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Highest Potency (highest + potency)
Selected AbstractsSynthesis of N -Substituted (3S,4S)- and (3R,4R)-Pyrrolidine-3,4-diols: Search for New Glycosidase InhibitorsHELVETICA CHIMICA ACTA, Issue 12 2004Robert N -Substituted (3S,4S)- and (3R,4R)-pyrrolidine-3,4-diols 9 and 10, respectively, were derived from (+)- L - and (,)- D -tartaric acid, respectively. Compounds 9k, 9l, and 9m with the N -substituents, BnNH(CH2)2, 4-PhC6H4CH2NH(CH2)2 and 4-ClC6H4CH2NH(CH2)2, respectively, showed modest inhibitory activities toward , - D -amyloglucosidases from Aspergillus niger and from Rhizopus mold (Table,1). Unexpectedly, several (3R,4R)-pyrrolidine-3,4-diols 10 showed inhibitory activities toward , - D -mannosidases from almonds and from jack bean (Table,3). N -Substitution by the NH2(CH2)2 group, i.e., 10g, led to the highest potency. [source] Antimicrobial activity of essential oils and structurally related synthetic food additives towards Clostridium perfringensJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2009W. Si Abstract Aims:, To assess the potential of essential oils and structurally related synthetic food additives in inhibiting the growth of Clostridium perfringens for the control of necrotic enteritis in chickens. Methods and Results:, The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Thirty-three of 66 oils/compounds exhibited ,80% inhibition. Seven with the highest potency were further studied. The oils/compounds had MIC95 values between 167 and 425 ,g ml,1. Most of them were tolerant to low pH (2·0) and exhibited minor or no inhibition of Lactobacillus isolates from the chicken intestine. When mixed with chicken ileal digesta, the oils/compounds retained their efficacy against C. perfringens, but had little effect on the total number of lactobacilli and anaerobic bacteria in the digesta. Conclusions:, Some essential oils/compounds demonstrated good potential in controlling C. perfringens. Significance and Impact of the Study:, This study has identified candidates of essential oils/compounds for in vivo studies for the control of necrotic enteritis in chickens. [source] Novel selective cytotoxicity of wild sarsaparilla rhizome extractJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2006Y. G. Huang Among six fractions, including total extract and fractions of hexane, ethyl acetate, butanol, water and boiling water extracted and separated from wild sarsaparilla rhizome, the hexane fraction (HRW) was the most effective in eliminating four different human cancer cell lines with cellular viability less than 6.8%. HRW exhibited the highest potency against human leukaemia cells with an IC50 (concentration that inhibited the growth rate of cells by 50%) of 3.3 ± 0.3 ,g mL,1, which was 17.6-fold smaller than that against normal human umbilical vein endothelial cells (IC50, 58.0 ± 1.5 ,g mL,1). For its rich natural resources, simple extraction procedure and high yield (3.2%), HRW has the potential to be developed as a selective anti-cancer nutraceutical or pharmaceutical natural health product with low side effects and high economical return. [source] The pharmacological potential of Sorbus commixta cortex on blood alcohol concentration and hepatic lipid peroxidation in acute alcohol-treated ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 5 2006Syng-Ook Lee The effect of Sorbus commixta cortex, a traditional herbal medicine used for the treatment of bronchitis, gastritis and dropsy, on blood alcohol concentration (BAC) and hepatic lipid peroxidation was examined in acute alcohol-treated rats. A 30-min pretreatment with a methanol extract of S. commixta cortex (SC) at concentrations higher than 200 mg kg,1 resulted in a significant decrease in BAC and the ethyl acetate fraction (SE) of the extract showed the highest potency, with a maximum of a 46% decrease at 150 mg kg,1 2h after alcohol administration (3.0 g kg,1) compared with the control group (P < 0.005). The rapid reduction in BAC did not appear to be due to the protection or activation of hepatic alcohol dehydrogenase (ADH) activity by SE. Hepatic malondialdehyde (MDA) levels were significantly increased by acute alcohol administration within 6h, although pretreatment with the SE caused a significant decrease in MDA levels compared with alcohol treatment alone. Hepatic glutathione (GSH) levels and superoxide dismutase (SOD) activity remained unchanged by alcohol, SE alone or by the combined treatment of alcohol and SE. However, catalase activity was significantly reduced by acute alcohol administration and pretreatment with the SE led to significant protection of its activity. These results suggest that pretreatment with SE reduces hepatic lipid peroxidation by decreasing the bioavailability of alcohol and its oxidative metabolites, such as H2O2, at least partly, through the protection of hepatic catalase in acute alcohol-treated rats. [source] Region-specific effects of N,N,-dodecane-1,12-diyl-bis-3-picolinium dibromide on nicotine-induced increase in extracellular dopamine in vivoBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2008S Rahman Background and purpose: Systemic administration of N,N,-dodecane-1,12-diyl-bis-3-picolinium dibromide (bPiDDB), an antagonist of nicotinic acetylcholine receptors (nAChRs) attenuated the nicotine-induced increase in dopamine levels in nucleus accumbens (NAcc). Experimental approach: Using in vivo microdialysis, we investigated the effects of local perfusion of the novel nAChR antagonist bPiDDB into the NAcc or ventral tegmental area (VTA) on increased extracellular dopamine in NAcc, induced by systemic nicotine. We also examined the concentration-dependent effects of bPiDDB on the acetylcholine (ACh)-evoked response of specific recombinant neuronal nAChR subtypes expressed in Xenopus oocytes, using electrophysiological methods. Key results: Nicotine (0.4 mg kg,1, s.c.) increased extracellular dopamine in NAcc, which was attenuated by intra-VTA perfusion of mecamylamine (100 ,M). Intra-VTA perfusion of bPiDDB (1 and 10 ,M) reduced nicotine-induced increases in extracellular dopamine in NAcc. In contrast, intra-NAcc perfusion of bPiDDB (1 or 10 ,M) failed to alter the nicotine-induced increase in dopamine in NAcc. Intra-VTA perfusion of bPiDDB alone did not alter basal dopamine levels, compared to control, nor the increased dopamine in NAcc following amphetamine (0.5 mg kg,1, s.c.). Using Xenopus oocytes, bPiDDB (0.01,100 ,M) inhibited the response to ACh on specific combinations of rat neuronal nAChR subunits, with highest potency at ,3,4,3 and lowest potency at ,6/3,2,3. Conclusions and implications: bPiDDB-Sensitive nAChRs involved in regulating nicotine-induced dopamine release are located in the VTA, rather than in the NAcc. As bPiDDB has properties different from the prototypical nAChR antagonist mecamylamine, further development may lead to novel nAChR antagonists for the treatment of tobacco dependence. British Journal of Pharmacology (2008) 153, 792,804; doi:10.1038/sj.bjp.0707612; published online 3 December 2007 [source] | ||||||||||