Studies on neplanocin A, new antitumor antibiotic. I. Producing organism, isolation and characterization

Neplanocin A. C11H13N5O3, is a novel carbocyclic analog of adenosine with cyclopentene. It was isolated from the culture filtrate of Ampullariella regularis A11079 by means of ion-exchange, carbon, silica gel adsorption, or partition chromatography. Neplanocin A forms crystals, and is stable at acidic or alkaline pH. Neplanocin A has cytotoxicity against L5178Y cells in culture and showed a remarkable effect on the life prolongation of mice infected with L1210 leukemia.