Isolation and characterization of a novel platelet aggregation inhibitory peptide from the medicinal mushroom, Inonotus obliquus.

This study describes the extraction and characterization of a platelet aggregation inhibitory peptide from Inonotus obliquus. Ethanol extract from I. obliquus ASI 74006 mycelia showed the highest platelet aggregation inhibitory activity (81.2%). The maximum platelet aggregation inhibitory activity was found when the mycelia of I. obliquus ASI 74006 was extracted with ethanol at 80 degrees C for 12 h. The platelet aggregation inhibitor was purified by systematic solvent fractionation, ultrafiltration, Sephadex G-10 column chromatography, and reverse-phase HPLC. The purified platelet aggregation inhibitor is a novel tripeptide with a molecular mass of 365 Da, having a sequence of Trp-Gly-Cys. The purified platelet aggregation inhibitor also showed high platelet aggregation inhibitory activity in Institute of Cancer Research (ICR) mice.