L-Urobilinogen

(2R,3R,4S,16S,17R,18R)-2,17-Diethyl-1,2,3,4,5,10,15,16,17,18,19,22,23,24-tetradecahydro-3,7,13,18-tetramethyl-1,19-dioxo-21H-biline-8,12-dipropanoic acid

3-[2-[[3-(2-carboxyethyl)-5-[(3-ethyl-4-methyl-5-oxo-pyrrolidin-2-yl)methyl]-4-methyl-1H-pyrrol-2-yl]methyl]-5-[(4-ethyl-3-methyl-5-oxo-pyrrolidin-2-yl)methyl]-4-methyl-1H-pyrrol-3-yl]propanoic acid