Porphyrin

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porphyrin

 [por´fĭ-rin]
any of a group of iron- or magnesium-free cyclic tetrapyrrole derivatives, occurring universally in protoplasm, and forming the basis of the respiratory pigments of animals and plants; in combination with iron they form hemes. Examples include coproporphyrin, hematoporphyrin, protoporphyrin, and uroporphyrin. See also porphyria.

por·phin

, porphine (pōr'fin),
The unsubstituted cyclic tetrapyrrole nucleus that is the basis of the porphyrins.
See also: porphyrins. Compare: chlorin, phorbin, corrin.
Synonym(s): porphyrin

porphyrin

(pôr′fə-rĭn)
n.
Any of various organic compounds containing four pyrrole rings, occurring universally in protoplasm, and functioning as a metal-binding cofactor in hemoglobin, chlorophyll, and certain enzymes.

porphyrin

an organic compound consisting of four pyrrole rings linked by CH bridges with a heavy metal in the centre. Porphyrins form part of several important biological molecules. Examples include the haem group of HAEMOGLOBIN and MYOGLOBIN (see Fig. 258 ), chlorophyll (with magnesium) and cytochromes (with iron).

Porphyrin

A type of pigment found in living things, such as chlorophyll, that makes plants green and hemoglobin which makes blood red.
References in periodicals archive ?
The spectral data of the synthesized complexes (Table 1) revealed that the axially ligated Zr(IV) metal derivatives of porphyrin with different phenolates as an axial ligand showed hypsochromic shift (blue shift) and variation in intensities of absorption bands when compared to their respective free base porphyrin, due to incorporation of the metal ion along with phenolate in the porphyrin rings [1, 19].
Besides, it was found by Raman and infrared studies that the p-sulfonation on phenyl groups of [TPPS.sub.4] may alter the vibrations of C-C bonds between tetrapyrrole and phenyls and, to some extent, affect the [pi]-electron system on porphyrin ring (29).
As mentioned before, the metals, both valuable and those in the waste, are not easily leachable because they are immobilized in porphyrin rings. These rings can be destroyed by oxydation, through roasting and burning, but what is less known is that hydrogenation can accomplish the same thing.
Iron for instance, bound to the porphyrin ring as Fe(III) is involved in the catalytic breakdown of hydrogen peroxide, whereas when bound to the porphyrin ring in haemoglobin as Fe(II) it is involved in the transport of oxygen from lungs to tissues.
In humans, most of the iron is contained within the porphyrin ring of heme in proteins such as hemoglobin, myoglobin, catalase, peroxidases, and cytochromes, [3] as well as iron-sulfur proteins, such as NADH dehydrogenase and succinate dehydrogenase, in which iron is present in clusters with inorganic sulfur.
It was a nonprotein adjunct of the molecule, which consisted of a porphyrin ring, four small rings of atoms connected into a larger ring.
When the aluminium ion is inserted into the porphyrin ring, the N-H vibration frequency of free base porphyrin disappeared and the characteristic (Al-N) vibration frequency found at ~800 [cm.sup.-1] appeared, which indicated the formation of aluminium(III) porphyrin compounds [21].
Generally, the presence of In(III) metal in the porphyrin ring shifts the resonances of the porphyrin's protons to down-field accompanied by marginal changes in the pattern.