The molecule is a cyclic tetrapyrrole that consists of porphyrin that has a cyclopentane ring fused to one of the pyrrole rings and the adjacent methine group. The parent of the class of phorbines.
7,23,24,25-tetrazahexacyclo[18.2.1.15,8.110,13.115,18.02,6]hexacosa-1,5,8(26),9,11,13(25),14,16,18,20(23)-decaene