Identification of natural antifungal constituents from Agaricus bisporus (J.E. Lange) Imbach.
In agriculture, fungal invasions cause heavy loss and affect food security and food safety. Chemical pesticides are available to control these pathogens but these are associated with environmental and public health concerns. In recent years, there is a growing trend towards nature friendly methods of pathogen control. Use of allelochemicals from mushrooms is a promising field. In the present study, antifungal activity of an edible mushroom, Agaricus bisporus was investigated. For this purpose, different organic solvent extracts of A. bisporus, were evaluated against plant pathogenic fungal species viz. Macrophomina phaseolina, Aspergillus flavus, Fusarium oxysporum, Drechslera australiensis and Alternaria alternata. To check the antifungal activity of A. bisporus, serial dilution method was used. Six levels of treatments of each n-hexane, chloroform and ethyl acetate (0, 5, 10, 15, 20 and 25 mg/ml) were applied against all fungal species. Generally, all organic solvent extracts reduced the fungal biomass significantly with the increase in concentration but, ethyl acetate fraction exhibited better results and reduced the fungal growth in some species up to 50% in D. australiensis and 44% each in A. alternata and F. oxysporum. From Gas Chromatography Mass Spectrometry (GCMS) analysis of ethyl acetate fraction, 10 compounds were identified. Out of these 10 compounds, only one compound [1,2-Benzenedicarboxylic acid, mono (2-ethylhexyl) ester], molecular formula=C16H22O4 and molecular weight=278, showed 91.31% peak value. It was concluded that this compound being in the highest concentration in the ethyl acetate fraction of A. bisporus mushroom was responsible for its antifungal activity, recorded in the present study. The present investigation concluded that A. bisporus has bioactive compounds that can be exploited to develop ecofriendly fungicides against a number of plant pathogens.