Brasilicardins B–D, new tricyclic terpernoids from actinomycete Nocardia brasiliensis Original Research Article

Three new tricyclic terpenoids, brasilicardins B–D (2–4), were isolated together with brasilicardin A (1), a potent immunosuppressive compound, from the cultured broth of a pathogenic actinomycete Nocardia brasiliensis IFM0406, and the structures and stereochemistry were determined by spectroscopic data and a single crystal X-ray diffraction analysis. The immunosuppressive and cytotoxic activities of 2–4 were examined in the comparison with 1.