Donghaesulfins A and B, Dimeric Benz[ a]anthracene Thioethers from Volcanic Island Derived Streptomyces sp.

The chemical analysis of a Streptomyces strain, from a Korean volcanic island, discovered new benz[ a]anthracene dimers linked by a thioether bond. The structures of donghaesulfins A and B (1 and 2) were elucidated by spectroscopic analysis including energy-dispersive X-ray. Their configurations were determined by ROESY NMR data, DP4 calculations, the modified Mosher's method, and ECD calculations. Donghaesulfins A (1) induced quinone reductase, whereas donghaesulfin B (2) displayed antiangiogenesis activity.