Evaluation of Piper cubeba extract, (-)-cubebin and its semi-synthetic derivatives against oral pathogens

Abstract

The activities of the crude ethanol extract from Piper cubeba seeds, (-)-cubebin and its semi-synthetic derivatives were evaluated against oral pathogens. The crude ethanol extract was more active against Streptococcus salivarius (MIC value of 80 μg/mL). (-)-Cubebin displayed MIC values ranging from 0.20 mM for Streptococcus mitis to 0.35 mM for Enterococcus faecalis. The natural product (-)-cubebin and its semi-synthetic derivative (-)-hinokinin displayed bacteriostatic activity at all evaluated concentrations, as well as fungicidal activity against Candida albicans at 0.28 mM. The O-benzyl cubebin derivative showed fungistatic and fungicidal effects against C. albicans at 0.28 mM and 0.35 mM, respectively. Also, the other dibenzylbutyrolactone derivatives [(-)-6,6′-dinitrohinokinin and (-)-O-(N,N-dimethylaminoethyl)-cubebin] displayed bacteriostatic and fungistatic effects at the evaluated concentrations. Moreover, the semi-synthetic derivative (-)-6,6′- dinitrohinokinin was the most active compound against all the evaluated microorganisms. Therefore, it may be suggested that the presence of the carbonyl group at C-9 plus the introduction of polar groups in the aromatic rings improve the antimicrobial activity of dibenzylbutyrolactone compounds. Copyright © 2007 John Wiley & Sons, Ltd.