The molecule is a cyclic tetrapyrrole anion that is the carbanion obtained by removal of the acidic proton from position 21 of pheophytin a. Major species at pH 7.3 It is a conjugate base of a pheophytin a.
(21S,22S)-16-ethenyl-11-ethyl-3-methoxycarbonyl-12,17,21,26-tetramethyl-22-[3-oxo-3-[(E,7R,11R)-3,7,11,15-tetramethylhexadec-2-enoxy]propyl]-7,23,24,25-tetrazahexacyclo[18.2.1.15,8.110,13.115,18.02,6]hexacosa-1,3,5,8(26),9,11,13(25),14,16,18(24),19-undecaen-4-olate