porphyrin Chem.
(ˈpɔːfɪrɪn)
[a. G. porphyrin (Willstätter & Fritzsche 1909, in Ann. d. Chem. CCCLXXI. 33), f. haemato-porphyrin hæmatoporphyrin (s.v. hæmato-), f. Gr. πόρϕυρ-ος purple + -in -in1.]
Any of a large class of deeply-coloured red or purple fluorescent crystalline pigments that are substituted derivatives of porphin, many of which occur widely in nature, both in the free state and as complexes with metals (as in the hæms).
| 1910 Jrnl. Chem. Soc. XCVIII. i. 127 The phyllins are converted by acids into the corresponding porphyrins, compounds which do not contain magnesium. 1939 [see porphin]. 1949 Endeavour VIII. 83/1 In both [sc. adult and fœtal haemoglobin], the prosthetic group (to which the oxygen becomes attached) is the same iron porphyrin compound. 1950 Sci. News XV. 95 Porphyrin is the coloured part of hæmoglobin minus the iron. Porphyrin is easily detected because it shows an intense red fluorescence when held before an ultra-violet lamp. 1961 Lancet 22 July 175/1 A deficiency in purine synthesis could result, during porphyria, from the increased formation of porphyrins. 1970 Ambrose & Easty Cell Biol. vii. 228 The biologically important compounds chlorophyll, haemoglobin, and the cytochromes all contain a common cyclic structure, called a porphyrin, which consists of four pyrrole rings linked by methine bridges ({b1}CH{b2}). 1974 Sci. Amer. Dec. 73/1 In chlorophyll the central cavity of the ring is occupied by a magnesium atom... Porphyrin rings in the blood protein hemoglobin and in the cytochromes contain an atom of iron instead. |
Hence ˌporphyriˈnopathy (see quot. 1950).
| 1950 Thorpe's Dict. Appl. Chem. (ed. 4) X. 132/2 Porphyrinopathies, or diseases accompanied by abnormal porphyrin production or excretion. 1961 Ann. Rev. Med. XII. 258 In this review, the main porphyrinopathies will be listed using Waldenström's classification. |