Neogrisemycin, a Trisulfide-Bridged Angucycline, Produced upon Expressing the Thioangucycline Biosynthetic Gene Cluster in Streptomyces albus J1074.

Neogrisemycin ( 1 ) was isolated from recombinant Streptomyces albus J1074 strain SB4061 expressing an engineered thioangucycline (TAC) biosynthetic gene cluster (BGC). The structure and absolute configuration of 1 were established by a combination of mass spectrometry, nuclear magnetic resonance, and single-crystal X-ray diffraction analyses. Like the TACs, 1 was also proposed to derive non-enzymatically from the common epoxide ( 8 ), the nascent product encoded by the tac BGC, mediated by endogenous hydrogen trisulfide.