Porphyrins - natural, pigments, porphin derivatives. When porphyrin molecules of atoms of metals are formed metalloporphyrins. Among them of great biological importance galataperform (gems)that are part of hemoglobin (see), myoglobin, cytochromes (see Enzymes) and others In the human body porphyrins can come with food or be synthesized from simple organic compounds.
Cm. also , Pigmentary exchange.

Porphyrins (from the Greek. porphyreos - crimson, purple) - natural pigments derived porphin. Porphin - organic compound composed of 4 pyrrole rings connected 4 malinovyj groups. Porphyrins are different from each other the composition of the side chains, replacing hydrogen atoms in perifericheskie located carbon atoms?-carbon) perlovich rings in a molecule produced. Depending on the nature and location of the side chains are obtained various isomers of porphyrins, and the basis of their classification was adopted Ethiopian containing two different side chains (4 groups bromide and 4 groups of ethyl). When there are two different side chains, the formation of four types (isomers) etiopien, of which in nature found only porphyrins I and III types. Incorporation into the porphyrin ring of metal (iron, magnesium, copper, vanadium) leads to the formation of metalloporphyrins. Among them of great biological importance galataperform, or gems that are part of hemoglobin (see), myoglobin, cytochromes, and some other chromoproteids, and magnitosfery used by plants for synthesis of chlorophyll. Porphyrins man and many animals are protoporphyrin type III (isomer IX), uroporfirii I and III types and coproporphyrin type I and III. Features of the structure of these porphyrins shown in the diagram. In the human body porphyrins can do with food or be synthesized from simple organic compounds (glycine, acetic acid).
Protoporphyrin contains the following side chains: 4 methyl groups, group-2 vinyl and 2 of the balance of propionic acid. It is formed in the bone marrow (300 mg/day) and is almost entirely used for education in heme biosynthesis of hemoglobin. Uroporfirii are the first porphyrins that occur in the body during the formation of heme. In the future, they become coproporphyrin. In the molecule of uroporphyrin contains 8 carboxyl groups under 4 balances and acetic 4 propionic acid residues. In the same molecule of coproporphyrin there are only 4 carboxyl group (the remains of the propionic acid). Formed in the body free uroporfirii types I and III and coproporphyrin types I and III are excreted in the urine and feces.
Entering the intestine with food hemoglobin subject to destruction, which is released protoporphyrin, then turning under the influence of bacteria in other porphyrins related to the type III (mesoporphyrin III and datareporting III). The amount of free protoporphyrin in 100 ml of blood ranges from 20 to 38 mcg, averaging 31 mcg. Urine for days out from the body of about 100-120 mcg (mainly coproporphyrin I and III). Daily allocation of porphyrins types I and III through the intestine is 300-400 mg.
Porphyrins are soluble in organic solvents, have a characteristic absorption spectrums, properties of bases and intense red fluorescence, while in solutions. Porphyrins are photosensitizers and so sharply increase the body's sensitivity to the action of the light rays.
Cm. also, Pigmentary exchange, Pigments.