Metabolic products of microorganisms. 225¹) elloramycin, a new anthracycline-like antibiotic from streptomyces olivaceus isolation, characterization, structure and biological properties

Elloramycin (1), a new antibiotic produced byStreptomyces olivaceus strain Tü 2353, was detected by chemical screening. The dark yellow compound, molecular formula C₃₂;H₃₆O₁₅, is weakly active against avariety of Gram-positive bacteria, especiallystrepto-mycetes and against stem cells of L-1210 leukemia. Acidic hydrolysis of the antibiotic liberated elloramycinone (3) as aglycone and 2,3,4-tri-O-methyl-L-rhamnose, which was identified as methyl glycoside 5b. The structure of elloramycin was established by comparison of the spectra (UV, ¹H NMR, ¹³C NMR)with those of the known tetracenomycin C (2),3 and the fact that 2 and 3 gave the same tetramethyl ether after permethylation. Elloramycin is an anthracycline-like antibiotic, the aglycone resembles tetracenomycin C, the sugar is connected in a phenolic α-glycosidic linkage.