Kedarcidin, a new chromoprotein antitumor antibiotic. II. Isolation, purification and physico-chemical properties.

Kedarcidin, a new chromoprotein antitumor antibiotic, was isolated from the culture broth of a novel actinomycete strain L585-6 (ATCC 53650). The antibiotic was recovered from the culture filtrate by adsorption to QAE ion exchanger and purified by successive application of gel filtration and ion exchange chromatography with Sephadex G-50 and DEAE-Sephadex, respectively. Kedarcidin is an acidic complex (pI 3.65) with an apparent molecular weight of 12,400. The complex consists of a highly unstable, solvent extractable chromophore and a water soluble peptide. The apoprotein is a single chain polypeptide of 114 residues.