Microbiological Hydroxylation at Eight Individual Carbon Atoms of Marcfortine A

Hydroxylation of the indole alkaloid marcfortine A (1) at carbon atoms 5, 10, 12, 14, 15, 16, and 27 was realized by various soil-derived microorganisms. Fission at the C-12-N bond was also observed. The structural elucidation of the products (2-12) was accomplished by spectroscopic and semisynthetic means.