The molecule is a zwitterion obtained by transfer of a proton from the carboxy to the primary amino group of 10-carboxy-13-deoxycarminomycin; major species at pH 7.3. It is a tautomer of a 10-carboxy-13-deoxycarminomycin.
(1R,2R,4S)-4-[(2R,4S,5S,6S)-4-azaniumyl-5-hydroxy-6-methyloxan-2-yl]oxy-2-ethyl-2,5,7,12-tetrahydroxy-6,11-dioxo-3,4-dihydro-1H-tetracene-1-carboxylate