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.

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.

Regulation of Hyaluronan (HA) Metabolism Mediated by HYBID (Hyaluronan-binding Protein Involved in HA Depolymerization, KIAA1199) and HA Synthases in Growth Factor-stimulated Fibroblasts.

PubMed

Nagaoka, Aya; Yoshida, Hiroyuki; Nakamura, Sachiko; Morikawa, Tomohiko; Kawabata, Keigo; Kobayashi, Masaki; Sakai, Shingo; Takahashi, Yoshito; Okada, Yasunori; Inoue, Shintaro

2015-12-25

Regulation of hyaluronan (HA) synthesis and degradation is essential to maintenance of extracellular matrix homeostasis. We recently reported that HYBID (HYaluronan-Binding protein Involved in hyaluronan Depolymerization), also called KIAA1199, plays a key role in HA depolymerization in skin and arthritic synovial fibroblasts. However, regulation of HA metabolism mediated by HYBID and HA synthases (HASs) under stimulation with growth factors remains obscure. Here we report that TGF-β1, basic FGF, EGF, and PDGF-BB commonly enhance total amount of HA in skin fibroblasts through up-regulation of HAS expression, but molecular size of newly produced HA is dependent on HYBID expression levels. Stimulation of HAS1/2 expression and suppression of HYBID expression by TGF-β1 were abrogated by blockade of the MAPK and/or Smad signaling and the PI3K-Akt signaling, respectively. In normal human skin, expression of the TGF-β1 receptors correlated positively with HAS2 expression and inversely with HYBID expression. On the other hand, TGF-β1 up-regulated HAS1/2 expression but exerted only a slight suppressive effect on HYBID expression in synovial fibroblasts from the patients with osteoarthritis or rheumatoid arthritis, resulting in the production of lower molecular weight HA compared with normal skin and synovial fibroblasts. These data demonstrate that although TGF-β1, basic FGF, EGF, and PDGF-BB enhance HA production in skin fibroblasts, TGF-β1 most efficiently contributes to production of high molecular weight HA by HAS up-regulation and HYBID down-regulation and suggests that inefficient down-regulation of HYBID by TGF-β1 in arthritic synovial fibroblasts may be linked to accumulation of depolymerized HA in synovial fluids in arthritis patients. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

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.

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

Synthesis and evaluation of conformationally restricted inhibitors of aspartate semialdehyde dehydrogenase.

PubMed

Evitt, Andrew S; Cox, Russell J

2011-05-01

Inhibitors of the enzyme aspartate semialdehyde dehydrogenase, a key biological target for the generation of a new class of antibiotic compounds, have been developed. To investigate improvements to binding within an inhibitor series, the lowering of the entropic barrier to binding through conformational restriction was investigated. A library of linear and cyclic substrate analogues was generated and computational docking used to aid in structure selection. The cyclic phosphonate inhibitor 18 was thus identified as complimentary to the enzyme active-site. Synthesis and in vitro inhibition assay revealed a K(i) of 3.8 mM against natural substrate, where the linear analogue of 18, compound 15, had previously shown no inhibitory activity. Two further inhibitors, phosphate analogue diastereoisomers 17a and 17b, were synthesised and also found to have low millimolar K(i) values. As a result of the computational docking investigations, a novel substrate binding interaction was discovered: hydrogen bonding between the substrate (phosphate hydroxy-group as the hydrogen bond donor) and the NADPH cofactor (2'-oxygen as the hydrogen bond acceptor).

Imaging of Homeostatic, Neoplastic, and Injured Tissues by HA-Based Probes

PubMed Central

Veiseh, Mandana; Breadner, Daniel; Ma, Jenny; Akentieva, Natalia; Savani, Rashmin C; Harrison, Rene; Mikilus, David; Collis, Lisa; Gustafson, Stefan; Lee, Ting-Yim; Koropatnick, James; Luyt, Leonard G.; Bissell, Mina J.; Turley, Eva A.

2013-01-01

An increase in hyaluronan (HA) synthesis, cellular uptake, and metabolism occurs during the remodeling of tissue microenvironments following injury and during disease processes such as cancer. We hypothesized that multimodality HA-based probes selectively target and detectably accumulate at sites of high HA metabolism, thus providing a flexible imaging strategy for monitoring disease and repair processes. Kinetic analyses confirmed favorable available serum levels of the probe following intravenous (i.v.) or subcutaneous (s.c.) injection. Nuclear (technetium-HA, 99mTc-HA, and iodine-HA, 125I-HA), optical (fluorescent Texas Red-HA, TR-HA), and magnetic resonance (gadolinium-HA, Gd-HA) probes imaged liver (99mTc-HA), breast cancer cells/xenografts (TR-HA, Gd-HA), and vascular injury (125I-HA, TR-HA). Targeting of HA probes to these sites appeared to result from selective HA receptor-dependent localization. Our results suggest that HA-based probes, which do not require polysaccharide backbone modification to achieve favorable half-life and distribution, can detect elevated HA metabolism in homeostatic, injured, and diseased tissues. PMID:22066590

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.

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

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.

Structure-based Design and In-Parallel Synthesis of Inhibitors of AmpC b-lactamase

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

Tondi, D.; Powers, R.A.; Negri, M.C.

2010-03-08

Group I {beta}-lactamases are a major cause of antibiotic resistance to {beta}-lactams such as penicillins and cephalosporins. These enzymes are only modestly affected by classic {beta}-lactam-based inhibitors, such as clavulanic acid. Conversely, small arylboronic acids inhibit these enzymes at sub-micromolar concentrations. Structural studies suggest these inhibitors bind to a well-defined cleft in the group I {beta}-lactamase AmpC; this cleft binds the ubiquitous R1 side chain of {beta}-lactams. Intriguingly, much of this cleft is left unoccupied by the small arylboronic acids. To investigate if larger boronic acids might take advantage of this cleft, structure-guided in-parallel synthesis was used to explore newmore » inhibitors of AmpC. Twenty-eight derivatives of the lead compound, 3-aminophenylboronic acid, led to an inhibitor with 80-fold better binding (2; K{sub i} 83 nM). Molecular docking suggested orientations for this compound in the R1 cleft. Based on the docking results, 12 derivatives of 2 were synthesized, leading to inhibitors with K{sub i} values of 60 nM and with improved solubility. Several of these inhibitors reversed the resistance of nosocomial Gram-positive bacteria, though they showed little activity against Gram-negative bacteria. The X-ray crystal structure of compound 2 in complex with AmpC was subsequently determined to 2.1 {angstrom} resolution. The placement of the proximal two-thirds of the inhibitor in the experimental structure corresponds with the docked structure, but a bond rotation leads to a distinctly different placement of the distal part of the inhibitor. In the experimental structure, the inhibitor interacts with conserved residues in the R1 cleft whose role in recognition has not been previously explored. Combining structure-based design with in-parallel synthesis allowed for the rapid exploration of inhibitor functionality in the R1 cleft of AmpC. The resulting inhibitors differ considerably from {beta}-lactams but

Increased sensitivity to protein synthesis inhibitors in cells lacking tmRNA.

PubMed Central

de la Cruz, J; Vioque, A

2001-01-01

tmRNA (also known as SsrA or 10Sa RNA) is involved in a trans-translation reaction that contributes to the recycling of stalled ribosomes at the 3' end of an mRNA lacking a stop codon or at an internal mRNA cluster of rare codons. Inactivation of the ssrA gene in most bacteria results in viable cells bearing subtle phenotypes, such as temperature-sensitive growth. Herein, we report on the functional characterization of the ssrA gene in the cyanobacterium Synechocystis sp. strain PCC6803. Deletion of the ssrA gene in Synechocystis resulted in viable cells with a growth rate identical to wild-type cells. However, null ssrA cells (deltassrA) were not viable in the presence of the protein synthesis inhibitors chloramphenicol, lincomycin, spiramycin, tylosin, erythromycin, and spectinomycin at low doses that do not significantly affect the growth of wild-type cells. Sensitivity of deltassrA cells similar to wild-type cells was observed with kasugamycin, fusidic acid, thiostrepton, and puromycin. Antibiotics unrelated to protein synthesis, such as ampicillin or rifampicin, had no differential effect on the deltassrA strain. Furthermore, deletion of the ssrA gene is sufficient to impair global protein synthesis when chloramphenicol is added at sublethal concentrations for the wild-type strain. These results indicate that ribosomes stalled by some protein synthesis inhibitors can be recycled by tmRNA. In addition, this suggests that the first elongation cycle with tmRNA, which incorporates a noncoded alanine on the growing peptide chain, may have mechanistic differences with the normal elongation cycles that bypasses the block produced by these specific antibiotics. tmRNA inactivation could be an useful therapeutic target to increase the sensitivity of pathogenic bacteria against antibiotics. PMID:11780628

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

PubMed Central

Stamatopoulou, Vassiliki; Apostolidi, Maria; Li, Shuang; Lamprinou, Katerina; Papakyriakou, Athanasios

2017-01-01

Abstract Recently, it was discovered that exposure to mainstream antibiotics activate numerous bacterial riboregulators that control antibiotic resistance genes including metabolite-binding riboswitches and other transcription attenuators. However, the effects of commonly used antibiotics, many of which exhibit RNA-binding properties, on the widespread T-box riboswitches, remain unknown. In Staphylococcus aureus, a species-specific glyS T-box controls the supply of glycine for both ribosomal translation and cell wall synthesis, making it a promising target for next-generation antimicrobials. Here, we report that specific protein synthesis inhibitors could either significantly increase T-box-mediated transcription antitermination, while other compounds could suppress it, both in vitro and in vivo. In-line probing of the full-length T-box combined with molecular modelling and docking analyses suggest that the antibiotics that promote transcription antitermination stabilize the T-box:tRNA complex through binding specific positions on stem I and the Staphylococcal-specific stem Sa. By contrast, the antibiotics that attenuate T-box transcription bind to other positions on stem I and do not interact with stem Sa. Taken together, our results reveal that the transcription of essential genes controlled by T-box riboswitches can be directly modulated by commonly used protein synthesis inhibitors. These findings accentuate the regulatory complexities of bacterial response to antimicrobials that involve multiple riboregulators. PMID:28973457

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

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

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.

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.

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

Thromboxane synthesis inhibitors and postprandial jejunal capillary exchange capacity.

PubMed

Mangino, M J; Chou, C C

1988-05-01

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

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.

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

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

PubMed

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

2017-09-29

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

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.

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.

Wounding-induced synthesis of hyaluronic acid in organotypic epidermal cultures requires the release of heparin-binding egf and activation of the EGFR.

PubMed

Monslow, James; Sato, Nobuyuki; Mack, Judith A; Maytin, Edward V

2009-08-01

Hyaluronic acid (HA), a glycosaminoglycan located between keratinocytes in the epidermis, accumulates dramatically following skin wounding. To study inductive mechanisms, a rat keratinocyte organotypic culture model that faithfully mimics HA metabolism was used. Organotypic cultures were needle-punctured 100 times, incubated for up to 24 hours, and HA analyzed by histochemical and biochemical methods. Within 15 minutes post-injury, HA levels had elevated two-fold, increasing to four-fold by 24 hours. HA elevations far from the site of injury suggested the possible involvement of a soluble HA-inductive factor. Media transfer experiments (from wounded cultures to unwounded cultures) confirmed the existence of a soluble factor. From earlier evidence, we hypothesized that an EGF-like growth factor might be responsible. This was confirmed as follows: (1) EGFR kinase inhibitor (AG1478) completely prevented wounding-induced HA accumulation. (2) Rapid tyrosine-phosphorylation of EGFR correlated well with the onset of increased HA synthesis. (3) A neutralizing antibody that recognizes heparin binding EGF-like growth factor (HB-EGF) blocked wounding-induced HA synthesis by > or =50%. (4) Western analyses showed that release of activated HB-EGF (but neither amphiregulin nor EGF) occured after wounding. In summary, rapid HA accumulation after epidermal wounding occurs through a mechanism requiring cleavage of HB-EGF and activation of EGFR signaling.

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.

HDPE-HA composites synthetized by in situ polymerization with different filler content

NASA Astrophysics Data System (ADS)

Hermán, V.; Karam, A.; Albano, C.; Romero, K.; González, G.

2012-07-01

In Situ ethylene polymerization was used to synthesize high density polyethylene - hydroxyapatite (HDPE-HA) composites, employing Cp2ZrCl2/MAO as catalytic system. A good dispersion of HA into the HDPE matrix was obtained when the following synthesis conditions were combined: high stirring velocities (2000 rpm), low quantities of solvent (100 mL), and 10 °C. Under these conditions different filler content was used to synthetized HDPE-HA composites. An interaction between HA and HDPE was obtained by FTIR. On the other hand, thermal analysis indicated that no significant differences were observed between HDPE and the composites.

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

PubMed

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

2015-12-15

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

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.

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

PubMed

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

2017-07-13

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

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.

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

Pepsin-solubilised collagen (PSC) from Red Sea cucumber (Stichopus japonicus) regulates cell cycle and the fibronectin synthesis in HaCaT cell migration.

PubMed

Park, Soo-Yeong; Lim, Hee Kyoung; Lee, Seogjae; Hwang, Hyeong Cheol; Cho, Somi K; Cho, Moonjae

2012-05-01

Pepsin-solubilised collagen (PSC) from Red Sea cucumber (Stichopus japonicus) was studied with respect to its wound-healing effects on a human keratinocyte (HaCaT) cell line. Disaggregated collagen fibres were treated with 0.1M NaOH for 24h and digested with pepsin for 72h to reach maximum yield of 26.6%. The results of an in vitro wound-healing test showed that migration of HaCaT cells was 1.5-fold faster on PSC-coated plates than on untreated plates. The migration rate of sea cucumber PSC was similar to that of rat PSC, but five times higher than that of bovine gelatin. HaCaT cells grown on PSC-coated plates revealed increased fibronectin synthesis (6-fold and 3-fold compared to gelatin and rat PSC, respectively). Additionally, sea cucumber PSCs induced HaCaT cell proliferation by decreasing the G1 phase by 5% and maintaining a larger population (8%) of cells in mitosis. Collagen from Red Sea cucumber might be useful as an alternative to mammalian collagen in the nutraceutical and pharmaceutical industries. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Recombinant factor concentrates may increase inhibitor development: a single centre cohort study.

PubMed

Strauss, T; Lubetsky, A; Ravid, B; Bashari, D; Luboshitz, J; Lalezari, S; Misgav, M; Martinowitz, U; Kenet, G

2011-07-01

Recent reports have raised concerns regarding potential risk factors for inhibitor development. In Israel, all haemophilia patients (n = 479) are followed by the National Hemophilia Center. Most children are neonatally exposed to factor concentrate (due to circumcision performed at the age of 8 days). The impact of early exposure and recombinant FVIII products (rFVIII) administration (approved in Israel since 1996) upon inhibitor occurrence in our cohort of haemophilia A (HA) patients was analysed. Two hundred ninety-two consecutive paediatric cases with a first symptomatic onset of HA were enrolled and followed over a median time of 7 years [min-max: 9 months to 17 years]. Study endpoint was inhibitor development against factor VIII. In addition, the treatment regimens applied, i.e. bolus administration or 'continuous infusion' and the family history of inhibitor development were investigated. During the follow-up period 31/292 children (10.6%) developed high titre inhibitors. Inhibitors occurred in 14/43 (32.5%) HA patients neonatally exposed to rFVIII, as compared to 22/249 previously treated with Plasma Derived (PD) products (8.8%). The odds ratio for inhibitor formation in rFVIII treated HA patients was 3.43 (95% CI: 1.36-8.65). Transient inhibitor evolved among 2/43 paediatric HA patients, only among those treated with rFVIII. The risk of inhibitor detection significantly increased among HA children treated by continuous infusion (P = 0.025). Our experience shows that the risk of inhibitor formation may be increased by early exposure to recombinant concentrates. The multiple variables affecting inhibitor incidence deserve further attention by larger prospective studies. © 2011 Blackwell Publishing Ltd.

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.

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.

Enantioselective Synthesis and Profiling of Two Novel Diazabicyclooctanone β-Lactamase Inhibitors

PubMed Central

2014-01-01

The enantioselective synthesis of two novel cyclopropane-fused diazabicyclooctanones is reported here. Starting from butadiene monoxide, the key enone intermediate 7 was prepared in six steps. Subsequent stereoselective introduction of the cyclopropane group and further transformation led to compounds 1a and 1b as their corresponding sodium salt. The great disparity regarding their hydrolytic stability was rationalized by the steric interaction between the cyclopropyl methylene and urea carbonyl. These two novel β-lactamase inhibitors were active against class A, C, and D enzymes. PMID:25313328

Synthesis and evaluation of chalcone analogues based pyrimidines as angiotensin converting enzyme inhibitors.

PubMed

Bukhari, S N A; Butt, A M; Amjad, M W B; Ahmad, W; Shah, V H; Trivedi, A R

2013-11-01

Hypertension is a widespread and frequently progressive ailment that imparts a foremost threat for cardiovascular and renal disorders. Mammoth efforts are needed for the synthesis of innovative antihypertensive agents to combat this lethal disease. Chalcones have shown antihypertensive activity through inhibition of Angiotensin Converting Enzyme (ACE). Hence, a series of chalcone analogues is synthesized and used as precursor for the synthesis of novel series of pyrimidines. Precursor chalcones were prepared by reacting aldehydes and ketones in presence of sodium hydroxide followed by synthesis of corresponding pyrimidines by reaction with urea in presence of potassium hydroxide. Both groups were then evaluated for their effects on ACE. The results depicted that pyrimidines were more active than chalcones with methoxy (C5 and P5) substitution showing best results to inhibit ACE. Given that chalcone analogues and pyrimidines show a potential as the angiotensin converting enzyme inhibitors.

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.

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.

Identification and Characterization of Influenza Virus Entry Inhibitors through Dual Myxovirus High-Throughput Screening.

PubMed

Weisshaar, Marco; Cox, Robert; Morehouse, Zachary; Kumar Kyasa, Shiva; Yan, Dan; Oberacker, Phil; Mao, Shuli; Golden, Jennifer E; Lowen, Anice C; Natchus, Michael G; Plemper, Richard K

2016-08-15

Influenza A virus (IAV) infections cause major morbidity and mortality, generating an urgent need for novel antiviral therapeutics. We recently established a dual myxovirus high-throughput screening protocol that combines a fully replication-competent IAV-WSN strain and a respiratory syncytial virus reporter strain for the simultaneous identification of IAV-specific, paramyxovirus-specific, and broad-spectrum inhibitors. In the present study, this protocol was applied to a screening campaign to assess a diverse chemical library with over 142,000 entries. Focusing on IAV-specific hits, we obtained a hit rate of 0.03% after cytotoxicity testing and counterscreening. Three chemically distinct hit classes with nanomolar potency and favorable cytotoxicity profiles were selected. Time-of-addition, minigenome, and viral entry studies demonstrated that these classes block hemagglutinin (HA)-mediated membrane fusion. Antiviral activity extends to an isolate from the 2009 pandemic and, in one case, another group 1 subtype. Target identification through biolayer interferometry confirmed binding of all hit compounds to HA. Resistance profiling revealed two distinct escape mechanisms: primary resistance, associated with reduced compound binding, and secondary resistance, associated with unaltered binding. Secondary resistance was mediated, unusually, through two different pairs of cooperative mutations, each combining a mutation eliminating the membrane-proximal stalk N-glycan with a membrane-distal change in HA1 or HA2. Chemical synthesis of an analog library combined with in silico docking extracted a docking pose for the hit classes. Chemical interrogation spotlights IAV HA as a major druggable target for small-molecule inhibition. Our study identifies novel chemical scaffolds with high developmental potential, outlines diverse routes of IAV escape from entry inhibition, and establishes a path toward structure-aided lead development. This study is one of the first to apply a

Identification and Characterization of Influenza Virus Entry Inhibitors through Dual Myxovirus High-Throughput Screening

PubMed Central

Weisshaar, Marco; Cox, Robert; Morehouse, Zachary; Kumar Kyasa, Shiva; Yan, Dan; Oberacker, Phil; Mao, Shuli; Lowen, Anice C.; Natchus, Michael G.

2016-01-01

ABSTRACT Influenza A virus (IAV) infections cause major morbidity and mortality, generating an urgent need for novel antiviral therapeutics. We recently established a dual myxovirus high-throughput screening protocol that combines a fully replication-competent IAV-WSN strain and a respiratory syncytial virus reporter strain for the simultaneous identification of IAV-specific, paramyxovirus-specific, and broad-spectrum inhibitors. In the present study, this protocol was applied to a screening campaign to assess a diverse chemical library with over 142,000 entries. Focusing on IAV-specific hits, we obtained a hit rate of 0.03% after cytotoxicity testing and counterscreening. Three chemically distinct hit classes with nanomolar potency and favorable cytotoxicity profiles were selected. Time-of-addition, minigenome, and viral entry studies demonstrated that these classes block hemagglutinin (HA)-mediated membrane fusion. Antiviral activity extends to an isolate from the 2009 pandemic and, in one case, another group 1 subtype. Target identification through biolayer interferometry confirmed binding of all hit compounds to HA. Resistance profiling revealed two distinct escape mechanisms: primary resistance, associated with reduced compound binding, and secondary resistance, associated with unaltered binding. Secondary resistance was mediated, unusually, through two different pairs of cooperative mutations, each combining a mutation eliminating the membrane-proximal stalk N-glycan with a membrane-distal change in HA1 or HA2. Chemical synthesis of an analog library combined with in silico docking extracted a docking pose for the hit classes. Chemical interrogation spotlights IAV HA as a major druggable target for small-molecule inhibition. Our study identifies novel chemical scaffolds with high developmental potential, outlines diverse routes of IAV escape from entry inhibition, and establishes a path toward structure-aided lead development. IMPORTANCE This study is one of

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.

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.

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

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.

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.

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.

Trypanosoma cruzi H+-ATPase 1 (TcHA1) and 2 (TcHA2) genes complement yeast mutants defective in H+ pumps and encode plasma membrane P-type H+-ATPases with different enzymatic properties.

PubMed

Luo, Shuhong; Scott, David A; Docampo, Roberto

2002-11-15

Previous studies in Trypanosoma cruzi have shown that intracellular pH homeostasis requires ATP and is affected by H(+)-ATPase inhibitors, indicating a major role for ATP-driven proton pumps in intracellular pH control. In the present study, we report the cloning and sequencing of a pair of genes linked in tandem (TcHA1 and TcHA2) in T. cruzi which encode proteins with homology to fungal and plant P-type proton-pumping ATPases. The genes are expressed at the mRNA level in different developmental stages of T. cruzi: TcHA1 is expressed maximally in epimastigotes, whereas TcHA2 is expressed predominantly in trypomastigotes. The proteins predicted from the nucleotide sequence of the genes have 875 and 917 amino acids and molecular masses of 96.3 and 101.2 kDa, respectively. Full-length TcHA1 and an N-terminal truncated version of TcHA2 complemented a Saccharomyces cerevisiae strain deficient in P-type H(+)-ATPase activity, the proteins localized to the yeast plasma membrane, and ATP-driven proton pumping could be detected in proteoliposomes reconstituted from plasma membrane purified from transfected yeast. The reconstituted proton transport activity was reduced by inhibitors of P-type H(+)-ATPases. C-terminal truncation did not affect complementation of mutant yeast, suggesting the lack of C-terminal autoinhibitory domains in these proteins. ATPase activity in plasma membrane from TcHA1- and (N-terminal truncated) TcHA2-transfected yeast was inhibited to different extents by vanadate, whereas the latter yeast strain was more resistant to extremes of pH, suggesting that the native proteins may serve different functions at different stages in the T. cruzi life cycle.

New associations: INFG and TGFB1 genes and the inhibitor development in severe haemophilia A.

PubMed

de Alencar, J B; Macedo, L C; de Barros, M F; Rodrigues, C; Shinzato, A H; Pelissari, C B; Machado, J; Sell, A M; Visentainer, J E L

2015-07-01

The development of factor VIII (FVIII) inhibitor is the main complication of replacement therapy in patients with haemophilia A (HA). A ratio of 5-7% of individuals HA develops antibodies (inhibitors) against the FVIII infused during the treatment, thereby reducing their pro-coagulant activity. The immunomodulatory cytokine genes have been related to the risk of development of alloantibodies in several studies, mainly in HA with severe form. We investigated the polymorphisms in regulatory regions of cytokine genes (IL1A, IL1B, IL1R, IL1RA, IL4RA, IL12, INFG, TGFB1, TNF, IL2, IL4, IL6, IL10) that could influence the risk of developing inhibitors in patients with severe HA. The genotyping of cytokine genes of 117 patients with HA was performed by polymerase chain reaction with sequence-specific primers (PCR-SSP) using the protocol recommended by the manufacturer (Invitrogen kit Cytokines(®) , Canoga Park, USA) RESULTS: From the cohort of 117 patients with severe HA, 35 developed inhibitors. There was a higher frequency of +874 T allele in INFG and of +869 TT and TG/TG in TGFB1 genes on patients with inhibitors. This suggests that polymorphisms in INFG and in TGFB1 genes are related to risk of developing inhibitor, and could contribute to a genetic profile of the individual HA for the risk of inhibitors development to FVIII. © 2015 John Wiley & Sons Ltd.

Inhibitor development and mortality in non-severe hemophilia A.

PubMed

Eckhardt, C L; Loomans, J I; van Velzen, A S; Peters, M; Mauser-Bunschoten, E P; Schwaab, R; Mazzucconi, M G; Tagliaferri, A; Siegmund, B; Reitter-Pfoertner, S E; van der Bom, J G; Fijnvandraat, K

2015-07-01

The life expectancy of non-severe hemophilia A (HA) patients equals the life expectancy of the non-hemophilic population. However, data on the effect of inhibitor development on mortality and on hemophilia-related causes of death are scarce. The development of neutralizing factor VIII antibodies in non-severe HA patients may dramatically change their clinical outcome due to severe bleeding complications. We assessed the association between the occurrence of inhibitors and mortality in patients with non-severe HA. In this retrospective cohort study, clinical data and vital status were collected for 2709 non-severe HA patients (107 with inhibitors) who were treated between 1980 and 2011 in 34 European and Australian centers. Mortality rates for patients with and without inhibitors were compared. During 64,200 patient-years of follow-up, 148 patients died (mortality rate, 2.30 per 1000 person-years; 95% confidence interval (CI), 1.96-2.70) at a median age of 64 years (interquartile range [IQR], 49-76). In 62 patients (42%) the cause of death was hemophilia related. Sixteen inhibitor patients died at a median age of 71 years (IQR, 60-81). In ten patients the inhibitor was present at time of death; seven of them died of severe bleeding complications. The all-cause mortality rate in inhibitor patients was > 5 times increased compared with that for those without inhibitors (age-adjusted mortality rate ratio, 5.6). Inhibitor development in non-severe hemophilia is associated with increased mortality. High rates of hemophilia-related mortality in this study indicate that non-severe hemophilia is not mild at all and stress the importance of close follow-up for these patients. © 2015 International Society on Thrombosis and Haemostasis.

New Coll-HA/BT composite materials for hard tissue engineering.

PubMed

Zanfir, Andrei Vlad; Voicu, Georgeta; Busuioc, Cristina; Jinga, Sorin Ion; Albu, Madalina Georgiana; Iordache, Florin

2016-05-01

The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen-hydroxyapatite/barium titanate (Coll-HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol-gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll-HA and Coll-HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll-HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT. Copyright © 2016 Elsevier B.V. All rights reserved.

Biopolymers for Medical Applications: Polyglycerol Sebacate (PGS) doped Hydroxyapatite (HA)

NASA Astrophysics Data System (ADS)

Teruel, Maria; Kuthirummal, Narayanan; Levi, Nicole; Wake College Team

2011-04-01

In the investigation to engineer the ideal scaffolding device for cleft palate repair, polyglycerol sebacate (PGS) doped with hydroxyapatite (HA) were chosen for their elastomeric and biodegradable properties, as well as their cost-effective synthesis. Hydroxyapatite was integrated into the PGS to form a composite with high porosity and improved mechanical properties yielding a good substrate for cell attachment during the repair process. FT-IR scans were performed to characterize the composite polymer. Differential Scanning Calorimetry (DSC) was utilized to identify an acceptable glass transition temperature (Tg), between -18 and - 21°C. At this Tg, it was determined that the material was sufficiently polymerized to a point where it was durable yet pliable enough to use for cleft palate devices. In the synthesis of PGS 3% and 5% HA, a Tg of - 20.10°C and - 21.72°C, respectively, was achieved and further analytical tests were then performed on the polymers. Methods of analysis included X-Ray Diffraction and Tensile Strength Testing. Acknowledgements to the Research Department of Plastic and Reconstructive Surgery, Wake Forest University and College of Charleston.

Discovery of potent KIFC1 inhibitors using a method of integrated high-throughput synthesis and screening.

PubMed

Yang, Bin; Lamb, Michelle L; Zhang, Tao; Hennessy, Edward J; Grewal, Gurmit; Sha, Li; Zambrowski, Mark; Block, Michael H; Dowling, James E; Su, Nancy; Wu, Jiaquan; Deegan, Tracy; Mikule, Keith; Wang, Wenxian; Kaspera, Rüdiger; Chuaqui, Claudio; Chen, Huawei

2014-12-11

KIFC1 (HSET), a member of the kinesin-14 family of motor proteins, plays an essential role in centrosomal bundling in cancer cells, but its function is not required for normal diploid cell division. To explore the potential of KIFC1 as a therapeutic target for human cancers, a series of potent KIFC1 inhibitors featuring a phenylalanine scaffold was developed from hits identified through high-throughput screening (HTS). Optimization of the initial hits combined both design-synthesis-test cycles and an integrated high-throughput synthesis and biochemical screening method. An important aspect of this integrated method was the utilization of DMSO stock solutions of compounds registered in the corporate compound collection as synthetic reactants. Using this method, over 1500 compounds selected for structural diversity were quickly assembled in assay-ready 384-well plates and were directly tested after the necessary dilutions. Our efforts led to the discovery of a potent KIFC1 inhibitor, AZ82, which demonstrated the desired centrosome declustering mode of action in cell studies.

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.

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.

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

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.

Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice.

PubMed

Rashid, Davood; Panda, B P; Vohora, Divya

2015-11-01

Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acetobixan, an Inhibitor of Cellulose Synthesis Identified by Microbial Bioprospecting

PubMed Central

Xia, Ye; Lei, Lei; Brabham, Chad; Stork, Jozsef; Strickland, James; Ladak, Adam; Gu, Ying; Wallace, Ian; DeBolt, Seth

2014-01-01

In plants, cellulose biosynthesis is an essential process for anisotropic growth and therefore is an ideal target for inhibition. Based on the documented utility of small-molecule inhibitors to dissect complex cellular processes we identified a cellulose biosynthesis inhibitor (CBI), named acetobixan, by bio-prospecting among compounds secreted by endophytic microorganisms. Acetobixan was identified using a drug-gene interaction screen to sift through hundreds of endophytic microbial secretions for one that caused synergistic reduction in root expansion of the leaky AtcesA6prc1-1 mutant. We then mined this microbial secretion for compounds that were differentially abundant compared with Bacilli that failed to mimic CBI action to isolate a lead pharmacophore. Analogs of this lead compound were screened for CBI activity, and the most potent analog was named acetobixan. In living Arabidopsis cells visualized by confocal microscopy, acetobixan treatment caused CESA particles localized at the plasma membrane (PM) to rapidly re-localize to cytoplasmic vesicles. Acetobixan inhibited 14C-Glc uptake into crystalline cellulose. Moreover, cortical microtubule dynamics were not disrupted by acetobixan, suggesting specific activity towards cellulose synthesis. Previous CBI resistant mutants such as ixr1-2, ixr2-1 or aegeus were not cross resistant to acetobixan indicating that acetobixan targets a different aspect of cellulose biosynthesis. PMID:24748166

HA-1077 inhibits cell migration/invasion of oral squamous cell carcinoma.

PubMed

Moreira Carboni, Simone de Sales Costa; Rodrigues Lima, Nathália Alves; Pinheiro, Nanci Mendes; Tavares-Murta, Beatriz Martins; Crema, Virgínia Oliveira

2015-10-01

Oral squamous cell carcinoma (OSCC) is the most malignant lesion occurring in the head and neck. The Rho-kinases (ROCKs), effectors of Rho proteins, are involved in actin cytoskeletal organization, cell migration, and maintenance cortex. The HA-1077 inhibits the ROCKs. This study aimed to evaluate the effect of treatment with HA-1077 on cell motility in SCC-4 cells, a cell line originating from human OSCC. F-actin of SCC-4 cells treated or not with HA-1077 (1, 50 and 100 μmol/l), and also HA-1077 50 μmol/l and/or inhibitors Y-27632 30 μmol/l was stained with rhodamine-conjugated phalloidin and analyzed by confocal microscopy. Approximately 1×10 cells/well, control and treated with HA-1077 (25, 50, and 100 μmol/l) were added to the migration plate assay. In addition, 1×10 cells/well, control and treated with HA-1077 50 μmol/l, were tested by invasion assays (plate coated with Matrigel). The inhibition of ROCKs with HA-1077 and/or Y-27632 leads to morphological changes, affecting the organization of the actin. The inhibitory effect of HA-1077 (P<0.0001) was dose dependent as the number of cells migrated at 100 μmol/l was statistically different: 25 μmol/l (P<0.0001) and 50 μmol/l (P<0.01). The number of cells treated with HA-1077 50 μmol/l decreased compared with control cells that invaded through Matrigel (P<0.0001). This study shows an inhibitory effect of HA-1077 on cell migration and invasion, suggesting that the use of HA-1077 can be a potential therapy for OSCC.

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.

Inhibition of hyaluronan synthesis by vesnarinone in cultured human myofibroblasts.

PubMed

Ueki, N; Taguchi, T; Takahashi, M; Adachi, M; Ohkawa, T; Amuro, Y; Hada, T; Higashino, K

2000-02-02

Hyaluronan (HA), which is a major component of the extracellular matrix (ECM), is regulated during myofibroproliferative responses to numerous forms of inflammatory stimuli. It is a key factor involved in cellular migration and adherence. The development of a potent and non-toxic inhibitor of HA synthesis would open up a new avenue for the treatment of fibrocontractive diseases such as pulmonary fibrosis and liver cirrhosis. In this study, the effects of vesnarinone (OPC-8212: 3,4-dihydro-6-[4-(3, 4-dimethoxybenzoyl)-1-piperazinyl]-2(1H)-quinolinone) on the secretion of HA in human myofibroblast cell lines (MRC-5 and LI90 cells, referred to as pulmonary and hepatic myofibroblasts, respectively) were examined. Vesnarinone specifically and dose-dependently inhibited HA secretion by myofibroblasts up-regulated by fetal calf serum (FCS). The treatment of vesnarinone did not modify the phenotype of myofibroblast cells in culture. Vesnarinone also potently inhibited the HA secretion by the two myofibroblast cell lines up-regulated by transforming growth factor-beta1 (TGF-beta1) or tumor necrosis factor-alpha (TNF-alpha). The addition of vesnarinone to myofibroblasts resulted in a significant decrease of HA synthase (HAS) activity, with or without the addition of FCS or either cytokine. These findings suggest that vesnarinone inhibits the secretion of HA in myofibroblasts by specifically suppressing HAS activity, and may therefore prove useful for the treatment of chronic inflammation and tissue fibrosis.

Low-concentration vemurafenib induces the proliferation and invasion of human HaCaT keratinocytes through mitogen-activated protein kinase pathway activation.

PubMed

Roh, Mi Ryung; Kim, Jung Min; Lee, Sang Hee; Jang, Hong Sun; Park, Kyu Hyun; Chung, Kee Yang; Rha, Sun Young

2015-09-01

Cutaneous squamous cell carcinomas and keratoacanthomas commonly occur in patients treated with BRAF inhibitors. We investigated the effect of the BRAF inhibitor vemurafenib on normal immortalized human HaCaT keratinocytes to explore the mechanism of hyperproliferative cutaneous neoplasia associated with the use of BRAF inhibitors. Vemurafenib induced an increase in viable cell number in BRAF wild-type cell lines (SK-MEL-2 and HaCaT) but not in BRAF mutant cell lines (SK-MEL-24 and G361). In HaCaT keratinocytes, a low concentration (2 μmol/L) of vemurafenib increased cell proliferation and activated mitogen-activated protein kinase kinase/extracellular signal-regulated kinase in a CRAF-dependent manner. Invasiveness of HaCaT cells in a Matrigel assay significantly increased upon cultivation of cells with 2 μmol/L vemurafenib for 24 h. Gelatin zymography, reverse transcription polymerase chain reaction and western blot results revealed that 2 μmol/L vemurafenib treatment increased matrix metalloproteinase (MMP)-2 and MMP-9 expressions and activities in HaCaT cells. These results offer additional insight into the complex mechanism of paradoxical mitogen-activated protein kinase signaling involved in hyperproliferative cutaneous neoplasias that arise after BRAF inhibition and suggest a possible role for MMP in tumor progression and invasion. © 2015 Japanese Dermatological Association.

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.

Antipyrimidine effects of five different pyrimidine de novo synthesis inhibitors in three head and neck cancer cell lines.

PubMed

Peters, Godefridus J

2018-05-03

The pyrimidine de novo nucleotide synthesis consists of 6 sequential steps. Various inhibitors against these enzymes have been developed and evaluated in the clinic for their potential anticancer activity: acivicin inhibits carbamoyl-phosphate-synthase-II, N-(phosphonacetyl)-L- aspartate (PALA) inhibits aspartate-transcarbamylase, Brequinar sodium and dichloroallyl-lawsone (DCL) inhibit dihydroorotate-dehydrogenase, and pyrazofurin (PF) inhibits orotate-phosphoribosyltransferase. We compared their growth inhibition against 3 cell lines from head-and-neck-cancer (HEP-2, UMSCC-14B and UMSCC-14C) and related the sensitivity to their effects on nucleotide pools. In all cell lines Brequinar and PF were the most active compounds with IC50 (50% growth inhibition) values between 0.06-0.37 µM, Acivicin was as potent (IC50s 0.26-1 µM), but DCL was 20-31-fold less active. PALA was most inactive (24-128 µM). At equitoxic concentrations, all pure antipyrimidine de novo inhibitors depleted UTP and CTP after 24 hr exposure, which was most pronounced for Brequinar (between 6-10% of UTP left, and 12-36% CTP), followed by DCL and PF, which were almost similar (6-16% UTP and 12-27% CTP), while PALA was the least active compound (10-70% UTP and 13-68% CTP). Acivicin is a multi-target inhibitor of more glutamine requiring enzymes (including GMP synthetase) and no decrease of UTP was found, but a pronounced decrease in GTP (31-72% left). In conclusion, these 5 inhibitors of the pyrimidine de novo nucleotide synthesis varied considerably in their efficacy and effect on pyrimidine nucleotide pools. Inhibitors of DHO-DH were most effective suggesting a primary role of this enzyme in controlling pyrimidine nucleotide pools.

Efficient Synthesis and Discovery of Schiff Bases as Potent Cholinesterase Inhibitors.

PubMed

Razik, Basma M Abd; Osman, Hasnah; Ezzat, Mohammed O; Basiri, Alireza; Salhin, Abdussalam; Kia, Yalda; Murugaiyah, Vikneswaran

2016-01-01

The search for new cholinesterase inhibitors is still a promising approach for management of Alzheimer`s disease. Schiff bases are considered as important class of organic compounds, which have wide range of applications including as enzyme inhibitors. In the present study, a new green ionic liquid mediated strategy was developed for convenient synthesis of two series of Schiff bases 3(a-j) and 5(a-j) as potential cholinesterase inhibitors using aromatic aldehydes and primary amines in [bmim]Br. The synthesized compounds were evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential by modified Ellman's method. The molecular interactions between the most active compound and the enzyme were analyzed by molecular docking. Among them, 3j displayed higher inhibitory activities than reference drug, galanthamine, with IC50 values of 2.05 and 5.77 µM, for AChE and BChE, respectively. Interestingly, all the compounds except 3b displayed higher BChE inhibitions than galanthamine with IC50 values ranging from 5.77 to 18.52 µM. Molecular docking of compound 3j inside the TcAChE and hBChE completely coincided with the inhibitory activities observed. The compound forms strong hydrogen bonding at the peripheral anionic site of AChE whereas on BChE, it had hydrophobic and mild polar interactions. An efficient and eco-friendly synthetic methodology has been developed to synthesize Schiff bases in a very short reaction time and excellent yields in ionic solvent, whereby the compounds from series 3 showed promising cholinesterase inhibitory activity.

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.

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

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.

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.

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.

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

In-vitro Wound Healing Effect of 15-Hydroxyprostaglandin Dehydrogenase Inhibitor from Plant

PubMed Central

Karna, Sandeep

2017-01-01

Background: Prostaglandins (PGs) have short existence in vivo because they are rapidly metabolized by NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) to 15-ketoprostaglandins. Inhibition of 15-PGDH causes elevated level of PGE2 in cellular system. It will be valuable for the therapeutic management of diseases requiring elevated PGE2 levels, like wound healing. Objective: Ninety-eight plant samples were screened for the discovery of potent 15-PGDH inhibitor. Among them, top five plant extracts as potent 15-PGDH inhibitor were chosen to determine PGE2 release from HaCaT (Keratinocyte cell line) cell line. Finally, top 15-PGDH inhibitor was selected to evaluate in vitro wound healing effect on HaCaT scratch model. Method: The inhibitory activity for 15-PGDH inhibitors was evaluated using fluorescence spectrophotometer by measuring the formation of NADH at 468 nm following excitation at 340 nm. Cell viability assay and PGE2 release was evaluated in HaCaT cell line after treatment of 15-PGDH inhibitors. Scratches were made using sterile 200 μL on HaCaT cell and wound-healing effect was evaluated after treatment of 15-PGDH inhibitor. Results: 15-PGDH inhibitors elevated PGE2 levels in concentration-dependent manner. Ethanol extract of Artocarpus heterophyllus (EEAH), the most potent 15-PGDH inhibitor (IC50 = 0.62 µg/mL) with least cytotoxicity (IC50 = 670 µg/ml), elevated both intracellular and extracellular PGE2 levels. EEAH facilitated in-vitro wound healing in a HaCaT (Keratinocyte cell line) scratch model. Conclusion: EEAH might apply to treat dermal wounds by elevating PGE2 levels via COX-1 induction and 15-PGDH inhibition. SUMMARY Biological inactivation of 15-PGDH causes elevated level of PGE2 which will be useful for the management of disease that requires elevated level of PGE2. Abbreviations used: 15-PGDH: 15-hydroxyprostaglandin dehydrogenase, COX: Cyclooxygenase, DTT: Dithiothreitol, DMEM: Dulbecco's modified Eagle's media, EEAH: Ethanol

In-vitro Wound Healing Effect of 15-Hydroxyprostaglandin Dehydrogenase Inhibitor from Plant.

PubMed

Karna, Sandeep

2017-01-01

Prostaglandins (PGs) have short existence in vivo because they are rapidly metabolized by NAD + -dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) to 15-ketoprostaglandins. Inhibition of 15-PGDH causes elevated level of PGE 2 in cellular system. It will be valuable for the therapeutic management of diseases requiring elevated PGE 2 levels, like wound healing. Ninety-eight plant samples were screened for the discovery of potent 15-PGDH inhibitor. Among them, top five plant extracts as potent 15-PGDH inhibitor were chosen to determine PGE 2 release from HaCaT (Keratinocyte cell line) cell line. Finally, top 15-PGDH inhibitor was selected to evaluate in vitro wound healing effect on HaCaT scratch model. The inhibitory activity for 15-PGDH inhibitors was evaluated using fluorescence spectrophotometer by measuring the formation of NADH at 468 nm following excitation at 340 nm. Cell viability assay and PGE 2 release was evaluated in HaCaT cell line after treatment of 15-PGDH inhibitors. Scratches were made using sterile 200 μL on HaCaT cell and wound-healing effect was evaluated after treatment of 15-PGDH inhibitor. 15-PGDH inhibitors elevated PGE 2 levels in concentration-dependent manner. Ethanol extract of Artocarpus heterophyllus (EEAH), the most potent 15-PGDH inhibitor (IC 50 = 0.62 µg/mL) with least cytotoxicity (IC 50 = 670 µg/ml), elevated both intracellular and extracellular PGE 2 levels. EEAH facilitated in-vitro wound healing in a HaCaT (Keratinocyte cell line) scratch model. EEAH might apply to treat dermal wounds by elevating PGE 2 levels via COX-1 induction and 15-PGDH inhibition. Biological inactivation of 15-PGDH causes elevated level of PGE 2 which will be useful for the management of disease that requires elevated level of PGE 2 . Abbreviations used: 15-PGDH: 15-hydroxyprostaglandin dehydrogenase, COX: Cyclooxygenase, DTT: Dithiothreitol, DMEM: Dulbecco's modified Eagle's media, EEAH: Ethanol extract of Artocarpus heterophyllus, MRP4

Synthesis of Chromone, Quinolone, and Benzoxazinone Sulfonamide Nucleosides as Conformationally Constrained Inhibitors of Adenylating Enzymes Required for Siderophore Biosynthesis

PubMed Central

Engelhart, Curtis A.; Aldrich, Courtney C.

2013-01-01

MbtA catalyzes the first committed step of mycobactin biosynthesis in Mycobacterium tuberculosis (Mtb) and is responsible for the incorporation of salicylic acid into the mycobactin siderophores. 5′-O-[N-(Salicyl)sulfamoyl]adenosine (Sal-AMS) is an extremely potent nucleoside inhibitor of MbtA that possesses excellent activity against whole-cell Mtb, but suffers from poor bioavailability. In an effort to improve the bioavailability, we have designed four conformationally constrained analogues of Sal-AMS that remove two rotatable bonds and the ionized sulfamate group based on computational and structural studies. Herein we describe the synthesis, biochemical, and microbiological evaluation of chromone-, quinolone-, and benzoxazinone-3-sulfonamide derivatives of Sal-AMS. We developed new chemistry to assemble these three heterocycles from common β-ketosulfonamide intermediates. The synthesis of the chromone- and quinolone-3-sulfonamide intermediates features formylation of a β-ketosulfonamide employing dimethylformamide dimethyl acetal to afford an enaminone that can react intramolecularly with a phenol or intermolecularly with a primary amine via addition-elimination reaction(s). The benzoxazinone-3-sulfonamide was prepared by nitrosation of a β-ketosulfonamide followed by intramolecular nucleophilic aromatic substitution. Mitsunobu coupling of these bicyclic sulfonamides with a protected adenosine derivative followed by global deprotection provides a concise synthesis of the respective inhibitors. PMID:23805993

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.

Microwave-assisted synthesis of novel purine nucleosides as selective cholinesterase inhibitors.

PubMed

Schwarz, S; Csuk, R; Rauter, A P

2014-04-21

Alzheimer's disease (AD), the most common form of senile dementia, is characterized by high butyrylcholinesterase (BChE) levels in the brain in later AD stages, for which no treatment is available. Pursuing our studies on selective BChE inhibitors, that may contribute to understand the role of this enzyme in disease progression, we present now microwave-assisted synthesis and anticholinesterase activity of a new nucleoside series embodying 6-chloropurine or 2-acetamido-6-chloropurine linked to D-glucosyl, D-galactosyl and D-mannosyl residues. It was designed to assess the contribution of sugar stereochemistry, purine structure and linkage to the sugar for cholinesterase inhibition efficiency and selectivity. Compounds were subjected to Ellman's assay and their inhibition constants determined. The α-anomers were the most active compounds, while selectivity for BChE or acetylcholinesterase (AChE) inhibition could be tuned by the purine base, by the glycosyl moiety and by N(7)-ligation. Some of the nucleosides were far more potent than the drug galantamine, and the most promising competitive and selective BChE inhibitor, the N(7)-linked 2-acetamido-α-D-mannosylpurine, showed a Ki of 50 nM and a selectivity factor of 340 fold for BChE over AChE.

Design, Synthesis, and Evaluation of New Tripeptides as COX-2 Inhibitors.

PubMed

Vernieri, Ermelinda; Gomez-Monterrey, Isabel; Milite, Ciro; Grieco, Paolo; Musella, Simona; Bertamino, Alessia; Scognamiglio, Ilaria; Alcaro, Stefano; Artese, Anna; Ortuso, Francesco; Novellino, Ettore; Sala, Marina; Campiglia, Pietro

2013-01-01

Cyclooxygenase (COX) is a key enzyme in the biosynthetic pathway leading to the formation of prostaglandins, which are mediators of inflammation. It exists mainly in two isoforms COX-1 and COX-2. The conventional nonsteroidal anti-inflammatory drugs (NSAIDs) have gastrointestinal side effects because they inhibit both isoforms. Recent data demonstrate that the overexpression of these enzymes, and in particular of cyclooxygenases-2, promotes multiple events involved in tumorigenesis; in addition, numerous studies show that the inhibition of cyclooxygenases-2 can delay or prevent certain forms of cancer. Agents that inhibit COX-2 while sparing COX-1 represent a new attractive therapeutic development and offer a new perspective for a further use of COX-2 inhibitors. The present study extends the evaluation of the COX activity to all 20(3) possible natural tripeptide sequences following a rational approach consisting in molecular modeling, synthesis, and biological tests. Based on data obtained from virtual screening, only those peptides with better profile of affinity have been selected and classified into two groups called S and E. Our results suggest that these novel compounds may have potential as structural templates for the design and subsequent development of the new selective COX-2 inhibitors drugs.

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 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%).

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

Wear characterization of nano-hydroxyapatite with addition of titanium (HA-Ti)

NASA Astrophysics Data System (ADS)

Rosmamuhamadani, R.; Arawi, A. Z. O.; Talari, M. K.; Mahat, M. M.; Bonnia, N. N.; Sabrina; Yahaya, M.; Sulaiman, S.; Ismail, M. I. S.

2018-04-01

Hydroxyapatite (Ca10 (PO4)6(OH)2, HA), is an attractive material of an inorganic compound whose chemical composition and crystallographic structures are similar to the composition of the bone. A natural source such as egg shells is composed of 94 wt. % of calcium carbonate (CaCO3), which can be calcined as calcium oxide (CaO) by the calcinations process. The efficient temperature to produce CaO is 900 °C for 2 hours. The synthesis of nano-HA was done by the mixing the diammonium phosphate (DAP) and calcium hydroxide (Ca(OH)2) and subjected into a microwave for 30 minutes at 1100 W irradiation power. Ball milling process was used for 30 minutes to mix the nano-HA with different compositions of titanium. These were pressed to form pallets by hand hydraulic pump (force=2300 psi). The pallets then were sintered at 1200 °C with the heating rate of 3 °C/min for 2 hours. The pallets were tested by several mechanical testing including hardness, compression strength and wear. From the results, HA-25wt. %Ti composite gave the highest hardness, compression and coefficient of friction for wear test values which were 89.6 Hv, 82.5MPa and 0.76μ respectively. It showed that by adding Ti to nano-HA, the mechanical properties of nano-HA could be enhanced. The microstructure analyses by optical micrograph showed that nano-HA-Ti particles displayed shape likes needle morphology. The particles showed the high tendency to form the agglomerations.

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.

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.

Myriocin, a serine palmitoyltransferase inhibitor, increases melanin synthesis in Mel-Ab cells and a skin equivalent model.

PubMed

Li, Hailan; Yun, Hye-Young; Baek, Kwang Jin; Kwon, Nyoun Soo; Park, Kyoung-Chan; Kim, Dong-Seok

2014-03-01

The purpose of this study was to investigate effects of myriocin, an inhibitor of serine palmitoyltransferase, on melanogenesis. It was found that myriocin increased melanin synthesis in a concentration-dependent manner. Moreover, myriocin up-regulated microphthalmia-associated transcription factor (MITF) and tyrosinase expression via phosphorylation of CREB, but it did not directly activate tyrosinase, a rate-limiting melanogenic enzyme. Furthermore, we demonstrated increased melanin synthesis with myriocin on a pigmented skin equivalent model established using Cervi cornus Colla (deer antler glue). One and 5 microM of myriocin darkened the color of the skin equivalent. These results suggest that myriocin may have potential effects for the treatment of hypopigmentary skin diseases like vitiligo or for sunless tanning.

Synthesis and Biological Evaluation of the First Dual Tyrosyl-DNA Phosphodiesterase I (Tdp1) - Topoisomerase I (Top1) Inhibitors

PubMed Central

Nguyen, Trung Xuan; Morrell, Andrew; Conda-Sheridan, Martin; Marchand, Christophe; Agama, Keli; Bermingam, Alun; Stephen, Andrew G.; Chergui, Adel; Naumova, Alena; Fisher, Robert; O’Keefe, Barry R.; Pommier, Yves; Cushman, Mark

2012-01-01

Substances with dual tyrosyl-DNA phosphodiesterase I - topoisomerase I inhibitory activity in one low molecular weight compound would constitute a unique class of anticancer agents that could potentially have significant advantages over drugs that work against the individual enzymes. The present study demonstrates the successful synthesis and evaluation of the first dual Top1-Tdp1 inhibitors, which are based on the indenoisoquinoline chemotype. One bis(indenoisoquinoline) had significant activity against human Tdp1 (IC50 = 1.52 ± 0.05 μM), and it was also equipotent to camptothecin as a Top1 inhibitor. Significant insights into enzyme-drug interactions were gained via structure-activity relationship studies of the series. The present results also document the failure of the previously reported sulfonyl ester pharmacophore to confer Tdp1 inhibition in this indenoisoquinoline class of inhibitors, even though it was demonstrated to work well for the steroid NSC 88915 (7). The current study will facilitate future efforts to optimize dual Top1-Tdp1 inhibitors. PMID:22536944

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.

Mipomersen, an antisense apolipoprotein B synthesis inhibitor.

PubMed

Bell, Damon A; Hooper, Amanda J; Burnett, John R

2011-02-01

mipomersen is a second-generation antisense oligonucleotide (ASO) targeted to human apolipoprotein (apo) B-100, a large protein synthesized by the liver that plays a fundamental role in human lipoprotein metabolism. Mipomersen predominantly distributes to the liver and decreases the production of apoB-100, the primary structural protein of the atherogenic lipoproteins including low density lipoprotein (LDL), thereby reducing plasma LDL-cholesterol and apoB-100 concentrations. the mode of action, preclinical development and clinical trials of mipomersen, an antisense apoB synthesis inhibitor. The paper provides an understanding of the pharmacokinetic and pharmacodynamic characteristics of mipomersen and insight into its clinical efficacy and safety. In clinical trials, mipomersen produced dose-dependent and prolonged reductions in LDL-cholesterol and other apoB-containing lipoproteins, including lipoprotein (a) [Lp(a)] in healthy volunteers and in patients with mild to moderate hypercholesterolemia. Mipomersen has been shown to decrease apoB, LDL-cholesterol and Lp(a) in patients with heterozygous and homozygous familial hypercholesterolemia on maximally tolerated lipid-lowering therapy. mipomersen shows promise as an adjunctive agent by reducing apoB-containing lipoproteins in patients at high risk of atherosclerotic cardiovascular disease who are not at target or are intolerant of statins. Although the short-term efficacy and safety of mipomersen has been established, concern exists regarding the long-term potential for hepatic steatosis with this ASO.

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.

Selectivity of ROCK inhibitors in the spontaneously tonic smooth muscle.

PubMed

Rattan, Satish; Patel, Chirag A

2008-03-01

The selectivity of different Rho kinase (ROCK) inhibitors in the spontaneously tonic smooth muscle has not been investigated. We examined this issue using Y-27632 [(R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarbox anecarboxamide, 2HCl], H-1152 [(S)-(+)-(2-methyl-5-isoquinolinyl) sulfonylhomopiperazine, 2HCl], HA-1077 [(5 isoquinolinesulfonyl) homopiperazine, 2HCl], and ROCK inhibitor II [N-(4-pyridyl)-N'-(2,4,6-trichlorophenyl)urea]. We compared these inhibitors in the spontaneously tonic smooth muscle of the internal anal sphincter (IAS). ROCK, protein kinase C (PKC), and myosin light chain kinase (MLCK) activities were determined in the IAS, before and after different ROCK inhibitors. Y-27632 and H-1152 were approximately 30-fold more potent in the IAS (IC(50): 4.4 x 10(-7) and 7.9 x 10(-8) M, respectively) vs. the phasic rectal smooth muscle (RSM) (IC(50): 1.3 x 10(-5) and 2.5 x 10(-6) M, respectively). HA-1077 and ROCK inhibitor II were equipotent in the IAS vs. RSM. In the IAS, H-1152 was the most potent whereas ROCK inhibitor II is the least. Y-27632 and H-1152 caused concentration-dependent decrease in the IAS tone that correlates directly with the decreases in ROCK activity, without significant effect in the PKC and MLCK activities. This specifically selective correlation between ROCK activity and decrease in the IAS tone was absent in the case of HA-1077 and ROCK inhibitor II, which also inhibited PKC and MLCK. We conclude that the IAS tone is critically dependent on ROCK activity, and H-1152 and Y-27632 are the most selective and potent ROCK inhibitors in the IAS.

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

Structural and biochemical characterization of the protease domain of the mosaic botulinum neurotoxin type HA.

PubMed

Lam, Kwok-Ho; Sikorra, Stefan; Weisemann, Jasmin; Maatsch, Hannah; Perry, Kay; Rummel, Andreas; Binz, Thomas; Jin, Rongsheng

2018-04-23

The extreme toxicity of botulinum neurotoxins (BoNTs) relies on their specific cleavage of SNARE proteins, which eventually leads to muscle paralysis. One newly identified mosaic toxin, BoNT/HA (aka H or FA), cleaves VAMP-2 at a unique position between residues L54 and E55, but the molecular basis underlying VAMP-2-recognition of BoNT/HA remains poorly characterized. Here, we report a ∼2.09 Å resolution crystal structure of the light chain protease domain of BoNT/HA (LC/HA). Structural comparison between LC/HA and LC of BoNT/F1 (LC/F1) reveals distinctive hydrophobic and electrostatic features near the active sites, which may explain their different VAMP-2 cleavage sites. When compared to BoNT/F5 that cleaves VAMP-2 at the same site as BoNT/HA, LC/HA displays higher affinity for VAMP-2, which could be caused by their different surface charge properties surrounding a VAMP-2 exosite-binding cleft. Furthermore, systematic mutagenesis studies on VAMP-2 and structural modeling demonstrate that residues R47 to K59 spanning the cleavage site in VAMP-2 may adopt a novel extended conformation when interacting with LC/HA and LC/F5. Taken together, our structure provides new insights into substrate-recognition of BoNT/HA and paves the way for rational design of small molecule or peptide inhibitors against LC/HA.

I. Development of Metal-Mediated SPOT-Synthesis Methods for the Efficient Construction of Small-Molecule Macroarrays. II. Design and Synthesis of Novel Bacterial Biofilm Inhibitors

NASA Astrophysics Data System (ADS)

Frei, Reto

I. The use of small molecule probes to explore biological phenomena has become a valuable tool in chemical biology. As a result, methods that permit the rapid synthesis and biological evaluation of such compounds are highly sought-after. The small molecule macroarray represents one such approach for the synthesis and identification of novel bioactive agents. Macroarrays are readily constructed via the SPOT-synthesis technique on planar cellulose membranes, yielding spatially addressed libraries of ˜10-1000 unique compounds. We sought to expand the arsenal of chemical reactions compatible with this solid-phase platform, and developed highly efficient SPOT-synthesis protocols for the Mizoroki-Heck, Suzuki-Miyaura, and copper-catalyzed azide-alkyne cycloaddition reaction. We demonstrated that these metal-mediated reactions can be implemented, either individually or sequentially, for the efficient construction of small molecules in high purity on rapid time scales. Utilizing these powerful C-C and C-N bond forming coupling reactions, we constructed a series of macroarrays based on novel stilbene, phenyl-naphthalene, and triazole scaliblds. Subsequent biological testing of the stilbene and phenyl-naphthalene libraries revealed several potent antagonists and agonists, respectively, of the quorum sensing (QS) receptor LuxR in Vibrio fischeri. II. Bacteria living within biofilms are notorious for their resistance to known antibiotic agents, and constitute a major human health threat. Methods to attenuate biofilm growth would have a significant impact on the management of bacterial infections. Despite intense research efforts, small molecules capable of either inhibiting or dispersing biolilms remain scarce. We utilized natural products with purported anti-biofilm or QS inhibitory activity as sources of structural insight to guide the synthesis of novel biofilm modulators with improved activities. These studies revealed 2-aminobenzimidazole derivatives as highly potent

Diels-Alder cycloaddition in the synthesis of 1-azafagomine, analogs, and derivatives as glycosidase inhibitors.

PubMed

Salgueiro, Daniela A L; Sousa, Cristina E A; Fortes, A Gil; Alves, M José

2012-12-01

This comprehensive review deals with the synthesis of 1-azafagomine, analogs, and derivatives having the Diels-Alder cycloaddition as the key step. Most of the compounds referred are racemic or have been resolved by lipase transesterification. There are two asymmetric cycloadditions leading to 1-azafagomine or to an analog. In one case both enantiomers of 1-azafagomine were prepared together with a pair of derivatives. The study comprises glycosidase inhibition studies of the target compounds to a set of glycosidic enzymes, and evidenced molecular features that enhance or diminish their activity as glycosidase inhibitors.

Preparation and characterization of NiW-nHA composite catalyst for hydrocracking

NASA Astrophysics Data System (ADS)

Zhou, Gang; Hou, Yongzhao; Liu, Lei; Liu, Hongru; Liu, Can; Liu, Jing; Qiao, Huiting; Liu, Wenyong; Fan, Yubo; Shen, Shituan; Rong, Long

2012-11-01

The synthesis, characterization and catalytic capability of the NiW-nano-hydroxyapatite (NiW-nHA) composite were investigated in this paper. The NiW-nHA catalyst was prepared by a co-precipitation method. Then Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDX) were used to analyze this material. In addition, the catalytic capacity of the NiW-nHA composite was also examined by FT-IR and gas chromatography (GC). The results of FT-IR analysis indicated that Ni, W and nHA combined closely. TEM observation revealed that this catalyst was needle shaped and the crystal retained a nanometer size. XRD data also suggested that a new phase of CaWO4 appeared and the lattice parameters of nHA changed in this system. nHA was the carrier of metals. The rates of Ni/W-loading were 73.24% and 65.99% according to the EDX data, respectively. Furthermore, the conversion of 91.88% Jatropha oil was achieved at 360 °C and 3 MPa h-1 over NiW-nHA catalyst. The straight chain alkanes ranging from C15 to C18 were the main components in the production. The yield of C15-C18 alkanes was up to 83.56 wt%. The reaction pathway involved hydrocracking of the C&z.dbd;C bonds of these triglycerides from Jatropha oil. This paper developed a novel non-sulfided catalyst to obtain a ``green biofuel'' from vegetable oil.

The angiotensin II type 1 receptor-neprilysin inhibitor LCZ696 blocked aldosterone synthesis in a human adrenocortical cell line.

PubMed

Miura, Shin-Ichiro; Suematsu, Yasunori; Matsuo, Yoshino; Tomita, Sayo; Nakayama, Asuka; Goto, Masaki; Arimura, Tadaaki; Kuwano, Takashi; Yahiro, Eiji; Saku, Keijiro

2016-11-01

A recent clinical study indicated that an angiotensin II (Ang II) type 1 (AT 1 ) receptor-neprilysin inhibitor (ARNi) designated LCZ696 (sacubitril/valsartan, as combined sodium complex) was superior to enalapril at reducing the risks of death and hospitalization due to heart failure. Therefore, we investigated the possible mechanisms of the beneficial effect of LCZ696, in which the inhibition of neprilysin enhances atrial natriuretic peptide (NP) or brain NP (ANP or BNP)-evoked signals that can block Ang II/AT 1 receptor-induced aldosterone (Ald) synthesis in human adrenocortical cells. The binding affinity of valsartan+LBQ657 (active moiety of sacubitril) to the AT 1 receptor was greater than that of valsartan alone in an AT 1 receptor-expressing human embryonic kidney cell-based assay. There was no difference in the dissociation from the AT 1 receptor between valsartan+LBQ657 and valsartan alone. In Ang II-sensitized human adrenocortical cells, ANP or BNP alone, but not LBQ657 or valsartan alone, significantly decreased Ald synthesis. The level of suppression of Ald synthesis by ANP or BNP with LBQ657 was greater than that by ANP or BNP without LBQ657. The suppression of ANP was blocked by inhibitors of regulator of G-protein signaling proteins and cyclic GMP-dependent protein kinase. The inhibition of neprilysin did not change the mRNA levels of the AT 1 receptor, ANP receptor A, regulator of G-protein signaling protein, renin or 3β-hydroxysteroid dehydrogenases. In conclusion, the inhibition of neprilysin by LBQ657 enhances the NP-evoked signals that can block Ang II/AT 1 receptor-induced Ald synthesis in human adrenocortical cells.

Synthesis and Herbicidal Activity of Pyrido[2,3-d]pyrimidine-2,4-dione-Benzoxazinone Hybrids as Protoporphyrinogen Oxidase Inhibitors.

PubMed

Wang, Da-Wei; Li, Qian; Wen, Kai; Ismail, Ismail; Liu, Dan-Dan; Niu, Cong-Wei; Wen, Xin; Yang, Guang-Fu; Xi, Zhen

2017-07-05

To search for new protoporphyrinogen oxidase (PPO, EC 1.3.3.4) inhibitors with improved bioactivity, a series of novel pyrido[2,3-d]pyrimidine-2,4-dione-benzoxazinone hybrids, 9-13, were designed and synthesized. Several compounds with improved tobacco PPO (mtPPO)-inhibiting and promising herbicidal activities were found. Among them, the most potent compound, 3-(7-fluoro-3-oxo-4-(prop-2-yn-1-yl)-3,4-dihydro-2H-benzo[b][1,4] oxazin-6-yl)-1-methylpyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione, 11q, with a K i value of 0.0074 μM, showed six times more activity than flumioxazin (K i = 0.046 μM) against mtPPO. Compound 11q displayed a strong and broad spectrum of weed control at 37.5-150 g of active ingredient (ai)/ha by both post- and pre-emergence application, which was comparable to that of flumioxazin. 11q was safe to maize, soybean, peanut, and cotton at 150 g ai/ha, and selective to rice and wheat at 75 g ai/ha by pre-emergence application, indicating potential applicability in these fields.

Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis.

PubMed

Yang, Jung-Bo; Quan, Juan-Hua; Kim, Ye-Eun; Rhee, Yun-Ee; Kang, Byung-Hyun; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

2015-08-01

Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

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

PubMed

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

2015-10-05

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

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.

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

PubMed

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

2015-06-08

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

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

NASA Astrophysics Data System (ADS)

Adhikari, Arijit A.

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

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

PubMed

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

2018-05-24

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

A close insight to factor VIII inhibitor in the congenital hemophilia A.

PubMed

Tabriznia-Tabrizi, Shamsoreza; Gholampour, Marzie; Mansouritorghabeh, Hassan

2016-09-01

Hemophilia A (HA) has an X-linked pattern of inheritance and is the most common of the hemorrhagic disorders. HA is caused by a decreased or deficiency of the functional clotting factor VIII (FVIII) and effects 1 in 5000-10,000 male births. The common treatment for hemophilia is replacement therapy by plasma-derived or recombinant FVIII. Approximately 20-30% of people with a severe type of HA develop an inhibitor and this phenomenon is the main challenge in the management of these patients. Genetic factors and environmental determinants contribute to inhibitor development. Here, the roles of various genetic and environmental factors such as the type of FVIII concentrate used, the number of exposure days, and peak treatment time will be discussed in detail. It seems this information is helpful for hematologists. A literature review was done in January 2016 on PubMed and Scopus using the following keywords:' h(a)emophilia A & factor VIII inhibitor', 'h(a)emophilia A & factor VIII alloantibody', 'h(a)emophilia A & inhibitor'. There was no time limitation; however, there was an English language limitation placed on the articles selected. Expert commentary: Influential genetic and environmental factors in developing inhibitors have been discussed. Most of the risk factors are related to previously untreated patients with hemophili.

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

PubMed

Berti, Federico; Frecer, Vladimir; Miertus, Stanislav

2014-01-01

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

Green synthesis of nanosilver particles by Aspergillus terreus HA1N and Penicillium expansum HA2N and its antifungal activity against mycotoxigenic fungi.

PubMed

Ammar, H A M; El-Desouky, T A

2016-07-01

The aim of this study was to synthesize silver nanoparticles (AgNPs) by an eco-friendly and low-cost method using the fungi Aspergillus terreus HA1N and Penicillium expansum HA2N as an alternative to chemical procedures mostly requiring drastic experimental conditions emitting toxic chemical byproducts. Also, this study has been extended to evaluate the effect of AgNPs on the growth of some mycotoxigenic fungi and ochratoxin A (OTA) produced by Aspergillus ochraceus. The AgNPs have been characterized by UV-Visible Spectrophotometer, Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscope (TEM). The TEM analysis has revealed that the size of AgNPs ranged between 14 and 25 nm in the case of P. expansum and 10-18 nm in the case of A. terreus. The antifungal activity of AgNP colloids has indicated that the highest inhibition zone was detected with AgNPs synthesized by A. terreus HA1N against all tested fungi. The highest inhibition zone was detected with Aspergillus niger at concentrations 3 and 6 μg of AgNP solution (7·56 ± 0·38 and 11·3 ± 1·8 mm, respectively) while, A. ochraceus showed the maximum inhibition zone (16·33 ± 0·96 mm) at the concentration 9 μg of AgNPs synthesized by A. terreus. The results have also indicated that the AgNPs synthesized by A. terreus and P. expansum at the concentration 220 μg/100 ml media gave the highest reduction of OTA, where the percentages of reduction were 58·87 and 52·18% respectively. The smallest size AgNPs synthesized by A. terreus HA1N are better in their antifungal activity against all tested mycotoxigenic fungi than the largest one synthesized by P. expansum HA2N. This is the first study focused on using AgNPs in control of OTA production. © 2016 The Society for Applied Microbiology.

Reversible Association of the Hemagglutinin Subcomplex, HA-33/HA-17 Trimer, with the Botulinum Toxin Complex.

PubMed

Sagane, Yoshimasa; Mutoh, Shingo; Koizumi, Ryosuke; Suzuki, Tomonori; Miyashita, Shin-Ichiro; Miyata, Keita; Ohyama, Tohru; Niwa, Koichi; Watanabe, Toshihiro

2017-10-01

Botulinum neurotoxin (BoNT) associates with nontoxic proteins, either a nontoxic nonhemagglutinin (NTNHA) or the complex of NTNHA and hemagglutinin (HA), to form M- or L-toxin complexes (TCs). Single BoNT and NTNHA molecules are associated and form M-TC. A trimer of the 70-kDa HA protein (HA-70) attaches to the M-TC to form M-TC/HA-70. Further, 1-3 arm-like 33- and 17-kDa HA molecules (HA-33/HA-17 trimer), consisting of 1 HA-17 protein and 2 HA-33 proteins, can attach to the M-TC/HA-70 complex, yielding 1-, 2-, and 3-arm L-TC. In this study, the purified 1- and 2-arm L-TCs spontaneously converted into another L-TC species after acquiring the HA-33/HA-17 trimer from other TCs during long-term storage and freezing/thawing. Transmission electron microscopy analysis provided evidence of the formation of detached HA-33/HA-17 trimers in the purified TC preparation. These findings provide evidence of reversible association/dissociation of the M-TC/HA-70 complex with the HA-33/HA-17 trimers, as well as dynamic conversion of the quaternary structure of botulinum TC in culture.

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.

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.

Inhibition of influenza virus infection and hemagglutinin cleavage by the protease inhibitor HAI-2

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

Hamilton, Brian S.; Chung, Changik; Cyphers, Soreen Y.

Highlights: • Biochemical and cell biological analysis of HAI-2 as an inhibitor of influenza HA cleavage activation. • Biochemical and cell biological analysis of HAI-2 as an inhibitor of influenza virus infection. • Comparative analysis of HAI-2 for vesicular stomatitis virus and human parainfluenza virus type-1. • Analysis of the activity of HAI-2 in a mouse model of influenza. - Abstract: Influenza virus remains a significant concern to public health, with the continued potential for a high fatality pandemic. Vaccination and antiviral therapeutics are effective measures to circumvent influenza virus infection, however, multiple strains have emerged that are resistant tomore » the antiviral therapeutics currently on the market. With this considered, investigation of alternative antiviral therapeutics is being conducted. One such approach is to inhibit cleavage activation of the influenza virus hemagglutinin (HA), which is an essential step in the viral replication cycle that permits viral-endosome fusion. Therefore, targeting trypsin-like, host proteases responsible for HA cleavage in vivo may prove to be an effective therapeutic. Hepatocyte growth factor activator inhibitor 2 (HAI-2) is naturally expressed in the respiratory tract and is a potent inhibitor of trypsin-like serine proteases, some of which have been determined to cleave HA. In this study, we demonstrate that HAI-2 is an effective inhibitor of cleavage of HA from the human-adapted H1 and H3 subtypes. HAI-2 inhibited influenza virus H1N1 infection in cell culture, and HAI-2 administration showed protection in a mouse model of influenza. HAI-2 has the potential to be an effective, alternative antiviral therapeutic for influenza.« less

Phenotypic Drug Susceptibility Assay for Influenza Virus Neuraminidase Inhibitors

PubMed Central

McSharry, James J.; McDonough, Ann C.; Olson, Betty A.; Drusano, George L.

2004-01-01

A flow cytometric (fluorescence-activated cell sorter [FACS]) assay was developed for analysis of the drug susceptibilities of wild-type and drug-resistant influenza A and B virus laboratory strains and clinical isolates for the neuraminidase (NA) inhibitors oseltamivir carboxylate, zanamivir, and peramivir. The drug susceptibilities of wild-type influenza viruses and those with mutations in the hemagglutinin (HA) and/or NA genes rendering them resistant to one or more of the NA inhibitors were easily determined with the FACS assay. The drug concentrations that reduced the number of virus-infected cells or the number of PFU by 50% as determined by the FACS assay were similar to those obtained with the more time-consuming and labor-intensive virus yield reduction assay. The NA inhibition (NAI) assay confirmed the resistance patterns demonstrated by the FACS and virus yield assays for drug-resistant influenza viruses with mutations in the NA gene. However, only the FACS and virus yield assays detected NA inhibitor-resistant influenza viruses with mutations in the HA gene but not in the NA gene. The FACS assay is more rapid and less labor-intensive than the virus yield assay and just as quantitative. The FACS assay determines the drug susceptibilities of influenza viruses with mutations in either the HA or NA genes, making the assay more broadly useful than the NAI assay for measuring the in vitro susceptibilities of influenza viruses for NA inhibitors. However, since only viruses with mutations in the NA gene that lead to resistance to the NA inhibitors correlate with clinical resistance, this in vitro assay should not be used in the clinical setting to determine resistance to NA inhibitors. The assay may be useful for determining the in vivo susceptibilities of other compounds effective against influenza A and B viruses. PMID:14715540

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.

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.

Hydroxyapatite Fibers: A Review of Synthesis Methods

NASA Astrophysics Data System (ADS)

Qi, Mei-Li; He, Kun; Huang, Zhen-Nan; Shahbazian-Yassar, Reza; Xiao, Gui-Yong; Lu, Yu-Peng; Shokuhfar, Tolou

2017-08-01

Hydroxyapatite (HA) exhibits excellent biocompatibility, bioactivity, osteoconductivity, non-toxicity and so on, making it a perfect candidate for biomedical applications. However, HA is not qualified to be used in load-bearing sites due to its poor flexural strength and fracture toughness. Design, synthesis and application of fibrous HA is a promising strategy to overcome the inherent brittleness. This review provides a brief description of HA and hydroxyapatite fiber (HAF), then introduces different synthesis methods of HAF and highlights the inherent merits and drawbacks involved in each method. Finally, the future perspectives in this active research area are given. The purpose of this review is to acquaint the reader with this promising new field of biomaterials research and with emphasis on recent techniques to obtain continuous, uniform and long HAF.

Combination of hemostatic therapies for treatment of patients with hemophilia A and inhibitors.

PubMed

Livnat, Tami; Budnik, Ivan; Levy-Mendelovich, Sarina; Avishai, Einat; Misgav, Mudi; Barg, Assaf Arie; Lubetsky, Aharon; Brutman-Barazani, Tami; Kenet, Gili

2017-07-01

Therapy application and monitoring of patients with hemophilia A (HA) and inhibitors are challenging. In the current study, combined FVIII - bypass therapy was implemented for a cohort of severe HA patients with inhibitors. Plasma of 15 HA patients with inhibitors was spiked ex vivo with FVIII, rFVIIa, FEIBA and their combinations and thrombin generation (TG) was studied. Some patients who experienced hemarthroses or required minor surgeries were treated by a combined concomitant administration of FVIII+FEIBA as IV bolus doses. TG spiking studies showed individual responses not correlated to inhibitor titer. Combinations of agents augmented TG as compared to any single agent, while combined FVIII+FEIBA yielded the highest TG, supporting it as a potential treatment. Following emergent successful surgery of child treated by concomitant FVIII+FEIBA, a total of 396 episodes in 7/15 patients were treated with concomitant FVIII+FEIBA. Five patients were treated for bleeding episodes only, whereas 2 were children undergoing immune tolerance induction (ITI) with FEIBA prophylaxis. Four minor surgeries were performed on FVIII+FEIBA repeated infusions. Neither thrombosis nor any other adverse events were documented. A combination of FVIII+FEIBA may be effective and safe as an alternative treatment option for some high-responding inhibitor patients. Copyright © 2017 Elsevier Inc. All rights reserved.

In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti-proliferative properties against HeLa cell line.

PubMed

Srivastava, Pallavee; Braganca, Judith M; Kowshik, Meenal

2014-01-01

Nanoparticles synthesis by bacteria and yeasts has been widely reported, however, synthesis using halophilic archaea is still in a nascent stage. This study aimed at the intracellular synthesis of selenium nanoparticles (SeNPs) by the haloarchaeon Halococcus salifodinae BK18 when grown in the presence of sodium selenite. Crystallographic characterization of SeNPs by X-ray diffraction, Selected area electron diffraction, and transmission electron microscopy exhibited rod shaped nanoparticles with hexagonal crystal lattice, a crystallite domain size of 28 nm and an aspect ratio (length:diameter) of 13:1. Energy disruptive analysis of X-ray analysis confirmed the presence of selenium in the nano-preparation. The nitrate reductase enzyme assay and the inhibitor studies indicated the involvement of NADH-dependent nitrate reductase in SeNPs synthesis and metal tolerance. The SeNPs exhibited good anti-proliferative properties against HeLa cell lines while being non-cytotoxic to normal cell line model HaCat, suggesting the use of these SeNPs as cancer chemotherapeutic agent. This is the first study on selenium nanoparticles synthesis by haloarchaea. © 2014 American Institute of Chemical Engineers.

Inhibitors of Fatty Acid Synthesis Induce PPARα-Regulated Fatty Acid β-Oxidative Genes: Synergistic Roles of L-FABP and Glucose

PubMed Central

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

2013-01-01

While TOFA (acetyl CoA carboxylase inhibitor) and C75 (fatty acid synthase inhibitor) prevent lipid accumulation by inhibiting fatty acid synthesis, the mechanism of action is not simply accounted for by inhibition of the enzymes alone. Liver fatty acid binding protein (L-FABP), a mediator of long chain fatty acid signaling to peroxisome proliferator-activated receptor-α (PPARα) in the nucleus, was found to bind TOFA and its activated CoA thioester, TOFyl-CoA, with high affinity while binding C75 and C75-CoA with lower affinity. Binding of TOFA and C75-CoA significantly altered L-FABP secondary structure. High (20 mM) but not physiological (6 mM) glucose conferred on both TOFA and C75 the ability to induce PPARα transcription of the fatty acid β-oxidative enzymes CPT1A, CPT2, and ACOX1 in cultured primary hepatocytes from wild-type (WT) mice. However, L-FABP gene ablation abolished the effects of TOFA and C75 in the context of high glucose. These effects were not associated with an increased cellular level of unesterified fatty acids but rather by increased intracellular glucose. These findings suggested that L-FABP may function as an intracellular fatty acid synthesis inhibitor binding protein facilitating TOFA and C75-mediated induction of PPARα in the context of high glucose at levels similar to those in uncontrolled diabetes. PMID:23533380

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.

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

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

Riganti, Chiara; Costamagna, Costanzo; Doublier, Sophie

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

Down-regulation of UDP-glucose dehydrogenase affects glycosaminoglycans synthesis and motility in HCT-8 colorectal carcinoma cells

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

Wang, Tsung-Pao; Pan, Yun-Ru; Fu, Chien-Yu

2010-10-15

UDP-glucose dehydrogenase (UGDH) catalyzes oxidation of UDP-glucose to yield UDP-glucuronic acid, a precursor of hyaluronic acid (HA) and other glycosaminoglycans (GAGs) in extracellular matrix. Although association of extracellular matrix with cell proliferation and migration has been well documented, the importance of UGDH in these behaviors is not clear. Using UGDH-specific small interference RNA to treat HCT-8 colorectal carcinoma cells, a decrease in both mRNA and protein levels of UGDH, as well as the cellular UDP-glucuronic acid and GAG production was observed. Treatment of HCT-8 cells with either UGDH-specific siRNA or HA synthesis inhibitor 4-methylumbelliferone effectively delayed cell aggregation into multicellularmore » spheroids and impaired cell motility in both three-dimensional collagen gel and transwell migration assays. The reduction in cell aggregation and migration rates could be restored by addition of exogenous HA. These results indicate that UGDH can regulate cell motility through the production of GAG. The enzyme may be a potential target for therapeutic intervention of colorectal cancers.« less

Facile dimethyl amino group triggered cyclic sulfonamides synthesis and evaluation as alkaline phosphatase inhibitors.

PubMed

Bhatti, Huma Aslam; Khatoon, Memoona; Al-Rashida, Mariya; Bano, Huma; Iqbal, Nafees; Zaib-Un-Nisa; Yousuf, Sammer; Khan, Khalid Mohammed; Hameed, Abdul; Iqbal, Jamshed

2017-04-01

Owing to the biological importance of cyclic sulfonamides (sultams), herein we report a new, facile and cost-effective method for the synthesis of sultams that makes use of a reaction between dansyl amide and easily accessible benzaldehydes under mildly acidic conditions. All compounds were obtained in good yields (69-96%). Consequently a series of cyclic sulfonamides (7a-7n) was synthesized and characterized using FTIR, MS and NMR spectroscopy, crystal structure of compound 7b has also been determined. All compounds were evaluated for their potential to inhibit alkaline phosphatase (bTNAP and bIAP). All compounds were found to be excellent inhibitors of bTNAP with IC 50 values in lower micro-molar range (0.11-6.63μM). Most of the compounds were selective inhibitors of bTNAP over bIAP. Only six compounds were found to be active against bIAP (IC 50 values in the range 0.38-3.48μM). Molecular docking studies were carried out to identify and rationalize the structural elements necessary for efficient AP inhibition. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

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

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.

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.

New MKLP-2 inhibitors in the paprotrain series: Design, synthesis and biological evaluations.

PubMed

Labrière, Christophe; Talapatra, Sandeep K; Thoret, Sylviane; Bougeret, Cécile; Kozielski, Frank; Guillou, Catherine

2016-02-15

Members of the kinesin superfamily are involved in key functions during intracellular transport and cell division. Their involvement in cell division makes certain kinesins potential targets for drug development in cancer chemotherapy. The two most advanced kinesin targets are Eg5 and CENP-E with inhibitors in clinical trials. Other mitotic kinesins are also being investigated for their potential as prospective drug targets. One recently identified novel potential cancer therapeutic target is the Mitotic kinesin-like protein 2 (MKLP-2), a member of the kinesin-6 family, which plays an essential role during cytokinesis. Previous studies have shown that inhibition of MKLP-2 leads to binucleated cells due to failure of cytokinesis. We have previously identified compound 1 (paprotrain) as the first selective inhibitor of MKLP-2. Herein we describe the synthesis and biological evaluation of new analogs of 1. Our structure-activity relationship (SAR) study reveals the key chemical elements in the paprotrain family necessary for MKLP-2 inhibition. We have successfully identified one MKLP-2 inhibitor 9a that is more potent than paprotrain. In addition, in vitro analysis of a panel of kinesins revealed that this compound is selective for MKLP-2 compared to other kinesins tested and also does not have an effect on microtubule dynamics. Upon testing in different cancer cell lines, we find that the more potent paprotrain analog is also more active than paprotrain in 10 different cancer cell lines. Increased selectivity and higher potency is therefore a step forward toward establishing MKLP-2 as a potential cancer drug target. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sugar-induced conformational change found in the HA-33/HA-17 trimer of the botulinum toxin complex.

PubMed

Sagane, Yoshimasa; Hayashi, Shintaro; Matsumoto, Takashi; Miyashita, Shin-Ichiro; Inui, Ken; Miyata, Keita; Yajima, Shunsuke; Suzuki, Tomonori; Hasegawa, Kimiko; Yamano, Akihito; Nishikawa, Atsushi; Ohyama, Tohru; Watanabe, Toshihiro; Niwa, Koichi

2013-08-30

Large-sized botulinum toxin complex (L-TC) is formed by conjugation of neurotoxin, nontoxic nonhemagglutinin and hemagglutinin (HA) complex. The HA complex is formed by association of three HA-70 molecules and three HA-33/HA-17 trimers, comprised of a single HA-17 and two HA-33 proteins. The HA-33/HA-17 trimer isolated from serotype D L-TC has the ability to bind to and penetrate through the intestinal epithelial cell monolayer in a sialic acid-dependent manner, and thus it plays an important role in toxin delivery through the intestinal cell wall. In this study, we determined the solution structure of the HA-33/HA-17 trimer by using small-angle X-ray scattering (SAXS). The SAXS image of HA-33/HA-17 exhibited broadly similar appearance to the crystal image of the complex. On the other hand, in the presence of N-acetylneuraminic acid, glucose and galactose, the solution structure of the HA-33/HA-17 trimer was drastically altered compared to the structure in the absence of the sugars. Sugar-induced structural change of the HA-33/HA-17 trimer may contribute to cell binding and subsequent transport across the intestinal cell layer. Copyright © 2013 Elsevier Inc. All rights reserved.

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.

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

Effects of inhibitors on early protein, RNA, and lipid synthesis in germinating vesicular-arbuscular mycorrhizal fungal spores of Glomus caledonium.

PubMed

Beilby, J P

1983-05-01

The incorporation of isotopically labelled precursors, [1-14C]leucine, [2-14C]uracil and [1-14C]acetate, by germinating spores of the vesicular-arbuscular mycorrhizal fungus Glomus caledonium was investigated after prior incubation with several metabolic inhibitors. Inhibition of isotope incorporation was greatest with ethidium bromide and cycloheximide and least with chloramphenicol and actinomycin D. The incorporation of [1-14C]leucine into protein was reduced by 92% within 60 min of incubation in either ethidium bromide at 5 micrograms/mL or cycloheximide at 100 micrograms/mL. For these studies time zero was coincident with dry quiescent spores being first wet. Lipid synthesis during germination of the spores was detected at 120 min by following the incorporation of [1-14C]acetate. At 51 h, incorporation was greater in the triacylglycerides and diacylglycerides than in the free sterols, phospholipids, or free fatty acid. Spores exposed to cycloheximide for 60 min after imbibition showed very little phospholipid synthesis and no free fatty acid synthesis. The synthesis of RNA after spore imbibition is also discussed.

Generating a Generation of Proteasome Inhibitors: From Microbial Fermentation to Total Synthesis of Salinosporamide A (Marizomib) and Other Salinosporamides

PubMed Central

Potts, Barbara C.; Lam, Kin S.

2010-01-01

The salinosporamides are potent proteasome inhibitors among which the parent marine-derived natural product salinosporamide A (marizomib; NPI-0052; 1) is currently in clinical trials for the treatment of various cancers. Methods to generate this class of compounds include fermentation and natural products chemistry, precursor-directed biosynthesis, mutasynthesis, semi-synthesis, and total synthesis. The end products range from biochemical tools for probing mechanism of action to clinical trials materials; in turn, the considerable efforts to produce the target molecules have expanded the technologies used to generate them. Here, the full complement of methods is reviewed, reflecting remarkable contributions from scientists of various disciplines over a period of 7 years since the first publication of the structure of 1. PMID:20479958

Design and synthesis of aminocoumarin derivatives as DPP-IV inhibitors and anticancer agents.

PubMed

Soni, Rina; Soman, Shubhangi S

2018-09-01

DPP-IV "a moonlighting protein" has immerged as promising pathway to control Type 2 diabetes as well as found to play key role in earlier stages of cancer. Here we have reported design, synthesis and applications of aminocoumarin derivatives as DPP-IV inhibitors. Compounds have been synthesized and studied for their DPP-IV inhibition activity. Three compounds have shown moderate inhibition at 100 µM concentration. All compounds were also screened for their anticancer activity against A549 (Lung cancer cell line), MCF-7 (Breast cancer cell line) using MTT assay. One of the compounds has shown very good anticancer activity with IC 50 value 24 ± 0.1 nM against A549 cell line. Copyright © 2018 Elsevier Inc. 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

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

Identification of a broad-spectrum inhibitor of virus RNA synthesis: validation of a prototype virus-based approach

PubMed Central

Filone, Claire Marie; Hodges, Erin N.; Honeyman, Brian; Bushkin, G. Guy; Boyd, Karla; Platt, Andrew; Ni, Feng; Strom, Kyle; Hensley, Lisa; Snyder, John K.; Connor, John H.

2013-01-01

There are no approved therapeutics for the most deadly nonsegmented negative-strand (NNS) RNA viruses, including Ebola (EBOV). To identify new chemical scaffolds for development of broad-spectrum antivirals, we undertook a prototype-based lead identification screen. Using the prototype NNS virus, vesicular stomatitis virus (VSV), multiple inhibitory compounds were identified. Three compounds were investigated for broad-spectrum activity, and inhibited EBOV infection. The most potent, CMLDBU3402, was selected for further study. CMLDBU3402 did not show significant activity against segmented negative-strand RNA viruses suggesting proscribed broad-spectrum activity. Mechanistic analysis indicated that CMLDBU3402 blocked VSV viral RNA synthesis and inhibited EBOV RNA transcription, demonstrating a consistent mechanism of action against genetically distinct viruses. The identification of this chemical backbone as a broad-spectrum inhibitor of viral RNA synthesis offers significant potential for the development of new therapies for highly pathogenic viruses. PMID:23521799

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

PubMed

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

2011-06-01

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

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

PubMed

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

2001-02-09

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

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.

Conformational divergence in the HA-33/HA-17 trimer of serotype C and D botulinum toxin complex.

PubMed

Sagane, Yoshimasa; Hayashi, Shintaro; Akiyama, Tomonori; Matsumoto, Takashi; Hasegawa, Kimiko; Yamano, Akihito; Suzuki, Tomonori; Niwa, Koichi; Watanabe, Toshihiro; Yajima, Shunsuke

2016-08-05

Clostridium botulinum produces a large toxin complex (L-TC) comprising botulinum neurotoxin associated with auxiliary nontoxic proteins. A complex of 33- and 17-kDa hemagglutinins (an HA-33/HA-17 trimer) enhances L-TC transport across the intestinal epithelial cell layer via binding HA-33 to a sugar on the cell surface. At least two subtypes of serotype C/D HA-33 exhibit differing preferences for the sugars sialic acid and galactose. Here, we compared the three-dimensional structures of the galactose-binding HA-33 and HA-33/HA-17 trimers produced by the C-Yoichi strain. Comparisons of serotype C/D HA-33 sequences reveal a variable region with relatively low sequence similarity across the C. botulinum strains; the variability of this region may influence the manner of sugar-recognition by HA-33. Crystal structures of sialic acid- and galactose-binding HA-33 are broadly similar in appearance. However, small-angle X-ray scattering revealed distinct solution structures for HA-33/HA-17 trimers. A structural change in the C-terminal variable region of HA-33 might cause a dramatic shift in the conformation and sugar-recognition mode of HA-33/HA-17 trimer. Copyright © 2016 Elsevier Inc. All rights reserved.

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

PubMed

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

2013-01-01

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

Effect of inhibitors of prostaglandin synthesis on gonadotropin release in the rat.

PubMed

Ojeda, S R; Harms, P G; McCann, S M

1975-10-01

To study the effect of blockade of prostaglandin (PG) synthesis on gonadotropin release in the rat, inhibitors of PG synthesis were injected by various routes in various experimental conditions. The injection of 5-, 8-, 11-, 14-eicosatetraynoic acid (TYA) into the third ventricle (3rd V) significantly decreased plasma LH of ovariectomized (OVX) rats 1, 2, and 4 h following its injection; however, TYA failed to alter plasma LH in OVX rats when administered as a single sc injection and also failed to prevent the post-castration rise in plasma LH when administered sc once daily for 4 days to short-term OVX rats. None of these treatments altered plasma FSH concentrations. Indomethacin (Id) injected into the 3rd V or implanted into the medial basal hypothalamus (MBH) of OVX rats depressed plasma LH 1--6 h later. This effect was no longer observed 24--72 h following its implantation in the MBH. When different doses of Id were administered as single sc injections to OVX rats, plasma LH titers were depressed 24--32 h later, whereas plasma FSH remained either unaltered or was slightly increased. Similarly, the post-castration rise of plasma LH but not that of FSH in male rats was suppressed by a single sc injection of Id given 6 h before orchidectomy. Id administered acutely iv failed to modify the pulsatile release of LH in OVX rats, but it effectively inhibited this release when injected sc 20--30 h before the initiation of blood collection. Moreover, Id blocked the progesterone-induced LH and FSH release in OVX estrogen-primed rats when given sc 24 h before progesterone, but not when it was injected either sc or iv shortly (2 h) before or shortly after (1--3 h) progesterone treatment. Rats treated with Id showed a decrease in BW 24--32 h afters its sc injection. However, the effects of Id on LH release could not be explained by lack of food intake since fasted controls showed LH titers similar to fed rats. Id did not significantly inhibit the LH release in response to

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.

Combining Urease and Nitrification Inhibitors with Incorporation Reduces Ammonia and Nitrous Oxide Emissions and Increases Corn Yields.

PubMed

Drury, Craig F; Yang, Xueming; Reynolds, W Dan; Calder, Wayne; Oloya, Tom O; Woodley, Alex L

2017-09-01

Less than 50% of applied nitrogen (N) fertilizer is typically recovered by corn ( L.) due to climatic constraints, soil degradation, overapplication, and losses to air and water. Two application methods, two N sources, and two inhibitors were evaluated to reduce N losses and enhance crop uptake. The treatments included broadcast urea (BrUrea), BrUrea with a urease inhibitor (BrUrea+UI), BrUrea with a urease and a nitrification inhibitor (BrUrea+UI+NI), injection of urea ammonium nitrate (InjUAN), and injected with one or both inhibitors (InjUAN+UI, InjUAN+UI+NI), and a control. The BrUrea treatment lost 50% (64.4 kg N ha) of the applied N due to ammonia volatilization, but losses were reduced by 64% with BrUrea+UI+NI (23.0 kg N ha) and by 60% with InjUAN (26.1 kg N ha). Ammonia losses were lower and crop yields were greater in 2014 than 2013 as a result of the more favorable weather when N was applied in 2014. When ammonia volatilization was reduced by adding a urease inhibitor, NO emissions were increased by 30 to 31% with BrUrea+UI and InjUAN+UI compared with BrUrea and InjUAN, respectively. Pollution swapping was avoided when both inhibitors were used (BrUrea+UI+NI, InjUAN+UI+NI) as both ammonia volatilization and NO emissions were reduced, and corn grain yields increased by 5% with BrUrea+UI+NI and by 7% with InjUAN+UI+NI compared with BrUrea and InjUAN, respectively. The combination of two N management strategies (InjUAN+UI+NI) increased yields by 19% (12.9 t ha) compared with BrUrea (10.8 t ha). Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

PubMed

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

1996-09-01

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

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.

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 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.

Synthesis and Pharmacokinetic Evaluation of Siderophore Biosynthesis Inhibitors for Mycobacterium tuberculosis

PubMed Central

Nelson, Kathryn M.; Viswanathan, Kishore; Dawadi, Surendra; Duckworth, Benjamin P.; Boshoff, Helena I.; Barry, Clifton E.; Aldrich, Courtney C.

2015-01-01

MbtA catalyzes the first committed biosynthetic step of the mycobactins, which are important virulence factors associated with iron acquisition in Mycobacterium tuberculosis. MbtA is a validated therapeutic target for antitubercular drug development. 5′-O-[N-(salicyl)sulfamoyl]adenosine (1) is a bisubstrate inhibitor of MbtA and exhibits exceptionally potent biochemical and antitubercular activity. However, 1 suffers from sub-optimal drug disposition properties resulting in a short half-life (t1/2), low exposure (AUC), and low bioavailability (F). Four strategies were pursued to address these liabilities including the synthesis of prodrugs, increasing the pKa of the acyl-sulfonyl moiety, modulation of the lipophilicity, and strategic introduction of fluorine into 1. Complete pharmacokinetic (PK) analysis of all compounds was performed. The most successful modifications involved fluorination of the nucleoside that provided substantial improvements in t1/2 and AUC. Increasing the pKa of the acyl-sulfonyl linker yielded incremental enhancements while modulation of the lipophilicity and prodrug approaches led to substantially poorer PK parameters. PMID:26110337

Synthesis and Biological Evaluation of Macrocyclized Betulin Derivatives as a Novel Class of Anti-HIV-1 Maturation Inhibitors.

PubMed

Tang, Jun; Jones, Stacey A; Jeffery, Jerry L; Miranda, Sonia R; Galardi, Cristin M; Irlbeck, David M; Brown, Kevin W; McDanal, Charlene B; Han, Nianhe; Gao, Daxin; Wu, Yongyong; Shen, Bin; Liu, Chunyu; Xi, Caiming; Yang, Heping; Li, Rui; Yu, Yajun; Sun, Yufei; Jin, Zhimin; Wang, Erjuan; Johns, Brian A

2014-01-01

A macrocycle provides diverse functionality and stereochemical complexity in a conformationally preorganized ring structure, and it occupies a unique chemical space in drug discovery. However, the synthetic challenge to access this structural class is high and hinders the exploration of macrocycles. In this study, efficient synthetic routes to macrocyclized betulin derivatives have been established. The macrocycle containing compounds showed equal potency compared to bevirimat in multiple HIV-1 antiviral assays. The synthesis and biological evaluation of this novel series of HIV-1 maturation inhibitors will be discussed.

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.

Synthesis and evaluation of carbocyanine dyes as PRMT inhibitors and imaging agents.

PubMed

Sinha, Sarmistha Halder; Owens, Eric A; Feng, You; Yang, Yutao; Xie, Yan; Tu, Yaping; Henary, Maged; Zheng, Yujun George

2012-08-01

Protein arginine methylation regulates multiple biological processes. Deregulation of protein arginine methyltransferase (PRMT) activities has been observed in many disease phenotypes. Small molecule probes that target PRMTs with strong affinity and selectivity can be used as valuable tools to dissect biological mechanisms of arginine methylation and establish the role of PRMT proteins in a disease process. In this work, we report synthesis and evaluation of a class of carbocyanine compounds containing indolium, benz[e]indolium or benz[c,d]indolium heterocyclic moieties that bind to the predominant arginine methyltransferase PRMT1 and inhibit its methyltransferase activity at low micromolar potencies. In particular, the developed molecules have long wavelength colorimetric and fluorometric photoactivities, which can be used for optical and near-infrared fluorescence imaging in cells or biological tissues. Together, these new chemical probes have potential application in PRMT studies both as enzyme inhibitors and as fluorescent dyes for microscope imaging. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

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.

Inside HDAC with HDAC inhibitors.

PubMed

Bertrand, Philippe

2010-06-01

Histone deacetylase inhibitors are a large group of diverse molecules intrinsically able to inhibit cell proliferation in various cancer cell lines. Their apoptotic effects have been linked to the modulation in the expression of several regulatory tumor suppressor genes caused by the modified status of histone acetylation, a key event in chromatin remodelling. As the initial histone deacetylase activity of HDAC has been extended to other proteins, the possible other biological mechanisms modified by HDAC inhibitor treatments are still to be clarified. The need for HDAC isoform selective inhibitors is an important issue to serve this goal. This review discusses the approaches proposed by several research groups working on the synthesis of HDAC inhibitors, based on modelling studies and the way these findings were used to obtain new HDAC inhibitors with possible isoform selectivity. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Influence of temperature and aging time on HA synthesized by the hydrothermal method.

PubMed

Kothapalli, C R; Wei, M; Legeros, R Z; Shaw, M T

2005-05-01

The influence of temperature and aging time on the morphology and mechanical properties of nano-sized hydroxyapatite (HA) synthesized by a hydrothermal method is reported here. The pre-mixed reactants were poured into a stirred autoclave and reacted at temperatures between 25-250 degrees C for 2-10 h. HA powders thus obtained were examined using X-ray diffraction (XRD), high-resolution field emission scanning electron microscopy (FESEM) and a particle size analyzer. It was found that the aspect ratio of the particles increased with the reaction temperature. The length of the HA particles increased with the reaction temperature below 170 degrees C, but it decreased when the temperature was raised above 170 degrees C. The agglomerates of HA particles were formed during synthesis, and their sizes were strongly dependent on reaction temperatures. As the reaction temperature increased, the agglomerate size decreased (p = 0.008). The density of the discs pressed from these samples reached 85-90% of the theoretical density after sintering at 1200 degrees C for 1 h. No decomposition to other calcium phosphates was detected at this sintering temperature. A correlation existed (p = 0.05) between the agglomerate sizes of HA particles synthesized at various conditions and their sintered densities. With the increase of the agglomerate size, the sintered density of the HA compact decreased. It was found that both the sintered density and flexural strength increased with increasing aging time and reaction temperature. A maximum flexural strength of 78 MPa was observed for the samples synthesized at 170 degrees C for 5 h with the predicted average at these conditions being 65 MPa. These samples attained an average sintered density of 88%.

Optimizing heterosurface adsorbent synthesis for liquid chromatography

NASA Astrophysics Data System (ADS)

Bogoslovskii, S. Yu.; Serdan, A. A.

2016-03-01

The structural and geometric parameters of a silica matrix (SM) for the synthesis of heterosurface adsorbents (HAs) are optimized. Modification is performed by shielding the external surfaces of alkyl-modified silica (AS) using human serum albumin and its subsequent crosslinking. The structural and geometric characteristics of the SM, AS, and HA are measured via low-temperature nitrogen adsorption. It is found that the structural characteristics of AS pores with diameters D < 6 nm do not change during HA synthesis, while the volume of pores with diameters of 6 nm < D < 9 nm shrinks slightly due to the adsorption of albumin in the pore orifices. It is established that the volume of pores with diameters D > 9 nm reduces significantly due to adsorption of albumin. It is concluded that silica gel with a maximum pore size distribution close to 5 nm and a minimal proportion of pores with D > 9 nm is optimal for HA synthesis; this allows us to achieve the greatest similarity between the chromatographic retention parameters for HA and AS. The suitability of the synthesized adsorbents for analyzing drugs in biological fluids through direct sample injection is confirmed by chromatography. It was found that the percentage of the protein fraction detected at the outlet of the chromatographic column is 98%.

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

Thrombomodulin exerts cytoprotective effect on low-dose UVB-irradiated HaCaT cells

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

Iwata, Masahiro; Laboratory of Vascular Medicine, Department of Cardiovascular and Respiratory Disorders Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520; Kawahara, Ko-ichi

Thrombomodulin (TM) is an endothelial cell surface anticoagulant glycoprotein that performs antimetastatic, angiogenic, adhesive, and anti-inflammatory functions in various tissues. It is also expressed in epidermal keratinocytes. We found that a physiological dose (10 mJ/cm{sup 2}) of mid-wavelength ultraviolet irradiation (UVB) significantly induced TM expression via the p38mitogen-activated protein kinase (MAPK)/cyclic AMP response element (CRE) signaling pathway in the epidermal keratinocyte cell line HaCaT; this shows that TM regulates the survival of HaCaT cells. SB203580, a p38MAPK inhibitor, significantly decreased TM expression and the viability of cells exposed to UVB. Furthermore, overexpression of TM markedly increased cell viability, and itmore » was abrogated by TM small interfering RNA (siRNA), suggesting that TM may play an important role in exerting cytoprotective effect on epidermal keratinocytes against low-dose UVB.« less

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 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.

Minor histocompatibility antigen HA-1 and HA-2 polymorphisms in Taiwan: frequency and application in hematopoietic stem cell transplantation.

PubMed

Lio, Hoi-Yan; Tang, Jih-Luh; Wu, Jui; Wu, Shang-Ju; Lin, Chun-Ying; Yang, Ya-Chien

2010-09-01

Minor histocompatibility antigens influence the occurrence of graft-vs.-host disease and graft-vs.-leukemia effects after hematopoietic stem cell transplantation (HSCT). We determined the population frequencies of HA-1 and HA-2 alleles in Taiwan and exploited their potential applications in allogeneic HSCT. HA-1 and HA-2 were genotyped using polymerase chain reaction and restriction fragment length polymorphism in healthy controls (221 for HA-1 and 306 for HA-2) and HLA-matched donor-recipient sibling pairs with HSCT (92 for HA-1 and 38 for HA-2). The association of genetic polymorphisms with HSCT outcome was evaluated by univariate and multivariate analyses. The allele frequencies in controls were 35.3% and 64.7% for HA-1(H) and HA-1(R), and 89.0% and 11.0% for HA-2(V) and HA-2(M), respectively. HA-1 disparity was denoted in 16.3% of HLA-matched donor-recipient sibling pairs, while it was not associated with HSCT outcome. HA-2 disparity was not observed in the donor-recipient pairs studied. The possibilities of using HA-1 and HA-2 variabilities as molecular markers for hematopoietic chimerism after HSCT were 39.2% and 18.4%, respectively. Our data provide the information on allele and genotype frequencies of HA-1 and HA-2 in a Taiwanese population, and suggest that prospective genomic typing for HA-1 and HA-2 alleles of the donor and recipient could be a useful approach for molecular identification of hematopoietic chimerism after HSCT, rather than prognosis of clinical outcome.

Synthesis and Characterization of Hydroxyapatite-Collagen-Chitosan (HA/Col/Chi) Composite Coated on Ti6Al4V

NASA Astrophysics Data System (ADS)

Charlena; Bikharudin, Ahmad; Wahyudi, Setyanto Tri

2018-01-01

HA-collagen-chitosan (HA/col/chi) composite is developed to increase bioactivity adhesiveness between the metal and the material composite and to improve corrosion resistance. The Ti6Al4V alloy was coated by soaking in HA/col/chi composite at room temperature and then allowed to stand for 5, 6, and 7 days. Diffraction pattern analysis of the coated Ti6Al4V alloy showed that the dominant phase were HA and Ti6Al4V alloy. Corrosion resistance test in media by using 0.9% NaCl showed the corrosion rate at the level of 0.3567 mpy, which was better than that of the uncoated Ti6Al4V alloy (0.4152 mpy). In vitro cytocompatibility assay on endothelial cell of calf pulmonary artery endothelium (CPAE) (ATCC-CCL 209) showed there was no toxicity in the cell culture with the percent inhibition of 33.33% after 72 hours of incubation.

Therapeutic potential of monoacylglycerol lipase inhibitors.

PubMed

Mulvihill, Melinda M; Nomura, Daniel K

2013-03-19

Marijuana and aspirin have been used for millennia to treat a wide range of maladies including pain and inflammation. Both cannabinoids, like marijuana, that exert anti-inflammatory action through stimulating cannabinoid receptors, and cyclooxygenase (COX) inhibitors, like aspirin, that suppress pro-inflammatory eicosanoid production have shown beneficial outcomes in mouse models of neurodegenerative diseases and cancer. Both cannabinoids and COX inhibitors, however, have untoward effects that discourage their chronic usage, including cognitive deficits and gastrointestinal toxicity, respectively. Recent studies have uncovered that the serine hydrolase monoacylglycerol lipase (MAGL) links the endocannabinoid and eicosanoid systems together through hydrolysis of the endocannabinoid 2-arachidonoylglycerol (2-AG) to provide the major arachidonic acid (AA) precursor pools for pro-inflammatory eicosanoid synthesis in specific tissues. Studies in recent years have shown that MAGL inhibitors elicit anti-nociceptive, anxiolytic, and anti-emetic responses and attenuate precipitated withdrawal symptoms in addiction paradigms through enhancing endocannabinoid signaling. MAGL inhibitors have also been shown to exert anti-inflammatory action in the brain and protect against neurodegeneration through lowering eicosanoid production. In cancer, MAGL inhibitors have been shown to have anti-cancer properties not only through modulating the endocannabinoid-eicosanoid network, but also by controlling fatty acid release for the synthesis of protumorigenic signaling lipids. Thus, MAGL serves as a critical node in simultaneously coordinating multiple lipid signaling pathways in both physiological and disease contexts. This review will discuss the diverse (patho)physiological roles of MAGL and the therapeutic potential of MAGL inhibitors in treating a vast array of complex human diseases. Copyright © 2012 Elsevier Inc. All rights reserved.

Design and Synthesis of Potent “Sulfur-free” Transition State Analogue Inhibitors of 5′-Methylthioadenosine Nucleosidase and 5′-Methylthioadenosine Phosphorylase

PubMed Central

Longshaw, Alistair I.; Adanitsch, Florian; Gutierrez, Jemy A.; Evans, Gary B.; Tyler, Peter C.; Schramm, Vern L.

2013-01-01

5′-Methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) is a dual substrate bacterial enzyme involved in S-adenosylmethionine (SAM)-related quorum sensing pathways that regulates virulence in many bacterial species. MTANs from many bacteria are directly involved in the quorum sensing mechanism by regulating the synthesis of autoinducer molecules that are used by bacterial communities to communicate. In humans, 5′-methylthioadenosine phosphorylase (MTAP) is involved in polyamine biosynthesis as well as in purine and SAM salvage pathways and thus has been identified as an anticancer target. Previously we have described the synthesis and biological activity of several aza-C-nucleoside mimics with a sulfur atom at the 5′ position that are potent E. coli MTAN and human MTAP inhibitors. Because of the possibility that the sulfur may affect bioavailability we were interested in synthesizing “sulfur-free” analogues. Herein we describe the preparation of a series of “sulfur-free” transition state analogues inhibitors, of E. coli MTAN and human MTAP that have low nano- to pico-molar dissociation constants and are potentially novel bacterial anti-infective and anti-cancer drug candidates. PMID:20718423

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

PubMed Central

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

2013-01-01

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

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

PubMed

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

2010-09-01

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

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 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.

Differential osteogenic activity of osteoprogenitor cells on HA and TCP/HA scaffold of tissue engineered bone.

PubMed

Ng, Angela M H; Tan, K K; Phang, M Y; Aziyati, O; Tan, G H; Isa, M R; Aminuddin, B S; Naseem, M; Fauziah, O; Ruszymah, B H I

2008-05-01

Biomaterial, an essential component of tissue engineering, serves as a scaffold for cell attachment, proliferation, and differentiation; provides the three dimensional (3D) structure and, in some applications, the mechanical strength required for the engineered tissue. Both synthetic and naturally occurring calcium phosphate based biomaterial have been used as bone fillers or bone extenders in orthopedic and reconstructive surgeries. This study aims to evaluate two popular calcium phosphate based biomaterial i.e., hydroxyapatite (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) granules as scaffold materials in bone tissue engineering. In our strategy for constructing tissue engineered bone, human osteoprogenitor cells derived from periosteum were incorporated with human plasma-derived fibrin and seeded onto HA or TCP/HA forming 3D tissue constructs and further maintained in osteogenic medium for 4 weeks to induce osteogenic differentiation. Constructs were subsequently implanted intramuscularly in nude mice for 8 weeks after which mice were euthanized and constructs harvested for evaluation. The differential cell response to the biomaterial (HA or TCP/HA) adopted as scaffold was illustrated by the histology of undecalcified constructs and evaluation using SEM and TEM. Both HA and TCP/HA constructs showed evidence of cell proliferation, calcium deposition, and collagen bundle formation albeit lesser in the former. Our findings demonstrated that TCP/HA is superior between the two in early bone formation and hence is the scaffold material of choice in bone tissue engineering. Copyright 2007 Wiley Periodicals, Inc.

F8 and F9 mutations in US haemophilia patients: correlation with history of inhibitor and race/ethnicity.

PubMed

Miller, C H; Benson, J; Ellingsen, D; Driggers, J; Payne, A; Kelly, F M; Soucie, J M; Craig Hooper, W

2012-05-01

Both genetic and treatment-related risk factors contribute to the development of inhibitors in haemophilia. An inhibitor surveillance system piloted at 12 US sites has the goal of assessing risk factors through prospective data collection. This report examines the relationship of genotype and race/ethnicity to history of inhibitor in a large cohort of US haemophilia patients. Mutation analysis was performed on 676 haemophilia A (HA) and 153 haemophilia B (HB) patients by sequencing, Multiplex Ligation-dependent Probe Amplification, and PCR for inversions in F8 introns 22 (inv22) and 1 (inv1). Two HB patients with deletions had history of inhibitor. In severe HA, frequency of history of inhibitor was: large deletion 57.1%, splice site 35.7%, inv22 26.8%, nonsense 24.5%, frameshift 12.9%, inv1 11.1% and missense 9.5%. In HA, 19.6% of 321 White non-Hispanics (Whites), 37.1% of 35 Black non-Hispanics (Blacks) and 46.9% of 32 Hispanics had history of inhibitor (P = 0.0003). Mutation types and novel mutation rates were similar across ethnicities. When F8 haplotypes were constructed, Whites and Hispanics showed only H1 and H2. Within H1, history of inhibitor was 12.4% in Whites, 40.0% in Blacks (P = 0.009) and 32.4% in Hispanics (P = 0.002). Inhibitor frequency is confirmed to vary by mutation type and race in a large US population. White patients with history of inhibitor did not exhibit rare F8 haplotypes. F8 gene analysis did not reveal a cause for the higher inhibitor frequencies in Black and Hispanic patients. © 2011 Blackwell Publishing Ltd.

Synthesis of novel diarylamino-1,3,5-triazine derivatives as FAK inhibitors with anti-angiogenic activity.

PubMed

Dao, Pascal; Jarray, Rafika; Le Coq, Johanne; Lietha, Daniel; Loukaci, Ali; Lepelletier, Yves; Hadj-Slimane, Réda; Garbay, Christiane; Raynaud, Françoise; Chen, Huixiong

2013-08-15

We report herein the synthesis of novel diarylamino-1,3,5-triazine derivatives as FAK (focal adhesion kinase) inhibitors and the evaluation of their anti-angiogenic activity on HUVEC cells. Generally, the effects of these compounds on endothelial cells could be correlated with their kinase inhibitory activity. The most efficient compounds displayed inhibition of viability against HUVEC cells in the micromolar range, as observed with TAE-226, which was designed by Novartis Pharma AG. X-ray crystallographic analysis of the co-crystal structure for compound 34 revealed that the mode of interaction with the FAK kinase domain is highly similar to that observed in the complex of TAE-226. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana

PubMed Central

Zhao, Yue; Liu, Zhiyong; Liu, Chenfeng; Hu, Zhipeng

2017-01-01

Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana. PMID:28194424

Rational design of nitrofuran derivatives: Synthesis and valuation as inhibitors of Trypanosoma cruzi trypanothione reductase.

PubMed

Arias, D G; Herrera, F E; Garay, A S; Rodrigues, D; Forastieri, P S; Luna, L E; Bürgi, M D L M; Prieto, C; Iglesias, A A; Cravero, R M; Guerrero, S A

2017-01-05

The rational design and synthesis of a series of 5-nitro-2-furoic acid analogues are presented. The trypanocidal activity against epimastigote forms of Trypanosoma cruzi and the toxic effects on human HeLa cells were tested. Between all synthetic compounds, three of thirteen had an IC 50 value in the range of Nfx, but compound 13 exhibited an improved effect with an IC 50 of 1.0 ± 0.1 μM and a selective index of 70 in its toxicity against HeLa cells. We analyzed the activity of compounds 8, 12 and 13 to interfere in the central redox metabolic pathway in trypanosomatids, which is dependent of reduced trypanothione as the major pivotal thiol. The three compounds behaved as better inhibitors of trypanothione reductase than Nfx (Ki values of 118 μM, 61 μM and 68 μM for 8, 12 and 13, respectively, compared with 245 μM for Nfx), all following an uncompetitive enzyme inhibition pattern. Docking analysis predicted a binding of inhibitors to the enzyme-substrate complex with binding energy calculated in-silico that supports such molecular interaction. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Design, Synthesis, and Properties of a Potent Inhibitor of Pseudomonas aeruginosa Deacetylase LpxC.

PubMed

Piizzi, Grazia; Parker, David T; Peng, Yunshan; Dobler, Markus; Patnaik, Anup; Wattanasin, Som; Liu, Eugene; Lenoir, Francois; Nunez, Jill; Kerrigan, John; McKenney, David; Osborne, Colin; Yu, Donghui; Lanieri, Leanne; Bojkovic, Jade; Dzink-Fox, JoAnn; Lilly, Maria-Dawn; Sprague, Elizabeth R; Lu, Yipin; Wang, Hongming; Ranjitkar, Srijan; Xie, Lili; Wang, Bing; Glick, Meir; Hamann, Lawrence G; Tommasi, Ruben; Yang, Xia; Dean, Charles R

2017-06-22

Over the past several decades, the frequency of antibacterial resistance in hospitals, including multidrug resistance (MDR) and its association with serious infectious diseases, has increased at alarming rates. Pseudomonas aeruginosa is a leading cause of nosocomial infections, and resistance to virtually all approved antibacterial agents is emerging in this pathogen. To address the need for new agents to treat MDR P. aeruginosa, we focused on inhibiting the first committed step in the biosynthesis of lipid A, the deacetylation of uridyldiphospho-3-O-(R-hydroxydecanoyl)-N-acetylglucosamine by the enzyme LpxC. We approached this through the design, synthesis, and biological evaluation of novel hydroxamic acid LpxC inhibitors, exemplified by 1, where cytotoxicity against mammalian cell lines was reduced, solubility and plasma-protein binding were improved while retaining potent anti-pseudomonal activity in vitro and in vivo.

PP2B and ERK1/2 regulate hyaluronan synthesis of HT168 and WM35 human melanoma cell lines.

PubMed

Katona, Éva; Juhász, Tamás; Somogyi, Csilla Szűcs; Hajdú, Tibor; Szász, Csaba; Rácz, Kálmán; Kókai, Endre; Gergely, Pál; Zákány, Róza

2016-03-01

Hyaluronan (HA) is the major glycosaminoglycan component of the extracellular matrix in either normal or malignant tissues and it may affect proliferation, motility and differentiation of various cell types. Three isoforms of plasma membrane-bound hyaluronan synthases (HAS 1, 2 and 3) secrete and simultaneously bind pericellular HA. HAS enzymes are subjects of post-translational protein phosphorylation which is believed to regulate their enzymatic activity. In this study, we investigated the HA homeostasis of normal human epidermal melanocytes, HT168 and WM35 human melanoma cell lines and melanoma metastases. HAS2 and HAS3 were detected in all the samples, while the expression of HAS1 was not detectable in any case. Malignant tissue samples and melanoma cell lines contained extra- and intracellular HA abundantly but not normal melanocytes. Applying HA as a chemoattractant facilitated the migration of melanoma cells in Boyden chamber. The amount of HA was reduced upon the inhibition of calcineurin with cyclosporine A (CsA), while the inhibition of ERK1/2 with PD098059 elevated it in both cell lines. The signals of Ser/Thr phosphoproteins at 57 kD were stronger after CsA treatment, while a markedly weaker signal was detected upon inhibition of the MAPK pathway. Our results suggest opposing effects of the two investigated enzymes on the HA homeostasis of melanoma cells. We propose that the dephosphorylation of HAS enzymes targeted by PP2B augments HA production, while their phosphorylation by the activity of MAPK pathway reduces HA synthesis. As the expression of the HA receptor RHAMM was also significantly enhanced by PD098059, the MAPK pathway exerted a complex attenuating effect on HA signalling in the investigated melanoma cells. This observation suggests that the application of MAPK-ERK pathway inhibitors requires a careful therapeutic design in melanoma treatment.

PP2B and ERK1/2 regulate hyaluronan synthesis of HT168 and WM35 human melanoma cell lines

PubMed Central

KATONA, ÉVA; JUHÁSZ, TAMÁS; SOMOGYI, CSILLA SZŰCS; HAJDÚ, TIBOR; SZÁSZ, CSABA; RÁCZ, KÁLMÁN; KÓKAI, ENDRE; GERGELY, PÁL; ZÁKÁNY, RÓZA

2016-01-01

Hyaluronan (HA) is the major glycosaminoglycan component of the extracellular matrix in either normal or malignant tissues and it may affect proliferation, motility and differentiation of various cell types. Three isoforms of plasma membrane-bound hyaluronan synthases (HAS 1, 2 and 3) secrete and simultaneously bind pericellular HA. HAS enzymes are subjects of post-translational protein phosphorylation which is believed to regulate their enzymatic activity. In this study, we investigated the HA homeostasis of normal human epidermal melanocytes, HT168 and WM35 human melanoma cell lines and melanoma metastases. HAS2 and HAS3 were detected in all the samples, while the expression of HAS1 was not detectable in any case. Malignant tissue samples and melanoma cell lines contained extra- and intracellular HA abundantly but not normal melanocytes. Applying HA as a chemoattractant facilitated the migration of melanoma cells in Boyden chamber. The amount of HA was reduced upon the inhibition of calcineurin with cyclosporine A (CsA), while the inhibition of ERK1/2 with PD098059 elevated it in both cell lines. The signals of Ser/Thr phosphoproteins at 57 kD were stronger after CsA treatment, while a markedly weaker signal was detected upon inhibition of the MAPK pathway. Our results suggest opposing effects of the two investigated enzymes on the HA homeostasis of melanoma cells. We propose that the dephosphorylation of HAS enzymes targeted by PP2B augments HA production, while their phosphorylation by the activity of MAPK pathway reduces HA synthesis. As the expression of the HA receptor RHAMM was also significantly enhanced by PD098059, the MAPK pathway exerted a complex attenuating effect on HA signalling in the investigated melanoma cells. This observation suggests that the application of MAPK-ERK pathway inhibitors requires a careful therapeutic design in melanoma treatment. PMID:26717964

Treatment with bindarit, an inhibitor of MCP-1 synthesis, protects mice against trinitrobenzene sulfonic acid-induced colitis.

PubMed

Bhatia, M; Landolfi, C; Basta, F; Bovi, G; Ramnath, R Devi; de Joannon, A Capezzone; Guglielmotti, A

2008-10-01

Chemokines play a fundamental role in trafficking and activation of leukocytes in colonic inflammation. We investigated the ability of bindarit, an inhibitor of monocyte chemoattractant protein-1 (MCP-1/CCL2) synthesis, to inhibit chemokine production by human intestinal epithelial cells (HT-29) and its effect in trinitro-benzene sulfonic acid (TNBS)-induced colitis in mice. HT-29 cells were incubated with bindarit in the presence of TNF-alpha/IFN-gamma and 24 h later supernatants were collected for MCP-1, IL-8 and RANTES measurement. A 1 mg enema of TNBS was given to BALB/c mice, and bindarit (100 mg/kg) was orally administered twice daily starting from two days before colitis induction. Weight loss, histology, and MCP-1 level and myeloperoxidase (MPO) activity in colon extracts were assessed. In HT-29 cells, bindarit concentration-dependently and selectively inhibited MCP-1 secretion (as well as mRNA expression) primed by TNF-alpha/IFN-gamma. Moreover treatment with bindarit reduced clinical and histopathological severity of TNBS-induced colitis. These effects were associated with significant inhibition of MCP-1 and MPO in colon extracts. Bindarit exhibits a potent bioactivity in reducing leukocyte infiltration, down-regulating MCP-1 synthesis, and preventing the development of severe colitis in a mice model of TNBS-induced colitis. These observations suggest a potential use of MCP-1 synthesis blockers in intestinal inflammation in humans.

Synthesis, kinetic studies and molecular modeling of novel tacrine dimers as cholinesterase inhibitors.

PubMed

de Aquino, Roney Anderson Nascimento; Modolo, Luzia Valentina; Alves, Rosemeire Brondi; de Fátima, Ângelo

2013-12-28

This study presents the synthesis of 15 new tacrine dimers as well as the Ki and IC50 results, studies of the kinetic mechanism, and molecular docking analysis of the dimers in relation to the cholinesterases hAChE, hBChE, EeAChE and eqBChE. In addition to spectroscopic characterization, X-ray structure determination was performed for two of the new compounds. These new dimers were found to be mixed nanomolar inhibitors of the evaluated targets with a broad and significant selectivity profile, and these properties are dependent on both the type of the linker and the volume of the hydroacridine alicyclic ring. The results indicate that the aromatic linkers play a significant role in generating specific interactions with the half-gorge region of the catalytic center. Thus, these types of linkers can positively modulate the electronic properties of the tacrine dimers studied with an improvement of their cholinesterase inhibition activity.

DGAT inhibitors for obesity.

PubMed

Matsuda, Daisuke; Tomoda, Hiroshi

2007-10-01

Obesity is characterized by the accumulation of triacylglycerol in adipocytes. Diacylglycerol acyltransferase (DGAT) catalyzes the final reaction of triacylgycerol synthesis. Two isozymes of DGAT, DGAT1 and DGAT2, have been reported. Increased DGAT2 activity has a role in steatosis, while DGAT1 plays a role in very (V)LDL synthesis; increased plasma VLDL concentrations may promote obesity and thus DGAT1 is considered a potential therapeutic target of inhibition for obesity control. Several DGAT inhibitors of natural and synthetic origin have been reported, and their future prospect as anti-obesity drugs is discussed in this review.

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

PubMed

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

2014-07-01

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

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.

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.

In vitro testing of calcium phosphate (HA, TCP, and biphasic HA-TCP) whiskers.

PubMed

Jalota, Sahil; Bhaduri, Sarit B; Tas, A Cuneyt

2006-09-01

Calcium phosphate [single-phase hydroxyapatite (HA, Ca(10)(PO(4))(6)(OH)(2)), single-phase tricalcium phosphate (beta-TCP, Ca(3)(PO(4))(2)), and biphasic HA-TCP] whiskers were formed by using a novel microwave-assisted molten salt mediated process. Aqueous solutions containing NaNO(3), HNO(3), Ca(NO(3))(2) x 4H(2)O, and KH(2)PO(4) (with or without urea) were used as starting reagents. These solutions were irradiated in a household microwave oven for 5 min. As-recovered precursors were then simply stirred in water at room temperature for 1 h to obtain the whiskers of the desired calcium phosphate (CaP) bioceramics. These whiskers were evaluated, respectively, in vitro by (1) soaking those in synthetic body fluid (SBF) solutions at 37 degrees C for one week, and (2) performing cell attachment and total protein assay tests on the neat whiskers by using a mouse osteoblast cell line (7F2). beta-TCP, HA, and HA-TCP biphasic whiskers were all found to possess apatite-inducing ability when soaked in SBF. SBF-soaked whiskers were found to have BET surface areas ranging from 45 to 112 m(2)/g. Although the osteoblast viability and protein concentrations were found to be the highest on the neat HA whiskers, cells were attached and proliferated on all the whiskers.

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.

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.

Probing the Active Site of Candida Glabrata Dihydrofolate Reductase with High Resolution Crystal Structures and the Synthesis of New Inhibitors

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

Liu, J.; Bolstad, D; Smith, A

2009-01-01

Candida glabrata, a fungal strain resistant to many commonly administered antifungal agents, has become an emerging threat to human health. In previous work, we validated that the essential enzyme, dihydrofolate reductase, is a drug target in C. glabrata. Using a crystal structure of dihydrofolate reductase from C. glabrata bound to an initial lead compound, we designed a class of biphenyl antifolates that potently and selectively inhibit both the enzyme and the growth of the fungal culture. In this work, we explore the structure-activity relationships of this class of antifolates with four new high resolution crystal structures of enzyme:inhibitor complexes andmore » the synthesis of four new inhibitors. The designed inhibitors are intended to probe key hydrophobic pockets visible in the crystal structure. The crystal structures and an evaluation of the new compounds reveal that methyl groups at the meta and para positions of the distal phenyl ring achieve the greatest number of interactions with the pathogenic enzyme and the greatest degree of selectivity over the human enzyme. Additionally, antifungal activity can be tuned with substitution patterns at the propargyl and para-phenyl positions.« less

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).

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

In situ synthesis of luminescent carbon nanoparticles toward target bioimaging

NASA Astrophysics Data System (ADS)

Sharker, Shazid Md.; Kim, Sung Min; Lee, Jung Eun; Jeong, Ji Hoon; in, Insik; Lee, Kang Dea; Lee, Haeshin; Park, Sung Young

2015-03-01

This paper describes the in situ synthesis of single fluorescence carbon nanoparticles (FCNs) for target bioimaging applications derived from biocompatible hyaluronic acid (HA) without using common conjugation processes. FCNs formed via the dehydration of hyaluronic acid, which were obtained by carbonizing HA, and partially carbonized HA fluorescence carbon nanoparticles (HA-FCNs), formed by a lower degree of carbonization, show good aqueous solubility, small particle size (<20 nm) and different fluorescence intensities with a red shift. After confirming the cytotoxicity of HA-FCNs and FCNs, we carried out in vitro and in vivo bioimaging studies where HA-FCNs themselves functioned as single particle triggers in target imaging. The converted nanocrystal carbon particles from HA provide outstanding features for in vitro and in vivo new targeted delivery and diagnostic tools.This paper describes the in situ synthesis of single fluorescence carbon nanoparticles (FCNs) for target bioimaging applications derived from biocompatible hyaluronic acid (HA) without using common conjugation processes. FCNs formed via the dehydration of hyaluronic acid, which were obtained by carbonizing HA, and partially carbonized HA fluorescence carbon nanoparticles (HA-FCNs), formed by a lower degree of carbonization, show good aqueous solubility, small particle size (<20 nm) and different fluorescence intensities with a red shift. After confirming the cytotoxicity of HA-FCNs and FCNs, we carried out in vitro and in vivo bioimaging studies where HA-FCNs themselves functioned as single particle triggers in target imaging. The converted nanocrystal carbon particles from HA provide outstanding features for in vitro and in vivo new targeted delivery and diagnostic tools. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07422j

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.

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.

Inhibition of adenovirus DNA synthesis in vitro by sera from patients with systemic lupus erythematosus

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

Horwitz, M.S.; Friefeld, B.R.; Keiser, H.D.

1982-12-01

Sera containing antinuclear antibodies from patients with systemic lupus erythematosus (SLE) and related disorders were tested for their effect on the synthesis of adenovirus (Ad) DNA in an in vitro replication system. After being heated at 60/sup 0/C for 1 h, some sera from patients with SLE inhibited Ad DNA synthesis by 60 to 100%. Antibodies to double-stranded DNA were present in 15 of the 16 inhibitory sera, and inhibitory activity copurified with anti-double-stranded DNA in the immunoglobulin G fraction. These SLE sera did not inhibit the DNA polymerases ..cap alpha.., BETA, ..gamma.. and had no antibody to the 72,000-daltonmore » DNA-binding protein necessary for Ad DNA synthesis. The presence of antibodies to single-stranded DNA and a variety of saline-extractable antigens (Sm, Ha, nRNP, and rRNP) did not correlate with SLE serum inhibitory activity. Methods previously developed for studying the individual steps in Ad DNA replication were used to determine the site of inhibition by the SLE sera that contained antibody to double-stranded DNA. Concentrations of the SLE inhibitor that decreased the elongation of Ad DNA by greater than 85% had no effect on either the initiation of Ad DNA synthesis or the polymerization of the first 26 deoxyribonucleotides.« less

Discovery of Imidazo[1,2-a]pyridine Ethers and Squaramides as Selective and Potent Inhibitors of Mycobacterial Adenosine Triphosphate (ATP) Synthesis.

PubMed

Tantry, Subramanyam J; Markad, Shankar D; Shinde, Vikas; Bhat, Jyothi; Balakrishnan, Gayathri; Gupta, Amit K; Ambady, Anisha; Raichurkar, Anandkumar; Kedari, Chaitanyakumar; Sharma, Sreevalli; Mudugal, Naina V; Narayan, Ashwini; Naveen Kumar, C N; Nanduri, Robert; Bharath, Sowmya; Reddy, Jitendar; Panduga, Vijender; Prabhakar, K R; Kandaswamy, Karthikeyan; Saralaya, Ramanatha; Kaur, Parvinder; Dinesh, Neela; Guptha, Supreeth; Rich, Kirsty; Murray, David; Plant, Helen; Preston, Marian; Ashton, Helen; Plant, Darren; Walsh, Jarrod; Alcock, Peter; Naylor, Kathryn; Collier, Matthew; Whiteaker, James; McLaughlin, Robert E; Mallya, Meenakshi; Panda, Manoranjan; Rudrapatna, Suresh; Ramachandran, Vasanthi; Shandil, Radha; Sambandamurthy, Vasan K; Mdluli, Khisi; Cooper, Christopher B; Rubin, Harvey; Yano, Takahiro; Iyer, Pravin; Narayanan, Shridhar; Kavanagh, Stefan; Mukherjee, Kakoli; Balasubramanian, V; Hosagrahara, Vinayak P; Solapure, Suresh; Ravishankar, Sudha; Hameed P, Shahul

2017-02-23

The approval of bedaquiline to treat tuberculosis has validated adenosine triphosphate (ATP) synthase as an attractive target to kill Mycobacterium tuberculosis (Mtb). Herein, we report the discovery of two diverse lead series imidazo[1,2-a]pyridine ethers (IPE) and squaramides (SQA) as inhibitors of mycobacterial ATP synthesis. Through medicinal chemistry exploration, we established a robust structure-activity relationship of these two scaffolds, resulting in nanomolar potencies in an ATP synthesis inhibition assay. A biochemical deconvolution cascade suggested cytochrome c oxidase as the potential target of IPE class of molecules, whereas characterization of spontaneous resistant mutants of SQAs unambiguously identified ATP synthase as its molecular target. Absence of cross resistance against bedaquiline resistant mutants suggested a different binding site for SQAs on ATP synthase. Furthermore, SQAs were found to be noncytotoxic and demonstrated efficacy in a mouse model of tuberculosis infection.

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.

Effect of molecular weight of hyaluronic acid (HA) on viscoelasticity and particle texturing feel of HA dermal biphasic fillers.

PubMed

Chun, Cheolbyong; Lee, Deuk Yong; Kim, Jin-Tae; Kwon, Mi-Kyung; Kim, Young-Zu; Kim, Seok-Soon

2016-01-01

Hyaluronic acid (HA) dermal biphasic fillers are synthesized for their efficacy in correcting aesthetic defects such as wrinkles, scars and facial contouring defects. The fillers consist of crosslinked HA microspheres suspended in a noncrosslinked HA. To extend the duration of HAs within the dermis and obtain the particle texturing feel, HAs are crosslinked to obtain the suitable mechanical properties. Hyaluronic acid (HA) dermal biphasic fillers are prepared by mixing the crosslinked HA microspheres and the noncrosslinked HAs. The elastic modulus of the fillers increased with raising the volume fraction of the microspheres. The mechanical properties and the particle texturing feel of the fillers made from crosslinked HA (1058 kDa) microspheres suspended in noncrosslinked HA (1368 kDa) are successfully achieved, which are adequate for the fillers. Dermal biphasic HA fillers made from 1058 kDa exhibit suitable elastic moduli (211 to 420 Pa) and particle texturing feel (scale 7 ~ 9).

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

PubMed

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

2008-02-01

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

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.

Chitin synthesis inhibitors promote liver cancer cell metastasis via interfering with hypoxia-inducible factor 1α.

PubMed

Ning, Xia; Wang, Yue; Yan, Wei; Li, Guangke; Sang, Nan

2018-05-03

Chitin synthesis inhibitors (CSIs), as alternatives to conventional insecticides, have been in worldwide demand in recent years. However, little attention has been paid to the potential ecological safety and health risks of CSIs, especially their abilities to interfere with nonsexual hormone receptors such as hypoxia-inducible factor 1α (HIF-1α). In this work, we conducted a systematic study regarding the influence of CSIs on HIF-1α-related liver cancer cell metastasis. The dual-luciferase reporter gene assay revealed that two of fourteen CSIs exhibited dose-response HIF-1α agonistic activities at noncytotoxic concentrations with relative luciferase activity (RLA) values of 25.6% for diflubenzuron (DFB) and 20.9% for triflumuron (TFM). Following this result, in vitro bioassays demonstrated that both DFB and TFM stimulated HepG2 cell migration and invasion. This action was associated with the varied expression levels of genes involved in epithelial-to-mesenchymal transition (EMT) activation and extracellular matrix (ECM) degradation, such as the upregulation of fibronectin (FN1) and matrix metalloproteinase-2 (MMP-2) and the suppression of E-cadherin (E-cad) and tissue inhibitor of metalloproteinases-2 (TIMP-2). Moreover, changes in these EMT and ECM phenotype markers were dramatically blocked by a HIF-1α inhibitor (KC7F2), which further verified the involvement of HIF-1α in CSI-induced HepG2 cell metastasis. For the first time, our findings reveal that CSIs play crucial roles in promoting the metastasis of human liver cancer cells and that HIF-1α is potentially responsible for these changes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Solid State Reaction Synthesis of Si-HA as Potential Biomedical Material: An Endeavor to Enhance the Added Value of Indonesian Mineral Resources

NASA Astrophysics Data System (ADS)

Hartatiek; Yudyanto; Ratnasari, S. D.; Windari, R. Y.; Hidayat, N.

2017-05-01

In recent years, one of the most prominently investigated materials is hydroxyapatite (HA). It is because of its excellent properties for medical applications, essentially related to orthopedic. Also, the introduction of other materials to HA becomes another research focus of many leading scientists. In this present study, silicon with various concentrations was introduced, by means of solid state reaction route, to HA forming Si-HA. The crystal structure properties of the as-prepared samples were evaluated by X-ray diffractometer (XRD). Fourier Transform Infra Red (FTIR) spectroscopy data collection and analysis were done to investigate the functional groups within the samples. The microstructural characteristics as well as elemental mapping of the samples were captured by scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM-EDX). Vickers hardness test was also conducted to investigate the hardness properties of the samples. Furthermore, in vitro characterization-based bio resorbability of the samples in a simulated body fluid were also described. This study revealed that Indonesian limestone can be utilized as the raw material for synthesizing HA. The silicon has been successfully incorporated into phosphate site of the HA crystal. Conclusively, the Si-HA reported in this study shows good bioresorbability characteristic.

Design and synthesis of 1-(benzothiazol-5-yl)-1H-1,2,4-triazol-5-ones as protoporphyrinogen oxidase inhibitors.

PubMed

Zuo, Yang; Yang, Sheng-Gang; Luo, Yan-Ping; Tan, Ying; Hao, Ge-Fei; Wu, Qiong-You; Xi, Zhen; Yang, Guang-Fu

2013-06-01

Protoporphyrinogen oxidase (PPO, E.C. 1.3.3.4) is the action target for several structurally diverse herbicides. A series of novel 4-(difluoromethyl)-1-(6-halo-2-substituted-benzothiazol-5-yl)-3-methyl-1H-1,2,4-triazol-5(4H)-ones 2a-z were designed and synthesized via the ring-closure of two ortho-substituents. The in vitro bioassay results indicated that the 26 newly synthesized compounds exhibited good PPO inhibition effects with K(i) values ranging from 0.06 to 17.79 μM. Compound 2e, ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzo-thiazol-2-yl]thio}acetate, was the most potent inhibitor with K(i) value of 0.06 μM against mtPPO, comparable to (K(i)=0.03 μM) sulfentrazone. Further green house assays showed that compound 2f (K(i)=0.24 μM, mtPPO), ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzothiazol-2-yl]thio}propanoate, showed the most promising post-emergence herbicidal activity with broad spectrum even at concentrations as low as 37.5 gai/ha. Soybean exhibited tolerance to compound 2f at the dosages of 150 gai/ha, whereas they are susceptible to sulfentrazone even at 75 gai/ha. Thus, compound 2f might be a potential candidate as a new herbicide for soybean fields. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2016-12-01

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

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.

Design and Synthesis of Novel Small-molecule Inhibitors of the Hypoxia Inducible Factor Pathway

PubMed Central

Mooring, Suazette Reid; Jin, Hui; Devi, Narra S.; Jabbar, Adnan A.; Kaluz, Stefan; Liu, Yuan; Van Meir, Erwin G.; Wang, Binghe

2012-01-01

Hypoxia, a reduction in partial oxygen pressure, is a salient property of solid tumors. Hypoxia drives malignant progression and metastasis in tumors and participates in tumor resistance to radio- and chemotherapies. Hypoxia activates the hypoxia-inducible factor (HIF) family of transcription factors, which induce target genes that regulate adaptive biological processes such as anaerobic metabolism, cell motility and angiogenesis. Clinical evidence has demonstrated that expression of HIF-1 is strongly associated with poor patient prognosis and activation of HIF-1 contributes to malignant behavior and therapeutic resistance. Consequently, HIF-1 has become an important therapeutic target for inhibition by small molecules. Herein, we describe the design and synthesis of small molecules that inhibit the HIF-1 signaling pathway. Many of these compounds exhibit inhibitory activity in the nanomolar range. Separate mechanistic studies indicate that these inhibitors do not alter HIF-1 levels, but interfere with the HIF-1α/HIF-1β/p300/CBP complex formation by interacting with p300 and CBP. PMID:22032632

Trichomonas vaginalis Induces SiHa Cell Apoptosis by NF-κB Inactivation via Reactive Oxygen Species

PubMed Central

Quan, Juan-Hua; Kang, Byung-Hun; Yang, Jung-Bo; Rhee, Yun-Ee; Noh, Heung-Tae; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min

2017-01-01

Trichomonas vaginalis induces apoptosis in host cells through various mechanisms; however, little is known about the relationship between apoptosis, reactive oxygen species (ROS), and NF-κB signaling pathways in the cervical mucosal epithelium. Here, we evaluated apoptotic events, ROS production, and NF-κB activity in T. vaginalis-treated cervical mucosal epithelial SiHa cells, with or without specific inhibitors, using fluorescence microscopy, DNA fragmentation assays, subcellular fractionation, western blotting, and luciferase reporter assay. SiHa cells treated with live T. vaginalis at a multiplicity of infection of 5 (MOI 5) for 4 h produced intracellular and mitochondrial ROS in a parasite-load-dependent manner. Incubation with T. vaginalis caused DNA fragmentation, cleavage of caspase 3 and PARP, and release of cytochrome c into the cytoplasm. T. vaginalis-treated SiHa cells showed transient early NF-κB p65 nuclear translocation, which dramatically dropped at 4 h after treatment. Suppression of NF-κB activity was dependent on parasite burden. However, treatment with the ROS scavenger, N-acetyl-C-cysteine (NAC), reversed the effect of T. vaginalis on apoptosis and NF-κB inactivation in SiHa cells. Taken together, T. vaginalis induces apoptosis in human cervical mucosal epithelial cells by parasite-dose-dependent ROS production through an NF-κB-regulated, mitochondria-mediated pathway. PMID:29410962

Molecular aspects of zygotic embryogenesis in sunflower (Helianthus annuus L.): correlation of positive histone marks with HaWUS expression and putative link HaWUS/HaL1L.

PubMed

Salvini, Mariangela; Fambrini, Marco; Giorgetti, Lucia; Pugliesi, Claudio

2016-01-01

The link HaWUS/ HaL1L , the opposite transcriptional behavior, and the decrease/increase in positive histone marks bond to both genes suggest an inhibitory effect of WUS on HaL1L in sunflower zygotic embryos. In Arabidopsis, a group of transcription factors implicated in the earliest events of embryogenesis is the WUSCHEL-RELATED HOMEOBOX (WOX) protein family including WUSCHEL (WUS) and other 14 WOX protein, some of which contain a conserved WUS-box domain in addition to the homeodomain. WUS transcripts appear very early in embryogenesis, at the 16-cell embryo stage, but gradually become restricted to the center of the developing shoot apical meristem (SAM) primordium and continues to be expressed in cells of the niche/organizing center of SAM and floral meristems to maintain stem cell population. Moreover, WUS has decisive roles in the embryonic program presumably promoting the vegetative-to-embryonic transition and/or maintaining the identity of the embryonic stem cells. However, data on the direct interaction between WUS and key genes for seed development (as LEC1 and L1L) are not collected. The novelty of this report consists in the characterization of Helianthus annuus WUS (HaWUS) gene and in its analysis regarding the pattern of the methylated lysine 4 (K4) of the Histone H3 and of the acetylated histone H3 during the zygotic embryo development. Also, a parallel investigation was performed for HaL1L gene since two copies of the WUS-binding site (WUSATA), previously identified on HaL1L nucleotide sequence, were able to be bound by the HaWUS recombinant protein suggesting a not described effect of HaWUS on HaL1L transcription.

A novel pathogenic mechanism of highly pathogenic avian influenza H5N1 viruses involves hemagglutinin mediated resistance to serum innate inhibitors.

PubMed

Panaampon, Jutatip; Ngaosuwankul, Nathamon; Suptawiwat, Ornpreya; Noisumdaeng, Pirom; Sangsiriwut, Kantima; Siridechadilok, Bunpote; Lerdsamran, Hatairat; Auewarakul, Prasert; Pooruk, Phisanu; Puthavathana, Pilaipan

2012-01-01

In this study, the effect of innate serum inhibitors on influenza virus infection was addressed. Seasonal influenza A(H1N1) and A(H3N2), 2009 pandemic A(H1N1) (H1N1pdm) and highly pathogenic avian influenza (HPAI) A(H5N1) viruses were tested with guinea pig sera negative for antibodies against all of these viruses as evaluated by hemagglutination-inhibition and microneutralization assays. In the presence of serum inhibitors, the infection by each virus was inhibited differently as measured by the amount of viral nucleoprotein produced in Madin-Darby canine kidney cells. The serum inhibitors inhibited seasonal influenza A(H3N2) virus the most, while the effect was less in seasonal influenza A(H1N1) and H1N1pdm viruses. The suppression by serum inhibitors could be reduced by heat inactivation or treatment with receptor destroying enzyme. In contrast, all H5N1 strains tested were resistant to serum inhibitors. To determine which structure (hemagglutinin (HA) and/or neuraminidase (NA)) on the virus particles that provided the resistance, reverse genetics (rg) was applied to construct chimeric recombinant viruses from A/Puerto Rico/8/1934(H1N1) (PR8) plasmid vectors. rgPR8-H5 HA and rgPR8-H5 HANA were resistant to serum inhibitors while rgPR8-H5 NA and PR8 A(H1N1) parental viruses were sensitive, suggesting that HA of HPAI H5N1 viruses bestowed viral resistance to serum inhibition. These results suggested that the ability to resist serum inhibition might enable the viremic H5N1 viruses to disseminate to distal end organs. The present study also analyzed for correlation between susceptibility to serum inhibitors and number of glycosylation sites present on the globular heads of HA and NA. H3N2 viruses, the subtype with highest susceptibility to serum inhibitors, harbored the highest number of glycosylation sites on the HA globular head. However, this positive correlation cannot be drawn for the other influenza subtypes.

New halogenated phenylcoumarins as tyrosinase inhibitors.

PubMed

Matos, Maria João; Santana, Lourdes; Uriarte, Eugenio; Delogu, Giovanna; Corda, Marcella; Fadda, Maria Benedetta; Era, Benedetta; Fais, Antonella

2011-06-01

With the aim to find out structural features for the tyrosinase inhibitory activity, in the present communication we report the synthesis and pharmacological evaluation of a new series of phenylcoumarin derivatives with different number of hydroxyl or ether groups and bromo substituent in the scaffold. The synthesized compounds 5-12 were evaluated as mushroom tyrosinase inhibitors showing, two of them, lower IC(50) than the umbelliferone. Compound 12 (IC(50)=215 μM) is the best tyrosinase inhibitor of this series. Copyright © 2011 Elsevier Ltd. All rights reserved.

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, 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.

The Impact of HA Oligomer Content on Physical, Mechanical, and Biologic Properties of Divinyl Sulfone-Crosslinked HA Hydrogels

PubMed Central

Ibrahim, Samir; Kang, Qian K; Ramamurthi, Anand

2009-01-01

In recent studies, we showed that exogenous hyaluronic acid oligomers (HA-o) stimulate functional endothelialization, though native long-chain HA is more bioinert and possibly more biocompatible. Thus, in this study, hydrogels containing high molecular weight (HMW) HA (1×106 Da) and HA oligomer mixtures (HA-o: 0.75–10 kDa) were created by crosslinking with divinyl sulfone (DVS). The incorporation of HA oligomers was found to compromise the physical and mechanical properties of the gels (rheology, apparent crosslinking density, swelling ratio, degradation) and to very mildly enhance inflammatory cell recruitment in vivo; increasing the DVS crosslinker content within the gels in general, had the opposite effect, though the relatively high concentration of DVS within these gels (necessary to create a solid gel) also stimulated a mild sub-cutaneous inflammatory response in vivo and VCAM-1 expression by ECs cultured atop; ICAM-expression levels remained very low irrespective extent of DVS crosslinking or HA-o content. The greatest EC attachment and proliferation (MTT assay) was observed on gels that contained the highest amount of HA-o. The study shows that the beneficial EC response to HA oligomers and biocompatibility of HA is mostly unaltered by their chemical derivatization and crosslinking into a hydrogel. However, the study also demonstrates that the relatively high concentrations of DVS, necessary to create solid gels, compromises their biocompatibility. Moreover, the poor mechanics of even these heavily crosslinked gels, in the context of vascular implantation, necessitates the investigation of other, more appropriate crosslinking agents. Alternately, the outcomes of this study may be used to guide an approach based on chemical immobilization and controlled surface-presentation of both bioactive HA oligomers and more biocompatible HMW HAon synthetic or tissue engineered grafts already in use, without the use of a crosslinker, so that improved, predictable

Aurintricarboxylic acid is a potent inhibitor of phosphofructokinase.

PubMed Central

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

1989-01-01

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

Mechanochemical Synthesis of Hydroxyapatite and Its Modifications: Composition, Structure, and Properties

NASA Astrophysics Data System (ADS)

Chaikina, M. V.; Bulina, N. V.; Ishchenko, A. V.; Prosanov, I. Yu.

2014-02-01

The mechanochemical method is used to synthesize samples of hydroxyapatite (HA) with substitution of the phosphate ion by silicate and zirconate ions, and substitution of calcium ions by copper ions. In the process of mechanochemical synthesis, carbonate ions and water molecules are incorporated into the structure of HA due to interaction of components of the reaction mixture with air. Intrusion of carbonate into the structure of HA is a competing process with modification of apatite by silicate and zirconate anions; therefore, the composition of the product during synthesis differs from the prescribed one. After annealing of the samples, the composition of the anion-modified HA can be described by the formula Са10(РО4)6- х (АО4) х (ОН)2- х , where (АО4)4- is the modifying anion. Substitution of calcium by copper ions localized at the Са1 position has been detected. Silver ions are not incorporated into the structure of HA, but are distributed in the apatite matrix in the form of nanocrystals of metallic silver.

Activity-guided separation and characterization of new halocin HA3 from fermented broth of Haloferax larsenii HA3.

PubMed

Kumar, Vijay; Tiwari, Santosh Kumar

2017-05-01

Haloferax larsenii HA3 was able to grow optimally in HS medium containing 15% NaCl, at pH 7.2 and 42 °C in aerobic conditions. Strain HA3 was found to be round shape, Gram-negative, catalase-positive, sensitive to bile acid, and resistant to chloramphenicol, and could not utilize arginine. The lipid profile revealed the presence of glycerol diether moiety (GDEM) suggesting Haloarchaea characteristics. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that it was closely related to H. larsenii ZJ206. Interestingly, strain HA3 was found to produce halocin HA3 which was purified using ultrafiltration and chromatography. It was found to be stable up to 80 °C, pH 2.0-10.0, organic solvents, surfactants, and detergents tested. However, the activity of halocin HA3 was completely reduced in the presence of proteinase K and trypsin. It was found to be halocidal against H. larsenii HA10, rupturing cell boundary and leading to cell death. The molecular weight of halocin HA3 was found to be ~13 kDa and MALDI-TOF MS/MS analysis suggested no homology with known halocins. The N-terminal ten amino-acid residues, NH 2 MNLGIILETN-COOH, suggested a new/novel halocin. These properties of halocin HA3 may be applicable for control of Haloarchaea in environments and salted foods.

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.

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.

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.

Catalytic, Enantioselective Synthesis of Stilbene cis-Diamines: A Concise Preparation of (–)-Nutlin-3, a Potent p53/MDM2 Inhibitor

PubMed Central

Davis, Tyler A.

2012-01-01

The first highly diastereo- and enantioselective additions of aryl nitromethane pronucleophiles to aryl aldimines are described. Identification of an electron rich chiral Bis(Amidine) catalyst for this aza-Henry variant was key to this development, leading ultimately to differentially protected cis-stilbene diamines in two steps. This method then became the lynchpin for an enantioselective synthesis of (–)-Nutlin-3 (Hoffmann-LaRoche), a potent cis-imidazoline small molecule inhibitor of p53-MDM2 used extensively as a probe of cell biology and currently in drug development. PMID:22708054

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.

Specific inhibition of protein synthesis in the rabbit reticulocyte lysate by two types of oligoribonucleotides

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

Wagner, T.; Gross, M.; Sigler, P.B.

1986-05-01

The oligonucleotides AUG, AUGG and AUGA, i.e. homologues of the initiation codon, are recognized as initiation sites by the protein synthetic machinery of the reticulocyte lysate. They induce the accumulation of inactive initiation complexes (80S x AUG x Met-tRNA/sub 1//sup Met/) and thereby deprive the system of active ribosomes. The only dinucleotide that inhibits protein synthesis is CA. CA and all trinucleotides of the form XCA and CAX (where X=U, C,A or G) block chain elongation at a level of 10/sup -5/M. Interestingly, inhibition by XCA is transient, while that by CAX becomes progressively greater with time. This phenomenon canmore » be explained by a 3'exonucleolytic activity in the lysate. Upon 3'terminal cleavage the XCA trinucleotides will lose the inhibitory CA, whereas CAX trinucleotides will simply be converted to CA, the specific inhibitor. This has been confirmed experimentally, since CC(/sup 3/H)A is completely hydrolyzed to CpC and p(/sup 3/H)A after 15 minutes of incubation. The mode of action of CA, while unclear, may be mediated by its similarity to the 3'-terminus of tRNA.« less

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.

Behaviour of human mesenchymal stem cells on chemically synthesized HA-PCL scaffolds for hard tissue regeneration.

PubMed

D'Antò, Vincenzo; Raucci, Maria Grazia; Guarino, Vincenzo; Martina, Stefano; Valletta, Rosa; Ambrosio, Luigi

2016-02-01

Our goal was to characterize the response of human mesenchymal stem cells (hMSCs) to a novel composite scaffold for bone tissue engineering. The hydroxyapatite-polycaprolactone (HA-PCL) composite scaffolds were prepared by a sol-gel method at room temperature and the scaffold morphology was investigated by scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) to validate the synthesis process. The response of two different lines of hMSCs, bone-marrow-derived human mesenchymal stem cells (BMSCs) and dental pulp stem cells (DPSCs) in terms of cell proliferation and differentiation into the osteoblastic phenotype, was evaluated using Alamar blue assay, SEM, histology and alkaline phosphatase activity. Our results indicate that tissue engineering by means of composite HA-PCL scaffolds may represent a new therapeutic strategy to repair craniofacial bone defects. Copyright © 2013 John Wiley & Sons, Ltd.

Hyperglycaemia and aberrated insulin signalling stimulate tumour progression via induction of the extracellular matrix component hyaluronan.

PubMed

Twarock, Sören; Reichert, Christina; Peters, Ulrike; Gorski, Daniel J; Röck, Katharina; Fischer, Jens W

2017-08-15

Epidemiological studies have detected a higher incidence of various tumour entities in diabetic patients. However, the underlying mechanisms remain insufficiently understood. Glucose-derived pericellular and extracellular hyaluronan (HA) promotes tumour progression and development. In our study, we tested the hypothesis that a diabetic metabolic state, characterised by hyperglycaemia and concomitant aberrant insulin signalling, stimulates tumour progression via the induction of HA synthesis. In a streptozotocin-induced diabetic nude mouse tumour xenograft model, hyperglycaemia and lack of insulin caused an increased formation of tumour-associated HA-matrix, which in turn accelerated tumour progression and neoangiogenesis. This process was effectively attenuated by treatment with 4-methylumbelliferone, a pharmacological inhibitor of HA-synthesis. To define the mechanisms behind these in vivo observations, we investigated the impact of hyperglycaemia and insulin on the glucose metabolism in oesophageal squamous cell cancer cells (ESCC). Hyperglycaemia induced HA synthesis while insulin diminished HA production by directing glucose metabolites to glycolysis. Vice versa, inhibition of glycolysis, either by knockdown of the glycolytic key enzyme phosphofructokinase or by an experimental abrogation of insulin signalling (knockdown of the insulin receptor and long-term treatment with insulin) augmented HA synthesis. Consequently, these processes induced invasion, anchorage-independent growth and adhesion of ESCC to endothelial cells in vitro. Thus, the cellular shift in glucose usage from catabolism of glucose to anabolism of HA driven by hyperglycaemia and insulin resistance may represent an important link between diabetes and cancer progression. Hence, therapeutical inhibition of HA synthesis may represent a promising approach for tumour treatment in diabetic patients. © 2017 UICC.

Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming.

PubMed

Vaezi, Mohammad; Black, Cameron; Gibbs, David M R; Oreffo, Richard O C; Brady, Mark; Moshrefi-Torbati, Mohamed; Yang, Shoufeng

2016-05-26

Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK) has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA) composite with a unique configuration in which the bioactive phase (i.e., HA) distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility.

Fabrication of modified GIC: GIC-nanoSiO2-HA-ZrO2 using two different mixing methods

NASA Astrophysics Data System (ADS)

Ghazali, Nor Ainon Maziah; Bakar, Wan Zaripah Wan; Rahman, Ismail Ab; Masudi, Sam'an Malik

2017-12-01

Conventional glass ionomer cement (GIC) is among the mostly used material in dentistry but some modifications were needed due to its deficiencies such as low mechanical strength and opacity. In this study, a new nanocomposite, GIC-nanoSiO2-HA-ZrO2 was fabricated whereby zirconia is added to improve the hardness. The nanocomposite of SiO2-HA-ZrO2 was synthesized using two different mixing methods which are one pot and spatulation methods. One pot method involved the addition of zirconia nanopowder during the one pot synthesis of nanoSiO2-HA and spatulation method involved the addition of zirconia nanopowder by controlled grinding process using mortar and pestle. Different weight percentage from 1-20 % of nanoSiO2-HA-ZrO2 was added to GIC and the hardness was analyzed using Vickers Tester. The one pot method recorded the highest and significant hardness value at 3 % addition which is ˜75.27 HV (± 2.48) compared to spatulation method ˜69.53 HV (± 7.78) at p < 0.05. Scanning Electron Microscope image from one pot method showed less agglomeration of the nanopowder and nanozirconia is uniformly distributed. Within the limitation of this study, one pot method produced better GIC-nanoSiO2-HA-ZrO2 composite.

Irredundant Sequential Machines Via Optimal Logic Synthesis

DTIC Science & Technology

1989-10-01

1989 Irredundant Sequential Machines Via Optimal Logic Synthesis NSrinivas Devadas , Hi-Keung Tony Ma, A. Richard Newton, and Alberto Sangiovanni- S...Agency under contract N00014-87-K-0825, and a grant from AT & T Bell Laboratories. Author Information Devadas : Department of Electrical Engineering...Sequential Machines Via Optimal Logic Synthesis Srinivas Devadas * Hi-Keung Tony ha. A. Richard Newton and Alberto Sangiovanni-Viucentelli Department of

Three dehalogenases and physiological restraints in the biodegradation of haloalkanes by Arthrobacter sp. strain HA1.

PubMed Central

Scholtz, R; Messi, F; Leisinger, T; Cook, A M

1988-01-01

Arthrobacter sp. strain HA1 utilizes 18 C2-to-C8 1-haloalkanes for growth and synthesizes an inducible 1-bromoalkane debrominase of unknown physiological function (R. Scholtz, T. Leisinger, F. Suter, and A.M. Cook, J. Bacteriol. 169:5016-5021, 1987) in addition to an inducible 1-chlorohexane halidohydrolase which dehalogenates some 50 substrates, including alpha, omega-dihaloalkanes. alpha, omega-Dihaloalkanes were utilized by cultures of strain HA1 under certain conditions only. C9 and C8 homologs prevented growth. At suitable concentrations, C7-to-C5 homologs could serve as sole sources of carbon and energy for growth. C4 and C3 homologs could be utilized only in the presence of a second substrate (e.g., butanol), and the C2 homolog was not degraded. Kinetics of growth and substrate utilization indicated that cells of strain HA1 growing in butanol-salts medium could be used to test whether compounds induced the 1-chlorohexane halidohydrolase. No gratuitous induction of synthesis of the enzyme was observed. Many enzyme substrates (e.g., bromobenzene) did not induce synthesis of the enzyme, though the enzyme sequence to degrade the product (phenol) was present. Some inducers (e.g., bromomethane) were enzyme substrates but not growth substrates. In an attempt to find a physiological role for the 1-bromoalkane debrominase, we observed that several long-chain haloaliphatic compounds (greater than C9; e.g., 1-bromohexadecane and 1-chlorohexadecane) were utilized for growth and that induced cells could dehalogenate several 1-haloalkanes (at least C4 to C16). The dehalogenation of the long-chain compounds could not be assayed in the cell extract, so we presume that a third haloalkane dehalogenase was present.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3223767

The existence of imidazoline corrosion inhibitors

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

Martin, J.A.; Valone, F.W.

1985-05-01

Spectroscopic methods, i.e., Fourier transform infrared (FT-IR), carbon-13 nuclear magnetic reasonance (/sup 13/C NMR), and ultraviolet (UV) spectroscopy, were used to investigate the actual chemical composition of oilfield corrosion inhibitors. Inhibitor formulations consisting of an amide or imidazoline reacted with a dimer-trimer acid, along with an ethoxylated surfactant and an aromatic solvent, were used for these studies. /sup 13/C NMR and FT-IR spectra of these inhibitors, as well as spectra of pure imidazolines, showed that the imidazoline functional group was fairly rapidly hydrolyzed to the amide form. For instance, in FT-IR studies, the imine functional group decreased in intensity asmore » a function of time. Coincident with this was an increase in the intensities of the vibrational resonances attributed to the amide functionality. The relative molar ratio of imidazoline to amide in a corrosion inhibitor could be calculated via UV spectroscopy. Within a 20 day interval after inhibitor synthesis, this ratio decreased by a factor greater than 20. These results, as well as a discussion of their economic impact on oilfield corrosion inhibitor formulation, are presented in this paper.« less

Design, Synthesis and Inhibitory Activity of Photoswitchable RET Kinase Inhibitors

NASA Astrophysics Data System (ADS)

Ferreira, Rubén; Nilsson, Jesper R.; Solano, Carlos; Andréasson, Joakim; Grøtli, Morten

2015-05-01

REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attractive therapeutic target for small-molecule kinase inhibitors. Novel approaches, allowing external control of the activity of RET, would be key additions to the signal transduction toolbox. In this work, photoswitchable RET kinase inhibitors based on azo-functionalized pyrazolopyrimidines were developed, enabling photonic control of RET activity. The most promising compound displays excellent switching properties and stability with good inhibitory effect towards RET in cell-free as well as live-cell assays and a significant difference in inhibitory activity between its two photoisomeric forms. As the first reported photoswitchable small-molecule kinase inhibitor, we consider the herein presented effector to be a significant step forward in the development of tools for kinase signal transduction studies with spatiotemporal control over inhibitor concentration in situ.

Metabolic basis for the differential susceptibility of Gram-positive pathogens to fatty acid synthesis inhibitors

PubMed Central

Parsons, Joshua B.; Frank, Matthew W.; Subramanian, Chitra; Saenkham, Panatda; Rock, Charles O.

2011-01-01

The rationale for the pursuit of bacterial type 2 fatty acid synthesis (FASII) as a target for antibacterial drug discovery in Gram-positive organisms is being debated vigorously based on their ability to incorporate extracellular fatty acids. The regulation of FASII by extracellular fatty acids was examined in Staphylococcus aureus and Streptococcus pneumoniae, representing two important groups of pathogens. Both bacteria use the same enzymatic tool kit for the conversion of extracellular fatty acids to acyl-acyl carrier protein, elongation, and incorporation into phospholipids. Exogenous fatty acids completely replace the endogenous fatty acids in S. pneumoniae but support only 50% of phospholipid synthesis in S. aureus. Fatty acids overcame FASII inhibition in S. pneumoniae but not in S. aureus. Extracellular fatty acids strongly suppress malonyl-CoA levels in S. pneumoniae but not in S. aureus, showing a feedback regulatory system in S. pneumoniae that is absent in S. aureus. Fatty acids overcame either a biochemical or a genetic block at acetyl-CoA carboxylase (ACC) in S. aureus, confirming that regulation at the ACC step is the key difference between these two species. Bacteria that possess a stringent biochemical feedback inhibition of ACC and malonyl-CoA formation triggered by environmental fatty acids are able to circumvent FASII inhibition. However, if exogenous fatty acids do not suppress malonyl-CoA formation, FASII inhibitors remain effective in the presence of fatty acid supplements. PMID:21876172

The sunflower transcription factor HaHB11 confers tolerance to water deficit and salinity to transgenic Arabidopsis and alfalfa plants.

PubMed

Cabello, Julieta V; Giacomelli, Jorge I; Gómez, María C; Chan, Raquel L

2017-09-10

Homeodomain-leucine zipper (HD-Zip) transcription factors are unique to the plant kingdom; members of subfamily I are known to be involved in abiotic stress responses. HaHB11 belongs to this subfamily and it was previously shown that it is able to confer improved yield and tolerance to flooding via a quiescent strategy. Here we show that HaHB11 expression is induced by ABA, NaCl and water deficit in sunflower seedlings and leaves. Arabidopsis transgenic plants expressing HaHB11, controlled either by its own promoter or by the constitutive 35S CaMV, presented rolled leaves and longer roots than WT when grown under standard conditions. In addition, these plants showed wider stems and more vascular bundles. To deal with drought, HaHB11 transgenic plants closed their stomata faster and lost less water than controls, triggering an enhanced tolerance to such stress condition and also to salinity stress. Concomitantly, ABA-synthesis and sensing related genes were differentially regulated in HaHB11 transgenic plants. Either under long-term salinity stress or mild drought stress, HaHB11 transgenic plants did not exhibit yield penalties. Moreover, alfalfa transgenic plants were generated which also showed enhanced drought tolerance. Altogether, the results indicated that HaHB11 was able to confer drought and salinity tolerance via a complex mechanism which involves morphological, physiological and molecular changes. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of the 2-methylene analogue of the HRV 3C protease inhibitor thysanone (2-carbathysanone).

PubMed

Schünemann, Katrin; Furkert, Daniel P; Choi, Eun Cho; Connelly, Stephen; Fraser, John D; Sperry, Jonathan; Brimble, Margaret A

2014-02-14

The Human Rhinovirus (HRV) is the major aetiological agent for the common cold, for which only symptomatic treatment is available. HRV maturation and replication is entirely dependent on the activity of a virally encoded 3C protease that represents an attractive target for the development of therapeutics to treat the common cold. Herein we report the synthesis and biological evaluation of the 2-methylene analogue of the HRV 3C protease inhibitor (-)-thysanone (1) namely 2-carbathysanone (2), in an attempt to decipher the structural features in the natural product that are responsible for the 3C protease activity. 2-Carbathysanone (2) (and related analogues (±)-cis-23, (±)-cis-30, (±)-31) did not inhibit HRV 3C protease, indicating that the lactol functionality present in (-)-thysanone (1) is a critical structural feature required for inhibition.

Biomedical potential of chitosan/HA and chitosan/β-1,3-glucan/HA biomaterials as scaffolds for bone regeneration--A comparative study.

PubMed

Przekora, Agata; Palka, Krzysztof; Ginalska, Grazyna

2016-01-01

The aim of this work was to compare biomedical potential of chitosan/hydroxyapatite (chit/HA) and novel chitosan/β-1,3-glucan/hydroxyapatite (chit/glu/HA) materials as scaffolds for bone regeneration via characterization of their biocompatibility, porosity, mechanical properties, and water uptake behaviour. Biocompatibility of the scaffolds was assessed in direct-contact with the materials using normal human foetal osteoblast cell line. Cytotoxicity and osteoblast proliferation rate were evaluated. Porosity was assessed using computed microtomography analysis and mechanical properties were determined by compression testing. Obtained results demonstrated that chit/HA scaffold possessed significantly better mechanical properties (compressive strength: 1.23 MPa, Young's modulus: 0.46 MPa) than chit/glu/HA material (compressive strength: 0.26 MPa, Young's modulus: 0.25 MPa). However, addition of bacterial β-1,3-glucan to the chit/HA scaffold improved its flexibility and porosity. Moreover, chit/glu/HA scaffold revealed significantly higher water uptake capability (52.6% after 24h of soaking) compared to the chit/HA (30.7%) and thus can serve as a very good drug delivery carrier. Chit/glu/HA scaffold was also more favourable to osteoblast survival (near 100% viability after 24-h culture), proliferation, and spreading compared to the chit/HA (63% viability). The chit/glu/HA possesses better biomedical potential than chit/HA scaffold. Nevertheless, poor mechanical properties of the chit/glu/HA limit its application to non-load bearing implantation area. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and structural characterization of nano-hydroxyapatite biomaterials prepared by microwave processing

NASA Astrophysics Data System (ADS)

Ramli, Rosmamuhamadani; Arawi, Ainaa Zafirah Omar; Talari, Mahesh Kumar; Mahat, Mohd Muzamir; Jais, Umi Sarah

2012-07-01

Synthetic hydroxyapatite, (HA, Ca10(PO4)6(OH)2), is an attractive and widely utilized bio-ceramic material for orthopedic and dental implants because of its close resemblance of native tooth and bone crystal structure. Synthetic HA exhibits excellent osteoconductive properties. Osteoconductivity means the ability to provide the appropriate scaffold or template for bone formation. Calcium phosphate biomaterials [(HA), tri-calcium phosphate (TCP) and biphasic calcium phosphate (HA/TCP)] with appropriate three-dimensional geometry are able to bind and concentrate endogenous bone morphogenetic proteins in circulation, and may become osteoinductive and can be effective carriers of bone cell seeds. This HA can be used in bio-implants as well as drug delivery application due to the unique properties of HA. Biomaterials synthesized from the natural species like mussel shells have additional benefits such as high purity, less expensive and high bio compatibility. In this project, HA-nanoparticles of different crystallite size were prepared by microwave synthesis of precursors. High purity CaO was extracted from the natural mussel shells for the synthesis of nano HA. Dried nano HA powders were analyzed using X-Ray Diffraction (XRD) technique for the determination of crystal structure and impurity content. Scanning Electron Microscopic (SEM) investigation was employed for the morphological investigation of nano HA powders. From the results obtained, it was concluded that by altering the irradiation time, nano HA powders of different crystallite sizes and morphologies could be produced. Crystallite sizes calculated from the XRD patterns are found to be in the range of 10-55 nm depending on the irradiation time.

Size controlled hydroxyapatite and calcium carbonate particles: synthesis and their application as templates for SERS platform.

PubMed

Parakhonskiy, B V; Svenskaya, Yu I; Yashchenok, A М; Fattah, H A; Inozemtseva, O A; Tessarolo, F; Antolini, R; Gorin, D A

2014-06-01

An elegant route for hydroxyapatite (HA) particle synthesis via ionic exchange reaction is reported. Calcium carbonate particles (CaCO3) were recrystallized into HA beads in water solution with phosphate ions. The size of initial CaCO3 particles was controlled upon the synthesis by varying the amount of ethylene glycol (EG) in aqueous solution. The average size of HA beads ranged from 0.6±0.1 to 4.3±1.1μm. Silver nanoparticles were deposited on the surface of HA and CaCO3 particles via silver mirror reaction. Surface enhanced Raman scattering of silver functionalized beads was demonstrated by detecting Rhodamine B. CaCO3 and HA particles have a great potential for design of carrier which can provide diagnostic and therapeutic functions. Copyright © 2014 Elsevier B.V. All rights reserved.

Design, facile synthesis, and evaluation of novel spiro- and pyrazolo[1,5-c]quinazolines as cholinesterase inhibitors: Molecular docking and MM/GBSA studies.

PubMed

Gálvez, Jaime; Polo, Stivens; Insuasty, Braulio; Gutiérrez, Margarita; Cáceres, Daniela; Alzate-Morales, Jans H; De-la-Torre, Pedro; Quiroga, Jairo

2018-03-07

Given the wide spectrum of biological uses of pyrazolo[1,5-c]quinazoline and spiro-quinazoline derivatives as anticancer, anti-inflammatory analgesic agents, and their therapeutic applications in neurodegenerative disorders, it is compulsory to find easy, efficient, and simple methods to obtain and chemically diversify these families of compounds, thereby improving their biological applications. In this paper, we report the design and eco-friendly two-step synthesis of novel, fused spiro-pyrazolo[1,5-c]quinazoline derivatives as cholinesterase inhibitors. In addition, we studied their protein-ligand interactions via molecular docking and MM/GBSA calculations for a further rational design of more potent inhibitors. In first step, 2-(1H-pyrazol-5-yl)anilines were obtained through microwave (MW) assisted solvent-free/catalyst-free conditions and the second step involved the synthesis of the spiro-pyrazolo[1,5-c]quinazolines by a cyclocondensation reaction between 2-(1H-pyrazol-5-yl)anilines and cyclic ketones, or acetophenones, using stirring at room temperature. The compounds were obtained in high purity, good yields (50-97%), and at varying reaction times. The spiro-compounds were evaluated as acetylcholinesterase and butyrylcholinesterase inhibitors (AChEIs/BuChEIs) respectively, and the most potent compound exhibited a moderate AChE inhibitory activity (5f: IC 50  = 84 μM). Molecular docking studies indicated that the binding mode of the compound 5f share common characteristics with the galantamine/donepezil-AChE complexes. Moreover, free binding energy (ΔG) calculations showed a good agreement with the experimental biological activity values. Our theoretical results indicated that halogen bond interactions could be involved with differential potency of these compounds and provide a new starting point to design novel pyrazolo[1,5-c]quinazolines as new anti-Alzheimer agents. Copyright © 2018. Published by Elsevier Ltd.

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

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.

HA metabolism in skin homeostasis and inflammatory disease.

PubMed

Kavasi, Rafaela-Maria; Berdiaki, Aikaterini; Spyridaki, Ioanna; Corsini, Emanuela; Tsatsakis, Aristidis; Tzanakakis, George; Nikitovic, Dragana

2017-03-01

Hyaluronan (HA), an unsulfated glycosaminoglycan, is an important component of the complex extracellular matrix network which surrounds and supports cells in tissues. HA is detected in all vertebrate tissues, but the bulk of HA is produced and deposited in the skin. In this review we focus on the role of HA in skin-associated inflammatory disease and wound healing. Properties of HA are directly dependent on its molecular weight. Thus, high molecular weight HA (HMWHA) is deposited in normal tissues during homeostasis and promotes their stability whereas low molecular weight HA fragments (LMWHA), on the other hand, may arise from enzymatic or chemical activities. The degradation of HMWHA to LMWHA fragments, often leads to the generation of biologically active oligosaccharides with different properties and postulated functions in wound scar formation and inflammation. More detailed studies of HA involvement in skin-associated inflammatory disease may result in novel treatment modalities. Copyright © 2017 Elsevier Ltd. All rights reserved.

In situ synthesis of luminescent carbon nanoparticles toward target bioimaging.

PubMed

Sharker, Shazid Md; Kim, Sung Min; Lee, Jung Eun; Jeong, Ji Hoon; In, Insik; Lee, Kang Dea; Lee, Haeshin; Park, Sung Young

2015-03-12

This paper describes the in situ synthesis of single fluorescence carbon nanoparticles (FCNs) for target bioimaging applications derived from biocompatible hyaluronic acid (HA) without using common conjugation processes. FCNs formed via the dehydration of hyaluronic acid, which were obtained by carbonizing HA, and partially carbonized HA fluorescence carbon nanoparticles (HA-FCNs), formed by a lower degree of carbonization, show good aqueous solubility, small particle size (<20 nm) and different fluorescence intensities with a red shift. After confirming the cytotoxicity of HA-FCNs and FCNs, we carried out in vitro and in vivo bioimaging studies where HA-FCNs themselves functioned as single particle triggers in target imaging. The converted nanocrystal carbon particles from HA provide outstanding features for in vitro and in vivo new targeted delivery and diagnostic tools.

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

PubMed

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

2018-12-01

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

Cell wall mannoprotein of Candida albicans induces cell cycle alternation and inhibits apoptosis of HaCaT cells via NF-κB signal pathway.

PubMed

Han, Yang; Jiang, Hang-Hang; Zhang, Yu-Jing; Hao, Xing-Jia; Sun, Yu-Zhe; Qi, Rui-Qun; Chen, Hong-Duo; Gao, Xing-Hua

2017-10-01

Candida albicans (C. albicans) is a commensal organism in human and a well-known dimorphic opportunistic pathogenic fungus. Though plenty of researches on the pathogenesis of C. albicans have been performed, the mechanism is not fully understood. The cell wall components of C. albicans have been documented to play important roles in its pathogenic processes. To further study the infectious mechanism of C. albicans, we investigated the potential functional role of its cell wall mannoprotein in cell cycle and apoptosis of HaCaT cells. We found that mannoprotein could promote the transition of cell cycle from G1/G0 to S phase, in which Cyclin D1, CDK4 and p-Rb, the major regulators of the cell cycle progression, showed significant upregulation, and CDKN1A (cyclin dependent kinase inhibitor 1A (p21)) showed significant downregulation. Mannoprotein also could inhibit apoptosis of HaCaT cells, which was well associated with increased expression of BCL2 (Bcl-2). Moreover, mannoprotein could increase the phosphorylation levels of RELA (p65) and NFKBIA (IκBα), as the key factors of NF-κB signal pathway in HaCaT cells, suggesting the activation of NF-κB signal pathway. Additionally, a NF-κB specific inhibitor, PDTC, could rescue the effect of mannoprotein on cell cycle and apoptosis of HaCaT cells, which suggested that mannoprotein could activate NF-κB signal pathway to mediate cell cycle alternation and inhibit apoptosis. Copyright © 2017. Published by Elsevier Ltd.

Design of Monoamine Reuptake Inhibitors: SSRIs, SNRIs and NRIs

NASA Astrophysics Data System (ADS)

Whitlock, Gavin A.; Andrews, Mark D.; Brown, Alan D.; Fish, Paul V.; Stobie, Alan; Wakenhut, Florian

This review will detail the medicinal chemistry involved in the design, synthesis and discovery of selective serotonin, noradrenaline reuptake inhibitors and dual serotonin/noradrenaline reuptake inhibitors. In particular, this review will focus exclusively on series and compounds which have been disclosed within the medicinal chemistry literature between January 2000 and June 2008. Background information on previously disclosed clinical agents, such as atomoxetine, milnacipran and reboxetine, is included for comparison purposes with more recently disclosed agents.

The effect of the type of HA on the degradation of PLGA/HA composites.

PubMed

Naik, Ashutosh; Shepherd, David V; Shepherd, Jennifer H; Best, Serena M; Cameron, Ruth E

2017-01-01

The aim of this study is to explore the importance of the potentially competing effects of buffering effects of the calcium phosphate filler and particle-mediated water sorption on the degradation products of poly(d,l lactide-co-glycolide (50:50))(PLGA)/hydroxyapatite(HA) composites. Further the influence of type of HA on the mechanical properties of the composites was investigated. Phase pure HA was synthesised via a reaction between aqueous solutions of calcium hydroxide and orthophosphoric acid. The powder produced was either used as produced (uncalcined) or calcined in air or calcined in a humidified argon atmosphere. An in-vitro degradation study was carried out in phosphate buffered saline (PBS). The results obtained indicated that the degradation rate of the composite might be better understood if both the buffering effects and the rate of water sorption by the composites are considered. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization, Corrosion Resistance, and Cell Response of High-Velocity Flame-Sprayed HA and HA/TiO2 Coatings on 316L SS

NASA Astrophysics Data System (ADS)

Singh, Tejinder Pal; Singh, Harpreet; Singh, Hazoor

2012-09-01

The main aim of this study is to evaluate corrosion and biocompatibility behavior of thermal spray hydroxyapatite (HA) and hydroxyapatite/titania bond (HA/TiO2)-coated 316L stainless steel (316L SS). In HA/TiO2 coatings, TiO2 was used as a bond coat between HA top coat and 316L SS substrate. The coatings were characterized by x-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy, and corrosion resistance determined for the uncoated substrate and the two coatings. The biological behavior was investigated by the cell culture studies using osteosarcoma cell line KHOS-NP (R-970-5). The corrosion resistance of the steel was found to increase after the deposition of the HA and HA/TiO2 bond coatings. Both HA, as well as, HA/TiO2 coatings exhibit excellent bond strength of 49 and 47 MPa, respectively. The cell culture studies showed that HA-coated 316L SS specimens appeared more biocompatible than the uncoated and HA/TiO2-coated 316L SS specimens.

Selective pre-priming of HA-specific CD4 T cells restores immunological reactivity to HA on heterosubtypic influenza infection.

PubMed

Alam, Shabnam; Chan, Cory; Qiu, Xing; Shannon, Ian; White, Chantelle L; Sant, Andrea J; Nayak, Jennifer L

2017-01-01

A hallmark of the immune response to influenza is repeated encounters with proteins containing both genetically conserved and variable components. Therefore, the B and T cell repertoire is continually being remodeled, with competition between memory and naïve lymphocytes. Our previous work using a mouse model of secondary heterosubtypic influenza infection has shown that this competition results in a focusing of CD4 T cell response specificity towards internal virion proteins with a selective decrease in CD4 T cell reactivity to the novel HA epitopes. Strikingly, this shift in CD4 T cell specificity was associated with a diminished anti-HA antibody response. Here, we sought to determine whether the loss in HA-specific reactivity that occurs as a consequence of immunological memory could be reversed by selectively priming HA-specific CD4 T cells prior to secondary infection. Using a peptide-based priming strategy, we found that selective expansion of the anti-HA CD4 T cell memory repertoire enhanced HA-specific antibody production upon heterosubtypic infection. These results suggest that the potentially deleterious consequences of repeated exposure to conserved influenza internal virion proteins could be reversed by vaccination strategies that selectively arm the HA-specific CD4 T cell compartment. This could be a potentially useful pre-pandemic vaccination strategy to promote accelerated neutralizing antibody production on challenge with a pandemic influenza strain that contains few conserved HA epitopes.

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

Furylhydroquinones and miscellaneous compounds from the roots of Lithospermum erythrorhizon and their anti-inflammatory effect in HaCaT cells.

PubMed

Ahn, Jongmin; Chae, Hee-Sung; Chin, Young-Won; Kim, Jinwoong

2018-01-31

One new furylhydroquinone derivative (1) and seven known compounds (2-8) were isolated from the roots of Lithospermum erythrorhizon Sieb. et Zucc (Boraginaceae). The structure of 1 was elucidated by extensive spectroscopic methods using NMR and MS. The absolute configuration of shikonofuran J (1) was unambiguously determined by aid of comparison experimental ECD with predicted ECD spectra. All the isolates were tested for their inhibitory activities against IL-6 production in HaCaT cells stimulated by tumor necrosis factor (TNF)-α. It was found that gracicleistanthoside (5) and uridine (7) remarkably down-regulated the TNF-α-induced synthesis of interleukin-6 (IL-6), a pro-inflammatory cytokine associated with cutaneous inflammation, in HaCaT cells.

Simultaneous detection of assembly and disassembly of multivalent HA tag and anti-HA antibody in single in-capillary assay.

PubMed

Wang, Jianhao; Qin, Yuqin; Qin, Haifang; Liu, Li; Ding, Shumin; Teng, Yiwan; Ji, Junling; Qiu, Lin; Jiang, Pengju

2016-08-01

Herein, we have developed an in-capillary assay for simultaneous detection of the assembly and disassembly of the multivalent HA tag peptide and antibody. HA tag with hexahistidine at C terminus (YPYDVPDYAG4 H6 , termed YPYDH6 ) was conjugated with quantum dots (QDs) by metal-affinity force to form a multivalent HA tag (QD-YPYDH6 ). QD-YPYDH6 and monoclonal anti-HA antibody (anti-HA) were sequentially injected into the capillary. They were mixed and assembled inside the capillary. The reaction products were online discriminated and detected by fluorescence coupled capillary electrophoresis (CE-FL). For the in-capillary assay, the binding efficiency of the multivalent HA tag and antibody on was influenced by the molar ratio and injection time. Such novel assay could even give out the self-assembly kinetic constant of QDs and YPYDH6 as KD of 34.1 μM with n (binding cooperativeness) of 2.2 by Hill equation. More importantly, the simultaneous detection of the assembly and imidazole (Im) induced disassembly of the QD-YPYDH6 -anti-HA complex was achieved in a single in-capillary assay. Our study demonstrated a new method for the online detection of antigen-antibody interactions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mitogen-activated protein kinase kinase 1/extracellular signal-regulated kinase (MEK-1/ERK) inhibitors sensitize reduced glucocorticoid response mediated by TNFalpha in human epidermal keratinocytes (HaCaT).

PubMed

Onda, Kenji; Nagashima, Masahiro; Kawakubo, Yo; Inoue, Shota; Hirano, Toshihiko; Oka, Kitaro

2006-12-08

Glucocorticoids (GCs) are essential drugs administered topically or systematically for the treatment of autoimmune skin diseases such as pemphigus. However, a certain proportion of patients does not respond well to GCs. Although studies on the relationship between cytokines and GC insensitivity in local tissues have attracted attention recently, little is known about the underlying mechanism(s) for GC insensitivity in epidermal keratinocytes. Here, we report that tumor necrosis factor (TNF) alpha reduces GC-induced transactivation of endogenous genes as well as a reporter plasmid which contains GC responsive element (GRE) in human epidermal keratinocyte cells (HaCaT). The GC insensitivity by TNFalpha was not accompanied by changes in mRNA expressions of GR isoforms (alpha or beta). However, we observed that mitogen-activated protein kinase kinase-1/extracellular signal-regulated kinase (MEK-1/ERK) inhibitors (PD98059 and U0126) significantly sensitized the GC-induced transactivation of anti-inflammatory genes (glucocorticoid-induced leucine zipper (GILZ) and mitogen-activated protein kinase phosphatase (MKP)-1) and FK506 binding protein (FKBP) 51 gene in the presence of TNFalpha. Additionally, we observed that TNFalpha reduced prednisolone (PSL)-dependent nuclear translocation of GR, which was restored by pre-treatment of MEK-1 inhibitors. This is the first study demonstrating a role of the MEK-1/ERK cascade in TNFalpha-mediated GC insensitivity. Our data suggest that overexpression of TNFalpha leads to topical GC insensitivity by reducing GR nuclear translocation in keratinocytes, and our findings also suggest that inhibiting the MEK-1/ERK cascade may offer a therapeutic potential for increasing GC efficacy in epidermis where sufficient inflammatory suppression is required.

In situ synthesis of hydroxyapatite coating by laser cladding.

PubMed

Wang, D G; Chen, C Z; Ma, J; Zhang, G

2008-10-15

HA bioceramic coatings were synthesized on titanium substrate by laser cladding using cheap calcium carbonate and calcium hydrogen phosphate. The thermodynamic condition for synthesizing HA was calculated by software Matlab 5.0, the microstructure and phase analysis of laser clad HA bioceramic coatings were studied by electron probe microanalyser (EPMA), X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The theoretical results show that the Gibbs free enthalpy for the synthesis of HA phase is satisfied, and the presence of HA phase in the clad coatings was then further verified by XRD and the selected area diffraction patterns. When the laser power is 600W and the scanning speed is 3.5mm/s, the compact HA bioceramic coatings were obtained, which have cellular dendritic structure and consist of the phases of HA, alpha-Ca(2)P(2)O(7), CaO and CaTiO(3).

Effect of Water-Glass Coating on HA and HA-TCP Samples for MSCs Adhesion, Proliferation, and Differentiation.

PubMed

Bajpai, Indu; Kim, Duk Yeon; Kyong-Jin, Jung; Song, In-Hwan; Kim, Sukyoung

2016-01-01

Ca-P and silicon based materials have become very popular as bone tissue engineering materials. In this study, water-glass (also known as sodium silicate glass) was coated on sintered hydroxyapatite (HA) and HA-TCP (TCP stands for tricalcium phosphate) samples and subsequently heat-treated at 600°C for 2 hrs. X-rays diffraction showed the presence of β- and α-TCP phases along with HA in the HA-TCP samples. Samples without coating, with water-glass coating, and heat-treated after water-glass coating were used to observe the adhesion and proliferation response of bone marrow derived-mesenchymal stem cells (MSCs). Cell culture was carried out for 4 hrs, 1 day, and 7 days. Interestingly, all samples showed similar response for cell adhesion and proliferation up to 7-day culture but fibronectin, E-cadherin, and osteogenic differentiation related genes (osteocalcin and osteopontin) were significantly induced in heat-treated water-glass coated HA-TCP samples. A water-glass coating on Ca-P samples was not found to influence the cell proliferation response significantly but activated some extracellular matrix genes and induced osteogenic differentiation in the MSCs.

Non-genetic risk factors in haemophilia A inhibitor management - the danger theory and the use of animal models.

PubMed

Lövgren, K M; Søndergaard, H; Skov, S; Wiinberg, B

2016-09-01

In haemophilia A (HA) management, antidrug antibodies, or inhibitors, are a serious complication that renders factor VIII (FVIII) replacement therapy ineffective, increases morbidity and reduces quality of life for affected patients. Inhibitor development aetiology is multifactorial and covers both genetic and therapy related risk factors. Many therapy-related risk factors have proven difficult to confirm due to several confounding factors and the small study populations available. However, clinical studies indicate that e.g. on-demand treatment and surgery affect inhibitor development, and explanations for this association are being investigated. A potential explanation is the danger signal effect, where the immune response is activated by endogenous or exogenous danger or damage signals present at the time and site of FVIII administration. The danger theory explains how alarm signals from stressed, injured or dying cells can activate an immune reaction, without the involvement of foreign antigens. Bleeds, trauma, surgery or concomitant infection could be events initiating danger signalling in HA patients, resulting in an immune reaction towards administered FVIII that otherwise would pass unnoticed. This role of danger in HA inhibitor formation has previously been suggested, but a thorough discussion of this subject is lacking. The present review will discuss the potential role of danger signals in haemophilia and inhibitor development, with focus on treatment related risk factors with a suspected danger signal aetiology; on-demand treatment, treatment during major bleeds or surgery, and treatment during infection or vaccination. Clinical studies as well as animal experiments addressing these factors will be reviewed. © 2016 John Wiley & Sons Ltd.

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

PubMed

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

2012-10-01

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

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.

HaLT2- an enhanced lumber grading trainer

Treesearch

Powsiri Klinkhachorn; Charles Gatchell; Charles McMillin; Ravi Kothari; Dennis Yost

1992-01-01

This paper reports on HaLT2, an improved version of HaLT (Hardwood Lumber Traning Program)- a computer program that provides training in lumber grading. The newly added enhancements In HaLT2 will provide training for both novice and experienced hardwood lumber graders in accordance with National Hardwood Lumber Assodation (NHLA) rules. HaLT2 is more accurate, easier to...

Vanadium-induced apoptosis of HaCaT cells is mediated by c-fos and involves nuclear accumulation of clusterin

PubMed Central

Markopoulou, Soultana; Kontargiris, Evangelos; Batsi, Christina; Tzavaras, Theodore; Trougakos, Ioannis; Boothman, David A.; Gonos, Efstathios S.; Kolettas, Evangelos

2016-01-01

Vanadium exerts a variety of biological effects, including antiproliferative responses through activation of the respective signaling pathways and the generation of reactive oxygen species. As epidermal cells are exposed to environmental insults, human keratinocytes (HaCaT) were used to investigate the mechanism of the antiproliferative effects of vanadyl(IV) sulfate (VOSO4). Treatment of HaCaT cells with VOSO4 inhibited proliferation and induced apoptosis in a dose-dependent manner. Inhibition of proliferation was associated with downregulation of cyclins D1 and E, E2F1, and the cyclin-dependent kinase inhibitors p21Cip1/Waf1 and p27Kip1. Induction of apoptosis correlated with upregulation of the c-fos oncoprotein, changes in the expression of clusterin (CLU), an altered ratio of antiapoptotic to proapoptotic Bcl-2 protein family members, and poly(ADP-ribose) poly-merase-1 cleavage. Forced overexpression of c-fos induced apoptosis in HaCaT cells that correlated with secretory CLU downregulation and upregulation of nuclear CLU (nCLU), a pro-death protein. Overexpression of Bcl-2 protected HaCaT cells from vanadium-induced apoptosis, whereas secretory CLU overexpression offered no cytoprotection. In contrast, nCLU sensitized HaCaT cells to apoptosis. Our data suggest that vanadium-mediated apoptosis was promoted by c-fos, leading to alterations in CLU isoform processing and induction of the pro-death nCLU protein. PMID:19531052

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

PubMed

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

2016-11-22

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

Homology modeling study toward identifying structural properties in the HA2 B-loop that would influence the HA1 receptor-binding site.

PubMed

Cueno, Marni E; Imai, Kenichi; Shimizu, Kazufumi; Ochiai, Kuniyasu

2013-07-01

Influenza hemagglutinin (HA) consists of a fibrous globular stem (HA2) inserted into the viral membrane supporting a globular head (HA1). HA1 receptor-binding has been hypothesized to be structurally correlated to the HA2 B-loop, however, this was never fully understood. Here, we elucidated the structural relationship between the HA2 B-loop and the HA1 receptor-binding site (RBS). Throughout this study, we analyzed 2486 H1N1 HA homology models obtained from human, swine and avian strains during 1976-2012. Quality of all homology models were verified before further analyses. We established that amino acid residue 882 is putatively strain-conserved and differs in the human (K882), swine (H882) and avian (N882) strains. Moreover, we observed that the amino acid at residue 882 and, similarly, its orientation has the potential to influence the HA1 RBS diameter measurements which we hypothesize may consequentially affect influenza H1N1 viral infectivity, immune escape, transmissibility, and evolution. Copyright © 2013 Elsevier Inc. All rights reserved.

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.

HDAC inhibitors: a 2013-2017 patent survey.

PubMed

Faria Freitas, Micaela; Cuendet, Muriel; Bertrand, Philippe

2018-04-19

Zinc-dependent histone deacetylases (HDAC) inhibitors represent an important class of biologically active compounds with four of them approved by the FDA. A wide range of molecules has been reported for applications in several human diseases.Area covered: This review covers recent efforts in the synthesis and applications of HDAC inhibitors from 2013-2017.Expert opinion: HDAC inhibitors represent an important class of biologically active compounds for single or combination therapies. The current synthetic methodologies are oriented towards selective HDAC isoforms to achieve better therapeutic effects. Among the recent patents available, most of them focus on HDAC6 selective inhibitors. Beside this search for isoform selectivity, the quest for zinc binding groups with better pharmacokinetic properties and high potency against HDACs only motivates medicinal chemists, as well as the design of inhibitors targeting HDACs and at the same time another biological target. If the major applications are for anticancer activity, one can note the emerging applications in neurological or metabolic disorders or for the stimulation of the immune system.

A facile synthesis of lanost-8-en-3 beta-ol-24-one (24-ketolanosterol). An inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase.

PubMed

Parish, E J; Honda, H; Chitrakorn, S; Taylor, F R

1988-10-01

A facile chemical synthesis of lanost-8-en-3 beta-ol-24-one (24-ketolanosterol) is described. This compound was found to be a potent inhibitor of 3-hydroxy-3-methylglutaryl (HMG) CoA reductase activity in cultured mouse L cells. The synthetic scheme developed in this study utilizes commercial lanosterol as a starting material and involves selective hydroboration of the C-24 double bond followed by oxidation of the carbon-boron bond at C-24 by pyridinium chlorochromate (PCC).

Rapid hydrothermal flow synthesis and characterisation of carbonate- and silicate-substituted calcium phosphates

PubMed Central

Knowles, Jonathan C; Rehman, Ihtesham; Darr, Jawwad A

2013-01-01

A range of crystalline and nano-sized carbonate- and silicate-substituted hydroxyapatite has been successfully produced by using continuous hydrothermal flow synthesis technology. Ion-substituted calcium phosphates are better candidates for bone replacement applications (due to improved bioactivity) as compared to phase-pure hydroxyapatite. Urea was used as a carbonate source for synthesising phase pure carbonated hydroxyapatite (CO3-HA) with ≈5 wt% substituted carbonate content (sample 7.5CO3-HA) and it was found that a further increase in urea concentration in solution resulted in biphasic mixtures of carbonate-substituted hydroxyapatite and calcium carbonate. Transmission electron microscopy images revealed that the particle size of hydroxyapatite decreased with increasing urea concentration. Energy-dispersive X-ray spectroscopy result revealed a calcium deficient apatite with Ca:P molar ratio of 1.45 (±0.04) in sample 7.5CO3-HA. For silicate-substituted hydroxyapatite (SiO4-HA) silicon acetate was used as a silicate ion source. It was observed that a substitution threshold of ∼1.1 wt% exists for synthesis of SiO4-HA in the continuous hydrothermal flow synthesis system, which could be due to the decreasing yields with progressive increase in silicon acetate concentration. All the as-precipitated powders (without any additional heat treatments) were analysed using techniques including Transmission electron microscopy, X-ray powder diffraction, Differential scanning calorimetry, Thermogravimetric analysis, Raman spectroscopy and Fourier transform infrared spectroscopy. PMID:22983020

Hyaluronic Acid Decreases Lipid Synthesis in Sebaceous Glands.

PubMed

Jung, Yu Ra; Hwang, Chul; Ha, Jeong-Min; Choi, Dae-Kyoung; Sohn, Kyung-Cheol; Lee, Young; Seo, Young-Joon; Lee, Young-Ho; Kim, Chang-Deok; Lee, Jeung-Hoon; Im, Myung

2017-06-01

Hyaluronic acid (HA) is the major glycosaminoglycan in the extracellular matrix and has been implicated in several functions in skin cells. However, evidence is lacking regarding the HA signaling in sebaceous glands, and its potential role needs to be clarified. We investigated the role of HA in lipid production in sebaceous glands in an experimental study of human sebocytes followed by a clinical study. We first examined the effects of HA on sebaceous glands in hamsters and intradermal injection of HA into hamster auricles decreased both the size of sebaceous glands and the level of lipid production. We demonstrated that human skin sebaceous glands in vivo and sebocytes in vitro express CD44 (HA binding receptor) and that HA downregulates lipid synthesis in a dose-dependent manner. To evaluate the clinical relevance of HA in human skin, 20 oily participants were included in a double-blind, placebo-controlled, split-face study, and the HA-treated side showed a significant decrease in sebum production. The results of this study indicate that HA plays a functional role in human sebaceous gland biology and HA signaling is an effective candidate in the management of disorders in which sebum production is increased. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Registration of two double rust resistant germplasms, HA-R12 and HA-R13 for confection sunflower

USDA-ARS?s Scientific Manuscript database

The confection sunflower (Helianthus annuus L.) germplasms HA-R12 (Reg. No. ______, PI 673104) and HA-R13 (Reg. No. ______, PI 673105) were developed by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station, and released in Jul...

Synergistic interaction of platelet derived growth factor (PDGF) with the surface of PLLA/Col/HA and PLLA/HA scaffolds produces rapid osteogenic differentiation.

PubMed

Raghavendran, Hanumantha Rao Balaji; Mohan, Saktiswaren; Genasan, Krishnamurithy; Murali, Malliga Raman; Naveen, Sangeetha Vasudevaraj; Talebian, Sepehr; McKean, Robert; Kamarul, Tunku

2016-03-01

Scaffolds with structural features similar to the extracellular matrix stimulate rapid osteogenic differentiation in favorable microenvironment and with growth factor supplementation. In this study, the osteogenic potential of electrospun poly-l-lactide/hydroxyapatite/collagen (PLLA/Col/HA, PLLA/HA and PLLA/Col) scaffolds were tested in vitro with the supplementation of platelet derived growth factor-BB (PDGF-BB). Cell attachment and topography, mineralization, extracellular matrix protein localization, and gene expression of the human mesenchymal stromal cells were compared between the fibrous scaffolds PLLA/Col/HA, PLLA/Col, and PLLA/HA. The levels of osteocalcin, calcium, and mineralization were significantly greater in the PLLA/Col/HA and PLLA/HA compared with PLLA/Col. High expression of fibronectin, intracellular adhesion molecule, cadherin, and collagen 1 (Col1) suggests that PLLA/Col/HA and PLLA/HA scaffolds had superior osteoinductivity than PLLA/Col. Additionally, osteopontin, osteocalcin, osterix, Runt-related transcription factor 2 (Runx2), and bone morphogenic protein (BMP2) expression were higher in PLLA/Col/HA and PLLA/HA compared with PLLA/Col. In comparison with PLLA/Col, the PLLA/Col/HA and PLLA/HA scaffolds presented a significant upregulation of the genes Runx2, Col 1, Integrin, osteonectin (ON), bone gamma-carboxyglutamic acid-containing protein (BGALP), osteopontin (OPN), and BMP2. The upregulation of these genes was further increased with PDGF-BB supplementation. These results show that PDGF-BB acts synergistically with PLLA/Col/HA and PLLA/HA to enhance the osteogenic differentiation potential. Therefore, this combination can be used for the rapid expansion of bone marrow stromal cells into bone-forming cells for tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

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

Molecular Modeling, de novo Design and Synthesis of a Novel, Extracellular Binding Fibroblast Growth Factor Receptor 2 Inhibitor Alofanib (RPT835).

PubMed

Tsimafeyeu, Ilya; Daeyaert, Frits; Joos, Jean-Baptiste; Aken, Koen V; Ludes-Meyers, John; Byakhov, Mikhail; Tjulandin, Sergei

2016-01-01

Fibroblast growth factor (FGF) receptors (FGFRs) play a key role in tumor growth and angiogenesis. The present report describes our search for an extracellularly binding FGFR inhibitor using a combined molecular modeling and de novo design strategy. Based upon crystal structures of the receptor with its native ligand and knowledge of inhibiting peptides, we have developed a computational protocol that predicts the putative binding of a molecule to the extracellular domains of the receptor. This protocol, or scoring function, was used in combination with the de novo synthesis program 'SYNOPSIS' to generate high scoring and synthetically accessible compounds. Eight compounds belonging to 3 separate chemical classes were synthesized. One of these compounds, alofanib (RPT835), was found to be an effective inhibitor of the FGF/FGFR2 pathway. The preclinical in vitro data support an allosteric inhibition mechanism of RPT835. RPT835 potently inhibited growth of KATO III gastric cancer cells expressing FGFR2, with GI50 value of 10 nmol/L. These results provide strong rationale for the evaluation of compound in advanced cancers.

Design and Synthesis of Highly Potent HIV-1 Protease Inhibitors Containing Tricyclic Fused Ring Systems as Novel P2 Ligands: Structure-Activity Studies, Biological and X-ray Structural Analysis.

PubMed

Ghosh, Arun K; R Nyalapatla, Prasanth; Kovela, Satish; Rao, Kalapala Venkateswara; Brindisi, Margherita; Osswald, Heather L; Amano, Masayuki; Aoki, Manabu; Agniswamy, Johnson; Wang, Yuan-Fang; Weber, Irene T; Mitsuya, Hiroaki

2018-05-24

The design, synthesis, and biological evaluation of a new class of HIV-1 protease inhibitors containing stereochemically defined fused tricyclic polyethers as the P2 ligands and a variety of sulfonamide derivatives as the P2' ligands are described. A number of ring sizes and various substituent effects were investigated to enhance the ligand-backbone interactions in the protease active site. Inhibitors 5c and 5d containing this unprecedented fused 6-5-5 ring system as the P2 ligand, an aminobenzothiazole as the P2' ligand, and a difluorophenylmethyl as the P1 ligand exhibited exceptional enzyme inhibitory potency and maintained excellent antiviral activity against a panel of highly multidrug-resistant HIV-1 variants. The umbrella-like P2 ligand for these inhibitors has been synthesized efficiently in an optically active form using a Pauson-Khand cyclization reaction as the key step. The racemic alcohols were resolved efficiently using a lipase catalyzed enzymatic resolution. Two high resolution X-ray structures of inhibitor-bound HIV-1 protease revealed extensive interactions with the backbone atoms of HIV-1 protease and provided molecular insight into the binding properties of these new inhibitors.

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.

Progress of small molecular inhibitors in the development of anti-influenza virus agents

PubMed Central

Wu, Xiaoai; Wu, Xiuli; Sun, Qizheng; Zhang, Chunhui; Yang, Shengyong; Li, Lin; Jia, Zhiyun

2017-01-01

The influenza pandemic is a major threat to human health, and highly aggressive strains such as H1N1, H5N1 and H7N9 have emphasized the need for therapeutic strategies to combat these pathogens. Influenza anti-viral agents, especially active small molecular inhibitors play important roles in controlling pandemics while vaccines are developed. Currently, only a few drugs, which function as influenza neuraminidase (NA) inhibitors and M2 ion channel protein inhibitors, are approved in clinical. However, the acquired resistance against current anti-influenza drugs and the emerging mutations of influenza virus itself remain the major challenging unmet medical needs for influenza treatment. It is highly desirable to identify novel anti-influenza agents. This paper reviews the progress of small molecular inhibitors act as antiviral agents, which include hemagglutinin (HA) inhibitors, RNA-dependent RNA polymerase (RdRp) inhibitors, NA inhibitors and M2 ion channel protein inhibitors etc. Moreover, we also summarize new, recently reported potential targets and discuss strategies for the development of new anti-influenza virus drugs. PMID:28382157

Extract from Periostracum cicadae Inhibits Oxidative Stress and Inflammation Induced by Ultraviolet B Irradiation on HaCaT Keratinocytes

PubMed Central

Tsen, Jen-Horng; Yen, Hsuan; Yang, Ting-Ya

2017-01-01

Periostracum cicadae is widely used for the treatment of skin diseases such as eczema, pruritus, and itching. The current study sought to evaluate the effect of P. cicadae extract on ultraviolet B (UVB) irradiation and identify the mechanisms involved. Photodamage-protective activity of P. cicadae extracts against oxidative challenge was screened using HaCaT keratinocytes. P. cicadae extracts did not affect cell viability but decreased reactive oxygen species (ROS) production. The extract attenuates the expression of interleukin-6 (IL-6), matrix metalloproteinase-2 (MMP-2), and MMP-9 in UVB-treated HaCaT cells. Also, P. cicadae abrogated UVB-induced activation of NF-κB, p53, and activator protein-1 (AP-1). The downmodulation of IL-6 by P. cicadae was inhibited by the p38 inhibitor (SB203580) or JNK inhibitor (SP600125). Moreover, the extract attenuated the expression of NF-κB and induced thrombomodulin in keratinocytes and thereby effectively downregulated inflammatory responses in the skin. The nuclear accumulation and expression of NF-E2-related factor (Nrf2) were increased by P. cicadae treatment. Furthermore, treatment with P. cicadae remarkably ameliorated the skin's structural damage induced by irradiation. This study demonstrates that P. cicadae may protect skin cells against oxidative insult by modulating ROS concentration, IL-6, MMPs generation, antioxidant enzymes activity, and cell signaling pathways. PMID:28465707

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.

Mitogen-activated protein kinase kinase 1/extracellular signal-regulated kinase (MEK-1/ERK) inhibitors sensitize reduced glucocorticoid response mediated by TNF{alpha} in human epidermal keratinocytes (HaCaT)

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

Onda, Kenji; Nagashima, Masahiro; Kawakubo, Yo

2006-12-08

Glucocorticoids (GCs) are essential drugs administered topically or systematically for the treatment of autoimmune skin diseases such as pemphigus. However, a certain proportion of patients does not respond well to GCs. Although studies on the relationship between cytokines and GC insensitivity in local tissues have attracted attention recently, little is known about the underlying mechanism(s) for GC insensitivity in epidermal keratinocytes. Here, we report that tumor necrosis factor (TNF) {alpha} reduces GC-induced transactivation of endogenous genes as well as a reporter plasmid which contains GC responsive element (GRE) in human epidermal keratinocyte cells (HaCaT). The GC insensitivity by TNF{alpha} wasmore » not accompanied by changes in mRNA expressions of GR isoforms ({alpha} or {beta}). However, we observed that mitogen-activated protein kinase kinase-1/extracellular signal-regulated kinase (MEK-1/ERK) inhibitors (PD98059 and U0126) significantly sensitized the GC-induced transactivation of anti-inflammatory genes (glucocorticoid-induced leucine zipper (GILZ) and mitogen-activated protein kinase phosphatase (MKP)-1) and FK506 binding protein (FKBP) 51 gene in the presence of TNF{alpha}. Additionally, we observed that TNF{alpha} reduced prednisolone (PSL)-dependent nuclear translocation of GR, which was restored by pre-treatment of MEK-1 inhibitors. This is the first study demonstrating a role of the MEK-1/ERK cascade in TNF{alpha}-mediated GC insensitivity. Our data suggest that overexpression of TNF{alpha} leads to topical GC insensitivity by reducing GR nuclear translocation in keratinocytes, and our findings also suggest that inhibiting the MEK-1/ERK cascade may offer a therapeutic potential for increasing GC efficacy in epidermis where sufficient inflammatory suppression is required.« less

Hydrocortisone effect on hyaluronate synthesis in a self-assembled human dermal equivalent.

PubMed

Deshpande, Madhura; Papp, Suzanne; Schaffer, Lana; Pouyani, Tara

2016-10-01

Human dermal matrix is a 'self-assembled' dermal equivalent containing large amounts of the glycosaminoglycan hyaluronic acid (hyaluronate, hyaluronan, HA). We sought to investigate the actions of the hormone hydrocortisone on hyaluronate synthesis in the human dermal matrix. To this end, human dermal fibroblasts were cultured under serum-free conditions, and in the absence of a three-dimensional matrix, in the presence of varying amounts of hydrocortisone. The resultant human dermal matrices were characterized. We report that low concentrations of hydrocortisone enhance hyaluronate synthesis in the human dermal equivalent and higher concentrations cause inhibition of hyaluronate synthesis. Other glycosaminoglycan (chondroitin sulphate) synthesis is not affected by changing hydrocortisone concentrations up to 500× (200 µg/ml) of the base value. In order to gain preliminary insight into the molecular mechanism of hyaluronate inhibition, a differential gene array analysis was conducted of human dermal matrix grown in the presence of 200 µg/ml hydrocortisone and in a physiological concentration (0.4 µg/ml, normal conditions). The results of these experiments demonstrate the differential expression of 43 genes in the 500× (200 µg/ml) hydrocortisone construct as compared to the construct grown under normal conditions (0.4 µg/ml hydrocortisone). These preliminary experiments suggest that hydrocortisone at higher concentrations may exert its inhibitory effect on hyaluronate synthesis early in the glycolytic pathway, leading to HA biosynthesis by downregulation of phosphoglucomutase and glucose phosphate isomerase, possibly leading to depletion of the cellular pool of UDP-sugar precursors necessary for HA synthesis. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.

Antibacterial Property of Cold-Sprayed HA-Ag/PEEK Coating

NASA Astrophysics Data System (ADS)

Sanpo, Noppakun; Tan, Meng Lu; Cheang, Philip; Khor, K. A.

2009-03-01

The antibacterial behavior of HA-Ag (silver-doped hydroxyapatite) nanopowder and their composite coatings were investigated against Escherichia coli (DH5α). HA-Ag nanopowder and PEEK (poly-ether-ether-ketone)-based HA-Ag composite powders were synthesized using in-house powder processing techniques. Bacteria culture assay of HA-Ag nanopowder and their composite powders displayed excellent bacteriostatic activity against E. coli. The antibacterial activity increased with increasing concentration of HA-Ag nanoparticle in these composite powders. These nanocomposite powders were subsequently used as feedstock to generate antibacterial coatings via cold spray technology. The ratios of HA-Ag to PEEK in their composite powders were 80:20, 60:40, 40:60, and 20:80 (wt.%). Microstructural characterization and phase analysis of feedstock powders and as-deposited coatings were carried out using FESEM/EDX and XRD. Antibacterial nanocomposite HA-Ag/PEEK coatings were successfully deposited using cold spraying parameters of 11-12 bars at preheated air temperature between 150 and 160 °C. These as-sprayed coatings of HA-Ag/PEEK composite powders comprising varying HA-Ag and PEEK ratios retained their inherent antibacterial property as verified from bacterial assay. The results indicated that the antibacterial activity increased with increasing HA-Ag nanopowder concentration in the composite powder feedstock and cold-sprayed coating.

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.

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.

Role of UDP-N-Acetylglucosamine (GlcNAc) and O-GlcNAcylation of Hyaluronan Synthase 2 in the Control of Chondroitin Sulfate and Hyaluronan Synthesis*

PubMed Central

Vigetti, Davide; Deleonibus, Sara; Moretto, Paola; Karousou, Eugenia; Viola, Manuela; Bartolini, Barbara; Hascall, Vincent C.; Tammi, Markku; De Luca, Giancarlo; Passi, Alberto

2012-01-01

Hyaluronan (HA) is a glycosaminoglycan present in most tissue microenvironments that can modulate many cell behaviors, including proliferation, migration, and adhesive proprieties. In contrast with other glycosaminoglycans, which are synthesized in the Golgi, HA is synthesized at the plasma membrane by one or more of the three HA synthases (HAS1–3), which use cytoplasmic UDP-glucuronic acid and UDP-N-acetylglucosamine as substrates. Previous studies revealed the importance of UDP-sugars for regulating HA synthesis. Therefore, we analyzed the effect of UDP-GlcNAc availability and protein glycosylation with O-linked N-acetylglucosamine (O-GlcNAcylation) on HA and chondroitin sulfate synthesis in primary human aortic smooth muscle cells. Glucosamine treatment, which increases UDP-GlcNAc availability and protein O-GlcNAcylation, increased synthesis of both HA and chondroitin sulfate. However, increasing O-GlcNAcylation by stimulation with O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate without a concomitant increase of UDP-GlcNAc increased only HA synthesis. We found that HAS2, the main synthase in aortic smooth muscle cells, can be O-GlcNAcylated on serine 221, which strongly increased its activity and its stability (t½ >5 h versus ∼17 min without O-GlcNAcylation). S221A mutation prevented HAS2 O-GlcNAcylation, which maintained the rapid turnover rate even in the presence of GlcN and increased UDP-GlcNAc. These findings could explain the elevated matrix HA observed in diabetic vessels that, in turn, could mediate cell dedifferentiation processes critical in vascular pathologies. PMID:22887999

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.

Anti-AIDS agents 81. Design, synthesis, and structure-activity relationship study of betulinic acid and moronic acid derivatives as potent HIV maturation inhibitors.

PubMed

Qian, Keduo; Kuo, Reen-Yun; Chen, Chin-Ho; Huang, Li; Morris-Natschke, Susan L; Lee, Kuo-Hsiung

2010-04-22

In our continuing study of triterpene derivatives as potent anti-HIV agents, different C-3 conformationally restricted betulinic acid (BA, 1) derivatives were designed and synthesized in order to explore the conformational space of the C-3 pharmacophore. 3-O-Monomethylsuccinyl-betulinic acid (MSB) analogues were also designed to better understand the contribution of the C-3' dimethyl group of bevirimat (2), the first-in-class HIV maturation inhibitor, which is currently in phase IIb clinical trials. In addition, another triterpene skeleton, moronic acid (MA, 3), was also employed to study the influence of the backbone and the C-3 modification toward the anti-HIV activity of this compound class. This study enabled us to better understand the structure-activity relationships (SAR) of triterpene-derived anti-HIV agents and led to the design and synthesis of compound 12 (EC(50): 0.0006 microM), which displayed slightly better activity than 2 as a HIV-1 maturation inhibitor.

Synthesis and biological evaluation of glycogen synthase kinase 3 (GSK-3) inhibitors: an fast and atom efficient access to 1-aryl-3-benzylureas.

PubMed

Monte, Fabio Lo; Kramer, Thomas; Boländer, Alexander; Plotkin, Batya; Eldar-Finkelman, Hagit; Fuertes, Ana; Dominguez, Juan; Schmidt, Boris

2011-09-15

The glycogen synthase kinase 3 (GSK-3) is implicated in multiple cellular processes and has been linked to the pathogenesis of Alzheimer's disease (AD). In the course of our research topic we synthesized a library of potent GSK-3 inhibitors. We utilized the urea scaffold present in the potent and highly selective GSK-3 inhibitor AR-A014418 (AstraZeneca). This moiety suits both (a) a convergent approach utilizing readily accessible building blocks and (b) a divergent approach based on a microwave heating assisted Suzuki coupling. We established a chromatography-free purification method to generate products with sufficient purity for the biological assays. The structure-activity relationship of the library provided the rationale for the synthesis of the benzothiazolylurea 66 (IC(50)=140 nM) and the pyridylurea 62 (IC(50)=98 nM), which displayed two to threefold enhanced activity versus the reference compound 18 (AR-A014418: IC(50)=330 nM) in our assays. Copyright © 2011. Published by Elsevier Ltd.

ATP Synthesis in the Extremely Halophilic Bacteria

NASA Technical Reports Server (NTRS)

Hochstein, Lawrence I.; Morrison, David (Technical Monitor)

1994-01-01

The proton-translocating ATPases are multimeric enzymes that carry out a multitude of essential functions. Their origin and evolution represent a seminal event in the early evolution of life. Amino acid sequences of the two largest subunits from archaeal ATPases (A-ATPases), vacuolar ATPases (V-ATPases), and FOF1-ATP syntheses (FATPases) suggest these ATPases evolved from an ancestral vacuolar-like ATP syntheses. A necessary consequence of this notion is that the A-ATPases are ATP syntheses. With the possible exception of the A-ATPase from Halobacterium salinarium. no A-ATPase has been demonstrated to synthesize ATP. The evidence for this case is dubious since ATP synthesis occurs only when conditions are distinctively unphysiological. We demonstrated that ATP synthesis in H.saccharovorum is inconsistent with the operation of an A-type ATPase. In order to determine if this phenomenon was unique to H. saccharovorum, ATP synthesis was examined in various extremely halophilic bacteria with the goal of ascertaining if it resembled what occurred in a. saccharovorum, or was consistent with the operation of an A-type ATPase. A-, V-, and F-type ATPases respond singularly to certain inhibitors. Therefore, the effect of these inhibitors on ATP synthesis in several extreme halophiles was determined. Inhibitors that either blocked or collapsed proton-gradients inhibited the steady state synthesis of ATP thus verifying that synthesis took place at the expense of a proton gradient. Azide, an inhibitor of F-ATPases inhibited ATP synthesis. Since the arginine-dependent synthesis of ATP, which occurs by way of substrate-level phosphorylation, was unaffected by azide, it was unlikely that azide acted as an "uncoupler." N -ethylmaleimide and nitrate, which inhibit V- and A-ATPases, either did not inhibit ATP synthesis or resulted in higher steady-state levels of ATP. These results suggest there are two types of proton-motive ATPases in the extreme halophiles (and presumably in other

Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

NASA Technical Reports Server (NTRS)

Pearman, Benjamin Pieter; Li, Wenyan; Buhrow, Jerry; Zhang, Xuejun; Surma, Jan; Fitzpatrick, Lilly; Montgomery, Eliza; Calle, Luz Marina

2014-01-01

Research efforts are under way to replace current corrosion inhibitors with more environmentally friendly alternatives. However, problems with corrosion inhibition efficiency, coating compatibility and solubility have hindered the use of many of these materials as simple pigment additives.This paper will present technical details on how the Corrosion Technology Lab at NASAs Kennedy Space Center (KSC) has addressed these issues by encapsulating environmentally friendly inhibitors into organic and inorganic microparticles and microcapsules. The synthetic process for polymer particles was characterized and post-synthesis analysis was performed to determine the interactions between the inhibitors and the encapsulation material. The pH-controlled release of inhibitors from various particle formulations in aqueous base was monitored and compared to both electrochemical and salt immersion accelerated corrosion experiment. Furthermore, synergistic corrosion inhibition effects observed during the corrosion testing of several inhibitor combinations will be presented.

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.

Biomolecule-loaded chitosan nanoparticles induce apoptosis and molecular changes in cancer cell line (SiHa).

PubMed

Sujima Anbu, Anbu; Velmurugan, Palanivel; Lee, Jeong-Ho; Oh, Byung-Taek; Venkatachalam, Perumal

2016-07-01

The present study reports on the synthesis of chitosan nanoparticles (CNPs) using methanol extracts of Gymnema sylvestre (GS) leaves and Cinnamomum zeylanicum (CZ) bark. Biomolecule-loaded nanoparticles induced apoptosis in a human cervical cancer (SiHa) cell line, and experiments were carried out to elucidate the underlying molecular mechanisms. FT-IR and XRD showed possible functional groups of the biomolecules and the crystalline nature of CNPs, respectively. Transmission electron microscopy images revealed that synthesized GSCNPs and CZCNPs had a smooth spherical shape with average sizes of about 58-80 and 60-120nm, respectively. Dynamic light scattering studies indicated that both GSCNPs and CZCNs were structurally stable with homogenous and heterogeneous natures, respectively. Furthermore, synthesized GSCNPs and CZCNPs exhibited dose-dependent cytotoxicity against the SiHa cancer cell line, with inhibitory concentration (IC50) values of 102.17μg/ml, 87.75μg/ml, 132.74μg/ml and 90.35μg/ml for GS leaf extract, GSCNPs, CZBE and CZCNPs, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Highly stretchable HA/SA hydrogels for tissue engineering.

PubMed

Zhu, Chengcheng; Yang, Rui; Hua, Xiaobin; Chen, Hong; Xu, Jumei; Wu, Rile; Cen, Lian

2018-04-01

A highly stretchable hyaluronic acid (HA)/sodium alginate (SA) hydrogel was developed in this study based on an interpenetrating polymer network. HA/SA hydrogels were prepared by mixing two polysaccharides followed by covalent crosslinking via epoxy groups on HA molecules and ionic crosslinking via divalent ions on SA chains sequentially. The effect of HA/SA ratio on the pore size and distribution, swelling ratio, elongation and rheological properties as well as protein loading and release properties of HA/SA hydrogels was explored. Moreover, a surface modification method, layer-by-layer (LBL) assembly technique, was applied to modify the hydrogel to evaluate the hydrogel's tenability in varying biological performance. It was then shown that the hydrogels had the pore sizes ranging from 100 to 50 μm. With the increase in SA content of the resulting hydrogels, the pore size, swelling ratio, and storage modulus (G') and loss modulus (G″) of the hydrogel all decreased, whereas the in vitro bulk weight loss was fastened. Moreover, elongation at break (EB) value increased first, reached a peak value and then decreased, that is HA8/SA1 (HA:SA = 8:1) had the highest EB value of 417%. This hydrogel could retain 33.2% of the pre-loaded protein even after 72 h, which could be further attenuated when LBL was used to shell the hydrogel. The growth of fibroblasts on HA8/SA1 hydrogel gave preliminary assessment on its suitability as a cellular carrier, while the LBL modified HA8/SA1 hydrogel also favored the anchoring of keratinocytes, further enhancing its cell carrier role for tissue regeneration, especially skin engineering.

Glycosylation of Residue 141 of Subtype H7 Influenza A Hemagglutinin (HA) Affects HA-Pseudovirus Infectivity and Sensitivity to Site A Neutralizing Antibodies.

PubMed

Alvarado-Facundo, Esmeralda; Vassell, Russell; Schmeisser, Falko; Weir, Jerry P; Weiss, Carol D; Wang, Wei

2016-01-01

Human infections with H7 subtype influenza virus have been reported, including an H7N7 outbreak in Netherlands in 2003 and H7N9 infections in China in 2013. Previously, we reported murine monoclonal antibodies (mAbs) that recognize the antigenic site A of H7 hemagglutinin (HA). To better understand protective immunity of H7 vaccines and vaccine candidate selection, we used these mAbs to assess the antigenic relatedness among two H7 HA isolated from past human infections and determine residues that affect susceptibility to neutralization. We found that these mAbs neutralize pseudoviruses bearing HA of A/Shanghai/02/2013(H7N9), but not A/Netherlands/219/2003(H7N7). Glycosylation of the asparagine residue at position 141 (N141) (N133, H3 HA numbering) in the HA of A/Netherlands/219/2003 HA is responsible for this resistance, and it affects the infectivity of HA-pseudoviruses. The presence of threonine at position 143 (T135, H3 HA numbering) in the HA of A/Netherlands/219/2003, rather than an alanine found in the HA of A/Shanghai/02/2013(H7N9), accounts for these differences. These results demonstrate a key role for glycosylation of residue N141 in affecting H7 influenza HA-mediated entry and sensitivity to neutralizing antibodies, which have implications for candidate vaccine design.

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.

Synthetic (p)ppGpp Analogue Is an Inhibitor of Stringent Response in Mycobacteria

PubMed Central

Syal, Kirtimaan; Flentie, Kelly; Bhardwaj, Neerupma; Maiti, Krishnagopal; Jayaraman, Narayanaswamy; Stallings, Christina L.

2017-01-01

ABSTRACT Bacteria elicit an adaptive response against hostile conditions such as starvation and other kinds of stresses. Their ability to survive such conditions depends, in part, on stringent response pathways. (p)ppGpp, considered to be the master regulator of the stringent response, is a novel target for inhibiting the survival of bacteria. In mycobacteria, the (p)ppGpp synthetase activity of bifunctional Rel is critical for stress response and persistence inside a host. Our aim was to design an inhibitor of (p)ppGpp synthesis, monitor its efficiency using enzyme kinetics, and assess its phenotypic effects in mycobacteria. As such, new sets of inhibitors targeting (p)ppGpp synthesis were synthesized and characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. We observed significant inhibition of (p)ppGpp synthesis by RelMsm in the presence of designed inhibitors in a dose-dependent manner, which we further confirmed by monitoring the enzyme kinetics. The Rel enzyme inhibitor binding kinetics were investigated by isothermal titration calorimetry. Subsequently, the effects of the compounds on long-term persistence, biofilm formation, and biofilm disruption were assayed in Mycobacterium smegmatis, where inhibition in each case was observed. In vivo, (p)ppGpp levels were found to be downregulated in M. smegmatis treated with the synthetic inhibitors. The compounds reported here also inhibited biofilm formation by the pathogen Mycobacterium tuberculosis. The compounds were tested for toxicity by using an MTT assay with H460 cells and a hemolysis assay with human red blood cells, for which they were found to be nontoxic. The permeability of compounds across the cell membrane of human lung epithelial cells was also confirmed by mass spectrometry. PMID:28396544

The influence of DNA inhibitor synthesis on the induction and repair of double-strand DNA breaks in human lymphocytes under action of radiation with a different linear energy transfer

NASA Astrophysics Data System (ADS)

Boreyko, A. V.; Chausov, V. N.; Krasavin, E. A.; Ravnachka, I.; Stukova, S. I.

2011-07-01

The influence that inhibitors of repair and replicative DNA synthesis, 1-β-D-arabinofuranosyl-cytosine and hydroxyurea, have on the formation and repair kinetics of double-strand breaks (DSBs) in peripheral human blood lymphocytes under the influence of radiation with a different linear energy transfer (LET) (gamma quanta and accelerated heavy ions) is studied. It is demonstrated that lithium and boron ions with LETs of 20 and 40 keV/μm, respectively, possess higher biological effectiveness with respect to the DNA DSB induction criterion. The value of the relative biological effectiveness of accelerated lithium and boron ions is 1.5 ± 0.1 and 1.6 ± 0.1, respectively. It is found that, upon cell irradiation by gamma quanta in the absence of inhibitors, efficient DNA DSB repair is observed during incubation. Under the conditions of cell incubation and in the presence of inhibitors, some growth in the number of DNA DSBs, rather than a reduction, is observed after 5-h incubation. In the case of the action of accelerated boron ions (as well as gamma quanta), under normal conditions, the efficient repair of induced DNA lesions takes place. Unlike the action of gamma quanta, in the case of cell incubation in the presence of radiomodifiers, the number of induced DNA DSBs falls. These results may testify to the fact that the repair of double-strand DNS breaks takes place under the action of ionizing radiation with a different LET on mammalian cells in the presence of DNA synthesis inhibitors Ara-C and HU. It is concluded that, for cells subject to gamma irradiation, no DNA DSB repair is observed due to the large contribution of single-strand incision DNA breaks formed in the postradiation period in the course of excision nucleotide repair.

HA Antibody-Mediated FcγRIIIa Activity Is Both Dependent on FcR Engagement and Interactions between HA and Sialic Acids.

PubMed

Cox, Freek; Kwaks, Ted; Brandenburg, Boerries; Koldijk, Martin H; Klaren, Vincent; Smal, Bastiaan; Korse, Hans J W M; Geelen, Eric; Tettero, Lisanne; Zuijdgeest, David; Stoop, Esther J M; Saeland, Eirikur; Vogels, Ronald; Friesen, Robert H E; Koudstaal, Wouter; Goudsmit, Jaap

2016-01-01

Interactions with receptors for the Fc region of IgG (FcγRs) have been shown to contribute to the in vivo protection against influenza A viruses provided by broadly neutralizing antibodies (bnAbs) that bind to the viral hemagglutinin (HA) stem. In particular, Fc-mediated antibody-dependent cellular cytotoxicity (ADCC) has been shown to contribute to protection by stem-binding bnAbs. Fc-mediated effector functions appear not to contribute to protection provided by strain-specific HA head-binding antibodies. We used a panel of anti-stem and anti-head influenza A and B monoclonal antibodies with identical human IgG1 Fc domains and investigated their ability to mediate ADCC-associated FcγRIIIa activation. Antibodies which do not interfere with sialic acid binding of HA can mediate FcγRIIIa activation. However, the FcγRIIIa activation was inhibited when a mutant HA, unable to bind sialic acids, was used. Antibodies which block sialic acid receptor interactions of HA interfered with FcγRIIIa activation. The inhibition of FcγRIIIa activation by HA head-binding and sialic acid receptor-blocking antibodies was confirmed in plasma samples of H5N1 vaccinated human subjects. Together, these results suggest that in addition to Fc-FcγR binding, interactions between HA and sialic acids on immune cells are required for optimal Fc-mediated effector functions by anti-HA antibodies.

Osteogenic properties of PBLG-g-HA/PLLA nanocomposites.

PubMed

Liao, Lan; Yang, Shuang; Miron, Richard J; Wei, Junchao; Zhang, Yufeng; Zhang, Meng

2014-01-01

New development of biomaterial scaffolds remains a prominent issue for the regeneration of lost or fractured bone. Of these scaffolds, a number of bioactive polymers have been synthesized and fabricated for diverse biological roles. Although recent evidence has demonstrated that composite scaffolds such as HA/PLLA have improved properties when compared to either HA or PLLA alone, recent investigations have demonstrated that the phase compatibility between HA and PLLA layers is weak preventing optimal enhancement of the mechanical properties and making the composites prone to breakdown. In the present study, poly (γ-benzyl-L-glutamate) modified hydroxyapatite/(poly (L-lactic acid)) (PBLG-g-HA/PLLA) composite scaffolds were fabricated with improved phase compatibility and tested for their osteogenic properties in 18 Wistar female rats by analyzing new bone formation in 3 mm bilateral femur defects in vivo. At time points, 2, 4 and 8 weeks post surgery, bone formation was evaluated by µ-CT and histological analysis by comparing 4 treatment groups; 1) blank defect, 2) PLLA, 3) HA/PLLA and 4) PBLG-g-HA/PLLA scaffolds. The in vivo analysis demonstrated that new bone formation was much more prominent in HA/PLLA and PBLG-g-HA/PLLA groups as depicted by µ-CT, H&E staining and immunohistochemistry for collagen I. TRAP staining was also utilized to determine the influence of osteoclast cell number and staining intensity to the various scaffolds. No significant differences in either staining intensity or osteoclast numbers between all treatment modalities was observed, however blank defects did contain a higher number of osteoclast-like cells. The results from the present study illustrate the potential of PBLG-g-HA/PLLA scaffolds for bone tissue engineering applications by demonstrating favorable osteogenic properties.

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.

HC-HA/PTX3 Purified From Amniotic Membrane as Novel Regenerative Matrix: Insight Into Relationship Between Inflammation and Regeneration.

PubMed

Tseng, Scheffer C G

2016-04-01

Human limbal palisade of Vogt is an ideal model for studying and practicing regenerative medicine due to their accessibility. Nonresolving inflammation is a common manifestation of limbal stem cell deficiency, which is the major cause of corneal blindness, and presents as a threat to the success of transplanted limbal epithelial stem cells. Clinical studies have shown that the efficacy of transplantation of limbal epithelial stem cells can be augmented by transplantation of cryopreserved human amniotic membrane (AM), which exerts anti-inflammatory, antiscarring, and antiangiogenic action to promote wound healing. Review of published data to determine the molecular action mechanism explaining how AM exerts the aforementioned therapeutic actions. From the water-soluble extract of cryopreserved AM, we have biochemically purified one novel matrix component termed heavy chain (HC)-hyaluronan (HA)/pentraxin 3 (PTX3) as the key relevant tissue characteristic responsible for the aforementioned AM's efficacy. Heavy chain-HA is a complex formed by a covalent linkage between HA and HC1 of inter-α-trypsin inhibitor (IαI) by tumor necrosis factor-stimulated gene-6 (TSG-6). This complex may then be tightly associated with PTX3 to form HC-HA/PTX3 complex. Besides exerting an anti-inflammatory, antiscarring, and antiangiogenic effects, HC-HA/PTX3 complex also uniquely maintains limbal niche cells to support the quiescence of limbal epithelial stem cells. We envision that HC-HA/PTX3 purified from AM can be used as a unique substrate to refine ex vivo expansion of limbal epithelial stem cells by maintaining stem cell quiescence, self-renewal and fate decision. Furthermore, it can also be deployed as a platform to launch new therapeutics in regenerative medicine by mitigating nonresolving inflammation and reinforcing the well-being of stem cell niche.

Effect of humic acid (HA) on sulfonamide sorption by biochars.

PubMed

Lian, Fei; Sun, Binbin; Chen, Xi; Zhu, Lingyan; Liu, Zhongqi; Xing, Baoshan

2015-09-01

Effect of quantity and fractionation of loaded humic acid (HA) on biochar sorption for sulfonamides was investigated. The HA was applied in two different modes, i.e. pre-coating and co-introduction with sorbate. In pre-coating mode, the polar fractions of HA tended to interact with low-temperature biochars via H-bonding, while the hydrophobic fractions were likely to be adsorbed by high-temperature biochars through hydrophobic and π-π interactions, leading to different composition and structure of the HA adlayers. The influences of HA fractionation on biochar sorption for sulfonamides varied significantly, depending on the nature of interaction between HA fraction and sorbate. Meanwhile, co-introduction of HA with sulfonamides revealed that the effect of HA on sulfonamide sorption was also dependent on HA concentration. These findings suggest that the amount and fractionation of adsorbed HA are tailored by the surface properties of underlying biochars, which differently affect the sorption for organic contaminants. Copyright © 2015 Elsevier Ltd. All rights reserved.

[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.

Changeable HA to improve MIPv6 protocol

NASA Astrophysics Data System (ADS)

Hu, Qing-gui

2015-12-01

For mobile IPv6, home agent (HA) plays an important role. Each mobile node (MN) has a home IP address, it will be not changeable. Also, the home agent (HA) of MN is not changeable. This rule provides the convenient for the ongoing communication without interruption. But it has some obvious drawbacks. Here, the new variable HA scheme is proposed. Every MN has a dynamic cache table, recording the information such as its home address, care-of address, and history address etc. If the accumulated time in one region exceeds that in the hometown, the foreign agent (FA) could become home agent (HA), the home agent could become history agent. Later, the performance of the new protocol is simulated with OPNET software, whose result shows the performance of the new protocol works better than that of the traditional protocol.

Effect of mitomycin on normal dermal fibroblast and HaCat cell: an in vitro study

PubMed Central

Wang, Yao-wen; Ren, Ji-hao; Xia, Kun; Wang, Shu-hui; Yin, Tuan-fang; Xie, Ding-hua; Li, Li-hua

2012-01-01

Objective: To evaluate the effects of mitomycin on the growth of human dermal fibroblast and immortalized human keratinocyte line (HaCat cell), particularly the effect of mitomycin on intracellular messenger RNA (mRNA) synthesis of collagen and growth factors of fibroblast. Methods: The normal dermal fibroblast and HaCat cell were cultured in vitro. Cell cultures were exposed to 0.4 and 0.04 mg/ml of mitomycin solution, and serum-free culture medium was used as control. The cellular morphology change, growth characteristics, cell proliferation, and apoptosis were observed at different intervals. For the fibroblasts, the mRNA expression changes of transforming growth factor (TGF)-β1, basic fibroblast growth factor (bFGF), procollagen I, and III were detected by reverse transcription polymerase chain reaction (RT-PCR). Results: The cultured normal human skin fibroblast and HaCat cell grew exponentially. A 5-min exposure to mitomycin at either 0.4 or 0.04 mg/ml caused marked dose-dependent cell proliferation inhibition on both fibroblasts and HaCat cells. Cell morphology changed, cell density decreased, and the growth curves were without an exponential phase. The fibroblast proliferated on the 5th day after the 5-min exposure of mitomycin at 0.04 mg/ml. Meanwhile, 5-min application of mitomycin at either 0.04 or 0.4 mg/ml induced fibroblast apoptosis but not necrosis. The apoptosis rate of the fibroblast increased with a higher concentration of mytomycin (p<0.05). A 5-min exposure to mitomycin at 0.4 mg/ml resulted in a marked decrease in the mRNA production of TGF-β1, procollagen I and III, and a marked increase in the mRNA production of bFGF. Conclusions: Mitomycin can inhibit fibroblast proliferation, induce fibroblast apoptosis, and regulate intracellular protein expression on mRNA levels. In additon, mitomycin can inhibit HaCat cell proliferation, so epithelial cell needs more protecting to avoid mitomycin’s side effect when it is applied clinically. PMID

Glucocorticoids and Polyamine Inhibitors Synergize to Kill Human Leukemic CEM Cells1

PubMed Central

Miller, Aaron L; Johnson, Betty H; Medh, Rheem D; Townsend, Courtney M; Thompson, E Brad

2002-01-01

Abstract Glucocorticoids are well-known apoptotic agents in certain classes of lymphoid cell malignancies. Reduction of intracellular polyamine levels by use of inhibitors that block polyamine synthesis slows or inhibits growth of many cells in vitro. Several such inhibitors have shown efficacy in clinical trials, though the toxicity of some compounds has limited their usefulness. We have tested the effects of combinations of the glucocorticoid dexamethasone (Dex) and two polyamine inhibitors, difluoromethylornithine (DFMO) and methyl glyoxal bis guanylhydrazone (MGBG), on the clonal line of human acute lymphoblastic leukemia cells, CEM-C7-14. Dex alone kills these cells, though only after a delay of at least 24 hours. We also evaluated a partially glucocorticoid-resistant c-Myc-expressing CEM-C7-14 clone. We show that Dex downregulates ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis. Pretreatment with the ODC inhibitor DFMO, followed by addition of Dex, enhances steroid-evoked kill slightly. The combination of pretreatment with sublethal concentrations of both DFMO and the inhibitor of S-adenosylmethionine decarboxylase, MGBG, followed by addition of Dex, results in strong synergistic cell kill. Both the rapidity and extent of cell kill are enhanced compared to the effects of Dex alone. These results suggest that use of such combinations in vivo may result in apoptosis of malignant cells with lower overall toxicity. PMID:11922393

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.

Monosaccharides as Scaffolds for the Synthesis of Novel Compounds

NASA Astrophysics Data System (ADS)

Murphy, Paul V.; Velasco-Torrijos, Trinidad

This chapter focuses on monosaccharides and scaffolds their derivatives as scaffolds for the synthesis of primarily bioactive compounds. Such carbohydrate derivatives have been designed to modulate mainly protein-protein and peptide-protein interactions although modulators of carbohydrate-protein and carbohydrate-nucleic acid interactions have also been of interest. The multiple hydroxyl groups that are present on saccharides have made pyranose, furanose and iminosugars ideal templates or scaffolds to which recognition or pharmacophoric groups can be grafted to generate novel compounds for medicinal chemistry. The synthesis of compounds for evaluations require strategies for regioselective reactions of saccharide hydroxyl groups and use of orthogonally stable protecting groups. Syntheses have been carried out on the solid phase and in solution. Also the use of uronic acids, amino sugars and sugar amino acids has facilitated the synthesis of peptidomimetics and prospecting libraries as they enable, through presence of amino or carboxylic acid groups, chemoselective approaches to be employed in solution and on solid phase. Sugar amino acids are readily incorporated, as peptide isosteres, to generate sugar-peptide hybrids or for the synthesis of novel carbopeptoids . The synthesis of new cyclic compounds, derived in part from saccharides, and their application as scaffolds is an emerging area and recent examples include spirocyclic compounds, benzodiazepine-saccharide hybrids and macrolide-saccharide hybrids. Potent bioactive saccharide derivatives have been identified that include enzyme inhibitors , somatostatin receptor ligands, integrin ligands, anti-viral compounds, shiga toxin inhibitors and cell growth inhibitors. Some saccharide derivatives have demonstrated improved cellular permeability when compared with peptides and are in clinical trials.

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.

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

Registration of two confection sunflower germplasm Lines, HA-R10 and HA-R11, Resistant to sunflower rust

USDA-ARS?s Scientific Manuscript database

Two confection sunflower (Helianthus annuus L.) germplasm lines, HA-R10 (Reg. No.xxx, PI670043) and HA-R11 (Reg. No.xxx, PI670044) were developed by the USDA-ARS Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station and released December, 20...

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.

Putative suppressing effect of IgG Fc-conjugated haemagglutinin (HA) stalk of influenza virus H7N9 on the neutralizing immunogenicity of Fc-conjugated HA head: implication for rational design of HA-based influenza vaccines.

PubMed

He, B; Xia, S; Yu, F; Fu, Y; Li, W; Wang, Q; Lu, L; Jiang, S

2016-02-01

The emergence of influenza A H7N9 in infection has posed a great threat to public health globally. Poor immunogenicity of H7N9 haemagglutinin (HA) is a major obstacle to the development of an effective H7N9 vaccine. Here, we found that the vaccine containing the H7HA head conjugated with IgG Fc (Hd-Fc) induced strong neutralizing antibody responses and protection against H7N9 infection, whilst the Fc-conjugated H7HA stalk (St-Fc)-based vaccine could not induce neutralizing antibodies, although the St-Fc-immunized mice were partially protected. The vaccines containing the full-length extracellular domain of HA conjugated with Fc and the mixture of Hd-Fc plus St-Fc induced significantly lower neutralizing antibody and haemagglutination inhibition titres than the Hd-Fc-based vaccine. These results suggest that the St-Fc may have inhibitory effects on the neutralizing immunogenicity of Hd-Fc. Therefore, the neutralizing domain(s), such as the receptor-binding domain, in the HA head should be kept and the non-neutralizing domain(s) in the HA stalk with the ability to potentially suppress the neutralizing immunogenicity of HA head should be removed from Fc-conjugated HA-based influenza vaccines to increase the neutralizing antibody response.

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.

Hierarchically nanostructured hydroxyapatite: hydrothermal synthesis, morphology control, growth mechanism, and biological activity

PubMed Central

Ma, Ming-Guo

2012-01-01

Hierarchically nanosized hydroxyapatite (HA) with flower-like structure assembled from nanosheets consisting of nanorod building blocks was successfully synthesized by using CaCl2, NaH2PO4, and potassium sodium tartrate via a hydrothermal method at 200°C for 24 hours. The effects of heating time and heating temperature on the products were investigated. As a chelating ligand and template molecule, the potassium sodium tartrate plays a key role in the formation of hierarchically nanostructured HA. On the basis of experimental results, a possible mechanism based on soft-template and self-assembly was proposed for the formation and growth of the hierarchically nanostructured HA. Cytotoxicity experiments indicated that the hierarchically nanostructured HA had good biocompatibility. It was shown by in-vitro experiments that mesenchymal stem cells could attach to the hierarchically nanostructured HA after being cultured for 48 hours. Objective The purpose of this study was to develop facile and effective methods for the synthesis of novel hydroxyapatite (HA) with hierarchical nanostructures assembled from independent and discrete nanobuilding blocks. Methods A simple hydrothermal approach was applied to synthesize HA by using CaCl2, NaH2PO4, and potassium sodium tartrate at 200°C for 24 hours. The cell cytotoxicity of the hierarchically nanostructured HA was tested by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Results HA displayed the flower-like structure assembled from nanosheets consisting of nanorod building blocks. The potassium sodium tartrate was used as a chelating ligand, inducing the formation and self-assembly of HA nanorods. The heating time and heating temperature influenced the aggregation and morphology of HA. The cell viability did not decrease with the increasing concentration of hierarchically nanostructured HA added. Conclusion A novel, simple and reliable hydrothermal route had been developed for the synthesis of

Synthesis, biological evaluation, and docking studies of gigantol analogs as calmodulin inhibitors.

PubMed

Reyes-Ramírez, Adelfo; Leyte-Lugo, Martha; Figueroa, Mario; Serrano-Alba, Trinidad; González-Andrade, Martín; Mata, Rachel

2011-07-01

Several analogs of gigantol (1) were synthesized to evaluate their effect on the complexes Ca(2+)-calmodulin (CaM) and Ca(2+)-CaM-CaM sensitive phosphodiesterase 1 (PDE1). The compounds belong to four structural groups including, 1,2-diphenylethanes (2-11), diphenylmethanes (13-15), 1,3-diphenylpropenones (16-18), and 1,3-diphenylpropanes (20-22). In vitro enzymatic studies showed that all compounds except 11 inhibited the complex Ca(2+)-CaM-PDE1 with IC(50) values ranging from 9 to 146 μM. On the other hand, all analogs but 11, 12 and 15 quenched the extrinsic fluorescence of the CaM biosensor hCaM-M124C-mBBr to different extent, then revealing different affinities to CaM; their affinity constants (K(m)) values were in the range of 3-80 μM. Molecular modeling studies indicated that all these compounds bound to CaM at the same site that the classical inhibitors trifluoperazine (TFP) and chlorpromazine (CPZ). Some of these analogs could be worthy candidates for developing new anti-tumor, local anesthetics, antidepressants, antipsychotic, or smooth muscle relaxant drugs, with anti-CaM properties due to their good affinity to CaM and the straightforwardness of their synthesis. In addition they could be valuable tools for the study of Ca(2+)-CaM functions. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Biomimetic composite microspheres of collagen/chitosan/nano-hydroxyapatite: In-situ synthesis and characterization.

PubMed

Teng, Shu-Hua; Liang, Mian-Hui; Wang, Peng; Luo, Yong

2016-01-01

The collagen/chitosan/hydroxyapatite (COL/CS/HA) composite microspheres with a good spherical form and a high dispersity were successfully obtained using an in-situ synthesis method. The FT-IR and XRD results revealed that the inorganic phase in the microspheres was crystalline HA containing carbonate ions. The morphology of the composite microspheres was dependent on the HA content, and a more desirable morphology was achieved when 20 wt.% HA was contained. The composite microspheres exhibited a narrow particle distribution, most of which ranged from 5 to 10 μm. In addition, the needle-like HA nano-particles were uniformly distributed in the composite microspheres, and their crystallinity and crystal size decreased with the HA content. Copyright © 2015 Elsevier B.V. All rights reserved.

Generation of recombinant pandemic H1N1 influenza virus with the HA cleavable by bromelain and identification of the residues influencing HA bromelain cleavage.

PubMed

Wang, Weijia; Suguitan, Amorsolo L; Zengel, James; Chen, Zhongying; Jin, Hong

2012-01-20

The proteolytic enzyme bromelain has been traditionally used to cleave the hemagglutinin (HA) protein at the C-terminus of the HA2 region to release the HA proteins from influenza virions. The bromelain cleaved HA (BHA) has been routinely used as an antigen to generate antiserum that is essential for influenza vaccine product release. The HA of the 2009 pandemic H1N1 influenza A/California/7/2009 (CA09) virus could not be cleaved efficiently by bromelain. To ensure timely delivery of BHA for antiserum production, we generated a chimeric virus that contained the HA1 region from CA09 and the HA2 region from the seasonal H1N1 A/South Dakota/6/2007 (SD07) virus that is cleavable by bromelain. The BHA from this chimeric virus was antigenically identical to CA09 and induced high levels of HA-specific antibodies and protected ferrets from wild-type H1N1 CA09 virus challenge. To determine the molecular basis of inefficient cleavage of CA09 HA by bromelain, the amino acids that differed between the HA2 of CA09 and SD07 were introduced into recombinant CA09 virus to assess their effect on bromelain cleavage. The D373N or E374G substitution in the HA2 stalk region of CA09 HA enabled efficient cleavage of CA09 HA by bromelain. Sequence analysis of the pandemic H1N1-like viruses isolated from 2010 revealed emergence of the E374K change. We found that K374 enabled the HA to be cleaved by bromelain and confirmed that the 374 residue is critical for HA bromelain cleavage. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Dietary flavonoid fisetin increases abundance of high-molecular-mass hyaluronan conferring resistance to prostate oncogenesis.

PubMed

Lall, Rahul K; Syed, Deeba N; Khan, Mohammad Imran; Adhami, Vaqar M; Gong, Yuansheng; Lucey, John A; Mukhtar, Hasan

2016-09-01

We and others have shown previously that fisetin, a plant flavonoid, has therapeutic potential against many cancer types. Here, we examined the probable mechanism of its action in prostate cancer (PCa) using a global metabolomics approach. HPLC-ESI-MS analysis of tumor xenografts from fisetin-treated animals identified several metabolic targets with hyaluronan (HA) as the most affected. Efficacy of fisetin on HA was then evaluated in vitro and also in vivo in the transgenic TRAMP mouse model of PCa. Size exclusion chromatography-multiangle laser light scattering (SEC-MALS) was performed to analyze the molar mass (Mw) distribution of HA. Fisetin treatment downregulated intracellular and secreted HA levels both in vitro and in vivo Fisetin inhibited HA synthesis and degradation enzymes, which led to cessation of HA synthesis and also repressed the degradation of the available high-molecular-mass (HMM)-HA. SEC-MALS analysis of intact HA fragment size revealed that cells and animals have more abundance of HMM-HA and less of low-molecular-mass (LMM)-HA upon fisetin treatment. Elevated HA levels have been shown to be associated with disease progression in certain cancer types. Biological responses triggered by HA mainly depend on the HA polymer length where HMM-HA represses mitogenic signaling and has anti-inflammatory properties whereas LMM-HA promotes proliferation and inflammation. Similarly, Mw analysis of secreted HA fragment size revealed less HMM-HA is secreted that allowed more HMM-HA to be retained within the cells and tissues. Our findings establish that fisetin is an effective, non-toxic, potent HA synthesis inhibitor, which increases abundance of antiangiogenic HMM-HA and could be used for the management of PCa. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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.

INVITED REVIEW: Inhibitors of myostatin as methods of enhancing muscle growth and development.

PubMed

Chen, P R; Lee, K

2016-08-01

With the increasing demand for affordable, high-quality meat, livestock and poultry producers must continually find ways to maximize muscle growth in their animals without compromising palatability of the meat products. Muscle mass relies on myoblast proliferation during prenatal or prehatch stages and fiber hypertrophy through protein synthesis and nuclei donation by satellite cells after birth or hatch. Therefore, understanding the cellular and molecular mechanisms of myogenesis and muscle development is of great interest. Myostatin is a well-known negative regulator of muscle growth and development that inhibits proliferation and differentiation in myogenic cells as well as protein synthesis in existing muscle fibers. In this review, various inhibitors of myostatin activity or signaling are examined that may be used in animal agriculture for enhancing muscle growth. Myostatin inhibitors are relevant as potential therapies for muscle-wasting diseases and muscle weakness in humans and animals. Currently, there are no commercial myostatin inhibitors for agriculture or biomedical purposes because the safest and most effective option has yet to be identified. Further investigation of myostatin inhibitors and administration strategies may revolutionize animal production and the medical field.

Polypeptide from Chlamys farreri inhibits UVB-induced apoptosis of HaCaT cells via iNOS/NO and HSP90

NASA Astrophysics Data System (ADS)

Zhang, Zhengyang; Liu, Xiaojin; Liu, Tuo; Yan, Lin; Wang, Yuejun; Wang, Chunbo

2009-09-01

Polypeptide from Chlamys farreri (PCF) is a novel marine bioactive product that was isolated from the gonochoric Chinese scallop Chlamys farreri, and was found to be an effective antioxidant in our recent studies. In this study, we investigated the effect of PCF on ultraviolet B (UVB)-induced apoptosis of HaCaT cells and the intracellular signaling pathways involved. Pretreatment with the inducible nitric oxide synthase (iNOS) inhibitor S-methylisothiourea sulfate inhibited UVB-induced apoptosis, indicating that iNOS and NO play important roles in apoptosis. On the other hand, the inhibition of UVB-induced apoptosis in the immortalized keratinocyte (HaCaT) cells by PCF was estimated using a DNA ladder. PCF treatment inhibited UVB-induced iNOS activation, as determined by RT-PCR, NO production, as determined by ESR, and up-regulated heat shock protein (HSP) 90 activation, as determined by Western blotting. Our results indicate that iNOS and NO are involved in UVB-induced apoptosis of HaCaT cells and the protective effect of PCF against UVB irradiation is exerted by suppressing the expression of iNOS, followed by inhibition of NO release and enhanced activation of HSP90.

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

Structure-based optimization of Cephalothin-analogue boronic acids as β-lactamase inhibitors

PubMed Central

Morandi, Stefania; Morandi, Federica; Caselli, Emilia; Shoichet, Brian K.; Prati, Fabio

2008-01-01

Boronic acids have proved to be promising selective inhibitors of β-lactamases, acting as transition state analogues. Starting from a previously described nanomolar inhibitor of AmpC β-lactamase, three new inhibitors were designed to gain interactions with highly conserved residues, such as Asn343, and to bind more tightly to the enzyme. Among these, one was obtained by stereoselective synthesis and succeeded in placing its anionic group into the carboxylate binding site of the enzyme, as revealed by X-ray crystallography of the complex inhibitor/AmpC. Nevertheless, it failed at improving affinity, when compared to the lead from which it was derived. The origins of this structural and energetic discrepancy are discussed. PMID:17997318

Synthetic (p)ppGpp Analogue Is an Inhibitor of Stringent Response in Mycobacteria.

PubMed

Syal, Kirtimaan; Flentie, Kelly; Bhardwaj, Neerupma; Maiti, Krishnagopal; Jayaraman, Narayanaswamy; Stallings, Christina L; Chatterji, Dipankar

2017-06-01

Bacteria elicit an adaptive response against hostile conditions such as starvation and other kinds of stresses. Their ability to survive such conditions depends, in part, on stringent response pathways. (p)ppGpp, considered to be the master regulator of the stringent response, is a novel target for inhibiting the survival of bacteria. In mycobacteria, the (p)ppGpp synthetase activity of bifunctional Rel is critical for stress response and persistence inside a host. Our aim was to design an inhibitor of (p)ppGpp synthesis, monitor its efficiency using enzyme kinetics, and assess its phenotypic effects in mycobacteria. As such, new sets of inhibitors targeting (p)ppGpp synthesis were synthesized and characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. We observed significant inhibition of (p)ppGpp synthesis by Rel Msm in the presence of designed inhibitors in a dose-dependent manner, which we further confirmed by monitoring the enzyme kinetics. The Rel enzyme inhibitor binding kinetics were investigated by isothermal titration calorimetry. Subsequently, the effects of the compounds on long-term persistence, biofilm formation, and biofilm disruption were assayed in Mycobacterium smegmatis , where inhibition in each case was observed. In vivo , (p)ppGpp levels were found to be downregulated in M. smegmatis treated with the synthetic inhibitors. The compounds reported here also inhibited biofilm formation by the pathogen Mycobacterium tuberculosis The compounds were tested for toxicity by using an MTT assay with H460 cells and a hemolysis assay with human red blood cells, for which they were found to be nontoxic. The permeability of compounds across the cell membrane of human lung epithelial cells was also confirmed by mass spectrometry. Copyright © 2017 American Society for Microbiology.

Aptamer antagonists of myelin-derived inhibitors promote axon growth.

PubMed

Wang, Yuxuan; Khaing, Zin Z; Li, Na; Hall, Brad; Schmidt, Christine E; Ellington, Andrew D

2010-03-16

Myelin of the adult central nervous system (CNS) is one of the major sources of inhibitors of axon regeneration following injury. The three known myelin-derived inhibitors (Nogo, MAG, and OMgp) bind with high affinity to the Nogo-66 receptor (NgR) on axons and limit neurite outgrowth. Here we show that RNA aptamers can be generated that bind with high affinity to NgR, compete with myelin-derived inhibitors for binding to NgR, and promote axon elongation of neurons in vitro even in the presence of these inhibitors. Aptamers may have key advantages over protein antagonists, including low immunogenicity and the possibility of ready modification during chemical synthesis for stability, signaling, or immobilization. This first demonstration that aptamers can directly influence neuronal function suggests that aptamers may prove useful for not only healing spinal cord and other neuronal damage, but may be more generally useful as neuromodulators.

Aptamer Antagonists of Myelin-Derived Inhibitors Promote Axon Growth

PubMed Central

Wang, Yuxuan; Khaing, Zin Z.; Li, Na; Hall, Brad; Schmidt, Christine E.; Ellington, Andrew D.

2010-01-01

Myelin of the adult central nervous system (CNS) is one of the major sources of inhibitors of axon regeneration following injury. The three known myelin-derived inhibitors (Nogo, MAG, and OMgp) bind with high affinity to the Nogo-66 receptor (NgR) on axons and limit neurite outgrowth. Here we show that RNA aptamers can be generated that bind with high affinity to NgR, compete with myelin-derived inhibitors for binding to NgR, and promote axon elongation of neurons in vitro even in the presence of these inhibitors. Aptamers may have key advantages over protein antagonists, including low immunogenicity and the possibility of ready modification during chemical synthesis for stability, signaling, or immobilization. This first demonstration that aptamers can directly influence neuronal function suggests that aptamers may prove useful for not only healing spinal cord and other neuronal damage, but may be more generally useful as neuromodulators. PMID:20300533

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

PubMed

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

2014-06-14

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

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

Preparation and characterization of bio-composite PEEK/nHA

NASA Astrophysics Data System (ADS)

Jin, Y. S.; Bian, C. C.; Zhang, Z. Q.; Zhao, Y.; Yang, L.

2017-01-01

PEEK/nHA composite material, with excellent mechanical property as polyetheretherketone (PEEK) and biological activity as hydroxyapatite (HA), has attracted wide attention of medical experts and materials science experts. The addition of hydroxyapatite was the decisive factor for biological activity in PEEK/nHA composite. In this paper, acicular nanohydroxyapatite was prepared by chemical precipitation method with Ca(NO3)2, (NH4)2HPO4 as raw material; PEEK/nHA composite was prepared by solution blending and vacuum sintering method. The composite was characterized with FT-IR, XRD, DSC, TG and mechanical property test. Results showed that the composite has good thermal stability and compressive property when the mass ratio of PEEK to nHA is 10:3; and high nHA content can improve the biological activity of the composite, which can meet the basic requirements for bone tissue engineering scaffold.

Synthesis and evaluation of phosphorus containing, specific CDK9/CycT1 inhibitors.

PubMed

Németh, Gábor; Greff, Zoltán; Sipos, Anna; Varga, Zoltán; Székely, Rita; Sebestyén, Mónika; Jászay, Zsuzsa; Béni, Szabolcs; Nemes, Zoltán; Pirat, Jean-Luc; Volle, Jean-Noël; Virieux, David; Gyuris, Ágnes; Kelemenics, Katalin; Ay, Eva; Minarovits, Janos; Szathmary, Susan; Kéri, György; Orfi, László

2014-05-22

Although there is a significant effort in the design of a selective CDK9/CycT1 inhibitor, no compound has been proven to be a specific inhibitor of this kinase so far. The aim of this research was to develop novel and selective phosphorus containing CDK9/CycT1 inhibitors. Molecules bearing phosphonamidate, phosphonate, and phosphinate moieties were synthesized. Prepared compounds were evaluated in an enzymatic CDK9/CycT1 assay. The most potent molecules were tested in cell-based toxicity and HIV proliferation assays. Selectivity of shortlisted compounds against CDKs and other kinases was tested. The best compound was shown to be a highly specific, ATP-competitive inhibitor of CDK9/CycT1 with antiviral activity.

Microwave-Assisted Synthesis – Catalytic Applications in Aqueous Media

EPA Science Inventory

The development of sustainable methods directed towards the synthesis of molecules is due to the heightened awareness and recognition of alternative eco-friendly and economical protocols that have minimum impact on environment. Among others, microwave (MW)-assisted methodology ha...

Hyaluronan (HA) interacting proteins RHAMM and hyaluronidase impact prostate cancer cell behavior and invadopodia formation in 3D HA-based hydrogels.

PubMed

Gurski, Lisa A; Xu, Xian; Labrada, Lyana N; Nguyen, Ngoc T; Xiao, Longxi; van Golen, Kenneth L; Jia, Xinqiao; Farach-Carson, Mary C

2012-01-01

To study the individual functions of hyaluronan interacting proteins in prostate cancer (PCa) motility through connective tissues, we developed a novel three-dimensional (3D) hyaluronic acid (HA) hydrogel assay that provides a flexible, quantifiable, and physiologically relevant alternative to current methods. Invasion in this system reflects the prevalence of HA in connective tissues and its role in the promotion of cancer cell motility and tissue invasion, making the system ideal to study invasion through bone marrow or other HA-rich connective tissues. The bio-compatible cross-linking process we used allows for direct encapsulation of cancer cells within the gel where they adopt a distinct, cluster-like morphology. Metastatic PCa cells in these hydrogels develop fingerlike structures, "invadopodia", consistent with their invasive properties. The number of invadopodia, as well as cluster size, shape, and convergence, can provide a quantifiable measure of invasive potential. Among candidate hyaluronan interacting proteins that could be responsible for the behavior we observed, we found that culture in the HA hydrogel triggers invasive PCa cells to differentially express and localize receptor for hyaluronan mediated motility (RHAMM)/CD168 which, in the absence of CD44, appears to contribute to PCa motility and invasion by interacting with the HA hydrogel components. PCa cell invasion through the HA hydrogel also was found to depend on the activity of hyaluronidases. Studies shown here reveal that while hyaluronidase activity is necessary for invadopodia and inter-connecting cluster formation, activity alone is not sufficient for acquisition of invasiveness to occur. We therefore suggest that development of invasive behavior in 3D HA-based systems requires development of additional cellular features, such as activation of motility associated pathways that regulate formation of invadopodia. Thus, we report development of a 3D system amenable to dissection of

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

PubMed

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

2014-12-26

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

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.

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.

Inhibitors Selective for Mycobacterial Versus Human Proteasomes

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

Lin, G.; Li, D; Sorio de Carvalho, L

Many anti-infectives inhibit the synthesis of bacterial proteins, but none selectively inhibits their degradation. Most anti-infectives kill replicating pathogens, but few preferentially kill pathogens that have been forced into a non-replicating state by conditions in the host. To explore these alternative approaches we sought selective inhibitors of the proteasome of Mycobacterium tuberculosis. Given that the proteasome structure is extensively conserved, it is not surprising that inhibitors of all chemical classes tested have blocked both eukaryotic and prokaryotic proteasomes, and no inhibitor has proved substantially more potent on proteasomes of pathogens than of their hosts. Here we show that certain oxathiazol-2-onemore » compounds kill non-replicating M.?tuberculosis and act as selective suicide-substrate inhibitors of the M.?tuberculosis proteasome by cyclocarbonylating its active site threonine. Major conformational changes protect the inhibitor-enzyme intermediate from hydrolysis, allowing formation of an oxazolidin-2-one and preventing regeneration of active protease. Residues outside the active site whose hydrogen bonds stabilize the critical loop before and after it moves are extensively non-conserved. This may account for the ability of oxathiazol-2-one compounds to inhibit the mycobacterial proteasome potently and irreversibly while largely sparing the human homologue.« less

Synthesis of pyrimidin-2-one nucleosides as acid-stable inhibitors of cytidine deaminase.

PubMed

Kim, C H; Marquez, V E; Mao, D T; Haines, D R; McCormack, J J

1986-08-01

One of the problems encountered in the use of tetrahydrouridine (THU, 2) and saturated 2-oxo-1,3-diazepine nucleosides as orally administered cytidine deaminase (CDA) inhibitors is their acid instability. Under acid conditions these compounds are rapidly converted into inactive ribopyranoside forms. A solution this problem was sought by functionalizing the acid-stable but less potent CDA inhibitor 1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (1) with the hope of increasing its potency to the level achieved with THU. The selection of the hydroxymethyl substituent at C-4, which led to the synthesis of 4-(hydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (10), 3,4-dihydro-4-(hydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (7), and 3,4,5,6-tetrahydro-4-(dihydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-p yrimidinone (28) was based on the transition-state (TS) concept. The key intermediate precursor, 4-[(benzoyloxy)methyl]-1-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-2(H) -pyrimidinone (24), was obtained via the classical Hilbert-Johnson reaction between 2-methoxy-4-[(benzoyloxy)methyl]pyrimidine (20) and 2,3,5-tri-O-benzoyl-1-D-ribofuranosyl bromide (21). Deprotection of 24 afforded compound 10, while its sodium borohydride reduction products afforded compounds 7 and 28 after removal of the blocking groups. Syntheses of 3,4-dihydro-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (9) and 3,6-dihydro-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (8), which lack the hydroxymethyl substituent, was accomplished in a similar fashion. The new compounds bearing the hydroxymethyl substituent were more acid stable than THU, and their CDA inhibitory potency, expressed in terms of Ki values, spanned from 10(-4) to 10(-7) M in a manner consistent with the TS theory. Compound 7, in particular, was superior to its parent 1 and equipotent to THU (Ki = 4 X 10(-7) M) when examined against mouse kidney CDA. The superior acid stability of this compound coupled to its potent inhibitory

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.

Pollination in Nicotiana alata stimulates synthesis and transfer to the stigmatic surface of NaStEP, a vacuolar Kunitz proteinase inhibitor homologue

PubMed Central

Busot, Grethel Yanet; McClure, Bruce; Ibarra-Sánchez, Claudia Patricia; Jiménez-Durán, Karina; Vázquez-Santana, Sonia; Cruz-García, Felipe

2008-01-01

After landing on a wet stigma, pollen grains hydrate and germination generally occurs. However, there is no certainty of the pollen tube growth through the style to reach the ovary. The pistil is a gatekeeper that evolved in many species to recognize and reject the self-pollen, avoiding endogamy and encouraging cross-pollination. However, recognition is a complex process, and specific factors are needed. Here the isolation and characterization of a stigma-specific protein from N. alata, NaStEP (N. alata Stigma Expressed Protein), that is homologous to Kunitz-type proteinase inhibitors, are reported. Activity gel assays showed that NaStEP is not a functional serine proteinase inhibitor. Immunohistochemical and protein blot analyses revealed that NaStEP is detectable in stigmas of self-incompatible (SI) species N. alata, N. forgetiana, and N. bonariensis, but not in self-compatible (SC) species N. tabacum, N. plumbaginifolia, N. benthamiana, N. longiflora, and N. glauca. NaStEP contains the vacuolar targeting sequence NPIVL, and immunocytochemistry experiments showed vacuolar localization in unpollinated stigmas. After self-pollination or pollination with pollen from the SC species N. tabacum or N. plumbaginifolia, NaStEP was also found in the stigmatic exudate. The synthesis and presence in the stigmatic exudate of this protein was strongly induced in N. alata following incompatible pollination with N. tabacum pollen. The transfer of NaStEP to the stigmatic exudate was accompanied by perforation of the stigmatic cell wall, which appeared to release the vacuolar contents to the apoplastic space. The increase in NaStEP synthesis after pollination and its presence in the stigmatic exudates suggest that this protein may play a role in the early pollen–stigma interactions that regulate pollen tube growth in Nicotiana. PMID:18689443

Pollination in Nicotiana alata stimulates synthesis and transfer to the stigmatic surface of NaStEP, a vacuolar Kunitz proteinase inhibitor homologue.

PubMed

Busot, Grethel Yanet; McClure, Bruce; Ibarra-Sánchez, Claudia Patricia; Jiménez-Durán, Karina; Vázquez-Santana, Sonia; Cruz-García, Felipe

2008-01-01

After landing on a wet stigma, pollen grains hydrate and germination generally occurs. However, there is no certainty of the pollen tube growth through the style to reach the ovary. The pistil is a gatekeeper that evolved in many species to recognize and reject the self-pollen, avoiding endogamy and encouraging cross-pollination. However, recognition is a complex process, and specific factors are needed. Here the isolation and characterization of a stigma-specific protein from N. alata, NaStEP (N. alata Stigma Expressed Protein), that is homologous to Kunitz-type proteinase inhibitors, are reported. Activity gel assays showed that NaStEP is not a functional serine proteinase inhibitor. Immunohistochemical and protein blot analyses revealed that NaStEP is detectable in stigmas of self-incompatible (SI) species N. alata, N. forgetiana, and N. bonariensis, but not in self-compatible (SC) species N. tabacum, N. plumbaginifolia, N. benthamiana, N. longiflora, and N. glauca. NaStEP contains the vacuolar targeting sequence NPIVL, and immunocytochemistry experiments showed vacuolar localization in unpollinated stigmas. After self-pollination or pollination with pollen from the SC species N. tabacum or N. plumbaginifolia, NaStEP was also found in the stigmatic exudate. The synthesis and presence in the stigmatic exudate of this protein was strongly induced in N. alata following incompatible pollination with N. tabacum pollen. The transfer of NaStEP to the stigmatic exudate was accompanied by perforation of the stigmatic cell wall, which appeared to release the vacuolar contents to the apoplastic space. The increase in NaStEP synthesis after pollination and its presence in the stigmatic exudates suggest that this protein may play a role in the early pollen-stigma interactions that regulate pollen tube growth in Nicotiana.

Structure–Activity Relationship Studies and in Vivo Activity of Guanidine-Based Sphingosine Kinase Inhibitors: Discovery of SphK1- and SphK2-Selective Inhibitors

PubMed Central

Kharel, Yugesh; Raje, Mithun R.; Gao, Ming; Tomsig, Jose L.; Lynch, Kevin R.; Santos, Webster L.

2015-01-01

Sphingosine 1-phosphate (S1P) is a pleiotropic signaling molecule that acts as a ligand for five G-protein coupled receptors (S1P1–5) whose downstream effects are implicated in a variety of important pathologies including sickle cell disease, cancer, inflammation, and fibrosis. The synthesis of S1P is catalyzed by sphingosine kinase (SphK) isoforms 1 and 2, and hence, inhibitors of this phosphorylation step are pivotal in understanding the physiological functions of SphKs. To date, SphK1 and 2 inhibitors with the potency, selectivity, and in vivo stability necessary to determine the potential of these kinases as therapeutic targets are lacking. Herein, we report the design, synthesis, and structure–activity relationship studies of guanidine-based SphK inhibitors bearing an oxadiazole ring in the scaffold. Our studies demonstrate that SLP120701, a SphK2-selective inhibitor (Ki = 1 μM), decreases S1P levels in histiocytic lymphoma (U937) cells. Surprisingly, homologation with a single methylene unit between the oxadiazole and heterocyclic ring afforded a SphK1-selective inhibitor in SLP7111228 (Ki = 48 nM), which also decreased S1P levels in cultured U937 cells. In vivo application of both compounds, however, resulted in contrasting effect in circulating levels of S1P. Administration of SLP7111228 depressed blood S1P levels while SLP120701 increased levels of S1P. Taken together, these compounds provide an in vivo chemical toolkit to interrogate the effect of increasing or decreasing S1P levels and whether such a maneuver can have implications in disease states. PMID:25643074

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.

Discovery of Ecopladib, an indole inhibitor of cytosolic phospholipase A2alpha.

PubMed

Lee, Katherine L; Foley, Megan A; Chen, Lihren; Behnke, Mark L; Lovering, Frank E; Kirincich, Steven J; Wang, Weiheng; Shim, Jaechul; Tam, Steve; Shen, Marina W H; Khor, Soopeang; Xu, Xin; Goodwin, Debra G; Ramarao, Manjunath K; Nickerson-Nutter, Cheryl; Donahue, Frances; Ku, M Sherry; Clark, James D; McKew, John C

2007-03-22

The synthesis and structure-activity relationship of a series of indole inhibitors of cytosolic phospholipase A2alpha (cPLA2alpha, type IVA phospholipase) are described. Inhibitors of cPLA2alpha are predicted to be efficacious in treating asthma as well as the signs and symptoms of osteoarthritis, rheumatoid arthritis, and pain. The introduction of a benzyl sulfonamide substituent at C2 was found to impart improved potency of these inhibitors, and the SAR of these sulfonamide analogues is disclosed. Compound 123 (Ecopladib) is a sub-micromolar inhibitor of cPLA2alpha in the GLU micelle and rat whole blood assays. Compound 123 displayed oral efficacy in the rat carrageenan air pouch and rat carrageenan-induced paw edema models.

Influence of insertion site of the avian influenza virus haemagglutinin (HA) gene within the Newcastle disease virus genome on HA expression.

PubMed

Ramp, Kristina; Skiba, Martin; Karger, Axel; Mettenleiter, Thomas C; Römer-Oberdörfer, Angela

2011-02-01

Members of the order Mononegavirales express their genes in a transcription gradient from 3' to 5'. To assess how this impacts on expression of a foreign transgene, the haemagglutinin (HA) of highly pathogenic avian influenza virus (HPAIV) A/chicken/Vietnam/P41/05 (subtype H5N1) was inserted between the phosphoprotein (P) and matrix protein (M), M and fusion protein (F), or F and haemagglutinin-neuraminidase protein (HN) genes of attenuated Newcastle disease virus (NDV) Clone 30. In addition, the gene encoding the neuraminidase of HPAIV A/duck/Vietnam/TG24-01/05 (subtype H5N1) was inserted into the NDV genome either alone or in combination with the HA gene. All recombinants replicated well in embryonated chicken eggs. The expression levels of HA-specific mRNA and protein were quantified by Northern blot analysis and mass spectrometry, with good correlation. HA expression levels differed only moderately and were highest in the recombinant carrying the HA insertion between the F and HN genes of NDV.

Serum inter-alpha-trypsin inhibitor and matrix hyaluronan promote angiogenesis in fibrotic lung injury.

PubMed

Garantziotis, Stavros; Zudaire, Enrique; Trempus, Carol S; Hollingsworth, John W; Jiang, Dianhua; Lancaster, Lisa H; Richardson, Elizabeth; Zhuo, Lisheng; Cuttitta, Frank; Brown, Kevin K; Noble, Paul W; Kimata, Koji; Schwartz, David A

2008-11-01

The etiology and pathogenesis of angiogenesis in idiopathic pulmonary fibrosis (IPF) is poorly understood. Inter-alpha-trypsin inhibitor (IaI) is a serum protein that can bind to hyaluronan (HA) and may contribute to the angiogenic response to tissue injury. To determine whether IaI promotes HA-mediated angiogenesis in tissue injury. An examination was undertaken of angiogenesis in IaI-sufficient and -deficient mice in the bleomycin model of pulmonary fibrosis and in angiogenesis assays in vivo and in vitro. IaI and HA in patients with IPF were examined. IaI significantly enhances the angiogenic response to short-fragment HA in vivo and in vitro. lal deficiency Ieads to decreased angiogenesis in the matrigel model, and decreases lung angiogenesis after bleomycin exposure in mice. IaI is found in fibroblastic foci in IPF, where it colocalizes with HA. The colocalization is particularly strong in vascular areas around fibroblastic foci. Serum levels of IaI and HA are significantly elevated in patients with IPF compared with control subjects. High serum IaI and HA levels are associated with decreased lung diffusing capacity, but not FVC. Our findings indicate that serum IaI interacts with HA, and promotes angiogenesis in lung injury. IaI appears to contribute to the vascular response to lung injury and may lead to aberrant angiogenesis. Clinical trial registered with www.clinicaltrials.gov (NCT00016627).

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.

Contribution of Neuraminidase of Influenza Viruses to the Sensitivity to Sera Inhibitors and Reassortment Efficiency

PubMed Central

Kiseleva, Irina; Larionova, Natalie; Fedorova, Ekaterina; Bazhenova, Ekaterina; Dubrovina, Irina; Isakova-Sivak, Irina; Rudenko, Larisa

2014-01-01

Live attenuated influenza vaccine (LAIV) represent reassortant viruses with hemagglutinin (HA) and neuraminidase (NA) gene segments inherited from circulating wild-type (WT) parental influenza viruses recommended for inclusion into seasonal vaccine formulation, and the 6 internal protein-encoding gene segments from cold-adapted attenuated master donor viruses (genome composition 6:2). In this study, we describe the obstacles in developing LAIV strains while taking into account the phenotypic peculiarities of WT viruses used for reassortment. Genomic composition analysis of 849 seasonal LAIV reassortants revealed that over 80% of reassortants based on inhibitor-resistant WT viruses inherited WT NA, compared to 26% of LAIV reassortants based on inhibitor-sensitive WT viruses. In addition, the highest percentage of LAIV genotype reassortants was achieved when WT parental viruses were resistant to non-specific serum inhibitors. We demonstrate that NA may play a role in influenza virus sensitivity to non-specific serum inhibitors. Replacing NA of inhibitor-sensitive WT virus with the NA of inhibitor-resistant master donor virus significantly decreased the sensitivity of the resulting reassortant virus to serum heat-stable inhibitors. PMID:25132869

Osteoinductive-nanoscaled silk/HA composite scaffolds for bone tissue engineering application.

PubMed

Huang, Xiaowei; Bai, Shumeng; Lu, Qiang; Liu, Xi; Liu, Shanshan; Zhu, Hesun

2015-10-01

Osteoinductive silk/hydroxyapatite (HA) composite scaffolds for bone regeneration were prepared by combining silk with HA/silk core-shell nanoparticles. The HA/silk nanoparticles were directly dispersed in silk solution to form uniform silk/HA blend and then composite scaffolds after a freeze-drying process. The HA/silk nanoparticles uniformly distributed in silk scaffolds at nanometer scale at varying HA content up to 40%, and substantially improved the compressive strength of the scaffolds produced. Rat bone mesenchymal stem cells (rBMSCs) were cultured in these scaffolds and cell proliferation was analyzed by confocal microscopy and DNA assay. Gene expression and biochemical assays were employed to study the influence of increasing HA/silk nanoparticles on in vitro osteogenic differentiation of rBMSCs. Increasing HA/silk nanoparticles inside silk scaffolds improved the growth and osteogenic capability of rBMSCs in the absence of osteogenic growth factors, and also significantly increased the calcium and collagen I deposition. In addition, compared to silk/HA composite scaffolds containing HA aggregates, the scaffolds loaded with HA/silk nanoparticles showed remarkably higher stiffness and better osteogenic property at same HA content, implying a preferable microenvironment for rBMSCs. These results suggest that the osteogenic property as well as mechanical property of silk/HA scaffolds could be further improved through fabricating their structure and topography at nanometer scale, providing more suitable systems for bone regeneration. © 2014 Wiley Periodicals, Inc.

High strength yttria-reinforced HA scaffolds fabricated via honeycomb ceramic extrusion.

PubMed

Elbadawi, M; Shbeh, M

2018-01-01

The present study investigated the effects of hydroxyapatite (HA) reinforced with yttria on porous scaffolds fabricated via honeycomb ceramic extrusion. Yttria was selected as it has been demonstrated to toughen other ceramics. Moreover, yttria has been surmised to suppress dehydroxylation in HA, a characteristic that prefigures decomposition thereof during sintering into mechanically weaker phases. However, the compressive strength of yttria-reinforced hydroxyapatite (Y-HA) porous scaffolds has hitherto not been reported. Y-HA was synthesised by calcining a commercially available HA with 10wt% yttria at 1000°C. Y-HA was then fabricated into porous scaffolds using an in-house honeycomb extruder, and subsequently sintered at 1200 and 1250°C. The results were compared to the uncalcined as-received commercial powder (AR-HA) and calcined pure HA powder at 1000°C (C-HA). It was discovered that calcination alone caused marked improvements to the stoichiometry, thermal stability, porosity and compressive strength of scaffolds. The improvements were ascribed to the calcined powders with less susceptibility to both agglomeration and enhanced densification. Still, differences were observed between C-HA and Y-HA at 1250°C. The compressive strength increased from 105.9 to 127.3MPa, a larger microporosity was descried and the HA matrix in Y-HA was more stoichiometric. The latter was confirmed by XRD and EDS analyses. Therefore, it was concluded that the reinforcing of hydroxyapatite with yttria improved the compressive strength and suppressed dehydroxylation of porous HA scaffolds. In addition, the compressive strength achieved demonstrated great potential for load-bearing application. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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.

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

Computer-guided design, synthesis, and biological evaluation of quinoxalinebisarylureas as FLT3 inhibitors.

PubMed

Göring, Stefan; Bensinger, Dennis; Naumann, Eva C; Schmidt, Boris

2015-03-01

Activating mutations of FMS-like tyrosine kinase 3 (FLT3) are present in ∼30 % of patients with acute myeloid leukemia (AML) and are associated with poor prognosis. Point mutations in the tyrosine kinase domain (TKD) are observed as primary mutations or are acquired as secondary mutations in FLT3 with internal tandem duplications (ITDs) after treatment with tyrosine kinase inhibitors (TKIs). Although dozens of potent inhibitors against FLT3 ITD have been reported, activating TKD point mutations, especially at residues F691 and D835, remain the leading cause for therapy resistance, highlighting the consistent need for new potent inhibitors. Herein we report the identification and characterization of novel quinoxaline-based FLT3 inhibitors. We used the pharmacophore features of diverse known inhibitors as a starting point for a new optimization algorithm for type II TKIs, starting from an in silico library pharmacophore search and induced-fit docking in the known FLT3 structure. This led to the design of a set of diverse quinoxalinebisarylureas, which were profiled in an FLT3 kinase activity assay. The most promising compounds were further evaluated in a zebrafish embryo phenotype assay. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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…

Panobinostat induces apoptosis via production of reactive oxygen species and synergizes with topoisomerase inhibitors in cervical cancer cells.

PubMed

Wasim, Lubna; Chopra, Madhu

2016-12-01

Cervical cancer is the fourth major cause of cancer-related deaths in women worldwide and is the most common cancer in developing countries. Therefore, a search for novel treatment modalities is warranted. The present study is designed to investigate the effect of pan histone deacetylase inhibitor, 'panobinostat', on cervical cancer cells alone and in combination with topoisomerase inhibitors. We assessed the effect of panobinostat on two cervical cancer cell lines, HeLa and SiHa, for cell viability, apoptosis, oxidative stress and mitochondrial function using various assays. The results indicate that panobinostat reduces the viability of cervical cancer cells in a dose- and time-dependent manner; it arrests HeLa cells in G0/G1 and SiHa cells in G2/M phase of the cell cycle. Panobinostat induced apoptosis through an increase in the ROS production and the disruption of mitochondrial membrane potential. Concomitantly the expression of anti-apoptotic gene Bcl-xL was reduced, while levels of CDK inhibitor p21 and caspase-9 were increased. Panobinostat increased the acetylation of histone H3 indicating HDAC inhibition. In addition, panobinostat also showed synergistic effect with topoisomerase inhibitors mediated by increased activation of caspase-3/7 activity compared to that in cells treated with panobinostat alone. These results suggest a combination therapy using inhibitors of histone deacetylase and topoisomerase together could hold the promise for an effective targeted therapeutic strategy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Bisphosphonate Inhibitors Reveal a Large Elasticity of Plastidic Isoprenoid Synthesis Pathway in Isoprene-Emitting Hybrid Aspen1

PubMed Central

2015-01-01

Recently, a feedback inhibition of the chloroplastic 1-deoxy-d-xylulose 5-phosphate (DXP)/2-C-methyl-d-erythritol 4-phosphate (MEP) pathway of isoprenoid synthesis by end products dimethylallyl diphosphate (DMADP) and isopentenyl diphosphate (IDP) was postulated, but the extent to which DMADP and IDP can build up is not known. We used bisphosphonate inhibitors, alendronate and zoledronate, that inhibit the consumption of DMADP and IDP by prenyltransferases to gain insight into the extent of end product accumulation and possible feedback inhibition in isoprene-emitting hybrid aspen (Populus tremula × Populus tremuloides). A kinetic method based on dark release of isoprene emission at the expense of substrate pools accumulated in light was used to estimate the in vivo pool sizes of DMADP and upstream metabolites. Feeding with fosmidomycin, an inhibitor of DXP reductoisomerase, alone or in combination with bisphosphonates was used to inhibit carbon input into DXP/MEP pathway or both input and output. We observed a major increase in pathway intermediates, 3- to 4-fold, upstream of DMADP in bisphosphonate-inhibited leaves, but the DMADP pool was enhanced much less, 1.3- to 1.5-fold. In combined fosmidomycin/bisphosphonate treatment, pathway intermediates accumulated, reflecting cytosolic flux of intermediates that can be important under strong metabolic pull in physiological conditions. The data suggested that metabolites accumulated upstream of DMADP consist of phosphorylated intermediates and IDP. Slow conversion of the huge pools of intermediates to DMADP was limited by reductive energy supply. These data indicate that the DXP/MEP pathway is extremely elastic, and the presence of a significant pool of phosphorylated intermediates provides an important valve for fine tuning the pathway flux. PMID:25926480

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

PubMed

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

2017-07-21

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

Conceptualizing adverse outcome pathways for cyclooxygenase inhibitors using transcriptomic and metabolomic characterization

EPA Science Inventory

Cyclooxygenase (COX) inhibition is of concern in fish because COX inhibitors (e.g., ibuprofen) are ubiquitous in aquatic systems/fish tissues, and can disrupt synthesis of prostaglandins that modulate a variety of essential biological functions (e.g., reproduction). This study ut...

Nitric Oxide Stimulates Matrix Synthesis and Deposition by Adult Human Aortic Smooth Muscle Cells Within Three-Dimensional Cocultures

PubMed Central

Simmers, Phillip; Gishto, Arsela; Vyavahare, Narendra

2015-01-01

Vascular diseases are characterized by the over-proliferation and migration of aortic smooth muscle cells (SMCs), and degradation of extracellular matrix (ECM) within the vessel wall, leading to compromise in cell–cell and cell–matrix signaling pathways. Tissue engineering approaches to regulate SMC over-proliferation and enhance healthy ECM synthesis showed promise, but resulted in low crosslinking efficiency. Here, we report the benefits of exogenous nitric oxide (NO) cues, delivered from S-Nitrosoglutathione (GSNO), to cell proliferation and matrix deposition by adult human aortic SMCs (HA-SMCs) within three-dimensional (3D) biomimetic cocultures. A coculture platform with two adjacent, permeable 3D culture chambers was developed to enable paracrine signaling between vascular cells. HA-SMCs were cultured in these chambers within collagen hydrogels, either alone or in the presence of human aortic endothelial cells (HA-ECs) cocultures, and exogenously supplemented with varying GSNO dosages (0–100 nM) for 21 days. Results showed that EC cocultures stimulated SMC proliferation within GSNO-free cultures. With increasing GSNO concentration, HA-SMC proliferation decreased in the presence or absence of EC cocultures, while HA-EC proliferation increased. GSNO (100 nM) significantly enhanced the protein amounts synthesized by HA-SMCs, in the presence or absence of EC cocultures, while lower dosages (1–10 nM) offered marginal benefits. Multi-fold increases in the synthesis and deposition of elastin, glycosaminoglycans, hyaluronic acid, and lysyl oxidase crosslinking enzyme (LOX) were noted at higher GSNO dosages, and coculturing with ECs significantly furthered these trends. Similar increases in TIMP-1 and MMP-9 levels were noted within cocultures with increasing GSNO dosages. Such increases in matrix synthesis correlated with NO-stimulated increases in endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) expression within EC

Effectively delivering a unique hsp90 inhibitor using star polymers.

PubMed

Kim, Seong Jong; Ramsey, Deborah M; Boyer, Cyrille; Davis, Thomas P; McAlpine, Shelli R

2013-07-25

We report the synthesis of a novel heat shock protein 90 (hsp90) inhibitor conjugated to a star polymer. Using reversible addition-fragmentation chain-transfer (RAFT) polymerization, we prepared star polymers comprised of PEG attached to a predesigned functional core. The stars were cross-linked using disulfide linkers, and a tagged version of our hsp90 inhibitor was conjugated to the polymer core to generate nanoparticles (14 nM). Dynamic light scattering showed that the nanoparticles were stable in cell growth media for 5 days, and HPLC analysis of compound-release at 3 different pH values showed that release was pH dependent. Cell cytotoxicity studies and confocal microscopy verify that our hsp90 inhibitor was delivered to cells using this nanoparticle delivery system. Further, delivery of our hsp90 inhibitor using star polymer induces apoptosis by a caspase 3-dependent pathway. These studies show that we can deliver our hsp90 inhibitor effectively using star polymers, and induce apoptosis by the same pathway as the parent compound.

The efficacy of a chitin synthesis inhibitor against field populations of organophosphate-resistant Aedes aegypti in Brazil.

PubMed

Fontoura, Nathalia Giglio; Bellinato, Diogo Fernandes; Valle, Denise; Lima, José Bento Pereira

2012-05-01

The mosquito Aedes aegypti is the main focus of dengue control campaigns. Because of widespread resistance against conventional chemical insecticides, chitin synthesis inhibitors (CSIs) are considered control alternatives. We evaluated the resistance status of four Brazilian Ae. aegypti populations to both the organophosphate temephos and the pyrethroid deltamethrin, which are used in Brazil to control larvae and adults, respectively. All vector populations exhibited high levels of temephos resistance and varying rates of alterations in their susceptibility to pyrethroids. The effect of the CSI novaluron on these populations was also investigated. Novaluron was effective against all populations under laboratory conditions. Field-simulated assays with partial water replacement were conducted to evaluate novaluron persistence. Bioassays were continued until an adult emergence inhibition of at least 70% was attained. We found a residual effect of eight weeks under indoor conditions and novaluron persisted for five-six weeks in assays conducted in an external area. Our data show that novaluron is effective against the Ae. aegypti populations tested, regardless of their resistance to conventional chemical insecticides.

Insect P450 inhibitors and insecticides: challenges and opportunities.

PubMed

Feyereisen, René

2015-06-01

P450 enzymes are encoded by a large number of genes in insects, often over a hundred. They play important roles in insecticide metabolism and resistance, and growing numbers of P450 enzymes are now known to catalyse important physiological reactions, such as hormone metabolism or cuticular hydrocarbon synthesis. Ways to inhibit P450 enzymes specifically or less specifically are well understood, as P450 inhibitors are found as drugs, as fungicides, as plant growth regulators and as insecticide synergists. Yet there are no P450 inhibitors as insecticides on the market. As new modes of action are constantly needed to support insecticide resistance management, P450 inhibitors should be considered because of their high potential for insect selectivity, their well-known mechanisms of action and the increasing ease of rational design and testing. © 2014 Society of Chemical Industry.

Transport features of nano-hydroxylapatite (n-HA) embedded silicone rubber (SR) systems: influence of SR/n-HA interaction, degree of reinforcement and morphology.

PubMed

M, Bindu; G, Unnikrishnan

2017-09-27

We report the transport characteristics of silicone rubber/nano-hydroxylapatite (SR/n-HA) systems at room temperature with reference to the effects of n-HA loading, morphology and penetrant nature, using toluene, xylene, ethyl acetate and butyl acetate in the liquid phase and methanol, ethanol, 1-propanol, 2-propanol and butanol in the vapour phase as probe molecules. The interaction between the n-HA particles and SR matrix has been confirmed by FTIR analysis. As the n-HA content in the SR matrix increased, the penetrant uptake has been found to decrease. The observations have been correlated with the density and void content of the systems. Scanning electron microscopy images have been found to be complementary to the observed transport features. The reinforcement effect of n-HA particles on the SR matrix has been verified by Kraus equation. Molecular mass between the cross links has been observed to decrease with an increase in n-HA loading. The results have been compared with affine, phantom network, parallel, series and Maxwell models. The transport data have been complemented by observations on biological fluid uptake with urea, d-glucose, KI, saline water, phosphate buffer and artificial urine as the media.

Stalking influenza by vaccination with pre-fusion headless HA mini-stem.

PubMed

Valkenburg, Sophie A; Mallajosyula, V Vamsee Aditya; Li, Olive T W; Chin, Alex W H; Carnell, George; Temperton, Nigel; Varadarajan, Raghavan; Poon, Leo L M

2016-03-07

Inaccuracies in prediction of circulating viral strain genotypes and the possibility of novel reassortants causing a pandemic outbreak necessitate the development of an anti-influenza vaccine with increased breadth of protection and potential for rapid production and deployment. The hemagglutinin (HA) stem is a promising target for universal influenza vaccine as stem-specific antibodies have the potential to be broadly cross-reactive towards different HA subtypes. Here, we report the design of a bacterially expressed polypeptide that mimics a H5 HA stem by protein minimization to focus the antibody response towards the HA stem. The HA mini-stem folds as a trimer mimicking the HA prefusion conformation. It is resistant to thermal/chemical stress, and it binds to conformation-specific, HA stem-directed broadly neutralizing antibodies with high affinity. Mice vaccinated with the group 1 HA mini-stems are protected from morbidity and mortality against lethal challenge by both group 1 (H5 and H1) and group 2 (H3) influenza viruses, the first report of cross-group protection. Passive transfer of immune serum demonstrates the protection is mediated by stem-specific antibodies. Furthermore, antibodies induced by these HA stems have broad HA reactivity, yet they do not have antibody-dependent enhancement activity.

Effect of reaction solvent on hydroxyapatite synthesis in sol-gel process

NASA Astrophysics Data System (ADS)

Nazeer, Muhammad Anwaar; Yilgor, Emel; Yagci, Mustafa Baris; Unal, Ugur; Yilgor, Iskender

2017-12-01

Synthesis of hydroxyapatite (HA) through sol-gel process in different solvent systems is reported. Calcium nitrate tetrahydrate (CNTH) and diammonium hydrogen phosphate (DAHP) were used as calcium and phosphorus precursors, respectively. Three different synthesis reactions were carried out by changing the solvent media, while keeping all other process parameters constant. A measure of 0.5 M aqueous DAHP solution was used in all reactions while CNTH was dissolved in distilled water, tetrahydrofuran (THF) and N,N-dimethylformamide (DMF) at a concentration of 0.5 M. Ammonia solution (28-30%) was used to maintain the pH of the reaction mixtures in the 10-12 range. All reactions were carried out at 40 ± 2°C for 4 h. Upon completion of the reactions, products were filtered, washed and calcined at 500°C for 2 h. It was clearly demonstrated through various techniques that the dielectric constant and polarity of the solvent mixture strongly influence the chemical structure and morphological properties of calcium phosphate synthesized. Water-based reaction medium, with highest dielectric constant, mainly produced β-calcium pyrophosphate (β-CPF) with a minor amount of HA. DMF/water system yielded HA as the major phase with a very minor amount of β-CPF. THF/water solvent system with the lowest dielectric constant resulted in the formation of pure HA.

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.

N-acetylcysteine stimulates protein synthesis in enterocytes independently of glutathione synthesis.

PubMed

Yi, Dan; Hou, Yongqing; Wang, Lei; Long, Minhui; Hu, Shengdi; Mei, Huimin; Yan, Liqiong; Hu, Chien-An Andy; Wu, Guoyao

2016-02-01

Dietary supplementation with N-acetylcysteine (NAC) has been reported to improve intestinal health and treat gastrointestinal diseases. However, the underlying mechanisms are not fully understood. According to previous reports, NAC was thought to exert its effect through glutathione synthesis. This study tested the hypothesis that NAC enhances enterocyte growth and protein synthesis independently of cellular glutathione synthesis. Intestinal porcine epithelial cells were cultured for 3 days in Dulbecco's modified Eagle medium containing 0 or 100 μM NAC. To determine a possible role for GSH (the reduced form of glutathione) in mediating the effect of NAC on cell growth and protein synthesis, additional experiments were conducted using culture medium containing 100 μM GSH, 100 μM GSH ethyl ester (GSHee), diethylmaleate (a GSH-depletion agent; 10 μM), or a GSH-synthesis inhibitor (buthionine sulfoximine, BSO; 20 μM). NAC increased cell proliferation, GSH concentration, and protein synthesis, while inhibiting proteolysis. GSHee enhanced cell proliferation and GSH concentration without affecting protein synthesis but inhibited proteolysis. Conversely, BSO or diethylmaleate reduced cell proliferation and GSH concentration without affecting protein synthesis, while promoting protein degradation. At the signaling level, NAC augmented the protein abundance of total mTOR, phosphorylated mTOR, and phosphorylated 70S6 kinase as well as mRNA levels for mTOR and p70S6 kinase in IPEC-1 cells. Collectively, these results indicate that NAC upregulates expression of mTOR signaling proteins to stimulate protein synthesis in enterocytes independently of GSH generation. Our findings provide a hitherto unrecognized biochemical mechanism for beneficial effects of NAC in intestinal cells.

Serum Inter–α-Trypsin Inhibitor and Matrix Hyaluronan Promote Angiogenesis in Fibrotic Lung Injury

PubMed Central

Garantziotis, Stavros; Zudaire, Enrique; Trempus, Carol S.; Hollingsworth, John W.; Jiang, Dianhua; Lancaster, Lisa H.; Richardson, Elizabeth; Zhuo, Lisheng; Cuttitta, Frank; Brown, Kevin K.; Noble, Paul W.; Kimata, Koji; Schwartz, David A.

2008-01-01

Rationale: The etiology and pathogenesis of angiogenesis in idiopathic pulmonary fibrosis (IPF) is poorly understood. Inter-α-trypsin inhibitor (IaI) is a serum protein that can bind to hyaluronan (HA) and may contribute to the angiogenic response to tissue injury. Objectives: To determine whether IaI promotes HA-mediated angiogenesis in tissue injury. Methods: An examination was undertaken of angiogenesis in IaI-sufficient and -deficient mice in the bleomycin model of pulmonary fibrosis and in angiogenesis assays in vivo and in vitro. IaI and HA in patients with IPF were examined. Measurements and Main Results: IaI significantly enhances the angiogenic response to short-fragment HA in vivo and in vitro. lal deficiency Ieads to decreased angiogenesis in the matrigel model, and decreases lung angiogenesis after bleomycin exposure in mice. IaI is found in fibroblastic foci in IPF, where it colocalizes with HA. The colocalization is particularly strong in vascular areas around fibroblastic foci. Serum levels of IaI and HA are significantly elevated in patients with IPF compared with control subjects. High serum IaI and HA levels are associated with decreased lung diffusing capacity, but not FVC. Conclusions: Our findings indicate that serum IaI interacts with HA, and promotes angiogenesis in lung injury. IaI appears to contribute to the vascular response to lung injury and may lead to aberrant angiogenesis. Clinical trial registered with www.clinicaltrials.gov (NCT00016627). PMID:18703791

Effect of nitrification inhibitors (DMPP and 3MP+TZ) on soil nitrous oxide emissions from a sub-tropical vegetable production system in Queensland, Australia

NASA Astrophysics Data System (ADS)

Scheer, Clemens; Deuter, Peter; Firrell, Mary; Rowlings, David; Grace, Peter

2015-04-01

The use of nitrification inhibitors, in combination with ammonium based fertilisers, has been promoted recently as an effective method to reduce nitrous oxide (N2O) emissions from fertilised agricultural fields, whilst increasing yield and nitrogen use efficiency. Vegetable cropping systems are often characterised by high inputs of nitrogen fertiliser and consequently elevated emissions of nitrous oxide (N2O) can be expected. However, to date only limited data is available on the use of nitrification inhibitors in sub-tropical vegetable systems. A field experiment investigated the effect of the nitrification inhibitors (DMPP & 3MP+TZ) on N2O emissions and yield from a typical vegetable production system in sub-tropical Australia. Soil N2O fluxes were monitored continuously over an entire year with a fully automated system. Measurements were taken from three subplots for each treatment within a randomized complete blocks design. There was a significant inhibition effect of DMPP and 3MP+TZ on N2O emissions and soil mineral N content directly following the application of the fertiliser over the vegetable cropping phase. However this mitigation was offset by elevated N2O emissions from the inhibitor treatments over the post-harvest fallow period. Cumulative annual N2O emissions amounted to 1.22 kg-N/ha, 1.16 kg-N/ha, 1.50 kg-N/ha and 0.86 kg-N/ha in the conventional fertiliser (CONV), the DMPP treatment, the 3MP+TZ treatment and the zero fertiliser (0N) respectively. Corresponding fertiliser induced emission factors (EFs) were low with only 0.09 - 0.20% of the total applied fertiliser lost as N2O. There was no significant effect of the nitrification inhibitors on yield compared to the CONV treatment for the three vegetable crops (green beans, broccoli, lettuce) grown over the experimental period. This study highlights that N2O emissions from such vegetable cropping system are primarily controlled by post-harvest emissions following the incorporation of vegetable crop

Inhibitors of ceramide de novo biosynthesis rescue damages induced by cigarette smoke in airways epithelia.

PubMed

Zulueta, Aida; Caretti, Anna; Campisi, Giuseppe Matteo; Brizzolari, Andrea; Abad, Jose Luis; Paroni, Rita; Signorelli, Paola; Ghidoni, Riccardo

2017-07-01

Exposure to cigarette smoke represents the most important risk factor for the development of chronic obstructive pulmonary disease (COPD). COPD is characterized by chronic inflammation of the airways, imbalance of proteolytic activity resulting in the destruction of lung parenchyma, alveolar hypoxia, oxidative stress, and apoptosis. Sphingolipids are structural membrane components whose metabolism is altered during stress. Known as apoptosis and inflammation inducer, the sphingolipid ceramide was found to accumulate in COPD airways and its plasma concentration increased as well. The present study investigates the role of sphingolipids in the cigarette smoke-induced damage of human airway epithelial cells. Lung epithelial cells were pre-treated with sphingolipid synthesis inhibitors (myriocin or XM462) and then exposed to a mixture of nicotine, acrolein, formaldehyde, and acetaldehyde, the major toxic cigarette smoke components. The inflammatory and proteolytic responses were investigated by analysis of the mRNA expression (RT-PCR) of cytokines IL-1β and IL-8, and matrix metalloproteinase-9 and of the protein expression (ELISA) of IL-8. Ceramide intracellular amounts were measured by LC-MS technique. Ferric-reducing antioxidant power test and superoxide anion radical scavenging activity assay were used to assess the antioxidant power of the inhibitors of ceramide synthesis. We here show that ceramide synthesis is enhanced under treatment with a cigarette smoke mixture correlating with increased expression of inflammatory cytokines and matrix metalloproteinase 9. The use of inhibitors of ceramide synthesis protected from smoke induced damages such as inflammation, oxidative stress, and proteolytic imbalance in airways epithelia.

Synthesis and structure-activity relationships of imidazo[1,2-a]pyrimidin-5(1H)-ones as a novel series of beta isoform selective phosphatidylinositol 3-kinase inhibitors.

PubMed

Lin, Hong; Erhard, Karl; Hardwicke, Mary Ann; Luengo, Juan I; Mack, James F; McSurdy-Freed, Jeanelle; Plant, Ramona; Raha, Kaushik; Rominger, Cynthia M; Sanchez, Robert M; Schaber, Michael D; Schulz, Mark J; Spengler, Michael D; Tedesco, Rosanna; Xie, Ren; Zeng, Jin J; Rivero, Ralph A

2012-03-15

A series of PI3K-beta selective inhibitors, imidazo[1,2-a]-pyrimidin-5(1H)-ones, has been rationally designed based on the docking model of the more potent R enantiomer of TGX-221, identified by a chiral separation, in a PI3K-beta homology model. Synthesis and SAR of this novel chemotype are described. Several compounds in the series demonstrated potent growth inhibition in a PTEN-deficient breast cancer cell line MDA-MB-468 under anchorage independent conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preparation, optimization and property of PVA-HA/PAA composite hydrogel.

PubMed

Chen, Kai; Liu, Jinlong; Yang, Xuehui; Zhang, Dekun

2017-09-01

PVA-HA/PAA composite hydrogel is prepared by freezing-thawing, PEG dehydration and annealing method. Orthogonal design method is used to choose the optimization combination. Results showed that HA and PVA have the maximum effect on water content. PVA and freezing-thawing cycles have the maximum effect on creep resistance and stress relaxation rate of hydrogel. Annealing temperature and freezing-thawing cycles have the maximum effect on compressive elastic modulus of hydrogel. Comparing with the water content and mechanical properties of 16 kinds of combination, PVA-HA/PAA composite hydrogel with freezing-thawing cycles of 3, annealing temperature of 120°C, PVA of 16%, HA of 2%, PAA of 4% has the optimization comprehensive properties. PVA-HA/PAA composite hydrogel has a porous network structure. There are some interactions between PVA, HA and PAA in hydrogel and the properties of hydrogel are strengthened. The annealing treatment improves the crystalline and crosslinking of hydrogel. Therefore, the annealing PVA-HA/PAA composite hydrogel has good thermostability, strength and mechanical properties. It also has good lubrication property and its friction coefficient is relative low. Copyright © 2017 Elsevier B.V. All rights reserved.

Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts

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

Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo

Highlights: Black-Right-Pointing-Pointer We identify a function of the YIGSR peptide to enhance collagen synthesis in Hs27. Black-Right-Pointing-Pointer YIGSR peptide enhanced collagen type 1 synthesis both of gene and protein levels. Black-Right-Pointing-Pointer There were no changes in cell proliferation and MMP-1 level in YIGSR treatment. Black-Right-Pointing-Pointer The YIGSR effect on collagen synthesis mediated activation of FAK, pyk2 and ERK. Black-Right-Pointing-Pointer The YIGSR-induced FAK and ERK activation was modulated by FAK and MEK inhibitors. -- Abstract: The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin,more » respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929-933 sequence of the {beta}1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67 kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong

[Construction of porous hydroxyapatite (HA) block loaded with cultured chondrocytes].

PubMed

Yan, M; Dang, G

1999-07-01

To construct a kind of bone healing enhancing implant with cultured chondrocytes bound to hydroxyapatite (HA). Chondrocytes were obtained from the costicartilage of rat and were cultured on the porous HA blocks, 3 mm x 3 mm x 4 mm size, for three and seven days. Scanning electron micrograph was taken to show whether the cells grew outside and inside the pore of HA block. The cells cultured on tiny glass sheet for 2 days were used to prove where the cells come from by in situ hybridization technique with alpha1 (II) cDNA probe. Scanning electron micrographs showed that the pores of the HA surface and inside of the blocks are filled with cultured cells, especially the longer cultured block. The cells were chondrocytes confirmed by in situ hybridization. The porous HA can be used as cell cultured substrate and chondrocyte can adhere and proliferate inside the porous HA block.

Synthesis and investigation of dihydroxychalcones as calpain and cathepsin inhibitors.

PubMed

Baek, Kyung Hye; Karki, Radha; Lee, Eung-Seok; Na, Younghwa; Kwon, Youngjoo

2013-12-01

In order to identify potential calpain and cathepsin inhibitors we prepared 12 dihydroxychalcone analogues and tested their ability to inhibit μ-calpain, m-calpain, cathepsins B and L. In the calpain inhibition test, compound 10 exhibited the most active inhibitory activity against m-calpain with an IC50 value of 25.25±0.901μM. With respect to inhibition of cathepsins B and L, compound 13 exhibited the most potent inhibitory activity on cathepsin L and moderate inhibitory activity on cathepsin B with IC50 values of 2.80±0.100 and 11.47±0.087μM, respectively. Our results suggest the possibility of developing dual calpain and cathepsin inhibitors by properly modulating structures and/or combining the essential aspects of the functional group effective for specific calpain and cathepsin inhibition. Copyright © 2013 Elsevier Inc. All rights reserved.

The Efficacy and Safety of HA IDF Plus (with Lidocaine) Versus HA IDF (Without Lidocaine) in Nasolabial Folds Injection: A Randomized, Multicenter, Double-Blind, Split-Face Study.

PubMed

Lee, Jong-Hun; Kim, Seok-Hwan; Park, Eun-Soo

2017-04-01

Injection-related pain of dermal fillers is a consistent and bothersome problem for patients undergoing soft tissue augmentation. Reducing the pain could improve overall patient satisfaction. The purpose of this study was to compare the pain relief, efficacy, and safety of HA IDF plus containing lidocaine with HA IDF without lidocaine during correction of nasolabial folds (NLFs). Sixty-two subjects were enrolled in a randomized, multicenter, double-blind, split-face study of HA IDF plus and HA IDF for NLF correction. For split-face study, HA IDF plus was injected to one side of NLF, and HA IDF was injected to the other side. The first evaluation variable was the injection site pain measured using a 100-mm visual analogue scale (VAS). The second evaluation variables included the global aesthetic improvement scale, wrinkle severity rating scale, and adverse events. Immediately after injection, 91.94% of subjects experienced at least 10 mm decrease in VAS scores at the side injected with HA IDF plus compared with HA IDF, and the rate of subjects is statistically significant. The two fillers were not significantly different in safety profile or wrinkle correction during the follow-up visit. HA IDF plus significantly reduced the injection-related pain during NLFs correction compared with HA IDF without altering clinical outcomes or safety. Both HA IDF plus and HA IDF were considerably tolerated and most adverse reactions were mild and transient. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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

The role of peroxisome proliferator-activated receptor-{beta}/{delta} in epidermal growth factor-induced HaCaT cell proliferation

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

Liang Pengfei; Jiang Bimei; Yang Xinghua

2008-10-15

Epidermal growth factor (EGF) has been shown to be a potent mitogen for epidermal cells both in vitro and in vivo, thus contributing to the development of an organism. It has recently become clear that peroxisome proliferator-activated receptor-{beta}/{delta} (PPAR{beta}/{delta}) expression and activation is involved in the cell proliferation. However, little is known about the role of PPAR{beta}/{delta} in EGF-induced proliferation of HaCaT keratinocytes. In this study, HaCaT cells were cultured in the presence and absence of EGF and we identified that EGF induced an increase of PPAR{beta}/{delta} mRNA and protein level expression in time-dependent and dose-dependent manner, and AG1487, anmore » EGF receptor (EGFR) special inhibitor, caused attenuation of PPAR{beta}/{delta} protein expression. Electrophoretic mobility shift assay (EMSA) revealed that EGF significantly increased PPAR{beta}/{delta} binding activity in HaCaT keratinocytes. Antisense phosphorothioate oligonucleotides (asODNs) against PPAR{beta}/{delta} caused selectively inhibition of PPAR{beta}/{delta} protein content induced by EGF and significantly attenuated EGF-mediated cell proliferation. Treatment of the cells with L165041, a specific synthetic ligand for PPAR{beta}/{delta}, significantly enhanced EGF-mediated cell proliferation. Finally, c-Jun ablation inhibited PPAR{beta}/{delta} up-regulation induced by EGF, and chromatin immunoprecipitation (ChIP) showed that c-Jun bound to the PPAR{beta}/{delta} promoter and the binding increased in EGF-stimulated cells. These results demonstrate that EGF induces PPAR{beta}/{delta} expression in a c-Jun-dependent manner and PPAR{beta}/{delta} plays a vital role in EGF-stimulated proliferation of HaCaT cells.« less

Hydrocortisone and triiodothyronine regulate hyaluronate synthesis in a tissue-engineered human dermal equivalent through independent pathways.

PubMed

Deshpande, Madhura; Papp, Suzanne; Schaffer, Lana; Pouyani, Tara

2015-02-01

Hydrocortisone (HC) and triiodothyronine (T3) have both been shown to be capable of independently inhibiting hyaluronate (HA, hyaluronic acid) synthesis in a self-assembled human dermal equivalent (human dermal matrix). We sought to investigate the action of these two hormones in concert on extracellular matrix formation and HA inhibition in the tissue engineered human dermal matrix. To this end, neonatal human dermal fibroblasts were cultured in defined serum-free medium for 21 days in the presence of each hormone alone, or in combination, in varying concentrations. Through a process of self-assembly, a substantial dermal extracellular matrix formed that was characterized. The results of these studies demonstrate that combinations of the hormones T3 and hydrocortisone showed significantly higher levels of hyaluronate inhibition as compared to each hormone alone in the human dermal matrix. In order to gain preliminary insight into the genes regulating HA synthesis in this system, a differential gene array analysis was conducted in which the construct prepared in the presence of 200 μg/mL HC and 0.2 nM T3 was compared to the normal construct (0.4 μg/mL HC and 20 pM T3). Using a GLYCOv4 gene chip containing approximately 1260 human genes, we observed differential expression of 131 genes. These data suggest that when these two hormones are used in concert a different mechanism of inhibition prevails and a combination of degradation and inhibition of HA synthesis may be responsible for HA regulation in the human dermal matrix. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Discovery of DF-461, a Potent Squalene Synthase Inhibitor

PubMed Central

2013-01-01

We report the development of a new trifluoromethyltriazolobenzoxazepine series of squalene synthase inhibitors. Structure–activity studies and pharmacokinetics optimization on this series led to the identification of compound 23 (DF-461), which exhibited potent squalene synthase inhibitory activity, high hepatic selectivity, excellent rat hepatic cholesterol synthesis inhibitory activity, and plasma lipid lowering efficacy in nonrodent repeated dose studies. PMID:24900587

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

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

Pecic, Stevan; Pakhomova, Svetlana; Newcomer, Marcia E.

2013-09-27

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

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

Caveolin-1 down-regulation is required for Wnt5a-Frizzled 2 signalling in Ha-RasV12 -induced cell transformation.

PubMed

Lin, Hsiu-Kuan; Lin, Hsi-Hui; Chiou, Yu-Wei; Wu, Ching-Lung; Chiu, Wen-Tai; Tang, Ming-Jer

2018-05-01

Caveolin-1 (Cav1) is down-regulated during MK4 (MDCK cells harbouring inducible Ha-Ras V12 gene) transformation by Ha-Ras V12 . Cav1 overexpression abrogates the Ha-Ras V12 -driven transformation of MK4 cells; however, the targeted down-regulation of Cav1 is not sufficient to mimic this transformation. Cav1-silenced cells, including MK4/shCav1 cells and MDCK/shCav1 cells, showed an increased cell area and discontinuous junction-related proteins staining. Cellular and mechanical transformations were completed when MDCK/shCav1 cells were treated with medium conditioned by MK4 cells treated with IPTG (MK4+I-CM) but not with medium conditioned by MK4 cells. Nanoparticle tracking analysis showed that Ha-Ras V12 -inducing MK4 cells increased exosome-like microvesicles release compared with their normal counterparts. The cellular and mechanical transformation activities of MK4+I-CM were abolished after heat treatment and exosome depletion and were copied by exosomes derived from MK4+I-CM (MK4+I-EXs). Wnt5a, a downstream product of Ha-Ras V12 , was markedly secreted by MK4+I-CM and MK4+I-EXs. Suppression of Wnt5a expression and secretion using the porcupine inhibitor C59 or Wnt5a siRNA inhibited the Ha-Ras V12 - and MK4+I-CM-induced transformation of MK4 cells and MDCK/shCav1 cells, respectively. Cav1 down-regulation, either by Ha-Ras V12 or targeted shRNA, increased frizzled-2 (Fzd2) protein levels without affecting its mRNA levels, suggesting a novel role of Cav1 in negatively regulating Fzd2 expression. Additionally, silencing Cav1 facilitated the internalization of MK4+I-EXs in MDCK cells. These data suggest that Cav1-dependent repression of Fzd2 and exosome uptake is potentially relevant to its antitransformation activity, which hinders the activation of Ha-Ras V12 -Wnt5a-Stat3 pathway. Altogether, these results suggest that both decreasing Cav1 and increasing exosomal Wnt5a must be implemented during Ha-Ras V12 -driven cell transformation. © 2018 The Authors

Structure-Based Design of Novel HIV-1 Protease Inhibitors to Combat Drug Resistance

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

Ghosh,A.; Sridhar, P.; Leshchenko, S.

2006-01-01

Structure-based design and synthesis of novel HIV protease inhibitors are described. The inhibitors are designed specifically to interact with the backbone of HIV protease active site to combat drug resistance. Inhibitor 3 has exhibited exceedingly potent enzyme inhibitory and antiviral potency. Furthermore, this inhibitor maintains impressive potency against a wide spectrum of HIV including a variety of multi-PI-resistant clinical strains. The inhibitors incorporated a stereochemically defined 5-hexahydrocyclopenta[b]furanyl urethane as the P2-ligand into the (R)-(hydroxyethylamino)sulfonamide isostere. Optically active (3aS,5R,6aR)-5-hydroxy-hexahydrocyclopenta[b]furan was prepared by an enzymatic asymmetrization of meso-diacetate with acetyl cholinesterase, radical cyclization, and Lewis acid-catalyzed anomeric reduction as the key steps.more » A protein-ligand X-ray crystal structure of inhibitor 3-bound HIV-1 protease (1.35 Angstroms resolution) revealed extensive interactions in the HIV protease active site including strong hydrogen bonding interactions with the backbone. This design strategy may lead to novel inhibitors that can combat drug resistance.« less

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

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

PubMed

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

2007-01-01

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

Surface characterization of colloidal-sol gel derived biphasic HA/FA coatings.

PubMed

Cheng, Kui; Zhang, Sam; Weng, Wenjian

2007-10-01

Hydroxyapatite (HA) powders are ultrasonically dispersed in the precursor of fluoridated hydroxyapatite (FHA) or fluorapatite (FA) to form a "colloidal sol". HA/FA biphasic coatings are prepared on Ti6Al4V substrate via dip coating, 150 degrees C drying and 600 degrees C firing. The coatings show homogenous distribution of HA particles in the FA matrix. The relative phase proportion can be tailored by the amount of HA in the colloidal sol. The surfaces of the coatings consist of two kinds of distinct domains: HA and FA, resulting in a compositionally heterogeneous surface. The biphasic coating surface becomes increasingly rougher with HA powders, from around 200 nm of pure FA to 400-600 nm in Ra of biphasic coatings. The rougher biphasic HA/FA surfaces with chemically controllable domains will favor cell attachment, apatite layer deposition and necessary dissolution in clinical applications.

Hyaluronan synthesis in cultured tobacco cells (BY-2) expressing a chlorovirus enzyme: cytological studies.

PubMed

Rakkhumkaew, Numfon; Shibatani, Shigeo; Kawasaki, Takeru; Fujie, Makoto; Yamada, Takashi

2013-04-01

Extraction of hyaluronan from animals or microbial fermentation has risks including contamination with pathogens and microbial toxins. In this work, tobacco cultured-cells (BY-2) were successfully transformed with a chloroviral hyaluronan synthase (cvHAS) gene to produce hyaluronan. Cytological studies revealed accumulation of HA on the cells, and also in subcellular fractions (protoplasts, miniplasts, vacuoplasts, and vacuoles). Transgenic BY-2 cells harboring a vSPO-cvHAS construct containing the vacuolar targeting signal of sporamin connected to the N-terminus of cvHAS accumulated significant amounts of HA in vacuoles. These results suggested that cvHAS successfully functions on the vacuolar membrane and synthesizes/transports HA into vacuoles. Efficient synthesis of HA using this system provides a new method for practical production of HA. Copyright © 2012 Wiley Periodicals, Inc.

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

Structure-activity relationships of 3-O-β-chacotriosyl oleanane-type triterpenoids as potential H5N1 entry inhibitors.

PubMed

Song, Gaopeng; Shen, Xintian; Li, Sumei; Li, Yibin; Si, Hongzong; Fan, Jihong; Li, Junhua; Gao, Erqiang; Liu, Shuwen

2016-08-25

A series of 3-O-β-chacotriosyl oleanolic acid analogs have been designed, synthesized and evaluated as H5N1 entry inhibitors based on a small molecule inhibitor saponin 1 previously discovered by us. Detailed structure-activity relationships (SARs) studies on the aglycone of compound 1 indicated that the subtle modification of oleanolic acid as an aglycon has key influences on the antiviral activity. These results suggested that either the introduction of a disubstituted amide structure at the 17-COOH of OA or alteration of the C-3 configuration of OA from 3β-to 3α-forms can significantly improve the selective index while maintaining their antiviral activities in vitro. Compound 8 was selected for further mechanistic study because of its distinguished inhibition activity and good selective index. Molecular simulation study and surface plasmon resonance analysis confirmed that compound 8 stabilized HA2 subunit of hemagglutinin (HA) by binding with amino acid residues LYS-26, ASN-53, ASN-27 and ASN-50, therefore may prevent HA from conformational rearranging, which is a critical step for viral entry. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Trichonomas vaginalis metalloproteinase induces apoptosis of SiHa cells through disrupting the Mcl-1/Bim and Bcl-xL/Bim complexes.

PubMed

Quan, Juan-Hua; Kang, Byung-Hun; Cha, Guang-Ho; Zhou, Wei; Koh, Young-Bok; Yang, Jung-Bo; Yoo, Heon-Jong; Lee, Min-A; Ryu, Jae-Sook; Noh, Heung-Tae; Kwon, Jaeyul; Lee, Young-Ha

2014-01-01

To elucidate the roles of metalloproteinases and the Bcl-2 family of proteins in Trichovaginalis. vaginalis-induced apoptosis in human cervical cancer cells (SiHa cells) and vaginal epithelial cells (MS74 cells), SiHa cells and MS74 cells were incubated with live T. vaginalis, T. vaginalis excretory and secretory products (ESP), and T. vaginalis lysates, either with or without the specific metalloproteinase inhibitor 1,10-phenanthroline (1,10-PT), and examined apoptotic events and Bcl-2 signaling. The live T. vaginalis and the T. vaginalis ESP induced the release of cytochrome c into the cytosol, the activation of caspase-3 and caspase-9, and the cleavage of PARP. Additionally, the live T. vaginalis, but not the T. vaginalis lysate, induced the cleavage of the proapoptotic Bim protein. The live T. vaginalis and the T. vaginalis ESP, but not the T. vaginalis lysate, induced the dose-dependent cleavage of the antiapoptotic Bcl-xL and Mcl-1 proteins and decreased the association levels of Bcl-xL/Bim and Mcl-1/Bim complexes. We performed gelatin zymography and casein-hydrolysis assays on the live T. vaginalis and the T. vaginalis ESP to identify the apoptosis-inducing factor. Both the live T. vaginalis and the ESP contained high levels of metalloproteinases, of which activities were significantly inhibited by 1,10-PT treatment. Furthermore, the 1,10-PT blocked the cleavage of Bcl-xL, Mcl-1, PARP, caspase-3, and caspase-9, as well as the release of cytochrome c into the cytosol, and it significantly increased the association levels of the Bcl-xL/Bim and Mcl-1/Bim protein complexes, returning them to normal levels. Our results demonstrate that T. vaginalis induces mitochondria-dependent apoptosis in SiHa cells through the dissociation of Bcl-xL/Bim and Mcl-1/Bim complexes and that the apoptosis is blocked by the metalloproteinase inhibitor 1,10-PT. These results expand our understanding of the role of metalloproteinases in T. vaginalis-induced apoptosis and the signaling

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

Combination of Pim kinase inhibitor SGI-1776 and bendamustine in B-cell lymphoma.

PubMed

Yang, Qingshan; Chen, Lisa S; Neelapu, Sattva S; Gandhi, Varsha

2013-09-01

SGI-1776 is a small-molecule Pim kinase inhibitor that primarily targets c-MYC-driven transcription and cap-dependent translation in mantle cell lymphoma (MCL) cells. Bendamustine is an alkylating chemotherapeutic agent approved for use in B-cell lymphoma that is known to induce DNA damage and initiate response to repair. Our studies were conducted in MCL cell lines JeKo-1 and Mino, as well as primary B-cell lymphoma samples of MCL and splenic marginal zone lymphoma (SMZL), where we treated cells with SGI-1776 and bendamustine. We measured levels of cellular apoptosis, macromolecule synthesis inhibition, and DNA damage induced by drug treatments. Both SGI-1776 and bendamustine effectively induced apoptosis as single agents, and when used in combination, an additive effect in cell killing was observed in MCL cell lines JeKo-1 and Mino, as well as in MCL and SMZL primary cells. As expected, SGI-1776 was effective in inducing a decrease of global RNA and protein synthesis, and bendamustine significantly inhibited DNA synthesis and generated a DNA damage response. When used in combination, the effects were intensified in DNA, RNA, and protein synthesis inhibition compared with single-agent treatments. These data provide a foundation and suggest the feasibility of using Pim kinase inhibitors in combination with chemotherapeutic agents such as bendamustine in B-cell lymphoma. Copyright © 2013 Elsevier Inc. All rights reserved.

Developing Inhibitors of Translesion DNA Synthesis as Therapeutic Agents against Lung Cancer

DTIC Science & Technology

2015-12-01

normal DNA synthesis. In contrast, pol eta shows a combination of high efficiency and low fidelity when replicating 8-oxo-G. These combined properties...are consistent with a pro- mutagenic role for pol eta when replicating this DNA lesion under cellular conditions. Studies with modified nucleotide...analogs indicate that pol eta relies heavily on hydrogen-bonding interactions during normal and translesion synthesis. However, some nucleobase

Precision Landing and Hazard Avoidance (PL&HA) Domain

NASA Technical Reports Server (NTRS)

Robertson, Edward A.; Carson, John M., III

2016-01-01

The Precision Landing and Hazard Avoidance (PL&HA) domain addresses the development, integration, testing, and spaceflight infusion of sensing, processing, and GN&C (Guidance, Navigation and Control) functions critical to the success and safety of future human and robotic exploration missions. PL&HA sensors also have applications to other mission events, such as rendezvous and docking.

Cell-Free, De Nova Synthesis of Poliovirus

NASA Astrophysics Data System (ADS)

Molla, Akhteruzzaman; Paul, Aniko V.; Wimmer, Eckard

1991-12-01

Cell-free translation of poliovirus RNA in an extract of uninfected human (HeLa) cells yielded viral proteins through proteolysis of the polyprotein. In the extract, newly synthesized proteins catalyzed poliovirus-specific RNA synthesis, and formed infectious poliovirus de novo. Newly formed virions were neutralized by type-specific antiserum, and infection of human cells with them was prevented by poliovirus receptor-specific antibodies. Poliovirus synthesis was increased nearly 70-fold when nucleoside triphosphates were added, but it was abolished in the presence of inhibitors of translation or viral genome replication. The ability to conduct cell-free synthesis of poliovirus will aid in the study of picornavirus proliferation and in the search for the control of picornaviral disease.

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.

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

Promotion of PDT efficacy by HA14-1

NASA Astrophysics Data System (ADS)

Kessel, David; Price, Michael; Haagenson, Kelly

2008-02-01

Photodynamic therapy (PDT) can target the members of the Bcl-2 family that protect cells from the initiation of apoptosis, a well-known death pathway. We examined the ability of HA14-1, a non-peptidic Bcl-2/Bcl-xL antagonist, to promote the efficacy of PDT. The photosensitizer was the porphycene CPO that causes photodamage to Bcl-2 located in the endoplasmic reticulum. Using low PDT doses together with LD5-20 concentrations of HA14-1, we found a marked synergistic effect. These results indicate that such an effect occurs when PDT is coupled with pharmacologic suppression of Bcl-2 function. HA14-1 is an unstable compound that decomposes in aqueous solution. This resulted in a rapid (~60 sec) burst of fluorescence that closely mimicked the properties of many fluorescent probes, but was traced to an effect produced when HA14-1 contacts serum proteins. Other Bcl-2 antagonists that do not produce any intrinsic fluorescence also promoted PDT efficacy. Moreover, briefly storing HA14-1 in aqueous medium until the fluorescent burst is over does not inhibit a subsequent synergistic promotion of PDT efficacy. We conclude that Bcl-2 antagonists can promote the efficacy of low-dose PDT in a manner unrelated to ROS production. The most likely explanation is an enhanced loss of anti-apoptotic Bcl-2 family function such that a threshold for initiation of apoptosis is crossed.

Synthesis of [{sup 18}F]Ro41-0960, a potent COMT inhibitor, for use in vivo mapping with PET

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

Ding, Y.S.; Sugano, Y.; Gatley, S.J.

1995-05-01

Catechol-O-methyltransferase (COMPT; EC 2.1.1.6) is one of the two major enzymes which metabolize the catecholamine neurotransmitters. It is distributed throughout the body and brain and is elevated in breast cancer tissue when it plays a role in estrogen metabolism. It is also an important molecular target in the development of drugs to treat Parkinson`s disease (PD). Because COMT regulates the concentration of important neurotransmitter amines such as dopamine, there is speculation that abnormalities in its activity may be associated with neurological, and psychiatric disorders. Ro41-9060(3,4-dihydroxy-5-nitro-2{prime}-fluorobenzophenone) is a potent, fluorine containing COMT inhibitor which has been reported to cross the bloodmore » brain barrier. It is structurally similar to Ro40-7592 which is currently undergoing clinical trials in PD. We report the synthesis of [{sup 18}F]Ro41-0960, for investigation for mapping COMT and for studies of COMT drugs. [{sup 18}F]Ro41-0960 was synthesized by the nucleophilic aromatic substitution reaction with NCA [{sup 18}F] fluoride on a protected precursor (prepared via a five-step synthesis) followed by hydrolysis with HBr (synthesis time of 100 min; radiochemical yield of 5-7% (EOB)). Though Ro41-0960 has been reported to cross the blood brain barrier, PET studies in baboon demonstrated that an almost complete absence of the drug from the brain both at tracer doses and with the addition of unlabeled drug (1.5 mg/kg) at all times through a 90 min experimental interval. The plasma to brain ratios of F-18 average about 40:1. However, high uptake was observed in the kidneys and in other organs which are known to have high COMT. Studies in mice showed that at 30 min after injection of tracer, F-18 in kidneys was largely as [{sup 18}F]Ro-41-0960 and that it could be displaced with unlabeled Ro41-0960. These studies provide the first example of a positron emitter labeled COMT radiotracer.« less

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.

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

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

PubMed

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

2016-04-01

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

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

Simultaneous Hypoxia and Low Extracellular pH Suppress Overall Metabolic Rate and Protein Synthesis In Vitro.

PubMed

Sørensen, Brita Singers; Busk, Morten; Overgaard, Jens; Horsman, Michael R; Alsner, Jan

2015-01-01

The tumor microenvironment is characterized by regions of hypoxia and acidosis which are linked to poor prognosis. This occurs due to an aberrant vasculature as well as high rates of glycolysis and lactate production in tumor cells even in the presence of oxygen (the Warburg effect), which weakens the spatial linkage between hypoxia and acidosis. Five different human squamous cell carcinoma cell lines (SiHa, FaDuDD, UTSCC5, UTSCC14 and UTSCC15) were treated with hypoxia, acidosis (pH 6.3), or a combination, and gene expression analyzed using microarray. SiHa and FaDuDD were chosen for further characterization of cell energetics and protein synthesis. Total cellular ATP turnover and relative glycolytic dependency was determined by simultaneous measurements of oxygen consumption and lactate synthesis rates and total protein synthesis was determined by autoradiographic quantification of the incorporation of 35S-labelled methionine and cysteine into protein. Microarray analysis allowed differentiation between genes induced at low oxygen only at normal extracellular pH (pHe), genes induced at low oxygen at both normal and low pHe, and genes induced at low pHe independent of oxygen concentration. Several genes were found to be upregulated by acidosis independent of oxygenation. Acidosis resulted in a more wide-scale change in gene expression profiles than hypoxia including upregulation of genes involved in the translation process, for example Eukaryotic translation initiation factor 4A, isoform 2 (EIF4A2), and Ribosomal protein L37 (RPL37). Acidosis suppressed overall ATP turnover and protein synthesis by 50%. Protein synthesis, but not total ATP production, was also suppressed under hypoxic conditions. A dramatic decrease in ATP turnover (SiHa) and protein synthesis (both cell lines) was observed when hypoxia and low pHe were combined. We demonstrate here that the influence of hypoxia and acidosis causes different responses, both in gene expression and in de novo

Tissue Inhibitor of Metalloproteinase-2 Suppresses Collagen Synthesis in Cultured Keloid Fibroblasts

PubMed Central

Dohi, Teruyuki; Aoki, Masayo; Ogawa, Rei; Akaishi, Satoshi; Shimada, Takashi; Okada, Takashi; Hyakusoku, Hiko

2015-01-01

Background: Keloids are defined as a kind of dermal fibroproliferative disorder resulting from the accumulation of collagen. In the remodeling of extracellular matrix, the balance between matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs) is as critical as the proper production of extracellular matrix. We investigate the role of TIMPs and MMPs in the pathogenesis of keloids and examine the therapeutic potential of TIMP-2. Methods: The expression of TIMPs and MMPs in most inflamed parts of cultured keloid fibroblasts (KFs) and peripheral normal skin fibroblasts (PNFs) in the same individuals and the reactivity of KFs to cyclic mechanical stretch were analyzed by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (n = 7). To evaluate the effect of treating KFs with TIMP-2, collagen synthesis was investigated by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, and microscopic analysis was used to examine the treatment effects of TIMP-2 on ex vivo cultures of keloid tissue (n = 6). Results: TIMP-2 was downregulated in cultured KFs compared with PNFs in the same individuals, and the reduction in TIMP-2 was exacerbated by cyclic mechanical stretch. Administration of TIMP-2 (200 or 300 ng/mL) significantly suppressed expression of Col1A2 and Col3A1 mRNA and collagen type I protein in KFs. TIMP-2 also significantly reduced the skin dermal and collagen bundle thickness in ex vivo cultures of keloid tissue. Conclusion: These results indicated that downregulation of TIMP-2 in KFs is a crucial event in the pathogenesis of keloids, and the TIMP-2 would be a promising candidate for the treatment of keloids. PMID:26495233

Formation and bioactivity of HA nanorods on micro-arc oxidized zirconium.

PubMed

Zhang, Lan; Zhu, Shaoyu; Han, Yong; Xiao, Chengzhang; Tang, Wu

2014-10-01

A microporous and CaO partially stabilized zirconia (Ca-PSZ) coating covered with hydroxyapatite (HA) nanorods is fabricated on Zr substrate by a hybrid approach of micro-arc oxidation (MAO) and hydrothermal treatment (HT). The effect of P ions in HT solution on the density and morphology of HA was investigated; the hydrophilicity and apatite-forming ability of the Ca-PSZ coating with HA nanorods were also examined. High-density HA nanorods (with a mean diameter of 50 nm and length of 450 nm) grow on the Ca-PSZ coating after HT in a solution containing 0.002 M β-glycerophosphate disodium (β-GP). However, only a few of coarse-grained HA crystallites grow in the MAOed pores after HT in distilled water or in an ammonia aqueous solution with an initial pH value equal to the solution containing 0.002 M β-GP. P ions in the HT solution are thought to significantly promote the formation of HA nanorods. The Ca-PSZ coating covered with HA nanorods displays good hydrophilicity and excellent apatite-inducing ability, and the induced apatite prefers to nucleate on the basal-faceted surfaces of HA nanorods. Copyright © 2014 Elsevier B.V. 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.

Novel Triazole-Quinoline Derivatives as Selective Dual Binding Site Acetylcholinesterase Inhibitors.

PubMed

Mantoani, Susimaire P; Chierrito, Talita P C; Vilela, Adriana F L; Cardoso, Carmen L; Martínez, Ana; Carvalho, Ivone

2016-02-05

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide. Currently, the only strategy for palliative treatment of AD is to inhibit acetylcholinesterase (AChE) in order to increase the concentration of acetylcholine in the synaptic cleft. Evidence indicates that AChE also interacts with the β-amyloid (Aβ) protein, acting as a chaperone and increasing the number and neurotoxicity of Aβ fibrils. It is known that AChE has two binding sites: the peripheral site, responsible for the interactions with Aβ, and the catalytic site, related with acetylcholine hydrolysis. In this work, we reported the synthesis and biological evaluation of a library of new tacrine-donepezil hybrids, as a potential dual binding site AChE inhibitor, containing a triazole-quinoline system. The synthesis of hybrids was performed in four steps using the click chemistry strategy. These compounds were evaluated as hAChE and hBChE inhibitors, and some derivatives showed IC50 values in the micro-molar range and were remarkably selective towards hAChE. Kinetic assays and molecular modeling studies confirm that these compounds block both catalytic and peripheral AChE sites. These results are quite interesting since the triazole-quinoline system is a new structural scaffold for AChE inhibitors. Furthermore, the synthetic approach is very efficient for the preparation of target compounds, allowing a further fruitful new chemical library optimization.

ATP synthesis in Halobacterium saccharovorum: evidence that synthesis may be catalysed by an F0F1-ATP synthase

NASA Technical Reports Server (NTRS)

Hochstein, L. I.

1992-01-01

Halobacterium saccharovorum synthesized ATP in response to a pH shift from 8 to 6.2. Synthesis was inhibited by carbonyl cyanide m-chloro-phenylhydrazone, dicyclohexylcarbodiimide, and azide. Nitrate, an inhibitor of the membrane-bound ATPase previously isolated from this organism, did not inhibit ATP synthesis. N-Ethymaleimide, which also inhibited this ATPase, stimulated the production of ATP. These observations suggested that H. saccharovorum synthesized and hydrolysed ATP using different enzymes and that the vacuolar-like ATPase activity previously described in H. saccharovorum was an ATPase whose function is yet to be identified.

Synthesis and Biological Evaluation of Analogues of AKT (Protein Kinase B) Inhibitor-IV

PubMed Central

Sun, Qi; Wu, Runzhi; Cai, Sutang; Lin, Yuan; Sellers, Llewlyn; Sakamoto, Kaori; He, Biao; Peterson, Blake R.

2011-01-01

Inhibitors of the PI3-kinase/AKT (protein kinase B) pathway are under investigation as anticancer and antiviral agents. The benzimidazole derivative AKT inhibitor-IV (ChemBridge 5233705) affects this pathway and exhibits potent anticancer and antiviral activity. To probe its biological activity, we synthesized AKT inhibitor-IV and 21 analogues using a novel six-step route based on ZrCl4-catalyzed cyclization of 1,2-arylenediamines with α,β-unsaturated aldehydes. We examined effects on viability of HeLa carcinoma cells, viability of normal human cells (NHBE), replication of recombinant parainfluenza virus 5 (PIV5) in HeLa cells, and replication of the intracellular bacterium Mycobacterium fortuitum in HeLa cells. Replacement of the benzimidazole N-ethyl substitutent of AKT inhibitor-IV with N-hexyl and N-dodecyl groups enhanced antiviral activity and cytotoxicity against the cancer cell line, but these compounds showed substantially lower toxicity (from 6-fold to >20-fold) against NHBE cells, and no effect on M. fortuitum, suggesting inhibition of one or more host protein(s) required for proliferation of cancer cells and PIV5. The key structural elements identified here may facilitate identification of targets of this highly biologically active scaffold. PMID:21319800

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.

The phosphatase inhibitor menadione (vitamin K3) protects cells from EGFR inhibition by erlotinib and cetuximab.

PubMed

Perez-Soler, Roman; Zou, Yiyu; Li, Tianhong; Ling, Yi He

2011-11-01

Skin toxicity is the main side effect of epidermal growth factor receptor (EGFR) inhibitors, often leading to dose reduction or discontinuation. We hypothesized that phosphatase inhibition in the skin keratinocytes may prevent receptor dephosphorylation caused by EGFR inhibitors and be used as a new potential strategy for the prevention or treatment of this side effect. Menadione (Vitamin K3) was used as the prototype compound to test our hypothesis. HaCat human skin keratinocyte cells and A431 human squamous carcinoma cells were used. EGFR inhibition was measured by Western blotting and immunofluorescence. Phosphatase inhibition and reactive oxygen species (ROS) generation were measured by standard ELISA and fluorescence assays. Menadione caused significant and reversible EGFR activation in a dose-dependent manner starting at nontoxic concentrations. EGFR activation by menadione was associated with reversible protein tyrosine phosphatase inhibition, which seemed to be mediated by ROS generation as exposure to antioxidants prevented both menadione-induced ROS generation and phosphatase inhibition. Short-term coincubation of cells with nontoxic concentrations of menadione and the EGFR inhibitors erlotinib or cetuximab prevented EGFR dephosphorylation. Seventy-two-hour coincubation of cells with the highest nontoxic concentration of menadione and erlotinib provided for a fourfold cell growth inhibitory protection in HaCat human keratinocyte cells. Menadione at nontoxic concentrations causes EGFR activation and prevents EGFR dephosphorylation by erlotinib and cetuximab. This effect seems to be mediated by ROS generation and secondary phosphatase inhibition. Mild oxidative stress in skin keratinocytes by topical menadione may protect the skin from the toxicity secondary to EGFR inhibitors without causing cytotoxicity. ©2011 AACR

THE INTRACELLULAR SITE OF SYNTHESIS OF MITOCHONDRIAL RIBOSOMAL PROTEINS IN NEUROSPORA CRASSA

PubMed Central

Lizardi, Paul M.; Luck, David J. L.

1972-01-01

The intracellular site of synthesis of mitochondrial ribosomal proteins (MRP) in Neurospora crassa has been investigated using three complementary approaches. (a) Mitochondrial protein synthesis in vitro: Tritium-labeled proteins made by isolated mitochondria were compared to 14C-labeled marker MRP by cofractionation in a two-step procedure involving isoelectric focusing and polyacrylamide gel electrophoresis. Examination of the electrophoretic profiles showed that essentially none of the peaks of in vitro product corresponded exactly to any of the MRP marker peaks. (b) Sensitivity of in vivo MRP synthesis to chloramphenicol: Cells were labeled with leucine-3H in the presence of chloramphenicol, mitochondrial ribosomal subunits were subsequently isolated, and their proteins fractionated by isoelectric focusing followed by gel electrophoresis. The labeling of every single MRP was found to be insensitive to chloramphenicol, a selective inhibitor of mitochondrial protein synthesis. (c) Sensitivity of in vivo MRP synthesis to anisomycin: We have found this antibiotic to be a good selective inhibitor of cytoplasmic protein synthesis in Neurospora. In the presence of anisomycin the labeling of virtually all MRP is inhibited to the same extent as the labeling of cytoplasmic ribosomal proteins. On the basis of these three types of studies we conclude that most if not all 53 structural proteins of mitochondrial ribosomal subunits in Neurospora are synthesized by cytoplasmic ribosomes. PMID:4261038

Design and synthesis of (aza)indolyl maleimide-based covalent inhibitors of glycogen synthase kinase 3β.

PubMed

Yang, Zhimin; Liu, Hui; Pan, Botao; He, Fengli; Pan, Zhengying

2018-05-21

As an important kinase in multiple signal transduction pathways, GSK-3β has been an attractive target for chemical probe discovery and drug development. Compared to numerous reversible inhibitors that have been developed, covalent inhibitors of GSK-3β are noticeably lacking. Here, we report the discovery of a series of covalent GSK-3β inhibitors by optimizing both non-covalent interactions and reactive groups. Among these covalent inhibitors, compound 38b with a mild α-fluoromethyl amide reactive group emerges as a selective and covalent inhibitor against GSK-3β, effectively inhibits the phosphorylation of glycogen synthase and tau protein, and increases β-catenin's levels in living cells. In addition, compound 38b is highly permeable and not a substrate of P-glycoprotein.

Ha-ras(val12) induces HSP70b transcription via the HSE/HSF1 system, but HSP70b expression is suppressed in Ha-ras(val12)-transformed cells.

PubMed

Stanhill, A; Levin, V; Hendel, A; Shachar, I; Kazanov, D; Arber, N; Kaminski, N; Engelberg, D

2006-03-09

Heat shock proteins (Hsps) are overexpressed in many tumors, but are downregulated in some tumors. To check for a direct effect of Ha-Ras(val12) on HSP70 transcription, we transiently expressed the oncoprotein in Rat1 fibroblasts and monitored its effect on HSP70b promoter-driven reporter gene. We show that expression of Ha-Ras(val12) induced this promoter. Promoter analysis via systematic deletions and point mutations revealed that Ha-Ras(val12) induces HSP70b transcription via heat shock elements (HSEs). Also, Ha-Ras(val12) induction of HSE-mediated transcription was dramatically reduced in HSF1-/- cells. Yet, residual effect of Ha-Ras(val12) that was still measured in HSF1-/- cells suggests that some of the Ha-Ras(val12) effect is Hsf1-independent. When HSF1-/- cells, stably expressing Ha-Ras(val12), were grown on soft agar only small colonies were formed suggesting a role for heat shock factor 1 (Hsf1) in Ha-Ras(val12)-mediated transformation. Although Ha-ras(Val12) seems to be an inducer of HSP70's expression, we found that in Ha-ras(Val12-)transformed fibroblasts expression of this gene is suppressed. This suppression is correlated with higher sensitivity of Ha-ras(val12)-transformed cells to heat shock. We suggest that Ha-ras(Val12) is involved in Hsf1 activation, thereby inducing the cellular protective response. Cells that repress this response are perhaps those that acquire the capability to further proliferate and become transformed clones.

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.

The synthesis of super-small nano hydroxyapatite and its high adsorptions to mixed heavy metallic ions.

PubMed