The molecule is a dicarboxylic acid anion obtained by deprotonation of the carboxy groups as well as the 10'-hydroxy group of actinorhodin. It is the major microspecies at pH 7.3 (according to Marvin v 6.2.0.). It is a conjugate base of an actinorhodin.
2-[(1R,3S)-8-[(1R,3S)-3-(carboxylatomethyl)-6,9,10-trihydroxy-1-methyl-5-oxido-3,4-dihydro-1H-benzo[g]isochromen-8-yl]-1-methyl-5,6,9,10-tetraoxo-3,4-dihydro-1H-benzo[g]isochromen-3-yl]acetate