The molecule is a dicarboxylic acid dianion obtained by deprotonation of the two carboxy groups of bilirubin; major species at pH 7.3. It has a role as a human metabolite. It is a linear tetrapyrrole anion and a dicarboxylic acid dianion. It is a conjugate base of a bilirubin IXalpha.
3-[2-[[3-(2-carboxylatoethyl)-5-[(Z)-(3-ethenyl-4-methyl-5-oxopyrrol-2-ylidene)methyl]-4-methyl-1H-pyrrol-2-yl]methyl]-5-[(Z)-(4-ethenyl-3-methyl-5-oxopyrrol-2-ylidene)methyl]-4-methyl-1H-pyrrol-3-yl]propanoate