THE KAPURIMYCINS, NEW ANTITUMOR ANTIBIOTICS PRODUCED BY STREPTOMYCES

PHYSICO-CHEMICAL PROPERTIES AND STRUCTURE DETERMINATION

Abstract

The kapurimycins A1, A2 and A3 were revealed to be new antitumor antibiotics with molecular formula of C₂₇H₂₆O₉, C₂₆H₂₄O₉ and C₂₇H₂₄O₉, respectively. The structures of the kapurimycins were determined by NMR spectroscopic analysis. The kapurimycins are new class of polycyclic microbial metabolites having the tetrahydroanthra-γ-pyrone skeleton and the β, γ-unsaturated δ-keto carboxylic acid structure. The individual components of the kapurimycins differ from one another in the side chain at the pyrone ring of the molecule.