Synonyms: 21H,23H-Porphine-2,7,12,18-tetrapropanoic acid, 3,8,13,17-tetramethyl-, hydrochloride (1:2);Coproporphyrin III, dihydrochloride;21H,23H-Porphine-2,7,12,18-tetrapropanoic acid, 3,8,13,17-tetramethyl-, dihydrochloride;3,8,13,17-Tetramethyl-21H,23H-porphine-2,7,12,18-tetrapropionic acid dihydrochloride