Triterpenes from Elaeodendron schweinfurthianum and their Antimicrobial Activities against Crop Pathogens

Abstract

Phytochemical evaluation of Elaeodendron schweinfurthianum (Loes) extracts led to the isolation of nine compounds which were identified as 3-oxofriedelane (1), 3α-hydroxyfriedelane (2), 3-oxo-29-hydroxyfriedelane (3), 3-oxofriedelan-28-al (4), α-amyrin (5), α-amyrin acetate (6), β-sitosterol (7), stigmasterol (8) and lanosterol (9). The structures of the compounds were determined using spectroscopic and physical methods as well as by comparison with literature data. The in vitro antimicrobial activities of the extracts and isolates were investigated against fungi and bacteria which infect food crops. All the crude extract inhibited the growth of the tested pathogens with EtOAc and n-hexane extracts being the most active with 11.3 and 7.3 mm diameter zone of inhibition respectively. All the compound showed antimicrobial activity except compounds 3 which did not exhibit any visible activity at concentrations ≤ 200 µg/ml. Finding from this study confirm that plant extracts can provide alternative readily available and environmentally safe antimicrobials for managing crop infections.