Synonyms: 21-Phorbinecarboxylicacid,3-(2-carboxyethenyl)-3,4-didehydro-9-ethenyl-14-ethyl-4,8,13,18-tetramethyl-20-oxo-,21-methyl ester, (E)-; 3-Phorbineacrylic acid,21-carboxy-3,4-didehydro-14-ethyl-4,8,13,18-tetramethyl-20-oxo-9-vinyl-,21-methyl ester (8CI); Pheophytin c1; Pheoporphyrin c1