Two antimicrobial compounds drimane sesquiterpene polygodial and 11-hydroxydrim-8-en-7-one from the stem bark of Drimys arfakensis Gibbs. (Winteraceae)

Abstract

Antimicrobial-guided fractionation and isolation of the bioactive compounds from the stem bark of Drimys arfakensis Gibbs. were carried out. Two antimicrobial compounds were isolated. The sructures of the compounds were elucidated by spectroscopic methods such as 1H NMR, 13C NMR, 2-D NMR, ESI-MS and EI-MS. Based on the spectroscopic data, the two antimicrobial compounds were polygodial, 1 and and       11-Hydroxydrim-8-en-7-one, 2. . Compound 1 exhibited very strong activity against methicillin-resistant Staphylococcus aureus (MRSA) (B-1823), and yeast-like fungi Candida albicans (B-2219) with both having MIC values of  7.8 µg.mL-1.  It also showed strong activity against gram negative bacteria Escherichia coli (B-1634 ) with MIC value of 31.2 µg.mL-1 . While compound 2 only possesses strong activity against S. aureus (MRSA), no activity against C. albicans and E. coli was observed. This is the first report on the antimicrobial activity of compound 2 and on the isolation of these two compounds from D. arfakensis Gibbs.