We found a new anthracycline metabolite in the culture broth of daunorubicin or baumycin (4'-substituted daunorubicin)-producing Streptomyces strains. The metabolite accumulated much more in the culture fluid rather than in the mycelial cake in contrast to a cellular accumulation of most anthracycline products. Since it contained a carboxyl group and was slightly soluble in organic solvents such as CHCl3 and EtOAc, it was not extracted by solvent from the culture broth. We could find it by the use of adsorption resin on the culture broth. This paper deals with the isolation and purification of this anthracycline metabolite, designated as D788-1 (I), from the culture broth of a blocked mutant of Streptomyces sp. D788, which was newly isolated from soil, and its chemical characterization. During this work, we also found that a novel type of anthracycline antibiotic akrobomycin, isolated from the culture broth of a carminomycin producer, could be derived from I by chemical alteration.