Sacchathridine A, a prostaglandin release inhibitor from Saccharothrix sp.

Sacchathridine A (1) was isolated from the fermentation broth of strain Saccharothrix sp. MI559-46F5. The structure was determined as a new naphthoquinone derivative with an acetylhydrazino moiety by a combination of NMR, MS spectral analyses, and chemical degradation. Compound 1 showed inhibitory activity of prostaglandin E-2 release in a concentration-dependent manner from human synovial sarcoma cells, SW982, with an IC50 value of 1.0 mu M, but had no effect on cell growth up to 30 mu M.