In the screening for new antitumor anthracycline antibiotics, anthracycline glycosides with novel aglycones were isolated from Streptomyces sp. OBB-111 (classified as S. galilaeus), a strain isolated from a soil sample in Bayern, West Germany. The strain was cultured in a medium containing glucose, soluble starch, S-3 meat, yeast extract, K₂HPO₄, MgSO₄·7H₂O, NaCl, and CaCO₃, with shaking at 180 rpm and 27°C for 7 days. Yellow antibiotics were extracted using a chloroform-methanol (1:1) mixture and recovered in the chloroform layer. Crude extracts contained multiple components, with major ones identified as aclacinomycin A, B, and their analogues (MA144-M1, -N1, -S1, -T1). Mass fragmentation analysis revealed anthracyclines with two distinct aglycones, named auramycins and sulfurmycins. Hydrolysis of the glycosides yielded the aglycones aklavinone, auramycinone, and sulfurmycinone. Auramycinone (C₂₁H₁₈O₈) exhibited a melting point (m.p.) of 153.5°C, a specific rotation ([α]²⁰ᴰ) of -178° (c 0.1, CHCl₃), and elemental analysis consistent with its molecular formula. Sulfurmycinone (C₂₃H₂₀O₉) had a m.p. of 159°C, [α]ᴰ of +232.2° (c 0.1, CHCl₃), and matching elemental analysis. Chromatographic (HPLC, TLC), UV, IR, ¹H-NMR, and ¹³C-NMR data indicated auramycinone possesses a methyl group at C-9 (replacing the ethyl group in aklavinone), while sulfurmycinone contains an additional carbonyl group and an acetonyl side chain at C-9. The absolute configuration at C-7, C-9, and C-10—determined via ORD and CD spectra—matched that of aklavinone. Auramycinone and sulfurmycinone are unique anthracycline aglycones: auramycinone has a methyl group at C-9, sulfurmycinone an acetonyl group, and both bear a carbomethoxy group at C-10, distinguishing them from known anthracycline aglycones.