Wild-growing lignicolous mushroom species as sources of novel agents with antioxidative and antibacterial potentials

Crude extracts of two edible and two medicinal lignicolous mushroom species: Meripilus giganteus, Agrocybe aegerita, Fomes fomentarius and Xylaria polymorpha, growing wild in Serbia, were analyzed for their antioxidative and antibacterial potentials. Free radical scavenging capacity (RSC) on DPPH(•) and (•)OH was evaluated both by spectrophotometer and by Electron Spin Resonance (ESR) spectroscopy against DPPH(•). The highest antioxidant and antibacterial bioactivity was obtained with F. fomentarius extracts (IC50 ≈ 10.7 µg/ml in DPPH(•) assay; 136.6 mg ascorbic acid equivalents (AAE)/g dry weight (d.w.) for ferric reducing antioxidant power FRAP). It also showed the highest total phenol (TP) (82.54 mg gallic acid equivalents (GAE)/g dry weight (d.w.)) and total flavonoid (TF) content (76.8 µg rutin equivalents (RE)/g dry weight (d.w.)). A. aegerita showed the best antioxidant activity (IC50 = 0.87 mg/ml) against DPPH(•) in ESR analysis. Total redox potential of extracts was in direct positive correlation with TP content (r(2 )= 0.98) and TF content (r(2 )= 0.58). GC/MS analysis detected major constituents of extracts, confirming the presence of the following organic and phenolic acids: fumaric, succinic, mallic, 4-hydroxy benzoic, gentisic, protocatechuic, vanillic, gallic and p-coumaric acid.