Inhibition of intercellular communication in Chinese hamster V79 cells by teleocidin

Teleocidin, a mixture of teleocidin A and teleocidin B, was found to block metabolic cooperation between the 6-thioguanine-resistant and the 6-thioguanine-sensitive cells in the Chinese hamster V79 cell system. A teleocidin B preparation containing two isomers exerted the same effect. The dose-response curves of these two compounds were, in general, similar to that of 12-O-tetradecanoyl-phorbol-13-acetate, a powerful mouse skin tumor promoter. Upon hydrolysis with 6M hydrochloric acid containing 4% thioglycolic acid, teleocidin lost most of its ability to block metabolic cooperation. This was probably caused by the conformational change resulting from the rupture of the nine-membered lactam ring of teleocidin.