Chemical characterization of the medicinal mushroom Phellinus linteus (Berkeley & Curtis) Teng and contribution of different fractions to its bioactivity

Mushrooms are widely appreciated for their organoleptic qualities, being also recognized as good sources of bioactive compounds that provide antioxidant, antimicrobial and cytotoxic activities. Polysaccharides (including glucans) are often pointed out as the most bioactive compounds isolated from mushrooms, but other molecules such as triterpenoids, might also be highlighted for their bioactivity. In scientific research, when isolated compounds are used, potential synergistic effects might be lost. Accordingly, the bioactivity of Phellinus linteus was evaluated in selected fractions (polysaccharides, glucans and triterpenoids), as well as in the methanolic and ethanolic extracts. The best antioxidant and antibacterial activities were obtained with methanolic extract, while glucan and triterpenoid fractions gave the strongest antifungal activity. In contrast, ethanolic extract gave the best results in cytotoxic activity, indicating that the bioactive compounds present might act synergistically. The differentiated activity of P. linteus fractions and extracts could be useful to find antimicrobial, antioxidant and cytotoxic agents as alternatives to synthetic chemicals with application in agriculture, food industry or pharmacy.