Definition: A group of compounds containing the porphin structure, four pyrrole rings connected by methine bridges in a cyclic configuration to which a variety of side chains are attached. The nature of the side chain is indicated by a prefix, as uroporphyrin, hematoporphyrin, etc. The porphyrins, in combination with iron, form the heme component in biologically significant compounds such as hemoglobin and myoglobin.
Talaporfin [ Laserphyrin,N-aspartyl chlorin e6,N-aspartylchlorin e6,NPe6,mono-L-aspartyl chlorin e6,monoaspartyl chlorin e6,talaporfin sodium ] effective tumor localizer that brings about the selective degradation of tumor tissue following light exposure; structure given in first source