Gyrinops walla Gaertn and an associated endophyte Fusarium dlaminii: A new sources of α and β amyrins

Abstract

Amyrins and their derivatives are pentacyclic triterpenes with well-known pharmacological properties including antimicrobial activities. The crude ethyl acetate extract (EA) of an endophytic fungus we isolated from the bark of Gyrinops walla Gaertn. showed strong, broad-spectrum antimicrobial activity against a number of human pathogens; both Gram-positive and Gram-negative bacteria including a clinical isolate of methicillin-resistant Staphylococcus aureus and Candida glabrata in Kirby-Bauer disc diffusion test. The active extract analysed by Gas Chromatography-Mass Spectrometry evident the presence of α and β Amyrin. The same two compounds were also detected in the EA extract of the inner stem bark. The sequence analysis of the DNA of the ITS regions and NCBI BLASTn search confirmed the fungus as Fusarium dlaminii (GenBank accession no. MW633321). This is the first report of fungal-derived α amyrin while G. walla is reported for the first time as a new source of both the α and β amyrins.