The molecule is a linear tetrapyrrole obtained by degradation of heme by an enzyme isolated from Escherichia coli O157:H7. It is a linear tetrapyrrole and a dicarboxylic acid. It is a tautomer of an anaerobilin dizwitterion.
3-[(2Z,5Z)-5-[[2,4-bis(ethenyl)-3-methyl-2H-pyrrol-5-yl]methylidene]-2-[[3-(2-carboxyethyl)-5-[(Z)-(4-ethenyl-3-methylpyrrol-2-ylidene)methyl]-4-methyl-1H-pyrrol-2-yl]methylidene]-4-methylpyrrol-3-yl]propanoic acid