Phenochalasins, inhibitors of lipid droplet formation in mouse macrophages, produced by Phomopsis sp FT-0211

Phomopsis sp. FT-0211, a soil isolate, was found to produce inhibitors of l ipid droplet formation in mouse peritoneal macrophages. Structurally relate d new compounds designated phenochalasins A and B were isolated from the fe rmentation broth of the producing strain by solvent extraction, ODS column chromatography and preparative HPLC. Phenochalasin A caused a dose-dependen t reduction in the number and size of lipid droplets in macrophages without any cytotoxic effect at least up to 20 mu M. On the other hand, phenochala sin B showed inhibition of lipid droplet formation with a severe cytotoxic effect on macrophages.