Semisynthetic modifications of antitubercular lanostane triterpenoids from Ganoderma

Antitubercular lanostane triterpenoids isolated from mycelial cultures of the basidiomycete Ganoderma australe were structurally modified by semisynthesis. One of the synthetic compounds, named GA003 ( 9 ), showed more potent activity against Mycobacterium tuberculosis H37Ra than the lead natural lanostane ( 1 ). GA003 was also significantly active against the virulent strain (H37Rv) as well as extensively drug-resistant tuberculosis strains.