SMILES: CC1=C(C2=CC3=NC(=CC4=NC(=CC5=C(C(=C(N5)C=C1N2)C=C)C)C(=C4CCC(=O)[O-])C)C(=C3C)CCC(=O)[O-])C=C
Description: The molecule is the dicarboxylate anion of protoporphyrin, obtained by deprotonation of both carboxy groups. It is a conjugate base of a protoporphyrin.