Biochemically active substances from microorganisms. V. Pyrrothines, potent platelet aggregation inhibitors of microbial origin.

Abstract

Pyrrothins, known as broad-spectrum antibiotics, showed potent membrane stabilization and platelet antiaggregant activities. Thiolutin, the most potent among them, is 3 times as active as indomethacin in HH [rat erythrocyte heat hemolysis], APA [primary platelet aggregation by ADP] and CPA [secondary platelet aggregation by soluble collagen], but has no activity in the PD system. Pyrrothins exhibited strong inhibitory activity on 5-HT [serotonin] release from bovine platelets, which may be responsible in part for their platelet antiaggregant activity.