METABOLIC PRODUCTS OF MICROORGANISMS. 234 URDAMYCINS, NEW ANGUCYCLINE ANTIBIOTICS FROM STREPTOMYCES FRADIAE

I. ISOLATION, CHARACTERIZATION AND BIOLOGICAL PROPERTIES

Abstract

The colored urdamycins A to F, six new angucycline antibiotics produced by Streptomyces fradiae strain Tü 2717, were detected by chemical screening. They are biologically active against Gram-positive bacteria and stem cells of murine L1210 leukemia. The urdamycins are glycosides and differ in their aglycones, which can be liberated by acidic hydrolysis besides the sugars D-olivose and L-rhodinose. The structure of the main compound, urdamycin A (3b), follows from the spectroscopic and chemical data in connection with an X-ray analysis. The aglycone urdamycinone A (3a) is identical with aquayamycin. The structures of urdamycin B (4b), E (3c), F and partial structures of urdamycin C and D, will be presented in a subsequent paper. The new term "angucycline/angucyclinone" is used for an increasing group of related antibiotics.