thumb|right|class=skin-invert-image|Porphine, the parent of porphyrin
via PubMed
thumb|right|class=skin-invert-image|Porphine, the parent of porphyrin
Porphyrins ( ) are heterocyclic, macrocyclic, organic compounds, composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (). In vertebrates, an essential member of the porphyrin group is heme, which is a component of hemoproteins, whose functions include carrying oxygen in the bloodstream. In plants, an essential porphyrin derivative is chlorophyll, which is involved in light harvesting and electron transfer in photosynthesis.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).