Ammocidins B, C and D, New Cytotoxic 20-Membered Macrolides from Saccharothrix sp. AJ9571.

Ammocidins B, C and D were isolated from the culture broth of Saccharothrix sp. AJ9571, an ammocidin A-producing strain. Their structures were determined by a detailed spectroscopic analysis and by a comparison of their NMR data with those of ammocidin A. Ammocidins A and B showed potent anti-proliferative activities against human cancer cell lines.