Second metabolite content and antioxidative, α-amylase inhibitory activity of Phellinus gilvus fruiting body extracts

Fractions yielded  from Phellinus gilvus fruiting bodies by liquid-liquid partition of methanol extract contained various bioactive compounds such as phenolics, flavonoids and terpenes. Butanol, water and ethyl acetate fractions had high content of total phenolics, 158.12 – 247.31 mg of gallic acid equivalents (GAE)/g and low content of flavonoids, 21.74 - 36.05 mg of quercetin equivalents (QE)/g, respectively. These values highly correlated with their antioxidant activity including 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging potential with IC50 values of 84.5 -108.44 μg/mL and reducing power. These fractions showed moderate α-amylase inhibitory activity with IC50 values of 4.77, 10.69 and 3.9 mg/mL respectively. The P. gilvus fractions exhibited very slight inhibitory activity on the growth of Gram-positive and Gram-negative bacterial strains at the concentration of 20 mg/mL. The results suggest the utility of butanol, water, and ethyl acetate fractions from fruiting bodies of P. gilvus collected in Vietnam for further characterization in order to apply for diabetes or anti-aging prevention.