Clonostachin, a Novel Peptaibol That Inhibits Platelet Aggregation.

A novel peptaibol, designated clonostachin, was isolated from cultures of Clonostachys sp.F5898 by HP-20 and silica gel column chromatographies and reverse-phase HPLC.The structure ofclonostachin was determined by Edmanand chemical degradations, positive ion FAB-MS,EI-MS, and NMR analyses.Clonostachin was a linear tetradecapeptide with an TV-terminal acetyl group and a C-terminal sugar alcohol.Clonostachin inhibited ADP-induced aggregation of human platelets by 80% at 150/jm.'During the course of screening for blood coagulation inhibitors of microbial origin, we have found a novel peptaibol, clonostachin, as an active compound.In this paper, we describe the isolation, structure elucidation and biological activity of clonostachin. Materials and Methods MaterialsHumanvenous blood was drawn from healthy volunteers in 13mM sodium citrate.L-Isovaline (Iva) was