Chemical constituents from Inonotus obliquus and their biological activities.

Seven new triterpenes, inonotusol A-G (1-7), one new diterpene, inonotusic acid (8), and 22 known compounds were isolated from Inonotus obliquus. Their structures were elucidated on the basis of spectroscopic analysis, including homonuclear and heteronuclear correlation NMR ((1)H-(1)H COSY, ROESY, HSQC, and HMBC) experiments. In in vitro assays, compounds 6 and 8-16 showed hepatoprotective effects against d-galactosamine-induced WB-F344 cell damage, with inhibitory effects from 34.4% to 81.2%. Compounds 7, 17, and 18 exhibited selective cytotoxicities against KB, Bel-7402, or A-549 cell lines. Compounds 16 and 17 showed inhibitory effects against protein tyrosine kinases, with IC50 values of 24.6 and 7.7 µM, respectively.

Aqueous extract from a Chaga medicinal mushroom, Inonotus obliquus (higher Basidiomycetes), prevents herpes simplex virus entry through inhibition of viral-induced membrane fusion.

Chaga medicinal mushroom, Inonotus obliquus, a popular prescription in traditional medicine in Europe and Asia, was used to reduce inflammation in the nasopharynx and to facilitate breathing. The aqueous extract from I. obliquus (AEIO) exhibited marked decrease in herpes simplex virus (HSV) infection (the 50% inhibitory concentration was 3.82 µg/mL in the plaque reduction assay and 12.29 µg/mL in the HSV-1/blue assay) as well as safety in Vero cells (the 50% cellular cytotoxicity was > 1 mg/mL, and selection index was > 80). Using a time course assay, effective stage analysis, and fusion inhibition assay, the mechanism of anti-HSV activity was found against the early stage of viral infection through inhibition of viral-induced membrane fusion. Therefore, AEIO could effectively prevent HSV-1 entry by acting on viral glycoproteins, leading to the prevention of membrane fusion, which is different from nucleoside analog antiherpetics.