Potential antifungal constituents of Sonchus oleraceous against Macrophomina phaseolina

Abstract

This study was done to identify possible antifungal compounds in Sonchus oleraceous L. (family Asteraceae) against Macrophomina phaseolina (Tassi.) Goid., a highly destructive fungal pathogen. Initially, methanolic extracts (10 to 50 mg mL-1) of stem, leaf, inflorescence and root of this Asteraceous weed were assayed against M. phaseolina which reduced biomass of the fungal pathogen by 54-84%, 7-73%, 51-87%, and 49-82%, respectively, over control. The most effective stem extract was fractionated with four solvents of variable polarities. Laboratory trials with 3.125 to 200 mg mL-1 concentrations revealed that chloroform fraction was the most antifungal followed by n-hexane fraction resulting in 60-90% and 15-66% control in fungal biomass, respectively. GC-MS examination of chloroform fraction resulted in identification of 14 compounds. Hexadecanoic acid, methyl ester (13.26%), 11-octadecanoic acid, methyl ester (13.12%), 9, 12-octadecadienoyl chloride, (Z,Z)- (12.96%), 1-docosanol (8.62%), and 1, 2-benzenedicarboxylic acid, diisooctyl ester (8.28%) were the pre-dominant compounds in this fraction that might be the cause of M. phaseolina management.