The molecule is a synthetic dipyrrin derived from rings A and D of bilirubin IXalpha in which C-9 carries a phenyldiazenyl substituent. It is a member of dipyrrins and an azo compound. It is a tautomer of a 3-[(2E)-4-methyl-5-[(Z)-(4-methyl-5-oxo-3-vinyl-1,5-dihydro-2H-pyrrol-2-ylidene)methyl]-2-(phenylhydrazono)-2H-pyrrol-3-yl]propanoic acid.
3-[5-[(Z)-(3-ethenyl-4-methyl-5-oxopyrrol-2-ylidene)methyl]-4-methyl-2-phenyldiazenyl-1H-pyrrol-3-yl]propanoic acid