Antioxidant activities and bioactive compound determination from caps and stipes of specialty medicinal mushrooms Calocybe indica and Pleurotus sajor-caju (higher Basidiomycetes) from India.

In this study, we evaluated total phenolics, condensed tannins, ascorbic acid, lycopene, β-carotene, total antioxidant activity, reducing power, ferric-reducing antioxidant power, and radical scavenging activity (RSA) on ABTS and DPPH as well as metal chelating activity of methanolic and aqueous extract from caps and stipes of Calocybe indica and Pleurotus sajor-caju mushrooms. Per gram of extract, the different mushroom extracts contained 18.09-27.47 mg gallic acid equivalent of phenolics, 5.06-8.89 mg catechins of tannins, and 0.15-0.21 mg ascorbic acid. Principal component analysis (PCA) revealed that methanolic extract from caps of C. indica and P. sajor-caju contained higher ascorbic acid, total antioxidant activity, β-carotene and radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) than did the stipes. The aqueous extract from cap and stipe of P. sajor-caju had higher total phenolics and RSA on 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) as well as higher metal-chelating activity and ferric-reducing antioxidant power. The antioxidant potential is higher in the caps of P. sajor-caju and C. indica than in the stipes; the cap contributes most to antioxidant activity.