Major Antioxidant Compound of Polyporus Parvovarius Culture Filtrate

During the screening of natural antioxidants from the culture broths of fungi of mushroom origin, the culture broth of Polyporus parvovarius was found to exhibit potent antioxidant activity. An antioxidative substance, compound 1, was isolated by solvent partitioning and column chromatography, and its chemical structure determined by nuclear magnetic resonance spectroscopic methods to be 3,4-dihydroxybenzaldehyde. Compound 1 exhibited potent free radical scavenging activity with a half-maximal inhibitory concentration of 101.4 mu g/mL against the 2,2 '-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical. These results indicate that the culture filtrate of P. parvovarius has antioxidant properties, with the major antioxidant compound confirmed as a protocatechuic aldehyde; these findings provide novel insights regarding mushroom-induced antioxidant resources.