2,7,12,17-Porphinetetrapropionic acid, 3,8,13,18-tetramethyl-, tetramethyl ester 21H,23H-Porphine-2,7,12,17-tetrapropanoic acid, 3,8,13,18-tetramethyl-, tetramethyl ester 25767-20-8 Coproporphyrin I tetramethyl ester NSC89196