Activity in vitro and in vivo against plant pathogenic fungi of grifolin isolated from the basidiomycete Albatrellus dispansus.

In the course of screening for novel naturally occurring fungicides from mushrooms in Yunnan province, China, the ethanol extract of the fruiting bodies of Albatrellus dispansus was found to show antifungal activity against plant pathogenic fungi. The active compound was isolated from the fruiting bodies of A. dispansus by bioassay-guided fractionation of the extract and identified as grifolin by IR, 1H and 13C NMR and mass spectral analysis. Its antifungal activities were evaluated in vitro against 9 plant pathogenic fungi and in vivo against the plant disease of Erysiphe graminis. In vitro, Sclerotinina sclerotiorum and Fusarium graminearum were the most sensitive fungi to grifolin, and their mycelial growth inhibition were 86.4 and 80.9% at 304.9 microM, respectively. Spore germination of F. graminearum, Gloeosporium fructigenum and Pyricularia oryzae was almost completely inhibited by 38.1microM grifolin. In vivo, the curative effect of grifolin against E. graminis was 65.5% at 304.9 microM after 8 days.