Chemical composition and antimicrobial and cytotoxic activities of Antidesm abunius L

It was deemed of interest to investigate Antidesm bunius aerial parts from phytochemical and biological points of view due to limited previous studies. Isolation and identification of phenolic compounds and evaluation of the potential antimicrobial and cytotoxic effects of A. bunius aerial parts was investigated. The petroleum ether (PEE) and 80% EtOH extracts (EE), as well as, n-hexane (HF), CHCl3 (CF), EtOAc (EAF), n-BuOH (BF) and H2O soluble fractions (WF) of the latter were prepared. Phytochemical study has been performed for isolation and identification of the major polyphenols. Antimicrobial activity, using diffusion agar technique, and potential cytotoxic effect against HepG2, MCF7 and HCT cell lines were evaluated. Malic acid (I), caffeic acid (II), methyl benzoate (III), (+)-catechin (IV), (-)-epicatechin (V), epicatechin-(4β→8)-catechin (procynidin B1, VI) and epicatechin-(4β→8)-epicatechin (procyanidin B2, VII) were isolated. Compounds I-VII showed strong to moderate antimicrobial activity, with MIC values in the range of 1.95-125μg/ml except for compounds 1 and IV, which did not show any effect. All tested samples showed dose dependent cytotoxic effect against all three tested cell lines. PEE showed strong cytotoxic activity (IC50=23.7-38.2μg/ml). Furthermore, compound VI showed potent cytotoxicity against HepG2, MCF7 and HCT cell lines (IC₅₀=24.7, 16.5 and 18.0μg/ml) respectively. The strong to moderate antimicrobial activity and cytotoxic effect of the plant could be attributed to its content of phenolic acids, flavan-3-ols and/or proanthocyanidins. These findings were confirmed by results obtained for the isolated compounds.