Modification of Cellular Membrane Functions by Pendolmycin

Pendolmycin is a new indole alkaloid isolated from Nocardiopsis as an inhibitor of phosphatidyl‐inositol turnover. Structurally, pendolmycin is similar to teleocidin B and lyngbyatoxin A. Pendolmycin, teleocidin B and 12‐O‐tetradecanoylphorbol‐13‐acetate all inhibited phosphatidylinositol turnover in A431 cells. Pendolmycin inhibited binding of epidermal growth factor, activated ara‐chidonic acid release and hexose transport, and inhibited binding of phorbol‐12,13‐tlibutylate in C3H10T1/2 cells. Thus, pendolmycin was as potent as teleocidin B and phorbol ester tumor promoters in modification of cell membrane functions, while having the simplest structure among them.