Isolation of a non-protein component and a protein component from neocarzinostatin (NCS) and their biological activities.

An antitumor antibiotic of protein nature1), neocarzinostatin (NCS), was isolated in 1965 from culture filtrates of Streptomyces carzinostaticus var. F-41 by ISHIDA et al.2) It has been reported that NCS inhibits DNA synthesis3) and cell division4), and it causes DNA strand breakage5,6) and induces DNA repair synthe-