponent reaction was used for the synthesis. This latter set comprised the most potent inhibitors which displayed micromolar IC50-values in a biochemical fluorescence polarisation assay. PMID:26427060

Chiral-catalyst-based convergent synthesis of HIV protease inhibitor GRL-06579A.

PubMed

Mihara, Hisashi; Sohtome, Yoshihiro; Matsunaga, Shigeki; Shibasaki, Masakatsu

2008-02-01

Catalytic asymmetric synthesis of GRL-06579A (1), an HIV-1 protease inhibitor effective against multi-protease-inhibitor-resistant viruses, is described. A convergent strategy that utilizes heterobimetallic multifunctional catalysts developed in our group is a key feature of the synthesis. The chirality of the bicyclic tetrahydrofuran unit of 1 was introduced through Al-Li-bis(binaphthoxide) (ALB) catalyst-controlled Michael addition of dimethyl malonate to racemic 4-O-protected cyclopentenone. ALB afforded not only the trans adduct with up to 96% ee from a matched substrate through kinetic resolution, but also the cis adduct with 99% ee through a catalyst-controlled Michael addition to a mismatched substrate. The Michael addition to produce the unusual cis adduct is described in detail. The framework of the bicyclic tetrahydrofuran was constructed by an intramolecular oxy-Michael reaction. The amino alcohol unit was constructed by an La-Li3-tris(binaphthoxide) (LLB)-catalyzed diastereoselective nitroaldol reaction of N-Boc aldehyde (Boc = tert-butoxycarbonyl) derived from L-phenylalanine. LLB promoted the nitroaldol reaction without racemization of the chiral aldehyde to give the nitroaldol adduct in 85% yield and with 93:7 diastereoselectivity and over 99% ee.

Rhodium enalcarbenoids: direct synthesis of indoles by rhodium(II)-catalyzed [4+2] benzannulation of pyrroles.

PubMed

Dawande, Sudam Ganpat; Kanchupalli, Vinaykumar; Kalepu, Jagadeesh; Chennamsetti, Haribabu; Lad, Bapurao Sudam; Katukojvala, Sreenivas

2014-04-14

Disclosed herein is the design of an unprecedented electrophilic rhodium enalcarbenoid which results from rhodium(II)-catalyzed decomposition of a new class of enaldiazo compounds. The synthetic utility of these enalcarbenoids has been successfully demonstrated in the first transition-metal-catalyzed [4+2] benzannulation of pyrroles, thus leading to substituted indoles. The new benzannulation has been applied to the efficient synthesis of the natural product leiocarpone as well as a potent adipocyte fatty-acid binding protein inhibitor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cyclo-oxygenase-2 contributes to constitutive prostanoid production in rat kidney and brain

PubMed Central

2005-01-01

Cyclo-oxygenases (COXs) catalyse the synthesis of PGH2 (prostaglandin H2), which serves as the common substrate for the production of PGE2, PGD2, PGF2α, prostacyclin (or PGI2) and TXs (thromboxanes). While COX-1 is the major isoform responsible for prostanoid synthesis in healthy tissues, little information is available on the contribution of constitutive COX-2 to the various prostanoid synthetic pathways under non-inflammatory conditions. To evaluate further the role of COX-2 in prostanoid biosynthesis, rats were acutely treated with the selective COX-1 inhibitor SC-560 [5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole] or the selective COX-2 inhibitors MF tricyclic [3-(3,4-difluorophenyl)-4-(4-(methylsulphonyl)phenyl)-2-(5H)-furanone] and DFU [5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl)phenyl-2-(5H)-furanone]. Selected tissues were then processed for a complete analysis of their prostanoid content by liquid chromatography MS. Whereas the treatment with SC-560 caused a 60–70% inhibition in the total prostanoid content of most tissues examined, a significant decrease (35–50%) in total prostanoid content following selective COX-2 inhibition was solely detected for kidney and brain tissues. Analysis of the individual prostanoids reveals significant inhibition of 6-oxo-PGF1α, PGE2, PGD2, PGF2α and TXB2 in the kidney and inhibition of all these prostanoids with the exception of PGD2 in the forebrain. These results demonstrate that constitutively expressed COX-2 contributes to the production of prostanoids in kidney and brain for each of the PGE2, PGI2 and TXB2 pathways under non-inflammatory conditions. Approaches to modulate inflammation through specific inhibition of terminal synthases, such as mPGES-1 (microsomal PGE2 synthase-1), thus have the potential to differ from COX-2 inhibitors and non-selective non-steroidal anti-inflammatory drugs with regard to effects on constitutive prostanoid synthesis and on renal function. PMID:16008526

Estimation of in vitro activity of tuberoinfundibular dopaminergic neurons by measurement of DOPA synthesis in the median eminence of hypothalamic slices.

PubMed

Arita, J; Kimura, F

1984-12-01

A new method for estimation of in vitro neurosecretory activity of tuberoinfundibular dopaminergic (TIDA) neurons was developed by measuring the rate of synthesis of dihydroxyphenylalanine (DOPA) in the median eminence of hypothalamic slices. Sagittal hypothalamic slices of ovariectomized rats were incubated in a medium containing 3-hydroxybenzylhydrazine (NSD 1015), an inhibitor of DOPA decarboxylase. DOPA accumulated in the median eminence following incubation with NSD 1015 was determined by high-performance liquid chromatography with electro-chemical detection. The amount of DOPA accumulated in vitro in the median eminence was maximal in a medium containing 10 mM NSD 1015 and linear up to 120 min at 37 degrees C. Increasing the concentration of tyrosine in medium stimulated the synthesis of DOPA in the median eminence. The synthesis of DOPA was blocked by 1 mM alpha-methyltyrosine, an inhibitor of tyrosine hydroxylase. The rate of in vitro synthesis of DOPA in the median eminence was 33% of that of in vivo synthesis. Incubation in a medium containing 50 mM K+ to depolarize neurons caused a 2.4-fold increase in DOPA synthesis in the median eminence. The high K+-induced increase in DOPA synthesis was blocked by omission of Ca2+ and addition of 1 mM EGTA into the medium, suggesting Ca2+ dependency of depolarization-activated DOPA synthesis. These results indicate that this in vitro assay is a useful means to study the regulatory mechanisms of TIDA neurons.

Design, synthesis, biological evaluation and docking study of 5-oxo-4,5-dihydropyrano[3,2-c]chromene derivatives as acetylcholinesterase and butyrylcholinesterase inhibitors.

PubMed

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

2013-10-01

A series of fused coumarins namely 5-oxo-4,5-dihydropyrano[3,2-c]chromenes linked to N-benzylpyridinium scaffold were synthesized and evaluated as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. The 1-(4-fluorobenzyl)pyridinium derivative 6g showed the most potent anti-AChE activity (IC50 value=0.038 μM) and the highest AChE/BuChE selectivity (SI>48). The docking study permitted us to rationalize the observed structure-affinity relationships and to detect possible binding modes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

A potent IκB kinase-β inhibitor labeled with carbon-14 and deuterium.

PubMed

Latli, Bachir; Eriksson, Magnus; Hrapchak, Matt; Busacca, Carl A; Senanayake, Chris H

2016-06-30

3-Amino-4-(1,1-difluoro-propyl)-6-(4-methanesulfonyl-piperidin-1-yl)-thieno[2,3-b]pyridine-2-carboxylic acid amide (1) is a potent IκB Kinase-β (IKK-β) inhibitor. The efficient preparations of this compound labeled with carbon-14 and deuterium are described. The carbon-14 synthesis was accomplished in six radiochemical steps in 25% overall yield. The key transformations were the modified Guareschi-Thorpe condensation of 2-cyano-(14) C-acetamide and a keto-ester followed by chlorination to 2,6-dichloropyridine derivative in one pot. The isolated dichloropyridine was then converted in three steps in one pot to [(14) C]-(1). The carbon-14 labeled (1) was isolated with a specific activity of 54.3 mCi/mmol and radiochemical purity of 99.8%. The deuterium labeled (1) was obtained in eight steps and in 57% overall chemical yield using 4-hydroxypiperidine-2,2,3,3,4,5,5,6,6-(2) H9 . The final three steps of this synthesis were run in one pot. Copyright © 2016 John Wiley & Sons, Ltd.

Design, synthesis and biological evaluation of LBM-A5 derivatives as potent P-glycoprotein-mediated multidrug resistance inhibitors.

PubMed

Wu, Yuxiang; Pan, Miaobo; Dai, Yuxuan; Liu, Baomin; Cui, Jian; Shi, Wei; Qiu, Qianqian; Huang, Wenlong; Qian, Hai

2016-05-15

A novel series of P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) inhibitors with triazol-N-phenethyl-tetrahydroisoquinoline or triazol-N-ethyl-tetrahydroisoquinoline scaffold were designed and synthesized via click chemistry. Most of the synthesized compounds showed higher reversal activity than verapamil (VRP). Among them, the most potent compound 4 showed a comparable activity with the known potent P-gp inhibitor WK-X-34 with lower cytotoxicity toward K562 cells (IC50>100μM). Compared with VRP, compound 4 exhibited more potency in increasing drug accumulation in K562/A02 MDR cells. Moreover, compound 4 could significantly reverse MDR in a dose-dependent manner and also persist longer chemo-sensitizing effect than VRP with reversibility. Further mechanism studies revealed that compound 4 could remarkably increase the intracellular accumulation of Adriamycin (ADM) in K562/A02 cells as well as inhibit rhodamine-123 (Rh123) efflux from the cells. These results suggested that compound 4 may represent a promising candidate for developing P-gp-mediated MDR inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exploiting the 2-Amino-1,3,4-thiadiazole Scaffold To Inhibit Trypanosoma brucei Pteridine Reductase in Support of Early-Stage Drug Discovery

PubMed Central

2017-01-01

Pteridine reductase-1 (PTR1) is a promising drug target for the treatment of trypanosomiasis. We investigated the potential of a previously identified class of thiadiazole inhibitors of Leishmania major PTR1 for activity against Trypanosoma brucei (Tb). We solved crystal structures of several TbPTR1-inhibitor complexes to guide the structure-based design of new thiadiazole derivatives. Subsequent synthesis and enzyme- and cell-based assays confirm new, mid-micromolar inhibitors of TbPTR1 with low toxicity. In particular, compound 4m, a biphenyl-thiadiazole-2,5-diamine with IC50 = 16 μM, was able to potentiate the antitrypanosomal activity of the dihydrofolate reductase inhibitor methotrexate (MTX) with a 4.1-fold decrease of the EC50 value. In addition, the antiparasitic activity of the combination of 4m and MTX was reversed by addition of folic acid. By adopting an efficient hit discovery platform, we demonstrate, using the 2-amino-1,3,4-thiadiazole scaffold, how a promising tool for the development of anti-T. brucei agents can be obtained. PMID:28983525

Exploiting the 2-Amino-1,3,4-thiadiazole Scaffold To Inhibit Trypanosoma brucei Pteridine Reductase in Support of Early-Stage Drug Discovery.

PubMed

Linciano, Pasquale; Dawson, Alice; Pöhner, Ina; Costa, David M; Sá, Monica S; Cordeiro-da-Silva, Anabela; Luciani, Rosaria; Gul, Sheraz; Witt, Gesa; Ellinger, Bernhard; Kuzikov, Maria; Gribbon, Philip; Reinshagen, Jeanette; Wolf, Markus; Behrens, Birte; Hannaert, Véronique; Michels, Paul A M; Nerini, Erika; Pozzi, Cecilia; di Pisa, Flavio; Landi, Giacomo; Santarem, Nuno; Ferrari, Stefania; Saxena, Puneet; Lazzari, Sandra; Cannazza, Giuseppe; Freitas-Junior, Lucio H; Moraes, Carolina B; Pascoalino, Bruno S; Alcântara, Laura M; Bertolacini, Claudia P; Fontana, Vanessa; Wittig, Ulrike; Müller, Wolfgang; Wade, Rebecca C; Hunter, William N; Mangani, Stefano; Costantino, Luca; Costi, Maria P

2017-09-30

Pteridine reductase-1 (PTR1) is a promising drug target for the treatment of trypanosomiasis. We investigated the potential of a previously identified class of thiadiazole inhibitors of Leishmania major PTR1 for activity against Trypanosoma brucei ( Tb ). We solved crystal structures of several Tb PTR1-inhibitor complexes to guide the structure-based design of new thiadiazole derivatives. Subsequent synthesis and enzyme- and cell-based assays confirm new, mid-micromolar inhibitors of Tb PTR1 with low toxicity. In particular, compound 4m , a biphenyl-thiadiazole-2,5-diamine with IC 50 = 16 μM, was able to potentiate the antitrypanosomal activity of the dihydrofolate reductase inhibitor methotrexate (MTX) with a 4.1-fold decrease of the EC 50 value. In addition, the antiparasitic activity of the combination of 4m and MTX was reversed by addition of folic acid. By adopting an efficient hit discovery platform, we demonstrate, using the 2-amino-1,3,4-thiadiazole scaffold, how a promising tool for the development of anti- T. brucei agents can be obtained.

SCD1 Inhibition Causes Cancer Cell Death by Depleting Mono-Unsaturated Fatty Acids

PubMed Central

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

2012-01-01

Increased metabolism is a requirement for tumor cell proliferation. To understand the dependence of tumor cells on fatty acid metabolism, we evaluated various nodes of the fatty acid synthesis pathway. Using RNAi we have demonstrated that depletion of fatty-acid synthesis pathway enzymes SCD1, FASN, or ACC1 in HCT116 colon cancer cells results in cytotoxicity that is reversible by addition of exogenous fatty acids. This conditional phenotype is most pronounced when SCD1 is depleted. We used this fatty-acid rescue strategy to characterize several small-molecule inhibitors of fatty acid synthesis, including identification of TOFA as a potent SCD1 inhibitor, representing a previously undescribed activity for this compound. Reference FASN and ACC inhibitors show cytotoxicity that is less pronounced than that of TOFA, and fatty-acid rescue profiles consistent with their proposed enzyme targets. Two reference SCD1 inhibitors show low-nanomolar cytotoxicity that is offset by at least two orders of magnitude by exogenous oleate. One of these inhibitors slows growth of HCT116 xenograft tumors. Our data outline an effective strategy for interrogation of on-mechanism potency and pathway-node-specificity of fatty acid synthesis inhibitors, establish an unambiguous link between fatty acid synthesis and cancer cell survival, and point toward SCD1 as a key target in this pathway. PMID:22457791

Design and synthesis of N-(4-aminopyridin-2-yl)amides as B-Raf(V600E) inhibitors.

PubMed

Li, Xiaokai; Shen, Jiayi; Tan, Li; Zhang, Zhang; Gao, Donglin; Luo, Jinfeng; Cheng, Huimin; Zhou, Xiaoping; Ma, Jie; Ding, Ke; Lu, Xiaoyun

2016-06-15

B-Raf(V600E) was an effective target for the treatment of human cancers. Based on a pan-Raf inhibitor TAK-632, a series of N-(4-aminopyridin-2-yl)amide derivatives were designed as novel B-Raf(V600E) inhibitors. Detailed structure-activity studies of the compounds revealed that most of the compounds displayed potent enzymatic activity against B-Raf(V600E), and good selectivity over B-Raf(WT). One of the most promising compound 4l exhibited potent inhibitory activity with an IC50 value of 38nM for B-raf(V600E), and displayed antiproliferative activities against colo205 and HT29 cells with IC50 values of 0.136 and 0.094μM, respectively. It also displayed good selectivity on both enzymatic and cellular assays over B-Raf(WT). These inhibitors may serve as lead compounds for further developing novel B-Raf(V600E) inhibitors as anticancer drugs. Copyright © 2016 Elsevier Ltd. All rights reserved.

An expedient synthesis of N-(1-(5-mercapto-4-((substituted benzylidene)amino)-4H-1,2,4-triazol-3-yl)-2-phenylethyl)benzamides as jack bean urease inhibitors and free radical scavengers: Kinetic mechanism and molecular docking studies.

PubMed

Saeed, Aamer; Larik, Fayaz Ali; Channar, Pervaiz Ali; Mehfooz, Haroon; Ashraf, Mohammad Haseeb; Abbas, Qamar; Hassan, Mubashir; Seo, Sung-Yum

2017-11-01

In this study, some new azomethine-triazole hybrids 5a-5l derived from N-benzoyl-L-phenylalanine were synthesized and characterized. The synthesized compounds showed first-rate, urease inhibition, and compounds 5c and 5e were found to be most effective inhibitors with 0.0137 ± 0.00082 μm and 0.0183 ± 0.00068 μm, respectively (thiourea 15.151 ± 1.27 μm). The kinetic mechanism of urease inhibition revealed the compounds 5c and 5e to be non-competitive inhibitors, whereas compounds 5d and 5j were found to be of mixed-type inhibitors. Docking studies also indicated better interaction patterns with urease enzyme. The results of enzyme inhibition, kinetic mechanism and molecular docking suggest that these compounds can serve as lead compounds in the design of more effective urease inhibitors. © 2017 John Wiley & Sons A/S.

Synthesis and optimization of thiadiazole derivatives as a novel class of substrate competitive c-Jun N-terminal kinase inhibitors

PubMed Central

De, Surya K.; Chen, Vida; Stebbins, John L.; Chen, Li-Hsing; Cellitti, Jason F.; Machleidt, Thomas; Barile, Elisa; Riel-Mehan, Megan; Dahl, Russell; Yang, Li; Emdadi, Aras; Murphy, Ria; Pellecchia, Maurizio

2009-01-01

A series of thiadiazole derivatives has been designed as potential allosteric, substrate competitive inhibitors of the protein kinase JNK. We report on the synthesis, characterization and evaluation of a series of compounds that resulted in the identification of potent and selective JNK inhibitors targeting its JIP-1 docking site. PMID:20045647

Cellular Energetic Status Supervises the Synthesis of Bis-Diphosphoinositol Tetrakisphosphate Independently of AMP-Activated Protein Kinase

PubMed Central

Choi, Kuicheon; Mollapour, Elahe; Choi, Jae H.; Shears, Stephen B.

2009-01-01

Cells aggressively defend adenosine nucleotide homeostasis; intracellular biosensors detect variations in energetic status and communicate with other cellular networks to initiate adaptive responses. Here, we demonstrate some new elements of this communication process, and we show that this networking is compromised by off-target, bioenergetic effects of some popular pharmacological tools. Treatment of cells with 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), so as to simulate elevated AMP levels, reduced the synthesis of bis-diphosphoinositol tetrakisphosphate ([PP]2-InsP4), an intracellular signal that phosphorylates proteins in a kinase-independent reaction. This was a selective effect; levels of other inositol phosphates were unaffected by AICAR. By genetically manipulating cellular AMP-activated protein kinase activity, we showed that it did not mediate these effects of AICAR. Instead, we conclude that the simulation of deteriorating adenosine nucleotide balance itself inhibited [PP]2-InsP4 synthesis. This conclusion is consistent with our demonstrating that oligomycin elevated cellular [AMP] and selectively inhibited [PP]2-InsP4 synthesis without affecting other inositol phosphates. In addition, we report that the short-term increases in [PP]2-InsP4 levels normally seen during hyperosmotic stress were attenuated by 2-(2-chloro-4-iodophenylamino)-N-cyclopropylmethoxy-3,4-difluoro-benzamide (PD184352). The latter is typically considered an exquisitely specific mitogen-activated protein kinase kinase (MEK) inhibitor, but small interfering RNA against MEK or extracellular signal-regulated kinase revealed that this mitogen-activated protein kinase pathway was not involved. Instead, we demonstrate that [PP]2-InsP4 synthesis was inhibited by PD184352 through its nonspecific effects on cellular energy balance. Two other MEK inhibitors, 1,4-diamino-2,3-dicyano-1,4-bis(methylthio)butadiene (U0126) and 2′-amino-3′-methoxyflavone (PD98059), had similar off-target effects. We conclude that the levels and hence the signaling strength of [PP]2-InsP4 is supervised by cellular adenosine nucleotide balance, signifying a new link between signaling and bioenergetic networks. PMID:18460607

Bacterial fatty acid metabolism in modern antibiotic discovery.

PubMed

Yao, Jiangwei; Rock, Charles O

2017-11-01

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

The effects of estrogen receptors α- and β-specific agonists and antagonists on cell proliferation and energy metabolism in human bone cell line.

PubMed

Somjen, D; Katzburg, S; Sharon, O; Grafi-Cohen, M; Knoll, E; Stern, N

2011-02-01

In cultured human osteoblasts estradiol-17β (E2) modulated DNA synthesis, the specific activity of creatine kinase BB (CK), 12 and 15 lipoxygenase (LO) mRNA expression and formation of 12- and 15-hydroxyeicosatetraenoic acid (HETE). We now investigate the response of human bone cell line (SaOS2) to phytoestrogens and estrogen receptors (ER)-specific agonists and antagonists. Treatment of SaSO2 with E2, 2,3-bis (4-hydroxyphenyl)-propionitrile (DPN; ERβ-specific agonist), 4,4',4″-[4-propyl-(1H)-pyrazol-1,3,5-triyl] tris-phenol (PPT; ERα-specific agonist), biochainin A (BA), daidzein (D), genistein (G) and raloxifene (Ral) showed increased DNA synthesis and CK. Ral inhibited completely all stimulations except DPN and to some extent D. The ERα-specific antagonist methyl-piperidino-pyrazole (MPP) and the ERβ-specific antagonist 4-[2-phenyl-5,7-bis (tri-fluoro-methyl) pyrazolo [1,5-a]pyrimidin-3-yl] phenol (PTHPP) inhibited DNA synthesis, CK and reactive oxygen species (ROS) formation induced by estrogens according to their receptors affinity. The LO inhibitor baicaleine inhibited only E2, DPN and G's effects. E2 and Ral unlike all other compounds had no effect on ERα mRNA expression, while ERβ mRNA expression was stimulated by all compounds. All compounds modulated the expression of 12LO and 15LO mRNA, except E2, PPT and Ral for 12LO, and 12- and 15-HETE productions and stimulated ROS formation which was inhibited by NADPH oxidase inhibitors diphenyleneiodonium chloride (DPI) and N-acetyl cysteine and the estrogen inhibitor ICI. DPI did not affect hormonal-induced DNA and CK. In conclusion, we provide evidence for the separation of mediation via ERα and ERβ pathways in the effects of estrogenic compounds on osteoblasts, but the role of LO/HETE/ROS is unclear. Copyright © 2010 Wiley-Liss, Inc.

The roles of the cyclo-oxygenases types one and two in prostaglandin synthesis in human fetal membranes at term.

PubMed

Sawdy, R J; Slater, D M; Dennes, W J; Sullivan, M H; Bennett, P R

2000-01-01

The aim of this study was to determine the relative contributions of cyclo-oxygenase (COX) types 1 and 2 to prostaglandin synthesis at term. Fetal membranes were collected from 6 pregnancies after elective caesarean section at term, prior to labour. The presence of COX-1 and COX-2 protein was determined using Western analysis. The relative contributions of the two isoforms of COX to prostaglandin synthesis were determined by incubation of fetal membrane discs with either a COX-2 selective inhibitor, SC236, or a COX-1 selective inhibitor, SC560, and measurement of prostaglandin release during 24 h using enzyme-linked immuno-sorbent assay (ELISA). Both COX-1 and COX-2 protein were demonstrated in amnion and chorion-decidua. The COX-2 selective inhibitor, SC-236, significantly reduced prostaglandin synthesis, both in its COX-2 specific and higher, non-specific concentration ranges. The COX-1 selective inhibitor, SC-560, had no effect upon prostaglandin synthesis in its COX-1 specific concentration range, but did significantly reduce prostaglandin synthesis at higher, non-selective concentrations. Fetal membranes contain both COX-1 and COX-2 at term, but only COX-2 contributes towards prostaglandin synthesis. COX-2 selective NSAI drugs will be as effective as non-selective agents in inhibition of fetal membrane prostaglandin synthesis and may represent a new strategy for tocolysis. Copyright 2000 Harcourt Publishers Ltd.

Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation

PubMed Central

Nguyen Van, Tai; Hospital, Audrey; Lionne, Corinne; Jordheim, Lars P; Dumontet, Charles; Périgaud, Christian; Chaloin, Laurent

2016-01-01

Summary A series of seventeen β-hydroxyphosphonate ribonucleoside analogues containing 4-substituted-1,2,3-triazoles was synthesized and fully characterized. Such compounds were designed as potential inhibitors of the cytosolic 5’-nucleotidase II (cN-II), an enzyme involved in the regulation of purine nucleotide pools. NMR and molecular modelling studies showed that a few derivatives adopted similar structural features to IMP or GMP. Five derivatives were identified as modest inhibitors with 53 to 64% of cN-II inhibition at 1 mM. PMID:27559400

Synthesis and SAR of 1-acetanilide-4-aminopyrazole-substituted quinazolines: selective inhibitors of Aurora B kinase with potent anti-tumor activity.

PubMed

Foote, Kevin M; Mortlock, Andrew A; Heron, Nicola M; Jung, Frédéric H; Hill, George B; Pasquet, Georges; Brady, Madeleine C; Green, Stephen; Heaton, Simon P; Kearney, Sarah; Keen, Nicholas J; Odedra, Rajesh; Wedge, Stephen R; Wilkinson, Robert W

2008-03-15

A new class of 1-acetanilide-4-aminopyrazole-substituted quinazoline Aurora kinase inhibitors has been discovered possessing highly potent cellular activity. Continuous infusion into athymic mice bearing SW620 tumors of the soluble phosphate derivative 2 led to dose-proportional exposure of the des-phosphate compound 8 with a high-unbound fraction. The combination of potent cell activity and high free-drug exposure led to pharmacodynamic changes in the tumor at low doses, indicative of Aurora B-kinase inhibition and a reduction in tumor volume.

Synthesis, biological evaluation and molecular docking studies of stellatin derivatives as cyclooxygenase (COX-1, COX-2) inhibitors and anti-inflammatory agents.

PubMed

Gautam, Raju; Jachak, Sanjay M; Kumar, Vivek; Mohan, C Gopi

2011-03-15

Stellatin (4), isolated from Dysophylla stellata is a cyclooxygenase (COX) inhibitor. The present study reports the synthesis and biological evaluation of new stellatin derivatives for COX-1, COX-2 inhibitory and anti-inflammatory activities. Eight derivatives showed more pronounced COX-2 inhibition than stellatin and, 17 and 21 exhibited the highest COX-2 inhibition. They also exhibited the significant anti-inflammatory activity in TPA-induced mouse ear edema assay and their anti-inflammatory effects were more than that of stellatin and indomethacin at 0.5mg/ear. The derivatives were further evaluated for antioxidant activity wherein 16 and 17 showed potent free radical scavenging activity against DPPH and ABTS radicals. Molecular docking study revealed the binding orientations of stellatin and its derivatives into the active sites of COX-1 and COX-2 and thereby helps to design the potent inhibitors. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis and biological evaluation of some N-(3-(1H-tetrazol-5-yl) phenyl)acetamide derivatives as novel non-carboxylic PTP1B inhibitors designed through bioisosteric modulation.

PubMed

Maheshwari, Neelesh; Karthikeyan, Chandrabose; Bhadada, Shraddha V; Sahi, Chandan; Verma, Amit K; Hari Narayana Moorthy, N S; Trivedi, Piyush

2018-06-08

Described herein is the synthesis and biological evaluation of a series of non-carboxylic inhibitors of Protein Tyrosine Phosphatase 1B designed using bioisosteric replacement strategy. Six N-(3-(1H-tetrazol-5-yl)phenyl)acetamide derivatives designed employing the aforementioned strategy were synthesized and screened for PTP1B inhibitory activity. Among the synthesized compounds, compound NM-03 exhibited the most potent inhibitory activity with IC 50 value of 4.48 µM. Docking studies with NM-03 revealed the key interactions with desired amino acids in the binding site of PTP1B. Furthermore, compound NM-03 also elicited good in vivo activity. Taken together, the results of this study establish N-(3-(1H-tetrazole-5-yl)phenyl)-2-(benzo[d]oxazol-2-ylthio)acetamide (NM-03) as a valuable lead molecule with great potential for PTP1B inhibitor development targeting diabetes. Copyright © 2018 Elsevier Inc. All rights reserved.

Identification of an anti-MRSA dihydrofolate reductase inhibitor from a diversity-oriented synthesis.

PubMed

Wyatt, Emma E; Galloway, Warren R J D; Thomas, Gemma L; Welch, Martin; Loiseleur, Olivier; Plowright, Alleyn T; Spring, David R

2008-10-28

The screening of a diversity-oriented synthesis library followed by structure-activity relationship investigations have led to the discovery of an anti-MRSA agent which operates as an inhibitor of Staphylococcus aureus dihydrofolate reductase.

Dynamical Systems in Neuropharmacology

DTIC Science & Technology

1992-04-15

induced hyperactivity with the selective serotonin uptake blockers fluoxetine , sertraline, or zimelidine or with the serotonin synthesis inhibitor PCPA. By...Conversely, the catecholamine synthesis inhibitor AMPT, which blocks the effects of amphetamine, did not affect the response to MDMA. We applied our scaling

Selective inhibition of influenza virus protein synthesis by inhibitors of DNA function. [UV radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1977-05-15

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

Design, Synthesis and Biological Evaluation of Novel Peptide-Like Analogues as Selective COX-2 Inhibitors

PubMed Central

Ahmaditaba, Mohammad Ali; Houshdar Tehrani, Mohammad Hassan; Zarghi, Afshin; Shahosseini, Sorayya; Daraei, Bahram

2018-01-01

A new series of peptide-like derivatives containing different aromatic amino acids and possessing pharmacophores of COX-2 inhibitors as SO2Me or N3 attached to the para position of an end phenyl ring was synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. The synthetic reactions were based on the solid phase peptide synthesis method using Wang resin. One of the analogues, i.e., compound 2d, as the representative of these series was recognized as the most effective and the highest selective COX-2 inhibitor with IC50 value of 0.08 μM and COX-2 selectivity index of 351.2, among the other synthesized compounds. Molecular docking study was operated to determine possible binding models of compound 2d to COX-2 enzyme. The study showed that the p-azido-phenyl fragment of 2d occupied inside the secondary COX-2 binding site (Arg513, and His90). The structure-activity relationships acquired disclosed that compound 2d with 4-(azido phenyl) group as pharmacophore and histidine as amino acid gives the essential geometry to provide inhibition of the COX-2 enzyme with high selectivity. Compound 2d can be a good candidate for the development of new hits of COX-2 inhibitors.

Inhibitor effects during the cell cycle in Chlamydomonas reinhardtii. Determination of transition points in asynchronous cultures

PubMed Central

1975-01-01

A wide variety of inhibitors (drugs, antibiotics, and antimetabolites) will block cell division within an ongoing cell cycle in autotrophic cultures of Chlamydomonas reinhardtii. To determine when during the cell cycle a given inhibitor is effective in preventing cell division, a technique is described which does not rely on the use of synchronous cultures. The technique permits the measurement of transition points, the cell cycle stage at which the subsequent cell division becomes insensitive to the effects of an inhibitor. A map of transition points in the cell cycle reveals that they are grouped into two broad periods, the second and fourth quarters. In general, inhibitors which block organellar DNA, RNA, and protein synthesis have second-quarter transition points, while those which inhibit nuclear cytoplasmic macromolecular synthesis have fourth-quarter transition points. The specific grouping of these transition points into two periods suggests that the synthesis of organellar components is completed midway through the cell cycle and that the synthesis of nonorganellar components required for cell division is not completed until late in the cell cycle. PMID:1176526

The in silico screening and X-ray structure analysis of the inhibitor complex of Plasmodium falciparum orotidine 5'-monophosphate decarboxylase.

PubMed

Takashima, Yasuhide; Mizohata, Eiichi; Krungkrai, Sudaratana R; Fukunishi, Yoshifumi; Kinoshita, Takayoshi; Sakata, Tsuneaki; Matsumura, Hiroyoshi; Krungkrai, Jerapan; Horii, Toshihiro; Inoue, Tsuyoshi

2012-08-01

Orotidine 5'-monophosphate decarboxylase from Plasmodium falciparum (PfOMPDC) catalyses the final step in the de novo synthesis of uridine 5'-monophosphate (UMP) from orotidine 5'-monophosphate (OMP). A defective PfOMPDC enzyme is lethal to the parasite. Novel in silico screening methods were performed to select 14 inhibitors against PfOMPDC, with a high hit rate of 9%. X-ray structure analysis of PfOMPDC in complex with one of the inhibitors, 4-(2-hydroxy-4-methoxyphenyl)-4-oxobutanoic acid, was carried out to at 2.1 Å resolution. The crystal structure revealed that the inhibitor molecule occupied a part of the active site that overlaps with the phosphate-binding region in the OMP- or UMP-bound complexes. Space occupied by the pyrimidine and ribose rings of OMP or UMP was not occupied by this inhibitor. The carboxyl group of the inhibitor caused a dramatic movement of the L1 and L2 loops that play a role in the recognition of the substrate and product molecules. Combining part of the inhibitor molecule with moieties of the pyrimidine and ribose rings of OMP and UMP represents a suitable avenue for further development of anti-malarial drugs.

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

PubMed

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

2003-10-20

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

Diastereoselective synthesis and molecular docking studies of novel fused tetrahydropyridine derivatives as new inhibitors of HIV protease

NASA Astrophysics Data System (ADS)

Mohammadi, Ali A.; Taheri, Salman; Amouzegar, Ali; Ahdenov, Reza; Halvagar, Mohammad Reza; Sadr, Ahmad Shahir

2017-07-01

An efficient one-pot, catalyst-free, and four-components procedure for the synthesis of novel 10b-hydroxy-4-nitro-5-phenyl-2,3,5,5a-tetrahydro-1H-imidazo[1,2-a]indeno[2,1-e]pyridin-6(10bH)-one derivatives from corresponding diamine, nitro ketene dithioacetal, aldehydes and 1,3-indandione in ethanol has been achieved upon a Knoevenagel condensation-Michael addition-tautomerism-cyclisation sequence. All the newly synthesized compounds were screened for molecular docking studies. Molecular docking studies were carried out using the crystal structure of HIV protease enzyme. Some of the compounds obtain minimum binding energy and good affinity toward the active pocket of HIV protease enzyme in compare with Saquinavir as a standard HIV protease inhibitor.

Acute effects of moclobemide and deprenyl on 5-HT synthesis rates in the rat brain: An autoradiographic study.

PubMed

Nishi, Kyoko; Mück-Seler, Dorotea; Hasegawa, Shu; Watanabe, Arata; Diksic, Mirko

2006-10-16

Serotonin (5-HT), norepinephrine (NE) and dopamine (DA) released from nerve terminals in the brain are primarily removed from the synaptic cleft by a reuptake mechanism. In part, the homeostasis is maintained by monoamine oxidase (MAO) deamination achieved primarily intracellularly. The present study's aim was to examine the effect of the acute administration of the MAO inhibitors, moclobemide (a MAO-A inhibitor) and deprenyl (a MAO-B inhibitor), on 5-HT synthesis rates, measured in discrete regions of the rat brain by an autoradiographic method, using alpha-[14C]methyl-l-tryptophan as a tracer. MAO inhibitors have different effects on 5-HT synthesis rates in the cell bodies and areas of the nerve terminals. Moclobemide (10 mg/kg, i.p. 30 min before the tracer injection) and deprenyl (3 mg/kg, i.p. 2 h before the tracer injection) decreased the 5-HT synthesis rates in the dorsal (-18% and -22%) and median (-22% and -33%) raphe, respectively. Moclobemide also significantly decreased 5-HT synthesis in the entire nerve terminal areas investigated. The reductions were between 23% (cingulate cortex) and 50% (locus coeruleus). Deprenyl did not significantly affect 5-HT synthesis in the nerve terminals. The present results suggest that MAO-A, and to a lesser extent, MAO-B, are involved in the regulation of 5-HT synthesis in the rat brain. The mechanism(s) of MAO inhibitors' action on 5-HT synthesis in the raphe nuclei are probably related to an increase in the extraneuronal 5-HT concentration and also to the interaction between the serotonergic and catecholaminergic neurons. The reduction of 5-HT synthesis in the raphe nuclei likely occurs by an action of extracellular 5-HT via the dendritic autoreceptors with a possible contribution from the action of extracellular DA and NE. In the terminal regions, the most likely mechanism is via the presynaptic autoreceptors through which elevated extraneuronal 5-HT acts on synthesis control. However, there is also a possibility that the elevation in intraneuronal 5-HT directly inhibits its synthesis, especially following deprenyl treatment. A great influence of moclobemide on 5-HT synthesis could be related to its antidepressant action.

Contribution of vasoactive eicosanoids and nitric oxide production to the effect of selective cyclooxygenase-2 inhibitor, NS-398, on endotoxin-induced hypotension in rats.

PubMed

Tunctan, Bahar; Korkmaz, Belma; Cuez, Tuba; Kemal Buharalioglu, C; Sahan-Firat, Seyhan; Falck, John; Malik, Kafait U

2010-11-01

Our previous studies with the use of non-selective cyclooxygenase (COX) inhibitor, indomethacin, demonstrated that prostanoids produced during endotoxaemia increase inducible nitric oxide synthase (iNOS) protein expression and nitric oxide synthesis, and decrease cyctochrome P450 (CYP) 4A1 protein expression and CYP 4A activity. The results suggest that dual inhibition of iNOS and COX by indomethacin restores blood pressure presumably due to increased production of 20-hydroxyeicosatetraenoic acid (20-HETE) derived from CYP 4A in endotoxaemic rats. The present study examined whether increased levels of vasoconstrictor eicosanoids, 20-HETE, prostaglandin F(2α) (PGF(2α) )and thromboxane A(2) (TxA(2) ), would contribute to the effect of selective COX-2 inhibition to prevent endotoxin (ET)-induced fall in blood pressure associated with an increase in the production of vasodilator prostanoids, prostaglandin I(2) (PGI(2) ) and prostaglandin E(2) (PGE(2) ) and nitric oxide synthesis. Mean arterial blood pressure fell by 31 mmHg and heart rate (HR) rose by 90 beats/min. in male Wistar rats treated with ET (10 mg/kg, i.p.). The fall in mean arterial pressure and increase in HR were associated with increased levels of 6-keto-prostaglandin F(1α) (6-keto-PGF(1α) ), PGE(2) , TxB(2) , and nitrite in the serum, kidney, heart, thoracic aorta and/or superior mesenteric artery. Systemic and renal 20-HETE and PGF(2α) levels were also decreased in endotoxaemic rats. These effects of ET were prevented by a selective COX-2 inhibitor, N-(2-cyclohexyloxy-4-nitrophenyl)methansulphonamide (10 mg/kg, i.p.), given 1 hr after injection of ET. These data suggest that an increase in 20-HETE and PGF(2α) levels associated with decreased production of PGI(2) , PGE(2) , and TxA(2) , and nitric oxide synthesis contributes to the effect of selective COX-2 inhibitor to prevent the hypotension during rat endotoxaemia. © 2010 The Authors. Basic & Clinical Pharmacology & Toxicology © 2010 Nordic Pharmacological Society.

Inhibitors incorporating zinc-binding groups target the GlcNAc-PI de-N-acetylase in Trypanosoma brucei, the causative agent of African sleeping sickness.

PubMed

Abdelwahab, Nuha Z; Crossman, Arthur T; Sullivan, Lauren; Ferguson, Michael A J; Urbaniak, Michael D

2012-03-01

Disruption of glycosylphosphatidylinositol biosynthesis is genetically and chemically validated as a drug target against the protozoan parasite Trypanosoma brucei, the causative agent of African sleeping sickness. The N-acetylglucosamine-phosphatidylinositol de-N-acetylase (deNAc) is a zinc metalloenzyme responsible for the second step of glycosylphosphatidylinositol biosynthesis. We recently reported the synthesis of eight deoxy-2-C-branched monosaccharides containing carboxylic acid, hydroxamic acid, or N-hydroxyurea substituents at the C2 position that may act as zinc-binding groups. Here, we describe the synthesis of a glucocyclitol-phospholipid incorporating a hydroxamic acid moiety and report the biochemical evaluation of the monosaccharides and the glucocyclitol-phospholipid as inhibitors of the trypanosome deNAc in the cell-free system and against recombinant enzyme. Monosaccharides with carboxylic acid or hydroxamic acid substituents were found to be the inhibitors of the trypanosome deNAc with IC(50) values 0.1-1.5mM and the glucocyclitol-phospholipid was found to be a dual inhibitor of the deNAc and the α1-4-mannose transferase with an apparent IC(50)= 19±0.5μm. © 2011 John Wiley & Sons A/S.

Development of a new class of aromatase inhibitors: Design, synthesis and inhibitory activity of 3-phenylchroman-4-one (isoflavanone) derivatives

PubMed Central

Bonfield, Kevin; Amato, Erica; Bankemper, Tony; Agard, Hannah; Steller, Jeffrey; Keeler, James M.; Roy, David; McCallum, Adam; Paula, Stefan; Ma, Lili

2014-01-01

Aromatase (CYP19) catalyzes the aromatization reaction of androgen substrates to estrogens, the last and rate-limiting step in estrogen biosynthesis. Inhibition of aromatase is a new and promising approach to treat hormone-dependent breast cancer. We present here the design and development of isoflavanone derivatives as potential aromatase inhibitors. Structural modifications were performed on the A and B rings of isoflavanones via microwave-assisted, gold-catalyzed annulation reactions of hydroxyaldehydes and alkynes. The in vitro aromatase inhibition of these compounds was determined by fluorescence-based assays utilizing recombinant human aromatase (baculovirus/insect cell-expressed). The compounds 3-(4-phenoxyphenyl)chroman-4-one (1h), 6-methoxy-3-phenylchroman-4-one (2a) and 3-(pyridin-3-yl)chroman-4-one (3b) exhibited potent inhibitory effects against aromatase with IC50 values of 2.4 μM, 0.26 μM and 5.8 μM, respectively. Docking simulations were employed to investigate crucial enzyme/inhibitor interactions such as hydrophobic interactions, hydrogen bonding and heme iron coordination. This report provides useful information on aromatase inhibition and serves as a starting point for the development of new flavonoid aromatase inhibitors. PMID:22444875

Acetyl-CoA carboxylase-alpha inhibitor TOFA induces human cancer cell apoptosis.

PubMed

Wang, Chun; Xu, Canxin; Sun, Mingwei; Luo, Dixian; Liao, Duan-Fang; Cao, Deliang

2009-07-31

Acetyl-CoA carboxylase-alpha (ACCA) is a rate-limiting enzyme in long chain fatty acid synthesis, playing a critical role in cellular energy storage and lipid synthesis. ACCA is upregulated in multiple types of human cancers and small interfering RNA-mediated ACCA silencing in human breast and prostate cancer cells results in oxidative stress and apoptosis. This study reports for the first time that TOFA (5-tetradecyloxy-2-furoic acid), an allosteric inhibitor of ACCA, is cytotoxic to lung cancer cells NCI-H460 and colon carcinoma cells HCT-8 and HCT-15, with an IC(50) at approximately 5.0, 5.0, and 4.5 microg/ml, respectively. TOFA at 1.0-20.0 microg/ml effectively blocked fatty acid synthesis and induced cell death in a dose-dependent manner. The cell death was characterized with PARP cleavage, DNA fragmentation, and annexin-V staining, all of which are the features of the apoptosis. Supplementing simultaneously the cells with palmitic acids (100 microM), the end-products of the fatty acid synthesis pathway, prevented the apoptosis induced by TOFA. Taken together, these data suggest that TOFA is a potent cytotoxic agent to lung and colon cancer cells, inducing apoptosis through disturbing their fatty acid synthesis.

Acetyl-CoA Carboxylase-α Inhibitor TOFA Induces Human Cancer Cell Apoptosis

PubMed Central

Wang, Chun; Xu, Canxin; Sun, Mingwei; Luo, Dixian; Liao, Duan-fang; Cao, Deliang

2009-01-01

Acetyl-CoA carboxylase-α (ACCA) is a rate-limiting enzyme in long chain fatty acid synthesis, playing a critical role in cellular energy storage and lipid synthesis. ACCA is upregulated in multiple types of human cancers and small interfering RNA-mediated ACCA silencing in human breast and prostate cancer cells results in oxidative stress and apoptosis. This study reports for the first time that TOFA (5-tetradecyloxy-2-furoic acid), an allosteric inhibitor of ACCA, is cytotoxic to lung cancer cells NCI-H460 and colon carcinoma cells HCT-8 and HCT-15, with an IC50 at approximately 5.0, 5.0, and 4.5 μg/ml, respectively. TOFA at 1.0–20.0 μg/ml effectively blocked fatty acid synthesis and induced cell death in a dose-dependent manner. The cell death was characterized with PARP cleavage, DNA fragmentation, and annexin-V staining, all of which are the features of the apoptosis. Supplementing simultaneously the cells with palmitic acids (100 μM), the end-products of the fatty acid synthesis pathway, prevented the apoptosis induced by TOFA. Taken together, these data suggest that TOFA is a potent cytotoxic agent to lung and colon cancer cells, inducing apoptosis through disturbing their fatty acid synthesis. PMID:19450551

Synthesis, biological evaluation and docking studies of 2,3-dihydroquinazolin-4(1H)-one derivatives as inhibitors of cholinesterases.

PubMed

Sarfraz, Muhammad; Sultana, Nargis; Rashid, Umer; Akram, Muhammad Safwan; Sadiq, Abdul; Tariq, Muhammad Ilyas

2017-02-01

In search of potent inhibitors of cholinesterases, we have synthesized and evaluate a number of 2,3-dihydroquinazolin-4(1H)-one derivatives. The synthetic approach provided an efficient synthesis of the target molecules with excellent yield. All the tested compounds showed activity against both the enzymes in micromolar range. In many case, the inhibition of both enzymes are higher than or comparable to the standard drug galatamine. With the selectivity index of 2.3 for AChE, compound 5f can be considered as a potential lead compound with a feature of dual AChE/BChE inhibition with IC 50 =1.6±0.10μM (AChE) and 3.7±0.18μM (BChE). Binding modes of the synthesized compounds were explored by using GOLD (Genetic Optimization for Ligand Docking) suit v5.4.1. The computed binding modes of these compounds in the active site of AChE and BChE provide an insight into the mechanism of inhibition of these two enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

Cyclohex-1-ene carboxylic acids: synthesis and biological evaluation of novel inhibitors of human 5 alpha reductase.

PubMed

Baston, Eckhard; Salem, Ola I A; Hartmann, Rolf W

2003-03-01

In search of novel nonsteroidal mimics of steroidal inhibitors of 5 alpha reductase, 4-(2-phenylethyl)cyclohex-1-ene carboxylic acids 1-5 were synthesized with different substituents in para position of the phenyl ring (1: N, N-diisopropylcarbamoyl, 2: phenyl, 3: phenoxy, 4: benzoyl, and 5: benzyl). The principal synthetic approach for the desired compounds consisted of a Wittig olefination between 1, 4-dioxaspiro [4.5]-decane-8-carbaldehyde (4g and the appropriate phosphonium salts. The compounds were tested for inhibition of human 5 alpha reductase isozymes 1 and 2 using DU 145 cells and preparations from prostatic tissue, respectively. They turned out to be good inhibitors of the prostatic isozyme 2 with compound 1 being the most potent one (IC(50) = 760 nM). Isozyme 1 was only slightly inhibited. It is concluded that the novel structures are appropriate for being further optimized, aiming at the development of a novel drug for the treatment of benign prostatic hyperplasia.

Synthesis and evaluation of new thiadiazole derivatives as potential inhibitors of human carbonic anhydrase isozymes (hCA-I and hCA-II).

PubMed

Altintop, Mehlika Dilek; Ozdemir, Ahmet; Kucukoglu, Kaan; Turan-Zitouni, Gulhan; Nadaroglu, Hayrunnisa; Kaplancikli, Zafer Asim

2015-02-01

2-[[5-(2,4-Difluoro/dichlorophenylamino)-1,3,4-thiadiazol-2-yl]thio] acetophenone derivatives (3a--s) were designed as human carbonic anhydrase isozymes (hCA-I and hCA-II) inhibitors and synthesized. hCA-I and hCA-II were purified from erythrocyte cells by the affinity chromatography. The inhibitory effects of 18 newly synthesized acetophenones on hydratase activity of these isoenzymes were studied in vitro. The average IC50 values of the new compounds for hydratase activity ranged from 0.033 to 0.14 μM for hCA-I and from 0.030 to 0.11 μM for hCA-II. Among the newly synthesized compounds, 2-[[5-(2,4-dichlorophenylamino)-1,3,4-thiadiazol-2-yl]thio]-4'-bromoacetophenone (3n) can be considered as a promising hCA-II inhibitor owing to its selective and potent inhibitory effect on hCA-II.

Synthesis of galabiose-chitosan conjugate as potent inhibitor of Streptococcus suis adhesion.

PubMed

Xu, Yaozu; Fan, Hongjie; Lu, Chengping; Gao, George F; Li, Xuebing

2010-07-12

The aim of this work is to construct a safe and effective drug candidate against Streptococcus suis infection. A panel of chitosan-based polymer conjugates with branched galabiose (Galalpha1-4Gal) side chains was synthesized as inhibitors of S. suis adhesion. The synthesis was achieved by using an aldehyde-functionalized galabiose derivative to graft it onto chitosan amino groups. Structural compositions of the conjugates were verified by 1H NMR spectroscopy and CHN elemental analyses. Potent inhibitory activities of the conjugates against S. suis adhesion to human erythrocytes were determined at low nanomolar concentration by HAI assay. An SPR study revealed a high affinity binding (Kd=39.6 nM) of the conjugate with BSI-B4 lectin. By using biocompatible chitosan as the scaffold for presenting S. suis -specific galabiose units, as well as the concise route tailored for the conjugate syntheses, the present study provides a practical way for explorations of new anti- S. suis therapies.

Novel Inhibitors of Mycobacterium tuberculosis dTDP-6-deoxy-L-lyxo-4-hexulose Reductase (RmlD) Identified by Virtual Screening

PubMed Central

Wang, Yi; Hess, Tamara Noelle; Jones, Victoria; Zhou, Joe Zhongxiang; McNeil, Michael R.; McCammon, J. Andrew

2011-01-01

The complex and highly impermeable cell wall of Mycobacterium tuberculosis (Mtb) is largely responsible for the ability of the mycobacterium to resist the action of chemical therapeutics. An L-rhamnosyl residue, which occupies an important anchoring position in the Mtb cell wall, is an attractive target for novel anti-tuberculosis drugs. In this work, we report a virtual screening (VS) study targeting Mtb dTDP-deoxy-L-lyxo-4-hexulose reductase (RmlD), the last enzyme in the L-rhamnosyl synthesis pathway. Through two rounds of VS, we have identified four RmlD inhibitors with half inhibitory concentrations of 0.9-25 μM, and whole-cell minimum inhibitory concentrations of 20-200 μg/ml. Compared with our previous high throughput screening targeting another enzyme involved in L-rhamnosyl synthesis, virtual screening produced higher hit rates, supporting the use of computational methods in future anti-tuberculosis drug discovery efforts. PMID:22014548

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

PubMed

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

2013-03-20

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

Synthesis of Lysine Methyltransferase Inhibitors

NASA Astrophysics Data System (ADS)

Ye, Tao; Hui, Chunngai

2015-07-01

Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

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

PubMed

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

2011-10-15

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

PROTEASOME INHIBITOR TREATMENT REDUCED FATTY ACID, TRIACYLGLYCEROL AND CHOLESTEROL SYNTHESIS

PubMed Central

Oliva, Joan; French, Samuel W.; Li, Jun; Bardag-Gorce, Fawzia

2014-01-01

In the present study, the beneficial effects of proteasome inhibitor treatment in reducing ethanol-induced steatosis were investigated. A microarray analysis was performed on the liver of rats injected with PS-341 (Bortezomib, Velcade®), and the results showed that proteasome inhibitor treatment significantly reduced the mRNA expression of SREBP-1c, and the downstream lipogenic enzymes, such as fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), which catalyzes the carboxylation of acetyl-CoA to malonyl-CoA, the rate-limiting step in fatty acid synthesis. ELOVL6, which is responsible for fatty acids long chain elongation, was also significantly down regulated by proteasome inhibitor treatment. Moreover, PS-341 administration significantly reduced the expression of acyl-glycerol-3-phosphate acyltransferase (AGPAT), and diacylglycerol acyltransferase (DGAT), enzyme involved in triacylglycerol (TAG) synthesis. Finally, PS-341 was found to down regulate the enzymes 3-hydroxy-3-methylglutaryl-CoenzymeA synthase (HMG-CoA synthase) that is responsible for cholesterol synthesis. Proteasome inhibitor was also found to play a role in intestinal lipid adsorption because apolipoproteins A (apoA-I, apoAII, apoA-IV and ApoCIII) were down regulated by proteasome inhibitor treatment, especially ApoA-II that is known to be a marker of alcohol consumption. Proteasome inhibitor treatment also decreased apobec-1 complementation factor (ACF) leading to lower level of editing and production of ApoB protein. Moreover apolipoprotein C-III, a major component of chylomicrons was significantly down regulated. However, lipoprotein lipase (Lpl) and High density lipoprotein binding protein (Hdlbp) mRNA levels were increased by proteasome inhibitor treatment. These results suggested that proteasome inhibitor treatment could be used to reduce the alcohol-enhanced lipogenesis and alcohol-induced liver steatosis. A morphologic analysis, performed on the liver of rats fed ethanol for one month and treated with PS-341, showed that proteasome inhibitor treatment significantly decreased ethanol-induced liver steatosis. SREBP-1c, FAS and ACC were increased by ethanol feeding alone, but were significantly decreased when proteasome inhibitor was administered to rats fed ethanol. Our results also show that both mRNA and protein levels of these lipogenic enzymes, up regulated by ethanol, were then down regulated when proteasome inhibitor was administered to rats fed ethanol. It was also confirmed that alcohol feeding caused an increase in AGPAT and DGAT, which was prevented by proteasome inhibitor treatment of the animal fed ethanol. Chronic alcohol feeding did not affect the gene expression of HMG-CoA synthase. However, PS341 administration significantly reduced the HMG-CoA synthase mRNA levels, confirming the results obtained with the microarray analysis. C/EBP transcription factors alpha (CCAAT/enhancer-binding protein alpha) has been shown to positively regulate SREBP-1c mRNA expression, thus regulating lipogenesis. Proteasome inhibition caused a decrease in C/EBP alpha mRNA expression, indicating that C/EBP down regulation may be the mechanism by which proteasome inhibitor treatment reduced lipogenesis. In conclusion, our results indicate that proteasome activity is not only involved in down regulating fatty acid synthesis and triacylglycerol synthesis, but also cholesterol synthesis and intestinal lipid adsorption. Proteasome inhibitor, administrated at a non-toxic low dose, played a beneficial role in reducing lipogenesis caused by chronic ethanol feeding and these beneficial effects are obtained because of the specificity and reversibility of the proteasome inhibitor used. PMID:22445925

Inhibitors of the serotonin transporter protein (SERT): the design and synthesis of biotinylated derivatives of 3-(1,2,3,6-tetrahydro-pyridin-4-yl)-1H-indoles. High-affinity serotonergic ligands for conjugation with quantum dots.

PubMed

Tomlinson, Ian D; Mason, John N; Blakely, Randy D; Rosenthal, Sandra J

2005-12-01

There is a growing demand for compounds with specificity for the serotonin transporter protein (SERT) that can be conjugated to cadmium selenide/zinc sulfide core shell nanocrystals. This letter describes the design and synthesis of two different biotinylated SERT antagonists that can be attached to streptavidin-coated cadmium selenide/zinc sulfide core shell nanocrystals.

Identification of Novel Human Breast Carcinoma (MDA-MB-231) Cell Growth Modulators from a Carbohydrate-Based Diversity Oriented Synthesis Library.

PubMed

Lenci, Elena; Innocenti, Riccardo; Biagioni, Alessio; Menchi, Gloria; Bianchini, Francesca; Trabocchi, Andrea

2016-10-20

The application of a cell-based growth inhibition on a library of skeletally different glycomimetics allowed for the selection of a hexahydro-2 H -furo[3,2- b ][1,4]oxazine compound as candidate inhibitors of MDA-MB-231 cell growth. Subsequent synthesis of analogue compounds and preliminary biological studies validated the selection of a valuable hit compound with a novel polyhydroxylated structure for the modulation of the breast carcinoma cell cycle mechanism.

Effects of VMAT2 inhibitors lobeline and GZ-793A on methamphetamine-induced changes in dopamine release, metabolism and synthesis in vivo.

PubMed

Meyer, Andrew C; Neugebauer, Nichole M; Zheng, Guangrong; Crooks, Peter A; Dwoskin, Linda P; Bardo, Michael T

2013-10-01

Vesicular monoamine transporter-2 (VMAT2) inhibitors reduce methamphetamine (METH) reward in rats. The current study determined the effects of VMAT2 inhibitors lobeline (LOB; 1 or 3 mg/kg) and N-(1,2R-dihydroxylpropyl)-2,6-cis-di(4-methoxyphenethyl)piperidine hydrochloride (GZ-793A; 15 or 30 mg/kg) on METH-induced (0.5 mg/kg, SC) changes in extracellular dopamine (DA) and its metabolite dihydroxyphenylacetic acid (DOPAC) in the reward-relevant nucleus accumbens (NAc) shell using in vivo microdialysis. The effect of GZ-793A (15 mg/kg) on DA synthesis in tissue also was investigated in NAc, striatum, medial prefrontal cortex and orbitofrontal cortex. In NAc shell, METH produced a time-dependent increase in extracellular DA and decrease in DOPAC. Neither LOB nor GZ-793A alone altered extracellular DA; however, both drugs increased extracellular DOPAC. In combination with METH, LOB did not alter the effects of METH on DA; however, GZ-793A, which has greater selectivity than LOB for inhibiting VMAT2, reduced the duration of the METH-induced increase in extracellular DA. Both LOB and GZ-793A enhanced the duration of the METH-induced decrease in extracellular DOPAC. METH also increased tissue DA synthesis in NAc and striatum, whereas GZ-793A decreased synthesis; no effect of METH or GZ-793A on DA synthesis was found in medial prefrontal cortex or orbitofrontal cortex. These results suggest that selective inhibition of VMAT2 produces a time-dependent decrease in DA release in NAc shell as a result of alterations in tyrosine hydroxylase activity, which may play a role in the ability of GZ-793A to decrease METH reward. © 2013 International Society for Neurochemistry.

Novel multi-targeted agents for Alzheimer's disease: Synthesis, biological evaluation, and molecular modeling of novel 2-[4-(4-substitutedpiperazin-1-yl)phenyl]benzimidazoles.

PubMed

Ozadali-Sari, Keriman; Tüylü Küçükkılınç, Tuba; Ayazgok, Beyza; Balkan, Ayla; Unsal-Tan, Oya

2017-06-01

The present study describes the synthesis, pharmacological evaluation (BChE/AChE inhibition, Aβ antiaggregation, and neuroprotective effects), and molecular modeling studies of novel 2-[4-(4-substitutedpiperazin-1-yl)phenyl]benzimidazole derivatives. The alkyl-substituted derivatives exhibited selective inhibition on BChE with varying efficiency. Compounds 3b and 3d were found to be the most potent inhibitors of BChE with IC 50 values of 5.18 and 5.22μM, respectively. The kinetic studies revealed that 3b is a partial non-competitive BChE inhibitor. Molecular modeling studies also showed that the alkyl-substituted derivatives were able to reach the catalytic anionic site of the BChE. The compounds with an inhibitory effect on BChE were subsequently screened for their Aβ antiaggregating and neuroprotective activities. Compounds 3a and 3b exerted a potential neuroprotective effect against H 2 O 2 and Aβ-induced cytotoxicity in SH-SY5Y cells. Collectively, 3b was found as the most promising compound for the development of multi-target directed ligands against Alzheimer's disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Differential positioning of C(4) mesophyll and bundle sheath chloroplasts: recovery of chloroplast positioning requires the actomyosin system.

PubMed

Kobayashi, Hiroaki; Yamada, Masahiro; Taniguchi, Mitsutaka; Kawasaki, Michio; Sugiyama, Tatsuo; Miyake, Hiroshi

2009-01-01

In C(4) plants, bundle sheath (BS) chloroplasts are arranged in the centripetal position or in the centrifugal position, although mesophyll (M) chloroplasts are evenly distributed along cell membranes. To examine the molecular mechanism for the intracellular disposition of these chloroplasts, we observed the distribution of actin filaments in BS and M cells of the C(4) plants finger millet (Eleusine coracana) and maize (Zea mays) using immunofluorescence. Fine actin filaments encircled chloroplasts in both cell types, and an actin network was observed adjacent to plasma membranes. The intracellular disposition of both chloroplasts in finger millet was disrupted by centrifugal force but recovered within 2 h in the dark. Actin filaments remained associated with chloroplasts during recovery. We also examined the effects of inhibitors on the rearrangement of chloroplasts. Inhibitors of actin polymerization, myosin-based activities and cytosolic protein synthesis blocked migration of chloroplasts. In contrast, a microtubule-depolymerizing drug had no effect. These results show that C(4) plants possess a mechanism for keeping chloroplasts in the home position which is dependent on the actomyosin system and cytosolic protein synthesis but not tubulin or light.

Synthesis, biological evaluation and molecular modeling studies of imidazo[1,2-a]pyridines derivatives as protein kinase inhibitors.

PubMed

Lawson, Marie; Rodrigo, Jordi; Baratte, Blandine; Robert, Thomas; Delehouzé, Claire; Lozach, Olivier; Ruchaud, Sandrine; Bach, Stéphane; Brion, Jean-Daniel; Alami, Mouad; Hamze, Abdallah

2016-11-10

We report here the synthesis, the biological evaluation and the molecular modeling studies of new imidazo[1,2-a]pyridines derivatives designed as potent kinase inhibitors. This collection was obtained from 2-aminopyridines and 2-bromoacetophenone which afforded final compound in only one step. The bioactivity of this family of new compounds was tested using protein kinase and ATP competition assays. The structure-activity relationship (SAR) revealed that six compounds inhibit DYRK1A and CLK1 at a micromolar range. Docking studies provided possible explanations that correlate with the SAR data. The most active compound 4c inhibits CLK1 (IC50 of 0.7 μM) and DYRK1A (IC50 of 2.6 μM). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Modulation of leukocyte adhesion in rat mesenteric venules by aspirin and salicylate.

PubMed

Asako, H; Kubes, P; Wallace, J; Wolf, R E; Granger, D N

1992-07-01

Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, and number of adherent and emigrated leukocytes were measured in postcapillary venules both before and during superfusion of rat mesentery with either aspirin or sodium salicylate. In some experiments, animals were treated with either a leukotriene (LT)-synthesis inhibitor (L-663,536), an LTD4 antagonist (MK-571), an LTB4 antagonist (SC-41930), misoprostol, or prostaglandin (PG) I2, then the aspirin protocol was repeated. Superfusion of aspirin but not sodium salicylate resulted in increased leukocyte adherence and a reduced leukocyte rolling velocity but did not affect leukocyte emigration. Aspirin-induced leukocyte adhesion was effectively prevented by the LT-synthesis inhibitor and LTB4 antagonist but not by the LTD4 antagonist. Misoprostol and PGI2 also prevented the aspirin-induced adhesion responses. Superfusion of the mesentery with either platelet-activating factor (PAF) or LTB4 enhanced leukocyte adherence and emigration while reducing leukocyte rolling velocity. Sodium salicylate prevented all of the adhesion responses elicited by LTB4. Although salicylate did not affect the PAF-induced leukocyte adherence and rolling responses, it completely prevented the increased leukocyte emigration. These results indicate that aspirin promotes, whereas sodium salicylate inhibits, leukocyte-endothelial cell adhesive interactions at therapeutically relevant concentrations.

Cell proliferation and progesterone synthesis depend on lipid metabolism in bovine granulosa cells.

PubMed

Elis, Sebastien; Desmarchais, Alice; Maillard, Virginie; Uzbekova, Svetlana; Monget, Philippe; Dupont, Joëlle

2015-03-15

In dairy cows, lipids are essential to support energy supplies for all biological functions, especially during early lactation. Lipid metabolism is crucial for sustaining proper reproductive function. Alteration of lipid metabolism impacts follicular development and affects oocyte developmental competence. Indeed, nonesterified fatty acids are able to decrease granulosa cell (GC) proliferation and affect estradiol synthesis, thus potentially affecting follicular growth and viability. The objective of this study was to assess the impact of lipid metabolism on bovine GCs, through the use of the lipid metabolism inhibitors etomoxir, an inhibitor of fatty acid (FA) oxidation through inhibition of carnitine palmitoyl transferase 1 (CPT1), and C75, an inhibitor of FA synthesis through inhibition of fatty acid synthase. We showed that etomoxir and C75 significantly inhibited DNA synthesis in vitro; C75 also significantly decreased progesterone synthesis. Both inhibitors significantly reduced AMPK (5' adenosine monophosphate-activated protein kinase) and acetyl-CoA carboxylase phosphorylation. Etomoxir also affected the AKT (protein kinase B) signaling pathway. Combined, these data suggest that both FA oxidation and synthesis are important for the bovine GCs to express a proliferative and steroidogenic phenotype and, thus, for sustaining follicular growth. Despite these findings, it is important to note that the changes caused by the inhibitors of FA metabolism on GCs in vitro are globally mild, suggesting that lipid metabolism is not as critical in GCs as was observed in the oocyte-cumulus complex. Further studies are needed to investigate the detailed mechanisms by which lipid metabolism interacts with GC functions. Copyright © 2015 Elsevier Inc. All rights reserved.

Structure-based design, synthesis, molecular docking study and biological evaluation of 1,2,4-triazine derivatives acting as COX/15-LOX inhibitors with anti-oxidant activities.

PubMed

Khoshneviszadeh, Mehdi; Shahraki, Omolbanin; Khoshneviszadeh, Mahsima; Foroumadi, Alireza; Firuzi, Omidreza; Edraki, Najmeh; Nadri, Hamid; Moradi, Alireza; Shafiee, Abbas; Miri, Ramin

2016-12-01

A set of 1,2,4-triazine derivatives were designed as cyclooxygenase-2 (COX-2) inhibitors. These compounds were synthesized and screened for inhibition of cyclooxygenases (COX-1 and COX-2) based on a cellular assay using human whole blood (HWB) and lipoxygenase (LOX-15) that are key enzymes in inflammation. The results showed that 3-(2-(benzo[d][1,3]dioxol-5-ylmethylene)hydrazinyl)-5,6-bis(4-methoxyphenyl)-1,2,4-triazine (G11) was identified as the most potent COX-2 inhibitor (78%) relative to COX-1 (50%). Ferric reducing anti-oxidant power (FRAP) assay revealed that compound G10 possesses the highest anti-oxidant activity. The compound G3 with IC50 value of 124 μM was the most potent compound in LOX inhibitory assay. Molecular docking was performed and a good agreement was observed between computational and experimental results.

Design, synthesis, and biological evaluation of novel dipeptide-type SARS-CoV 3CL protease inhibitors: structure-activity relationship study.

PubMed

Thanigaimalai, Pillaiyar; Konno, Sho; Yamamoto, Takehito; Koiwai, Yuji; Taguchi, Akihiro; Takayama, Kentaro; Yakushiji, Fumika; Akaji, Kenichi; Kiso, Yoshiaki; Kawasaki, Yuko; Chen, Shen-En; Naser-Tavakolian, Aurash; Schön, Arne; Freire, Ernesto; Hayashi, Yoshio

2013-07-01

This work describes the design, synthesis, and evaluation of low-molecular weight peptidic SARS-CoV 3CL protease inhibitors. The inhibitors were designed based on the potent tripeptidic Z-Val-Leu-Ala(pyrrolidone-3-yl)-2-benzothiazole (8; Ki = 4.1 nM), in which the P3 valine unit was substituted with a variety of distinct moieties. The resulting series of dipeptide-type inhibitors displayed moderate to good inhibitory activities against 3CL(pro). In particular, compounds 26m and 26n exhibited good inhibitory activities with Ki values of 0.39 and 0.33 μM, respectively. These low-molecular weight compounds are attractive leads for the further development of potent peptidomimetic inhibitors with pharmaceutical profiles. Docking studies were performed to model the binding interaction of the compound 26m with the SARS-CoV 3CL protease. The preliminary SAR study of the peptidomimetic compounds with potent inhibitory activities revealed several structural features that boosted the inhibitory activity: (i) a benzothiazole warhead at the S1' position, (ii) a γ-lactam unit at the S1-position, (iii) an appropriately hydrophobic leucine moiety at the S2-position, and (iv) a hydrogen bond between the N-arylglycine unit and a backbone hydrogen bond donor at the S3-position. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Discovery of novel selenium derivatives as Pin1 inhibitors by high-throughput screening

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subedi, Amit; Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570; Shimizu, Takeshi

2016-06-03

Peptidyl prolyl cis/trans isomerization by Pin1 regulates various oncogenic signals during cancer progression, and its inhibition through multiple approaches has established Pin1 as a therapeutic target. However, lack of simplified screening systems has limited the discovery of potent Pin1 inhibitors. We utilized phosphorylation-dependent binding of Pin1 to its specific substrate to develop a screening system for Pin1 inhibitors. Using this system, we screened a chemical library, and identified a novel selenium derivative as Pin1 inhibitor. Based on structure-activity guided chemical synthesis, we developed more potent Pin1 inhibitors that inhibited cancer cell proliferation. -- Highlights: •Novel screening for Pin1 inhibitors basedmore » on Pin1 binding is developed. •A novel selenium compound is discovered as Pin1 inhibitor. •Activity guided chemical synthesis of selenium derivatives resulted potent Pin1 inhibitors.« less

Synthesis and evaluation of biaryl derivatives for structural characterization of selective monoamine oxidase B inhibitors toward Parkinson's disease therapy.

PubMed

Yeon, Seul Ki; Choi, Ji Won; Park, Jong-Hyun; Lee, Ye Rim; Kim, Hyeon Jeong; Shin, Su Jeong; Jang, Bo Ko; Kim, Siwon; Bahn, Yong-Sun; Han, Gyoonhee; Lee, Yong Sup; Pae, Ae Nim; Park, Ki Duk

2018-01-01

Benzyloxyphenyl moiety is a common structure of highly potent, selective and reversible inhibitors of monoamine oxidase B (MAO-B), safinamide and sembragiline. We synthesized 4-(benzyloxy)phenyl and biphenyl-4-yl derivatives including halogen substituents on the terminal aryl unit. In addition, we modified the carbon linker between amine group and the biaryl linked unit. Among synthesized compounds, 12c exhibited the most potent and selective MAO-B inhibitory effect (hMAO-B IC 50 : 8.9 nM; >10,000-fold selectivity over MAO-A) as a competitive inhibitor. In addition, 12c showed greater MAO-B inhibitory activity and selectivity compared to well-known MAO-B inhibitors such as selegiline, safinamide and sembragiline. In the MPTP-induced mouse model of Parkinson's disease (PD), 12c significantly protected the tyrosine hydroxylase (TH)-immunopositive DAergic neurons and attenuated the PD-associated behavioral deficits. This study suggests characteristic structures as a MAO-B inhibitor that may provide a good insight for the development of therapeutic agents for PD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design and synthesis of a series of serine derivatives as small molecule inhibitors of the SARS coronavirus 3CL protease.

PubMed

Konno, Hiroyuki; Wakabayashi, Masaki; Takanuma, Daiki; Saito, Yota; Akaji, Kenichi

2016-03-15

Synthesis of serine derivatives having the essential functional groups for the inhibitor of SARS 3CL protease and evaluation of their inhibitory activities using SARS 3CL R188I mutant protease are described. The lead compounds, functionalized serine derivatives, were designed based on the tetrapeptide aldehyde and Bai's cinnamoly inhibitor, and additionally performed with simulation on GOLD softwear. Structure activity relationship studies of the candidate compounds were given reasonable inhibitors ent-3 and ent-7k against SARS 3CL R188I mutant protease. These inhibitors showed protease selectivity and no cytotoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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

2010-01-01

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

Synthesis and evaluation of 2-benzylidene-1-tetralone derivatives for monoamine oxidase inhibitory activity.

PubMed

Amakali, Klaudia T; Legoabe, Lesetja Jan; Petzer, Anel; Petzer, Jacobus P

2018-05-01

Chalcone has been identified as a promising lead for the design of monoamine oxidase (MAO) inhibitors. This study attempted to discover potent and selective chalcone-derived MAO inhibitors by synthesising a series consisting of various cyclic chalcone derivatives. The cyclic chalcones were selected based on the possibility that their restricted structures would confer a higher degree of MAO isoform selectivity, and included the following chemical classes: 1-indanone, 1-tetralone, 1-benzosuberone, chromone, thiochromone, 4-chromanone and 4-thiochromanone. The results showed that the cyclic chalcones are in general good potency, and in most instances specific inhibitors of the human MAO-B isoform. Among these compounds, the 4-chromanone derivative was the most potent MAO-B inhibitor with an IC50 value of 0.156 µM. To further investigate the MAO inhibition of cyclic chalcones, a series of twenty-three 2-benzylidene-1-tetralone derivatives were synthesised and evaluated as MAO inhibitors. Most 2-benzylidene-1-tetralones possess good inhibitory activity and specificity for MAO-B with the most potent inhibitor displaying an IC50 value of 0.0064 µM, while the most potent MAO-A inhibitor possessed an IC50 value of 0.754 µM. This study thus shows that certain cyclic chalcones are human MAO-B inhibitors, compounds that could be suitable for the treatment of neurodegenerative disorders such as Parkinson's disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

From a novel HTS hit to potent, selective, and orally bioavailable KDM5 inhibitors.

PubMed

Liang, Jun; Labadie, Sharada; Zhang, Birong; Ortwine, Daniel F; Patel, Snahel; Vinogradova, Maia; Kiefer, James R; Mauer, Till; Gehling, Victor S; Harmange, Jean-Christophe; Cummings, Richard; Lai, Tommy; Liao, Jiangpeng; Zheng, Xiaoping; Liu, Yichin; Gustafson, Amy; Van der Porten, Erica; Mao, Weifeng; Liederer, Bianca M; Deshmukh, Gauri; An, Le; Ran, Yingqing; Classon, Marie; Trojer, Patrick; Dragovich, Peter S; Murray, Lesley

2017-07-01

A high-throughput screening (HTS) of the Genentech/Roche library identified a novel, uncharged scaffold as a KDM5A inhibitor. Lacking insight into the binding mode, initial attempts to improve inhibitor potency failed to improve potency, and synthesis of analogs was further hampered by the presence of a C-C bond between the pyrrolidine and pyridine. Replacing this with a C-N bond significantly simplified synthesis, yielding pyrazole analog 35, of which we obtained a co-crystal structure with KDM5A. Using structure-based design approach, we identified 50 with improved biochemical, cell potency and reduced MW and lower lipophilicity (LogD) compared with the original hit. Furthermore, 50 showed lower clearance than 9 in mice. In combination with its remarkably low plasma protein binding (PPB) in mice (40%), oral dosing of 50 at 5mg/kg resulted in unbound C max ∼2-fold of its cell potency (PC9 H3K4Me3 0.96μM), meeting our criteria for an in vivo tool compound from a new scaffold. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemical probes to potently and selectively inhibit endocannabinoid cellular reuptake.

PubMed

Chicca, Andrea; Nicolussi, Simon; Bartholomäus, Ruben; Blunder, Martina; Aparisi Rey, Alejandro; Petrucci, Vanessa; Reynoso-Moreno, Ines Del Carmen; Viveros-Paredes, Juan Manuel; Dalghi Gens, Marianela; Lutz, Beat; Schiöth, Helgi B; Soeberdt, Michael; Abels, Christoph; Charles, Roch-Philippe; Altmann, Karl-Heinz; Gertsch, Jürg

2017-06-20

The extracellular effects of the endocannabinoids anandamide and 2-arachidonoyl glycerol are terminated by enzymatic hydrolysis after crossing cellular membranes by facilitated diffusion. The lack of potent and selective inhibitors for endocannabinoid transport has prevented the molecular characterization of this process, thus hindering its biochemical investigation and pharmacological exploitation. Here, we report the design, chemical synthesis, and biological profiling of natural product-derived N -substituted 2,4-dodecadienamides as a selective endocannabinoid uptake inhibitor. The highly potent (IC 50 = 10 nM) inhibitor N -(3,4-dimethoxyphenyl)ethyl amide (WOBE437) exerted pronounced cannabinoid receptor-dependent anxiolytic, antiinflammatory, and analgesic effects in mice by increasing endocannabinoid levels. A tailored WOBE437-derived diazirine-containing photoaffinity probe (RX-055) irreversibly blocked membrane transport of both endocannabinoids, providing mechanistic insights into this complex process. Moreover, RX-055 exerted site-specific anxiolytic effects on in situ photoactivation in the brain. This study describes suitable inhibitors to target endocannabinoid membrane trafficking and uncovers an alternative endocannabinoid pharmacology.

Benzoylurea Chitin Synthesis Inhibitors.

PubMed

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

2015-08-12

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

4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic Acid (C75), an Inhibitor of Fatty-acid Synthase, Suppresses the Mitochondrial Fatty Acid Synthesis Pathway and Impairs Mitochondrial Function*

PubMed Central

Chen, Cong; Han, Xiao; Zou, Xuan; Li, Yuan; Yang, Liang; Cao, Ke; Xu, Jie; Long, Jiangang; Liu, Jiankang; Feng, Zhihui

2014-01-01

4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic acid (C75) is a synthetic fatty-acid synthase (FASN) inhibitor with potential therapeutic effects in several cancer models. Human mitochondrial β-ketoacyl-acyl carrier protein synthase (HsmtKAS) is a key enzyme in the newly discovered mitochondrial fatty acid synthesis pathway that can produce the substrate for lipoic acid (LA) synthesis. HsmtKAS shares conserved catalytic domains with FASN, which are responsible for binding to C75. In our study, we explored the possible effect of C75 on HsmtKAS and mitochondrial function. C75 treatment decreased LA content, impaired mitochondrial function, increased reactive oxygen species content, and reduced cell viability. HsmtKAS but not FASN knockdown had an effect that was similar to C75 treatment. In addition, an LA supplement efficiently inhibited C75-induced mitochondrial dysfunction and oxidative stress. Overexpression of HsmtKAS showed cellular protection against low dose C75 addition, whereas there was no protective effect upon high dose C75 addition. In summary, the mitochondrial fatty acid synthesis pathway has a vital role in mitochondrial function. Besides FASN, C75 might also inhibit HsmtKAS, thereby reducing LA production, impairing mitochondrial function, and potentially having toxic effects. LA supplements sufficiently ameliorated the toxicity of C75, showing that a combination of C75 and LA may be a reliable cancer treatment. PMID:24784139

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

PubMed

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

2015-05-30

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

Phosphorylated hydroxyethylamines as novel inhibitors of the bacterial cell wall biosynthesis enzymes MurC to MurF.

PubMed

Sova, Matej; Kovac, Andreja; Turk, Samo; Hrast, Martina; Blanot, Didier; Gobec, Stanislav

2009-12-01

Enzymes involved in the biosynthesis of bacterial peptidoglycan represent important targets for development of new antibacterial drugs. Among them, Mur ligases (MurC to MurF) catalyze the formation of the final cytoplasmic precursor UDP-N-acetylmuramyl-pentapeptide from UDP-N-acetylmuramic acid. We present the design, synthesis and biological evaluation of a series of phosphorylated hydroxyethylamines as new type of small-molecule inhibitors of Mur ligases. We show that the phosphate group attached to the hydroxyl moiety of the hydroxyethylamine core is essential for good inhibitory activity. The IC(50) values of these inhibitors were in the micromolar range, which makes them a promising starting point for the development of multiple inhibitors of Mur ligases as potential antibacterial agents. In addition, 1-(4-methoxyphenylsulfonamido)-3-morpholinopropan-2-yl dihydrogen phosphate 7a was discovered as one of the best inhibitors of MurE described so far.

Design and synthesis of functionalized piperazin-1yl-(E)-stilbenes as inhibitors of 17α-hydroxylase-C17,20-lyase (Cyp17).

PubMed

Blass, Benjamin E; Iyer, Pravin; Abou-Gharbia, Magid; Childers, Wayne E; Gordon, John C; Ramanjulu, Mercy; Morton, George; Arumugam, Premkumar; Boruwa, Joshodeep; Ellingboe, John; Mitra, Sayan; Reddy Nimmareddy, Rajashekar; Paliwal, Shalini; Rajasekhar, Jamallamudi; Shivakumar, Savithiri; Srivastava, Pratima; Tangirala, Raghuram S; Venkataramanaiah, Konda; Bobbala, Ramreddy; Yanamandra, Mahesh; Krishnakanth Reddy, L

2018-07-15

The synthesis of steroid hormones is critical to human physiology and improper regulation of either the synthesis of these key molecules or activation of the associated receptors can lead to disease states. This has led to intense interest in developing compounds capable of modulating the synthesis of steroid hormones. Compounds capable of inhibiting Cyp19 (Aromatase), a key enzyme in the synthesis of estrogens, have been successfully employed as breast cancer therapies, while inhibitors of Cyp17 (17α-hydroxylase-17,20-lyase), a key enzyme in the synthesis of glucocorticoids, mineralocorticoids and steroidal sex hormones, are a key component of prostate cancer therapy. Inhibition of CYP17 has also been suggested as a possible target for the treatment of Cushing Syndrome and Metabolic Syndrome. We have identified two novel series of stilbene based CYP17 inhibitors and demonstrated that exemplary compounds in these series have pharmacokinetic properties consistent with orally delivered drugs. These findings suggest that compounds in these classes may be useful for the treatment of diseases and conditions associated with improper regulation of glucocorticoids synthesis and glucocorticoids receptor activation. Copyright © 2018. Published by Elsevier Ltd.

Milk thistle, a herbal supplement, decreases the activity of CYP3A4 and uridine diphosphoglucuronosyl transferase in human hepatocyte cultures.

PubMed

Venkataramanan, R; Ramachandran, V; Komoroski, B J; Zhang, S; Schiff, P L; Strom, S C

2000-11-01

Milk thistle extract is one of the most commonly used nontraditional therapies, particularly in Germany. Milk thistle is known to contain a number of flavonolignans. We evaluated the effect of silymarin, on the activity of various hepatic drug-metabolizing enzymes in human hepatocyte cultures. Treatment with silymarin (0.1 and 0.25 mM) significantly reduced the activity of CYP3A4 enzyme (by 50 and 100%, respectively) as determined by the formation of 6-beta-hydroxy testosterone and the activity of uridine diphosphoglucuronosyl transferase (UGT1A6/9) (by 65 and 100%, respectively) as measured by the formation of 4-methylumbelliferone glucuronide. Silymarin (0.5 mM) also significantly decreased mitochondrial respiration as determined by MTT reduction in human hepatocytes. These observations point to the potential of silymarin to impair hepatic metabolism of certain coadministered drugs in humans. Indiscriminate use of herbal products may lead to altered pharmacokinetics of certain drugs and may result in increased toxicity of certain drugs.

A PHGDH inhibitor reveals coordination of serine synthesis and 1-carbon unit fate

PubMed Central

Pacold, Michael E.; Brimacombe, Kyle R.; Chan, Sze Ham; Rohde, Jason M.; Lewis, Caroline A.; Swier, Lotteke J.Y.M.; Possemato, Richard; Chen, Walter W.; Sullivan, Lucas B.; Fiske, Brian P.; Cho, Sung Won; Freinkman, Elizaveta; Birsoy, Kıvanç; Abu-Remaileh, Monther; Shaul, Yoav D.; Liu, Chieh Min; Zhou, Minerva; Koh, Min Jung; Chung, Haeyoon; Davidson, Shawn M.; Luengo, Alba; Wang, Amy Q.; Xu, Xin; Yasgar, Adam; Liu, Li; Rai, Ganesha; Westover, Kenneth D.; Vander Heiden, Matthew G.; Shen, Min; Gray, Nathanael S.; Boxer, Matthew B.; Sabatini, David M.

2016-01-01

Serine is a both a proteinogenic amino acid and the source of one-carbon units essential for de novo purine and deoxythymidine synthesis. In the canonical glucose-derived serine synthesis pathway, Homo sapiens phosphoglycerate dehydrogenase (PHGDH) catalyzes the first, rate-limiting step. Genetic loss of PHGDH is toxic towards PHGDH-overexpressing breast cancer cell lines even in the presence of exogenous serine. Here, we use a quantitative high-throughput screen to identify small molecule PHGDH inhibitors. These compounds reduce the production of glucose-derived serine in cells and suppress the growth of PHGDH-dependent cancer cells in culture and in orthotopic xenograft tumors. Surprisingly, PHGDH inhibition reduced the incorporation into nucleotides of one-carbon units from glucose-derived and exogenous serine. We conclude that glycolytic serine synthesis coordinates the use of one-carbon units from endogenous and exogenous serine in nucleotide synthesis, and suggest that one-carbon unit wasting may contribute to the efficacy of PHGDH inhibitors in vitro and in vivo. PMID:27110680

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

PubMed

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

2016-01-01

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

Inhibition of rotavirus replication by downregulation of fatty acid synthesis.

PubMed

Gaunt, Eleanor R; Cheung, Winsome; Richards, James E; Lever, Andrew; Desselberger, Ulrich

2013-06-01

Recently the recruitment of lipid droplets (LDs) to sites of rotavirus (RV) replication was reported. LDs are polymorphic organelles that store triacylglycerols, cholesterol and cholesterol esters. The neutral fats are derived from palmitoyl-CoA, synthesized via the fatty acid biosynthetic pathway. RV-infected cells were treated with chemical inhibitors of the fatty acid biosynthetic pathway, and the effects on viral replication kinetics were assessed. Treatment with compound C75, an inhibitor of the fatty acid synthase enzyme complex (FASN), reduced RV infectivity 3.2-fold (P = 0.07) and modestly reduced viral RNA synthesis (1.2-fold). Acting earlier in the fatty acid synthesis pathway, TOFA [5-(Tetradecyloxy)-2-furoic acid] inhibits the enzyme acetyl-CoA carboxylase 1 (ACC1). TOFA reduced the infectivity of progeny RV 31-fold and viral RNA production 6-fold. The effect of TOFA on RV infectivity and RNA replication was dose-dependent, and infectivity was reduced by administering TOFA up to 4 h post-infection. Co-treatment of RV-infected cells with C75 and TOFA synergistically reduced viral infectivity. Knockdown by siRNA of FASN and ACC1 produced findings similar to those observed by inhibiting these proteins with the chemical compounds. Inhibition of fatty acid synthesis using a range of approaches uniformly had a more marked impact on viral infectivity than on viral RNA yield, inferring a role for LDs in virus assembly and/or egress. Specific inhibitors of fatty acid metabolism may help pinpoint the critical structural and biochemical features of LDs that are essential for RV replication, and facilitate the development of antiviral therapies.

Kinetics of prostaglandin E2 and thromboxane A2 synthesis and suppression of PHA-stimulated peripheral blood mononuclear leucocytes.

PubMed Central

Awara, W; Hillier, K; Jones, D

1986-01-01

The immunomodulatory effects of thromboxane A2 and prostaglandin E2 on peripheral blood mononuclear leucocytes stimulated with PHA in vitro, and the relationship of this to the time-course of their synthesis in culture, were investigated using prostaglandin E2, a thromboxane A2 synthesis inhibitor (UK37248), a thromboxane A2 mimic (U46619) and a thromboxane A2 receptor blocker (EP045). The inhibitory effect of prostaglandin E2 on PHA-induced human peripheral blood mononuclear leucocyte proliferation diminishes if the addition of PGE2 is delayed. If added 4 hr after a maximum concentration of PHA (5 micrograms/ml), the effect of PGE2 was reduced by 60%. If a submaximal concentration of PHA (1 microgram/ml) was used, the effect of PGE2 was not reduced if added 4 hr later but fell by about 60% after 16 hr. UK37248 moderately inhibited PHA-induced activation while substantially inhibiting thromboxane A2 synthesis and simultaneously enhancing PGE2 synthesis. The enhanced accumulation of PGE2 occurs while sensitivity to PGE2 is dropping. U46619, exogenously applied as a thromboxane A2 mimic, inhibited PHA-induced activation at concentrations that did not significantly alter PGE2 synthesis. EP045, which may modulate the effects of endogenous thromboxane A2 by blocking receptors, did not alter PHA-induced activation. We conclude that thromboxane A2 may have a role in inhibiting PHA-induced activation on the basis of the effect of U46619. However, this study highlights difficulties in utilizing prostaglandin and thromboxane receptor and synthesis inhibitors to examine their endogenous role in the modulation of mitogen-induced activation in vitro. If sensitivity to the purported endogenous substance is limited to the early stages of culture and if only low levels are synthesized at this early stage, then blocking drugs would have little effect. PMID:3468061

4-Oxalocrotonate tautomerase, its homologue YwhB, and active vinylpyruvate hydratase: synthesis and evaluation of 2-fluoro substrate analogues.

PubMed

Johnson, William H; Wang, Susan C; Stanley, Thanuja M; Czerwinski, Robert M; Almrud, Jeffrey J; Poelarends, Gerrit J; Murzin, Alexey G; Whitman, Christian P

2004-08-17

A series of 2-fluoro-4-alkene and 2-fluoro-4-alkyne substrate analogues were synthesized and examined as potential inhibitors of three enzymes: 4-oxalocrotonate tautomerase (4-OT) and vinylpyruvate hydratase (VPH) from the catechol meta-fission pathway and a closely related 4-OT homologue found in Bacillus subtilis designated YwhB. All of the compounds were potent competitive inhibitors of 4-OT with the monocarboxylated 2E-fluoro-2,4-pentadienoate and the dicarboxylated 2E-fluoro-2-en-4-ynoate being the most potent. Despite the close mechanistic and structural similarities between 4-OT and YwhB, these compounds were significantly less potent inhibitors of YwhB with K(i) values ranging from 5- to 633-fold lower than those determined for 4-OT. The study of VPH is complicated by the fact that the enzyme is only active as a complex with the metal-dependent 4-oxalocrotonate decarboxylase (4-OD), the enzyme following 4-OT in the catechol meta-fission pathway. A structure-based sequence analysis identified 4-OD as a member of the fumarylacetoacetate hydrolase (FAH) superfamily and implicated Glu-109 and Glu-111 as potential metal-binding ligands. Changing these residues to a glutamine verified their importance for enzymatic activity and enabled the production of soluble E109Q4-OD/VPH or E111Q4-OD/VPH complexes, which retained full hydratase activity but had little decarboxylase activity. Subsequent incubation of the E109Q4-OD/VPH complex with the substrate analogues identified the 2E and 2Z isomers of the monocarboxylated 2-fluoropent-2-en-4-ynoate as competitive inhibitors. The combined results set the stage for crystallographic studies of 4-OT, YwhB, and VPH using these inhibitors as ligands.

Proteasomal degradation of sphingosine kinase 1 and inhibition of dihydroceramide desaturase by the sphingosine kinase inhibitors, SKi or ABC294640, induces growth arrest in androgen-independent LNCaP-AI prostate cancer cells.

PubMed

McNaughton, Melissa; Pitman, Melissa; Pitson, Stuart M; Pyne, Nigel J; Pyne, Susan

2016-03-29

Sphingosine kinases (two isoforms termed SK1 and SK2) catalyse the formation of the bioactive lipid sphingosine 1-phosphate. We demonstrate here that the SK2 inhibitor, ABC294640 (3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide) or the SK1/SK2 inhibitor, SKi (2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole)) induce the proteasomal degradation of SK1a (Mr = 42 kDa) and inhibit DNA synthesis in androgen-independent LNCaP-AI prostate cancer cells. These effects are recapitulated by the dihydroceramide desaturase (Des1) inhibitor, fenretinide. Moreover, SKi or ABC294640 reduce Des1 activity in Jurkat cells and ABC294640 induces the proteasomal degradation of Des1 (Mr = 38 kDa) in LNCaP-AI prostate cancer cells. Furthermore, SKi or ABC294640 or fenretinide increase the expression of the senescence markers, p53 and p21 in LNCaP-AI prostate cancer cells. The siRNA knockdown of SK1 or SK2 failed to increase p53 and p21 expression, but the former did reduce DNA synthesis in LNCaP-AI prostate cancer cells. Moreover, N-acetylcysteine (reactive oxygen species scavenger) blocked the SK inhibitor-induced increase in p21 and p53 expression but had no effect on the proteasomal degradation of SK1a. In addition, siRNA knockdown of Des1 increased p53 expression while a combination of Des1/SK1 siRNA increased the expression of p21. Therefore, Des1 and SK1 participate in regulating LNCaP-AI prostate cancer cell growth and this involves p53/p21-dependent and -independent pathways. Therefore, we propose targeting androgen-independent prostate cancer cells with compounds that affect Des1/SK1 to modulate both de novo and sphingolipid rheostat pathways in order to induce growth arrest.

Design and synthesis of highly potent benzodiazepine gamma-secretase inhibitors: preparation of (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4- hydroxy-N-((3S)-1-methyl-2-oxo-5- phenyl-2,3-dihydro-1H-benzo[e][1,4]-diazepin-3-yl)butyramide by use of an asymmetric Ireland-Claisen rearrangement.

PubMed

Churcher, Ian; Williams, Susie; Kerrad, Sonia; Harrison, Timothy; Castro, José L; Shearman, Mark S; Lewis, Huw D; Clarke, Earl E; Wrigley, Jonathan D J; Beher, Dirk; Tang, Yui S; Liu, Wensheng

2003-06-05

Novel benzodiazepine-containing gamma-secretase inhibitors for potential use in Alzheimer's disease have been designed that incorporate a substituted hydrocinnamide C-3 side chain. A syn combination of alpha-alkyl or aryl and beta-hydroxy or hydroxymethyl substituents was shown to give highly potent compounds. In particular, (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4-hydroxy-N-((3S)-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)butyramide (34) demonstrated excellent in vitro potency (IC(50) = 0.06 nM). 34 could also be selectively methylated to give [(3)H]-28, which is of use in radioligand binding assays.

Synthesis, biological evaluation, and molecular docking of Ugi products containing a zinc-chelating moiety as novel inhibitors of histone deacetylases.

PubMed

Grolla, Ambra A; Podestà, Valeria; Chini, Maria Giovanna; Di Micco, Simone; Vallario, Antonella; Genazzani, Armando A; Canonico, Pier Luigi; Bifulco, Giuseppe; Tron, Gian Cesare; Sorba, Giovanni; Pirali, Tracey

2009-05-14

HDAC inhibitors show great promise for the treatment of cancer. As part of a broader effort to explore the SAR of HDAC inhibitors, synthesis, biological evaluation, and molecular docking of novel Ugi products containing a zinc-chelating moiety are presented. One compound shows improved inhibitory potencies compared to SAHA, demonstrating that hindered lipophilic residues grafted on the peptide scaffold of the alpha-aminoacylamides can be favorable in the interaction with the enzyme.

Design, synthesis and biological evaluation of novel xanthine oxidase inhibitors bearing a 2-arylbenzo[b]furan scaffold.

PubMed

Tang, Hong-Jin; Li, Wei; Zhou, Mei; Peng, Li-Ying; Wang, Jin-Xin; Li, Jia-Huang; Chen, Jun

2018-05-10

Xanthine oxidase, which catalyzes the oxidative reaction of hypoxanthine and xanthine into uric acid, is a key enzyme to the pathogenesis of hyperuricemia and gout. In this study, for the purpose of discovering novel xanthine oxidase (XO) inhibitors, a series of 2-arylbenzo[b]furan derivatives (3a-3d, 4a-4o and 6a-6d) were designed and synthesized. All these compounds were evaluated their xanthine oxidase inhibitory and antioxidant activities by using in vitro enzymatic assay and cellular model. The results showed that a majority of the designed compounds exhibited potent xanthine oxidase inhibitory effects and antioxidant activities, and compound 4a emerged as the most potent xanthine oxidase inhibitor (IC 50  = 4.45 μM). Steady-state kinetic measurements of the inhibitor 4a with the bovine milk xanthine oxidase indicated a mixed type inhibition with 3.52 μM K i and 13.14 μM K is , respectively. The structure-activity relationship analyses have also been presented. Compound 4a exhibited the potent hypouricemic effect in the potassium oxonate-induced hyperuricemic mice model. A molecular docking study of compound 4a was performed to gain an insight into its binding mode with xanthine oxidase. These results highlight the identification of a new class of xanthine oxidase inhibitors that have potential to be more efficacious in treatment of gout. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Autolytic enzymes are responsible for increased melanization of carbon stressed Aspergillus nidulans cultures.

PubMed

Szilágyi, Melinda; Anton, Fruzsina; Pócsi, István; Emri, Tamás

2018-05-01

Melanization of carbon stressed Aspergillus nidulans cultures were studied. Melanin production showed strong positive correlation with the activity of the secreted chitinase and ß-1,3-glucanase. Deletion of either chiB encoding an autolytic endochitinase or engA encoding an autolytic ß-1,3-endoglucanase, or both, almost completely prevented melanization of carbon stressed cultures. In contrast, addition of Trichoderma lyticase to cultures induced melanin production. Synthetic melanin could efficiently inhibit the purified ChiB chitinase activity. It could also efficiently decrease the intensity of hyphal fragmentation and pellet disorganization in Trichoderma lyticase treated cultures. Glyphosate, an inhibitor of L-3,4-dihydroxyphenylalanine-type melanin synthesis, could prevent melanization of carbon-starved cultures and enhanced pellet disorganization, while pyroquilon, a 1,8-dihydroxynaphthalene-type melanin synthesis inhibitor, enhanced melanization, and prevented pellet disorganization. We concluded that cell wall stress induced by autolytic cell wall hydrolases was responsible for melanization of carbon-starved cultures. The produced melanin can shield the living cells but may not inhibit the degradation and reutilization of cell wall materials of dead hyphae. Controlling the activity of autolytic hydrolase production can be an efficient approach to prevent unwanted melanization in the fermentation industry, while applying melanin synthesis inhibitors can decrease the resistance of pathogenic fungi against the chitinases produced by the host organism. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed

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

2015-03-04

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

Synthesis, biological evaluation and molecular modelling of diversely functionalized heterocyclic derivatives as inhibitors of acetylcholinesterase/butyrylcholinesterase and modulators of Ca2+ channels and nicotinic receptors.

PubMed

Marco, José L; de los Ríos, Cristóbal; García, Antonio G; Villarroya, Mercedes; Carreiras, M Carmo; Martins, Carla; Eleutério, Ana; Morreale, Antonio; Orozco, M; Luque, F Javier

2004-05-01

The synthesis and the biological activity of compounds 5-40 as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), as well as modulators of voltage-dependent Ca(2+) channels and nicotinic receptors, are described. These molecules are tacrine analogues, which have been prepared from polyfunctionalized 6-amino-5-cyano-4H-pyrans, 6-amino-5-cyano-pyridines and 5-amino-2-aryl-3-cyano-1,3-oxazoles via Friedländer reaction with selected cycloalkanones. These compounds are moderate acetylcholinesterase and butyrylcholinesterase inhibitors, the BuChE/AChE selectivity of the most active molecules ranges from 10.0 (compound 29) to 76.9 (compound 16). Interestingly, the 'oxazolo-tacrine' derivatives are devoid of any activity. All compounds showed an important inhibitory effect on the nicotinic acetylcholine receptor. Most of them also blocked L-type Ca(2+) channels, and three of them, 64, 19 and 67, the non-L type of Ca(2+) channels. Molecular modelling studies suggest that these compounds might bind at the peripheral binding site of AChE, which opens the possibility to design inhibitors able to bind at both, the catalytic and peripheral binding sites of the enzyme.

Design, Synthesis, and Protein Crystallography of Biaryltriazoles as Potent Tautomerase Inhibitors of Macrophage Migration Inhibitory Factor

DOE PAGES

Dziedzic, Pawel; Cisneros, José A.; Robertson, Michael J.; ...

2015-02-20

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

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

PubMed Central

Cardozo, Suzana Vanessa S.; Carvalho, Vinicius de Frias; Romeiro, Nelilma Correia; Silva, Patrícia Machado Rodrigues e; Martins, Marco Aurélio; Barreiro, Eliezer J.; Lima, Lídia Moreira

2016-01-01

Prior investigations showed that increased levels of cyclic AMP down-regulate lung inflammatory changes, stimulating the interest in phosphodiesterase (PDE)4 as therapeutic target. Here, we described the synthesis, pharmacological profile and docking properties of a novel sulfonamide series (5 and 6a-k) designed as PDE4 inhibitors. Compounds were screened for their selectivity against the four isoforms of human PDE4 using an IMAP fluorescence polarized protocol. The effect on allergen- or LPS-induced lung inflammation and airway hyper-reactivity (AHR) was studied in A/J mice, while the xylazine/ketamine-induced anesthesia test was employed as a behavioral correlate of emesis in rodents. As compared to rolipram, the most promising screened compound, 6a (LASSBio-448) presented a better inhibitory index concerning PDE4D/PDE4A or PDE4D/PDE4B. Accordingly, docking analyses of the putative interactions of LASSBio-448 revealed similar poses in the active site of PDE4A and PDE4C, but slight unlike orientations in PDE4B and PDE4D. LASSBio-448 (100 mg/kg, oral), 1 h before provocation, inhibited allergen-induced eosinophil accumulation in BAL fluid and lung tissue samples. Under an interventional approach, LASSBio-448 reversed ongoing lung eosinophilic infiltration, mucus exacerbation, peribronchiolar fibrosis and AHR by allergen provocation, in a mechanism clearly associated with blockade of pro-inflammatory mediators such as IL-4, IL-5, IL-13 and eotaxin-2. LASSBio-448 (2.5 and 10 mg/kg) also prevented inflammation and AHR induced by LPS. Finally, the sulfonamide derivative was shown to be less pro-emetic than rolipram and cilomilast in the assay employed. These findings suggest that LASSBio-448 is a new PDE4 inhibitor with marked potential to prevent and reverse pivotal pathological features of diseases characterized by lung inflammation, such as asthma. PMID:27695125

Catecholic amides as potential selective phosphodiesterase 4D inhibitors: Design, synthesis, pharmacological evaluation and structure-activity relationships.

PubMed

Zhou, Zhong-Zhen; Ge, Bing-Chen; Chen, Yu-Fang; Shi, Xiu-Dong; Yang, Xue-Mei; Xu, Jiang-Ping

2015-11-15

In this study, a series of catechol-based amides (8a-n) with different amide linkers linking the catecholic moiety to the terminal phenyl ring was designed and synthesized as potent phosphodiesterase (PDE) 4D inhibitors. The inhibitory activities of these compounds were evaluated against the core catalytic domains of human PDE4 (PDE4CAT), full-length PDE4B1 and PDE4D7 enzymes, and other PDE family members. The results indicated the majority of compounds 8a-n displayed moderate to good inhibitory activities against PDE4CAT. Among these compounds, compound 8 j with a short amide linker (-CONHCH2-) displayed comparable PDE4CAT inhibitory activity (IC50=410 nM) with rolipram. More interestingly, compound 8 g, a potent and selective PDE4D inhibitor (IC50=94 nM), exhibited a 10-fold selectivity over the PDE4B subtypes and an over 1000-fold selectivity against other PDE family members. Docking simulations suggested that 8 g forms three extra H-bonds with the N-H of residue Asn487 and two water molecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and biological evaluation of 2-substituted-5-(4-nitrophenylsulfonamido)benzoxazoles as human GST P1-1 inhibitors, and description of the binding site features.

PubMed

Ertan-Bolelli, Tuğba; Musdal, Yaman; Bolelli, Kayhan; Yilmaz, Serap; Aksoy, Yasemin; Yildiz, Ilkay; Aki-Yalcin, Esin; Yalcin, Ismail

2014-05-01

Glutathione-S-transferases (GSTs) are enzymes involved in cellular detoxification by catalyzing the nucleophilic attack of glutathione (GSH) on the electrophilic center of numerous of toxic compounds and xenobiotics, including chemotherapeutic drugs. Human GST P1-1, which is known as the most prevalent isoform of the mammalian cytosolic GSTs, is overexpressed in many cancers and contributes to multidrug resistance by directly conjugating to chemotherapeutics. It is suggested that this resistance is related to the high expression of GST P1-1 in cancers, thereby contributing to resistance to chemotherapy. In addition, GSTs exhibit sulfonamidase activity, thereby catalyzing the GSH-mediated hydrolysis of sulfonamide bonds. Such reactions are of interest as potential tumor-directed prodrug activation strategies. Herein we report the design and synthesis of some novel sulfonamide-containing benzoxazoles, which are able to inhibit human GST P1-1. Among the tested compounds, 2-(4-chlorobenzyl)-5-(4-nitrophenylsulfonamido)benzoxazole (5 f) was found as the most active hGST P1-1 inhibitor, with an IC50 value of 10.2 μM, showing potency similar to that of the reference drug ethacrynic acid. Molecular docking studies performed with CDocker revealed that the newly synthesized 2-substituted-5-(4-nitrophenylsulfonamido)benzoxazoles act as catalytic inhibitors of hGST P1-1 by binding to the H-site and generating conjugates with GSH to form S-(4-nitrophenyl)GSH (GS-BN complex) via nucleophilic aromatic substitution reaction. The 4-nitrobenzenesulfonamido moiety at position 5 of the benzoxazole ring is essential for binding to the H-site and for the formation of the GST-mediated GSH conjugate. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of 4-(3'-[125I]iodoanilino)-6,7-dialkoxyquinazolines:radiolabeled epidermal growth factor receptor tyrosine kinaseinhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, John K.; Negash, Kitaw; Hanrahan, Stephen M.

1999-10-25

The preparation of two radioiodinated analogs of theepidermal growth factor receptor tyrosine kinase (EGFrTK) inhibitorPD153035(4-(3'-bromoanilino)-6,7-dimethoxyquinazoline) are reportedherein. The two analogs,4-(3'-[125I]iodoanilino)-6,7-dimethoxyquinazoline and4-(3'-[125I]iodoanilino)-6,7-diethoxyquinazoline, were synthesizedviaiododestannylation of the corresponding4-(3'-trimethylstannylanilino)-6,7-dialkoxyquinazolines to form thedesired I-125 labeled products in good yield and high radiochemicalpurity (>99 percent).

Evaluation of EML4-ALK Fusion Proteins in Non-Small Cell Lung Cancer Using Small Molecule Inhibitors12

PubMed Central

Li, Yongjun; Ye, Xiaofen; Liu, Jinfeng; Zha, Jiping; Pei, Lin

2011-01-01

The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene resulting from an inversion within chromosome 2p occurs in approximately 5% of non-small cell lung cancer and is mutually exclusive with Ras and EGFR mutations. In this study, we have used a potent and selective ALK small molecule inhibitor, NPV-TAE684, to assess the oncogenic role of EML4-ALK in non-small cell lung cancer (NSCLC). We show here that TAE684 inhibits proliferation and induces cell cycle arrest, apoptosis, and tumor regression in two NSCLC models that harbor EML4-ALK fusions. TAE684 inhibits EML4-ALK activation and its downstream signaling including ERK, AKT, and STAT3. We used microarray analysis to carry out targeted pathway studies of gene expression changes in H2228 NSCLC xenograft model after TAE684 treatment and identified a gene signature of EML4-ALK inhibition. The gene signature represents 1210 known human genes, and the top biologic processes represented by these genes are cell cycle, DNA synthesis, cell proliferation, and cell death. We also compared the effect of TAE684 with PF2341066, a c-Met and ALK small molecule inhibitor currently in clinical trial in cancers harboring ALK fusions, and demonstrated that TAE684 is a much more potent inhibitor of EML4-ALK. Our data demonstrate that EML4-ALK plays an important role in the pathogenesis of a subset of NSCLC and provides insight into the mechanism of EML4-ALK inhibition by a small molecule inhibitor. PMID:21245935

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

PubMed

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

2018-01-15

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

Discovery and gram-scale synthesis of BMS-593214, a potent, selective FVIIa inhibitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Priestley, E. Scott; De Lucca, Indawati; Zhou, Jinglan

A 6-amidinotetrahydroquinoline screening hit was driven to a structurally novel, potent, and selective FVIIa inhibitor through a combination of library synthesis and rational design. An efficient gram-scale synthesis of the active enantiomer BMS-593214 was developed, which required significant optimization of the key Povarov annulation. Importantly, BMS-593214 showed antithrombotic efficacy in a rabbit arterial thrombosis model. A crystal structure of BMS-593214 bound to FVIIa highlights key contacts with Asp 189, Lys 192, and the S2 pocket.

Cost effectiveness of dipeptidyl peptidase-4 inhibitors for type 2 diabetes.

PubMed

Geng, Jinsong; Yu, Hao; Mao, Yiwei; Zhang, Peng; Chen, Yingyao

2015-06-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of antidiabetic drugs used for treating type 2 diabetes mellitus. While many studies have reported on the cost-effectiveness of DPP-4 inhibitors for treating type 2 diabetes, a systematic review of economic evaluations of DPP-4 inhibitors is currently lacking. The aim of this systematic review was to assess the cost effectiveness of DPP-4 inhibitors for patients with type 2 diabetes. MEDLINE, EMBASE, National Health Service Economic Evaluation Database (NHS EED), Web of Science, EconLit databases, and the Cochrane Library were searched in November 2013. Studies assessing the cost effectiveness of DPP-4 inhibitors for type 2 diabetes were eligible for analysis. DPP-4 inhibitor monotherapy or combinations with other antidiabetic agents were included in the review. The DPP-4 inhibitors were all marketed drugs. Two reviewers independently reviewed titles, abstracts, and articles sequentially to select studies for data abstraction based on the inclusion and exclusion criteria. Disagreements were resolved by consensus. The quality of included studies was assessed according to the 24-item checklist of the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement. The costs reported by the included studies were converted to US dollars via purchasing power parities (PPP) in the year 2013 using the CCEMG-EPPI-Center Cost Converter. A total of 11 published studies were selected for inclusion; all were cost-utility analyses. Nine studies were conducted from a payer perspective and one used a societal perspective; however, the perspective of the other study was unclear. Four studies were of good quality, six were of moderate quality, and one was of low quality. Of the seven studies comparing DPP-4 inhibitors plus metformin with sulfonylureas plus metformin, six concluded that DPP-4 inhibitors were cost effective in patients with type 2 diabetes who were no longer adequately controlled by metformin monotherapy. Five studies compared DPP-4 inhibitors with thiazolidinediones, and whether DPP-4 inhibitors were cost effective was uncertain. Only two economic evaluations provided data to compare DPP-4 inhibitors versus insulin, and the results favored the use of DPP-4 inhibitors as second-line therapy. Synthesis of the data was impossible because of heterogeneity in the methodology and data sources of the economic evaluations, and the inclusion criteria excluded conference abstracts. It was difficult to find reliable weightings for each of the items of the CHEERS checklist, and the ratings were dichotomous. This study provides the first systematic evaluation of DPP-4 inhibitors for patients with type 2 diabetes. It found that, in patients with type 2 diabetes who do not achieve glycemic targets with antidiabetic monotherapy, DPP-4 inhibitors as add-on treatment may represent a cost-effective option compared with sulfonylureas and insulin. However, high-quality cost-effectiveness analyses that utilize long-term follow-up data and have no conflicts of interest are still needed.

Lactate metabolism and cytosolic NADH reducing equivalents in ovine adipocytes.

PubMed

Yang, Y T; White, L S; Muir, L A

1982-01-01

1. Isolated ovine adipocytes, unlike rat adipose tissue, could utilize lactate at a high rate. 2. When the rate of fatty acid synthesis was attenuated with 5-(tetradecyloxy)-2-furoic acid, a fatty acid synthesis inhibitor, there was a good positive correlation between the rates of lactate oxidation to CO2 and lactate incorporation into fatty acids. 3. Addition of 2,4-dinitrophenol enhanced lactate oxidation to CO2 independent of fatty acid synthesis. Under this condition, estimated cytosolic NADH formation from lactate dehydrogenation exceeded the need of NADH for cytosolic oxaloacetate reduction and for glyceride glycerol formation. 4. Mitochondria isolated from ovine adipocytes oxidized added NADH rapidly in a reconstituted alpha-glycerophosphate shuttle system. 5. It is possible that the ability of ovine adipocytes to utilize lactate may be related to the active alpha-glycerophosphate shuttle for cytosolic NADH reoxidation.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Arun K.; Sean Fyvie, W.; Brindisi, Margherita

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

Bicarbonate dependency of betaine synthesis in cultured LLC-PK1 cells.

PubMed

Moeckel, G W; Lien, Y H

1994-03-01

Betaine, one of the major renal organic osmolytes, is synthesized from choline by choline dehydrogenase (EC 1.1.99.1) and betaine-aldehyde dehydrogenase (EC 1.2.1.8) in the kidney. A recent in vitro study has shown that betaine synthesis by renal cortical homogenate is dependent on millimolar amounts of bicarbonate. The present study was aimed to investigate the bicarbonate dependency of betaine formation in cultured LLC-PK1 cells. The data show that betaine formation increases in accordance with a rise in extracellular bicarbonate levels. The measured quantities of [14C]betaine synthesis ranged from 13.4 +/- 1.5 (4.6 mM HCO3-) to 38.0 +/- 1.4 pmol.micrograms protein-1.h-1 (24 mM HCO3-). The carbonic anhydrase inhibitor acetazolamide, added to the incubation medium to block bicarbonate transport, reduced betaine synthesis from choline by 41-49%. We conclude that betaine synthesis in LLC-PK1 cells is dependent on extracellular bicarbonate levels and is reduced by the inhibition of carbonic anhydrase. Because betaine accumulates in renal medulla during antidiuresis, our observations suggest a possible link between acid-base homeostasis and concentration mechanisms in the kidney.

Synthesis and evaluation of benzo[b]thiophene derivatives as inhibitors of alkaline phosphatases.

PubMed

Li, Lina; Chang, Lei; Pellet-Rostaing, Stéphane; Liger, François; Lemaire, Marc; Buchet, René; Wu, Yuqing

2009-10-15

Presence of basic calcium phosphate in knee joints of osteoarthritis patients could be prevented by inhibiting tissue non-specific alkaline phosphatase (TNAP) activity. Levamisole or the L stereoisomer of tetramisole (a known TNAP inhibitor) has been used as a treatment for curing rheumatoid arthritis but its therapeutical use is limited due to side effects. We report the synthesis and the TNAP inhibition property of benzo[b]thiophene derivatives, among which benzothiopheno-tetramisole and benzothiopheno-2,3-dehydrotetramisole, which could be involved in a drug therapy for osteoarthritis. Two water soluble racemic benzothiopheno-tetramisole and -2,3-dehydrotetramisole with apparent inhibition constants K(i)=85+/-6 microM and 135+/-3 microM (n=3) comparable to that of enantiomeric levamisole 93+/-4 microM were found. Several novel derivatives showed more pronounced inhibition properties towards intestinal alkaline phosphatase than TNAP.

Proquazone: a treatment for lymphocytic infiltration of the skin. Comparative study with 2 other nonsteroid anti-inflammatory drugs.

PubMed

Johansson, E A

1987-01-01

15 patients with lymphocytic infiltration of the skin (LIS) were treated with the nonsteroid anti-inflammatory (NSAI) drug proquazone [1-isopropyl-4-phenyl-7-methyl-2(IH)]. In contrast to other NSAI drugs proquazone is a nonacidic compound which is known to be a potent prostaglandin synthesis inhibitor. Of the 15 patients 8 were healed completely with proquazone; in half of these patients lesions recurred but healed with reintroduction of the drug. Two patients remained symptom-free with a small maintenance dose. Two patients showed a partial remission. The treatment was discontinued in 3 patients, in 2 of them because of side effects and in 1 because of lack of response. Two other NSAI drugs, both known to be potent prostaglandin synthesis inhibitors, namely indomethacin and ibuprofen, were tried, however without effect. The present study indicates that proquazone should be considered in the treatment of LIS.

Design, synthesis, and evaluation of inhibitors of trypanosomal and leishmanial dihydrofolate reductase.

PubMed

Chowdhury, S F; Villamor, V B; Guerrero, R H; Leal, I; Brun, R; Croft, S L; Goodman, J M; Maes, L; Ruiz-Perez, L M; Pacanowska, D G; Gilbert, I H

1999-10-21

This paper concerns the design, synthesis, and evaluation of inhibitors of leishmanial and trypanosomal dihydrofolate reductase. Initially study was made of the structures of the leishmanial and human enzyme active sites to see if there were significant differences which could be exploited for selective drug design. Then a series of compounds were synthesized based on 5-benzyl-2, 4-diaminopyrimidines. These compounds were assayed against the protozoan and human enzymes and showed selectivity for the protozoan enzymes. The structural data was then used to rationalize the enzyme assay data. Compounds were also tested against the clinically relevant forms of the intact parasite. Activity was seen against the trypanosomes for a number of compounds. The compounds were in general less active against Leishmania. This latter result may be due to uptake problems. Two of the compounds also showed some in vivo activity in a model of African trypanosomiasis.

Synthesis, characterization and corrosion inhibition properties of benzamide-2-chloro-4-nitrobenzoic acid and anthranilic acid-2-chloro-4-nitrobenzoic acid for mild steel corrosion in acidic medium

NASA Astrophysics Data System (ADS)

Pandey, Archana; Verma, Chandrabhan; Singh, B.; Ebenso, Eno E.

2018-03-01

The present study deals with the synthesis of two new compounds namely, benzamide - 2-chloro-4-nitrobenzoic acid (BENCNBA) and anthranilic acid-2-chloro-4-nitrobenzoic acid (AACNBA) using solid phase reactions. The phase diagram studies revealed that formation of the investigated compounds occurs in 1:1 molar ratio. The synthesized compounds were characterized using several spectral techniques such as FT-IR, 1H and 13C NMR, UV-Vis, powder X-ray diffraction (PXRD). Single crystal XRD (SCXRD) study showed that both BENCNBA and AACNBA compounds crystallize in triclinic crystal system with P-1 space group. Further, the presence of intermolecular hydrogen bonding between the constituent components was also supported by single crystal X-ray diffraction (SCXRD) method. Heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions have also been computed using the enthalpy of fusion values derived from differential scanning calorimeter (DSC) study. The inhibition effect of BENCNBA and AACNBA on the mild steel corrosion in hydrochloric acid solution was tested using electrochemical methods. Electrochemical impedance spectroscopy (EIS) study revealed that both BENCNBA and AACNBA behaved as interface corrosion inhibitors and showed maximum inhibition efficiencies of 95.71% and 96.42%, respectively at 400 ppm (1.23 × 10-3 M) concentration. Potentiodynamic polarization (PDP) measurements suggested that BENCNBA and AACNBA acted as mixed type corrosion inhibitors. EIS and PDP results showed that BENCNBA and AACNBA act as efficient corrosion inhibitors for mild steel and their inhibition efficiencies enhances on increasing their concentrations.

Synthesis, characterization and biological evaluation of novel chalcone sulfonamide hybrids as potent intestinal alkaline phosphatase inhibitors.

PubMed

Ejaz, Syeda Abida; Saeed, Aamer; Siddique, Muhammad Nasir; Nisa, Zaib Un; Khan, Samiullah; Lecka, Joanna; Sévigny, Jean; Iqbal, Jamshed

2017-02-01

Alkaline phosphatase (AP) and ecto-5'-nucleotidase (e5'NT) belong to same family that hydrolyze the extracellular nucleotides and ensure the bioavailability of nucleotides and nucleosides at purinergic receptors. During pathophysiological conditions, the over expression of AP and e5'NT lead to an increased production of adenosine that enhance tumor proliferation, invasiveness, neoangiogenesis and disrupts the body antitumor response. As both enzymes are abundantly expressed in above mentioned conditions, therefore it is of great interest to synthesize and develop potent inhibitors of these enzymes that augment the antitumor therapy. Herein we reported the synthesis and biological activity of a new series of chalcone-sulfonamide hybrids (4a-j). These derivatives were then evaluated for their inhibitory potential against two members of ecto-nucleotidase family, e5'NT (human and rat) and APs isozyme (intestinal and tissue nonspecific). Only six derivatives were found to inhibit both human and rat e5'NT enzymes. Compounds 4e and 4d showed maximum inhibition of human and rat e5'NT with an IC 50 ±SEM=0.26±0.01 and 0.33±0.004μM, respectively. Moreover, on APs, these derivatives were identified as the selective inhibitors of calf intestinal AP (c-IAP). The derivative 4a exhibited maximum inhibition of c-IAP with an IC 50 ±SEM=0.12±0.02μM. In conclusion, these chalcone-sulfonamide hybrids exhibited dual inhibition of both family of isozymes but was more selective towards c-IAP enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis, biological assessment, and molecular modeling of racemic 7-aryl-9,10,11,12-tetrahydro-7H-benzo[7,8]chromeno[2,3-b]quinolin-8-amines as potential drugs for the treatment of Alzheimer's disease.

PubMed

Maalej, Emna; Chabchoub, Fakher; Oset-Gasque, María Jesús; Esquivias-Pérez, Mario; González, María P; Monjas, Leticia; Pérez, Concepción; de los Ríos, Cristóbal; Rodríguez-Franco, María Isabel; Iriepa, Isabel; Moraleda, Ignacio; Chioua, Mourad; Romero, Alejandro; Marco-Contelles, José; Samadi, Abdelouahid

2012-08-01

The synthesis, pharmacological analysis and molecular modeling of the readily available racemic tacrine analogs 21-30, bearing the 7-aryl-9,10,11,12-tetrahydro-7H-benzo[7,8]chromeno[2,3-b]quinolin-8-amine heterocyclic ring system (II), prepared by Friedländer reaction of 2-amino-4-aryl-4H-benzo[h]chromene-3-carbonitriles (11-20) with cyclohexanone, are described in this paper. Molecules 21-30 are potent and selective inhibitors of hAChE, in the low micromolar range, one of the most potent inhibitors, 4-(8-amino-9,10,11,12-tetrahydro-7H-benzo[7,8]chromeno[2,3-b]quinolin-7-yl)-2-methoxyphenol (25), showing a IC(50) (hAChE) = 0.33 ± 0.04 μM. Kinetic studies of compound 25 proved that this compound is a mixed type inhibitor for EeAChE (K(i) = 81 nM). Accordingly, molecular modeling of inhibitor 25 showed that both enantiomers have two major predicted binding modes at the active and at the peripheral anionic sites of AChE. Inhibitor 25 has an excellent antioxidant profile as determined in the ORAC experiment (1.47 ± 0.10 Trolox equiv). Inhibitors 26-28 and 30 are permeable to BBB as determined in the PAMPA assay. Compared to tacrine, selected compounds 26-28 and 30 showed less hepatic toxicity in HepG2 cells. Moreover, cell viability-related studies in cortical neurons in primary cultures show that compounds 26-28 and 30 (0.1-50 μM) have significant neuroprotective effects against mitochondrial chain blockers-induced cell death, and, unlike tacrine, are not neurotoxic at concentrations lower than 50 μM. It is worth highlighting that compound 27 has the best neuroprotective properties out of all assayed compounds and shows no neurotoxicity. To sum up, these tacrine analogs can be considered as attractive multipotent therapeutic molecules on pharmacological receptors playing key roles in the progress of Alzheimer's disease. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Discovery of Quinoline-Derived Trifluoromethyl Alcohols, Determination of Their in vivo Toxicity and Anticancer Activity in a Zebrafish Embryo Model.

PubMed

Sittaramane, Vinoth; Padgett, Jihan; Salter, Philip; Williams, Ashley; Luke, Shauntelle; McCall, Rebecca; Arambula, Jonathan F; Graves, Vincent B; Blocker, Mark; Van Leuven, David; Bowe, Keturah; Heimberger, Julia; Cade, Hannah C; Immaneni, Supriya; Shaikh, Abid

2015-11-01

In this study the rational design, synthesis, and anticancer activity of quinoline-derived trifluoromethyl alcohols were evaluated. Members of this novel class of trifluoromethyl alcohols were identified as potent growth inhibitors in a zebrafish embryo model. Synthesis of these compounds was carried out with an sp(3) -C-H functionalization strategy of methyl quinolines with trifluoromethyl ketones. A zebrafish embryo model was also used to explore the toxicity of ethyl 4,4,4-trifluoro-3-hydroxy-3-(quinolin-2-ylmethyl)butanoate (1), 2-benzyl-1,1,1-trifluoro-3-(quinolin-2-yl)propan-2-ol (2), and trifluoro-3-(isoquinolin-1-yl)-2-(thiophen-2-yl)propan-2-ol (3). Compounds 2 and 3 were found to be more toxic than compound 1; apoptotic staining assays indicated that compound 3 causes increased cell death. In vitro cell proliferation assays showed that compound 2, with an LC50 value of 14.14 μm, has more potent anticancer activity than cisplatin. This novel class of inhibitors provides a new direction in the discovery of effective anticancer agents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed

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

2010-03-05

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

Synthesis and Evaluation of Eight- and Four-membered Iminosugar Analogues as Inhibitors of Testicular Ceramide-specific Glucosyltransferase, Testicular β-Glucosidase 2, and other Glycosidases

PubMed Central

Lee, Jae Chul; Francis, Subhashree; Dutta, Dinah; Gupta, Vijayalaxmi; Yang, Yan; Zhu, Jin-Yi; Tash, Joseph S.; Schönbrunn, Ernst

2012-01-01

Eight- and four-membered analogues of N-butyldeoxynojirimycin (NB-DNJ), a reversible male contraceptive in mice, were prepared and tested. A chiral pool approach was used for the synthesis of the target compounds. Key steps for the synthesis of the eight-membered analogues involve: ringclosing metathesis and Sharpless asymmetric dihydroxylation, and for the four-membered analogues: Sharpless epoxidation, epoxide ring opening (azide), and Mitsunobu reaction to form the four-membered ring. (3S,4R,5S,6R,7R)-1-Nonylazocane-3,4,5,6,7-pentaol (6), was moderately active against rat-derived ceramide-specific glucosyltransferase and four of the other eight-membered analogues were weakly active against rat-derived β-glucosidase 2. Among the four-membered analogues, ((2R,3s,4S)-3-hydroxy-1-nonylazetidine-2,4-diyl)dimethanol (25), displayed selective inhibitory activity against mouse-derived ceramide-specific glucosyltransferase and was about half as potent as NB-DNJ against the rat-derived enzyme. ((2S,4S)-3-Hydroxy-1-nonyl-azetidine-2,4-diyl)dimethanol (27) was found to be a selective inhibitor of β-glucosidase 2, with potency similar to NB-DNJ. Additional glycosidase assays were performed to identify potential other therapeutic applications. The eight-membered iminosugars exhibited specificity for almond-derived β-glucosidase and the 1-nonylazetidine 25 inhibited α-glucosidase (Saccharomyces cerevisiae) with an IC50 of 600 nM and β-glucosidase (almond) with an IC50 of 20 µM. Only N-nonyl derivatives were active, emphasizing the importance of a long lipophilic side chain for inhibitory activity of the analogues studied. PMID:22432895

Pyrimidin-2(1H)-ones based inhibitors of Mycobacterium tuberculosis orotate phosphoribosyltransferase.

PubMed

Breda, Ardala; Machado, Pablo; Rosado, Leonardo Astolfi; Souto, André Arigony; Santos, Diógenes Santiago; Basso, Luiz Augusto

2012-08-01

Tuberculosis (TB) is an ancient human chronic infectious disease caused mainly by Mycobacterium tuberculosis. The emergence of strains resistant to first and second line anti-TB drugs, associated with the increasing number of TB cases among HIV positive subjects, and the large number of individuals infected with latent bacilli have urged the development of new strategies to treat TB. Enzymes of nucleotide metabolism pathways provide promising molecular targets for the development of drugs, aiming at both active and latent TB. The orotate phosphoribosyltransferase (OPRT) enzyme catalyzes the synthesis of orotidine 5'-monophosphate from 5'-phospho-α-d-ribose 1'-diphosphate and orotic acid, in the de novo pyrimidine synthesis pathway. Based on the kinetic mechanism and molecular properties, here we describe the design, selection and synthesis of substrate analogs with inhibitory activity of M. tuberculosis OPRT (MtOPRT) enzyme. Steady-state kinetic measurements were employed to determine the mode of inhibition of commercially available and chemically derived compounds. The 6-Hydroxy-2-oxo-1,2-dihydropyridine-4-carboxylic acid (6) chemical compound and its derivative, 3-Benzylidene-2,6-dioxo-1,2,3,6-tetrahydropyridine-4-carboxylic acid (13), showed enzyme inhibition constants in the submicromolar range. Isothermal titration calorimetry data indicated that binding of both compounds to MtOPRT have negative enthalpy and favorable Gibbs free energy probably due to their high complementarity to the enzyme's binding pocket. Improvement of compound 13 hydrophobic character by addition of an aromatic ring substituent resulted in entropic optimization, reflected on a thermodynamic discrimination profile characteristic of high affinity ligands. These inhibitors represent lead compounds for further development of MtOPRT inhibitors with increased potency, which may be tested as anti-TB agents. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Antimicrobial Treatment for Systemic Anthrax: Analysis of Cases from 1945 to 2014 Identified Through a Systematic Literature Review.

PubMed

Pillai, Satish K; Huang, Eileen; Guarnizo, Julie T; Hoyle, Jamechia D; Katharios-Lanwermeyer, Stefan; Turski, Theresa K; Bower, William A; Hendricks, Katherine A; Meaney-Delman, Dana

2015-01-01

Systemic anthrax is associated with high mortality. Current national guidelines, developed for the individualized treatment of systemic anthrax, outline the use of combination intravenous antimicrobials for a minimum of 2 weeks, bactericidal and protein synthesis inhibitor antimicrobials for all cases of systemic anthrax, and at least 3 antimicrobials with good blood-brain barrier penetration for anthrax meningitis. However, in an anthrax mass casualty incident, large numbers of anthrax cases may create challenges in meeting antimicrobial needs. To further inform our understanding of the role of antimicrobials in treating systemic anthrax, a systematic review of the English-language literature was conducted to identify cases of systemic anthrax treated with antimicrobials for which a clinical outcome was recorded. A total of 149 cases of systemic anthrax were identified. Among the identified 59 cases of cutaneous anthrax, 33 were complicated by meningitis (76% mortality), while 26 simply had evidence of the systemic inflammatory response syndrome (4% mortality); 21 of 26 (81%) of this latter group received monotherapy. Subsequent analysis regarding combination antimicrobial therapy was restricted to the remaining 123 cases of more severe anthrax (overall 67% mortality). Recipients of combination bactericidal and protein synthesis inhibitor therapy had a 45% survival versus 28% in the absence of combination therapy (p = 0.07). For meningitis cases (n = 77), survival was greater for those receiving 3 or more antimicrobials over the course of treatment (3 of 4; 75%), compared to receipt of 1 or 2 antimicrobials (12 of 73; 16%) (p = 0.02). Median parenteral antimicrobial duration was 14 days. Combination bactericidal and protein synthesis inhibitor therapy may be appropriate in severe anthrax disease, particularly anthrax meningitis, in a mass casualty incident.

Cyclooxygenase inhibitors are potent sensitizers of prostate tumours to hyperthermia and radiation.

PubMed

Asea, A; Mallick, R; Lechpammer, S; Ara, G; Teicher, B A; Fiorentino, S; Stevenson, M A; Calderwood, S K

2001-01-01

It has previously been demonstrated that hyperthermia can activate prostaglandin synthesis and that prostaglandins are protective against hyperthermia. This study examined the use of inhibitors of prostaglandin synthesis on the response of prostate tumours to hyperthermia. The non-steroidal anti-inflammatory drugs (NSAID) ibuprofen and sulindac, known cyclooxygenase inhibitors that inhibit prostaglandin production, were effective hyperthermia sensitizers and augmented growth delay of DU-145 and PC-3 prostate tumours to combined radiation and hyperthermia treatment protocols. Pre-treatment of mice with ibuprofen and sulindac at hyperthermia sensitizing doses resulted in significant (p < 0.01) inhibition of hyperthemia-induced serum prostaglandin E2. These findings indicate that NSAID may have both sensitizing effects on prostate tumour growth and may function by inhibiting prostaglandin synthesis.

Synthesis and Biological Evaluation of Botulinum Neurotoxin A Protease Inhibitors

PubMed Central

Li, Bing; Pai, Ramdas; Cardinale, Steven C.; Butler, Michelle M.; Peet, Norton P.; Moir, Donald T.; Bavari, Sina; Bowlin, Terry L.

2010-01-01

NSC 240898 was previously identified as a botulinum neurotoxin A light chain (BoNT/A LC) endopeptidase inhibitor by screening the National Cancer Institute Open Repository diversity set. Two types of analogs have been synthesized and shown to inhibit BoNT/A LC in a FRET-based enzyme assay, with confirmation in an HPLC-based assay. These two series of compounds have also been evaluated for inhibition of anthrax lethal factor (LF), an unrelated metalloprotease, to examine enzyme specificity of the BoNT/A LC inhibition. The most potent inhibitor against BoNT/A LC in these two series is compound 12 (IC50 = 2.5 µM, FRET assay), which is 4.4-fold more potent than the lead structure, and 11.2-fold more selective for BoNT/A LC versus the anthrax LF metalloproteinase. Structure-activity relationship studies have revealed structural features important to potency and enzyme specificity. PMID:20155918

Synthesis, structure elucidation, DNA-PK and PI3K and anti-cancer activity of 8- and 6-aryl-substituted-1-3-benzoxazines.

PubMed

Morrison, Rick; Al-Rawi, Jasim M A; Jennings, Ian G; Thompson, Philip E; Angove, Michael J

2016-03-03

The synthesis of 6-aryl, 8- aryl, and 8-aryl-6-chloro-2-morpholino-1,3-benzoxazines with potent activity against PI3K and DNA-PK is described. Synthesis of thirty one analogues was facilitated by an improved synthesis of 3-bromo-2-hydroxybenzoic acid 13 by de-sulphonation of 3-bromo-2-hydroxy-5-sulfobenzoic acid 12 en route to 2-methylthio-substituted-benzoxazine intermediates 17-19. From this series, compound 20k (LTURM34) (dibenzo[b,d]thiophen-4-yl) (IC50 = 0.034 μM) was identified as a specific DNA-PK inhibitor, 170 fold more selective for DNA-PK activity compared to PI3K activity. Other compounds of the series show markedly altered selectivity for various PI3K isoforms including compound 20i (8-(naphthalen-1-yl) a potent and quite selective PI3Kδ inhibitor (IC50 = 0.64 μM). Finally, nine compounds were evaluated and showed antiproliferative activity against an NCI panel of cancer cell lines. Compound 20i (8-(naphthalen-1-yl) showed strong anti-proliferative activity against A498 renal cancer cells that warrants further investigation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Palmitate-induced ER stress and inhibition of protein synthesis in cultured myotubes does not require Toll-like receptor 4.

PubMed

Perry, Ben D; Rahnert, Jill A; Xie, Yang; Zheng, Bin; Woodworth-Hobbs, Myra E; Price, S Russ

2018-01-01

Saturated fatty acids, such as palmitate, are elevated in metabolically dysfunctional conditions like type 2 diabetes mellitus. Palmitate has been shown to impair insulin sensitivity and suppress protein synthesis while upregulating proteolytic systems in skeletal muscle. Increased sarco/endoplasmic reticulum (ER) stress and subsequent activation of the unfolded protein response may contribute to the palmitate-induced impairment of muscle protein synthesis. In some cell types, ER stress occurs through activation of the Toll-like receptor 4 (TLR4). Given the link between ER stress and suppression of protein synthesis, we investigated whether palmitate induces markers of ER stress and protein synthesis by activating TLR4 in cultured mouse C2C12 myotubes. Myotubes were treated with vehicle, a TLR4-specific ligand (lipopolysaccharides), palmitate, or a combination of palmitate plus a TLR4-specific inhibitor (TAK-242). Inflammatory indicators of TLR4 activation (IL-6 and TNFα) and markers of ER stress were measured, and protein synthesis was assessed using puromycin incorporation. Palmitate substantially increased the levels of IL-6, TNF-α, CHOP, XBP1s, and ATF 4 mRNAs and augmented the levels of CHOP, XBP1s, phospho-PERK and phospho-eIF2α proteins. The TLR4 antagonist attenuated both acute palmitate and LPS-induced increases in IL-6 and TNFα, but did not reduce ER stress signaling with either 6 h or 24 h palmitate treatment. Similarly, treating myotubes with palmitate for 6 h caused a 43% decline in protein synthesis consistent with an increase in phospho-eIF2α, and the TLR4 antagonist did not alter these responses. These results suggest that palmitate does not induce ER stress through TLR4 in muscle, and that palmitate impairs protein synthesis in skeletal muscle in part by induction of ER stress.

Pharmacological characterization of [trans-5'-(4-amino-7,7-dimethyl-2-trifluoromethyl-7H-pyrimido[4,5-b][1,4]oxazin-6-yl)-2',3'-dihydrospiro(cyclohexane-1,1'-inden)-4-yl]acetic acid monobenzenesulfonate (JTT-553), a novel acyl CoA:diacylglycerol transferase (DGAT) 1 inhibitor.

PubMed

Tomimoto, Daisuke; Okuma, Chihiro; Ishii, Yukihito; Akiyama, Yoshiyuki; Ohta, Takeshi; Kakutani, Makoto; Ohkuma, Yoshiaki; Ogawa, Nobuya

2015-01-01

Acyl CoA:diacylglycerol acyltransferase (DGAT) 1 is an enzyme that catalyzes the final step in triglyceride (TG) synthesis. This enzyme is considered to be a potential therapeutic target for obesity and diabetes. Here, results of an investigation of the pharmacological effects of JTT-553 [trans-5'-(4-amino-7,7-dimethyl-2-trifluoromethyl-7H-pyrimido[4,5-b][1,4]oxazin-6-yl)-2',3'-dihydrospiro(cyclohexane-1,1'-inden)-4-yl]acetic acid monobenzenesulfonate, a novel DGAT1 inhibitor, are reported. To measure the inhibitory activity of JTT-553 against DGAT1, TG synthesis using [(14)C]-labeled oleoyl-CoA was evaluated. Similarly, the inhibitory activity of JTT-553 against DGAT2, an isozyme of DGAT1, and acyl-CoA cholesterol acyltransferase (ACAT) 1, which is highly homologous to DGAT1, were evaluated. JTT-553 selectively inhibited human DGAT1 and showed comparable inhibitory effects on the activity of human, rat, and mouse DGAT. In vivo, JTT-553 suppressed plasma TG and chylomicron TG levels after olive oil loading in Sprague-Dawley (SD) rats. JTT-553 also inhibited TG synthesis in epididymal fat after [(14)C] oleic acid injection in C57BL/6J mice. Food intake was evaluated in SD rats fed 3.1%, 13%, or 35% (w/w) fat diets. In rats fed the 35% fat diet, JTT-553 reduced food intake. This reduction of food intake was observed 2 h after feeding, lasted for 24 h, and correlated with dietary fat content. Furthermore, JTT-553 reduced daily food intake and body weight gain in diet-induced obese rats after 4-week repeated administration. JTT-553 exerted multiple effects on intestinal fat absorption, adipose fat synthesis, and food intake, and consequently induced body weight reduction. Therefore, JTT-553 is expected to be an effective novel therapeutic agent for the treatment of obesity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schormann, Norbert; Velu, Sadanandan E.; Murugesan, Srinivasan

Dihydrofolate reductase (DHFR) of the parasite Trypanosoma cruzi (T. cruzi) is a potential target for developing drugs to treat Chagas disease. We have undertaken a detailed structure-activity study of this enzyme. We report here synthesis and characterization of six potent inhibitors of the parasitic enzyme. Inhibitory activity of each compound was determined against T. cruzi and human DHFR. One of these compounds, ethyl 4-(5-[(2,4-diamino-6-quinazolinyl)methyl]amino-2-methoxyphenoxy)butanoate (6b) was co-crystallized with the bifunctional dihydrofolate reductase-thymidylate synthase enzyme of T. cruzi and the crystal structure of the ternary enzyme:cofactor:inhibitor complex was determined. Molecular docking was used to analyze the potential interactions of all inhibitorsmore » with T. cruzi DHFR and human DHFR. Inhibitory activities of these compounds are discussed in the light of enzyme-ligand interactions. Binding affinities of each inhibitor for the respective enzymes were calculated based on the experimental or docked binding mode. An estimated 60-70% of the total binding energy is contributed by the 2,4-diaminoquinazoline scaffold.« less

Antimicrobial Susceptibility/Resistance of Streptococcus Pneumoniae

PubMed Central

Karcic, Emina; Aljicevic, Mufida; Bektas, Sabaheta; Karcic, Bekir

2015-01-01

Introduction: Pneumococcal infections are a major cause of morbidity and mortality worldwide, whose treatment is threatened with an increase in the number of strains resistant to antibiotic therapy. Goal: The main goal of this research was to investigate the presence of antimicrobial susceptibility/resistance of S. pneumoniae. Material and methods: Taken are swabs of the nose and nasopharynx, eye and ear. In vitro tests that were made in order to study the antimicrobial resistance of pneumococci are: disk diffusion method and E-test. Results: The resistance to inhibitors of cell wall synthesis was recorded at 39.17%, protein synthesis inhibitors 19.67%, folate antagonists 47.78% and quinolone in 1.11%. S. pneumoniae has shown drug resistance to erythromycin in 45%, clindamycin in 45%, chloramphenicol–0.56%, rifampicin–6.11%, tetracycline–4.67%, penicillin-G in 4.44%, oxacillin in 73.89%, ciprofloxacin in 1.11% and trimethoprim-sulfamethoxazole in 5.34% of cases. Conclusion: The highest resistance pneumococcus showed to erythromycin, clindamycin and trimethoprim-sulfamethoxazole and these should be avoided in the treatment. The least resistance pneumococcus showed to tetracycline, rifampicin, chloramphenicol, penicillin-G and ciprofloxacin. PMID:26236165

Synthesis of betulinic acid derivatives as entry inhibitors against HIV-1 and bevirimat-resistant HIV-1 variants.

PubMed

Dang, Zhao; Qian, Keduo; Ho, Phong; Zhu, Lei; Lee, Kuo-Hsiung; Huang, Li; Chen, Chin-Ho

2012-08-15

Betulinic acid derivatives modified at the C28 position are HIV-1entry inhibitors such as compound A43D; however, modified at the C3 position instead of C28 give HIV-1 maturation inhibitor such as bevirimat. Bevirimat exhibited promising pharmacokinetic profiles in clinical trials, but its effectiveness was compromised by the high baseline drug resistance of HIV-1 variants with polymorphism in the putative drug binding site. In an effort to determine whether the viruses with bevirimat resistant polymorphism also altered their sensitivities to the betulinic acid derivatives that inhibit HIV-1 entry, a series of new betulinic acid entry inhibitors were synthesized and tested for their activities against HIV-1 NL4-3 and NL4-3 variants resistant to bevirimat. The results show that the bevirimat resistant viruses were approximately 5- to10-fold more sensitive to three new glutamine ester derivatives (13, 15 and 38) and A43D in an HIV-1 multi-cycle replication assay. In contrast, the wild type NL4-3 and the bevirimat resistant variants were equally sensitive to the HIV-1 RT inhibitor AZT. In addition, these three new compounds markedly improved microsomal stability compared to A43D. Copyright © 2012 Elsevier Ltd. All rights reserved.

New hydroxamate inhibitors of neurotensin-degrading enzymes. Synthesis and enzyme active-site recognition.

PubMed

Bourdel, E; Doulut, S; Jarretou, G; Labbe-Jullie, C; Fehrentz, J A; Doumbia, O; Kitabgi, P; Martinez, J

1996-08-01

Selective and mixed inhibitors of the three zinc metallopeptidases that degrade neurotensin (NT), e.g. endopeptidase 24-16 (EC 3.4.24.16), endopeptidase 24-11 (EC 3.4.24.11 or neutral endopeptidase, NEP) and endopeptidase 24-15 (EC 3.4.24.15), and leucine-aminopeptidase (type IV-S), that degrades the NT-related peptides, Neuromedin N (NN), are of great interest. On the structural basis of compound JMV 390-1 (N-[3-[(hydroxyamino)carbonyl]-1-oxo-2(R)-benzylpropyl]-L- isoleucyl-L-leucine), which was a full inhibitor of the major NT degrading enzymes, several hydroxamate inhibitors corresponding to the general formula HONHCO-CH2-CH(CH2-C6H5)CO-X-Y-OH (with X-Y = dipeptide) have been synthesized. Compound 7a (X-Y = Ile-Ala) was nearly 40-times more potent in inhibiting EC 24-16 than NEP and more than 800-times more potent than EC 24-15, with an IC50 (12 nM) almost equivalent to that of compound JMV 390-1. Therefore, this compound is an interesting selective inhibitor of EC 24-16, and should be an interesting probe to explore the physiological involvement of EC 24-16 in the metabolism of neurotensin.

Gi-coupled γ-aminobutyric acid-B receptors cross-regulate phospholipase C and calcium in airway smooth muscle.

PubMed

Mizuta, Kentaro; Mizuta, Fumiko; Xu, Dingbang; Masaki, Eiji; Panettieri, Reynold A; Emala, Charles W

2011-12-01

γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian central nervous system, and exerts its actions via both ionotropic (GABA(A)) and metabotropic (GABA(B)) receptors. Although the functional expression of GABA(B) receptors coupled to the G(i) protein was reported for airway smooth muscle, the role of GABA(B) receptors in airway responsiveness remains unclear. We investigated whether G(i)-coupled GABA(B) receptors cross-regulate phospholipase C (PLC), an enzyme classically regulated by G(q)-coupled receptors in human airway smooth muscle cells. Both the GABA(B)-selective agonist baclofen and the endogenous ligand GABA significantly increased the synthesis of inositol phosphate, whereas GABA(A) receptor agonists, muscimol, and 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol exerted no effect. The baclofen-induced synthesis of inositol phosphate and transient increases in [Ca(2+)](i) were blocked by CGP35348 and CGP55845 (selective GABA(B) antagonists), pertussis toxin (PTX, which inactivates the G(i) protein), gallein (a G(βγ) signaling inhibitor), U73122 (an inhibitor of PLC-β), and xestospongin C, an inositol 1,4,5-triphosphate receptor blocker. Baclofen also potentiated the bradykinin-induced synthesis of inositol phosphate and transient increases in [Ca(2+)](i), which were blocked by CGP35348 or PTX. Moreover, baclofen potentiated the substance P-induced contraction of airway smooth muscle in isolated guinea pig tracheal rings. In conclusion, the stimulation of GABA(B) receptors in human airway smooth muscle cells rapidly mobilizes intracellular Ca(2+) stores by the synthesis of inositol phosphate via the activation of PLC-β, which is stimulated by G(βγ) protein liberated from G(i) proteins coupled to GABA(B) receptors. Furthermore, crosstalk between GABA(B) receptors and G(q)-coupled receptors potentiates the synthesis of inositol phosphate, transient increases in [Ca(2+)](i), and smooth muscle contraction through G(i) proteins.

Gi-Coupled γ-Aminobutyric Acid–B Receptors Cross-Regulate Phospholipase C and Calcium in Airway Smooth Muscle

PubMed Central

Mizuta, Kentaro; Mizuta, Fumiko; Xu, Dingbang; Masaki, Eiji; Panettieri, Reynold A.

2011-01-01

γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian central nervous system, and exerts its actions via both ionotropic (GABAA) and metabotropic (GABAB) receptors. Although the functional expression of GABAB receptors coupled to the Gi protein was reported for airway smooth muscle, the role of GABAB receptors in airway responsiveness remains unclear. We investigated whether Gi-coupled GABAB receptors cross-regulate phospholipase C (PLC), an enzyme classically regulated by Gq-coupled receptors in human airway smooth muscle cells. Both the GABAB-selective agonist baclofen and the endogenous ligand GABA significantly increased the synthesis of inositol phosphate, whereas GABAA receptor agonists, muscimol, and 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol exerted no effect. The baclofen-induced synthesis of inositol phosphate and transient increases in [Ca2+]i were blocked by CGP35348 and CGP55845 (selective GABAB antagonists), pertussis toxin (PTX, which inactivates the Gi protein), gallein (a Gβγ signaling inhibitor), U73122 (an inhibitor of PLC-β), and xestospongin C, an inositol 1,4,5-triphosphate receptor blocker. Baclofen also potentiated the bradykinin-induced synthesis of inositol phosphate and transient increases in [Ca2+]i, which were blocked by CGP35348 or PTX. Moreover, baclofen potentiated the substance P–induced contraction of airway smooth muscle in isolated guinea pig tracheal rings. In conclusion, the stimulation of GABAB receptors in human airway smooth muscle cells rapidly mobilizes intracellular Ca2+ stores by the synthesis of inositol phosphate via the activation of PLC-β, which is stimulated by Gβγ protein liberated from Gi proteins coupled to GABAB receptors. Furthermore, crosstalk between GABAB receptors and Gq-coupled receptors potentiates the synthesis of inositol phosphate, transient increases in [Ca2+]i, and smooth muscle contraction through Gi proteins. PMID:21719794

Epithelial GM-CSF induction by Candida glabrata.

PubMed

Li, L; Dongari-Bagtzoglou, A

2009-08-01

The main cytokine induced by the interaction of oral epithelial cells with C. glabrata is granulocyte monocyte colony-stimulating factor (GM-CSF); however, the mechanisms regulating this response are unknown. Based on previously published information on the interactions of C. albicans with oral epithelial cells, we hypothesized that interaction with viable C. glabrata triggers GM-CSF synthesis via NF-kappaB activation. We found that C. glabrata-induced GM-CSF synthesis was adhesion-dependent, enhanced by endocytosis, and required fungal viability. NF-kappaB activation was noted during interaction of epithelial cells with C. glabrata, and pre-treatment with an NF-kappaB inhibitor partly inhibited GM-CSF synthesis. Blocking TLR4 with anti-TLR4 antibody did not inhibit GM-CSF production. In contrast, an anti-CDw17 antibody triggered significant inhibition of NF-kappaB activation and GM-CSF synthesis. beta-glucans did not stimulate GM-CSF synthesis, suggesting that the CDw17/NF-kappaB/GM-CSF pathway may be beta-glucan-independent. This study provides new insights into the mechanism of GM-CSF induction by C. glabrata.

Indanones as high-potency reversible inhibitors of monoamine oxidase.

PubMed

Mostert, Samantha; Petzer, Anél; Petzer, Jacobus P

2015-05-01

Recent reports document that α-tetralone (3,4-dihydro-2H-naphthalen-1-one) is an appropriate scaffold for the design of high-potency monoamine oxidase (MAO) inhibitors. Based on the structural similarity between α-tetralone and 1-indanone, the present study involved synthesis of 34 1-indanone and related indane derivatives as potential inhibitors of recombinant human MAO-A and MAO-B. The results show that C6-substituted indanones are particularly potent and selective MAO-B inhibitors, with IC50 values ranging from 0.001 to 0.030 μM. C5-Substituted indanone and indane derivatives are comparatively weaker MAO-B inhibitors. Although the 1-indanone and indane derivatives are selective inhibitors of the MAO-B isoform, a number of homologues are also potent MAO-A inhibitors, with three homologues possessing IC50 values <0.1 μM. Dialysis of enzyme-inhibitor mixtures further established a selected 1-indanone as a reversible MAO inhibitor with a competitive mode of inhibition. It may be concluded that 1-indanones are promising leads for the design of therapies for neurodegenerative and neuropsychiatric disorders such as Parkinson's disease and depression. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, Biological Evaluation, and Molecular Docking of (R)-2-((8-(3-aminopiperidin-1-yl)-3-methyl-7-(3-methylbut-2-en-1-yl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)methyl)benzonitrile as Dipeptidyl Peptidase IV Inhibitors.

PubMed

Ran, Yan; Pei, Heying; Shao, Mingfeng; Chen, Lijuan

2016-02-01

Type 2 diabetes (T2D) is classified as a major metabolic disorder, which has affected approximately 194 million people worldwide. DPP-IV inhibitors as a new therapy have shown several advantages over traditional antidiabetic drugs. Based on the similar binding modes of Alogliptin and Linagliptin, molecular operation was conducted via combining pharmacophore hybridization with structural optimization between the two market drugs and racemic compounds 40 and 43 were reported as DPP-IV inhibitors in our previous studies. But the majority of DPP-IV inhibitors have developed into a small molecule with certain conformation; in this study, we described the synthesis, biological evaluation, and molecular docking of corresponding enantiomers of compounds 40 and 43. The most potent inhibitor is (R)-40 (IC50  = 23.5 nm, F = 74.67%, T1/2  = 4 h), which exhibited moderate antihyperglycemic activity as compared to the standard antidiabetic drug Linagliptin in OGTT. In addition, compound (R)-40 effectively improved the pathological state of DIO mice. Molecular docking studies clarified the favorable binding affinity between compound (R)-40 and DPP-IV active site. Thus, compound (R)-40 would be entitled to further development as a drug candidate on the basis of the suitable pharmacokinetic (PK) and desirable pharmacodynamic (PD) profiles. © 2015 John Wiley & Sons A/S.

Selective effects of purine and pyrimidine analogues and of respiratory inhibitors on perithecial development and branching in sordaria.

PubMed

Lindenmayer, A; Schoen, H F

1967-08-01

The initiation of perithecia in the homothallic ascomycete Sordaria fimicola was completely suppressed, without seriously inhibiting vegetative growth, by growing the fungus on an agar medium containing one of the following additions: 1) 1 mum 5-fluorouracil, 2) 10 to 100 mum 6-azauracil, 8-azaguanine or 8-azaadenine, 3) 50 to 500 mum cyanide or azide, 4) 5% (w/v) casein hydrolysate. In contrast to the selective activity of the analogues of 3 RNA bases, whose inhibition could be reversed by the appropriate normal bases only, none of the analogues of thymine were active, neither were the thio-derivatives of RNA bases. Other inhibitors of RNA and protein synthesis, like actinomycin D, puromycin and cycloheximide, were also without selective activity, although the last of these inhibited perithecial maturation at 0.1 mum concentration but not initiation. Amino acid analogues were inactive, as were the metabolic inhibitors thiourea, 2,4-dinitrophenol and fluoride. The compounds which inhibited the formation of perithecia also lowered the branching frequency of leading hyphae, but not their linear growth rates. Consequently, the branch densities were diminished in their presence. Hypotheses to account for these findings are discussed in terms of inhibition of growth in general, of the synthesis of some specific messenger RNAs, and of RNA-mediated transport across membranes, the last of which seeming the most fruitful for further work.

Temporal and pharmacological division of fibroblast cyclooxygenase expression into transcriptional and translational phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raz, A.; Wyche, A.; Needleman, P.

1989-03-01

The authors have recently shown that the synthesis of cyclooxygenase in human dermal fibroblasts is markedly stimulated by the cytokine interleukin 1 (IL-1). They now show that the temporal sequence of the induced synthesis of PG synthase can be separated into an early transcriptional (i.e., actinomycin D inhibitable) phase and a subsequent translational (cycloheximide but not actinomycin D inhibitable) phase and that IL-1 exerts its effect during the transcriptional phase. Phorbol 12-myristate 13-acetate also stimulates synthesis of PG synthase and, together with IL-1, produces a synergistic stimulatory effect. Inhibitors of protein kinase C activation abolished the stimulatory effect of IL-1,more » suggesting that protein kinase C activation is a critical event in the signal-transduction sequence of the IL-1-induced increase of PG synthase synthesis. The antiinflammatory glucocorticosteroids dexamethasone and triamcinolone, but not progesterone or testosterone, were potent inhibitors of PG synthase synthesis when added during the translational phase of the synthesis sequence. The glucocorticosteroid effect was blocked by RNA and protein synthesis inhibitors. This report suggests that glucocorticosteroids exert their effect via a newly synthesized protein, causing a profound translational control of PG synthase synthesis. This novel mechanism of suppression of arachidonate metabolism is distinct from any influence of steroids on phospholipase A{sub 2} activity.« less

A novel five-lipoxygenase activity protein inhibitor labeled with carbon-14 and deuterium.

PubMed

Latli, Bachir; Hrapchak, Matt; Gao, Joe J; Busacca, Carl A; Senanayake, Chris H

2015-07-01

2-[4-(3-{(1R)-1-[4-(2-Aminopyrimidin-5-yl)phenyl]-1-cyclopropylethyl}-1,2,4-oxadiazol-5-yl)-1H-pyrazol-1-yl]-N,N-dimethylacetamide (1), is a novel and selective five-lipoxygenase activity protein (FLAP) inhibitor with excellent pharmacokinetics properties. The availability of a key chiral intermediate allowed the synthesis of [(14) C]-(1) in six radiochemical steps and in 47% overall radiochemical yield with a specific activity of 51 mCi/mmol using carbon-14 zinc cyanide. 2-Chloro-N,N-dimethyl-(2)H6-acetamide was prepared and condensed with a penultimate intermediate to give [(2)H6]-(1) in very high yield and in more than 99% isotopic enrichment. Copyright © 2015 John Wiley & Sons, Ltd.

Arabinosylthymine: inhibitor of splenic lymphocyte macromolecular synthesis in vitro.

PubMed Central

Barnett, J M; McGowan, J J; Gentry, G A

1979-01-01

The effect of arabinosylthymine on lymphocyte transformation was investigated. Arabinosylthymine was demonstrated not to be cytotoxic for hamster spleen lymphocytes but was found to inhibit the increase in deoxyribonucleic acid and protein synthesis usually observed as a result of mitogen stimulation. These findings suggest that, in addition to being a potent anti-herpesvirus inhibitor, arabinosylthymine is also an immunosuppressive agent. PMID:500206

Design, synthesis and molecular simulation studies of dihydrostilbene derivatives as potent tyrosinase inhibitors.

PubMed

Vontzalidou, Argyro; Zoidis, Grigoris; Chaita, Eliza; Makropoulou, Maria; Aligiannis, Nektarios; Lambrinidis, George; Mikros, Emmanuel; Skaltsounis, Alexios-Leandros

2012-09-01

The synthesis, molecular modeling and biological evaluation of substituted deoxybenzoins and optimized dihydrostilbenes are reported. Preliminary structure-activity relationship data were elucidated and lead compounds suitable for further optimization were discovered. Dihydrostilbene 7 is a particularly potent inhibitor (IC(50)=8.44 μM, more potent than kojic acid). Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis, antimalarial properties, and SAR studies of alkoxyurea-based HDAC inhibitors.

PubMed

Hansen, Finn K; Skinner-Adams, Tina S; Duffy, Sandra; Marek, Linda; Sumanadasa, Subathdrage D M; Kuna, Krystina; Held, Jana; Avery, Vicky M; Andrews, Katherine T; Kurz, Thomas

2014-03-01

Histone deacetylase (HDAC) inhibitors are an emerging class of potential antimalarial drugs. We investigated the antiplasmodial properties of 16 alkoxyurea-based HDAC inhibitors containing various cap and zinc binding groups (ZBGs). Ten compounds displayed sub-micromolar activity against the 3D7 line of Plasmodium falciparum. Structure-activity relationship studies revealed that a hydroxamic acid ZBG is crucial for antiplasmodial activity, and that the introduction of bulky alkyl substituents to cap groups increases potency against asexual blood-stage parasites. We also demonstrate that selected compounds cause hyperacetylation of P. falciparum histone H4, indicating inhibition of one or more PfHDACs. To assess the selectivity of alkoxyurea-based HDAC inhibitors for parasite over normal mammalian cells, the cytotoxicity of representative compounds was evaluated against neonatal foreskin fibroblast (NFF) cells. The most active compound, 6-((3-(4-(tert-butyl)phenyl)ureido)oxy)-N-hydroxyhexanamide (1 e, Pf3D7 IC50 : 0.16 μM) was 31-fold more toxic against the asexual blood stages than towards normal mammalian cells. Moreover, a subset of four structurally diverse HDAC inhibitors revealed moderate activity against late-stage (IV-V) gametocytes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure-Based Design, Synthesis, Evaluation And Crystal Structures of Transition State Analogue Inhibitors of Inosine Monophosphate Cyclohydrolase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, L.; Chong, Y.; Hwang, I.

2007-07-13

The inosine monophosphate cyclohydrolase (IMPCH) component (residues 1-199) of the bifunctional enzyme aminoimidazole-4-carboxamide ribonucleotide transformylase (AICAR Tfase, residues 200-593)/IMPCH (ATIC) catalyzes the final step in the de novo purine biosynthesis pathway that produces IMP. As a potential target for antineoplastic intervention, we designed IMPCH inhibitors, 1,5-dihydroimidazo[4,5-c][1,2,6]thiadiazin-4(3H)-one 2,2-dioxide (heterocycle, 1), the corresponding nucleoside (2), and the nucleoside monophosphate (nucleotide) (3), as mimics of the tetrahedral intermediate in the cyclization reaction. All compounds are competitive inhibitors against IMPCH (K(i) values = 0.13-0.23 microm) with the simple heterocycle 1 exhibiting the most potent inhibition (K(i) = 0.13 microm). Crystal structures of bifunctional ATICmore » in complex with nucleoside 2 and nucleotide 3 revealed IMPCH binding modes similar to that of the IMPCH feedback inhibitor, xanthosine 5'-monophosphate. Surprisingly, the simpler heterocycle 1 had a completely different IMPCH binding mode and was relocated to the phosphate binding pocket that was identified from previous xanthosine 5'-monophosphate structures. The aromatic imidazole ring interacts with a helix dipole, similar to the interaction with the phosphate moiety of 3. The crystal structures not only revealed the mechanism of inhibition of these compounds, but they now serve as a platform for future inhibitor improvements. Importantly, the nucleoside-complexed structure supports the notion that inhibitors lacking a negatively charged phosphate can still inhibit IMPCH activity with comparable potency to phosphate-containing inhibitors. Provocatively, the nucleotide inhibitor 3 also binds to the AICAR Tfase domain of ATIC, which now provides a lead compound for the design of inhibitors that simultaneously target both active sites of this bifunctional enzyme.« less

Discovery of mixed type thymidine phosphorylase inhibitors endowed with antiangiogenic properties: synthesis, pharmacological evaluation and molecular docking study of 2-thioxo-pyrazolo[1,5-a][1,3,5]triazin-4-ones. Part II.

PubMed

Bera, Hriday; Ojha, Probir kumar; Tan, Bee Jen; Sun, Lingyi; Dolzhenko, Anton V; Chui, Wai-Keung; Chiu, Gigi Ngar Chee

2014-05-06

In our drug discovery program, a series of 2-thioxo-pyrazolo[1,5-a][1,3,5]triazin-4-ones were designed, synthesized and evaluated for their TP inhibitory potential. All the synthesized analogues conferred a varying degree of TP inhibitory activity, comparable or better than positive control, 7-deazaxanthine (7-DX, 2) (IC50 value = 42.63 μM). A systematic approach to the lead optimization identified compounds 3c and 4a as the most promising TP inhibitors, exhibiting mixed mode of enzyme inhibition. Moreover, selected compounds demonstrated the ability to attenuate the expression of the angiogenic markers (viz. MMP-9 and VEGF) in MDA-MB-231 cells at sublethal concentrations. In addition, molecular docking studies revealed the plausible binding orientation of these inhibitors towards TP, which was in accordance with the experimental results. Taken as a whole, these compounds would constitute a new direction for the design of novel TP inhibitors with promising antiangiogenic properties. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Synthesis of HIV-Maturation Inhibitor BMS-955176 from Betulin by an Enabling Oxidation Strategy.

PubMed

Ortiz, Adrian; Soumeillant, Maxime; Savage, Scott A; Strotman, Neil A; Haley, Matthew; Benkovics, Tamas; Nye, Jeffrey; Xu, Zhongmin; Tan, Yichen; Ayers, Sloan; Gao, Qi; Kiau, Susanne

2017-05-05

A concise and scalable second generation synthesis of HIV maturation inhibitor BMS-955176 is described. The synthesis is framed by an oxidation strategy highlighted by a Cu I mediated aerobic oxidation of betulin, a highly selective PIFA mediated dehydrogenation of an oxime, and a subsequent Lossen rearrangement which occurs through a unique reaction mechanism for the installation of the C17 amino functionality. The synthetic route proceeds in 7 steps with 47% overall yield and begins from the abundant and inexpensive natural product betulin.

Improved synthesis of ADAM10 inhibitor GI254023X.

PubMed

Hoettecke, Nicole; Ludwig, Andreas; Foro, Sabine; Schmidt, Boris

2010-01-01

The metalloproteinases ADAM10 and ADAM17 are involved in various diseases: neurodegeneration, cancer and inflammation. The inhibition of these proteases is a promising target in the treatment of inflammation and cancer. In this study, we present an improved synthesis of the ADAM10 reference inhibitor GI254023X with a higher overall yield, enhanced detection ability and increased acid stability, providing easier handling. This upscaled synthesis, free of diastereomeric intermediates, ensures single-batch identity, thus warranting its reproducibility in further biological investigations. 2010 S. Karger AG, Basel.

Discovery of a novel acyl-CoA: cholesterol acyltransferase inhibitor: the synthesis, biological evaluation, and reduced adrenal toxicity of (4-phenylcoumarin)acetanilide derivatives with a carboxylic acid moiety.

PubMed

Ogino, Masaki; Nakada, Yoshihisa; Negoro, Nobuyuki; Itokawa, Shigekazu; Nishimura, Satoshi; Sanada, Tsukasa; Satomi, Tomoko; Kita, Shunbun; Kubo, Kazuki; Marui, Shogo

2011-01-01

As a part of our research for novel potent and orally available acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors that can be used as anti-atherosclerotic agents, we recently reported the discovery of the (4-phenylcoumarine)acetanilide derivative 1. However, compound 1 showed adrenal toxicity in animal models. In order to search for safer ACAT inhibitors that do not have adrenal toxicity, we examined the inhibitory activity of ACAT in human macrophage and adrenal cells. The introduction of a carboxylic acid moiety on the pendant phenyl ring and the adjustment of the lipophilicity led to the discovery of (2E)-3-[7-chloro-3-[2-[[4-fluoro-2-(trifluoromethyl)phenyl]amino]-2-oxoethyl]-6-methyl-2-oxo-2H-chromen-4-yl]phenyl]acrylic acid (21e), which showed potent ACAT inhibitory activity in macrophages and a selectivity of around 30-fold over adrenal cells. In addition, compound 21e showed high adrenal safety in guinea pigs.

Discovery of Nanomolar Dengue and West Nile Virus Protease Inhibitors Containing a 4-Benzyloxyphenylglycine Residue.

PubMed

Behnam, Mira A M; Graf, Dominik; Bartenschlager, Ralf; Zlotos, Darius P; Klein, Christian D

2015-12-10

The dengue virus (DENV) and West Nile Virus (WNV) NS2B-NS3 proteases are attractive targets for the development of dual-acting therapeutics against these arboviral pathogens. We present the synthesis and extensive biological evaluation of inhibitors that contain benzyl ethers of 4-hydroxyphenylglycine as non-natural peptidic building blocks synthesized via a copper-complex intermediate. A three-step optimization strategy, beginning with fragment growth of the C-terminal 4-hydroxyphenylglycine to the benzyloxy ether, followed by C- and N-terminal optimization, and finally fragment merging generated compounds with in vitro affinities in the low nanomolar range. The most promising derivative reached Ki values of 12 nM at the DENV-2 and 39 nM at the WNV proteases. Several of the newly discovered protease inhibitors yielded a significant reduction of dengue and West Nile virus titers in cell-based assays of virus replication, with an EC50 value of 3.4 μM at DENV-2 and 15.5 μM at WNV for the most active analogue.

Focused library design and synthesis of 2-mercapto benzothiazole linked 1,2,4-oxadiazoles as COX-2/5-LOX inhibitors

NASA Astrophysics Data System (ADS)

Yatam, Satayanarayana; Gundla, Rambabu; Jadav, Surender Singh; Pedavenkatagari, Narayana reddy; Chimakurthy, Jithendra; Rani B, Namratha; Kedam, Thyagaraju

2018-05-01

Mercapto benzothiazole linked 1,2,4-oxadiazole derivatives were designed (4a-u) as new anti-inflammatory agents using bioisosteric approach and docking studies. The docking results clearly indicated that the compounds 4a-u shown good docking interaction towards COX-2 enzyme. In silico drug-like properties were also calculated for compounds (4a-u) and exhibited significant H-bond acceptor ratio. All compounds were synthesized and biologically evaluated using in vitro COX-1, COX-2 and 5-LOX assays. Compound 4k and 4q (IC50 = 6.8 μM and IC50 = 5.0 μM) found to be potent, selective COX-2 inhibitors and display better anti-inflammatory activity than standard Ibuprofen. Compound 4l and 4e found to be potent inhibitors against 5-LOX (IC50 = 5.1 μM and IC50 = 5.5 μM). The in vivo anti-inflammatory activity studies shown that the compounds 4q and 4k effectively reducing the paw edema volume at 3h and 5h than standard drug Ibuprofen. The DPPH radical scavenging activity provided anti-oxidant activity of compound 4e (IC50 = 25.6 μM) than reference standard Ascorbic acid.

Synthesis, in vitro and in vivo studies, and molecular modeling of N-alkylated dextromethorphan derivatives as non-competitive inhibitors of α3β4 nicotinic acetylcholine receptor.

PubMed

Jozwiak, Krzysztof; Targowska-Duda, Katarzyna M; Kaczor, Agnieszka A; Kozak, Joanna; Ligeza, Agnieszka; Szacon, Elzbieta; Wrobel, Tomasz M; Budzynska, Barbara; Biala, Grazyna; Fornal, Emilia; Poso, Antti; Wainer, Irving W; Matosiuk, Dariusz

2014-12-15

9 N-alkylated derivatives of dextromethorphan are synthesized and studied as non-competitive inhibitors of α3β4 nicotinic acetylcholine receptors (nAChRs). In vitro activity towards α3β4 nicotinic acetylcholine receptor is determined using a patch-clamp technique and is in the micromolar range. Homology modeling, molecular docking and molecular dynamics of ligand-receptor complexes in POPC membrane are used to find the mode of interactions of N-alkylated dextromethorphan derivatives with α3β4 nAChR. The compounds, similarly as dextromethorphan, interact with the middle portion of α3β4 nAChR ion channel. Finally, behavioral tests confirmed potential application of the studied compounds for the treatment of addiction. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed

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

2011-03-01

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

(−)-Epigallocatechin gallate but not chlorogenic acid upregulates osteoprotegerin synthesis through regulation of bone morphogenetic protein-4 in osteoblasts

PubMed Central

Fujita, Kazuhiko; Otsuka, Takanobu; Yamamoto, Naohiro; Kainuma, Shingo; Ohguchi, Reou; Kawabata, Tetsu; Sakai, Go; Kuroyanagi, Gen; Matsushima-Nishiwaki, Rie; Kozawa, Osamu; Tokuda, Haruhiko

2017-01-01

Chlorogenic acid (CGA) is a primary phenolic component of coffee and (−)-epigallocatechin gallate (EGCG) is a primary flavonoid component of green tea, both of which have been documented to possess beneficial health properties. A previous study by the present authors demonstrated that p38 mitogen-activated protein kinase (MAPK) may be associated with osteoprotegerin synthesis stimulated by bone morphogenetic protein-4 (BMP-4) in osteoblast-like MC3T3-E1 cells. In the present study, the effects of CGA and EGCG on BMP-4-stimulated osteoprotegerin synthesis in MC3T3-E1 cells were investigated. It was observed that CGA had no effect on osteoprotegerin release stimulated by BMP-4, whereas EGCG significantly enhanced BMP-4-stimulated osteoprotegerin release (P=0.003). Levels of osteoprotegerin mRNA expression induced by BMP-4 were also significantly increased by EGCG (P=0.03). By contrast, EGCG had no significant effect on phosphorylation of Smad1 or p38 MAPK induced by BMP-4. In addition, EGCG had little effect on BMP-induced phosphorylation of p70 S6 kinase; however rapamycin, as an inhibitor of p70 S6 kinase, significantly suppressed osteoprotegerin release (P=0.007). These data suggest that EGCG but not CGA may upregulate the synthesis of osteoprotegerin induced by BMP-4 in osteoblasts. PMID:28672948

(-)-Epigallocatechin gallate but not chlorogenic acid upregulates osteoprotegerin synthesis through regulation of bone morphogenetic protein-4 in osteoblasts.

PubMed

Fujita, Kazuhiko; Otsuka, Takanobu; Yamamoto, Naohiro; Kainuma, Shingo; Ohguchi, Reou; Kawabata, Tetsu; Sakai, Go; Kuroyanagi, Gen; Matsushima-Nishiwaki, Rie; Kozawa, Osamu; Tokuda, Haruhiko

2017-07-01

Chlorogenic acid (CGA) is a primary phenolic component of coffee and (-)-epigallocatechin gallate (EGCG) is a primary flavonoid component of green tea, both of which have been documented to possess beneficial health properties. A previous study by the present authors demonstrated that p38 mitogen-activated protein kinase (MAPK) may be associated with osteoprotegerin synthesis stimulated by bone morphogenetic protein-4 (BMP-4) in osteoblast-like MC3T3-E1 cells. In the present study, the effects of CGA and EGCG on BMP-4-stimulated osteoprotegerin synthesis in MC3T3-E1 cells were investigated. It was observed that CGA had no effect on osteoprotegerin release stimulated by BMP-4, whereas EGCG significantly enhanced BMP-4-stimulated osteoprotegerin release (P=0.003). Levels of osteoprotegerin mRNA expression induced by BMP-4 were also significantly increased by EGCG (P=0.03). By contrast, EGCG had no significant effect on phosphorylation of Smad1 or p38 MAPK induced by BMP-4. In addition, EGCG had little effect on BMP-induced phosphorylation of p70 S6 kinase; however rapamycin, as an inhibitor of p70 S6 kinase, significantly suppressed osteoprotegerin release (P=0.007). These data suggest that EGCG but not CGA may upregulate the synthesis of osteoprotegerin induced by BMP-4 in osteoblasts.

Design and synthesis of a biaryl series as inhibitors for the bromodomains of CBP/P300.

PubMed

Lai, Kwong Wah; Romero, F Anthony; Tsui, Vickie; Beresini, Maureen H; de Leon Boenig, Gladys; Bronner, Sarah M; Chen, Kevin; Chen, Zhongguo; Choo, Edna F; Crawford, Terry D; Cyr, Patrick; Kaufman, Susan; Li, Yingjie; Liao, Jiangpeng; Liu, Wenfeng; Ly, Justin; Murray, Jeremy; Shen, Weichao; Wai, John; Wang, Fei; Zhu, Caicai; Zhu, Xiaoyu; Magnuson, Steven

2018-01-01

A novel, potent, and orally bioavailable inhibitor of the bromodomain of CBP, compound 35 (GNE-207), has been identified through SAR investigations focused on optimizing al bicyclic heteroarene to replace the aniline present in the published GNE-272 series. Compound 35 has excellent CBP potency (CBP IC 50  = 1 nM, MYC EC 50  = 18 nM), a selectively index of >2500-fold against BRD4(1), and exhibits a good pharmacokinetic profile. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microwave-assisted synthesis of N-pyrazole ureas and the p38alpha inhibitor BIRB 796 for study into accelerated cell ageing.

PubMed

Bagley, Mark C; Davis, Terence; Dix, Matthew C; Widdowson, Caroline S; Kipling, David

2006-11-21

Microwave irradiation of substituted hydrazines and beta-ketoesters gives 5-aminopyrazoles in excellent yield, which can be transformed to the corresponding N-carbonyl derivatives by treatment with an isocyanate or chloroformate. Derivatization of 4-nitronaphth-1-ol using predominantly microwave heating methods and reaction with an N-pyrazole carbamate provides a rapid route to the N-pyrazole urea BIRB 796 in high purity, as a potent and selective inhibitor of p38alpha mitogen-activated protein kinase for the study of accelerated ageing in Werner syndrome cells.

Synthesis, structure-activity relationship and molecular docking of cyclohexenone based analogous as potent non-nucleoside reverse-transcriptase inhibitors

NASA Astrophysics Data System (ADS)

Nazar, Muhammad Faizan; Abdullah, Muhammad Imran; Badshah, Amir; Mahmood, Asif; Rana, Usman Ali; Khan, Salah Ud-Din

2015-04-01

The chalcones core in compounds is advantageously chosen effective synthons, which offer exciting perspectives in biological and pharmacological research. The present study reports the successful development of eight new cyclohexenone based anti-reverse transcriptase analogous using rational drug design synthesis principles. These new cyclohexenone derivatives (CDs) were synthesized by following a convenient route of Robinson annulation, and the molecular structure of these CDs were later confirmed by various analytical techniques such as 1H NMR, 13C NMR, FT-IR, UV-Vis spectroscopy and mass spectrometry. All the synthesized compounds were screened theoretically and experimentally against reverse transcriptase (RT) and found potentially active reverse transcriptase (RT) inhibitors. Of the compounds studied, the compound 2FC4 showed high interaction with RT at non-nucleoside binding site, contributing high free binding energy (ΔG -8.01 Kcal) and IC50 (0.207 μg/ml), respectively. Further results revealed that the compounds bearing more halogen groups, with additional hydrophobic character, offered superior anti-reverse transcriptase activity as compared to rest of compounds. It is anticipate that the present study would be very useful for the selection of potential reverse transcriptase inhibitors featuring inclusive pharmacological profiles.

Discovery of novel aldose reductase inhibitors using a protein structure-based approach: 3D-database search followed by design and synthesis.

PubMed

Iwata, Y; Arisawa, M; Hamada, R; Kita, Y; Mizutani, M Y; Tomioka, N; Itai, A; Miyamoto, S

2001-05-24

Aldose reductase (AR) has been implicated in the etiology of diabetic complications. Due to the limited number of currently available drugs for the treatment of diabetic complications, we have carried out structure-based drug design and synthesis in an attempt to find new types of AR inhibitors. With the ADAM&EVE program, a three-dimensional database (ACD3D) was searched using the ligand binding site of the AR crystal structure. Out of 179 compounds selected through this search followed by visual inspection, 36 compounds were purchased and subjected to a biological assay. Ten compounds showed more than 40% inhibition of AR at a 15 microg/mL concentration. In a subsequent lead optimization, a series of analogues of the most active compound were synthesized based on the docking mode derived by ADAM&EVE. Many of these congeners exhibited higher activities compared to the mother compound. Indeed, the most potent, synthesized compound showed an approximately 20-fold increase in inhibitory activity (IC(50) = 0.21 vs 4.3 microM). Furthermore, a hydrophobic subsite was newly inferred, which would be useful for the design of inhibitors with improved affinity for AR.

In vitro expression of Escherichia coli ribosomal protein genes: autogenous inhibition of translation.

PubMed Central

Yates, J L; Arfsten, A E; Nomura, M

1980-01-01

Escherichia coli ribosomal protein L1 (0.5 micro M) was found to inhibit the synthesis of both proteins of the L11 operon, L11 and L1, but not the synthesis of other proteins directed by lambda rifd 18 DNA. Similarly, S4 (1 micro M) selectively inhibited the synthesis of three proteins of the alpha operon, S13, S11, and S4, directed by lambda spcI DNA or a restriction enzyme fragment obtained from this DNA. S8 (3.6 micro M) also showed preferential inhibitory effects on the synthesis of some proteins encoded in the spc operon, L24 and L5 (and probably S14 and S8), directed by lambda spcl DNA or a restriction enzyme fragment carrying the genes for these proteins. The inhibitory effect of L1 was observed only with L1 and not with other proteins examined, including S4 and S8. Similarly, the effect of S4 was not observed with L1 or S8, and that of S8 was not seen with L1 or S4. Inhibition was shown to take place at the level of translation rather than transcription. Thus, at least some ribosomal proteins (L1 S4, and S8) have the ability to cause selective translational inhibition of the synthesis of certain ribosomal proteins whose genes are in the same operon as their own. These results support the hypothesis that certain free ribosomal proteins not assembled into ribosomes act as "autogenous" feedback inhibitors to regulate the synthesis of ribosomal proteins. Images PMID:6445562

Synthesis and biological evaluation of novel thiadiazole amides as potent Cdc25B and PTP1B inhibitors.

PubMed

Li, Yingjun; Yu, Yang; Jin, Kun; Gao, Lixin; Luo, Tongchuan; Sheng, Li; Shao, Xin; Li, Jia

2014-09-01

A series of novel thiadiazole amide derivatives have been synthesized and evaluated for inhibitory activities against Cdc25B and PTP1B. Most of them showed inhibitory activities against Cdc25B (IC50=1.18-8.01 μg/mL) and PTP1B (IC50=0.85-8.75 μg/mL), respectively. Moreover, compounds 5b and 4l were most potent with IC50 values of 1.18 and 0.85 μg/mL for Cdc25B and PTP1B, respectively, compared with reference drugs Na3VO4 (IC50=0.93 μg/mL) and oleanolic acid (IC50=0.85 μg/mL). The results of selectivity experiments showed that the target compounds were selective inhibitors against PTP1B and Cdc25B. Enzyme kinetic experiments demonstrated that compound 5k was a specific inhibitor with the typical characteristics of a mixed inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of a 3β-hydroxysteroid Dehydrogenase Inhibitor, Trilostane, on the Fathead Minnow Reproductive Axis

EPA Science Inventory

A number of environmental contaminants and plant flavonoid compounds have been shown to inhibit the activity of 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD). Because 3β-HSD plays a critical role in steroid hormone synthesis, inhibition of 3β-HSD represents a potentia...

Discovery, SAR, and X-ray Binding Mode Study of BCATm Inhibitors from a Novel DNA-Encoded Library

PubMed Central

2015-01-01

As a potential target for obesity, human BCATm was screened against more than 14 billion DNA encoded compounds of distinct scaffolds followed by off-DNA synthesis and activity confirmation. As a consequence, several series of BCATm inhibitors were discovered. One representative compound (R)-3-((1-(5-bromothiophene-2-carbonyl)pyrrolidin-3-yl)oxy)-N-methyl-2′-(methylsulfonamido)-[1,1′-biphenyl]-4-carboxamide (15e) from a novel compound library synthesized via on-DNA Suzuki–Miyaura cross-coupling showed BCATm inhibitory activity with IC50 = 2.0 μM. A protein crystal structure of 15e revealed that it binds to BCATm within the catalytic site adjacent to the PLP cofactor. The identification of this novel inhibitor series plus the establishment of a BCATm protein structure provided a good starting point for future structure-based discovery of BCATm inhibitors. PMID:26288694

Phenylalanine and Phenylglycine Analogues as Arginine Mimetics in Dengue Protease Inhibitors.

PubMed

Weigel, Lena F; Nitsche, Christoph; Graf, Dominik; Bartenschlager, Ralf; Klein, Christian D

2015-10-08

Dengue virus is an increasingly global pathogen. One of the promising targets for antiviral drug discovery against dengue and related flaviviruses such as West Nile virus is the viral serine protease NS2B-NS3. We here report the synthesis and in vitro characterization of potent peptidic inhibitors of dengue virus protease that incorporate phenylalanine and phenylglycine derivatives as arginine-mimicking groups with modulated basicity. The most promising compounds were (4-amidino)-L-phenylalanine-containing inhibitors, which reached nanomolar affinities against dengue virus protease. The type and position of the substituents on the phenylglycine and phenylalanine side chains has a significant effect on the inhibitory activity against dengue virus protease and selectivity against other proteases. In addition, the non-natural, basic amino acids described here may have relevance for the development of other peptidic and peptidomimetic drugs such as inhibitors of the blood clotting cascade.

Synthesis of Novel Caspase Inhibitors for Characterization of the Active Caspase Proteome in Vitro and in Vivo

PubMed Central

Henzing, Alexander J.; Dodson, Helen; Reid, Joel M.; Kaufmann, Scott H.; Baxter, Robert L.; Earnshaw, William C.

2008-01-01

Caspases are cysteine proteases that are essential for cytokine maturation and apoptosis. To facilitate the dissection of caspase function in vitro and in vivo, we have synthesized irreversible caspase inhibitors with biotin attached via linker arms of various lengths (12a–d) and a 2,4-dinitrophenyl labeled inhibitor (13). Affinity labeling of apoptotic extracts followed by blotting reveals that these affinity probes detect active caspases. Using the strong affinity of avidin for biotin, we have isolated affinity-labeled caspase-6 from apoptotic cytosolic extracts of cells overexpressing procaspase 6 by treatment with 12c, which contains biotin attached to the Nε-lysine of the inhibitor by a 22.5 Å linker arm, followed by affinity purification on monomeric avidin-Sepharose beads. 13 has proven sufficiently cell permeable to rescue cells from apoptotic execution. These novel caspase inhibitors should provide powerful probes for the study of the active caspase proteome during apoptosis both in vitro and in vivo. PMID:17181147

Chemoproteomics-Aided Medicinal Chemistry for the Discovery of EPHA2 Inhibitors.

PubMed

Heinzlmeir, Stephanie; Lohse, Jonas; Treiber, Tobias; Kudlinzki, Denis; Linhard, Verena; Gande, Santosh Lakshmi; Sreeramulu, Sridhar; Saxena, Krishna; Liu, Xiaofeng; Wilhelm, Mathias; Schwalbe, Harald; Kuster, Bernhard; Médard, Guillaume

2017-06-21

The receptor tyrosine kinase EPHA2 has gained attention as a therapeutic drug target for cancer and infectious diseases. However, EPHA2 research and EPHA2-based therapies have been hampered by the lack of selective small-molecule inhibitors. Herein we report the synthesis and evaluation of dedicated EPHA2 inhibitors based on the clinical BCR-ABL/SRC inhibitor dasatinib as a lead structure. We designed hybrid structures of dasatinib and the previously known EPHA2 binders CHEMBL249097, PD-173955, and a known EPHB4 inhibitor in order to exploit both the ATP pocket entrance as well as the ribose pocket as binding epitopes in the kinase EPHA2. Medicinal chemistry and inhibitor design were guided by a chemical proteomics approach, allowing early selectivity profiling of the newly synthesized inhibitor candidates. Concomitant protein crystallography of 17 inhibitor co-crystals delivered detailed insight into the atomic interactions that underlie the structure-affinity relationship. Finally, the anti-proliferative effect of the inhibitor candidates was confirmed in the glioblastoma cell line SF-268. In this work, we thus discovered a novel EPHA2 inhibitor candidate that features an improved selectivity profile while maintaining potency against EPHA2 and anticancer activity in SF-268 cells. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design, synthesis, kinetic mechanism and molecular docking studies of novel 1-pentanoyl-3-arylthioureas as inhibitors of mushroom tyrosinase and free radical scavengers.

PubMed

Larik, Fayaz Ali; Saeed, Aamer; Channar, Pervaiz Ali; Muqadar, Urooj; Abbas, Qamar; Hassan, Mubashir; Seo, Sung-Yum; Bolte, Michael

2017-12-01

A series of novel 1-pentanoyl-3-arylthioureas was designed as new mushroom tyrosinase inhibitors and free radical scavengers. The title compounds were obtained in excellent yield and characterized by FTIR, 1 H NMR, 13 C NMR and X-ray crystallography in case of compound (4a). The inhibitory effects on mushroom tyrosinase and DPPH were evaluated and it was observed that 1-Pentanoyl-3-(4-methoxyphenyl) thiourea (4f) showed tyrosinase inhibitory activity (IC 50 1.568 ± 0.01 mM) comparable to Kojic acid (IC 50 16.051 ± 1.27 mM). Interestingly compound 4f exhibited higher antioxidant potential compared to other derivatives. The docking studies of synthesized 1-Pentanoyl-3-arylthioureas analogues were also carried out against tyrosinase protein (PDBID 2ZMX) to compare the binding affinities with IC 50 values. The predicted binding affinities are in good agreement with the IC 50 values as compound (4f) showed highest binding affinity (-7.50 kcal/mol) compared to others derivatives. The kinetic mechanism analyzed by Line-weavere Burk plots exhibited that compound (4f) inhibit the enzyme inhibits the tyrosinase non-competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (4f) is 1.10 μM. It was also found from kinetic analysis that derivative 4f irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound (4f) may serve as lead structure for the design of more potent tyrosinase inhibitors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

New agents for prostate cancer.

PubMed

Agarwal, N; Di Lorenzo, G; Sonpavde, G; Bellmunt, J

2014-09-01

The therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC) has been revolutionized by the arrival of multiple novel agents in the past 2 years. Immunotherapy in the form of sipuleucel-T, androgen axis inhibitors, including abiraterone acetate and enzalutamide, a chemotherapeutic agent, cabazitaxel, and a radiopharmaceutical, radium-223, have all yielded incremental extensions of survival and have been recently approved. A number of other agents appear promising in early studies, suggesting that the armamentarium against castrate-resistant prostate cancer is likely to continue to expand. Emerging androgen pathway inhibitors include androgen synthesis inhibitors (TAK700), androgen receptor inhibitors (ARN-509, ODM-201), AR DNA binding domain inhibitors (EPI-001), selective AR downregulators or SARDs (AZD-3514), and agents that inhibit both androgen synthesis and receptor binding (TOK-001/galeterone). Promising immunotherapeutic agents include poxvirus vaccines and CTLA-4 inhibitor (ipilimumab). Biologic agents targeting the molecular drivers of disease are also being investigated as single agents, including cabozantinib (Met and VEGFR2 inhibitor) and tasquinimod (angiogenesis and immune modulatory agent). Despite the disappointing results seen from studies evaluating docetaxel in combination with other agents, including GVAX, anti-angiogentic agents (bevacizumab, aflibercept, lenalinomide), a SRC kinase inhibitor (dasatinib), endothelin receptor antagonists (atrasentan, zibotentan), and high-dose calcitriol (DN-101), the results from the trial evaluating docetaxel in combination with the clusterin antagonist, custirsen, are eagerly awaited. New therapeutic hurdles consist of discovering new targets, understanding resistance mechanisms, the optimal sequencing and combinations of available agents, as well as biomarkers predictive for benefit. Novel agents targeting bone metastases are being developed following the success of zoledronic acid and denosumab. Finally, all of these modalities do not appear curative, suggesting that clinical trial enrollment and a better understanding of biology remain of paramount importance. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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

PubMed

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

2012-06-01

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

Novel contraceptive targets to inhibit ovulation: the prostaglandin E2 pathway

PubMed Central

Duffy, Diane M.

2015-01-01

BACKGROUND Prostaglandin E2 (PGE2) is an essential intrafollicular regulator of ovulation. In contrast with the one-gene, one-protein concept for synthesis of peptide signaling molecules, production and metabolism of bioactive PGE2 requires controlled expression of many proteins, correct subcellular localization of enzymes, coordinated PGE2 synthesis and metabolism, and prostaglandin transport in and out of cells to facilitate PGE2 action and degradation. Elevated intrafollicular PGE2 is required for successful ovulation, so disruption of PGE2 synthesis, metabolism or transport may yield effective contraceptive strategies. METHODS This review summarizes case reports and studies on ovulation inhibition in women and macaques treated with cyclooxygenase inhibitors published from 1987 to 2014. These findings are discussed in the context of studies describing levels of mRNA, protein, and activity of prostaglandin synthesis and metabolic enzymes as well as prostaglandin transporters in ovarian cells. RESULTS The ovulatory surge of LH regulates the expression of each component of the PGE2 synthesis-metabolism-transport pathway within the ovulatory follicle. Data from primary ovarian cells and cancer cell lines suggest that enzymes and transporters can cooperate to optimize bioactive PGE2 levels. Elevated intrafollicular PGE2 mediates key ovulatory events including cumulus expansion, follicle rupture and oocyte release. Inhibitors of the prostaglandin-endoperoxide synthase 2 (PTGS2) enzyme (also known as cyclooxygenase-2 or COX2) reduce ovulation rates in women. Studies in macaques show that PTGS2 inhibitors can reduce the rates of cumulus expansion, oocyte release, follicle rupture, oocyte nuclear maturation and fertilization. A PTGS2 inhibitor reduced pregnancy rates in breeding macaques when administered to simulate emergency contraception. However, PTGS2 inhibition did not prevent pregnancy in monkeys when administered to simulate monthly contraceptive use. CONCLUSION PTGS2 inhibitors alone may be suitable for use as emergency contraceptives. However, drugs of this class are unlikely to be effective as monthly contraceptives. Inhibitors of additional PGE2 synthesis enzymes or modulation of PGE2 metabolism or transport also hold potential for reducing follicular PGE2 and preventing ovulation. Approaches which target multiple components of the PGE2 synthesis-metabolism-transport pathway may be required to effectively block ovulation and lead to the development of novel contraceptive options for women. Therapies which target PGE2 may also impact disorders of the uterus and could also have benefits for women's health in addition to contraception. PMID:26025453

Neo-synthesis of estrogenic or androgenic neurosteroids determine whether long-term potentiation or depression is induced in hippocampus of male rat.

PubMed

Di Mauro, Michela; Tozzi, Alessandro; Calabresi, Paolo; Pettorossi, Vito Enrico; Grassi, Silvarosa

2015-01-01

Estrogenic and androgenic steroids synthesized in the brain may rapidly modulate synaptic plasticity interacting with specific membrane receptors. We explored by electrophysiological recordings in hippocampal slices of male rat the influence of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) neo-synthesis on the synaptic changes induced in the CA1 region. Induction of long-term depression (LTD) and depotentiation (DP) by low frequency stimulation (LFS, 15 min-1 Hz) and of long-term potentiation (LTP) by high frequency stimulation (HFS, 1 s-100 Hz), medium (MFS, 1 s-50 Hz), or weak (WFS, 1 s-25 Hz) frequency stimulation was assayed under inhibitors of enzymes converting testosterone (T) into DHT (5α-reductase) and T into E2 (P450-aromatase). We found that LFS-LTD depends on DHT synthesis, since it was fully prevented under finasteride, an inhibitor of DHT synthesis, and rescued by exogenous DHT, while the E2 synthesis was not involved. Conversely, the full development of HFS-LTP requires the synthesis of E2, as demonstrated by the LTP reduction observed under letrozole, an inhibitor of E2 synthesis, and its full rescue by exogenous E2. For intermediate stimulation protocols DHT, but not E2 synthesis, was involved in the production of a small LTP induced by WFS, while the E2 synthesis was required for the MFS-dependent LTP. Under the combined block of DHT and E2 synthesis all stimulation frequencies induced partial LTP. Overall, these results indicate that DHT is required for converting the partial LTP into LTD whereas E2 is needed for the full expression of LTP, evidencing a key role of the neo-synthesis of sex neurosteroids in determining the direction of synaptic long-term effects.

Lipoteichoic acid synthesis inhibition in combination with antibiotics abrogates growth of multidrug-resistant Enterococcus faecium.

PubMed

Paganelli, Fernanda L; van de Kamer, Tim; Brouwer, Ellen C; Leavis, Helen L; Woodford, Neil; Bonten, Marc J M; Willems, Rob J L; Hendrickx, Antoni P A

2017-03-01

Enterococcus faecium is a multidrug-resistant (MDR) nosocomial pathogen causing significant morbidity in debilitated patients. New antimicrobials are needed to treat antibiotic-resistant E. faecium infections in hospitalised patients. E. faecium incorporates lipoteichoic acid (LTA) (1,3-polyglycerol-phosphate linked to glycolipid) in its cell wall. The small-molecule inhibitor 1771 [2-oxo-2-(5-phenyl-1,3,4-oxadiazol-2-ylamino)ethyl 2-naphtho[2,1-b]furan-1-ylacetate] specifically blocks the activity of Staphylococcus aureus LtaS synthase, which polymerises 1,3-glycerolphosphate into LTA polymers. Here we characterised the effects of the small-molecule inhibitor 1771 on the growth of E. faecium isolates, alone (28 strains) or in combination with the antibiotics vancomycin, daptomycin, ampicillin, gentamicin or linezolid (15 strains), and on biofilm formation (16 strains). Inhibition of LTA synthesis at the surface of the cell by compound 1771 in combination with current antibiotic therapy abrogates enterococcal growth in vitro but does not affect mature E. faecium biofilms. Targeting LTA synthesis may provide new possibilities to treat MDR E. faecium infections. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Total Synthesis and Biological Evaluation of 22-Hydroxyacuminatine

PubMed Central

Xiao, Xiangshu; Antony, Smitha; Pommier, Yves; Cushman, Mark

2008-01-01

A total synthesis of 22-hydroxyacuminatine, a cytotoxic alkaloid isolated from Camptotheca acuminata, is reported. The key step in the synthesis involves the reaction of 2,3-dihydro-1H-pyrrolo[3,4-b]quinoline with a brominated phthalide to generate a substituted pentacyclic 12H-5,11a-diazadibenzo[b,h]fluoren-11-one intermediate. Despite its structural resemblance to camptothecin and luotonin A, a biological evaluation of 22-hydroxyacuminatine in a topoisomerase I-deficient cell line P388/CPT45 has confirmed that the observed cytotoxicity is not due to topoisomerase I inhibition. This result is consistent with the hypothesis that π-π stacking is more important than hydrogen bonding interactions in determining topoisomerase I inhibitor binding in the ternary cleavage complex. PMID:16480276

Novel CYP17 inhibitors: synthesis, biological evaluation, structure-activity relationships and modelling of methoxy- and hydroxy-substituted methyleneimidazolyl biphenyls.

PubMed

Hille, Ulrike E; Hu, Qingzhong; Vock, Carsten; Negri, Matthias; Bartels, Marc; Müller-Vieira, Ursula; Lauterbach, Thomas; Hartmann, Rolf W

2009-07-01

Recently, the steroidal CYP17 inhibitor Abiraterone entered phase II clinical trial for the treatment of androgen-dependent prostate cancer. As 17alpha-hydroxylase-17,20-lyase (CYP17) catalyzes the last step in androgen biosynthesis, inhibition of this target should affect not only testicular but also adrenal androgen formation. Therefore CYP17 inhibitors should be advantageous over existing therapies, for example with GnRH analogues. However, steroidal drugs are known for side effects which are due to affinities for steroid receptors. Therefore we decided to synthesize non-steroidal compounds mimicking the natural CYP17 substrates pregnenolone and progesterone. The synthesis and biological evaluation of a series of 15 novel and highly active non-steroidal CYP17 inhibitors are reported. The compounds were prepared via Suzuki-cross-coupling, Grignard reaction and CDI-assisted S(N)t-reaction with imidazole and their inhibitory activity was examined with recombinant human CYP17 expressed in Escherichia coli. Promising compounds were further tested for their selectivity against the hepatic enzyme CYP3A4 and the glucocorticoid-forming enzyme CYP11B1. All compounds turned out to be potent CYP17 inhibitors. The most active compounds 7 and 8 were much more active than Ketoconazole showing activity comparable to Abiraterone (IC(50) values of 90 and 52nM vs. 72nM). Most compounds also showed higher selectivities than Ketoconazole, but turned out to be less selective than Abiraterone. Docking studies using our CYP17 protein model were performed with selected compounds to study the interactions between the inhibitors and the amino acid residues of the active site.

Synthesis, biological assessment and molecular modeling of new multipotent MAO and cholinesterase inhibitors as potential drugs for the treatment of Alzheimer's disease.

PubMed

Samadi, Abdelouahid; Chioua, Mourad; Bolea, Irene; de Los Ríos, Cristóbal; Iriepa, Isabel; Moraleda, Ignacio; Bastida, Agatha; Esteban, Gerard; Unzeta, Mercedes; Gálvez, Enrique; Marco-Contelles, José

2011-09-01

The synthesis, biological evaluation and molecular modeling of new multipotent inhibitors of type I and type II, able to simultaneously inhibit monoamine oxidases (MAO) as well as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), is described. Compounds of type I were prepared by sequential reaction of 2,6-dichloro-4-phenylpyridine-3,5-dicarbonitrile (14) [or 2,6-dichloropyridine-3,5-dicarbonitrile (15)] with prop-2-yn-1-amine (or N-methylprop-2-yn-1-amine) and 2-(1-benzyl-piperidin-4-yl)alkylamines 22-25. Compounds of type II were prepared by Friedländer type reaction of 6-amino-5-formyl-2-(methyl(prop-2-yn-1-yl)amino)nicotinonitriles 32 and 33 with 4-(1-benzylpiperidin-4-yl)butan-2-one (31). The biological evaluation of molecules 1-11 showed that most of these compounds are potent, in the nanomolar range, and selective AChEI, with moderate and equipotent selectivity for MAO-A and MAO-B inhibition. Kinetic studies of compound 8 proved that this is a EeAChE mixed type inhibitor (IC(50) = 16 ± 2; Ki = 12 ± 3 nM). Molecular modeling investigation on compound 8 confirmed its dual AChE inhibitory profile, binding simultaneously at the catalytic active site (CAS) and at the peripheric anionic site (PAS). In overall, compound 11, as a potent and selective dual AChEI, showing a moderate and selective MAO-A inhibitory profile, can be considered as an attractive multipotent drug for further development on two key pharmacological targets playing key roles in the therapy of Alzheimer's disease. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Synthesis of Barbiturate-Based Methionine Aminopeptidase-1 Inhibitors

PubMed Central

Haldar, Manas K.; Scott, Michael D.; Sule, Nitesh; Srivastava, D. K.; Mallik, Sanku

2008-01-01

The syntheses of a new class of barbiturate-based inhibitors for human and E. Coli Methionine Aminopeptidase -1 (MetAP-1) are described. Some of the synthesized inhibitors show selective inhibition of the human enzyme with high potency. PMID:18343108

Role of Akt/PKB and PFKFB isoenzymes in the control of glycolysis, cell proliferation and protein synthesis in mitogen-stimulated thymocytes.

PubMed

Houddane, Amina; Bultot, Laurent; Novellasdemunt, Laura; Johanns, Manuel; Gueuning, Marie-Agnès; Vertommen, Didier; Coulie, Pierre G; Bartrons, Ramon; Hue, Louis; Rider, Mark H

2017-06-01

Proliferating cells depend on glycolysis mainly to supply precursors for macromolecular synthesis. Fructose 2,6-bisphosphate (Fru-2,6-P 2 ) is the most potent positive allosteric effector of 6-phosphofructo-1-kinase (PFK-1), and hence of glycolysis. Mitogen stimulation of rat thymocytes with concanavalin A (ConA) led to time-dependent increases in lactate accumulation (6-fold), Fru-2,6-P 2 content (4-fold), 6-phosphofructo-2-kinase (PFK-2)/fructose-2,6-bisphosphatase isoenzyme 3 and 4 (PFKFB3 and PFKFB4) protein levels (~2-fold and ~15-fold, respectively) and rates of cell proliferation (~40-fold) and protein synthesis (10-fold) after 68h of incubation compared with resting cells. After 54h of ConA stimulation, PFKFB3 mRNA levels were 45-fold higher than those of PFKFB4 mRNA. Although PFKFB3 could be phosphorylated at Ser461 by protein kinase B (PKB) in vitro leading to PFK-2 activation, PFKFB3 Ser461 phosphorylation was barely detectable in resting cells and only increased slightly in ConA-stimulated cells. On the other hand, PFKFB3 and PFKFB4 mRNA levels were decreased (90% and 70%, respectively) by exposure of ConA-stimulated cells to low doses of PKB inhibitor (MK-2206), suggesting control of expression of the two PFKFB isoenzymes by PKB. Incubation of thymocytes with ConA resulted in increased expression and phosphorylation of the translation factors eukaryotic initiation factor-4E-binding protein-1 (4E-BP1) and ribosomal protein S6 (rpS6). Treatment of ConA-stimulated thymocytes with PFK-2 inhibitor (3PO) or MK-2206 led to significant decreases in Fru-2,6-P 2 content, medium lactate accumulation and rates of cell proliferation and protein synthesis. These data were confirmed by using siRNA knockdown of PFKFB3, PFKFB4 and PKB α/β in the more easily transfectable Jurkat E6-1 cell line. The findings suggest that increased PFKFB3 and PFKFB4 expression, but not increased PFKFB3 Ser461 phosphorylation, plays a role in increasing glycolysis in mitogen-stimulated thymocytes and implicate PKB in the upregulation of PFKFB3 and PFKFB4. The results also support a role for Fru-2,6-P 2 in coupling glycolysis to cell proliferation and protein synthesis in this model. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis of (S)-(+)-decursin and its analogues as potent inhibitors of melanin formation in B16 murine melanoma cells.

PubMed

Lee, Kyeong; Lee, Jee-Hyun; Boovanahalli, Shanthaveerappa K; Choi, Yongseok; Choo, Soo-Jin; Yoo, Ick-dong; Kim, Dong Hee; Yun, Mi Young; Lee, Gye Won; Song, Gyu-Yong

2010-12-01

We report the synthesis of a novel series of highly potent melanin inhibitors which were obtained through structural modification of an anticancer compound S-(+)-decursinol. The in vitro inhibitory potencies of the newly synthesized compounds were evaluated against α-MSH induced melanin production in B16 murine melanoma cells. Among the compounds evaluated, compounds 2, 3, 6b, 7a, 7b, 8a and 8b emerged as highly potent inhibitors of melanin production. Besides, these compounds demonstrated significantly low cytotoxicity. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Inhibitor profiling of the Pseudomonas aeruginosa virulence factor LasB using N-alpha mercaptoamide template-based inhibitors.

PubMed

Cathcart, George R; Gilmore, Brendan F; Greer, Brett; Harriott, Pat; Walker, Brian

2009-11-01

We report on the synthesis and biological evaluation of a focussed library of N-alpha mercaptoamide containing dipeptides as inhibitors of the zinc metallopeptidase Pseudomonas aeruginosa elastase (LasB, EC 3.4.24.26). The aim of the study was to derive an inhibitor profile for LasB with regard to mapping the S'1 binding site of the enzyme. Consequently, a focussed library of 160 members has been synthesised, using standard Fmoc-solid phase methods (on a Rink-amide resin), in which a subset of amino acids including examples of those with basic (Lys, Arg), aromatic (Phe, Trp), large aliphatic (Val, Leu) and acidic (Asp, Glu) side-chains populated the P'2 position of the inhibitor sequence and all 20 natural amino acids were incorporated, in turn, at the P'1 position. The study has revealed a preference for aromatic and/or large aliphatic amino acids at P'1 and a distinct bias against acidic residues at P'2. Ten inhibitor sequences were discovered that exhibited sub to low micromolar Ki values.

Stress Granule-Inducing Eukaryotic Translation Initiation Factor 4A Inhibitors Block Influenza A Virus Replication

PubMed Central

Slaine, Patrick D.; Kleer, Mariel; Smith, Nathan K.; Khaperskyy, Denys A.

2017-01-01

Eukaryotic translation initiation factor 4A (eIF4A) is a helicase that facilitates assembly of the translation preinitiation complex by unwinding structured mRNA 5′ untranslated regions. Pateamine A (PatA) and silvestrol are natural products that disrupt eIF4A function and arrest translation, thereby triggering the formation of cytoplasmic aggregates of stalled preinitiation complexes known as stress granules (SGs). Here we examined the effects of eIF4A inhibition by PatA and silvestrol on influenza A virus (IAV) protein synthesis and replication in cell culture. Treatment of infected cells with either PatA or silvestrol at early times post-infection resulted in SG formation, arrest of viral protein synthesis and failure to replicate the viral genome. PatA, which irreversibly binds to eIF4A, sustained long-term blockade of IAV replication following drug withdrawal, and inhibited IAV replication at concentrations that had minimal cytotoxicity. By contrast, the antiviral effects of silvestrol were fully reversible; drug withdrawal caused rapid SG dissolution and resumption of viral protein synthesis. IAV inhibition by silvestrol was invariably associated with cytotoxicity. PatA blocked replication of genetically divergent IAV strains, suggesting common dependence on host eIF4A activity. This study demonstrates that the core host protein synthesis machinery can be targeted to block viral replication. PMID:29258238

Biocatalytic ammonolysis of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester: preparation of an intermediate to the dipeptidyl peptidase IV inhibitor Saxagliptin.

PubMed

Gill, Iqbal; Patel, Ramesh

2006-02-01

An efficient biocatalytic method has been developed for the conversion of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester (1) into the corresponding amide (5S)-5-aminocarbonyl-4,5-dihydro-1H-pyrrole-1-carboxylic acid, 1-(1,1-dimethylethyl)ester (2), which is a critical intermediate in the synthesis of the dipeptidyl peptidase IV (DPP4) inhibitor Saxagliptin (3). Candida antartica lipase B mediates ammonolysis of the ester with ammonium carbamate as ammonia donor to yield up to 71% of the amide. The inclusion of Ascarite and calcium chloride as adsorbents for carbon dioxide and ethanol byproducts, respectively, increases the yield to 98%, thereby offering an efficient and practical alternative to chemical routes which yield 57-64%.

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

PubMed

Aitken, H; Poyser, N L

2001-01-01

The outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)were similar from the day 22 guinea-pig placenta and sub-placenta in culture, except for PGE2 output from the sub-placenta which was lower. Between days 22 and 29 of pregnancy, the outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)during the initial 2 h culture period increased 6.9-, 1.1- and 3.2-fold, respectively, from the placenta, and 2.1-, 1.4- and 2.2-fold, respectively, from the sub-placenta. Therefore, there was a relatively specific increase in PGF(2 alpha)production by the guinea-pig placenta between days 22 and 29 of pregnancy. The output of PGFM from the cultured placenta also increased between days 22 and 29, indicating that the increase in PGF(2 alpha)output was due to increased synthesis rather than to decreased metabolism. By comparing the amounts of prostaglandins produced by tissue homogenates during a 1 h incubation period, it appears that there is approximately a 2-fold increase in the amount of prostaglandin H synthase (PGHS) present in the guinea-pig placenta between days 22 and 29. NS-398 (a specific inhibitor of PGHS-2) and indomethacin (an inhibitor of both PGHS-1 and PGHS-2) both inhibited prostaglandin production by homogenates of day 22 and day 29 placenta. Indomethacin was more effective than NS-398, except for their actions on PGF(2 alpha)production by the day 29 placenta where indomethacin and NS-398 were equiactive. Indomethacin and NS-398 were both very effective at inhibiting the outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)from the day 22 and day 29 placenta and sub-placenta in culture, indicating that prostaglandin production by the guinea-pig placenta and sub-placenta in culture is largely dependent upon the activity of PGHS-2. The high production of PGF(2 alpha)by the day 29 placenta is not dependent on the continual synthesis of fresh protein(s), as inhibitors of protein synthesis did not reduce PGF(2 alpha)output from the day 29 guinea-pig placenta in culture. Copyright 2001 Harcourt Publishers Ltd.

Synergistic anticancer effects of combined γ-tocotrienol and celecoxib treatment are associated with suppression in Akt and NFκB signaling

PubMed Central

Shirode, Amit B.; Sylvester, Paul W.

2009-01-01

The selective cyclooxygenase (COX)-2 inhibitor, celecoxib, and the vitamin E isoform, γ-tocotrienol, both display potent anticancer activity. However, high dose clinical use of selective COX-2 inhibitors has been limited by gastrointestinal and cardiovascular toxicity, whereas limited absorption and transport of γ-tocotrienol by the body has made it difficult to obtain and sustain therapeutic levels in the blood and target tissues. Studies were conducted to characterize the synergistic anticancer antiproliferative effects of combined low dose celecoxib and γ-tocotrienol treatment on mammary tumor cells in culture. The highly malignant mouse +SA mammary epithelial cells were maintained in culture on serum-free defined control or treatment media. Treatment effects on COX-1, COX-2, Akt, NFκB and prostaglandin E2 (PGE2) synthesis was assessed following a 3- or 4-day culture period. Treatment with 3–4 μM γ-tocotrienol or 7.5–10 μM celecoxib alone significantly inhibited +SA cell growth in a dose-responsive manner. However, combined treatment with subeffective doses of γ-tocotrienol (0.25 μM) and celecoxib (2.5 μM) resulted in a synergistic antiproliferative effect, as determined by isobologram analysis, and this growth inhibitor effect was associated with a reduction in PGE2 synthesis, and decrease in COX-2, phospho-Akt (active), and phospho-NFκB (active) levels. These results demonstrate that the synergistic anticancer effects of combined celecoxib and γ-tocotrienol therapy are mediated by COX-2 dependent and independent mechanisms. These findings also suggest that combination therapy with these agents may provide enhanced therapeutic response in breast cancer patients, while avoiding the toxicity associated with high-dose COX-2 inhibitor monotherapy. PMID:19954924

Synthesis, biological evaluation and docking analysis of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones as potential cyclooxygenase-2 (COX-2) inhibitors.

PubMed

Grover, Jagdeep; Kumar, Vivek; Sobhia, M Elizabeth; Jachak, Sanjay M

2014-10-01

As a part of our continued efforts to discover new COX inhibitors, a series of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones were synthesized and evaluated for in vitro COX inhibitory potential. Within this series, seven compounds (3a-d, 3h, 3k and 3q) were identified as potential and selective COX-2 inhibitors (COX-2 IC50's in 1.79-4.35μM range; COX-2 selectivity index (SI)=6.8-16.7 range). Compound 3b emerged as most potent (COX-2 IC50=1.79μM; COX-1 IC50 >30μM) and selective COX-2 inhibitor (SI >16.7). Further, compound 3b displayed superior anti-inflammatory activity (59.86% inhibition of edema at 5h) in comparison to celecoxib (51.44% inhibition of edema at 5h) in carrageenan-induced rat paw edema assay. Structure-activity relationship studies suggested that N-phenyl ring substituted with p-CF3 substituent (3b, 3k and 3q) leads to more selective inhibition of COX-2. To corroborate obtained experimental biological data, molecular docking study was carried out which revealed that compound 3b showed stronger binding interaction with COX-2 as compared to COX-1. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preparation of tyrosinase inhibitors and antibrowning agents using green technology.

PubMed

Dong, Xue; Zhang, Yinan; He, Jia-Liang; Zhang, Shuang; Zeng, Mao-Mao; Chen, Jie; Zheng, Zong-Ping

2016-04-15

Chalcones and their derivatives have attracted great interests in recent years for their comprehensive biological activities. In this study, 2,4,2',4'-tetrahydroxychalcone and its two derivatives, 1,3,5-tris-(2,4-dihydroxy-phenyl)pentane-1,5-dione (new compound) and 7,2',4'-trihydroxyflavanone, were synthesized through one-pot green procedure catalyzed by boric acid in polyethylene glycol 400. Their structures were identified by ESI-MS and NMR spectral. Tyrosinase inhibitory activity and antibrowning test results showed that compounds 1-3 exhibited strong tyrosinase inhibitory activities and significant antibrowning effects on the fresh-cut lotus root slices at room temperature in 48 h. Among them, 0.01% 1,3,5-tris-(2,4-dihydroxy-phenyl)pentane-1,5-dione combined with 0.5% VC showed the best antibrowning ability. In brief, this study offers a protocol for one-pot green synthesis of high efficiency tyrosinase inhibitors which may be suitable as antibrowning agents for fresh-cut vegetables. More important, this study developed a new type of 1,5-dione derivative which may serve as new lead structures for novel tyrosinase inhibitors discovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design, synthesis and molecular modeling of aloe-emodin derivatives as potent xanthine oxidase inhibitors.

PubMed

Shi, Da-Hua; Huang, Wei; Li, Chao; Liu, Yu-Wei; Wang, Shi-Fan

2014-03-21

A series of aloe-emodin derivatives were synthesized and evaluated as xanthine oxidase inhibitors. Among them, four aloe-emodin derivatives showed significant inhibitory activities against xanthine oxidase. The compound 4,5-dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carbaldehyde (A1) possessed the best xanthine oxidase inhibitory activity with IC50 of 2.79 μM. Lineweaver-Burk plot analysis revealed that A1 acted as a mixed-type inhibitor for xanthine oxidase. The docking study revealed that the molecule A1 had strong interactions with the active site of xanthine oxidase and this result was in agreement with kinetic study. Consequently, compound A1 is a new-type candidate for further development for the treatment of gout. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Total Synthesis and Stereochemical Assignment of Nostosin B

PubMed Central

Wang, Xiaoji; Feng, Junmin; Xu, Zhengshuang; Ye, Tao; Meng, Yi; Zhang, Zhiyu

2017-01-01

Nostosins A and B were isolated from a hydrophilic extract of Nostoc sp. strain from Iran, which exhibits excellent trypsin inhibitory activity. Nostosin A was the most potent natural tripeptide aldehyde as trypsin inhibitor up to now. Both r- and s-2-hydroxy-4-(4-hydroxy-phenyl)butanoic acid (Hhpba) were prepared and incorporated into the total synthesis of nostosin B, respectively. Careful comparison of the NMR spectra and optical rotation data of synthetic nostosin B (1a and 1b) with the natural product led to the unambiguous identification of the r-configuration of the Hhpba fragment, which was further confirmed by co-injection with the authentic sample on HPLC using both reversed phase column and the chiral AD-RH column. PMID:28264450

FR258900, a novel glycogen phosphorylase inhibitor isolated from Fungus No. 138354. I. Taxonomy, fermentation, isolation and biological activities.

PubMed

Furukawa, Shigetada; Tsurumi, Yasuhisa; Murakami, Kana; Nakanishi, Tomoko; Ohsumi, Keisuke; Hashimoto, Michizane; Nishikawa, Motoaki; Takase, Shigehiro; Nakayama, Osamu; Hino, Motohiro

2005-08-01

FR258900 is a novel glycogen synthesis activator produced by Fungus No. 138354. This compound was isolated from the culture broth by solvent extraction and reverse-phase column chromatography. FR258900 stimulated glycogen synthesis and glycogen synthase activity in primary rat hepatocytes. FR258900 exhibited a potent inhibitory effect on the activity of liver glycogen phosphorylase, suggesting that this compound may activate hepatic glycogen synthesis via glycogen phosphorylase inhibition. Thus, this glycogen phosphorylase inhibitor may be useful in the treatment of postprandial hyperglycemia in type 2 diabetes.

Design and Synthesis of a Library of Lead-Like 2,4-Bisheterocyclic Substituted Thiophenes as Selective Dyrk/Clk Inhibitors

PubMed Central

Schmitt, Christian; Kail, Dagmar; Mariano, Marica; Empting, Martin; Weber, Nadja; Paul, Tamara; Hartmann, Rolf W.; Engel, Matthias

2014-01-01

The Dyrk family of protein kinases is implicated in the pathogenesis of several diseases, including cancer and neurodegeneration. Pharmacological inhibitors were mainly described for Dyrk1A so far, but in fewer cases for Dyrk1B, Dyrk2 or other isoforms. Herein, we report the development and optimization of 2,4-bisheterocyclic substituted thiophenes as a novel class of Dyrk inhibitors. The optimized hit compounds displayed favorable pharmacokinetic properties and high ligand efficiencies, and inhibited Dyrk1B in intact cells. In a larger selectivity screen, only Clk1 and Clk4 were identified as additional targets of compound 48, but no other kinases frequently reported as off-targets. Interestingly, Dyrk1A is implicated in the regulation of alternative splicing, a function shared with Clk1/Clk4; thus, some of the dual inhibitors might be useful as efficient splicing modulators. A further compound (29) inhibited Dyrk1A and 1B with an IC50 of 130 nM, showing a moderate selectivity over Dyrk2. Since penetration of the central nervous system (CNS) seems possible based on the physicochemical properties, this compound might serve as a lead for the development of potential therapeutic agents against glioblastoma. Furthermore, an inhibitor selective for Dyrk2 (24) was also identified, which might be are suitable as a pharmacological tool to dissect Dyrk2 isoform–mediated functions. PMID:24676346

[The specific enzyme inhibitors for potential therapeutic use].

PubMed

Bretner, Maria

2015-01-01

Therapy for hepatitis C virus (HCV) initially consisted on administering ribavirin - having a broad spectrum of action - and pegylated interferon, and was only effective in 40-50% of patients. Appropriate was to find effective inhibitors of viral replication e.g. by inhibition of a viral enzyme, NTPase/helicase required in the process of translation and RNA replication of the HCV. We developed methods of synthesis of many compounds belonging to different groups - derivatives of nucleosides, benzotriazole, benzimidazole, tropolone and epirubicine. Some of the derivatives inhibit HCV helicase activity at low concentrations and reduces replication of the viral RNA in subgenomic replicon system. In the process of HCV replication casein kinase CK2 plays an important role. It regulates the level of phosphorylation of HCV protein NS5A, which affects the production of infectious virions of HCV. Effective and selective inhibitors of kinase CK2 could be of use in the treatment of HCV in combination with other drugs. CK2 kinase phosphorylates approximately 300 proteins that affect the growth, differentiation, proliferation or apoptosis. Elevated CK2 kinase activity has been observed in several types of cancer and other diseases, therefore, inhibitors of this enzyme are potential therapeutic importance, particularly for anti-cancer treatment. Research carried out in collaboration with prof. Shugar led to the synthesis of one of the most selective inhibitors of this enzyme which is 4,5,6,7-tetrabromo-1H-benzotriazole, used for the study of the role of kinase CK2 in a number of metabolic processes in tumor cells.

Chemoprevention of Prostate Cancer by Phenethyl Isothiocyanate

DTIC Science & Technology

2007-03-01

AD cells were exposed to PEITC, protein synthesis inhibitor cycloheximide (CHX), or proteasome inhibitor MG-132 alone, or to the combination of...The results indicated that down-regulation of Sp1 may require protein synthesis for a proteasome activity, thereby enhancing Sp1 protein degradation...carcinogen N- methyl-N- nitrosourea (MNU) for the formation of prostate tumors. The experimental group of rats was provided with PEITC, to evaluate the

Inhibition of Fatty Acid Synthesis Induces Apoptosis of Human Pancreatic Cancer Cells.

PubMed

Nishi, Koji; Suzuki, Kenta; Sawamoto, Junpei; Tokizawa, Yuma; Iwase, Yumiko; Yumita, Nagahiko; Ikeda, Toshihiko

2016-09-01

Cancer cells tend to have a high requirement for lipids, including fatty acids, cholesterol and triglyceride, because of their rapid proliferative rate compared to normal cells. In this study, we investigated the effects of inhibition of lipid synthesis on the proliferation and viability of human pancreatic cancer cells. Of the inhibitors of lipid synthesis that were tested, 5-(tetradecyloxy)-2-furoic acid (TOFA), which is an inhibitor of acetyl-CoA carboxylase, and the fatty acid synthase (FAS) inhibitors cerulenin and irgasan, significantly suppressed the proliferation of MiaPaCa-2 and AsPC-1 cells. Treatment of MiaPaCa-2 cells with these inhibitors significantly increased the number of apoptotic cells. In addition, TOFA increased caspase-3 activity and induced cleavage of poly (ADP-ribose) polymerase in MiaPaCa-2 cells. Moreover, addition of palmitate to MiaPaCa-2 cells treated with TOFA rescued cells from apoptotic cell death. These results suggest that TOFA induces apoptosis via depletion of fatty acids and that, among the various aspects of lipid metabolism, inhibition of fatty acid synthesis may be a notable target for the treatment of human pancreatic cancer cells. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Three-component, one-pot synthesis of anthranilamide Schiff bases bearing 4-aminoquinoline moiety as Mycobacterium tuberculosis gyrase inhibitors.

PubMed

Salve, Preeti S; Alegaon, Shankar G; Sriram, Dharmarajan

2017-04-15

An efficient three-component, one-pot protocol is described for the synthesis of biologically interesting 2-(benzylideneamino)-N-(7-chloroquinolin-4-yl)benzohydrazide derivatives from isatoic anhydride, 7-chloro-4-hydrazinylquinoline and aromatic and/or hetero aromatic aldehydes under catalyst free condensation by using water as reaction media. All synthesized compounds were evaluated for their antimycobacterial activity against Mycobacterium tuberculosis (MTB) and cytotoxicity activity against normal VERO cell lines. The synthesized compounds exhibited minimum inhibitory concentration (MIC) ranging from 0.78 to 25μM. Among the tested compounds 4c, 4o, 4r, and 4u exhibited promising inhibitory activity (MIC=3.12μM). Compounds 4h and 4i stand out, showing MIC values of 0.78 and 1.56μM respectively. Both compounds were further screened for their Mycobacterium tuberculosis DNA gyrase inhibitory assay which suggested that these compounds have a great potential for further optimization and development as antitubercular agents. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Arabidopsis COBRA Protein Facilitates Cellulose Crystallization at the Plasma Membrane*

PubMed Central

Sorek, Nadav; Sorek, Hagit; Kijac, Aleksandra; Szemenyei, Heidi J.; Bauer, Stefan; Hématy, Kian; Wemmer, David E.; Somerville, Chris R.

2014-01-01

Mutations in the Arabidopsis COBRA gene lead to defects in cellulose synthesis but the function of COBRA is unknown. Here we present evidence that COBRA localizes to discrete particles in the plasma membrane and is sensitive to inhibitors of cellulose synthesis, suggesting that COBRA and the cellulose synthase complex reside in close proximity on the plasma membrane. Live-cell imaging of cellulose synthesis indicated that, once initiated, cellulose synthesis appeared to proceed normally in the cobra mutant. Using isothermal calorimetry, COBRA was found to bind individual β1–4-linked glucan chains with a KD of 3.2 μm. Competition assays suggests that COBRA binds individual β1–4-linked glucan chains with higher affinity than crystalline cellulose. Solid-state nuclear magnetic resonance studies of the cell wall of the cobra mutant also indicated that, in addition to decreases in cellulose amount, the properties of the cellulose fibrils and other cell wall polymers differed from wild type by being less crystalline and having an increased number of reducing ends. We interpret the available evidence as suggesting that COBRA facilitates cellulose crystallization from the emerging β1–4-glucan chains by acting as a “polysaccharide chaperone.” PMID:25331944

BRD4 assists elongation of both coding and enhancer RNAs guided by histone acetylation

PubMed Central

Kanno, Tomohiko; Kanno, Yuka; LeRoy, Gary; Campos, Eric; Sun, Hong-Wei; Brooks, Stephen R; Vahedi, Golnaz; Heightman, Tom D; Garcia, Benjamin A; Reinberg, Danny; Siebenlist, Ulrich; O’Shea, John J; Ozato, Keiko

2016-01-01

Small-molecule BET inhibitors interfere with the epigenetic interactions between acetylated histones and the bromodomains of the BET family proteins, including BRD4, and they potently inhibit growth of malignant cells by targeting cancer-promoting genes. BRD4 interacts with the pause-release factor P-TEFb, and has been proposed to release Pol II from promoter-proximal pausing. We show that BRD4 occupied widespread genomic regions in mouse cells, and directly stimulated elongation of both protein-coding transcripts and non-coding enhancer RNAs (eRNAs), dependent on the function of bromodomains. BRD4 interacted physically with elongating Pol II complexes, and assisted Pol II progression through hyper-acetylated nucleosomes by interacting with acetylated histones via bromodomains. On active enhancers, the BET inhibitor JQ1 antagonized BRD4-associated eRNA synthesis. Thus, BRD4 is involved in multiple steps of the transcription hierarchy, primarily by assisting transcript elongation both at enhancers and on gene bodies. PMID:25383670

[Simultaneous analysis of aromatic aldehydes and coumarins with high pressure liquid chromatography. Application to wines and brandies stored in oak barrels].

PubMed

Salagoity-Auguste, M H; Tricard, C; Sudraud, P

1987-04-17

Aromatic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and coumarins (esculetin, umbelliferone, scopoletin and methylumbelliferone) are natural wood compounds. Storage of wines and brandies in oak barrels increases notably aldehydes and coumarins (particularly scopoletin) concentrations. These compounds were separated by high-performance liquid chromatography, on hydrocarbon bonded reversed-phase packings, with a water-acetonitrile elution gradient. They were first extracted from wines and brandies by diethyl ether and then injected on chromatographic column. A double detection was used to determine simultaneously aromatic aldehydes and coumarins by UV absorption and fluorescence respectively.

Discovery of Brigatinib (AP26113), a Phosphine Oxide-Containing, Potent, Orally Active Inhibitor of Anaplastic Lymphoma Kinase.

PubMed

Huang, Wei-Sheng; Liu, Shuangying; Zou, Dong; Thomas, Mathew; Wang, Yihan; Zhou, Tianjun; Romero, Jan; Kohlmann, Anna; Li, Feng; Qi, Jiwei; Cai, Lisi; Dwight, Timothy A; Xu, Yongjin; Xu, Rongsong; Dodd, Rory; Toms, Angela; Parillon, Lois; Lu, Xiaohui; Anjum, Rana; Zhang, Sen; Wang, Frank; Keats, Jeffrey; Wardwell, Scott D; Ning, Yaoyu; Xu, Qihong; Moran, Lauren E; Mohemmad, Qurish K; Jang, Hyun Gyung; Clackson, Tim; Narasimhan, Narayana I; Rivera, Victor M; Zhu, Xiaotian; Dalgarno, David; Shakespeare, William C

2016-05-26

In the treatment of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase positive (ALK+) non-small-cell lung cancer (NSCLC), secondary mutations within the ALK kinase domain have emerged as a major resistance mechanism to both first- and second-generation ALK inhibitors. This report describes the design and synthesis of a series of 2,4-diarylaminopyrimidine-based potent and selective ALK inhibitors culminating in identification of the investigational clinical candidate brigatinib. A unique structural feature of brigatinib is a phosphine oxide, an overlooked but novel hydrogen-bond acceptor that drives potency and selectivity in addition to favorable ADME properties. Brigatinib displayed low nanomolar IC50s against native ALK and all tested clinically relevant ALK mutants in both enzyme-based biochemical and cell-based viability assays and demonstrated efficacy in multiple ALK+ xenografts in mice, including Karpas-299 (anaplastic large-cell lymphomas [ALCL]) and H3122 (NSCLC). Brigatinib represents the most clinically advanced phosphine oxide-containing drug candidate to date and is currently being evaluated in a global phase 2 registration trial.

Development of Thioaryl-Based Matrix Metalloproteinase-12 Inhibitors with Alternative Zinc-Binding Groups: Synthesis, Potentiometric, NMR, and Crystallographic Studies.

PubMed

Nuti, Elisa; Cuffaro, Doretta; Bernardini, Elisa; Camodeca, Caterina; Panelli, Laura; Chaves, Sílvia; Ciccone, Lidia; Tepshi, Livia; Vera, Laura; Orlandini, Elisabetta; Nencetti, Susanna; Stura, Enrico A; Santos, M Amélia; Dive, Vincent; Rossello, Armando

2018-05-24

Matrix metalloproteinase-12 (MMP-12) selective inhibitors could play a role in the treatment of lung inflammatory and cardiovascular diseases. In the present study, the previously reported 4-methoxybiphenylsulfonyl hydroxamate and carboxylate based inhibitors (1b and 2b) were modified to enhance their selectivity for MMP-12. In the newly synthesized thioaryl derivatives, the nature of the zinc binding group (ZBG) and the sulfur oxidation state were changed. Biological assays carried out in vitro on human MMPs with the resulting compounds led to identification of a sulfide, 4a, bearing an N-1-hydroxypiperidine-2,6-dione (HPD) group as new ZBG. Compound 4a is a promising hit compound since it displayed a nanomolar affinity for MMP-12 with a marked selectivity over MMP-9, MMP-1, and MMP-14. Solution complexation studies with Zn 2+ were performed to characterize the chelating abilities of the new compounds and confirmed the bidentate binding mode of HPD derivatives. X-ray crystallography studies using MMP-12 and MMP-9 catalytic domains were carried out to rationalize the biological results.

Synthesis, molecular modeling and biological evaluation of PSB as targeted antibiotics.

PubMed

Cheng, Kui; Zheng, Qing-Zhong; Hou, Jin; Zhou, Yang; Liu, Chang-Hong; Zhao, Jing; Zhu, Hai-Liang

2010-04-01

We described here the design, synthesis, molecular modeling, and biological evaluation of a series of peptide and Schiff bases (PSB) small molecules, inhibitors of Escherichia coli beta-Ketoacyl-acyl carrier protein synthase III (ecKAS III). The initial lead compound was reported by us previously, we continued to carry out structure-activity relationship studies and optimize the lead structure to potent inhibitors in this research. The results demonstrated that both N-(2-(3,5-dichloro-2-hydroxybenzylideneamino)propyl)-2-hydroxybenzamide (1f) and 2-hydroxy-N-(2-(2-hydroxy-5-iodobenzylideneamino)propyl)-4-methylbenzamide (3e) posses good ecKAS III inhibitory activity and well binding affinities by bonding Gly152/Gly209 of ecKAS III and fit into the mouth of the substrate tunnel, and can be as potential antibiotics agent, displaying minimal inhibitory concentration values in the range 0.20-3.13microg/mL and 0.39-3.13microg/mL against various bacteria. Copyright 2010 Elsevier Ltd. All rights reserved.

Selective Effects of Purine and Pyrimidine Analogues and of Respiratory Inhibitors on Perithecial Development and Branching in Sordaria 12

PubMed Central

Lindenmayer, Aristid; Schoen, Howard F.

1967-01-01

The initiation of perithecia in the homothallic ascomycete Sordaria fimicola was completely suppressed, without seriously inhibiting vegetative growth, by growing the fungus on an agar medium containing one of the following additions: 1) 1 μm 5-fluorouracil, 2) 10 to 100 μm 6-azauracil, 8-azaguanine or 8-azaadenine, 3) 50 to 500 μm cyanide or azide, 4) 5% (w/v) casein hydrolysate. In contrast to the selective activity of the analogues of 3 RNA bases, whose inhibition could be reversed by the appropriate normal bases only, none of the analogues of thymine were active, neither were the thio-derivatives of RNA bases. Other inhibitors of RNA and protein synthesis, like actinomycin D, puromycin and cycloheximide, were also without selective activity, although the last of these inhibited perithecial maturation at 0.1 μm concentration but not initiation. Amino acid analogues were inactive, as were the metabolic inhibitors thiourea, 2,4-dinitrophenol and fluoride. The compounds which inhibited the formation of perithecia also lowered the branching frequency of leading hyphae, but not their linear growth rates. Consequently, the branch densities were diminished in their presence. Hypotheses to account for these findings are discussed in terms of inhibition of growth in general, of the synthesis of some specific messenger RNAs, and of RNA-mediated transport across membranes, the last of which seeming the most fruitful for further work. PMID:16656614

Zirconium catalyzed synthesis of 2-arylidene Indan-1,3-diones and evaluation of their inhibitory activity against NS2B-NS3 WNV protease.

PubMed

Oliveira, Ana Flávia C da S; de Souza, Ana Paula M; de Oliveira, André S; da Silva, Milene L; de Oliveira, Fabrício M; Santos, Edjon G; da Silva, Ítalo Esposti P; Ferreira, Rafaela S; Villela, Filipe S; Martins, Felipe T; Leal, Daniel H S; Vaz, Boniek G; Teixeira, Róbson R; de Paula, Sergio O

2018-04-10

A simple and efficient Knoevenagel procedure for the synthesis of 2-arylidene indan-1,3-diones is herein reported. These compounds were prepared via ZrOCl2·8H2O catalyzed reactions of indan-1,3-dione with several aromatic aldehydes and using water as the solvent. The 2-arylidene indan-1,3-diones were obtained with 53%-95% yield within 10-45 min. The synthesized compounds were evaluated as inhibitors of the NS2B-NS3 protease of West Nile Virus (WNV). It was found that hydroxylated derivatives impaired enzyme activity with varying degrees of effectiveness. The most active hydroxylated derivatives, namely 2-(4-hydroxybenzylidene)-1H-indene-1,3(2H)-dione (14) and 2-(3,4-dihydroxybenzylidene)-1H-indene-1,3(2H)-dione (17), were characterized as noncompetitive enzymes inhibitors, with IC 50 values of 11 μmol L -1 and 3 μmol L -1 , respectively. Docking and electrostatic potential surfaces investigations provided insight on the possible binding mode of the most active compounds within an allosteric site. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Design, synthesis and biological evaluations of N-Hydroxy thienopyrimidine-2,4-diones as inhibitors of HIV reverse transcriptase-associated RNase H.

PubMed

Kankanala, Jayakanth; Kirby, Karen A; Huber, Andrew D; Casey, Mary C; Wilson, Daniel J; Sarafianos, Stefan G; Wang, Zhengqiang

2017-12-01

Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) is the only HIV enzymatic function not targeted by current antiviral drugs. Although various chemotypes have been reported to inhibit HIV RNase H, few have shown significant antiviral activities. We report herein the design, synthesis and biological evaluation of a novel N-hydroxy thienopyrimidine-2,3-dione chemotype (11) which potently and selectively inhibited RNase H with considerable potency against HIV-1 in cell culture. Current structure-activity-relationship (SAR) identified analogue 11d as a nanomolar inhibitor of RNase H (IC 50  = 0.04 μM) with decent antiviral potency (EC 50  = 7.4 μM) and no cytotoxicity (CC 50  > 100 μM). In extended biochemical assays compound 11d did not inhibit RT polymerase (pol) while inhibiting integrase strand transfer (INST) with 53 fold lower potency (IC 50  = 2.1 μM) than RNase H inhibition. Crystallographic and molecular modeling studies confirmed the RNase H active site binding mode. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Synthesis, characterization and inhibitory activities of (4-N3[3,5-3H]Phe10)PKI(6-22)amide and its precursors: photoaffinity labeling peptides for the active site of cyclic AMP-dependent protein kinase.

PubMed

Katz, B M; Lundquist, L J; Walsh, D A; Glass, D B

1989-06-01

PKI(6-22)amide is a 17 residue peptide corresponding to the active portion of the heat-stable inhibitor of cAMP-dependent protein kinase. The peptide is a potent (Ki = 1.6 nM), competitive inhibitor of the enzyme. The photoreactive peptide analog (4-azidophenylalanine10)PKI(6-22)amide was synthesized in both its non-radiolabeled and tritiated forms by chemical modification of precursor peptides that were prepared by stepwise solid-phase synthesis. (4-Amino[3,5-3H]phenylalanine10)PKI(6-22)amide, the precursor for the radiolabeled arylazide peptide, was obtained by catalytic reduction of the corresponding peptide containing the 3,5-diiodo-4-aminophenylalanine residue at position 10. The purified PKI peptides were analyzed by HPLC, amino acid analysis, and u.v. spectra. In the dark, (4-azidophenylalanine10)PKI(6-22)amide inhibited the catalytic subunit of cAMP-dependent protein kinase with a Ki value of 2.8 nM. The photoreactivity of the arylazide peptide was demonstrated by time-dependent u.v. spectral changes on exposure to light. Photolysis of the catalytic subunit (4-azido[3,5-3H]phenylalanine10)PKI(6-22)amide complex resulted in specific covalent labeling of the enzyme. The data indicate that this peptide is a useful photoaffinity labeling reagent for the active site of the protein kinase.

Rational Design Synthesis and Evaluation of New Selective Inhibitors of Microbial Class II (Zinc Dependent) Fructose Bis-phosphate Aldolases

DOE Office of Scientific and Technical Information (OSTI.GOV)

R Daher; M Coincon; M Fonvielle

2011-12-31

We report the synthesis and biochemical evaluation of several selective inhibitors of class II (zinc dependent) fructose bis-phosphate aldolases (Fba). The products were designed as transition-state analogues of the catalyzed reaction, structurally related to the substrate fructose bis-phosphate (or sedoheptulose bis-phosphate) and based on an N-substituted hydroxamic acid, as a chelator of the zinc ion present in active site. The compounds synthesized were tested on class II Fbas from various pathogenic microorganisms and, by comparison, on a mammalian class I Fba. The best inhibitor shows Ki against class II Fbas from various pathogens in the nM range, with very highmore » selectivity (up to 105). Structural analyses of inhibitors in complex with aldolases rationalize and corroborate the enzymatic kinetics results. These inhibitors represent lead compounds for the preparation of new synthetic antibiotics, notably for tuberculosis prophylaxis.« less

Discovery of 8-Membered Ring Sulfonamides as Inhibitors of Oncogenic Mutant Isocitrate Dehydrogenase 1.

PubMed

Law, Jason M; Stark, Sebastian C; Liu, Ke; Liang, Norah E; Hussain, Mahmud M; Leiendecker, Matthias; Ito, Daisuke; Verho, Oscar; Stern, Andrew M; Johnston, Stephen E; Zhang, Yan-Ling; Dunn, Gavin P; Shamji, Alykhan F; Schreiber, Stuart L

2016-10-13

Evidence suggests that specific mutations of isocitrate dehydrogenases 1 and 2 (IDH1/2) are critical for the initiation and maintenance of certain tumor types and that inhibiting these mutant enzymes with small molecules may be therapeutically beneficial. In order to discover mutant allele-selective IDH1 inhibitors with chemical features distinct from existing probes, we screened a collection of small molecules derived from diversity-oriented synthesis. The assay identified compounds that inhibit the IDH1-R132H mutant allele commonly found in glioma. Here, we report the discovery of a potent (IC 50 = 50 nM) series of IDH1-R132H inhibitors having 8-membered ring sulfonamides as exemplified by the compound BRD2879. The inhibitors suppress ( R )-2-hydroxyglutarate production in cells without apparent toxicity. Although the solubility and pharmacokinetic properties of the specific inhibitor BRD2879 prevent its use in vivo , the scaffold presents a validated starting point for the synthesis of future IDH1-R132H inhibitors having improved pharmacological properties.

Suppression of c-Myc induces apoptosis via an AMPK/mTOR-dependent pathway by 4-O-methyl-ascochlorin in leukemia cells.

PubMed

Shin, Jae-Moon; Jeong, Yun-Jeong; Cho, Hyun-Ji; Magae, Junji; Bae, Young-Seuk; Chang, Young-Chae

2016-05-01

4-O-Methyl-ascochlorin (MAC) is a methylated derivative of the prenyl-phenol antibiotic ascochlorin, which was isolated from an incomplete fungus, Ascochyta viciae. Although the effects of MAC on apoptosis have been reported, the underlying mechanisms remain unknown. Here, we show that MAC promoted apoptotic cell death and downregulated c-Myc expression in K562 human leukemia cells. The effect of MAC on apoptosis was similar to that of 10058-F4 (a c-Myc inhibitor) or c-Myc siRNA, suggesting that the downregulation of c-Myc expression plays a role in the apoptotic effect of MAC. Further investigation showed that MAC downregulated c-Myc by inhibiting protein synthesis. MAC promoted the phosphorylation of AMP-activated protein kinase (AMPK) and inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and its target proteins, including p70S6 K and 4E-BP-1. Treatment of cells with AICAR (an AMPK activator), rapamycin (an mTOR inhibitor), or mTOR siRNA downregulated c-Myc expression and induced apoptosis to a similar extent to that of MAC. These results suggest that the effect of MAC on apoptosis induction in human leukemia cells is mediated by the suppression of c-Myc protein synthesis via an AMPK/mTOR-dependent mechanism.

Synthesis of carbon-14 and stable isotope labeled Avagacestat: a novel gamma secretase inhibitor for the treatment of Alzheimer's disease.

PubMed

Burrell, Richard C; Easter, John A; Cassidy, Michael P; Gillman, Kevin W; Olson, Richard E; Bonacorsi, Samuel J

2014-08-01

Bristol-Myers Squibb and others are developing drugs that target novel mechanisms to combat Alzheimer's disease. γ-Secretase inhibitors are one class of potential therapies that have received considerable attention. (R)-2-(4-Chloro-N-(2-fluoro-4-(1,2,4-oxadiazol-3-yl)benzyl)phenylsulfonamido)-5,5,5-trifluoropentanamide (Avagacestat) is a γ-secretase-inhibiting drug that has been investigated by Bristol-Myers Squibb in preclinical and clinical studies. An important step in the development process was the synthesis of a carbon-14-labeled analog for use in a human absorption, distribution, metabolism, and excretion study and a stable isotope labeled analog for use as a standard in bioanalytical assays to accurately quantify the concentration of the drug in biological samples. Carbon-14 labeled Avagacestat was synthesized in seven steps in a 33% overall yield from carbon-14 labeled potassium cyanide. A total of 5.95 mCi was prepared with a specific activity of 0.81 μCi/mg and a radiochemical purity of 99.9%. (13) C6 -Labeled Avagacestat was synthesized in three steps in a 15% overall yield from 4-chloro[(13) C6 ]aniline. A total of 585 mg was prepared with a ultraviolet purity of 99.9%. Copyright © 2014 John Wiley & Sons, Ltd.

A designed inhibitor of a CLC antiporter blocks function through a unique binding mode

PubMed Central

Howery, Andrew E.; Elvington, Shelley; Abraham, Sherwin J.; Choi, Kee-Hyun; Phillips, Sabrina; Ryan, Christopher M.; Sanford, R. Lea; Simpson-Dworschak, Sierra; Almqvist, Jonas; Tran, Kevin; Chew, Thomas A.; Zachariae, Ulrich; Andersen, Olaf S.; Whitelegge, Julian; Matulef, Kimberly; Du Bois, Justin; Maduke, Merritt C.

2012-01-01

SUMMARY The lack of small-molecule inhibitors for anion-selective transporters and channels has impeded our understanding of the complex mechanisms that underlie ion passage. The ubiquitous CLC “Chloride Channel” family represents a unique target for biophysical and biochemical studies because its distinctive protein fold supports both passive chloride channels and secondary-active chloride-proton transporters. Here, we describe the synthesis and characterization of the first specific small-molecule inhibitor directed against a CLC antiporter (ClC-ec1). This compound, 4,4′-octanamidostilbene-2,2′-disulfonate (OADS), inhibits ClC-ec1 with low micromolar affinity and has no specific effect on a CLC channel (ClC-1). Inhibition of ClC-ec1 occurs by binding to two distinct intracellular sites. The location of these sites and the lipid-dependence of inhibition suggest potential mechanisms of action. The discovery of this compound will empower research to elucidate differences between antiporter and channel mechanisms and to develop treatments for CLC-mediated disorders. PMID:23177200

Structure-Activity Relationships of a Novel Pyranopyridine Series of Gram-negative Bacterial Efflux Pump Inhibitors

PubMed Central

Nguyen, Son T.; Kwasny, Steven M.; Ding, Xiaoyuan; Cardinale, Steven C.; McCarthy, Courtney T.; Kim, Hong-Suk; Nikaido, Hiroshi; Peet, Norton P.; Williams, John D.; Bowlin, Terry L.; Opperman, Timothy J.

2015-01-01

Recently we described a novel pyranopyridine inhibitor (MBX2319) of RND-type efflux pumps of the Enterobacteriaceae. MBX2319 (3,3-dimethyl-5-cyano-8-morpholino-6-(phenethylthio)-3,4-dihydro-1H-pyrano[3,4-c]pyridine) is structurally distinct from other known Gram-negative efflux pump inhibitors (EPIs), such as 1-(1-naphthylmethyl)-piperazine (NMP), phenylalanylarginine-β-naphthylamide (PAβN), D13-9001, and the pyridopyrimidine derivatives. Here, we report the synthesis and biological evaluation of 60 new analogs of MBX2319 that were designed to probe the structure activity relationships (SARs) of the pyranopyridine scaffold. The results of these studies produced a molecular activity map of the scaffold, which identifies regions that are critical to efflux inhibitory activities and those that can be modified to improve potency, metabolic stability and solubility. Several compounds, such as 22d–f, 22i and 22k, are significantly more effective than MBX2319 at potentiating the antibacterial activity of levofloxacin and piperacillin against Escherichia coli. PMID:25818767

Design and synthesis of novel benzo[d]oxazol-2(3H)-one derivatives bearing 7-substituted-4-enthoxyquinoline moieties as c-Met kinase inhibitors.

PubMed

Lu, Dong; Shen, Aijun; Liu, Yang; Peng, Xia; Xing, Weiqiang; Ai, Jing; Geng, Meiyu; Hu, Youhong

2016-06-10

Analysis of the results of studies of docking 1 and 7a with c-Met kinase led to the identification of benzo[d]oxazol-2(3H)-one-quinolone derivatives as potential inhibitors of this enzyme. A molecular hybrid strategy, using a 4-ethoxy-7-substituted-quinoline core and a benzo[d]oxazol-2(3H)-one scaffold, was employed to design members of this family for study as inhibitors of the kinase and proliferation of EBC-1 cells. Most of the substances were found to display good to excellent c-Met kinase inhibitory activities. The results of a structure-activity relationship (SAR) study led to the discovery of benzo[d]oxazol-2(3H)-one-quinolone 13, which has IC50 values of 1 nM against c-Met kinase and 5 nM against proliferation of the EBC-1 cell line. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Development of inhibitors of the 2C-methyl-D-erythritol 4-phosphate (MEP) pathway enzymes as potential anti-infective agents.

PubMed

Masini, Tiziana; Hirsch, Anna K H

2014-12-11

Important pathogens such as Mycobacterium tuberculosis and Plasmodium falciparum, the causative agents of tuberculosis and malaria, respectively, and plants, utilize the 2C-methyl-D-erythritol 4-phosphate (MEP, 5) pathway for the biosynthesis of isopentenyl diphosphate (1) and dimethylallyl diphosphate (2), the universal precursors of isoprenoids, while humans exclusively utilize the alternative mevalonate pathway for the synthesis of 1 and 2. This distinct distribution, together with the fact that the MEP pathway is essential in numerous organisms, makes the enzymes of the MEP pathway attractive drug targets for the development of anti-infective agents and herbicides. Herein, we review the inhibitors reported over the past 2 years, in the context of the most important older developments and with a particular focus on the results obtained against enzymes of pathogenic organisms. We will also discuss new discoveries in terms of structural and mechanistic features, which can help to guide a rational development of inhibitors.

Discovery of Tetralones as Potent and Selective Inhibitors of Acyl-CoA:Diacylglycerol Acyltransferase 1.

PubMed

Cheung, Mui; Tangirala, Raghuram S; Bethi, Sridhar R; Joshi, Hemant V; Ariazi, Jennifer L; Tirunagaru, Vijaya G; Kumar, Sanjay

2018-02-08

Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) plays an important role in triglyceride synthesis and is a target of interest for the treatment of metabolic disorders. Herein we describe the structure-activity relationship of a novel tetralone series of DGAT1 inhibitors and our strategies for overcoming genotoxic liability of the anilines embedded in the chemical structures, leading to the discovery of a candidate compound, ( S )-2-(6-(5-(3-(3,4-difluorophenyl)ureido)pyrazin-2-yl)-1-oxo-2-(2,2,2-trifluoroethyl)-1,2,3,4-tetrahydronaphthalen-2-yl)acetic acid (GSK2973980A, 26d ). Compound 26d is a potent and selective DGAT1 inhibitor with excellent DMPK profiles and in vivo efficacy in a postprandial lipid excursion model in mice. Based on the overall biological and developability profiles and acceptable safety profiles in the 7-day toxicity studies in rats and dogs, compound 26d was selected as a candidate compound for further development in the treatment of metabolic disorders.

Recent developments in the synthesis of acetylcholinesterase inhibitors.

PubMed

Marco, José L; Carreiras, M Carmo

2003-09-01

The acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities of a series of pyrano[2,3-b]quinolines (2, 3), [1,8]naphthyridines (5, 6), 4-amino-2,3-diaryl-5,6,7,8-tetrahydrofuro[2,3-b]quinolines (11-13)/ 4-amino-6,7,8,9-tetrahydro-2,3-diphenyl-5H-cyclohepta[e]furo[2,3-b]pyridine (14), 4-amino-5,6,7,8-tetrahydro-2,3-diphenylthieno[2,3-b]quinoline (15)/ 4-amino-6,7,8,9-tetrahydro-2,3-diphenyl-5H-cyclohepta[e]thieno[2,3-b]pyridine (16) are described. These compounds are tacrine analogues that have been prepared from readily available polyfunctionalized ethyl [6-amino-5-cyano-4H-pyran]-3-carboxylates (9, 10), ethyl [6-amino-5-cyanopyridine]-3-carboxylates (7, 8), 2-amino-3-cyano-4,5-diarylfurans (17-19) and 2-amino-3-cyano-4,5-diphenylthiophene (20) via Friedländer condensation with selected ketones. These compounds are competitive and, in a few cases, non-competitive inhibitors for AChE, the most potent being compound (14), though three-fold less active than tacrine. The BuChE inhibitory activity is only significant in compounds 11 and 14, ten-fold less active than tacrine. Furthermore, the products 12 and 13 are selective and moderate AChE inhibitors.

Eosinophils as a novel cell source of prostaglandin D2: autocrine role in allergic inflammation

PubMed Central

Luna-Gomes, Tatiana; Magalhães, Kelly G; Mesquita-Santos, Fabio P.; Bakker-Abreu, Ilka; Samico, Rafaela F.; Molinaro, Raphael; Calheiros, Andrea S.; Diaz, Bruno L.; Bozza, Patrícia T.

2011-01-01

Prostaglandin (PG)D2 is a key mediator of allergic inflammatory diseases that is mainly synthesized by mast cells, which constitutively express high levels of the terminal enzyme involved in PGD2 synthesis, the hematopoietic PGD synthase (H-PGDS). Here, we investigated whether eosinophils are also able to synthesize, and therefore, supply biologically active PGD2. PGD2 synthesis was evaluated within human blood eosinophils, in vitro-differentiated mouse eosinophils, and eosinophils infiltrating inflammatory site of mouse allergic reaction. Biological function of eosinophil-derived PGD2 was studied by employing inhibitors of synthesis and activity. Constitutive expression of H-PGDS was found within non-stimulated human circulating eosinophils. Acute stimulation of human eosinophils with A23187 (0.1 – 5 μM) evoked PGD2 synthesis, which was located at the nuclear envelope and was inhibited by pre-treatment with HQL-79 (10 μM), a specific H-PGDS inhibitor. Pre-stimulation of human eosinophils with arachidonic acid (AA; 10 μM) or human eotaxin (6 nM) also enhanced HQL-79-sensitive PGD2 synthesis, which, by acting on membrane-expressed specific receptors (DP1 and DP2), displayed an autocrine/paracrine ability to trigger leukotriene (LT)C4 synthesis and lipid body biogenesis, hallmark events of eosinophil activation. In vitro-differentiated mouse eosinophils also synthesized paracrine/autocrine active PGD2 in response to AA stimulation. In vivo, at late time point of the allergic reaction, infiltrating eosinophils found at the inflammatory site appeared as an auxiliary PGD2-synthesizing cell population. Our findings reveal that eosinophils are indeed able to synthesize and secrete PGD2, hence representing during allergic inflammation an extra cell source of PGD2, which functions as an autocrine signal for eosinophil activation. PMID:22102725

40 CFR 725.421 - Introduced genetic material.

Code of Federal Regulations, 2010 CFR

2010-07-01

... elongation factor 2, leading to inhibition of protein synthesis in target respiratory, heart, kidney, and... protein synthesis inhibitor. Sequence Source Toxin Name Corynebacterium diphtheriae & C. ulcerans...

All-transglycolytic synthesis and characterization of sialyl(alpha2-3)galactosyl(beta1-4)xylosyl-p-nitrophenyl(beta1-), an oligosaccharide derivative related to glycosaminoglycan biosynthesis.

PubMed

Vetere, A; Ferro, S; Bosco, M; Cescutti, P; Paoletti, S

1997-08-01

Beta-D-Xylopyranosides, such as p-nitrophenyl-beta-D-xylopyranoside (Xyl-Np) or 4-methylumbelliferyl-beta-D-xylopyranoside (Xyl-MeUmb), when added to the culture medium of human skin fibroblasts have previously been shown to produce some Np- or MeUmb-oligosaccharides related to the regulation of glycosaminoglycan biosynthesis. Among these oligosaccharide derivatives, we synthesized the trisaccharide derivative NeuAc(alpha2-3)Gal(beta1-4)Xyl-Np(beta1- as a potential inhibitor of human skin fibroblast glycosaminoglycan biosynthesis. This synthesis was achieved by sequential use of transglycosylating activities of Escherichia coli beta-galactosidase and Trypanosoma cruzi trans-sialidase. The structure of the oligosaccharide obtained was determined by HPLC, ion-spray mass spectrometry, and NMR.

Studies on the neuroprotective action of kynurenine mono-oxygenase inhibitors in post-ischemic brain damage.

PubMed

Moroni, Flavio; Carpenedo, Raffaella; Cozzi, Andrea; Meli, Elena; Chiarugi, Alberto; Pellegrini-Giampietro, Domenico E

2003-01-01

Kynurenine 3-mono-oxygenase (KMO) inhibitors facilitate kynurenic acid (KYNA) neosynthesis and reduce the formation of 3OH-kynurenine (3-HK) and quinolinic acid (QUIN). They also attenuate post-ischemic brain damage and decrease glutamate (Glu) content in brain extracellular spaces. To investigate KMO mechanism(s) of neuroprotection, we performed experiments in gerbils subjected to bilateral carotid occlusion and in organotypic rat hippocampal slice cultures exposed to oxygen and glucose deprivation (OGD). In gerbils, direct application of KYNA (100 nM, through reverse microdialysis in the hippocampus) completely prevented the increase in Glu output induced by transient (5 min) occlusion of the carotids. In rat hippocampal slices exposed for 30 min to OGD, KMO inhibitors (m-nitrobenzoyl)-alanine (mNBA, 30-100 microM) or 3,4-dimethoxy-[-N-4-(nitrophenyl)thiazol-2yl]-benzenesulfonamide (Ro 61-8048, 1-10 microM) reduced post-ischemic neuronal death and increased KYNA concentrations in the incubation medium. KYNA may antagonize glycineb or alpha7 nicotinic acetylcholine receptors but the concentrations in the incubation medium never reached values that could efficiently antagonize receptor function. On the contrary, 3-HK (1-10 microM) added to slices exposed to OGD in the presence of KMO inhibitors completely prevented the neuroprotective effects of the inhibitors. Our findings suggest that KMO inhibitors reduce OGD-induced pyramidal cell death by decreasing 3-HK (and possibly QUIN) synthesis.

Discovery of novel BTK inhibitors with carboxylic acids.

PubMed

Gao, Xiaolei; Wang, James; Liu, Jian; Guiadeen, Deodial; Krikorian, Arto; Boga, Sobhana Babu; Alhassan, Abdul-Basit; Selyutin, Oleg; Yu, Wensheng; Yu, Younong; Anand, Rajan; Liu, Shilan; Yang, Chundao; Wu, Hao; Cai, Jiaqiang; Cooper, Alan; Zhu, Hugh; Maloney, Kevin; Gao, Ying-Duo; Fischmann, Thierry O; Presland, Jeremy; Mansueto, My; Xu, Zangwei; Leccese, Erica; Zhang-Hoover, Jie; Knemeyer, Ian; Garlisi, Charles G; Bays, Nathan; Stivers, Peter; Brandish, Philip E; Hicks, Alexandra; Kim, Ronald; Kozlowski, Joeseph A

2017-03-15

We report the design and synthesis of a series of novel Bruton's Tyrosine Kinase (BTK) inhibitors with a carboxylic acid moiety in the ribose pocket. This series of compounds has demonstrated much improved off-target selectivities including adenosine uptake (AdU) inhibition compared to the piperidine amide series. Optimization of the initial lead compound 4 based on BTK enzyme inhibition, and human peripheral blood mononuclear cell (hPBMC) and human whole blood (hWB) activity led to the discovery of compound 40, with potent BTK inhibition, reduced off target activities, as well as favorable pharmacokinetic profile in both rat and dog. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and preliminary biological evaluation of potent and selective 2-(3-alkoxy-1-azetidinyl) quinolines as novel PDE10A inhibitors with improved solubility.

PubMed

Rzasa, Robert M; Frohn, Michael J; Andrews, Kristin L; Chmait, Samer; Chen, Ning; Clarine, Jeffrey G; Davis, Carl; Eastwood, Heather A; Horne, Daniel B; Hu, Essa; Jones, Adrie D; Kaller, Matthew R; Kunz, Roxanne K; Miller, Silke; Monenschein, Holger; Nguyen, Thomas; Pickrell, Alexander J; Porter, Amy; Reichelt, Andreas; Zhao, Xiaoning; Treanor, James J S; Allen, Jennifer R

2014-12-01

We report the discovery of a novel series of 2-(3-alkoxy-1-azetidinyl) quinolines as potent and selective PDE10A inhibitors. Structure-activity studies improved the solubility (pH 7.4) and maintained high PDE10A activity compared to initial lead compound 3, with select compounds demonstrating good oral bioavailability. X-ray crystallographic studies revealed two distinct binding modes to the catalytic site of the PDE10A enzyme. An ex vivo receptor occupancy assay in rats demonstrated that this series of compounds covered the target within the striatum.

Identification of a new class of potent Cdc7 inhibitors designed by putative pharmacophore model: Synthesis and biological evaluation of 2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-ones.

PubMed

Kurasawa, Osamu; Oguro, Yuya; Miyazaki, Tohru; Homma, Misaki; Mori, Kouji; Iwai, Kenichi; Hara, Hideto; Skene, Robert; Hoffman, Isaac; Ohashi, Akihiro; Yoshida, Sei; Ishikawa, Tomoyasu; Cho, Nobuo

2017-04-01

Cell division cycle 7 (Cdc7) is a serine/threonine kinase that plays important roles in the regulation of DNA replication process. A genetic study indicates that Cdc7 inhibition can induce selective tumor-cell death in a p53-dependent manner, suggesting that Cdc7 is an attractive target for the treatment of cancers. In order to identify a new class of potent Cdc7 inhibitors, we generated a putative pharmacophore model based on in silico docking analysis of a known inhibitor with Cdc7 homology model. The pharmacophore model provided a minimum structural motif of Cdc7 inhibitor, by which preliminary medicinal chemistry efforts identified a dihydrothieno[3,2-d]-pyrimidin-4(1H)-one scaffold having a heteroaromatic hinge-binding moiety. The structure-activity relationship (SAR) studies resulted in the discovery of new, potent, and selective Cdc7 inhibitors 14a, c, e. Furthermore, the high selectivity of 14c, e for Cdc7 over Rho-associated protein kinase 1 (ROCK1) is discussed by utilizing a docking study with Cdc7 and ROCK2 crystal structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

Dgachi, Youssef; Bautista-Aguilera, Oscar M; Benchekroun, Mohamed; Martin, Hélène; Bonet, Alexandre; Knez, Damijan; Godyń, Justyna; Malawska, Barbara; Gobec, Stanislav; Chioua, Mourad; Janockova, Jana; Soukup, Ondrej; Chabchoub, Fakher; Marco-Contelles, José; Ismaili, Lhassane

2016-05-14

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

Direct reductive amination of aldehyde bisulfite adducts induced by 2-picoline borane: application to the synthesis of a DPP-IV inhibitor.

PubMed

Faul, Margaret; Larsen, Rob; Levinson, Adam; Tedrow, Jason; Vounatsos, Filisaty

2013-02-15

Aldehyde-bisulfite adducts dervied from unstable parent aldehydes were reductively alkylated in a direct fashion with a variety of amines. This approach features the use of 2-picoline borane as the reducing agent and a protic solvent for the reaction media and has been successfully applied to the synthesis of a DPP-IV inhibitor and a variety of other amines.

Novel diamide-based inhibitors of IMPDH.

PubMed

Gu, Henry H; Iwanowicz, Edwin J; Guo, Junqing; Watterson, Scott H; Shen, Zhongqi; Pitts, William J; Dhar, T G Murali; Fleener, Catherine A; Rouleau, Katherine; Sherbina, N Z; Witmer, Mark; Tredup, Jeffrey; Hollenbaugh, Diane

2002-05-06

A series of novel amide-based small molecule inhibitors of inosine monophosphate dehydrogenase is described. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are presented.

Treatment with protein synthesis inhibitors improves outcomes from secondary bacterial pneumonia following influenza

PubMed Central

Karlström, Åsa; Boyd, Kelli L.; English, B. Keith; McCullers, Jonathan A.

2008-01-01

Pneumonia as a secondary infection after influenza is a major cause of excess morbidity and mortality despite the availability and use of antibiotics active against Streptococcus pneumoniae. We hypothesized that use of a bacteriostatic protein synthesis inhibitor would improve outcomes by reducing the inflammatory response. BALB/c mice infected with influenza virus and super-infected with Streptococcus pneumoniae were treated with either the cell wall active antibiotic ampicillin or protein synthesis inhibitors clindamycin or azithromycin. Ampicillin therapy performed significantly worse (56% survival) in the model compared to clindamycin therapy either alone (82%) or in combination with ampicillin (80%) and to azithromycin (92%). Improved survival appeared to be mediated by decreased inflammation manifested as lower levels of inflammatory cells and pro-inflammatory cytokines in the lungs, and less severe histopathology. These data suggest that beta-lactam therapy may not be optimal as first line treatment of community acquired pneumonia when it follows influenza. PMID:19113989

Synthesis and evaluation of novel triazoles and mannich bases functionalized 1,4-dihydropyridine as angiotensin converting enzyme (ACE) inhibitors.

PubMed

Kumbhare, Ravindra M; Kosurkar, Umesh B; Bagul, Pankaj K; Kanwal, Abhinav; Appalanaidu, K; Dadmal, Tulshiram L; Banerjee, Sanjay Kumar

2014-11-01

A series of novel diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate embedded triazole and mannich bases were synthesized, and evaluated for their angiotensin converting enzyme (ACE) inhibitory activity. Screening of above synthesized compounds for ACE inhibition showed that triazoles functionalized compounds have better ACE inhibitory activity compared to that of mannich bases analogues. Among all triazoles we found 6 h, 6 i and 6 j to have good ACE inhibition activity with IC50 values 0.713 μM, 0.409 μM and 0.653 μM, respectively. Among mannich bases series compounds, only 7c resulted as most active ACE inhibitor with IC50 value of 0.928 μM. Copyright © 2014. Published by Elsevier Ltd.

Nonprenylated Xanthones from Gentiana lutea, Frasera caroliniensis, and Centaurium erythraea as Novel Inhibitors of Vascular Smooth Muscle Cell Proliferation.

PubMed

Waltenberger, Birgit; Liu, Rongxia; Atanasov, Atanas G; Schwaiger, Stefan; Heiss, Elke H; Dirsch, Verena M; Stuppner, Hermann

2015-11-13

Aberrant proliferation of vascular smooth muscle cells (VSMC) plays a major role in restenosis, the pathological renarrowing of the blood vessel lumen after surgical treatment of stenosis. Since available anti-proliferative pharmaceuticals produce unfavorable side effects, there is high demand for the identification of novel VSMC proliferation inhibitors. A natural product screening approach using a resazurin conversion assay enabled the identification of gentisin (1) from Gentiana lutea as a novel inhibitor of VSMC proliferation with an IC50 value of 7.84 µM. Aiming to identify further anti-proliferative compounds, 13 additional nonprenylated xanthones, isolated from different plant species, were also tested. While some compounds showed no or moderate activity at 30 µM, 1-hydroxy-2,3,4,5-tetramethoxyxanthone (4), swerchirin (6), and methylswertianin (7) showed IC50 values between 10.2 and 12.5 µM. The anti-proliferative effect of 1, 4, 6, and 7 was confirmed by the quantification of DNA synthesis (BrdU incorporation) in VSMC. Cell death quantification (determined by LDH release in the culture medium) revealed that the compounds are not cytotoxic in the investigated concentration range. In conclusion, nonprenylated xanthones are identified as novel, non-toxic VSMC proliferation inhibitors, which might contribute to the development of new therapeutic applications to combat restenosis.

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

PubMed

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

2017-12-14

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

Synthesis of ST7612AA1, a Novel Oral HDAC Inhibitor, via Radical 
Thioacetic Acid Addition.

PubMed

Battistuzzi, Gianfranco; Giannini, Giuseppe

2016-12-01

In the expanding field of anticancer drugs, HDAC inhibitors are playing an increasingly important role. To date, four/five HDAC inhibitors have been approved by FDA. All these compounds fit the widely accepted HDAC inhibitors pharmacophore model characterized by a cap group, a linker chain and a zinc binding group (ZBG), able to bind the Zn 2+ ion in a pocket of the HDAC active site. Romidepsin, a natural compound, is the only thiol derivative. We have selected a new class of synthetic HDAC inhibitors, the thio-ω(lactam-carboxamide) derivatives, with ST7612AA1 as drug candidate, pan-inhibitor active in the range of single- to two-digit nanomolar concentrations. Preliminary results of a synthetic optimization attempt towards a fast scale-up process are here proposed. In the four steps of synthesis, from unsaturated amino acid intermediate to the final product, we explored different synthetic conditions in order to have a transferable process for a scale-up synthetic laboratory. In the first step, isobutyl chloroformate was used and, after a simple work up with 1M HCl, 2 (96% yield) was obtained as a white solid, which was used directly in the next step. For thioacetic acid addition to the double bond of intermediate 2 , two different routes were possible, with addition reaction in the first (D') or last step (D). Reactions of 2 to give 5 or of 4 to give ST7612AA1 were both performed in dioxane. Reactions were fast and did not need the usually advised radical quenching with cyclohexene. The corresponding products were obtained in good yields (step D', 89%; step D, 81%) after a flash chromatography. , a thiol derivative prodrug of ST7464AA1 , is the first of a new generation of HDAC inhibitors, very potent, orally administered, and well tolerated. Here, we have identified a synthetic route, competitive, versatile and easily transferable to industrial processes.

ROLE OF NEUROTRANSMITTERS AND PROTEIN SYNTHESIS IN SHORT- AND LONG-TERM MEMORY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, E.L.; Rosenzweig, M.R.; Flood, J.F.

1978-10-01

Anisomycin is an effective inhibitor of cerebral protein synthesis in mice and is also an effective amnestic agent for both passive and active behavioral tasks. From use of anisomycin in combination with a variety of stimulant and depressant drugs, we conclude that the level of arousal following acquisition plays an important role in determining the duration and the rate of the biosynthetic phase of memory formation. While we have interpreted the experiments with anisomycin as evidence for an essential role of protein in memory storage, others have suggested that side effects of inhibitors of protein synthesis on catecholamine metabolism aremore » the main cause of amnesia. Several experiments were therefore done to compare the effects of anisemycin and catecholamine inhibitors on memory. We conclude that anisomycin's principal amnestic mechanism does not involve inhibition of the catecholamine system. The results strengthen our conclusion that protein synthesis is an essential component for longterm memory trace formation. Also, it is suggested that proteins synthesized in the neuronal cell body are used, in conjunction with other molecules, to produce permanent and semi-permanent anatomical changes.« less

Comparison of specificity of inhibition of polyamine synthesis in bovine lymphocytes by ethylglyoxal bis(guanylhydrazone) and methylglyoxal bis(guanylhydrazone).

PubMed

Igarashi, K; Porter, C W; Morris, D R

1984-11-01

Ethylglyoxal bis(guanylhydrazone) (EGBG) was compared as an inhibitor of polyamine biosynthesis with methylglyoxal bis(guanylhydrazone) (MGBG) in bovine small lymphocytes stimulated by concanavalin A. EGBG brought about a decrease in spermidine and spermine levels equal to that found with MGBG, but at a 5-fold lower intracellular drug concentration. Despite identical polyamine levels, the degree of inhibition of DNA and protein synthesis by EGBG was smaller than that observed with MGBG, in either the presence or absence of the ornithine decarboxylase inhibitor, alpha-difluoromethylornithine. It was found that in vitro protein synthesis and in vivo mitochondrial function were inhibited by concentrations of MGBG necessary to inhibit polyamine synthesis in cells (1 to 3 mM), but not by efficacious levels of EGBG (0.2 to 0.6 mM). These results suggest that EGBG is more suitable as a specific inhibitor of polyamine biosynthesis and that use of this drug, rather than MGBG, in combination with alpha-difluoromethylornithine may be useful for studying the physiological functions of polyamines in animal cells.

High fat-diet and saturated fatty acid palmitate inhibits IGF-1 function in chondrocytes.

PubMed

Nazli, S A; Loeser, R F; Chubinskaya, S; Willey, J S; Yammani, R R

2017-09-01

Insulin-like growth factor-1 (IGF-1) promotes matrix synthesis and cell survival in cartilage. Chondrocytes from aged and osteoarthritic cartilage have a reduced response to IGF-1. The purpose of this study was to determine the effect of free fatty acids (FFA) present in a high-fat diet on IGF-1 function in cartilage and the role of endoplasmic reticulum (ER) stress. C57BL/6 male mice were maintained on either a high-fat (60% kcal from fat) or a low-fat (10% kcal from fat) diet for 4 months. Mice were then sacrificed; femoral head cartilage caps were collected and treated with IGF-1 to measure proteoglycan (PG) synthesis. Cultured human chondrocytes were treated with 500 μM FFA palmitate or oleate, followed by stimulation with (100 ng/ml) IGF-1 overnight to measure CHOP (a protein marker for ER stress) and PG synthesis. Human chondrocytes were pre-treated with palmitate or 1 mM 4-phenyl butyric acid (PBA) or 1 μM C-Jun N terminal Kinase (JNK) inhibitor, and IGF-1 function (PG synthesis and signaling) was measured. Cartilage explants from mice on the high fat-diet showed reduced IGF-1 mediated PG synthesis compared to a low-fat group. Treatment of human chondrocytes with palmitate induced expression of CHOP, activated JNK and inhibited IGF-1 function. PBA, a small molecule chemical chaperone that alleviates ER stress rescued IGF-1 function and a JNK inhibitor rescued IGF-1 signaling. Palmitate-induced ER stress inhibited IGF-1 function in chondrocytes/cartilage via activating the mitogen-activated protein (MAP) kinase JNK. This is the first study to demonstrate that ER stress is metabolic factor that regulates IGF-1 function in chondrocytes. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Selected phytotoxins and organic extracts from endophytic fungus Edenia gomezpompae as light reaction of photosynthesis inhibitors.

PubMed

Macías-Rubalcava, Martha Lydia; Ruiz-Velasco Sobrino, María Emma; Meléndez-González, Claudio; King-Díaz, Beatriz; Lotina-Hennsen, Blas

2014-09-05

In a search for natural herbicides, we investigated the action mechanism of the naphthoquinone spiroketals, isolated from the endophytic fungus Edenia gomezpompae: preussomerins EG1 (1) and EG4 (2), and palmarumycins CP17 (3), and CP2 (4) on the photosynthesis light reactions. The naphthoquinone spiroketals 1-4 inhibited the ATP synthesis in freshly lysed spinach thylakoids from water to MV, and they also inhibited the non-cyclic electron transport in the basal, phosphorylating and uncoupled conditions from water to MV. Therefore, they act as Hill reaction inhibitors. The results suggested that naphthoquinone spiroketals 1-4 have two interactions and inhibition site on the PSII electron transport chain. The first one involves the water splitting enzyme inhibition; and, the second on the acceptor site of PSII in a similar way that herbicide Diuron, studied by polaroghaphy and corroborated by fluorescence of the chlorophyll a of PSII. The culture medium and mycelium organic extracts from four morphological variants of E. gomezpompae were phytotoxic, and the culture medium extracts were more potent than mycelium extracts. They also act as Hill reaction inhibitors. Copyright © 2014 Elsevier B.V. All rights reserved.

Peripheral Injection of SB203580 Inhibits the Inflammatory-Dependent Synthesis of Proinflammatory Cytokines in the Hypothalamus

PubMed Central

Herman, Andrzej P.; Krawczyńska, Agata; Antushevich, Hanna

2014-01-01

The study was designed to determine the effects of peripheral injection of SB203580 on the synthesis of interleukin- (IL-) 1β, IL-6, and tumor necrosis factor (TNF) α in the hypothalamus of ewes during prolonged inflammation. Inflammation was induced by the administration of lipopolysaccharide (LPS) (400 ng/kg) over 7 days. SB203580 is a selective ATP-competitive inhibitor of the p38 mitogen-activated protein kinase (MAPK), which is involved in the regulation of proinflammatory cytokines IL-1β, IL-6 and TNFα synthesis. Intravenous injection of SB203580 successfully inhibited (P < 0.01) synthesis of IL-1β and reduced (P < 0.01) the production of IL-6 in the hypothalamus. The p38 MAPK inhibitor decreased (P < 0.01) gene expression of TNFα but its effect was not observed at the level of TNFα protein synthesis. SB203580 also reduced (P < 0.01) LPS-stimulated IL-1 receptor type 1 gene expression. The conclusion that inhibition of p38 MAPK blocks LPS-induced proinflammatory cytokine synthesis seems to initiate new perspectives in the treatment of chronic inflammatory diseases also within the central nervous system. However, potential proinflammatory effects of SB203580 treatment suggest that all therapies using p38 MAPK inhibitors should be introduced very carefully with analysis of all expected and unexpected consequences of treatment. PMID:24995301

Activity-dependent rapid local RhoA synthesis is required for hippocampal synaptic plasticity.

PubMed

Briz, Victor; Zhu, Guoqi; Wang, Yubin; Liu, Yan; Avetisyan, Mariam; Bi, Xiaoning; Baudry, Michel

2015-02-04

Dendritic protein synthesis and actin cytoskeleton reorganization are important events required for the consolidation of hippocampal LTP and memory. However, the temporal and spatial relationships between these two processes remain unclear. Here, we report that treatment of adult rat hippocampal slices with BDNF or with tetraethylammonium (TEA), which induces a chemical form of LTP, produces a rapid and transient increase in RhoA protein levels. Changes in RhoA were restricted to dendritic spines of CA3 and CA1 and require de novo protein synthesis regulated by mammalian target of rapamycin (mTOR). BDNF-mediated stimulation of RhoA activity, cofilin phosphorylation, and actin polymerization were completely suppressed by protein synthesis inhibitors. Furthermore, intrahippocampal injections of RhoA antisense oligodeoxynucleotides inhibited theta burst stimulation (TBS)-induced RhoA upregulation in dendritic spines and prevented LTP consolidation. Addition of calpain inhibitors after BDNF or TEA treatment maintained RhoA levels elevated and prolonged the effects of BDNF and TEA on actin polymerization. Finally, the use of isoform-selective calpain inhibitors revealed that calpain-2 was involved in RhoA synthesis, whereas calpain-1 mediated RhoA degradation. Overall, this mechanism provides a novel link between dendritic protein synthesis and reorganization of the actin cytoskeleton in hippocampal dendritic spines during LTP consolidation. Copyright © 2015 the authors 0270-6474/15/352269-14$15.00/0.

THE ACTION OF α-AMANITIN ON RNA SYNTHESIS IN CHINESE HAMSTER OVARY CELLS

PubMed Central

Kedinger, Claude; Simard, Rene

1974-01-01

α-Amanitin acts in vitro as a selective inhibitor of the nucleoplasmic form B RNA polymerases. Treatment of Chinese hamster ovary (CHO) cells with this drug leads principally to a severe fragmentation of the nucleoli. While the ultrastructural lesions induced by α-amanitin in CHO cells and in rat or mouse liver are quite similar, the results diverge concerning the effect on RNA synthesis. It has been shown that in rat or mouse liver α-amanitin blocks both extranucleolar and nucleolar RNA synthesis. Our autoradiographic and biochemical evidence indicates that in CHO cells high molecular weight extranucleolar RNA synthesis (HnRNA) is blocked by the α-amanitin treatment, whereas nucleolar RNA (preribosomal RNA) synthesis remains unaffected even several hours after the inhibition of extranucleolar RNA synthesis. Furthermore, the processing of this RNA as well as its transport to the cytoplasm seem only slightly affected by the treatment. Finally, under these conditions, the synthesis of the low molecular RNA species (4–5S) still occurs, though less actively. The results are interpreted as evidence for a selective impairment of HnRNA synthesis by α-amanitin in CHO cells. PMID:4474178

Inhibition of chitin biosynthesis in cultured imaginal discs: Effects of alpha-amanitin, actinomycin-D, cycloheximide, and puromycin.

PubMed

Oberlander, Herbert; Ferkovich, Stephen; Leach, Eddie; Van Essen, Frank

1980-02-01

Wing imaginal discs isolated from last instar larvae of the Indian meal moth,Plodia interpunctella, produced chitin when incubated in vitro with ≧2×10 -7 M 20-hydroxyecdysone. Chitin biosynthesis was initiated 8 h after the conclusion of a 24-h treatment with hormone. Simulataneous incubation of wing discs with 20-hydroxyecdysone and either inhibitors of RNA synthesis (alpha-amanitin, actinomycin-D) or inhibitors of protein systhesis (cycloheximide, puromycin) prevented chitin biosynthesis. We conclude from our results that RNA and protein synthesis must continue undiminished during the hormone-contact period, and that synthesis of protein, but not of new RNA is required during the posthormone culture period. Our findings are consistent with the hypothesis that ecdysteroids stimulate insect metamorphosis by promoting the synthesis of new RNA and protein during a hormone-dependent phase followed by hormone-independent protein synthesis.

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

PubMed

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

2017-02-01

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

Cytological characteristics and classification of spindle inhibitors according to their effects on segmentation mitoses.

PubMed

Sentein, P; Ates, Y

1978-01-01

The effects of spindle inhibitors and of protein synthesis inhibitors on segmentation mitoses allow us to classify them into six groups : 1. Colchicine type : destruction of the whole achromatic apparatus and centrospheres without storing of dense bodies; 2. Quinoline type : same effect on the achromatic apparatus, but blocked centrospheres with accumulation of dense bodies; 3. Chloralhydrate type : Incomplete destruction of achromatic apparatus, spindle residue which maintains the chromosomes in a star shape, inactive centrospheres sequestered by the reticulum, but without accumulation of dense bodies; 4. Phenylurethane type : Incomplete and reversible action, which leads to easy production of pluripolar mitoses; 5. Carboxylic acid type : dissociation of the spindle, sometimes with blocking of the centrosphere, together with profound chromosome changes without primitive breaks; the intensity and quality of their action is related to the number of carbon atoms in the acid considered; 6. Protein synthesis inhibitor type : (cycloheximide, pederin) characterized by a stop of the nuclear cycle at telo-prophase when the action is sufficient, chromosome abnormalities, sometimes, reduced to strings of beads, and freeing of asters; at weaker concentrations mitosis is possible, but the congression of chromosomes at the equator is abnormal because of functional disturbance of the kinetochores. The nature and grading of these effects, their association (or non - association) to chromosome damage, the soundness of the spindle when only the chromosomes are affected (nitrogen mustard) make this one of the tests which gives the most specific data about the action of antimitotic substances.

Comparing myotoxic effects of squalene synthase inhibitor, T-91485, and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in human myocytes.

PubMed

Nishimoto, Tomoyuki; Tozawa, Ryuichi; Amano, Yuichiro; Wada, Takeo; Imura, Yoshimi; Sugiyama, Yasuo

2003-12-01

TAK-475 is a squalene synthase inhibitor, rapidly metabolized to T-91485 in vivo. We investigated the myotoxicities of T-91485 and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in a human rhabdomyosarcoma cell line, RD, and in human skeletal myocytes. In differentiated RD cells, T-91485, atorvastatin (ATV) and simvastatin acid (SIM) inhibited cholesterol biosynthesis, with IC(50) values of 36, 2.8 and 3.8 nM, respectively. ATV and SIM decreased the intracellular ATP content, with IC(25) values (concentrations giving a 25% decrease in intracellular ATP content) of 0.61 and 0.44 microM, respectively. Although T-91485 potently inhibited cholesterol synthesis in RD cells, the IC(25) value exceeded 100 microM. In human skeletal myocytes, T-91485, ATV and SIM concentration-dependently inhibited cholesterol biosynthesis, with IC(50) values of 45, 8.6 and 8.4 nM, respectively. ATV and SIM decreased intracellular ATP content, with IC(25) values of 2.1 and 0.72 microM, respectively. Although T-91485 potently inhibited cholesterol synthesis, the IC(25) value exceeded 100 microM. Myotoxicity induced by ATV was prevented by mevalonate or geranylgeranyl-PP, but not by squalene in skeletal cells. Furthermore, T-91485 attenuated the myotoxicity of ATV. These findings suggest that TAK-475 and T-91485 may not only be far from myotoxic, they may also decrease statin-induced myotoxicity in lipid-lowering therapy.

Comparative toxicity of 20 herbicides to 5 periphytic algae and the relationship with mode of action.

PubMed

Nagai, Takashi; Taya, Kiyoshi; Yoda, Ikuko

2016-02-01

The authors used 5 species of periphytic algae to conduct toxicity assays of 20 herbicides. The 5 tested species represent riverine primary producers most likely to be affected by herbicides. A fluorescence microplate toxicity assay was used as an efficient and economical high-throughput assay. Toxicity characteristics were analyzed, focusing on their relationship to herbicide mode of action. The relative differences between 50% and 10% effect concentrations depended on herbicide mode of action, rather than tested species. Moreover, a clear relationship between sensitive species and herbicide mode of action was also observed. Green alga was most sensitive to herbicides of 2 mode of action groups: inhibitors of protoporphyrinogen oxidase and very long-chain fatty acid synthesis. Diatoms were most sensitive to herbicides of 1 mode of action group: 4-hydroxyphenyl-pyruvate-dioxygenase inhibitors. Cyanobacterium was most sensitive to herbicides of 1 mode of action group: inhibitors of acetolactate synthase. The species sensitivity distribution based on obtained data was also analyzed. The slopes of the species sensitivity distribution significantly differed among modes of action, suggesting that difference in species sensitivity is specific to the mode of action. In particular, differences in species sensitivity were markedly large for inhibitors of acetolactate synthase, protoporphyrinogen oxidase, and very long-chain fatty acid synthesis. The results clearly showed that a single algal species cannot represent the sensitivity of an algal assemblage. Therefore, multispecies algal toxicity data are essential for substances with specific modes of action. © 2015 SETAC.

Cross Talk between Nucleotide Synthesis Pathways with Cellular Immunity in Constraining Hepatitis E Virus Replication

PubMed Central

Wang, Yijin; Wang, Wenshi; Xu, Lei; Zhou, Xinying; Shokrollahi, Ehsan; Felczak, Krzysztof; van der Laan, Luc J. W.; Pankiewicz, Krzysztof W.; Sprengers, Dave; Raat, Nicolaas J. H.; Metselaar, Herold J.; Peppelenbosch, Maikel P.

2016-01-01

Viruses are solely dependent on host cells to propagate; therefore, understanding virus-host interaction is important for antiviral drug development. Since de novo nucleotide biosynthesis is essentially required for both host cell metabolism and viral replication, specific catalytic enzymes of these pathways have been explored as potential antiviral targets. In this study, we investigated the role of different enzymatic cascades of nucleotide biosynthesis in hepatitis E virus (HEV) replication. By profiling various pharmacological inhibitors of nucleotide biosynthesis, we found that targeting the early steps of the purine biosynthesis pathway led to the enhancement of HEV replication, whereas targeting the later step resulted in potent antiviral activity via the depletion of purine nucleotide. Furthermore, the inhibition of the pyrimidine pathway resulted in potent anti-HEV activity. Interestingly, all of these inhibitors with anti-HEV activity concurrently triggered the induction of antiviral interferon-stimulated genes (ISGs). Although ISGs are commonly induced by interferons via the JAK-STAT pathway, their induction by nucleotide synthesis inhibitors is completely independent of this classical mechanism. In conclusion, this study revealed an unconventional novel mechanism of cross talk between nucleotide biosynthesis pathways and cellular antiviral immunity in constraining HEV infection. Targeting particular enzymes in nucleotide biosynthesis represents a viable option for antiviral drug development against HEV. HEV is the most common cause of acute viral hepatitis worldwide and is also associated with chronic hepatitis, especially in immunocompromised patients. Although often an acute and self-limiting infection in the general population, HEV can cause severe morbidity and mortality in certain patients, a problem compounded by the lack of FDA-approved anti-HEV medication available. In this study, we have investigated the role of the nucleotide synthesis pathway in HEV infection and its potential for antiviral drug development. We show that targeting the later but not the early steps of the purine synthesis pathway exerts strong anti-HEV activity. In particular, IMP dehydrogenase (IMPDH) is the most important anti-HEV target of this cascade. Importantly, the clinically used IMPDH inhibitors, including mycophenolic acid and ribavirin, have potent anti-HEV activity. Furthermore, targeting the pyrimidine synthesis pathway also exerts potent antiviral activity against HEV. Interestingly, antiviral effects of nucleotide synthesis pathway inhibitors appear to depend on the medication-induced transcription of antiviral interferon-stimulated genes. Thus, this study reveals an unconventional novel mechanism as to how nucleotide synthesis pathway inhibitors can counteract HEV replication. PMID:26926637

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

ERIC Educational Resources Information Center

Touaibia, Mohamed; Guay, Michel

2011-01-01

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

Effects of proteasome inhibitors MG132, ZL3VS and AdaAhx3L3VS on protein metabolism in septic rats

PubMed Central

Kadlčíková, Jana; Holeček, Milan; Šafránek, Roman; Tilšer, Ivan; Kessler, Benedikt M

2004-01-01

Proteasome inhibitors are novel therapeutic agents for the treatment of cancer and other severe disorders. One of the possible side effects is influencing the metabolism of proteins. The aim of our study was to evaluate the influence of three proteasome inhibitors MG132, ZL3VS and AdaAhx3L3VS on protein metabolism and leucine oxidation in incubated skeletal muscle of control and septic rats. Total proteolysis was determined according to the rates of tyrosine release into the medium during incubation. The rates of protein synthesis and leucine oxidation were measured in a medium containing L-[1-14C]leucine. Protein synthesis was determined as the amount of L-[1-14C]leucine incorporated into proteins, and leucine oxidation was evaluated according to the release of 14CO2 during incubation. Sepsis was induced in rats by means of caecal ligation and puncture. MG132 reduced proteolysis by more than 50% and protein synthesis by 10–20% in the muscles of healthy rats. In septic rats, proteasome inhibitors, except ZL3VS, decreased proteolysis in both soleus and extensor digitorum longus (EDL) muscles, although none of the inhibitors had any effect on protein synthesis. Leucine oxidation was increased by AdaAhx3L3VS in the septic EDL muscle and decreased by MG132 in intact EDL muscle. We conclude that MG132 and AdaAhx3L3VS reversed protein catabolism in septic rat muscles. PMID:15566433

Antimicrobial Treatment for Systemic Anthrax: Analysis of Cases from 1945–2014 Identified through Systematic Literature Review

PubMed Central

Pillai, Satish K.; Huang, Eileen; Guarnizo, Julie; Hoyle, Jamechia; Katharios-Lanwermeyer, Stefan; Turski, Theresa; Bower, William; Hendricks, Katherine; Meaney-Delman, Dana

2015-01-01

Background Systemic anthrax is associated with high mortality. Current national guidelines, developed for the individualized treatment of systemic anthrax, outline the use of combination intravenous antimicrobials for a minimum of two weeks; bactericidal and protein synthesis inhibitor antimicrobials for all cases of systemic anthrax; and at least 3 antimicrobials with good blood-brain barrier penetration for anthrax meningitis. However, in an anthrax mass casualty incident, large numbers of anthrax cases may create challenges in meeting antimicrobial needs. Methods To further inform our understanding of the role of antimicrobials in treating systemic anthrax, a systematic review of the English language literature was conducted to identify cases of systemic anthrax treated with antimicrobials for which a clinical outcome was recorded. Results A total of 149 cases of systemic anthrax were identified (cutaneous [n=59], gastrointestinal [n=28], inhalation [n=26], primary anthrax meningitis [n=19], multiple routes [n=9], and injection [n=8]). Among the identified 59 cases of cutaneous anthrax, 33 were complicated by meningitis (76% mortality), while 26 simply had evidence of the systemic inflammatory response syndrome (4% mortality); 21 of 26 (81%) of this latter group received monotherapy. Subsequent analysis regarding combination antimicrobial therapy was restricted to the remaining 123 cases of more severe anthrax (overall 67% mortality). Recipients of combination bactericidal and protein synthesis inhibitor therapy had a 45% survival versus 28% in the absence of combination therapy (p = 0.07). For meningitis cases (n=77), survival was greater for those receiving a total of ≥3 antimicrobials over the course of treatment (3 of 4; 75%), compared to receipt of 1 or 2 antimicrobials (12 of 73; 16%) (p = 0.02). Median parenteral antimicrobial duration was 14 days. Conclusion Combination bactericidal and protein synthesis inhibitor therapy may be appropriate in severe anthrax disease, particularly anthrax meningitis, in a mass casualty incident. PMID:26623698

Glutamate release from activated microglia requires the oxidative burst and lipid peroxidation.

PubMed

Barger, Steven W; Goodwin, Mary E; Porter, Mandy M; Beggs, Marjorie L

2007-06-01

When activated by proinflammatory stimuli, microglia release substantial levels of glutamate, and mounting evidence suggests this contributes to neuronal damage during neuroinflammation. Prior studies indicated a role for the Xc exchange system, an amino acid transporter that antiports glutamate for cystine. Because cystine is used for synthesis of glutathione (GSH) synthesis, we hypothesized that glutamate release is an indirect consequence of GSH depletion by the respiratory burst, which produces superoxide from NADPH oxidase. Microglial glutamate release triggered by lipopolysaccharide was blocked by diphenylene iodonium chloride and apocynin, inhibitors of NADPH oxidase. This glutamate release was also blocked by vitamin E and elicited by lipid peroxidation products 4-hydroxynonenal and acrolein, suggesting that lipid peroxidation makes crucial demands on GSH. Although NADPH oxidase inhibitors also suppressed nitrite accumulation, vitamin E did not; moreover, glutamate release was largely unaffected by nitric oxide donors, inhibitors of nitric oxide synthase, or changes in gene expression. These findings indicate that a considerable degree of the neurodegenerative consequences of neuroinflammation may result from conversion of oxidative stress to excitotoxic stress. This phenomenon entails a biochemical chain of events initiated by a programmed oxidative stress and resultant mass-action amino acid transport. Indeed, some of the neuroprotective effects of antioxidants may be due to interference with these events rather than direct protection against neuronal oxidation.

Synthesis and Biological Assessment of Racemic Benzochromenopyrimidinimines as Antioxidant, Cholinesterase, and Aβ1-42 Aggregation Inhibitors for Alzheimer's Disease Therapy.

PubMed

Dgachi, Youssef; Ismaili, Lhassane; Knez, Damijan; Benchekroun, Mohamed; Martin, Hélène; Szałaj, Natalia; Wehle, Sarah; Bautista-Aguilera, Oscar M; Luzet, Vincent; Bonnet, Alexandre; Malawska, Barbara; Gobec, Stanislav; Chioua, Mourad; Decker, Michael; Chabchoub, Fakher; Marco-Contelles, José

2016-06-20

Given the complex nature of Alzheimer's disease (AD), compounds that are able to simultaneously address two or more AD-associated targets show greater promise for development into drugs for AD therapy. Herein we report an efficient two-step synthesis and biological evaluation of new racemic benzochromene derivatives as antioxidants, inhibitors of cholinesterase and β-amyloid (Aβ1-42 ) aggregation. Based on the results of the primary screening, we identified 15-(3-methoxyphenyl)-9,11,12,15-tetrahydro-10H,14H-benzo[5,6]chromeno[2,3-d]pyrido[1,2-a]pyrimidin-14-imine (3 e) and 16-(3-methoxyphenyl)-9,10,11,12,13,16-hexahydro-15H-benzo[5',6']chromeno[2',3':4,5]pyrimido[1,2-a]azepin-15-imine (3 f) as new potential multitarget-directed ligands for AD therapy. Further in-depth biological analysis showed that compound 3 f is a good human acetylcholinesterase inhibitor [IC50 =(0.36±0.02) μm], has strong antioxidant activity (3.61 μmol Trolox equivalents), and moderate Aβ1-42 antiaggregating power (40.3 %). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and Biological Evaluation of 3-Benzylidene-4-chromanone Derivatives as Free Radical Scavengers and α-Glucosidase Inhibitors.

PubMed

Takao, Koichi; Yamashita, Marimo; Yashiro, Aruki; Sugita, Yoshiaki

2016-01-01

A series of 3-benzylidene-4-chromanone derivatives (3-20) were synthesized and the structure-activity relationships for antioxidant and α-glucosidase inhibitory activities were evaluated. Among synthesized compounds, compounds 5, 13, 18, which contain catechol moiety, showed the potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity (5: EC50 13 µM; 13: EC50 14 µM; 18: EC50 13 µM). The compounds 12, 14, 18 showed higher α-glucosidase inhibitory activity (12: IC50 15 µM; 14: IC50 25 µM; 18: IC50 28 µM). The compound 18 showed both of potent DPPH radical scavenging and α-glucosidase inhibitory activities. These data suggest that 3-benzylidene-4-chromanone derivatives, such as compound 18, may serve as the lead compound for the development of novel α-glucosidase inhibitors with antioxidant activity.

Synthesis and biological evaluation of novel alkyl diamine linked bivalent β-carbolines as angiogenesis inhibitors.

PubMed

Chen, Wei; Zhang, Guoxian; Guo, Liang; Fan, Wenxi; Ma, Qin; Zhang, Xiaodong; Du, Runlei; Cao, Rihui

2016-11-29

We have synthesized and evaluated a series of novel alkyl diamine linked bivalent β-carbolines as potent angiogenesis inhibitors. The results demonstrated that most bivalent β-carbolines exhibited significant antiproliferative effects against human umbilical vein cell lines EA.HY926. Compound 4m was found to be the most potent antiproliferative agent with IC 50 value of 2.16 μM against EA.HY926 cell lines. Mechanism investigations revealed that compound 4m could significantly inhibit EA.HY926 cells migration and tube formation in a dose-dependent manner. Moreover, compound 4m also showed obvious angiogenesis inhibitory effects in CAM assay, and the antiangiogenetic potency was more potent than the reference drug Endostar. The bivalent β-carbolines might be served as candidates for the development of vascular targeting antitumor drugs. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Hippuristanol - A potent steroid inhibitor of eukaryotic initiation factor 4A

PubMed Central

Cencic, Regina; Pelletier, Jerry

2016-01-01

ABSTRACT Protein synthesis and its regulatory signaling pathways play essential roles in the initiation and maintenance of the cancer phenotype. Insight obtained over the last 3 decades on the mechanisms regulating translation in normal and transformed cells have revealed that perturbed control in cancer cells may offer an Achilles' heel for the development of novel anti-neoplastic agents. Several small molecule inhibitors have been identified and characterized that target translation initiation – more specifically, the rate-limiting step where ribosomes are recruited to mRNA templates. Among these, hippuristanol, a polyhydroxysteroid from the gorgonian Isis hippuris has been found to inhibit translation initiation by blocking the activity of eukaryotic initiation factor (eIF) 4A, an essential RNA helicase involved in this process. Herein, we highlight the biological properties of this compound, its potential development as an anti-cancer agent, and its use to validate eIF4A as an anti-neoplastic target. PMID:27335721

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

PubMed

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

2016-10-01

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

Inhibition of putrescine synthesis blocks development of the polychete Ophryotrocha labronica at gastrulation.

PubMed Central

Emanuelsson, H; Heby, O

1978-01-01

Development eggs of the polychete Ophryotrocha labronica were analyzed for polyamines during the first 6 days after fertilization. The spermine content dominated initially, but gradually decreased. It was surpassed by putrescine, which rapidly increased to a maximum on the 3rd day, i.e., at the inception of grastrulation. The spermidine content was low during the entire period. Treatment of eggs with the putrescine synthesis inhibitor alpha-methylornithine from the onset of development led to developmental arrest at gastrulation and to an abnormally low content of putrescine in the treated embryos. Methylglyoxal bis(guanylhydrazone), an inhibitor of spermine and spermidine synthesis, had no visible effect of development. Our observations strongly suggest that putrescine synthesis is indispensable in early embryonic development of Ophryotrocha. Images PMID:273215

Design and synthesis of novel 2-(indol-5-yl)thiazole derivatives as xanthine oxidase inhibitors.

PubMed

Song, Jeong Uk; Choi, Sung Pil; Kim, Tae Hun; Jung, Cheol-Kyu; Lee, Joo-Youn; Jung, Sang-Hun; Kim, Geun Tae

2015-03-15

Xanthine oxidase (XO) inhibitors have been widely used for the treatment of gout. Indole rings are frequently used as active scaffold in designing inhibitors for enzymes. Herein, we describe the structure-activity relationship for novel xanthine oxidase inhibitors based on indole scaffold. A series of novel tri-substituted 2-(indol-5-yl)thiazole derivatives were synthesized, and their in vitro inhibitory activities against xanthine oxidase and in vivo efficacy lowering uric acid level in blood were measured. Among them, 2-(3-cyano-2-isopropylindol-5-yl)-4-methylthiazole-5-carboxylic acid exhibits the most potent XO inhibitory activity (IC50 value: 3.5nM) and the excellent plasma uric acid lowering activity. Study of structure activity relationship indicated that hydrophobic moiety (e.g., isopropyl) at 1-position and electron withdrawing group (e.g., CN) at 3-position of indole ring and small hydrophobic group (CH3) at 4-position of the thiazole ring enhanced the XO inhibitory activity. Hydrophobic substitution such as isopropyl at 1-position of the indole moiety without any substitution at 2-position has an essential role for enhancing bioavailability and therefore for high in vivo efficacy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and biological evaluation of novel aromatic and heterocyclic bis-sulfonamide Schiff bases as carbonic anhydrase I, II, VII and IX inhibitors.

PubMed

Akocak, Suleyman; Lolak, Nabih; Nocentini, Alessio; Karakoc, Gulcin; Tufan, Anzel; Supuran, Claudiu T

2017-06-15

A series of sixteen novel aromatic and heterocyclic bis-sulfonamide Schiff bases were prepared by conjugation of well known aromatic and heterocyclic aminosulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor pharmacophores with aromatic and heterocyclic bis-aldehydes. The obtained bis-sulfonamide Schiff bases were investigated as inhibitors of four selected human (h) CA isoforms, hCA I, hCA II, hCA VII and hCA IX. Most of the newly synthesized compounds showed a good inhibitory profile against isoforms hCA II and hCA IX, also showing moderate selectivity against hCA I and VII. Several efficient lead compounds were identified among this bis-sulfonamide Schiff bases with low nanomolar to sub-nanomolar activity against hCA II (K i s ranging between 0.4 and 861.1nM) and IX (K i s between 0.5 and 933.6nM). Since hCA II and hCA IX are important drug targets (antiglaucoma and anti-tumor agents), these isoform-selective inhibitors may be considered of interest for various biomedical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

8-hydroxyquinoline inhibition of DNA synthesis and intragenic recombination during yeast meiosis.

PubMed

Mills, D

1978-06-14

Complete inhibition of sporulation was observed in two strains of Saccharomyces cerevisiae to which 8-hydroxyquinoline was added at a final concentration of 5 microgram/ml during the initial 4 to 6 h of sporulation. The cells were most sensitive to the inhibitor during 4 to 6 interval beginning at approximately 2 h (T2). Its addition during that interval resulted in 70 to 80% lethality in strain 4579 and about 40% in API at T24. When present from T0 onward, 5 microgram/ml of 8-hydroxyquinoline severely inhibited premeiotic DNA replication and reduced the frequency of intragenic recombination at the ade 2 and leu 2 loci by 70 and 100%, respectively, relative to control cultures which did not have the inhibitor present. During the period when the cells were most sensitive, the incorporation of 14C-leucine into protein and 14C-adenine into RNA was not inhibited nor was the polysome content affected. At 150 microgram/ml of inhibitor, incorporation of labeled precursors into RNA and protein were inhibited and the percentage of active ribosomes was reduced by 35% within 45 min, but neither transcription or translation appeared to be completely inhibited at this concentration of the inhibitor.

Design, synthesis, and antihypertensive activity of curcumin-inspired compounds via ACE inhibition and vasodilation, along with a bioavailability study for possible benefit in cardiovascular diseases.

PubMed

Zhuang, Xiao-Dong; Liao, Li-Zhen; Dong, Xiao-Bian; Hu, Xun; Guo, Yue; Du, Zhi-Min; Liao, Xin-Xue; Wang, Li-Chun

2016-01-01

This study describes the synthesis of a novel series of curcumin-inspired compounds via a facile synthetic route. The structures of these derivatives were ascertained using various spectroscopic and analytic techniques. The pharmacological effects of the target analogs were assessed by assaying their inhibition of angiotensin-converting enzyme (ACE). All of the synthesized derivatives exhibited considerable inhibition of ACE, with half-maximal inhibitory concentrations ranging from 1.23 to 120.32 μM. In a docking analysis with testicular ACE (tACE), the most promising inhibitor (4j) was efficiently accommodated in the deep cleft of the protein cavity, making close interatomic contacts with Glu162, His353, and Ala356, comparable with lisinopril. Compounds 4i, 4j, 4k, and 4l were further selected for determination of their vasodilator activity (cardiac output and stroke volume) on isolated rat hearts using the Langendorff technique. The bioavailability of compound 4j was determined in experimental mice.

Stereoselective construction of the 5-hydroxy diazabicyclo[4.3.1]decane-2-one scaffold, a privileged motif for FK506-binding proteins.

PubMed

Bischoff, Matthias; Sippel, Claudia; Bracher, Andreas; Hausch, Felix

2014-10-17

A stereoselective synthesis of a derivatized bicyclic [4.3.1]decane scaffold based on an acyclic precursor is described. The key steps involve a Pd-catalyzed sp(3)-sp(2) Negishi-coupling, an asymmetric Shi epoxidation, and an intramolecular epoxide opening. Representative derivatives of this novel scaffold were synthesized and found to be potent inhibitors of the psychiatric risk factor FKBP51, which bound to FKBP51 with the intended molecular binding mode.

Ectodomain shedding of TNF receptor 1 induced by protein synthesis inhibitors regulates TNF-{alpha}-mediated activation of NF-{kappa}B and caspase-8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogura, Hirotsugu; Tsukumo, Yoshinori; Department of Bioengineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501

2008-04-01

The transcription factor nuclear factor {kappa}B (NF-{kappa}B) plays a major role in the inducible resistance to death receptor-mediated apoptosis. It has been established that the protein synthesis inhibitor cycloheximide (CHX) sensitizes many types of cells to tumor necrosis factor (TNF)-{alpha}-induced apoptosis, mainly due to its ability to block de novo synthesis of cellular FLICE-inhibitory protein (c-FLIP). Nevertheless, we have surprisingly found that CHX, as well as its structural analogue acetoxycycloheximide (Ac-CHX), prevents TNF-{alpha}-mediated activation of NF-{kappa}B and caspase-8 in human lung carcinoma A549 cells. Both CHX and Ac-CHX reduced the expression of cell surface TNF receptor 1 (TNF-R1) in amore » dose-dependent manner, while Ac-CHX was approximately 100-fold more effective than CHX. Consistent with this observation, Ac-CHX induced the proteolytic cleavage of TNF-R1 and its release into the culture medium. CHX and Ac-CHX profoundly decreased constitutive and inducible expression of c-FLIP, whereas these compounds potentiated TNF-{alpha}-induced caspase-8 activation only when metalloprotease inhibitors were present. Thus, our results indicate that ectodomain shedding of TNF-R1 induced by protein synthesis inhibitors regulates TNF-{alpha}-mediated activation of NF-{kappa}B and caspase-8.« less

Synthesis of Benzo[a]carbazoles and an Indolo[2,3-a]carbazole from 3-Aryltetramic Acids.

PubMed

Truax, Nathanyal J; Banales Mejia, Fernando; Kwansare, Deborah O; Lafferty, Megan M; Kean, Maeve H; Pelkey, Erin T

2016-08-05

A simple and flexible approach to 3-pyrrolin-2-one fused carbazoles is disclosed. The key step involves the BF3-mediated electrophilic substitution of indoles with N-alkyl-substituted 3-aryltetramic acids, which provides access to indole-substituted 3-pyrrolin-2-ones. Scholl-type oxidative cyclizations of these materials led to the formation of the corresponding 3-pyrrolin-2-one-fused benzo[a]carbazoles and indolo[2,3-a]carbazoles. This work represents the first synthesis of the benzo[a]pyrrolo[3,4-c]carbazol-3(8H)-one ring system, while the indolo[2,3-a]pyrrolo[3,4-c]carbazol-5-one ring system is found in a number of biologically active compounds including the protein kinase C (PKC) inhibitor, staurosporine.

Targeting FASN in Breast Cancer and the Discovery of Promising Inhibitors from Natural Products Derived from Traditional Chinese Medicine

PubMed Central

Cheng, Chien-shan; Wang, Zhiyu; Chen, Jianping

2014-01-01

Molecular targeted therapy has been developed for cancer chemoprevention and treatment. Cancer cells process a fundamental change in its bioenergetic metabolism from normal cells on an altered lipid metabolism, also known as the de novo fatty acid synthesis, for sustaining their high proliferation rates. Fatty acid synthesis is now associated with clinically aggressive tumor behavior and tumor cell growth and has become a novel target pathway for chemotherapy development. Although the underlying mechanisms of the altered de novo fatty acid synthesis still remains unclear, recent progress has shown that by targeting Fatty acid synthase (FASN), a key enzyme that catalyzes the synthesis of endogenous long chain fatty acid could be a critical target for drug discovery. However, relatively few FASN inhibitors have been discovered. With the long history of clinical practices and numerous histological case study reports, traditional Chinese medicine enjoys an important role in seeking bioactive anticancer natural compounds. Herein, we will give an overall picture of the current progress of molecular targeted therapy in cancer fatty acid synthesis, describe the advances in the research on natural products-derived FASN inhibitors and their potential for enhancing our understanding of fatty acids in tumor biology, and may provide new therapeutic moieties for breast cancer patient care. PMID:24778702

PROTEIN PROFILING OF XENOPUS LAEVIS BRAIN CELLS FOLLOWING EXPOSURE TO T4-SYNTHESIS INHIBITORS: POTENTIAL APPLICATION TO THE ASSESSMENT/DIAGNOSIS OF XENOBIOTICS THAT PERTURB THE THYROID PATHWAY

EPA Science Inventory

To address USEPA's need for a cost effective, non-mammalian screening assay for thyroid axis disrupting chemicals, a multi-endpoint strategy combining molecular and in vivo protocols in an amphibian model is being applied at MED-Duluth. To support the molecular phase goals of thi...

Neo-synthesis of estrogenic or androgenic neurosteroids determine whether long-term potentiation or depression is induced in hippocampus of male rat

PubMed Central

Di Mauro, Michela; Tozzi, Alessandro; Calabresi, Paolo; Pettorossi, Vito Enrico; Grassi, Silvarosa

2015-01-01

Estrogenic and androgenic steroids synthesized in the brain may rapidly modulate synaptic plasticity interacting with specific membrane receptors. We explored by electrophysiological recordings in hippocampal slices of male rat the influence of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) neo-synthesis on the synaptic changes induced in the CA1 region. Induction of long-term depression (LTD) and depotentiation (DP) by low frequency stimulation (LFS, 15 min-1 Hz) and of long-term potentiation (LTP) by high frequency stimulation (HFS, 1 s-100 Hz), medium (MFS, 1 s-50 Hz), or weak (WFS, 1 s-25 Hz) frequency stimulation was assayed under inhibitors of enzymes converting testosterone (T) into DHT (5α-reductase) and T into E2 (P450-aromatase). We found that LFS-LTD depends on DHT synthesis, since it was fully prevented under finasteride, an inhibitor of DHT synthesis, and rescued by exogenous DHT, while the E2 synthesis was not involved. Conversely, the full development of HFS-LTP requires the synthesis of E2, as demonstrated by the LTP reduction observed under letrozole, an inhibitor of E2 synthesis, and its full rescue by exogenous E2. For intermediate stimulation protocols DHT, but not E2 synthesis, was involved in the production of a small LTP induced by WFS, while the E2 synthesis was required for the MFS-dependent LTP. Under the combined block of DHT and E2 synthesis all stimulation frequencies induced partial LTP. Overall, these results indicate that DHT is required for converting the partial LTP into LTD whereas E2 is needed for the full expression of LTP, evidencing a key role of the neo-synthesis of sex neurosteroids in determining the direction of synaptic long-term effects. PMID:26483631

Potent and selective inhibitors of 11β-hydroxysteroid dehydrogenase type 1 labeled with carbon-13 and carbon-14.

PubMed

Latli, Bachir; Hrapchak, Matt; Savoie, Jolaine; Zhan, Yongda; Busacca, Carl A; Senanayake, Chris H

2017-07-01

(S)-6-(2-Hydroxy-2-methylpropyl)-3-((S)-1-(4-(1-methyl-2-oxo-1,2-dihydropyridin-4-yl)phenyl)ethyl)-6-phenyl-1,3-oxazinan-2-one (1) and (4aR,9aS)-1-(1H-benzo[d]midazole-5-carbonyl)-2,3,4,4a,9,9a-hexahydro-1-H-indeno[2,1-b]pyridine-6-carbonitrile hydrochloride (2) are potent and selective inhibitor of 11β-hydroxysteroid dehydrogenase type 1 enzyme. These 2 drug candidates developed for the treatment of type-2 diabetes were prepared labeled with carbon-13 and carbon-14 to enable drug metabolism, pharmacokinetics, bioanalytical, and other studies. In the carbon-13 synthesis, benzoic- 13 C 6 acid was converted in 7 steps and in 16% overall yield to [ 13 C 6 ]-(1). Aniline- 13 C 6 was converted in 7 steps to 1H-benzimidazole-1-2,3,4,5,6- 13 C 6 -5-carboxylic acid and then coupled to a tricyclic chiral indenopiperidine to afford [ 13 C 6 ]-(2) in 19% overall yield. The carbon-14 labeled (1) was prepared efficiently in 2 radioactive steps in 41% overall yield from an advanced intermediate using carbon-14 labeled methyl magnesium iodide and Suzuki-Miyaura cross coupling via in situ boronate formation. As for the synthesis of [ 14 C]-(2), 1H-benzimidazole-5-carboxylic- 14 C acid was first prepared in 4 steps using potassium cyanide- 14 C, then coupled to the chiral indenopiperidine using amide bond formation conditions in 26% overall yield. Copyright © 2017 John Wiley & Sons, Ltd.

Inhibition of the synthesis of polyamines and DNA in activated lymphocytes by a combination of alpha-methylornithine and methylglyoxal bis(guanylhydrazone).

PubMed

Morris, D R; Jorstad, C M; Seyfried, C E

1977-09-01

The cancer chemotherapeutic drug, methylglyoxal bis(guanylhydrazone), inhibits the synthesis of spermidine and spermine, but allows continued putrescine production in small lymphocytes stimulated by concanavalin A. DNA replication in these cells is inhibited 50% while the synthesis of protein and RNA continues normally. When excess putrescine accumulation in the presence of methylglyoxal bis(guanylhydrazone) was inhibited with alpha-methylornithine, a competitive inhibitor of ornithine decarboxylase, the inhibition of DNA replication was accentuated, with still no effect on protein or RNA synthesis. No inhibition of DNA synthesis by the combination of alpha-methylornithine and methylglyoxal bis(guanylhydrazone) was observed when the inhibitors were added after accumulation of cellular polyamines. In addition, inhibition was reversed by exogenous putrescine, spermidine, or spermine. We conclude that putrescine can fulfill in part the role normally played by spermidine and spermine in DNA replication, and that blocking putrescine synthesis in the presence of methylglyoxal bis(guanylhydrazone) amplifies the polyamine requirement. The implications of this with regard to polyamine synthesis as a site of chemotherapy are discussed.

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

PubMed

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

1996-06-01

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

One-pot microwave assisted synthesis under green chemistry conditions, antioxidant screening, and cytotoxicity assessments of benzimidazole Schiff bases and pyrimido[1,2-a]benzimidazol-3(4H)-ones.

PubMed

Neochoritis, Constantinos G; Zarganes-Tzitzikas, Tryfon; Tsoleridis, Constantinos A; Stephanidou-Stephanatou, Julia; Kontogiorgis, Christos A; Hadjipavlou-Litina, Dimitra J; Choli-Papadopoulou, Theodora

2011-01-01

The synthesis of a number of benzimidazole Schiff bases 3 and 3-oxo-pyrimido[1,2-a]benzimidazoles 4 in excellent yields by a one-step sequence from the reaction of 2-aminobenzimidazole under green chemistry conditions is described. Structural assignments of the new compounds as well as complete assignment of (1)H and (13)C NMR signals have been unambiguously achieved based on the analysis of their (1)H and (13)C NMR (1D and 2D), IR, MS and elemental analysis data. To the synthesized Schiff bases the E-configuration was assigned on the basis of comparison of experimental and calculated (DFT) (13)C NMR chemical shifts. Compounds 3 and 4 were evaluated as inhibitors of lipoxygenase (LOX) and of lipid peroxidation (LPO). All the tested derivatives showed inhibition of lipid peroxidation, whereas most of them were found to have higher activation than the reference compound trolox; The Schiff bases 3e, 3h, and 3i, and the pyrimidobenzimidazoles 4a, 4e and 4f were found to be the most potent. The most potent LOX inhibitor within the subset of Schiff bases was found compound 3i, followed by 3f, whereas compounds 4a and 4g were found the most potent of the 3-oxo-pyrimido[1,2-a]benzimidazole group. Moreover, some cytotoxicity assessments were undertaken, whereupon it was found that Schiff base 3i and pyrimidobenzimidazoles 4e and 4f did not exhibit cytotoxicity at similar concentrations resembling thus the inhibitory activity of lipid peroxidation. The most cytotoxic Schiff base and pyrimidobenzimidazole were found to be 3d and 4c, respectively. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Identification of fused 16β,17β-oxazinone-estradiol derivatives as a new family of non-estrogenic 17β-hydroxysteroid dehydrogenase type 1 inhibitors.

PubMed

Maltais, René; Trottier, Alexandre; Delhomme, Audrey; Barbeau, Xavier; Lagüe, Patrick; Poirier, Donald

2015-03-26

A new family of cyclic carbamate-estradiol derivatives has been designed to remove the intrinsic estrogenic activity of a parent acyclic compound reported as a potent inhibitor of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1). The synthesis of two series of fused 16β,17β-oxazinone-estradiol derivatives, saturated compounds 7a-d and unsaturated compounds 10a-d, led to the identification of 10b, a 17β-HSD1 inhibitor (IC50 = 1.4 μM) without estrogenic activity in estrogen-sensitive T-47D cells. Interestingly, this compound was found selective over 17β-HSD2 and 17β-HSD12. A computational analysis of inhibitors into 17β-HSD1 by molecular docking also revealed interesting structure-activity relationships that could be helpful in the design of new generation of 16β,17β-oxazinone-estradiol analogs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Structure-based design, synthesis and biological evaluation of β-glucuronidase inhibitors

NASA Astrophysics Data System (ADS)

Khan, Khalid M.; Ambreen, Nida; Taha, Muhammad; Halim, Sobia A.; Zaheer-ul-Haq; Naureen, Shagufta; Rasheed, Saima; Perveen, Shahnaz; Ali, Sajjad; Choudhary, Mohammad Iqbal

2014-05-01

Using structure-based virtual screening approach, a coumarin derivative ( 1) was identified as β-glucuronidase inhibitor. A focused library of coumarin derivatives was synthesized by eco-benign version of chemical reaction, and all synthetic compounds were characterized by using spectroscopy. These compounds were found to be inhibitor of β-glucuronidase with IC50 values in a micromolar range. All synthetic compounds exhibited interesting inhibitory activity against β-glucuronidase, however, their potency varied substantially from IC50 = 9.9-352.6 µM. Of twenty-one compounds, four exhibited a better inhibitory profile than the initial hit 1. Interestingly, compounds 1e, 1k, 1n and 1p exhibited more potency than the standard inhibitor with IC50 values 34.2, 21.4, 11.7, and 9.9 µM, respectively. We further studied their dose responses and also checked our results by using detergent Triton ×-100. We found that our results are true and not affected by detergent.

Structure-based design, synthesis and biological evaluation of β-glucuronidase inhibitors.

PubMed

Khan, Khalid M; Ambreen, Nida; Taha, Muhammad; Halim, Sobia A; Zaheer-ul-Haq; Naureen, Shagufta; Rasheed, Saima; Perveen, Shahnaz; Ali, Sajjad; Choudhary, Mohammad Iqbal

2014-05-01

Using structure-based virtual screening approach, a coumarin derivative (1) was identified as β-glucuronidase inhibitor. A focused library of coumarin derivatives was synthesized by eco-benign version of chemical reaction, and all synthetic compounds were characterized by using spectroscopy. These compounds were found to be inhibitor of β-glucuronidase with IC50 values in a micromolar range. All synthetic compounds exhibited interesting inhibitory activity against β-glucuronidase, however, their potency varied substantially from IC50 = 9.9-352.6 µM. Of twenty-one compounds, four exhibited a better inhibitory profile than the initial hit 1. Interestingly, compounds 1e, 1k, 1n and 1p exhibited more potency than the standard inhibitor with IC50 values 34.2, 21.4, 11.7, and 9.9 µM, respectively. We further studied their dose responses and also checked our results by using detergent Triton ×-100. We found that our results are true and not affected by detergent.

Synthesis and evaluation of novel amide amino-β-lactam derivatives as cholesterol absorption inhibitors.

PubMed

Dražić, Tonko; Sachdev, Vinay; Leopold, Christina; Patankar, Jay V; Malnar, Martina; Hećimović, Silva; Levak-Frank, Sanja; Habuš, Ivan; Kratky, Dagmar

2015-05-15

The β-lactam cholesterol absorption inhibitor ezetimibe is so far the only representative of this class of compounds on the market today. The goal of this work was to synthesize new amide ezetimibe analogs from trans-3-amino-(3R,4R)-β-lactam and to test their cytotoxicity and activity as cholesterol absorption inhibitors. We synthesized six new amide ezetimibe analogs. All new compounds exhibited low toxicity in MDCKIIwt, hNPC1L1/MDCKII and HepG2 cell lines and showed significant inhibition of cholesterol uptake in hNPC1L1/MDCKII cells. In addition, we determined the activity of the three compounds to inhibit cholesterol absorption in vivo. Our results demonstrate that these compounds considerably reduce cholesterol concentrations in liver and small intestine of mice. Thus, our newly synthesized amide ezetimibe analogs are cholesterol absorption inhibitors in vitro and in vivo. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

PubMed

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

2015-08-01

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

Design, synthesis and docking studies of novel dipeptidyl boronic acid proteasome inhibitors constructed from αα- and αβ-amino acids.

PubMed

Shi, Jingmiao; Lei, Meng; Wu, Wenkui; Feng, Huayun; Wang, Jia; Chen, Shanshan; Zhu, Yongqiang; Hu, Shihe; Liu, Zhaogang; Jiang, Cheng

2016-04-15

A series of novel dipeptidyl boronic acid proteasome inhibitors constructed from αα- and αβ-amino acids were designed and synthesized. Their structures were elucidated by (1)H NMR, (13)C NMR, LC-MS and HRMS. These compounds were evaluated for their β5 subunit inhibitory activities of human proteasome. The results showed that dipeptidyl boronic acid inhibitors composed of αα-amino acids were as active as bortezomib. Interestingly, the activities of those derived from αβ-amino acids lost completely. Of all the inhibitors, compound 22 (IC50=4.82 nM) was the most potent for the inhibition of proteasome activity. Compound 22 was also the most active against three MM cell lines with IC50 values less than 5 nM in inhibiting cell growth assays. Molecular docking studies displayed that 22 fitted very well in the β5 subunit active pocket of proteasome. Copyright © 2016. Published by Elsevier Ltd.

Discovery and development of pyrazole-scaffold Hsp90 inhibitors.

PubMed

McDonald, Edward; Jones, Keith; Brough, Paul A; Drysdale, Martin J; Workman, Paul

2006-01-01

This review explains why the chaperone Hsp90 is an exciting protein target for the discovery of new drugs to treat cancer in the clinic, and summarises the properties of natural product derived inhibitors before relating the discovery and current state of development of synthetic pyrazole compounds. Blockade of Hsp90 results in reduced cellular levels of several proteins implicated in cancer including CDK4, ERBB2 and C-RAF, and causes simultaneous inhibition of cancer cell proliferation in culture and of tumor xenograft growth in vivo. Hsp90 has an ATPase domain that is necessary for its Hsp chaperone function, and X-ray crystallography has shown that natural product inhibitors (geldanamycin, radicicol) of Hsp90 function bind to this domain. High throughput assays focusing on the ATPase activity of Hsp90 were developed and used to discover novel chemical starting points for cancer drug discovery. The discovery, synthesis and SAR of 3,4-diaryl pyrazoles is described. X-Ray crystallography of protein-inhibitor complexes revealed important interactions involving the resorcinol substituent at C-3, and these X-ray structures strongly influenced subsequent medicinal chemistry research that has resulted in highly potent inhibitors with sub-micromolar activity in cells. SAR and X-ray data are summarised for analogues in which the 4-phenyl substituent is replaced by amides or piperazine derivatives. Prospects for the pyrazoles as they progress towards clinical development are discussed in relation to current Phase I trials with derivatives of geldanamycin.

Synthesis and Biological Evaluation of 4-Sulfamoylphenyl/Sulfocoumarin Carboxamides as Selective Inhibitors of Carbonic Anhydrase Isoforms hCA II, IX, and XII.

PubMed

Angapelly, Srinivas; Angeli, Andrea; Khan, Arbaj Jabbar; Sri Ramya, P V; Supuran, Claudiu T; Arifuddin, Mohammed

2018-04-19

With the aim to develop potent and selective human carbonic anhydrase inhibitors (hCAIs), we synthesized 4-sulfamoylphenyl/sulfocoumarin benzamides (series 5 a-r and series 7 a-q) and evaluated their inhibition profiles against five isoforms of the zinc-containing human carbonic anhydrase (hCA, EC 4.2.1.1): cytosolic hCA I and II, and the transmembrane isozymes hCA IV, IX, and XII. Compounds 5 a-r were found to selectively inhibit hCA II in the nanomolar range, while being less effective against the other hCA isoforms. As noted from the literature, sulfocoumarin (1,2-benzoxathiine 2,2-dioxide) acts as a "prodrug" inhibitor and is hydrolyzed by the esterase activity of hCA to form 2-hydroxyphenylvinylsulfonic acid, which thereafter binds to the enzyme in a manner similar to that of coumarins and sulfoxocoumarins. All these sulfocoumarins (compounds 7 a-q) were found to be very weak or ineffective as inhibitors of the housekeeping off-target hCA isoforms I and II, and effectively inhibited the transmembrane tumor-associated isoforms IX and XII in the high nanomolar to micromolar ranges. Further structural modifications of these molecules could be useful for the development of effective hCA inhibitors used for the treatment of glaucoma, epilepsy, and cancer. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of a Novel Dithiocarbamate Glutathione Reductase Inhibitor and Its Use as a Tool to Modulate Intracellular Glutathione*

PubMed Central

Seefeldt, Teresa; Zhao, Yong; Chen, Wei; Raza, Ashraf S.; Carlson, Laura; Herman, Jocqueline; Stoebner, Adam; Hanson, Sarah; Foll, Ryan; Guan, Xiangming

2009-01-01

Thiol redox state (TRS) is an important parameter to reflect intracellular oxidative stress and is associated with various normal and abnormal biochemical processes. Agents that can be used to increase intracellular TRS will be valuable tools in TRS-related research. Glutathione reductase (GR) is a critical enzyme in the homeostasis of TRS. The enzyme catalyzes the reduction of GSSG to GSH to maintain a high GSH:GSSG ratio. Inhibition of the enzyme can be used to increase TRS. Despite the reports of various GR inhibitors, N,N-bis(2-chloroethyl)-N-nitrosourea, an anticancer drug with IC50 = 647 μm against yeast GR, remains the most commonly used GR inhibitor in the literature. However, the toxicity caused by nonspecific interactions, as well as inhibition of DNA synthesis, complicates the use of N,N-bis(2-chloroethyl)-N-nitrosourea as a GR inhibitor. We report 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanylthiocarbonylamino)phenylthiocarbamoylsulfanyl]propionic acid (2-AAPA) as a novel irreversible GR inhibitor. 2-AAPA was prepared by one-step synthesis from commercially available reagents. The Ki and kinact of 2-AAPA against yeast GR were determined to be 56 μm and 0.1 min–1, respectively. At the concentration that produced >80% yeast GR inhibition, 2-AAPA showed no inhibition against glutamylcysteine synthetase, glutathione synthetase, catalase, and superoxide dismutase, but minimal inhibition against glutathione S-transferase and glutathione peroxidase. In CV-1 cells, 2-AAPA (0.1 mm) produced 97% GR inhibition, 25% GSH reduction, and a 5-fold increase in GSSG in 20 min. The compound can be a useful tool in TRS-related research. PMID:19049979

Novel amide-based inhibitors of inosine 5'-monophosphate dehydrogenase.

PubMed

Watterson, Scott H; Liu, Chunjian; Dhar, T G Murali; Gu, Henry H; Pitts, William J; Barrish, Joel C; Fleener, Catherine A; Rouleau, Katherine; Sherbina, N Z; Hollenbaugh, Diane L; Iwanowicz, Edwin J

2002-10-21

A series of novel amide-based small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH) was explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are described.

Highly Potent HIV-1 Protease Inhibitors with Novel Tricyclic P2-ligands: Design, Synthesis, and Protein-ligand X-Ray Studies

PubMed Central

Ghosh, Arun K.; Parham, Garth L.; Martyr, Cuthbert D.; Nyalapatla, Prasanth R.; Osswald, Heather L.; Agniswamy, Johnson; Wang, Yuan-Fang; Amano, Masayuki; Weber, Irene T.; Mitsuya, Hiroaki

2013-01-01

The design, synthesis, and biological evaluation of a series of HIV-1 protease inhibitors incorporating stereochemically defined fused tricyclic P2-ligands are described. Various substituent effects were investigated in order to maximize the ligand-binding site interactions in the protease active site. Inhibitors 16a and 16f showed excellent enzyme inhibitory and antiviral activity while incorporation of sulfone functionality resulted in a decrease in potency. Both inhibitors 16a and 16f have maintained activity against a panel of multidrug resistant HIV-1 variants. A high-resolution X-ray crystal structure of 16a-bound HIV-1 protease revealed important molecular insights into the ligand-binding site interactions which may account for the inhibitor’s potent antiviral activity and excellent resistance profiles. PMID:23947685

Novel Pieces for the Emerging Picture of Sulfoximines in Drug Discovery: Synthesis and Evaluation of Sulfoximine Analogues of Marketed Drugs and Advanced Clinical Candidates.

PubMed

Sirvent, Juan Alberto; Lücking, Ulrich

2017-04-06

Sulfoximines have gained considerable recognition as an important structural motif in drug discovery of late. In particular, the clinical kinase inhibitors for the treatment of cancer, roniciclib (pan-CDK inhibitor), BAY 1143572 (P-TEFb inhibitor), and AZD 6738 (ATR inhibitor), have recently drawn considerable attention. Whilst the interest in this underrepresented functional group in drug discovery is clearly on the rise, there remains an incomplete understanding of the medicinal-chemistry-relevant properties of sulfoximines. Herein we report the synthesis and in vitro characterization of a variety of sulfoximine analogues of marketed drugs and advanced clinical candidates to gain a better understanding of this neglected functional group and its potential in drug discovery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regulation of Hemoglobin β-Chain Synthesis in Bone Marrow Erythroid Cells by α Chains

PubMed Central

Wolf, Jeffrey L.; Mason, R. George; Honig, George R.

1973-01-01

Synthesis of α and β chains of hemoglobin was studied in vitro in intact reticulocytes and bone marrow cells. The cells were from rabbits having a variant form of hemoglobin in which L-isoleucine is in the α but not in the β chains. This characteristic permitted a selective inhibition of α-chain synthesis to be produced by addition to the incubation medium of L-O-methylthreonine, an inhibitor of protein synthesis that is a specific antagonist of L-isoleucine. In studies with reticulocytes, 25 mM L-O-methylthreonine produced a 60-70% inhibition of α-chain synthesis, but β-chain synthesis was unaffected even after incubation times for 4 hr. Because reticulocytes contain a pool of uncombined α chains which might have obscured the demonstration of an α chain-dependent mechanism for β-chain synthesis, subsequent studies were done with bone marrow cells. The latter had little or no detectable α-chain pool. A substantial inhibition of α-chain synthesis by the bone marrow cells was produced by the isoleucine antagonist but was also accompanied by a significantly decreased rate of β-chain synthesis. These findings suggest that the coordinated synthesis of the complementary α- and β-globin chains of hemoglobin may reflect in part a modifying effect of α-chain synthesis on the synthesis of β chains. PMID:4519634

Inhibition of endothelial cell expression of plasminogen activator inhibitor type-1 by gemfibrozil.

PubMed

Fujii, S; Sawa, H; Sobel, B E

1993-10-18

Increased concentrations of plasminogen activator inhibitor type-1 (PAI-1) in plasma are associated with impaired fibrinolysis and venous and arterial thrombo-embolic disease. In pilot studies designed to identify pharmacologic approaches capable of diminishing such increases, we found that gemfibrozil attenuated the stimulation of synthesis of PAI-1 in a human, immortal, hepatoma cell line (Hep G2) induced by platelets. The present study was performed to determine whether it exerts analogous effects in non-immortal endothelial cells and whether it may therefore facilitate fibrinolysis locally in vivo. Human umbilical vein endothelial cells were incubated with pharmacologic concentrations of gemfibrozil. Gemfibrozil, 100 microM, suppressed basal PAI-1 production by 15% and attenuated the augmentation of synthesis of PAI-1 induced by lysates from platelets (4 x 10(7)/ml) by 36% over 24 h without inhibiting overall protein synthesis. In addition, the increases in PAI-1 mRNA otherwise induced by platelet lysates over 6 h were suppressed by 49% (Northern blots) without any demonstrable change in the intracellular half-life of PAI-1 mRNA. Pulse-chase experiments demonstrated diminution of PAI-1 protein synthesis in parallel with the changes observed in PAI-1 mRNA. To determine whether these effects of gemfibrozil on endothelial cells in vitro were paralleled by consistent changes in the concentrations of PAI-1 in plasma in vivo, we studied rabbits with induced carotid artery thrombosis and thrombolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary screen for potential sheep scab control agents.

PubMed

Dunn, J A; Prickett, J C; Collins, D A; Weaver, R J

2016-07-15

The efficacy of potential acaricidal agents were assessed against the sheep scab mite Psoroptes ovis using a series of in vitro assays in modified test arenas designed initially to maintain P. ovis off-host. The mortality effects of 45 control agents, including essential oils, detergents, desiccants, growth regulators, lipid synthesis inhibitors, nerve action/energy metabolism disruptors and ecdysteroids were assessed against adults and nymphs. The most effective candidates were the desiccants (diatomaceous earth, nanoclay and sorex), the growth regulators (buprofezin, hexythiazox and teflubenzuron), the lipid synthesis inhibitors (spirodiclofen, spirotetramat and spiromesifen) and the nerve action and energy metabolism inhibitors (fenpyroximate, spinosad, tolfenpyrad, and chlorantraniliprole). Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Investigational therapies for the treatment of atherosclerosis.

PubMed

Tomkin, Gerald H; Owens, Daphne

2014-10-01

There is great need for new drugs to reduce cholesterol in those patients who have not achieved target levels on statins as well as those who are statin intolerant. In this review, the authors discuss the new antisense oligotide inhibitor of apo B synthesis, mipomersen; pro-protein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and cholesterol ester transport protein (CETP) inhibitors. Furthermore, the authors discuss cholesterol absorption and chylomicron synthesis with an emphasis on microsomal triglyceride transfer protein (MTP) inhibitors, which inhibit very-low-density lipoprotein production in the liver and chylomicron inhibition in the intestine. Finally, the authors also discuss Apo A1- and adenosine triphosphate-binding cassette transporter A1 (ABCA1)-promoting drugs. A literature review was performed through PubMed using the terms atherosclerosis, hypercholesterolemia, Apo B inhibition, PSCK9, CETP inhibitors, MTP inhibitors, apo A1 mimetics and ABCA1. So far, research suggests that PCSK9 inhibitors will be successful with mipomersen being used for those patients who do not respond well or who are still not at target. However, it is difficult to see where CETP inhibitors will fit in except with patients who have very low high-density lipoprotein. The MTP inhibitor lomitapide is currently only licensed for familial homozygous hypercholesterolemia but the intestinal inhibitors may have a future, particularly in familial combined hyperlipidemia. The future will be most exciting.

Novel aldehyde and thiosemicarbazone derivatives: Synthesis, spectroscopic characterization, structural studies and molecular docking studies

NASA Astrophysics Data System (ADS)

Karakurt, Tuncay; Tahtaci, Hakan; Subasi, Nuriye Tuna; Er, Mustafa; Ağar, Erbil

2016-12-01

In this study our purpose is that, synthesis and characterization of compounds containing the aldehyde and thiosemicarbazone groups and comparison of the theoretical results with the experimental results. The structures of all synthesized compounds were elucidated by IR, 1H NMR, 13C NMR, elemental analyses techniques. The structure of compound (4) (C9H8N4O2S) was also elucidated by X-ray diffraction analysis. In addition, the theoretical IR spectrum, 1H NMR and 13C NMR chemical shift values, frontier molecular orbital values (FMO) of these molecules were analyzed by using Becke-3- Lee-Yang-Parr (B3LYP) method with LanL2DZ basis set. Finally, molecular docking studies were performed on synthesized compounds using the 4DKI beta-lactam protein structure to determine the potential binding mode of inhibitors.

A survey of cyclic replacements for the central diamide moiety of inhibitors of inosine monophosphate dehydrogenase.

PubMed

Dhar, T G Murali; Liu, Chunjian; Pitts, William J; Guo, Junquing; Watterson, Scott H; Gu, Henry; Fleener, Catherine A; Rouleau, Katherine; Sherbina, N Z; Barrish, Joel C; Hollenbaugh, Diane; Iwanowicz, Edwin J

2002-11-04

A series of heterocyclic replacements for the central diamide moiety of 1, a potent small molecule inhibitor of inosine monophosphate dehydrogenase (IMPDH) were explored The synthesis and the structure-activity relationships (SARs), derived from in vitro studies, for these new series of inhibitors is given.

Heterogeneous effects of tissue inhibitors of matrix metalloproteinases on cardiac fibroblasts.

PubMed

Lovelock, Joshua D; Baker, Andrew H; Gao, Feng; Dong, Jing-Fei; Bergeron, Angela L; McPheat, Willie; Sivasubramanian, Natarajan; Mann, Douglas L

2005-02-01

The balance between matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), plays a critical role in cardiac remodeling. Although a number of studies have characterized the pathophysiological role of MMPs in the heart, very little is known with respect to the role of TIMPs in the heart. To delineate the role of TIMPs in the heart we examined the effects of adenovirus-mediated overexpression of TIMP-1, -2, -3, and -4 in cardiac fibroblasts. Infection of cardiac fibroblasts with adenoviral constructs containing human recombinant TIMP (AdTIMP-1, -2, -3, and -4) provoked a significant (P < 0.0001) 1.3-fold in increase in bromodeoxyuridine (BrdU) incorporation. Similarly, treatment of cardiac fibroblasts with AdTIMP-1-, -2-, -3-, and -4-conditioned medium led to a 1.2-fold increase in BrdU incorporation (P < 0.0001) that was abolished by pretreatment with anti-TIMP-1, -2, -3, and -4 antibodies. The effects of TIMPs were not mimicked by treating the cells with RS-130830, a broad-based MMP inhibitor, suggesting that the effects of TIMPs were independent of their ability to inhibit MMPs. Infection with AdTIMP-1, -2, -3, and -4 led to a significant increase in alpha-smooth muscle actin staining, consistent with TIMP-induced phenotypic differentiation into myofibroblasts. Finally, infection with AdTIMP-2 resulted in a significant increase in collagen synthesis, whereas infection with AdTIMP-3 resulted in a significant increase in fibroblast apoptosis. TIMPs exert overlapping as well as diverse effects on isolated cardiac fibroblasts. The observation that TIMPs stimulate fibroblast proliferation as well as phenotypic differentiation into myofibroblasts suggests that TIMPs may play an important role in tissue repair in the heart that extends beyond their traditional role as MMP inhibitors.

Synthesis and Application of Pyrrolidone-containing Shale Inhibitors

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Immobilization of pectinase from Leucoagaricus gongylophorus on magnetic particles.

PubMed

Adalberto, Paulo Roberto; José dos Santos, Francisco; Golfeto, Camilla Calemi; Costa Iemma, Mônica Rosas; Ferreira de Souza, Dulce Helena; Cass, Quezia Bezerra

2012-10-21

Polygalacturonases (EC 3.2.1.15) hydrolyze the α-1,4-glycosidic linkages in polygalacturonic acid chains. The interest on specific inhibitors of pectinase and the versatility of magnetic support for enzyme immobilization endorsed the preparation of an immobilized enzyme reactor (IMER). This work presents the synthesis of CoFe(2)O(4) amino-derivatives, which was employed as the support for the immobilization of pectinases from Leucoagaricus gongylophorus. Amino-functionalized CoFe(2)O(4) was obtained from glyceryl-derivatized CoFe(2)O(4) and was characterized by infrared spectroscopy and electronic microscopy. The immobilized enzyme maintained the same thermal, chemical and kinetic behaviour of the free enzyme (T(opt) 60 °C; pH(opt) 5.0; K(app)(M) = 0.5 mg min(-1); V(app)(M) ≈ 5.0 μmol min(-1) mL(-1)). The straightforward synthesis of CoFe(2)O(4) derivatives and the efficiency of immobilization offer wide perspectives for the use of the developed new IMER.

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

PubMed

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

2008-01-11

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

Novel inhibitors of IMPDH: a highly potent and selective quinolone-based series.

PubMed

Watterson, Scott H; Carlsen, Marianne; Dhar, T G Murali; Shen, Zhongqi; Pitts, William J; Guo, Junqing; Gu, Henry H; Norris, Derek; Chorba, John; Chen, Ping; Cheney, Daniel; Witmer, Mark; Fleener, Catherine A; Rouleau, Katherine; Townsend, Robert; Hollenbaugh, Diane L; Iwanowicz, Edwin J

2003-02-10

A series of novel quinolone-based small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH) was explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are described.

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

PubMed

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

2009-02-01

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

Synthesis, in vitro and in silico evaluation of novel trans-stilbene analogues as potential COX-2 inhibitors.

PubMed

Regulski, Miłosz; Piotrowska-Kempisty, Hanna; Prukała, Wiesław; Dutkiewicz, Zbigniew; Regulska, Katarzyna; Stanisz, Beata; Murias, Marek

2018-01-01

25 new trans-stilbene and trans-stilbazole derivatives were investigated using in vitro and in silico techniques. The selectivity and potency of the compounds were assessed using commercial ELISA test. The obtained results were incorporated into 2D QSAR assay. The most promising compound 4-nitro-3',4',5'-trihydroxy-trans-stilbene (N1) was synthetized and its potency and selectivity were confirmed. N1 was classified as preferential COX-2 inhibitor. Its ability to inhibit COX-2 in MCF-7 cell line was established and its cytotoxicity by MTT test was assessed. The compound was more cytotoxic than celecoxib within studied concentration range. Finally, the investigated trans-stilbene was docked into COX-1 and COX-2 active sites using "CDOCKER" protocol. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of dibenzodioxazocines and their effects on cholinesterases and muscarinic cholinergic receptors.

PubMed

Gaál, J; Batke, J; Borsodi, A; Rózsa, L; Somogyi, G

1989-01-01

A new family of tricyclic compounds, the dibenzodioxazocines were synthesized. These compounds were the following: 2-chloro-12-(2-piperidino-ethyl)-dibenzo d,g 1,3,6 dioxazocine hydrochloride: EGYT-2347, 2-chloro-12-(3-dimethylamino-2-methyl-propyl)-dibenzo [d,g] [1,3,6]-dibenzodioxazocine hydrochloride: EGYT-2509, 2-chloro-12-(3-dimethylamino-propyl)-dibenzo [d,g] [1,3,6] dioxazocine-maleate: EGYT-2474 and 2-chloro-12-2-(4-methyl-piperazino)-ethyl-dibenzo [d,g] [1,3,6]-dioxazocine-dihydrochloride: EGYT-2541. These compounds are inhibitors of both butyryl- and acetylcholinesterase to and they exhibited relatively good anticholinergic properties in receptor binding experiments. The most selective inhibitor of butyrylcholinesterase is the compound EGYT-2347 (Ki = 1.5 x 10(-7) M) which strongly binds to rat brain muscarinic cholinergic receptor (KD = 4.1 x 10(-8) M).

The mammalian iris-ciliary complex affects organization and synthesis of cytoskeletal proteins of organ and tissue cultured lens epithelial cells.

PubMed

Banerjee, A; Emanuel, K; Parafina, J; Bagchi, M

1992-10-01

A water soluble growth inhibitor was isolated from the mammalian ocular iris-ciliary complex. The molecular weight of this protein is 10 kD or lower as determined by ultrafiltration fractionation. The iris-ciliary (IC) complex water soluble protein(s) significantly inhibits synthesis of lower molecular weight proteins of the epithelial cells of the organ cultured mammalian ocular lens. It was also found that this inhibitory effect of IC is mediated via the structural organization of the lens. Monolayer cultures of the lens epithelial cells exposed to IC did not manifest any inhibition of their protein synthesis. Moreover, these tissue cultured lens epithelial (TCLE) cells showed a significant increase in their protein synthetic activities in response to the presence of IC factors in the culture medium. It is postulated that the IC activity is modulated via either the lens capsule, an extracellular matrix, or due to the specific organization of the intact lens. The specific effects of IC on the cytoskeletal organization and synthesis in the organ cultured lens epithelial (OCLE) and TCLE cells were also examined. Both groups, treated with IC factors, manifested significant alterations in their protein synthetic activities and cytoskeletal architecture. The 3H-leucine incorporation experiments showed that alpha-actin and alpha-tubulin synthesis is partially inhibited by IC factors in OCLE cells but vimentin synthesis is not, whereas in TCLE cells all of them showed increased synthesis in response to IC factors. Turnover rates of these proteins in both OCLE and TCLE cells were also computed. The immunofluorescence and microscopic evaluation of OCLE and TCLE cells exposed to IC factors illustrated significant alteration in the cytoarchitecture of the filaments. We demonstrate that an inhibitor(s) molecule of 10 kD or lower size isolated from IC inhibited protein synthesis of OCLE cells and stimulated protein synthesis in TCLE cells. The IC factor also affects the synthesis and organization of cytoskeletal filaments of both the OCLE and TCLE cells.

Effect of alpha lipoic acid on leukotriene A4 hydrolase.

PubMed

Torres, María José; Fierro, Angélica; Pessoa-Mahana, C David; Romero-Parra, Javier; Cabrera, Gonzalo; Faúndez, Mario

2017-03-15

Leukotriene A 4 hydrolase is a soluble enzyme with epoxide hydrolase and aminopeptidase activities catalysing the conversion of leukotriene A 4 to leukotriene B 4 and the hydrolysis of the peptide proline-glycine-proline. Imbalances in leukotriene B 4 synthesis are related to several pathologic conditions. Currently there are no available drugs capable to modulate the synthesis of leukotriene B 4 or to block its receptors. Here we show the inhibitory profile of alpha lipoic acid on the activity of leukotriene A 4 Hydrolase. Alpha lipoic acid inhibited both activities of the enzyme at concentrations lower than 10μM. The 5-lipoxygenase inhibitor zileuton, or the 5-lipoxygenase activating protein inhibitor MK-886, were unable to inhibit the activity of the enzyme. Acute promyelocytic leukaemia HL-60 cells were differentiated to leukotriene A 4 hydrolase expressing neutrophil-like cells. Alpha lipoic acid inhibited the aminopeptidase activity of the cytosolic fraction from neutrophil-like cells but had no effect on the cytosolic fraction from undifferentiated cells. Docking and molecular dynamic approximations revealed that alpha lipoic acid participates in electrostatic interactions with K-565 and R-563, which are key residues for the carboxylate group recognition of endogenous substrates by the enzyme. Alpha lipoic acid is a compound widely used in clinical practice, most of its therapeutic effects are associated with its antioxidants properties, however, antioxidant effect alone is unable to explain all clinical effects observed with alpha lipoic acid. Our results invite to evaluate the significance of the inhibitory effect of alpha lipoic acid on the catalytic activity of leukotriene A 4 hydrolase using in vivo models. Copyright © 2017 Elsevier B.V. All rights reserved.

PROFLAVINE INHIBITION OF VACCINIA VIRUS SYNTHESIS.

PubMed

BUBEL, H C; WOLFF, D A

1965-04-01

Bubel, H. Curt (University of Cincinnati College of Medicine, Cincinnati, Ohio), and David A. Wolff. Proflavine inhibition of vaccinia virus synthesis. J. Bacteriol. 89:977-983. 1965.-The synthesis of vaccinia virus, hemagglutinin, and blocking antigen, as well as the development of cytopathic effects, were inhibited by low concentrations of proflavine. This inhibitor did not exert a selective effect on any particular portion of the virus synthetic cycle. Proflavine added to infected KB cells during the eclipse period or later stages of virus maturation rapidly arrested further production of infectious virus and virus-related products. Suppression of virus synthesis was completely reversible, indicating that permanent damage to the virus synthetic mechanism did not result from a transient exposure to proflavine. Photosensitization of maturating vaccinia virus by subinhibiting concentrations of proflavine suggested an interaction of the inhibitor with viral nucleic acid.

Proflavine Inhibition of Vaccinia Virus Synthesis

PubMed Central

Bubel, H. Curt; Wolff, David A.

1965-01-01

Bubel, H. Curt (University of Cincinnati College of Medicine, Cincinnati, Ohio), and David A. Wolff. Proflavine inhibition of vaccinia virus synthesis. J. Bacteriol. 89:977–983. 1965.—The synthesis of vaccinia virus, hemagglutinin, and blocking antigen, as well as the development of cytopathic effects, were inhibited by low concentrations of proflavine. This inhibitor did not exert a selective effect on any particular portion of the virus synthetic cycle. Proflavine added to infected KB cells during the eclipse period or later stages of virus maturation rapidly arrested further production of infectious virus and virus-related products. Suppression of virus synthesis was completely reversible, indicating that permanent damage to the virus synthetic mechanism did not result from a transient exposure to proflavine. Photosensitization of maturating vaccinia virus by subinhibiting concentrations of proflavine suggested an interaction of the inhibitor with viral nucleic acid. PMID:14276124

Amide-based inhibitors of p38alpha MAP kinase. Part 2: design, synthesis and SAR of potent N-pyrimidyl amides.

PubMed

Tester, Richland; Tan, Xuefei; Luedtke, Gregory R; Nashashibi, Imad; Schinzel, Kurt; Liang, Weiling; Jung, Joon; Dugar, Sundeep; Liclican, Albert; Tabora, Jocelyn; Levy, Daniel E; Do, Steven

2010-04-15

Optimization of a tri-substituted N-pyridyl amide led to the discovery of a new class of potent N-pyrimidyl amide based p38alpha MAP kinase inhibitors. Initial SAR studies led to the identification of 5-dihydrofuran as an optimal hydrophobic group. Additional side chain modifications resulted in the introduction of hydrogen bond interactions. Through extensive SAR studies, analogs bearing free amino groups and alternatives to the parent (S)-alpha-methyl benzyl moiety were identified. These compounds exhibited improved cellular activities and maintained balance between p38alpha and CYP3A4 inhibition. Copyright 2010 Elsevier Ltd. All rights reserved.

Kynurenine 3-mono-oxygenase inhibitors attenuate post-ischemic neuronal death in organotypic hippocampal slice cultures.

PubMed

Carpenedo, Raffaella; Meli, Elena; Peruginelli, Fiamma; Pellegrini-Giampietro, Domenico E; Moroni, Flavio

2002-09-01

Kynurenine 3-mono-oxygenase (KMO) inhibitors reduce 3-hydroxykynurenine (3-HK) and quinolinic acid (QUIN) neosynthesis and facilitate kynurenine metabolism towards kynurenic acid (KYNA) formation. They also reduce tissue damage in models of focal or transient global cerebral ischemia in vivo. We used organotypic hippocampal slice cultures exposed to oxygen and glucose deprivation (OGD) to investigate KMO mechanism(s) of neuroprotective activity. Exposure of the slices to 30 min of OGD caused CA1 pyramidal cell death and significantly decreased the amount of KYNA released in the incubation medium. The KMO inhibitors (m-nitrobenzoyl)-alanine (30-100 micro m) or 3,4-dimethoxy-[-N-4-(nitrophenyl)thiazol-2yl]-benzenesulfonamide (1-10 micro m) reduced post-ischemic neuronal death and increased KYNA concentrations in slice incubation media. The maximal concentration of KYNA detected in the incubation media of slices treated with KMO inhibitors was approximately 50 nm and was too low to efficiently interact with alpha7 nicotinic acetylcholine receptors or with the glycineb site of N-methyl-d-aspartate (NMDA) receptors. On the other hand, the addition of either 3-HK or QUIN (1-10 micro m) to OGD-exposed hippocampal slices prevented the neuroprotective activity of KMO inhibitors. Our results suggest that KMO inhibitors reduce the neuronal death found in the CA1 region of organotypic hippocampal slices exposed to 30 min of OGD by decreasing the local synthesis of 3-HK and QUIN.

Small-Molecule Inhibitors of the MDM2–p53 Protein–Protein Interaction (MDM2 Inhibitors) in Clinical Trials for Cancer Treatment

PubMed Central

2015-01-01

Design of small-molecule inhibitors (MDM2 inhibitors) to block the MDM2–p53 protein–protein interaction has been pursued as a new cancer therapeutic strategy. In recent years, potent, selective, and efficacious MDM2 inhibitors have been successfully obtained and seven such compounds have been advanced into early phase clinical trials for the treatment of human cancers. Here, we review the design, synthesis, properties, preclinical, and clinical studies of these clinical-stage MDM2 inhibitors. PMID:25396320

Luteolin, a flavonoid, inhibits AP-1 activation by basophils.

PubMed

Hirano, Toru; Higa, Shinji; Arimitsu, Junsuke; Naka, Tetsuji; Ogata, Atsushi; Shima, Yoshihito; Fujimoto, Minoru; Yamadori, Tomoki; Ohkawara, Tomoharu; Kuwabara, Yusuke; Kawai, Mari; Matsuda, Hisashi; Yoshikawa, Masayuki; Maezaki, Naoyoshi; Tanaka, Tetsuaki; Kawase, Ichiro; Tanaka, Toshio

2006-02-03

Flavonoids including luteolin, apigenin, and fisetin are inhibitors of IL-4 synthesis and CD40 ligand expression by basophils. This study was done to search for compounds with greater inhibitory activity of IL-4 expression and to clarify the molecular mechanisms through which flavonoids inhibit their expression. Of the 37 flavonoids and related compounds examined, ayanin, luteolin, and apigenin were the strongest inhibitors of IL-4 production by purified basophils in response to anti-IgE antibody plus IL-3. Luteolin did not suppress Syk or Lyn phosphorylation in basophils, nor did suppress p54/46 SAPK/JNK, p38 MAPK, and p44/42 MAPK activation by a basophilic cell line, KU812 cells, stimulated with A23187 and PMA. However, luteolin did inhibit phosphorylation of c-Jun and DNA binding activity of AP-1 in nuclear lysates from stimulated KU812 cells. These results provide a fundamental structure of flavonoids for IL-4 inhibition and demonstrate a novel action of flavonoids that suppresses the activation of AP-1.

Novel N-allyl/propargyl tetrahydroquinolines: Synthesis via Three-component Cationic Imino Diels-Alder Reaction, Binding Prediction, and Evaluation as Cholinesterase Inhibitors.

PubMed

Rodríguez, Yeray A; Gutiérrez, Margarita; Ramírez, David; Alzate-Morales, Jans; Bernal, Cristian C; Güiza, Fausto M; Romero Bohórquez, Arnold R

2016-10-01

New N-allyl/propargyl 4-substituted 1,2,3,4-tetrahydroquinolines derivatives were efficiently synthesized using acid-catalyzed three components cationic imino Diels-Alder reaction (70-95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl-cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC50 = 72 μm) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl-cholinesterase was exhibited by compound 4ae (IC50 = 25.58 μm) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl-cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets. © 2016 The Authors Chemical Biology & Drug Design Published by John Wiley & Sons Ltd.

Transcriptomic analysis of mouse EL4 T cells upon T cell activation and in response to protein synthesis inhibition via cycloheximide treatment.

PubMed

Lim, Pek Siew; Hardy, Kristine; Peng, Kaiman; Shannon, Frances M

2016-03-01

T cell activation involves the recognition of a foreign antigen complexed to the major histocompatibility complex on the antigen presenting T cell to the T cell receptor. This leads to activation of signaling pathways, which ultimately leads to induction of key cytokine genes responsible for eradication of foreign antigens. We used the mouse EL4 T cell as a model system to study genes that are induced as a result of T cell activation using phorbol myristate acetate (PMA) and calcium ionomycin (I) as stimuli. We were also interested to examine the importance of new protein synthesis in regulating the expression of genes involved in T cell activation. Thus we have pre-treated mouse EL4 T cells with cycloheximide, a protein synthesis inhibitor, and left the cells unstimulated or stimulated with PMA/I for 4 h. We performed microarray expression profiling of these cells to correlate the gene expression with chromatin state of T cells upon T cell activation [1]. Here, we detail further information and analysis of the microarray data, which shows that T cell activation leads to differential expression of genes and inducible genes can be further classified as primary and secondary response genes based on their protein synthesis dependency. The data is available in the Gene Expression Omnibus under accession number GSE13278.

Synthesis of empagliflozin, a novel and selective sodium-glucose co-transporter-2 inhibitor, labeled with carbon-14 and carbon-13.

PubMed

Hrapchak, Matt; Latli, Bachir; Wang, Xiao-Jun; Lee, Heewon; Campbell, Scot; Song, Jinhua J; Senanayake, Chris H

2014-10-01

Empagliflozin, (2S,3R,4R,5S,6R)-2-[4-chloro-3-[[4-[(3S)-oxolan-3-yl]oxyphenyl]methyl]phenyl]-6-(hydroxymethyl)oxane-3,4,5-triol was recently approved by the FDA for the treatment of chronic type 2 diabetes mellitus. Herein, we report the synthesis of carbon-13 and carbon-14 labeled empagliflozin. Carbon-13 labeled empagliflozin was prepared in five steps and in 34% overall chemical yield starting from the commercially available α-D-glucose-[(13)C6]. For the radiosynthesis, the carbon-14 atom was introduced in three different positions of the molecule. In the first synthesis, Carbon-14 D-(+)-gluconic acid δ-lactone was used to prepare specifically labeled empagliflozin in carbon-1 of the sugar moiety in four steps and in 19% overall radiochemical yield. Carbon-14 labeled empagliflozin with the radioactive atom in the benzylic position was obtained in eight steps and in 7% overall radiochemical yield. In the last synthesis carbon-14 uniformly labeled phenol was used to give [(14)C]empagliflozin in eight steps and in 18% overall radiochemical yield. In all these radiosyntheses, the specific activities of the final compounds were higher than 53 mCi/mmol, and the radiochemical purities were above 98.5%. Copyright © 2014 John Wiley & Sons, Ltd.

Chemoenzymatic Synthesis and α-Glucosidase Inhibitory Activity of Dimeric Neolignans Inspired by Magnolol.

PubMed

Pulvirenti, Luana; Muccilli, Vera; Cardullo, Nunzio; Spatafora, Carmela; Tringali, Corrado

2017-05-26

A chemoenzymatic synthesis of a small library of dimeric neolignans inspired by magnolol (1) is reported. The 2-iodoxybenzoic acid (IBX)-mediated regioselective ortho-hydroxylation of magnolol is described, affording the bisphenols 6 and 7. Further magnolol analogues (12, 13, 15-17, 19-23) were obtained from eugenol (3), tyrosol (4), and homovanillic alcohol (5), through horseradish peroxidase (HRP)-mediated oxidative coupling and regioselective ortho-hydroxylation or ortho-demethylation in the presence of IBX, followed by reductive treatment with Na 2 S 2 O 4 . A chemoselective protection/deprotection of the alcoholic group of 4 and 5 was carried out by lipase-mediated acetylation/deacetylation. The dimeric neolignans, together with 1 and honokiol (2), were evaluated as inhibitors of yeast α-glucosidase, in view of their possible utilization and optimization as antidiabetic drugs. The synthetic analogues of magnolol showed a strong inhibitory activity with IC 50 values in the range 0.15-4.1 μM, much lower than those of honokiol and the reference compounds quercetin and acarbose. In particular, a very potent inhibitory activity, with an IC 50 of 0.15 μM, was observed for 1,1'-dityrosol-8,8'-diacetate (15), and comparable inhibitory activities were also shown by bisphenols 6 (0.49 μM), 13 (0.50 μM), and 22 (0.86 μM). A kinetic study showed that 15 acts as a competitive inhibitor, with a K i value of 0.86 μM.

Synthesis and evaluation of poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene)/magnetite nanoparticle composites as corrosion inhibitors for steel.

PubMed

El-Mahdy, Gamal A; Atta, Ayman M; Al-Lohedan, Hamad A

2014-01-30

Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene)/magnetite (PAMPS-Na-co-St/Fe3O4) were prepared by emulsifier-free miniemulsion polymerization using styrene (St) as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na) as an ionic comonomer, N,N-methylenebisacrylamide (MBA) as crosslinker, hexadecane (HD) as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN) as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM). The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA). The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

Synthesis and biological evaluation of 5-carbamoyl-2-phenylpyrimidine derivatives as novel and potent PDE4 inhibitors.

PubMed

Goto, Taiji; Shiina, Akiko; Yoshino, Toshiharu; Mizukami, Kiyoshi; Hirahara, Kazuki; Suzuki, Osamu; Sogawa, Yoshitaka; Takahashi, Tomoko; Mikkaichi, Tsuyoshi; Nakao, Naoki; Takahashi, Mizuki; Hasegawa, Masashi; Sasaki, Shigeki

2013-11-15

5-Carbamoyl-2-phenylpyrimidine derivative 2 has been identified as a phosphodiesterase 4 (PDE4) inhibitor with moderate PDE4B inhibitory activity (IC50=200 nM). Modification of the carboxylic acid moiety of 2 gave N-neopentylacetamide derivative 10f, which had high in vitro PDE4B inhibitory activity (IC50=8.3 nM) and in vivo efficacy against lipopolysaccharide (LPS)-induced pulmonary neutrophilia in mice (ID50=16 mg/kg, ip). Furthermore, based on the X-ray crystallography of 10f bound to the human PDE4B catalytic domain, we designed 7,8-dihydro-6H-pyrido[4,3-d]pyrimidin-5-one derivative 39 which has a fused bicyclic lactam scaffold. Compound 39 exhibited excellent inhibitory activity against LPS-induced tumor necrosis factor alpha (TNF-α) production in mouse splenocytes (IC50=0.21 nM) and in vivo anti-inflammatory activity against LPS-induced pulmonary neutrophilia in mice (41% inhibition at a dose of 1.0 mg/kg, i.t.). Copyright © 2013 Elsevier Ltd. All rights reserved.

Sildenafil Stimulates the Expression of Gaseous Monoxide-Generating Enzymes in Vascular Smooth Muscle Cells via Distinct Signaling Pathways

PubMed Central

Liu, Xiao-ming; Peyton, Kelly J.; Wang, Xinhui; Durante, William

2012-01-01

Sildenafil is a cGMP-specific phosphodiesterase type 5 inhibitor that augments cGMP accumulation following the activation of soluble guanylate cyclase (sGC). In this study, we investigated whether sildenafil promotes the production of the sGC-stimulatory gases, carbon monoxide and nitric oxide, by stimulating the expression of the inducible isoforms of heme oxygenase (HO-1) and nitric oxide synthase (iNOS) in vascular smooth muscle cells (SMCs). Sildenafil increased HO-1 expression and potentiated cytokine-mediated expression of iNOS and NO synthesis by SMCs. The induction of HO-1 was unaffected by the sGC inhibitor 1H-(1,2,4)oxadiazolo[4,3-α]quinozalin-1-one (ODQ) or the (9S,10R,12R)-2,3,9,10,11,12-hexahydro-10-methoxy-2,9-dimethyl-1-oxo-9,12-epoxy-1H-diindol91,2,3-fg:3′,2′,1′-kl)pyrrolo(3,4-i)benzodiazocine-10-carboxylic acid, methyl ester (KT 5823). However, the sildenafil-mediated increase in HO-1 promoter activity was abolished by mutating the antioxidant responsive elements in the promoter or by overexpressing a dominant-negative mutant of NF-E2-related factor-2 (Nrf2). Furthermore, the induction of HO-1 by sildenafil was accompanied by an increase in reactive oxygen species (ROS) and blocked by N-acetyl-L-cysteine and rotenone. In contrast, the enhancement of cytokine-stimulated NO synthesis by sildenafil was prevented by ODQ and the protein kinase A inhibitor (9S,10S,12R)-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo(1,2,3-fg:3′,2′,1′-kl)pyrrolo(3,4-i)(1,6)benzodiazocine-10-carboxylic acid hexyl ester (KT 5720) and duplicated by lipophilic analogues of cGMP. In conclusion, these studies demonstrate that sildenafil stimulates the expression of HO-1 and iNOS via the ROS-Nrf2 and sGC-cGMP pathway, respectively. The ability of sildenafil to block the catabolism of cGMP while stimulating the synthesis of sGC-stimulatory gaseous monoxides through the induction of HO-1 and iNOS provides a potent mechanism by which cGMP-dependent vascular actions of this drug are amplified. PMID:22864061

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

PubMed Central

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

2015-01-01

We have used an unbiased proteomic profiling strategy to identify new potential therapeutic targets in tumor-initiating cells (TICs), a.k.a., cancer stem cells (CSCs). Towards this end, the proteomes of mammospheres from two breast cancer cell lines were directly compared to attached monolayer cells. This allowed us to identify proteins that were highly over-expressed in CSCs and/or progenitor cells. We focused on ribosomal proteins and protein folding chaperones, since they were markedly over-expressed in mammospheres. Overall, we identified >80 molecules specifically associated with protein synthesis that were commonly upregulated in mammospheres. Most of these proteins were also transcriptionally upregulated in human breast cancer cells in vivo, providing evidence for their potential clinical relevance. As such, increased mRNA translation could provide a novel mechanism for enhancing the proliferative clonal expansion of TICs. The proteomic findings were functionally validated using known inhibitors of protein synthesis, via three independent approaches. For example, puromycin (which mimics the structure of tRNAs and competitively inhibits protein synthesis) preferentially targeted CSCs in both mammospheres and monolayer cultures, and was ~10-fold more potent for eradicating TICs, than “bulk” cancer cells. In addition, rapamycin, which inhibits mTOR and hence protein synthesis, was very effective at reducing mammosphere formation, at nanomolar concentrations. Finally, mammosphere formation was also markedly inhibited by methionine restriction, which mimics the positive effects of caloric restriction in cultured cells. Remarkably, mammosphere formation was >18-fold more sensitive to methionine restriction and replacement, as directly compared to monolayer cell proliferation. Methionine is absolutely required for protein synthesis, since every protein sequence starts with a methionine residue. Thus, the proliferation and survival of CSCs is very sensitive to the inhibition of protein synthesis, using multiple independent approaches. Our findings have important clinical implications, since they may also explain the positive therapeutic effects of PI3-kinase inhibitors and AKT inhibitors, as they ultimately converge on mTOR signaling and would block protein synthesis. We conclude that inhibition of mRNA translation by pharmacological or protein/methionine restriction may be effective strategies for eliminating TICs. Our data also indicate a novel mechanism by which caloric/protein restriction may reduce tumor growth, by targeting protein synthesis in anabolic tumor-initiating cancer cells. PMID:25671304

(7-Diethylaminocoumarin-4-yl)methyl ester of suberoylanilide hydroxamic acid as a caged inhibitor for photocontrol of histone deacetylase activity.

PubMed

Ieda, Naoya; Yamada, Sota; Kawaguchi, Mitsuyasu; Miyata, Naoki; Nakagawa, Hidehiko

2016-06-15

Histone deacetylases (HDACs) are involved in epigenetic control of the expression of various genes by catalyzing deacetylation of ε-acetylated lysine residues. Here, we report the design, synthesis and evaluation of the (7-diethylaminocoumarin-4-yl)methyl ester of suberoylanilide hydroxamic acid (AC-SAHA) as a caged HDAC inhibitor, which releases the known pan-HDAC inhibitor SAHA upon cleavage of the photolabile (7-diethylaminocoumarin-4-yl)methyl protecting group in response to photoirradiation. A key advantage of AC-SAHA is that the caged derivative itself shows essentially no HDAC-inhibitory activity. Upon photoirradiation, AC-SAHA decomposes to SAHA and a 7-diethylaminocoumarin derivative, together with some minor products. We confirmed that AC-SAHA inhibits HDAC in response to photoirradiation in vitro by means of chemiluminescence assay. AC-SAHA also showed photoinduced inhibition of proliferation of human colon cancer cell line HCT116, as determined by MTT assay. Thus, AC-SAHA should be a useful tool for spatiotemporally controlled inhibition of HDAC activity, as well as a candidate chemotherapeutic reagent for human colon cancer. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Oxime-based linker libraries as a general approach for the rapid generation and screening of multidentate inhibitors

PubMed Central

Bahta, Medhanit; Liu, Fa; Kim, Sung-Eun; Stephen, Andrew G.; Fisher, Robert J.; Burke, Terrence R.

2013-01-01

The described oxime-based library protocol provides detailed procedures for the linkage of aminooxy functionality with aldehyde building blocks that result in the generation of libraries of multidentate inhibitors. Synthesis of inhibitors for protein tyrosine phosphatases (PTPs) and antagonists directed against the human tumor susceptibility gene 101 (Tsg101) are shown as examples. Three steps are involved: a) the design and synthesis of aminooxy platforms; b) tethering with aldehydes to form oxime-based linkages with sufficient purity; and c) direct in vitro biological evaluation of oxime products without purification. Each coupling reaction is a) performed in capped microtubes at room temperature; b) diluted for inhibitory evaluation and c) screened with targets in microplates to provide IC50 or Kd values. The synthesis of the aminooxy platforms takes 3–5 days; tethering with the aldehydes takes 24 h; and inhibition assay of enzymes and protein-protein interactions (PPIs) takes 30 min and 2 h respectively. PMID:22422315

SREBP cleavage-activating protein (SCAP) is required for increased lipid synthesis in liver induced by cholesterol deprivation and insulin elevation

PubMed Central

Matsuda, Morihiro; Korn, Bobby S.; Hammer, Robert E.; Moon, Young-Ah; Komuro, Ryutaro; Horton, Jay D.; Goldstein, Joseph L.; Brown, Michael S.; Shimomura, Iichiro

2001-01-01

In liver, the synthesis of cholesterol and fatty acids increases in response to cholesterol deprivation and insulin elevation, respectively. This regulatory mechanism underlies the adaptation to cholesterol synthesis inhibitors (statins) and high calorie diets (insulin). In nonhepatic cells, lipid synthesis is controlled by sterol regulatory element-binding proteins (SREBPs), membrane-bound transcription factors whose active domains are released proteolytically to enter the nucleus and activate genes involved in the synthesis and uptake of cholesterol and fatty acids. SCAP (SREBP cleavage-activating protein) is a sterol-regulated escort protein that transports SREBPs from their site of synthesis in the endoplasmic reticulum to their site of cleavage in the Golgi. Here, we produced a conditional deficiency of SCAP in mouse liver by genomic recombination mediated by inducible Cre recombinase. SCAP-deficient mice showed an 80% reduction in basal rates of cholesterol and fatty acid synthesis in liver, owing to decreases in mRNAs encoding multiple biosynthetic enzymes. Moreover, these mRNAs failed to increase normally in response to cholesterol deprivation produced by a cholesterol synthesis inhibitor and to insulin elevation produced by a fasting–refeeding protocol. These data provide in vivo evidence that SCAP and the SREBPs are required for hepatic lipid synthesis under basal and adaptive conditions. PMID:11358865

Glutamine drives glutathione synthesis and contributes to radiation sensitivity of A549 and H460 lung cancer cell lines

PubMed Central

Sappington, Daniel R.; Siegel, Eric R.; Hiatt, Gloria; Desai, Abhishek; Penney, Rosalind B.; Jamshidi-Parsian, Azemat; Griffin, Robert J.; Boysen, Gunnar

2016-01-01

Background Increased glutamine uptake is known to drive cancer cell proliferation, making tumor cells glutamine-dependent. Glutamine provides additional carbon and nitrogen sources for cell growth. The first step in glutamine utilization is its conversion to glutamate by glutaminase (GLS). Glutamate is a precursor for glutathione synthesis, and we investigated the hypothesis that glutamine drives glutathione synthesis and thereby contributes to cellular defense systems. Methods The importance of glutamine for glutathione synthesis was studied in H460 and A549 lung cancer cell lines using glutamine-free medium and Bis-2-(5-phenyl-acetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (BPTES) a GLS inhibitor. Metabolic activities were determined by targeted mass spectrometry. Results A significant correlation between glutamine consumption and glutathione excretion was demonstrated in H460 and A549 tumor cells. Culturing in the presence of [13C5]glutamine demonstrated that by 12 hrs >50% of excreted glutathione is derived from glutamine. Culturing in glutamine-free medium or treatment with BPTES, a glutaminase (GLS)-specific inhibitor, reduced cell proliferation and viability, and abolished glutathione excretion. Treatment with glutathione-ester prevented BPTES induced cytotoxicity. Inhibition of GLS markedly radiosensitized the lung tumor cell lines, suggesting an important role of glutamine-derived glutathione in determining radiation sensitivity. Conclusions We demonstrate here for the first time that a significant amount of extracellular glutathione is directly derived from glutamine. This finding adds yet another important function to the already known glutamine dependence of tumor cells and probably tumors as well. General significance Glutamine is essential for synthesis and excretion of glutathione to promote cell growth and viability. PMID:26825773

Investigating Genomic Mechanisms of Treatment Resistance in Castration Resistant Prostate Cancer

DTIC Science & Technology

2013-05-01

warranting an elevated dose (1000mg twice daily). Blood is currently being collected for serum hormone levels , SNPs in androgen synthesis genes...Summary 3 . DATES COVERED 1 May 2012 – 30 April 2013 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Investigating Genomic Mechanisms of Treatment...to Androgen Biosynthesis Inhibitors in Men with Metastatic Castration Resistant Prostate Cancer. Notice of IRB approval. 3 . Curriculum Vitae

Developing Memory Reconsolidation Blockers as Novel PTSD Treatments

DTIC Science & Technology

2010-06-01

haloperidol , and the protein- synthesis inhibitor rapamycin all reduce reconsolidation of a cue-conditioned fear response in rats, although none of these is...used in this study. 2.1.2.4. Haloperidol . Next we decided to explore another candidate drug, the dopaminergic antagonist haloperidol . We...tested the ability of haloperidol (1mg/kg) to block reconsolidation, either alone or in combination with propranolol (10 mg/kg) in male and female

Pre-clinical pharmacology of AZD3965, a selective inhibitor of MCT1: DLBCL, NHL and Burkitt’s lymphoma anti-tumor activity

PubMed Central

Curtis, Nicola J.; Mooney, Lorraine; Hopcroft, Lorna; Michopoulos, Filippos; Whalley, Nichola; Zhong, Haihong; Murray, Clare; Logie, Armelle; Revill, Mitchell; Byth, Kate F.; Benjamin, Amanda D.; Firth, Mike A.; Green, Stephen; Smith, Paul D.; Critchlow, Susan E.

2017-01-01

Tumors frequently display a glycolytic phenotype with increased flux through glycolysis and concomitant synthesis of lactate. To maintain glycolytic flux and prevent intracellular acidification, tumors efflux lactate via lactate transporters (MCT1-4). Inhibitors of lactate transport have the potential to inhibit glycolysis and tumor growth. We developed a small molecule inhibitor of MCT1 (AZD3965) and assessed its activity across a panel of cell lines. We explored its antitumor activity as monotherapy and in combination with doxorubicin or rituximab. AZD3965 is a potent inhibitor of MCT1 with activity against MCT2 but selectivity over MCT3 and MCT4. In vitro, AZD3965 inhibited the growth of a range of cell lines especially haematological cells. Inhibition of MCT1 by AZD3965 inhibited lactate efflux and resulted in accumulation of glycolytic intermediates. In vivo, AZD3965 caused lactate accumulation in the Raji Burkitt’s lymphoma model and significant tumor growth inhibition. Moreover, AZD3965 can be combined with doxorubicin or rituximab, components of the R-CHOP standard-of-care in DLBCL and Burkitt’s lymphoma. Finally, combining lactate transport inhibition by AZD3965 with GLS1 inhibition in vitro, enhanced cell growth inhibition and cell death compared to monotherapy treatment. The ability to combine AZD3965 with novel, and standard-of-care inhibitors offers novel combination opportunities in haematological cancers. PMID:29050199

Pre-clinical pharmacology of AZD3965, a selective inhibitor of MCT1: DLBCL, NHL and Burkitt's lymphoma anti-tumor activity.

PubMed

Curtis, Nicola J; Mooney, Lorraine; Hopcroft, Lorna; Michopoulos, Filippos; Whalley, Nichola; Zhong, Haihong; Murray, Clare; Logie, Armelle; Revill, Mitchell; Byth, Kate F; Benjamin, Amanda D; Firth, Mike A; Green, Stephen; Smith, Paul D; Critchlow, Susan E

2017-09-19

Tumors frequently display a glycolytic phenotype with increased flux through glycolysis and concomitant synthesis of lactate. To maintain glycolytic flux and prevent intracellular acidification, tumors efflux lactate via lactate transporters (MCT1-4). Inhibitors of lactate transport have the potential to inhibit glycolysis and tumor growth. We developed a small molecule inhibitor of MCT1 (AZD3965) and assessed its activity across a panel of cell lines. We explored its antitumor activity as monotherapy and in combination with doxorubicin or rituximab. AZD3965 is a potent inhibitor of MCT1 with activity against MCT2 but selectivity over MCT3 and MCT4. In vitro , AZD3965 inhibited the growth of a range of cell lines especially haematological cells. Inhibition of MCT1 by AZD3965 inhibited lactate efflux and resulted in accumulation of glycolytic intermediates. In vivo , AZD3965 caused lactate accumulation in the Raji Burkitt's lymphoma model and significant tumor growth inhibition. Moreover, AZD3965 can be combined with doxorubicin or rituximab, components of the R-CHOP standard-of-care in DLBCL and Burkitt's lymphoma. Finally, combining lactate transport inhibition by AZD3965 with GLS1 inhibition in vitro , enhanced cell growth inhibition and cell death compared to monotherapy treatment. The ability to combine AZD3965 with novel, and standard-of-care inhibitors offers novel combination opportunities in haematological cancers.

The chemistry of nicotinamide adenine dinucleotide (NAD) analogues containing C-nucleosides related to nicotinamide riboside.

PubMed

Pankiewicz, Krzysztof W; Watanabe, Kyoichi A; Lesiak-Watanabe, Krystyna; Goldstein, Barry M; Jayaram, Hiremagalur N

2002-04-01

Oncolytic C-nucleosides, tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide) and benzamide riboside (3-beta-D-ribofuranosylbenzamide) are converted in cell into active metabolites thiazole-4-carboxamide- and benzamide adenine dinucleotide, TAD and BAD, respectively. TAD and BAD as NAD analogues were found to bind at the nicotinamide adenine dinucleotide (cofactor NAD) site of inosine monophosphate dehydrogenase (IMPDH), an important target in cancer treatment. The synthesis and evaluation of anticancer activity of a number of C-nucleosides related to tiazofurin and nicotinamide riboside then followed and are reviewed herein. Interestingly, pyridine C-nucleosides (such as C-nicotinamide riboside) are not metabolized into the corresponding NAD analogues in cell. Their conversion by chemical methods is described. As dinucleotides these compounds show inhibition of IMPDH in low micromolar level. Also, the synthesis of BAD in metabolically stable bis(phosphonate) form is discussed indicating the usefulness of such preformed inhibitors in drug development. Among tiazofurin analogues, Franchetti and Grifantini found, that the replacement of the sulfur by oxygen (as in oxazafurin) but not the removal of nitrogen (tiophenfurin) of the thiazole ring resulted in inactive compounds. The anti cancer activity of their synthetic dinucleotide analogues indicate that inactive compounds are not only poorly metabolized in cell but also are weak inhibitors of IMPDH as dinucleotides.

Synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid vinyl-ACCA) derivatives: key intermediates for the preparation of inhibitors of the hepatitis C virus NS3 protease.

PubMed

Beaulieu, Pierre L; Gillard, James; Bailey, Murray D; Boucher, Colette; Duceppe, Jean-Simon; Simoneau, Bruno; Wang, Xiao-Jun; Zhang, Li; Grozinger, Karl; Houpis, Ioannis; Farina, Vittorio; Heimroth, Heidi; Krueger, Thomas; Schnaubelt, Jürgen

2005-07-22

(1R,2S)-1-Amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is a key building block in the synthesis of potent inhibitors of the hepatitis C virus NS3 protease such as BILN 2061, which was recently shown to dramatically reduce viral load after administration to patients infected with HCV genotype 1. We have developed a scalable process that delivers derivatives of this unusual amino acid in >99% ee. The strategy was based on the dialkylation of a glycine Schiff base using trans-1,4-dibromo-2-butene as an electrophile to produce racemic vinyl-ACCA, which was subsequently resolved using a readily available, inexpensive esterase enzyme (Alcalase 2.4L). Factors that affect diastereoselection in the initial dialkylation steps were examined and the conditions optimized to deliver the desired diastereomer selectively. Product inhibition, which was encountered during the enzymatic resolution step, initially resulted in prolonged cycle times. Enrichment of racemic vinyl-ACCA through a chemical resolution via diastereomeric salt formation or the use of forcing conditions in the enzymatic reaction both led to improvements in throughput and the development of a viable process. The chemistry described herein was scaled up to produce multikilogram quantities of this building block.

Synthesis, spectroscopic characterization and a comparative study of the corrosion inhibitive efficiency of an α-aminophosphonate and Schiff base derivatives: Experimental and theoretical investigations

NASA Astrophysics Data System (ADS)

Benbouguerra, Khalissa; Chafaa, Salah; Chafai, Nadjib; Mehri, Mouna; Moumeni, Ouahiba; Hellal, Abdelkader

2018-04-01

New α-aminophosphonate (α-APD) and Schiff base (E-NDPIMA) derivatives have been prepared and their structures ware proved by IR, UV-Vis, 1H, 13C and 31P NMR spectroscopy. Their inhibitive capacities on the XC48 carbon steel corrosion in 0.5 mol L-1 H2SO4 solution were explored by weight loss, Tafel polarization, electrochemical impedance spectroscopy (EIS) and atomic force microscope (AFM). Experimental results illustrate that the synthesized compounds are an effectives inhibitors and the adsorption of inhibitors molecules on the carbon steel surface obeys Langmuir adsorption isotherm. In addition, quantum chemical calculations performed with density function theory (DFT) method have been used to correlate the inhibition efficiency established experimentally. Also, the molecular dynamics simulations have been utilized to simulate the interactions between the inhibitors molecules and Fe (100) surface in aqueous solution.

Discovery of new nanomolar inhibitors of GPa: Extension of 2-oxo-1,2-dihydropyridinyl-3-yl amide-based GPa inhibitors.

PubMed

Loughlin, Wendy A; Jenkins, Ian D; Karis, N David; Healy, Peter C

2017-02-15

Glycogen Phosphorylase (GP) is a functionally active dimeric enzyme, which is a target for inhibition of the conversion of glycogen to glucose-1-phosphate. In this study we report the design and synthesis of 14 new pyridone derivatives, and seek to extend the SAR analysis of these compounds. The SAR revealed the minor influence of the amide group, importance of the pyridone ring both spatially around the pyridine ring and for possible π-stacking, and confirmed a preference for inclusion of 3,4-dichlorobenzyl moieties, as bookends to the pyridone scaffold. Upon exploring a dimer strategy as part of the SAR analysis, the first extended 2-oxo-dihydropyridinyl-3-yl amide nanomolar based inhibitors of GPa (IC 50  = 230 and 260 nM) were identified. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

PubMed

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

2015-01-01

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

Discovery of imidazopyridine derivatives as novel c-Met kinase inhibitors: Synthesis, SAR study, and biological activity.

PubMed

Yang, Yifei; Zhang, Yuan; Yang, LingYun; Zhao, Leilei; Si, Lianghui; Zhang, Huibin; Liu, Qingsong; Zhou, Jinpei

2017-02-01

Receptor tyrosine kinase c-Met acts as an alternative angiogenic pathway in the process and contents of cancers. A series of imidazopyridine derivatives were designed and synthesized according to the established docking studies as possible c-Met inhibitors. Most of these imidazopyridine derivatives displayed nanomolar potency against c-Met in both biochemical enzymatic screens and cellular pharmacology studies. Especially, compound 7g exhibited the most inhibitory activity against c-Met with IC 50 of 53.4nM and 253nM in enzymatic and cellular level, respectively. Following that, the compound 7g was docked into the protein of c-Met and the structure-activity relationship was analyzed in detail. These findings indicated that the novel imidazopyridine derivative compound 7g was a potential c-Met inhibitor deserving further investigation for cancer treatment. Copyright © 2016. Published by Elsevier Inc.

Design and Synthesis of Novel and Selective Glycine Transporter-1 (GlyT1) Inhibitors with Memory Enhancing Properties.

PubMed

Santora, Vincent J; Almos, Theresa A; Barido, Richard; Basinger, Jillian; Bellows, Chris L; Bookser, Brett Carder; Breitenbucher, J Guy; Broadbent, Nicola J; Cabebe, Clifford; Chai, Chih-Kun; Chen, Mi; Chow, Stephine; Chung, De Michael; Crickard, Lindsay; Danks, Anne M; Freestone, Graeme; Gitnick, Dany; Gupta, Varsha; Hoffmaster, Christine; Hudson, Andrew R; Kaplan, Alan P; Kennedy, Michael R; Lee, Dong; Limberis, James; Ly, Kiev; Mak, Chi Ching; Masatsugu, Brittany; Morse, Andrew C; Na, Jim; Neul, David; Nikpur, John; Peters, Marco; Petroski, Robert E; Renick, Joel; Sebring, Kristen; Sevidal, Samantha; Tabatabaei, Ali; Wen, Jenny; Yan, Yingzhuo; Yoder, Zachary W; Zook, Douglas

2018-06-11

We report here the identification and optimization of a novel series of potent GlyT1 inhibitors. A ligand design campaign that utilized known GlyT1 inhibitors as starting points led to the identification of a novel series of pyrrolo[3,4-c]pyrazoles amides (21-50) with good in vitro potency. Subsequent optimization of physicochemical and in vitro ADME properties produced several compounds with promising pharmacokinetic profiles. In vivo inhibition of GlyT1 was demonstrated for select compounds within this series by measuring the elevation of glycine in the cerebrospinal fluid (CSF) of rats after a single oral dosing of 10 mg/kg. Ultimately, an optimized lead, compound 46, demonstrated in vivo efficacy in a rat Novel Object Recognition (NOR) assay after oral dosing at 0.1, 1, and 3 mg/kg.

Design, synthesis and evaluation of a potent substrate analog inhibitor identified by scanning Ala/Phe mutagenesis, mimicking substrate co-evolution, against multidrug-resistant HIV-1 protease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yedidi, Ravikiran S.; Muhuhi, Joseck M.; Liu, Zhigang

Highlights: •Inhibitors against MDR HIV-1 protease were designed, synthesized and evaluated. •Lead peptide (6a) showed potent inhibition (IC{sub 50}: 4.4 nM) of MDR HIV-1 protease. •(6a) Showed favorable binding isotherms against NL4-3 and MDR proteases. •(6a) Induced perturbations in the {sup 15}N-HSQC spectrum of MDR HIV-1 protease. •Molecular modeling suggested that (6a) may induce total flap closure inMDR protease. -- Abstract: Multidrug-resistant (MDR) clinical isolate-769, human immunodeficiency virus type-1 (HIV-1) protease (PDB ID: (1TW7)), was shown to exhibit wide-open flaps and an expanded active site cavity, causing loss of contacts with protease inhibitors. In the current study, the expanded activemore » site cavity of MDR769 HIV-1 protease was screened with a series of peptide-inhibitors that were designed to mimic the natural substrate cleavage site, capsid/p2. Scanning Ala/Phe chemical mutagenesis approach was incorporated into the design of the peptide series to mimic the substrate co-evolution. Among the peptides synthesized and evaluated, a lead peptide (6a) with potent activity (IC{sub 50}: 4.4 nM) was identified against the MDR769 HIV-1 protease. Isothermal titration calorimetry data showed favorable binding profile for 6aagainst both wild type and MDR769 HIV-1 protease variants. Nuclear magnetic resonance spectrum of {sup 15}N-labeled MDR769 HIV-1 protease in complex with 6a showed some major perturbations in chemical shift, supporting the peptide induced conformational changes in protease. Modeling analysis revealed multiple contacts between 6a and MDR769 HIV-1 protease. The lead peptide-inhibitor, 6a, with high potency and good binding profile can be used as the basis for developing potent small molecule inhibitors against MDR variants of HIV.« less

New peptide deformylase inhibitors design, synthesis and pharmacokinetic assessment.

PubMed

Lv, Fengping; Chen, Chen; Tang, Yang; Wei, Jianhai; Zhu, Tong; Hu, Wenhao

2016-08-01

The docking approach for the screening of designed small molecule ligands, led to the identification of a critical arginine residue in peptide deformylase for spiro cyclopropyl PDF inhibitor's extra hydrophobic binding, providing us a useful tool for searching more efficient PDF inhibitors to fight for horrifying antibiotics resistance. Further synthetic modification was undertaken to optimize the potency of amide compounds. To lower metabolic susceptibility and in turn reduce unwanted metabolic toxicity that was observed clinically, while retaining desired antibacterial activity, the use of azoles as amide bioisosteres had also been investigated. After the completion of chemical synthesis, all the compounds were evaluated through in vitro antibacterial activity assay, some of which were further subject to in vivo rat pharmacokinetic assessment. Those findings in this letter showed that spiro cyclopropyl proline N-formyl hydroxylamines, and especially the bioisosteric azoles, can represent a promising class of PDF inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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

2017-09-20

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

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

PubMed

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

2016-01-01

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

Effect of dipeptidyl peptidase-4 inhibitors on circulating tumor necrosis factor-α concentrations: A systematic review and meta-analysis of controlled trials.

PubMed

Atkin, Stephen L; Katsiki, Niki; Banach, Maciej; Mikhailidis, Dimitri P; Pirro, Matteo; Sahebkar, Amirhossein

2017-09-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors improve glycemic control in patients with type 2 diabetes mellitus. There are also reports of an effect of these drugs in reducing inflammation through inhibition of tumor necrosis factor-α (TNF-α) that is an important mediator for several inflammatory processes. The present systematic review and meta-analysis were performed to evaluate the effect of DPP-4 inhibitors on circulating TNF-α levels in T2DM patients. A systematic review and a meta-analysis were undertaken on all controlled trials of DPP-4 inhibitors that included measurement of TNF-α. The search included PubMed-Medline, Scopus, ISI Web of Knowledge and Google Scholar databases. Quantitative data synthesis was performed using a random-effects model, with standardized mean difference (SMD) and 95% confidence interval (CI) as summary statistics. Meta-regression and leave-one-out sensitivity analysis were performed to assess the modifiers of treatment response. Eight eligible articles (6 with sitagliptin and 2 with vildagliptin) comprising 9 treatment arms were selected for this meta-analysis. Meta-analysis suggested a significant reduction of circulating TNF-α concentrations following treatment with DPP-4 inhibitors (SMD: -1.84, 95% CI: -2.88, -0.80, p=0.001). The effect size was robust in the sensitivity analysis and not mainly driven by a single study. A subgroup analysis did not suggest any significant difference between the TNF-α-lowering activity of sitagliptin (SMD: -1.49, 95% CI: -2.89, -0.10) and vildagliptin (SMD: -2.80, 95% CI: -4.98, -0.61) (p=0.326). This meta-analysis of the 8 available controlled trials showed that DPP-4 inhibition in patients with type 2 diabetes mellitus was associated with significant reductions in plasma TNF-α levels with no apparent difference between sitagliptin and vildagliptin. Copyright © 2017 Elsevier Inc. All rights reserved.

Dimethylaminoethanol (deanol) metabolism in rat brain and its effect on acetylcholine synthesis.

PubMed

Jope, R S; Jenden, D J

1979-12-01

Specific methods utilizing combined gas chromatography mass spectrometry were used to measure the metabolism of [2H6] deanol and its effects on acetylcholine concentration in vitro and in vivo. In vitro [2H6]deanol was rapidly taken up by rat brain synaptosomes, but was neither methylated nor acetylated. [2H6]Deanol was a weak competitive inhibitor of the high affinity transport of [2H4]choline, thus reducing the synthesis of [2H4]acetylcholine. In vivo [2H6]deanol was present in the brain after i.p. or p.o. administration, but was not methylated or acetylated. Treatment of rats with [2H6]deanol significantly increased the concentration of choline in the plasma and brain but did not alter the concentration of acetylcholine in the brain. Treatment of rats with atropine (to stimulate acetylcholine turnover) or with hemicholinium-3 (to inhibit the high affinity transport of choline) did not reveal any effect of [2H6]deanol on acetylcholine synthesis in vivo. However, since [2H6]deanol did increase brain choline, it may prove therapeutically useful when the production of choline is reduced or when the utilization of choline for the synthesis of acetylcholine is impaired.

Differential response of orthologous L,L-diaminopimelate aminotransferases (DapL) to enzyme inhibitory antibiotic lead compounds.

PubMed

McKinnie, Shaun M K; Rodriguez-Lopez, Eva M; Vederas, John C; Crowther, Jennifer M; Suzuki, Hironori; Dobson, Renwick C J; Leustek, Thomas; Triassi, Alexander J; Wheatley, Matthew S; Hudson, André O

2014-01-01

L,L-Diaminopimelate aminotransferase (DapL) is an enzyme required for the biosynthesis of meso-diaminopimelate (m-DAP) and L-lysine (Lys) in some bacteria and photosynthetic organisms. m-DAP and Lys are both involved in the synthesis of peptidoglycan (PG) and protein synthesis. DapL is found in specific eubacterial and archaeal lineages, in particular in several groups of pathogenic bacteria such as Leptospira interrogans (LiDapL), the soil/water bacterium Verrucomicrobium spinosum (VsDapL) and the alga Chlamydomonas reinhardtii (CrDapL). Here we present the first comprehensive inhibition study comparing the kinetic activity of DapL orthologs using previously active small molecule inhibitors formerly identified in a screen with the DapL of Arabidopsis thaliana (AtDapL), a flowering plant. Each inhibitor is derived from one of four classes with different central structural moieties: a hydrazide, a rhodanine, a barbiturate, or a thiobarbituate functionality. The results show that all five compounds tested were effective at inhibiting the DapL orthologs. LiDapL and AtDapL showed similar patterns of inhibition across the inhibitor series, whereas the VsDapL and CrDapL inhibition patterns were different from that of LiDapL and AtDapL. CrDapL was found to be insensitive to the hydrazide (IC₅₀ >200 μM). VsDapL was found to be the most sensitive to the barbiturate and thiobarbiturate containing inhibitors (IC₅₀ ∼5 μM). Taken together, the data shows that the homologs have differing sensitivities to the inhibitors with IC₅₀ values ranging from 4.7 to 250 μM. In an attempt to understand the basis for these differences the four enzymes were modeled based on the known structure of AtDapL. Overall, it was found that the enzyme active sites were conserved, although the second shell of residues close to the active site were not. We conclude from this that the altered binding patterns seen in the inhibition studies may be a consequence of the inhibitors forming additional interactions with residues proximal to the active site, or that the inhibitors may not act by binding to the active site. Compounds that are specific for DapL could be potential biocides (antibiotic, herbicide or algaecide) that are nontoxic to animals since animals do not contain the enzymes necessary for PG or Lys synthesis. This study provides important information to expand our current understanding of the structure/activity relationship of DapL and putative inhibitors that are potentially useful for the design and or discovery of novel biocides. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Leucine stimulates protein synthesis in skeletal muscle of neonatal pigs by enhancing mTORC1 activation.

PubMed

Suryawan, Agus; Jeyapalan, Asumthia S; Orellana, Renan A; Wilson, Fiona A; Nguyen, Hanh V; Davis, Teresa A

2008-10-01

Skeletal muscle in the neonate grows at a rapid rate due in part to an enhanced sensitivity to the postprandial rise in amino acids, particularly leucine. To elucidate the molecular mechanism by which leucine stimulates protein synthesis in neonatal muscle, overnight-fasted 7-day-old piglets were treated with rapamycin [an inhibitor of mammalian target of rapamycin (mTOR) complex (mTORC)1] for 1 h and then infused with leucine for 1 h. Fractional rates of protein synthesis and activation of signaling components that lead to mRNA translation were determined in skeletal muscle. Rapamycin completely blocked leucine-induced muscle protein synthesis. Rapamycin markedly reduced raptor-mTOR association, an indicator of mTORC1 activation. Rapamycin blocked the leucine-induced phosphorylation of mTOR, S6 kinase 1 (S6K1), and eukaryotic initiation factor (eIF)4E-binding protein-1 (4E-BP1) and formation of the eIF4E.eIF4G complex and increased eIF4E.4E-BP1 complex abundance. Rapamycin had no effect on the association of mTOR with rictor, a crucial component for mTORC2 activation, or G protein beta-subunit-like protein (GbetaL), a component of mTORC1 and mTORC2. Neither leucine nor rapamycin affected the phosphorylation of AMP-activated protein kinase (AMPK), PKB, or tuberous sclerosis complex (TSC)2, signaling components that reside upstream of mTOR. Eukaryotic elongation factor (eEF)2 phosphorylation was not affected by leucine or rapamycin, although current dogma indicates that eEF2 phosphorylation is mTOR dependent. Together, these in vivo data suggest that leucine stimulates muscle protein synthesis in neonates by enhancing mTORC1 activation and its downstream effectors.

Leucine stimulates protein synthesis in skeletal muscle of neonatal pigs by enhancing mTORC1 activation

PubMed Central

Suryawan, Agus; Jeyapalan, Asumthia S.; Orellana, Renan A.; Wilson, Fiona A.; Nguyen, Hanh V.; Davis, Teresa A.

2008-01-01

Skeletal muscle in the neonate grows at a rapid rate due in part to an enhanced sensitivity to the postprandial rise in amino acids, particularly leucine. To elucidate the molecular mechanism by which leucine stimulates protein synthesis in neonatal muscle, overnight-fasted 7-day-old piglets were treated with rapamycin [an inhibitor of mammalian target of rapamycin (mTOR) complex (mTORC)1] for 1 h and then infused with leucine for 1 h. Fractional rates of protein synthesis and activation of signaling components that lead to mRNA translation were determined in skeletal muscle. Rapamycin completely blocked leucine-induced muscle protein synthesis. Rapamycin markedly reduced raptor-mTOR association, an indicator of mTORC1 activation. Rapamycin blocked the leucine-induced phosphorylation of mTOR, S6 kinase 1 (S6K1), and eukaryotic initiation factor (eIF)4E-binding protein-1 (4E-BP1) and formation of the eIF4E·eIF4G complex and increased eIF4E·4E-BP1 complex abundance. Rapamycin had no effect on the association of mTOR with rictor, a crucial component for mTORC2 activation, or G protein β-subunit-like protein (GβL), a component of mTORC1 and mTORC2. Neither leucine nor rapamycin affected the phosphorylation of AMP-activated protein kinase (AMPK), PKB, or tuberous sclerosis complex (TSC)2, signaling components that reside upstream of mTOR. Eukaryotic elongation factor (eEF)2 phosphorylation was not affected by leucine or rapamycin, although current dogma indicates that eEF2 phosphorylation is mTOR dependent. Together, these in vivo data suggest that leucine stimulates muscle protein synthesis in neonates by enhancing mTORC1 activation and its downstream effectors. PMID:18682538

Synthesis, characterization and cytotoxicity studies of 1,2,3-triazoles and 1,2,4-triazolo [1,5-a] pyrimidines in human breast cancer cells.

PubMed

Gilandoust, Maryam; Harsha, Kachigere B; Mohan, Chakrabhavi Dhananjaya; Raquib, Ainiah Rushdiana; Rangappa, Shobith; Pandey, Vijay; Lobie, Peter E; Basappa; Rangappa, Kanchugarakoppal S

2018-05-09

Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) is essential for physiological functions of tissues and neovasculature. VEGFR signaling is associated with the progression of pathological angiogenesis in various types of malignancies, making it an attractive therapeutic target in cancer treatment. In the present work, we report the synthesis of 1,4-disubstituted 1,2,3-triazoles and 1,2,4-triazolo[1, 5-a]pyrimidine derivatives via copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction and screened for their anticancer activity against MCF7 cells. We identified 1-(2'-ethoxy-4'-fluoro-[1,1'-biphenyl]-4-yl)-4-phenyl-1H-1,2,3-triazole (EFT) as lead cytotoxic agent against MCF7 cell lines with an IC 50 value of 1.69 µM. Further evaluation revealed that EFT induces cytotoxicity on Ishikawa, MDA-MB-231 and BT474 cells with IC 50 values of 1.97, 4.81 and 4.08 µM respectively. However, EFT did not induce cytotoxicity in normal lung epithelial (BEAS-2B) cells. Previous reports suggested that 1,2,3-triazoles are the inhibitors of VEGFR1 and therefore, we evaluated the effect of EFT on the expression of VEGFR1. The results demonstrated that EFT downregulates the expression of VEGFR1 in MCF7 cells. In summary, we identified a potent cytotoxic agent that imparts its antiproliferative activity by targeting VEGFR1 in breast cancer cells. The novel compound could serve as a lead structure in developing VEGFR1 inhibitors. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthesis and Initial in Vivo Studies with [11C]SB-216763: The First Radiolabeled Brain Penetrative Inhibitor of GSK-3

PubMed Central

2015-01-01

Quantifying glycogen synthase kinase-3 (GSK-3) activity in vivo using positron emission tomography (PET) imaging is of interest because dysregulation of GSK-3 is implicated in numerous diseases and neurological disorders for which GSK-3 inhibitors are being considered as therapeutic strategies. Previous PET radiotracers for GSK-3 have been reported, but none of the published examples cross the blood–brain barrier. Therefore, we have an ongoing interest in developing a brain penetrating radiotracer for GSK-3. To this end, we were interested in synthesis and preclinical evaluation of [11C]SB-216763, a high-affinity inhibitor of GSK-3 (Ki = 9 nM; IC50 = 34 nM). Initial radiosyntheses of [11C]SB-216763 proved ineffective in our hands because of competing [3 + 3] sigmatropic shifts. Therefore, we have developed a novel one-pot two-step synthesis of [11C]SB-216763 from a 2,4-dimethoxybenzyl-protected maleimide precursor, which provided high specific activity [11C]SB-216763 in 1% noncorrected radiochemical yield (based upon [11C]CH3I) and 97–100% radiochemical purity (n = 7). Initial preclinical evaluation in rodent and nonhuman primate PET imaging studies revealed high initial brain uptake (peak rodent SUV = 2.5 @ 3 min postinjection; peak nonhuman primate SUV = 1.9 @ 5 min postinjection) followed by washout. Brain uptake was highest in thalamus, striatum, cortex, and cerebellum, areas known to be rich in GSK-3. These results make the arylindolemaleimide skeleton our lead scaffold for developing a PET radiotracer for quantification of GSK-3 density in vivo and ultimately translating it into clinical use. PMID:26005531

Novel guanidine-based inhibitors of inosine monophosphate dehydrogenase.

PubMed

Iwanowicz, Edwin J; Watterson, Scott H; Liu, Chunjian; Gu, Henry H; Mitt, Toomas; Leftheris, Katerina; Barrish, Joel C; Fleener, Catherine A; Rouleau, Katherine; Sherbina, N Z; Hollenbaugh, Diane L

2002-10-21

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

Cell wall biogenesis in Oocystis: experimental alteration of microfibril assembly and orientation.

PubMed

Montezinos, D; Brown, R M

1978-01-01

Cell wall biogenesis in the unicellular green alga Oocystis apiculata has been studied. Under normal growth conditions, a cell wall with ordered microfibrils is synthesized. In each layer there are rows of parallel microfibrils. Layers are nearly perpendicular to each other. Terminal linear synthesizing complexes are located in the plasma membrane, and they are capable of bidirectional synthesis of cellulose microfibrils. Granule bands associated with the inner leaflet of the plasma membrane appear to control the orientation of newly synthesized microfibrils. Subcortical microtubules also are present during wall synthesis. Patterns of cell wall synthesis were studied after treatment with EDTA and EGTA as well as divalent cations (MgSO4, CaSO4, Cacl2). 0.1 M EDTA treatment for 15 min results in the disassociation of the terminal complexes from the ends of microfibrils. EDTA-treated cells followed by 15 min treatment with MgSO4 results in reaggregation of the linear complexes into a paired state, remote from the original ends to which they were associated. After 90 min treatment with MgSO4, normal synthesis resumes. EGTA and calcium salts do not affect the linear complexes or microfibril orientation. Treatments with colchicine and vinblastine sulphate do not depolymerize the microtubles, but the wall microfibril orientation is altered. With colchicine or vinblastine, the change in orientation from layer to layer is inhibited. The process is reversible upon removal of the drugs. Lumicolchicine has no effect upon microfibril orientation, but granule bands are disorganized. Treatment with coumarin, a known inhibitor of cellulose synthesis, causes the loss of visualization of subunits of the terminal complexes. The possibility of the existence of a membrane-associated colchicine-sensitive orientation protein for cellulose microfibrils is discussed. Transmembrane modulation of microfibril synthesis and orientation is presented.

Role of neurosteroids in the anticonvulsant activity of midazolam.

PubMed

Dhir, Ashish; Rogawski, Michael A

2012-04-01

Midazolam is a short-acting benzodiazepine that is widely used as an i.v. sedative and anticonvulsant. Besides interacting with the benzodiazepine site associated with GABA(A) receptors, some benzodiazepines act as agonists of translocator protein (18 kDa) (TSPO) to enhance the synthesis of steroids, including neurosteroids with positive modulatory actions on GABA(A) receptors. We sought to determine if neurosteroidogenesis induced by midazolam contributes to its anticonvulsant action. Mice were pretreated with neurosteroid synthesis inhibitors and potentiators followed by midazolam or clonazepam, a weak TSPO ligand. Anticonvulsant activity was assessed with the i.v. pentylenetetrazol (PTZ) threshold test. Midazolam (500-5000 µg·kg(-1) , i.p.) caused a dose-dependent increase in seizure threshold. Pretreatment with the neurosteroid synthesis inhibitors finasteride, a 5α-reductase inhibitor, and a functional TSPO antagonist PK 11195, reduced the anticonvulsant action of midazolam. The anticonvulsant action of midazolam was enhanced by the neurosteroidogenic drug metyrapone, an 11β-hydroxylase inhibitor. In contrast, the anticonvulsant action of clonazepam (100 µg·kg(-1) ) was reduced by finasteride but not by PK 11195, indicating a possible contribution of neurosteroids unrelated to TSPO. Enhanced endogenous neurosteroid synthesis, possibly mediated by an interaction with TSPO, contributed to the anticonvulsant action of midazolam. Enhanced neurosteroidogenesis may also be a factor in the actions of other benzodiazepines, even those that only weakly interact with TSPO. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Role of neurosteroids in the anticonvulsant activity of midazolam

PubMed Central

Dhir, Ashish; Rogawski, Michael A

2012-01-01

BACKGROUND AND PURPOSE Midazolam is a short-acting benzodiazepine that is widely used as an i.v. sedative and anticonvulsant. Besides interacting with the benzodiazepine site associated with GABAA receptors, some benzodiazepines act as agonists of translocator protein (18 kDa) (TSPO) to enhance the synthesis of steroids, including neurosteroids with positive modulatory actions on GABAA receptors. We sought to determine if neurosteroidogenesis induced by midazolam contributes to its anticonvulsant action. EXPERIMENTAL APPROACH Mice were pretreated with neurosteroid synthesis inhibitors and potentiators followed by midazolam or clonazepam, a weak TSPO ligand. Anticonvulsant activity was assessed with the i.v. pentylenetetrazol (PTZ) threshold test. KEY RESULTS Midazolam (500–5000 µg·kg−1, i.p.) caused a dose-dependent increase in seizure threshold. Pretreatment with the neurosteroid synthesis inhibitors finasteride, a 5α-reductase inhibitor, and a functional TSPO antagonist PK 11195, reduced the anticonvulsant action of midazolam. The anticonvulsant action of midazolam was enhanced by the neurosteroidogenic drug metyrapone, an 11β-hydroxylase inhibitor. In contrast, the anticonvulsant action of clonazepam (100 µg·kg−1) was reduced by finasteride but not by PK 11195, indicating a possible contribution of neurosteroids unrelated to TSPO. CONCLUSION AND IMPLICATIONS Enhanced endogenous neurosteroid synthesis, possibly mediated by an interaction with TSPO, contributed to the anticonvulsant action of midazolam. Enhanced neurosteroidogenesis may also be a factor in the actions of other benzodiazepines, even those that only weakly interact with TSPO. PMID:22014182

Resveratrol induces growth inhibition and apoptosis in metastatic breast cancer cells via de novo ceramide signaling.

PubMed

Scarlatti, Francesca; Sala, Giusy; Somenzi, Giulia; Signorelli, Paola; Sacchi, Nicoletta; Ghidoni, Riccardo

2003-12-01

Resveratrol (3,4',5-trans-trihydroxystilbene), a phytoalexin present in grapes and red wine, is emerging as a natural compound with potential anticancer properties. Here we show that resveratrol can induce growth inhibition and apoptosis in MDA-MB-231, a highly invasive and metastatic breast cancer cell line, in concomitance with a dramatic endogenous increase of growth inhibitory/proapoptotic ceramide. We found that accumulation of ceramide derives from both de novo ceramide synthesis and sphingomyelin hydrolysis. More specifically we demonstrated that ceramide accumulation induced by resveratrol can be traced to the activation of serine palmitoyltransferase (SPT), the key enzyme of de novo ceramide biosynthetic pathway, and neutral sphingomyelinase (nSMase), a main enzyme involved in the sphingomyelin/ceramide pathway. However, by using specific inhibitors of SPT, myriocin and L-cycloserine, and nSMase, gluthatione and manumycin, we found that only the SPT inhibitors could counteract the biological effects induced by resveratrol. Thus, resveratrol seems to exert its growth inhibitory/apoptotic effect on the metastatic breast cancer cell line MDA-MB-231 by activating the de novo ceramide synthesis pathway.

Social Recognition Memory Requires Two Stages of Protein Synthesis in Mice

ERIC Educational Resources Information Center

Wolf, Gerald; Engelmann, Mario; Richter, Karin

2005-01-01

Olfactory recognition memory was tested in adult male mice using a social discrimination task. The testing was conducted to begin to characterize the role of protein synthesis and the specific brain regions associated with activity in this task. Long-term olfactory recognition memory was blocked when the protein synthesis inhibitor anisomycin was…

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

ERIC Educational Resources Information Center

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

2010-01-01

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

Acridone-based inhibitors of inosine 5'-monophosphate dehydrogenase: discovery and SAR leading to the identification of N-(2-(6-(4-ethylpiperazin-1-yl)pyridin-3-yl)propan-2-yl)-2- fluoro-9-oxo-9,10-dihydroacridine-3-carboxamide (BMS-566419).

PubMed

Watterson, Scott H; Chen, Ping; Zhao, Yufen; Gu, Henry H; Dhar, T G Murali; Xiao, Zili; Ballentine, Shelley K; Shen, Zhongqi; Fleener, Catherine A; Rouleau, Katherine A; Obermeier, Mary; Yang, Zheng; McIntyre, Kim W; Shuster, David J; Witmer, Mark; Dambach, Donna; Chao, Sam; Mathur, Arvind; Chen, Bang-Chi; Barrish, Joel C; Robl, Jeffrey A; Townsend, Robert; Iwanowicz, Edwin J

2007-07-26

Inosine monophosphate dehydrogenase (IMPDH), a key enzyme in the de novo synthesis of guanosine nucleotides, catalyzes the irreversible nicotinamide-adenine dinucleotide dependent oxidation of inosine-5'-monophosphate to xanthosine-5'-monophosphate. Mycophenolate Mofetil (MMF), a prodrug of mycophenolic acid, has clinical utility for the treatment of transplant rejection based on its inhibition of IMPDH. The overall clinical benefit of MMF is limited by what is generally believed to be compound-based, dose-limiting gastrointestinal (GI) toxicity that is related to its specific pharmacokinetic characteristics. Thus, development of an IMPDH inhibitor with a novel structure and a different pharmacokinetic profile may reduce the likelihood of GI toxicity and allow for increased efficacy. This article will detail the discovery and SAR leading to a novel and potent acridone-based IMPDH inhibitor 4m and its efficacy and GI tolerability when administered orally in a rat adjuvant arthritis model.

Synthesis, Biological Activity, and Crystal Structure of Potent Nonnucleoside Inhibitors of HIV-1 Reverse Transcriptase That Retain Activity against Mutant Forms of the Enzyme†

PubMed Central

Morningstar, Marshall L.; Roth, Thomas; Farnsworth, David W.; Smith, Marilyn Kroeger; Watson, Karen; Buckheit, Robert W.; Das, Kalyan; Zhang, Wanyi; Arnold, Eddy; Julias, John G.; Hughes, Stephen H.; Michejda, Christopher J.

2010-01-01

In an ongoing effort to develop novel and potent nonnucleoside HIV-1 reverse transcriptase (RT) inhibitors that are effective against the wild type (WT) virus and clinically observed mutants, 1,2-bis-substituted benzimidazoles were synthesized and tested. Optimization of the N1 and C2 positions of benzimidazole led to the development of 1-(2,6-difluorobenzyl)-2-(2,6-difluorophenyl)-4-methylbenzimidazole (1) (IC50 = 0.2 μM, EC50 = 0.44 μM, and TC50 ≥ 100 against WT). This paper describes how substitution on the benzimidazole ring profoundly affects activity. Substituents at the benzimidazole C4 dramatically enhanced potency, while at C5 or C6 substituents were generally detrimental or neutral to activity, respectively. A 7-methyl analogue did not inhibit HIV-1 RT. Determination of the crystal structure of 1 bound to RT provided the basis for accurate modeling of additional analogues, which were synthesized and tested. Several derivatives were nanomolar inhibitors of wild-type virus and were effective against clinically relevant HIV-1 mutants. PMID:17663538

Synthesis and biological activities of novel 5-substituted-1,3,4-oxadiazole Mannich bases and bis-Mannich bases as ketol-acid reductoisomerase inhibitors.

PubMed

Zhang, Yan; Liu, Xing-Hai; Zhan, Yi-Zhou; Zhang, Li-Yuan; Li, Zheng-Ming; Li, Yong-Hong; Zhang, Xiao; Wang, Bao-Lei

2016-10-01

A series of novel 5-substituted-1,3,4-oxadiazole Mannich bases and bis-Mannich bases have been conveniently synthesized in good yields. Their structures were characterized by IR, (1)H NMR, (13)C NMR and elemental analysis. The preliminary bioassay results indicated that some of the compounds showed promising in vitro fungicidal activities towards several test plant fungi; some of them exhibited significant herbicidal activities against Brassica campestris and excellent in vitro inhibitory activities against rice ketol-acid reductoisomerase (KARI). Among 14 novel compounds, 8c, 8d and 8m showed potent KARI inhibitory activities with Ki value of (0.96±0.42), (3.86±0.49) and (3.10±0.71) μmol/L, respectively, and were comparable with IpOHA. These compounds could be novel KARI inhibitors for further investigation. The density functional theory (DFT) calculations and molecular docking were carried out to study the structure-activity relationship (SAR) of the active inhibitors in this Letter. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acute inhibition of neurosteroid estrogen synthesis suppresses status epilepticus in an animal model

PubMed Central

Sato, Satoru M; Woolley, Catherine S

2016-01-01

Status epilepticus (SE) is a common neurological emergency for which new treatments are needed. In vitro studies suggest a novel approach to controlling seizures in SE: acute inhibition of estrogen synthesis in the brain. Here, we show in rats that systemic administration of an aromatase (estrogen synthase) inhibitor after seizure onset strongly suppresses both electrographic and behavioral seizures induced by kainic acid (KA). We found that KA-induced SE stimulates synthesis of estradiol (E2) in the hippocampus, a brain region commonly involved in seizures and where E2 is known to acutely promote neural activity. Hippocampal E2 levels were higher in rats experiencing more severe seizures. Consistent with a seizure-promoting effect of hippocampal estrogen synthesis, intra-hippocampal aromatase inhibition also suppressed seizures. These results reveal neurosteroid estrogen synthesis as a previously unknown factor in the escalation of seizures and suggest that acute administration of aromatase inhibitors may be an effective treatment for SE. DOI: http://dx.doi.org/10.7554/eLife.12917.001 PMID:27083045

Effects of (-)-S-2,8-dimethyl-3-methylene-1-oxa-8-azaspiro[4,5]decane L-tartrate monohydrate (YM796), a novel muscarinic agonist, on disturbance of passive avoidance learning behavior in drug-treated and senescence-accelerated mice.

PubMed

Suzuki, M; Yamaguchi, T; Ozawa, Y; Ohyama, M; Yamamoto, M

1995-11-01

Effects of YM796 (-)-S-2,8-dimethyl-3-methylene-1-oxa-8-azaspiro[4,5]decane L-tartrate monohydrate; a novel muscarinic agonist, were observed on disturbance of passive avoidance learning behavior in drug- (protein synthesis inhibitor and anticholinergic drugs) treated and senescence-accelerated mice in comparison with those of a muscarinic agonist (AF102B) and acetylcholinesterase inhibitors (E2020 (1-benzyl-4-[(5,6-dimethoxy-1-indanone-2-yl) methyl] piperidene hydrochloride), NIK247 [9-amino-2,3,5,6,7,8-hexahydro-1H-cyclopenta(b)-quinoline monohydrate hydrochloride], THA (9-amino-1,2,3,4-tetrahydroacridine) and physostigmine). All tested drugs administered before training significantly prolonged the shortened latency of step-through induced by the protein synthesis inhibitor cycloheximide (150 mg/kg s.c.). This shortened latency was also significantly prolonged when YM796 was administered immediately after training, but not when administered before the test trial. The ameliorating effect of YM796 on the impairment in learning behavior by cycloheximide was significantly suppressed by pirenzepine (0.1 micrograms/mouse i.c.v.). When administered before training, all test drugs prolonged the shortened latency of step-through induced by treatment with the anticholinergic drugs [scopolamine (1 mg/kg s.c.) and hemicholinium-3 (0.3 microgram/mouse i.c.v.)], suggesting that they ameliorated the impairment of learning behavior. This shortened latency in scopolamine-treated mice was also significantly prolonged by YM796, AF102B, E2020, NIK247 and physostigmine when administered immediately after training, but not when administered before the test trial. The pharmacological actions of YM796 administered immediately after training and before the test trial in hemicholinium-3-treated mice were similar to those in scopolamine-treated mice.(ABSTRACT TRUNCATED AT 250 WORDS)

New Human Monoamine Oxidase A Inhibitors with Potential Anti- Depressant Activity: Design, Synthesis, Biological Screening and Evaluation of Pharmacological Activity.

PubMed

Evranos-Aksoz, Begum; Ucar, Gulberk; Tas, Sadik Taskin; Aksoz, Erkan; Yelekci, Kemal; Erikci, Acelya; Sara, Yildirim; Iskit, Alper Bektas

2017-01-01

Depression is a momentous disease that can greatly reduce the quality of life and cause death. In depression, neurotransmitter levels such as serotonine, dopamine and noradrenaline are impaired. Monoamine oxidases (MAO) are responsible for oxidative catalysis of these monoamine neurotransmitters. Because of this relation, MAO-A inhibitors show antidepressant activity by regulating neurotransmitter levels. This study was carried out to investigate the design, synthesis and activity of new antidepressant compounds in pyrazoline and hydrazone structure. Chalcones and hydrazides were heated under reflux to give new pyrazoline and hydrazone derivatives. Docking simulations were performed using AutoDock4.2. hMAO activities were determined by a fluorimetric method. To determine cell viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used. Behavioral activities of the three compounds were determined by using Forced Swim Test, Step-Through Passive Avoidance Test, Elevated Plus Maze and Open Field Arena Tests. According to in vitro tests, all of the synthesized compounds were found more potent than moclobemide and six of the synthesized compounds were found more selective than moclobemide. Three of the synthesized compounds were investigated for their behavioral activities comparing with moclobemide after 7 days of i.p. treatment at 30 mg/kg. One of the three compounds elicited significant antidepressant properties. All of the synthesized compounds were found potent hMAO-A inhibitors in in vitro screening tests. Only one of the in vivo tested three compounds, (3-(2-hydroxy-5-methylphenyl)-5- p-tolyl-4,5-dihydropyrazol-1-yl)(pyridin-4-yl) methanone indicated significant antidepressant activity. This article opens a window for further development of new pyrazoline and hydrazone derivatives as antidepressant agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Synthesis and biological evaluation of a gamma-cyclodextrin-based formulation of the anticancer agent 5,6,11,12,17,18,23,24-octahydrocyclododeca[1,2-b:4,5-b':7,8-b'':10,11-b''']tetraindole (CTet).

PubMed

Lucarini, Simone; De Santi, Mauro; Antonietti, Francesca; Brandi, Giorgio; Diamantini, Giuseppe; Fraternale, Alessandra; Paoletti, Maria Filomena; Tontini, Andrea; Magnani, Mauro; Duranti, Andrea

2010-06-04

5,6,11,12,17,18,23,24-Octahydrocyclododeca[1,2-b:4,5-b':7,8-b'':10,11- b''']tetrai ndole (CTet), an indole-3-carbinol (I3C) metabolite endowed with anticancer properties, is poorly soluble in the solvents most frequently used in biological tests. This study indicates that the use of gamma-cyclodextrin (gamma-CD) avoids this problem. Formulated with gamma-CD CTet is a potent inhibitor of DNA synthesis in both estrogen receptor positive (MCF-7) and estrogen receptor negative (MDA-MB-231) human breast cell lines (IC50 = 1.20 +/- 0.04 microM and 1.0 +/- 0.1 microM, respectively).

Amino Compounds as Inhibitors of De Novo Synthesis of Chlorobenzenes

NASA Astrophysics Data System (ADS)

Wang, Si-Jia; He, Pin-Jing; Lu, Wen-Tao; Shao, Li-Ming; Zhang, Hua

2016-04-01

The inhibitory effects of four amino compounds on the formation of chlorobenzenes (CBzs) - dioxin precursors and indicators, and the inhibitory mechanisms were explored. The results show NH4H2PO4 can decrease the total yields of CBzs (1,2di-CBz, 1,3di-CBz, 1,4di-CBz, penta-CBz and hexa-CBz) by 98.1%±1.6% and 96.1%±0.7% under air and nitrogen flow. The inhibitory effects indicated by the total yields of CBzs follow the order NH4H2PO4 > NH4HF2 > (NH4)2SO4 > NH4Br under air flow and NH4H2PO4 ≈ (NH4)2SO4 ≈ NH4HF2 >NH4Br under nitrogen flow. The inhibition mechanism revealed by thermal analysis that CuCl2 was converted to CuPO3 by reacting with NH4H2PO4 below 200 °C, which can block the transfer of chlorine and formation of C-Cl bonds at 350 °C. The effects of the other three inhibitors were weaker because their reactions with CuCl2, which form other copper compounds, and the reaction of CuCl2 with carbon, which forms C-Cl bonds, were almost simultaneous and competitive. Oxygen influenced the yield of CBzs obviously, and the total yield of five CBzs sharply increased with oxygen. Because of their high efficiency, low environmental impact, low cost, and availability, amino compounds - especially NH4H2PO4 - can be utilized as inhibitors of CBzs during incineration.

Multipotent drugs with cholinergic and neuroprotective properties for the treatment of Alzheimer and neuronal vascular diseases. I. Synthesis, biological assessment, and molecular modeling of simple and readily available 2-aminopyridine-, and 2-chloropyridine-3,5-dicarbonitriles.

PubMed

Samadi, Abdelouahid; Marco-Contelles, José; Soriano, Elena; Alvarez-Pérez, Mónica; Chioua, Mourad; Romero, Alejandro; González-Lafuente, Laura; Gandía, Luis; Roda, José M; López, Manuela G; Villarroya, Mercedes; García, Antonio G; Ríos, Cristóbal de Los

2010-08-15

The synthesis, molecular modeling, and pharmacological analysis of new multipotent simple, and readily available 2-aminopyridine-3,5-dicarbonitriles (3-20), and 2-chloropyridine-3,5-dicarbonitriles (21-28), prepared from 2-amino-6-chloropyridine-3,5-dicarbonitrile (1) and 2-amino-6-chloro-4-phenylpyridine-3,5-dicarbonitrile (2) is described. The biological evaluation showed that some of these molecules were modest inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), in the micromolar range. The 2-amino (3, 4), and 2-chloro derivatives 21-23, 25, 26 were AChE selective inhibitors, whereas 2-amino derivatives 5, 14 proved to be selective for BuChE. Only inhibitor 24 was equipotent for both cholinesterases. Kinetic studies on compound 23 showed that this compound is a mixed-type inhibitor of AChE showing a K(i) of 6.33 microM. No clear SAR can be obtained form these data, but apparently, compounds bearing small groups such as the N,N'-dimethylamino or the pyrrolidino, regardless of the presence of a 2-amino, or 6-chloro substituent in the pyridine ring, preferentially inhibit AChE. Molecular modeling on inhibitors 4, 5, 22, and 23 has been carried out to give a better insight into the binding mode on the catalytic active site (CAS), and peripheral anionic site (PAS) of AChE. The most important differences in the observed binding relay on the modifications of the group at C2, as the amino group forms two hydrogen bonds that direct the binding mode, while in the case of compounds with a chlorine atom, this is not possible. The neuroprotective profile of these molecules has been investigated. In the LDH test, only compounds 26, 3, 22, and 24 showed neuroprotection with values in the range 37.8-31.6% in SH-SY5Y neuroblastoma cells stressed with a mixture of oligomycin-A/rotenone, but in the MTT test only compound 17 (32.9%) showed a similar profile. Consequently, these compounds can be considered as attractive multipotent therapeutic molecules on two key pharmacological receptors playing key roles in the progress of Alzheimer, that is, cholinergic dysfunction and oxidative stress, and neuronal vascular diseases. Copyright 2010 Elsevier Ltd. All rights reserved.

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

PubMed

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

2017-08-01

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

The application of click chemistry in the synthesis of agents with anticancer activity

PubMed Central

Ma, Nan; Wang, Ying; Zhao, Bing-Xin; Ye, Wen-Cai; Jiang, Sheng

2015-01-01

The copper(I)-catalyzed 1,3-dipolar cycloaddition between alkynes and azides (click chemistry) to form 1,2,3-triazoles is the most popular reaction due to its reliability, specificity, and biocompatibility. This reaction has the potential to shorten procedures, and render more efficient lead identification and optimization procedures in medicinal chemistry, which is a powerful modular synthetic approach toward the assembly of new molecular entities and has been applied in anticancer drugs discovery increasingly. The present review focuses mainly on the applications of this reaction in the field of synthesis of agents with anticancer activity, which are divided into four groups: topoisomerase II inhibitors, histone deacetylase inhibitors, protein tyrosine kinase inhibitors, and antimicrotubule agents. PMID:25792812

Attenuation of biopterin synthesis prevents Escherichia coli K1 invasion of brain endothelial cells and the development of meningitis in newborn mice.

PubMed

Shanmuganathan, Muthusamy V; Krishnan, Subramanian; Fu, Xiaowei; Prasadarao, Nemani V

2013-01-01

Elevated levels of pterins and nitric oxide (NO) are observed in patients with septic shock and bacterial meningitis. We demonstrate that Escherichia coli K1 infection of human brain microvascular endothelial cells (HBMECs) induces the expression of guanosine triphosphate cyclohydrolase (GCH1), the rate-limiting enzyme in pterin synthesis, thereby elevating levels of biopterin. DAHP (2,4-diamino hydroxyl pyrimidine), a specific inhibitor of GCH1, prevented biopterin and NO production and invasion of E. coli K1 in HBMECs. GCH1 interaction with Ecgp96, the receptor for outer membrane protein A of E. coli K1, also increases on infection, and suppression of Ecgp96 expression prevents GCH1 activation and biopterin synthesis. Pretreatment of newborn mice with DAHP prevented the production of biopterin and the development of meningitis. These results suggest a novel role for biopterin synthesis in the pathogenesis of E. coli K1 meningitis.

Attenuation of Biopterin Synthesis Prevents Escherichia coli K1 Invasion of Brain Endothelial Cells and the Development of Meningitis in Newborn Mice

PubMed Central

Shanmuganathan, Muthusamy V.; Krishnan, Subramanian; Fu, Xiaowei; Prasadarao, Nemani V.

2013-01-01

Elevated levels of pterins and nitric oxide (NO) are observed in patients with septic shock and bacterial meningitis. We demonstrate that Escherichia coli K1 infection of human brain microvascular endothelial cells (HBMECs) induces the expression of guanosine triphosphate cyclohydrolase (GCH1), the rate-limiting enzyme in pterin synthesis, thereby elevating levels of biopterin. DAHP (2,4-diamino hydroxyl pyrimidine), a specific inhibitor of GCH1, prevented biopterin and NO production and invasion of E. coli K1 in HBMECs. GCH1 interaction with Ecgp96, the receptor for outer membrane protein A of E. coli K1, also increases on infection, and suppression of Ecgp96 expression prevents GCH1 activation and biopterin synthesis. Pretreatment of newborn mice with DAHP prevented the production of biopterin and the development of meningitis. These results suggest a novel role for biopterin synthesis in the pathogenesis of E. coli K1 meningitis. PMID:23100563

TEMPERATURE-SENSITIVE DEXTRANSUCRASE SYNTHESIS BY A LACTOBACILLUS.

PubMed

DUNICAN, L K; SEELEY, H W

1963-11-01

Dunican, L. K. (Cornell University, Ithaca, New York), and H. W. Seeley, Jr. Temperature-sensitive dextransucrase synthesis by a lactobacillus. J. Bacteriol. 86:1079-1083. 1963.-Dextran synthesis was found to be temperature-dependent in Lactobacillus strain RWM-13. Dextran was not formed above 37 C, although growth of cells occurred up to 42 C. Logarithmically growing cells transferred from 30 C to 40 C ceased producing dextran while growth decreased nominally. An examination of the extracts of cells broken by sonic treatment showed that as the temperature of growth was increased above 37 C the production of dextransucrase decreased. By use of an inhibitor of invertase, 10(-4)m AgNO(3), it was shown that invertase replaced dextransucrase activity at temperatures above 37 C. In contrast to dextransucrase in Leuconostoc mesenteroides, the enzyme in Lactobacillus strain RWM-13 was constitutive and thus resembled that of Streptococcus bovis. Thermosensitivity of dextransucrase synthesis has not been observed in Leuconostoc or Streptococcus.

Synthesis of novel 2-cyano substituted glycyrrhetinic acid derivatives as inhibitors of cancer cells growth and NO production in LPS-activated J-774 cells.

PubMed

Salomatina, Oksana V; Markov, Andrey V; Logashenko, Evgeniya B; Korchagina, Dina V; Zenkova, Marina A; Salakhutdinov, Nariman F; Vlassov, Valentin V; Tolstikov, Genrikh A

2014-01-01

Here we report the synthesis and biological activity of new semi-synthetic derivatives of naturally occurring glycyrrhetinic acid bearing a 2-cyano-3-oxo-1-en moiety in the A-ring and double bonds and carbonyl groups in the C, D and E rings. Bioassays using murine macrophage-like and tumor cells show that compound 4, which differs from Soloxolone methyl by the absence of a 9(11)-double bond in the C-ring, displays anti-inflammatory and inhibitory activities with respect to tumor cells with a high selectivity index value. Copyright © 2013 Elsevier Ltd. All rights reserved.