Isolation of bioactive metabolites from root extracts of Polyalthia debilis

Abstract

Bioactive azafluorenone alkaloids from Polyalthia debilis were previously reported. Herein, bioactive root extracts of P. debilis (hexane and methanol) with antimalarial, antimicrobial and cytotoxic activities were further explored. Upon repeated chromatographic isolations of the extracts gave triterpenes; 3-acetylaleuritolic acid (1), suberosol (4) and stigmasterol (2) together with a mixture of stigmasterol and β-sitosterol (3) including many fractions of triterpenes mixture. Compounds 1 and 4 were isolated from the P. debilis for the first time. The sterol 3 exhibited antifungal action against Saccharomyces cerevisiae ATCC 2601 with a minimum inhibitory concentration of 64 μg/mL. Some of the isolated fractions were also shown to be antifungals. The results provide medicinal applications of the plant species. © EuroJournals Publishing, Inc. 2009.