a dark red, photosensitive pigment consisting of four pyrrole rings linked by single carbon atoms: a component of chlorophyll, heme, and vitamin B12.
Origin of porphyrin
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any of a group of pigments occurring widely in animal and plant tissues and having a heterocyclic structure formed from four pyrrole rings linked by four methylene groups
Word Origin for porphyrin
C20: from Greek porphura purple, referring to its colour
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Any of various heterocyclic compounds, derived from pyrrole, that occur universally in protoplasm, contain a central metal atom, and provide the foundation structure for hemoglobin, chlorophyll, and certain enzymes.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Any of various organic pigments containing four pyrrole rings bonded to one another. The rings form the corners of a large flat square, in the middle of which is a cavity that often contains a metal atom. Porphyrins occur universally in protoplasm and function with bound metals such as iron in hemoglobin and magnesium in chlorophyll.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.