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Potent Compounds (potent + compound)
Selected AbstractsAnticonvulsant profile and teratogenicity of 3,3-dimethylbutanoylurea: A potential for a second generation drug to valproic acidEPILEPSIA, Issue 7 2008Jakob Avi Shimshoni Summary Purpose: The purpose of this study was to evaluate the anticonvulsant activity and teratogenic potential of branched aliphatic acylureas represented by isovaleroylurea (IVU), pivaloylurea (PVU) and 3,3-dimethylbutanoylurea (DBU), as potential second-generation drugs to valproic acid (VPA). Methods: The anticonvulsant activity of IVU, PVU, and DBU was determined in mice and rats utilizing the maximal electroshock seizure (MES) and the pentylenetetrazole (scMet) tests. The ability of DBU to block electrical-, or chemical-induced seizures was further examined in three acute seizure models: the psychomotor 6 Hz model, the bicuculline and picrotoxin models and one model of chronic epilepsy (i.e., the hippocampal kindled rat model). The induction of neural tube defects (NTDs) by IVU, PVU, and DBU was evaluated after i.p. administration at day 8.5 of gestation to a mouse strain highly susceptible to VPA-induced teratogenicity. The pharmacokinetics of DBU was studied following i.v. administration to rats. Results: DBU emerged as the most potent compound having an MES-ED50of 186 mg/kg (mice) and 64 mg/kg (rats) and an scMet-ED50of 66 mg/kg (mice) and 26 mg/kg (rats). DBU underwent further evaluation in the hippocampal kindled rat (ED50= 35 mg/kg), the psychomotor 6 Hz mouse model (ED50= 80 mg/kg at 32 mA and ED50= 133 mg/kg at 44 mA), the bicuculline- and picrotoxin-induced seizure mouse model (ED50= 205 mg/kg and 167 mg/kg, respectively). In contrast to VPA, DBU, IVU, and PVU did not induce a significant increase in NTDs as compared to control. DBU was eliminated by metabolism with a half-life of 4.5 h. Conclusions: DBU's broad spectrum and potent anticonvulsant activity, along with its high safety margin and favorable pharmacokinetic profile, make it an attractive candidate to become a new, potent, and safe AED. [source] Emamectin, a novel insecticide for controlling field crop pests,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2002Isaac Ishaaya Abstract Emamectin is a macrocyclic lactone insecticide with low toxicity to non-target organisms and the environment, and is considered an important component in pest-management programmes for controlling field crop pests. It is a powerful compound for controlling the cotton bollworm Helicoverpa armigera (Hübner). A spray concentration of 25,mg AI litre,1 in a cotton field resulted in over 90% suppression of H armigera larvae up to day 28 after treatment, while similar mortality of the Egyptian cotton leafworm Spodoptera littoralis Boisduval, under the same conditions, was maintained for 3 days only. Emamectin is a potent compound for controlling the western flower thrips Frankliniella occidentalis (Pergande) under both laboratory and field conditions and its activity on adults was over 10-fold greater than that of abamectin. Spray concentrations of 10 and 50,mg AI litre,1 in Ageratum houstonianum Mill flowers resulted in total suppression of adults up to day 11 and of larvae up to day 20 after treatment. Under standard laboratory conditions, emamectin exhibits a considerable activity on the whitefly Bemisia tabaci (Gennadius) and the leafminer Liriomyza huidobrensis (Blanchard). Further studies are required to evaluate its potential activity on the latter pests under field conditions. © 2002 Society of Chemical Industry [source] The Action of a Novel Fluoroquinolone Antibiotic Agent Antofloxacin Hydrochloride on Human-Ether- à-go-go- Related Gene Potassium ChannelBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2010Jia Guo In this study, the effects of a novel fluoroquinolone, antofloxacin hydrochloride (AX) on human- ether-à-go-go -related gene (HERG) encoding potassium channels and the biophysical mechanisms of drug action were performed with whole-cell patch-clamp technique in transiently transfected HEK293 cells. The administration of AX caused voltage- and time-dependent inhibition of HERG K+ current (IHERG/MiRP1) in a concentration-dependent manner but did not markedly modify the properties of channel kinetics, including activation, inactivation, deactivation and recovery from inactivation as well. In comparison with sparfloxacin (SPX), levofloxacin lactate (LVFX), the potency of AX to inhibit HERG tail currents was the least one, with an IC50 value of 460.37 ,M. By contrast, SPX was the most potent compound, displaying an IC50 value of 2.69 ,M whereas LVFX showed modest potency, with an IC50 value of 43.86 ,M, respectively. Taken together, our data suggest that AX only causes a minor reduction of IHERG/MiRP1 at the estimated free plasma level. [source] New Peptolides from the Cyanobacterium Nostoc insulare as Selective and Potent Inhibitors of Human Leukocyte ElastaseCHEMBIOCHEM, Issue 16 2008Christian Mehner Abstract Eight new cyanopeptolins (insulapeptolides A,H) were obtained from the cyanobacterium Nostoc insulare. Their isolation was guided by their bioactivity toward the target enzyme human leukocyte elastase, molecular biological investigations, and MALDI-TOF analysis. These peptides are selective inhibitors of human leukocyte elastase with activities in the nanomolar range. Insulapeptolide D (4) was the most potent compound with an IC50 value of 85 nM (Ki value of 36 nM). [source] Xylogranatins F,R: Antifeedants from the Chinese Mangrove, Xylocarpus granatum, A New Biogenetic Pathway to TetranortriterpenoidsCHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2008Jun Wu Dr. Abstract Thirteen limonoids with a new carbon skeleton, the xylogranatins,F,R (1,13), have been isolated from the seeds of a Chinese mangrove, Xylocarpus granatum; two recently reported compounds, xylogranatins,C and,D were also isolated. Their structures were elucidated on the basis of spectroscopic data and chemical methods. The absolute configurations of these compounds were determined by using the modified Mosher MTPA ester method and by quantum chemical circular dichroism (CD) calculations. Xylogranatins,F,Q are the first aromatic B-ring limonoids found in nature. They belong to two substructural classes, of which one (1,3) contains a pyridine ring while the other one (4,12) contains a central furan core. Xylogranatins,C and,R can be considered to be key biosynthetic intermediates, while xylogranatin,D, the only limonoid found so far with a carbon skeleton that conatains a C30C9 linkage, is apparently an artifact. The structures of these compounds suggest a new biogenetic pathway to tetranortriterpenoids. Xylogranatins,F, G and R were found to exhibit marked antifeedant activity against the third instar larvae of Mythimna separata (Walker) at a concentration of 1,mg,mL,1. The most potent compound tested was xylogranatin,G. Its AFC50 (concentration for 50,% antifeedant activity) values at the exposure times of 24 and 48,h were 0.31 and 0.30,mg,mL,1, respectively. [source] Identification, SAR Studies, and X-ray Co-crystallographic Analysis of a Novel Furanopyrimidine Aurora Kinase,A InhibitorCHEMMEDCHEM, Issue 2 2010Mohane Selvaraj Coumar Dr. Abstract Herein we reveal a simple method for the identification of novel Aurora kinase,A inhibitors through substructure searching of an in-house compound library to select compounds for testing. A hydrazone fragment conferring Aurora kinase activity and heterocyclic rings most frequently reported in kinase inhibitors were used as substructure queries to filter the in-house compound library collection prior to testing. Five new series of Aurora kinase inhibitors were identified through this strategy, with IC50 values ranging from ,300,nM to ,15,,M, by testing only 133 compounds from a database of ,125,000 compounds. Structure,activity relationship studies and X-ray co-crystallographic analysis of the most potent compound, a furanopyrimidine derivative with an IC50 value of 309,nM toward Aurora kinase,A, were carried out. The knowledge gained through these studies could help in the future design of potent Aurora kinase inhibitors. [source] 5-HT1A RECEPTOR AGONIST PROPERTIES OF ANTIPSYCHOTICS DETERMINED BY [35S]GTP,S BINDING IN RAT HIPPOCAMPAL MEMBRANESCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2007Yuji Odagaki SUMMARY 15-Hydroxytryptamine 1A (5-HT1A) receptors have attracted increasing attention as a promising target for antipsychotic therapy. Although many atypical antipsychotic drugs, including the prototype clozapine, have been reported to be partial agonists at 5-HT1A receptors, these results are often fragmental and derived mainly from experiments that used cultured cells. 2In the present study, [35S]guanosine 5,- O -(3-thiotriphosphate) ([35S]GTP,S) binding assay in rat hippocampal membranes was applied to a series of antipsychotic drugs, especially atypical antipsychotics. 3Most, but not all, of atypical antipsychotic drugs and the classical antipsychotic drug nemonapride behaved as partial agonists at 5-HT1A receptors with varied potencies and relative efficacies. The most potent compound was perospirone with a mean EC50 of 27 nmol/L, followed by aripiprazole (45 nmol/L) > ziprasidone (480 nmol/L) > nemonapride (790 nmol/L) > clozapine (3900 nmol/L) > quetiapine (26 000 nmol/L). The maximal percentage increases over the basal binding (%Emax) for these antipsychotic drugs were 30,50%, with the exception of perospirone (, 15%), whereas 5-HT stimulated the binding to a mean %Emax of 105%. 4Increasing concentrations of the selective and neutral 5-HT1A antagonist WAY100635 shifted the concentration,response curve of nemonapride-stimulated [35S]GTP,S binding to the right and in parallel. 5The relative efficacy or intrinsic activity of a compound was affected differently by the differing concentrations of guanosine diphosphate (GDP) in the assay buffer, which should be taken into consideration when determining the relative efficacies of these antipsychotics as 5-HT1A receptor agonists. 6These results provide important information concerning the relevance of 5-HT1A receptor partial agonist properties in the treatment for schizophrenic patients with most, if not all, of atypical antipsychotic drugs. [source] Thymol analogues with antioxidant and L-type calcium current inhibitory activityDRUG DEVELOPMENT RESEARCH, Issue 4 2005Ai-Yu Shen Abstract Thymol is a natural product, which has antioxidant activity. 4-Morpholinomethyl-2-isopropyl-5-methylphenol (THMO), and 4-Pyrrolidinomethyl-2-isopropyl- 5-methylphenol (THPY) were synthesized by reacting thymol with formaldehyde and, respectively, morpholine or pyrrolidine. Since there is a relationship between the antioxidative status and incidence of human disease, anti-superoxidation, free radical scavenger activity, and anti-lipid peroxidation of the thymol analogues were determined by xanthine oxidase inhibition, cytochrome C system with superoxide anion releasing with formyl-Met-Leu-Phe (fMLP)/cytochalasin (CB) or phorbol myristate acetate (PMA) activating pathway in human neutrophils. All compounds studied had antioxidant activity. Mannich bases derived from thymol were generally found to be more potent compounds than thymol. THMO demonstrated the greatest antioxidant activity with IC50 values for xanthine oxidase inhibition and anti-lipid peroxidation being 21±2.78 and 61.29±5.83 µM, respectively. Moreover, since oxidative stress by free radical regulates the activity of L-type Ca2+ channel, the whole-cell configuration of the patch-clamp technique was used to investigate the effect of THMO upon ionic currents within NG108-15 cells. THMO (10 µM) suppressed the peak amplitude of L-type Ca2+ inward current (ICa,L), indicating that the antioxidative potential of the thymol analogues might be related to calcium current inhibition. The present studies suggest that THMO-dependent antioxidant and calcium ion current inhibition activity may be useful in treating free radical-related disorders. Drug Dev Res 64:195,202, 2005. © 2005 Wiley-Liss, Inc. [source] Molecular docking studies of selected tricyclic and quinone derivatives on trypanothione reductase of Leishmania infantumJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 13 2010Santhosh Kannan Venkatesan Abstract Visceral leishmaniasis, most lethal form of Leishmaniasis, is caused by Leishmania infantum in the Old world. Current therapeutics for the disease is associated with a risk of high toxicity and development of drug resistant strains. Thiol-redox metabolism involving trypanothione and trypanothione reductase, key for survival of Leishmania, is a validated target for rational drug design. Recently published structure of trypanothione reductase (TryR) from L. infantum, in oxidized and reduced form along with Sb(III), provides vital clues on active site of the enzyme. In continuation with our attempts to identify potent inhibitors of TryR, we have modeled binding modes of selected tricyclic compounds and quinone derivatives, using AutoDock4. Here, we report a unique binding mode for quinone derivatives and 9-aminoacridine derivatives, at the FAD binding domain. A conserved hydrogen bonding pattern was observed in all these compounds with residues Thr335, Lys60, His461. With the fact that these residues aid in the orientation of FAD towards the active site forming the core of the FAD binding domain, designing selective and potent compounds that could replace FAD in vivo during the synthesis of Trypanothione reductase can be deployed as an effective strategy in designing new drugs towards Leishmaniasis. We also report the binding of Phenothiazine and 9-aminoacridine derivatives at the Z site of the protein. The biological significance and possible mode of inhibition by quinone derivatives, which binds to FAD binding domain, along with other compounds are discussed. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 [source] Structure,activity relationship study of alkynyl ether insecticide synergists and the development of MB-599 (verbutin),PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2003Béla Bertók Abstract Structure,activity relationships of aryl alkynyl synergists of the general formula of Ar,Q,R, where Q represents a bridging structure, were studied using a standardised testing system and Relative Potency values. Ethers, esters, oxime ethers, amides and amines were prepared and evaluated. The length of the R-alkynyl chain, the role of the bridge and the substitution of the aromatic ring were examined systematically. The most potent compounds possessed an aromatic ring connected via a bridge of three atoms to an alkynyl chain, forming together a linear side-chain of six atoms. Several highly potent compounds were synthesised of which one (MB-599; proposed common name verbutin) was selected for development as a selective insecticide synergist in crop protection. Its high potential at practical insecticide:synergist ratios makes possible the reduction of the total amount of insect-control chemicals applied, and its use as an additive to produce new formulations of existing insecticides makes it highly advantageous in resistance management, giving a new tool to sustain the effectiveness of a wide range of insecticides. A product containing a (1,+,1) mixture of verbutin and beta-cypermethrin was launched in Hungary in 2002. © 2003 Society of Chemical Industry [source] Synthesis, Antibacterial and Antifungal Activities of Novel 1,2,4-Triazolium DerivativesARCHIV DER PHARMAZIE, Issue 7 2009Yan Luo Abstract A series of novel 1,2,4-triazolium derivatives was synthesized starting from commercially available 1H -1,2,4-triazole, 2,4-dichlorobenzyl chloride, or 2,4-difluorobenzyl bromide. Their antibacterial and antifungal activities were evaluated against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Bacillus proteus, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans ATCC 76615, and Aspergillus fumigatus. All structures of the new compounds were confirmed by NMR, IR, and MS spectra, and elemental analyses. The antimicrobial tests showed that most of synthesized triazolium derivatives exhibit significant antibacterial and antifungal activities in vitro. 1-(2,4-Difluorobenzyl)-4-dodecyl-1H -1,2,4-triazol-4-ium bromide and 1-(2,4-Dichlorobenzyl)-4-dodecyl-1H -1,2,4- triazol-4-ium bromide were the most potent compounds against all tested strains with the MIC values ranging from 1.05 to 8.38 ,M. They exhibited much stronger activities than the standard drugs chloramphenicol and fluconazole which are in clinical use. The results also showed that the antimicrobial activities of triazolium derivatives depend upon the type of substituent, the length of the alkyl chain, and the number of triazolium rings. [source] Discovery and Potency Optimization of 2-Amino-5-arylmethyl-1,3-thiazole Derivatives as Potential Therapeutic Agents for Prostate CancerARCHIV DER PHARMAZIE, Issue 7 2009Mikhail Krasavin Abstract A new chemical series was identified via high-throughput screening as having antiproliferative activity on DU-145 human prostate carcinoma cell line (hit compound potency , 2.9 ,M). Medicinal chemistry optimization of two peripheral diversity vectors of the hit molecule, independently, led to SAR generalizations and identification of the ,best' moieties. The latter were merged in a single compound that exhibited an over 100-fold better potency than the hit compound. For the most potent compounds it was confirmed that the observed antiproliferative potency was not associated with the compounds' non-specific cytotoxicity. [source] Structure of the ligand-binding domain of rat VDR in complex with the nonsecosteroidal vitamin D3 analogue YR301ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2008Shinji Kakuda Vitamin D receptor (VDR) is a ligand-inducible hormone receptor that mediates 1,,25(OH)2D3 action, regulating calcium and phosphate metabolism, induces potent cell differentiation activity and has immunosuppressive effects. Analogues of 1,,25(OH)2D3 have been used clinically for some years. However, the risk of potential side effects limits the use of these substances. LG190178 is a novel nonsecosteroidal ligand for VDR. (2S)-3-[4-(3-{4-[(2R)-2-hydroxy-3,3-dimethylbutoxy]-3-methylphenyl}pentan-3-yl)-2-methylphenoxy] propane-1,2-diol (YR301) is the only one of the four evaluated stereoisomers of LG190178 to have strong activity. To understand the strong activity of YR301, the crystal structure of YR301 complexed with the rat VDR ligand-binding domain (VDR LBD) was solved at 2.0,Å resolution and compared with the structure of the VDR LBD,1,,25(OH)2D3 complex. YR301 and 1,,25(OH)2D3 share the same position and the diethylmethyl group occupies a similar space to the C and D rings of 1,,25(OH)2D3. YR301 has two characteristic hydroxyl groups which contribute to its potent activity. The first is 2,-OH, which forms hydrogen bonds to the NE2 atoms of both His301 and His393. The other is 2-OH, which interacts with Ser233,OG and Arg270,NH1. These two hydroxyl groups of YR301 correspond exactly to 25-OH and 1-OH, respectively, of 1,,25(OH)2D3. The terminal hydroxyl group (3-OH) of YR301 is directly hydrogen bonded to Arg270 and also interacts indirectly with Tyr232,OH and the backbone NH of Asp144 via water molecules. Additional derivatization of the terminal hydroxyl group using the positions of the water molecules might be useful for the design of more potent compounds. [source] Oligosaccharide Mimics Containing Galactose and Fucose Specifically Label Tumour Cell Surfaces and Inhibit Cell Adhesion to FibronectinCHEMBIOCHEM, Issue 2 2005Evelyn Y.-L. Abstract With the aim of establishing a versatile and easy synthesis of branched saccharides for biological applications, we used molecular-dynamics simulations to model Lewisyto two classes of di- or triantennary saccharide mimetics. One set of mimetics was based on 1,3,5-tris(hydroxymethyl)cyclohexane (TMC) as the core, the other on furan, and both were derivatised with galactose and/or fucose. The TMC-based saccharides were biotinylated, while the furan disaccharides were treated with maleimide-activated biotin in a Diels,Alder fashion to yield oxazatricyclodecanes (OTDs). These were then assayed as cell-surface labels in human colon (SW480 and CaCo-2), liver (PLC), Glia (U333,CG,343) and ovary (SKOV-3) tumour cell lines. Discrete staining patterns were observed in all cells, usually at one or two poles of the cells, particularly with the asymmetric 3-,- L -fucopyranosyloxymethyl-4-,- D -galactopyranosyloxymethyl-OTD. Normal SV40-transformed fibroblasts (SV80) showed no staining. Adhesion of the highly metastatic mouse melanoma line B16,F10 to fibronectin was inhibited by 80,% by the TMC-digalactoside and by 30,% by 3,4-bis-(,- D -galactopyranosyloxymethyl)furan. None of the saccharide mimetics inhibited the adhesion of the less metastatic B16,F1 line. Migration of B16,F10 cells through MatrigelTMwas greatly inhibited by the TMC-digalactoside and weakly inhibited by the TMC-trigalactoside. The saccharide mimetics that had shown the best structural agreements with the terminal saccharides of Lewisyin the molecular dynamics simulation were also the most biologically potent compounds; this underlines the predictive nature of molecular dynamics simulations. The use of the non-saccharide cores enabled us to adapt spacer lengths and terminal saccharides to optimise the structures to bind more avidly to cell-surface lectins. [source] Discovery of Adamantyl Ethanone Derivatives as Potent 11,-Hydroxysteroid Dehydrogenase Type,1 (11,-HSD1) InhibitorsCHEMMEDCHEM, Issue 7 2010Xiangdong Su Dr. Abstract 11,-Hydroxysteroid dehydrogenases (11,-HSDs) are key enzymes regulating the pre-receptor metabolism of glucocorticoid hormones. The modulation of 11,-HSD type,1 activity with selective inhibitors has beneficial effects on various conditions including insulin resistance, dyslipidemia and obesity. Inhibition of tissue-specific glucocorticoid action by regulating 11,-HSD1 constitutes a promising treatment for metabolic and cardiovascular diseases. A series of novel adamantyl ethanone compounds was identified as potent inhibitors of human 11,-HSD1. The most active compounds identified (52, 62, 72, 92, 103 and 104) display potent inhibition of 11,-HSD1 with IC50 values in the 50,70,nM range. Compound 72 also proved to be metabolically stable when incubated with human liver microsomes. Furthermore, compound 72 showed very weak inhibitory activity for human cytochrome P450 enzymes and is therefore a candidate for in,vivo studies. Comparison of the publicly available X-ray crystal structures of human 11,-HSD1 led to docking studies of the potent compounds, revealing how these molecules may interact with the enzyme and cofactor. [source] | |||||||||||||