From our screening program for novel antitumor antibiotics several anthracyclines (cytorhodins A~ W) belonging to the rhodomycin-group have been isolated from the Streptomyces species HPL Y-l 1472(DSM 2658). Very recently a new cytotoxic compound was isolated from this strain, which was found to have a new and unusual structure, and which we named cytorhodin X. Based on NMR, mass spectral analysis and chemical degradation cytorhodin X was identified as a heretofore unknown y-rhodomycinone glycoside containing a common trisaccharide chain at C-10 and an additional rhodosamine unit at C-9 (1). Compound 1 and its partial hydrolysis product 2 inhibited the growth of L1210 murine leukemia cells showing ED50 values of 0.36 //m and 0.51 /im, respectively. Here, we report the isolation procedure and structure elucidation of this new 9a-glycoside of the y-rhodomycin-group and its hydrolysis products. The biological properties of the new compounds and the remarkable high-field shift of some sugar proton signals in the 1H NMR spectrum of 1 are also briefly discussed.