Neodolastane diterpenoids from cultures of basidiomycete hydropus cf. trichoderma.

A highly conjugated 17-nor-neodolastane diterpenoid possessing a nitrile group, hydropusin A (1), and a neodolastane, hydropusin B (2a/2 b/2c), were isolated from cultures of the basidiomycete Hydropus cf. Trichoderma TBRC-BCC 43790. Hydropusin B was isolated as a mixture of three forms of interconvertible isomerization, which was supported by a deuteration experiment. Hydropusin A exhibited weak cytotoxicity to NCI-H187 and Vero cell-lines (IC50 60.6 and 64.5 μM, respectively), whereas hydropusin B showed antitubercular activity against Mycobacterium tuberculosis H37Ra (MIC 12.5 μg/mL).