Main Entry:

por·phy·rin

Pronunciation:

\ˈpȯr-fə-rən\

Function:

noun

Etymology:

International Scientific Vocabulary, from Greek porphyra purple

Date:

1910

: any of various compounds with a macrocyclic structure that consists essentially of four pyrrole rings joined by four =CH− groups ; especially : one (as chlorophyll or hemoglobin) containing a central metal atom and usually exhibiting biological activity