PIPERASTATIN-B - A NEW SELECTIVE SERINE CARBOXYPEPTIDASE INHIBITOR FROM STREPTOMYCES-LAVENDOFOLIAE MJ908-WF13

Piperastatin B, a new inhibitor of serine carboxypeptidase was purifie d from a culture broth of Streptomyces lavendofoliae MJ908-WF13 as a m inor component by monitoring its inhibitory activity against carboxype ptidase Y (CP-Y). Its structure was determined to be N-formyl-Val-Thr- Leu-Val-Pip-Leu-Pip (pip: piperazic acid, hexahydropyridadine-3-carbox ylic acid). Piperastatin B is a highly specific competitive inhibitor of CP-Y (K-i = 55 nM) with little effect on related enzymes and resemb les the major component, piperastatin A, in these respects.