Microcalorimetric investigation of the effect of b

Authors: Dan Yan XiaoHe Xiao Cheng Jin XiaoPing Dong

Publish Date: 2008/06/22

Volume: 51, Issue: 7, Pages: 640-645

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Abstract

The inhibitory effects of three berberine alkaloids BAs from rhizome of Coptis chinensis Franch a traditional Chinese medicinal TCM herb on Staphylococcus aureus growth were investigated by microcalorimetry The powertime curves of S aureus with and without BAs were acquired meanwhile the extent and duration of inhibitory effects on the metabolism were evaluated by studying the growth rate constant k half inhibitory ratio IC50 maximum heatoutput power P max peak time of maximum heatoutput power t p and total heat production Q t The value of k of S aureus in the presence of the three BAs decreased with the increasing concentrations of BAs Moreover P max was reduced and the value of t p increased with increasing concentrations of the three drugs The inhibitory activity varied with different drugs The values of IC50 of the three BAs are respectively 1014 μg/mL for berberine 2410 μg/mL for palmatine and 7923 μg/mL for jateorrhizine The sequence of antimicrobial activity of the three BAs is berberine palmatine jateorrhizine It is suggested that the functional group methylenedioxy or methoxyl at C2 on the phenyl ring could possibly improve antimicrobial activity more strongly than hydroxyl at C2 on the phenyl ring

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