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 m m for Streptococcus mitis to 0.35 m m 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 m m . The O‐benzyl cubebin derivative showed fungistatic and fungicidal effects against C. albicans at 0.28 m m and 0.35 m m , 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.