A bioactive triterpenoid and vulpinic acid derivatives from the mushroom Scleroderma citrinum.

A new lanostane-type triterpenoid, (20 S,22 S,23 E)-22- O-acetyl-25-hydroxylanosta-8,23( E)-dien-3-one ( 1), isolated as a new natural product for the first time, methyl 4,4'-dimethoxyvulpinate ( 2), together with the known compound 4,4'-dimethoxyvulpinic acid ( 3) were isolated from the mushroom Scleroderma citrinum. Their structures were determined using spectroscopic and chemical methods, and an X-ray analysis was performed to confirm structure of 1. Compound 1 exhibited significant antiviral activity against Herpes simplex type 1. Compound 3 and two of its derivatives, the dibromo derivative 5 and acetate derivative 6, exhibited activity towards Mycobacterium tuberculosis. In addition, 5 and 6 also showed cytotoxicity against the NCI-H187 cell line.