8,12-Dides(2-carboxyethyl)-8,12-bis[2-(methoxycarbonyl)ethyl]-31,32,181,182-tetrahydrobiliverdin

3,18-Diethyl-1,19,22,24-tetrahydro-2,7,13,17-tetramethyl-1,19-dioxo-21H-biline-8,12-dipropionic acid dimethyl ester