Structure of porphine, the simplest porphyrin.

Space-filling model of porphyrin

A porphyrin is a heterocyclic macrocycle derived from four pyrrole-like subunits interconnected via their α carbon atoms via methine bridges (=CH-). The macrocycle, therefore, is a highly conjugated system, and is consequently deeply coloured—the name porphyrin comes from a Greek word for purple. The macrocycle has 22 pi electrons. The parent porphyrin is porphine, and substituted porphines are called porphyrins. Many porphyrins occur in nature, such as in green leaves and red blood cells, and in bio-inspired synthetic catalysts and devices. Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links Download high-resolution version (693x653, 92 KB) 3D representation of porphyrin. ... Image File history File links Download high-resolution version (693x653, 92 KB) 3D representation of porphyrin. ... A macrocycle is, as defined by IUPAC, In the chemical literature, organic chemists may consider any molecule containing a ring of seven, fifteen, or any arbitrarily large number of atoms to be macrocyclic. ... Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... -1... A chemically conjugated system, is a system of atoms covalently bonded with alternating single and double bonds (e. ... Not to be confused with Violet (color). ... Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ... Chemical structure of free porphin Porphin, sometimes spelled porphine, is the parent chemical compound for types of biochemically significant compounds called porphyrins. ... A blood cell is any cell of any type normally found in blood. ...

Complexes of porphyrins and related molecules

Porphyrins bind metals to form complexes. The metal ion, usually with a charge of 2+ or 3+, resides in the central N₄ cavity formed by the loss of two protons. Most metals can be inserted. A schematic equation for these syntheses is shown: For alternative meanings see metal (disambiguation). ... Synthesis of copper(II)-tetraphenylporphine, a metal complex, from tetraphenylporphine and copper(II) acetate monohydrate. ... An electrostatic potential map of the nitrate ion (NO3−). Areas coloured red are lower in energy than areas colored yellow An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ...

H₂porphyrin + [ML_n]²⁺ → M(porphyrinate)L_n-4 + 4 L + 2 H⁺

A porphyrin in which no metal is inserted in its cavity is sometimes called a free base. Some iron-containing porphyrins are called hemes; and heme-containing proteins, or hemoproteins, are found extensively in Nature. Hemoglobin and myoglobin are two O₂-binding proteins that contain iron porphyrins. Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... A hemoprotein (also haemoprotein), or heme protein, is a metalloprotein containing a heme prosthetic group, either covalently or noncovalently bound to the protein itself. ... Structure of hemoglobin. ... An X-ray diffraction image for the protein myoglobin. ...

Related to porphyrins are several other heterocycles, including corrins, chlorins, bacteriochlorophylls, and corphins. Chlorins (2,3-dihydroporphyrin) are more reduced, that contain more hydrogen, than porphyrins, featuring a pyrroline subunit. This structure occurs in chlorophyll. Replacement of two of the four pyrrolic subunits with pyrrolinic subunits results in either a bacteriochlorin (as found in some photosynthetic bacteria) or an isobacteriochlorin, depending on the relative positions of the reduced rings. Some porphyrin derivatives follow Hückel's rule, but most do not. A corrin is a polyaromatic ring related to the porphyrin ring in hemoglobin, consisting of 4 pyrrole subunits, joined on opposite sides by a C-CH3 methylene link, on one side by a C-H methylene link, and with the two of the pyrroles joined directly. ... In organic chemistry, a chlorin is a large heterocyclic aromatic ring consisting, at the core, of 3 pyrroles and one reduced pyrrole coupled through 4 methine linkages. ... Bacteriochlorophylls are photosynthetic pigments that occur in various bacteria. ... The Ferrari F430 is a sports car automobile, the replacement for the Ferrari 360. ... In organic chemistry, a chlorin is a large heterocyclic aromatic ring consisting, at the core, of 3 pyrroles and one reduced pyrrole coupled through 4 methine linkages. ... Chlorophyll gives leaves their green color Space-filling model of the chlorophyll molecule Chlorophyll is a green pigment found in most plants, algae, and cyanobacteria. ... Bacteriochlorophylls are photosynthetic pigments that occur in various bacteria. ... Leaf. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... In organic chemistry, Hückels rule estimates whether a planar ring molecule will have aromatic properties. ...

Laboratory synthesis

One of the more common syntheses for porphyrins is based on work by Paul Rothemund.^[1][2] His techniques underpin more modern syntheses such as those described by Alder and Longo.^[3] The synthesis of simple porphyrins such as meso-tetraphenylporphyrin is also commonly done in university teaching labs.^[4]

In this method, porphyrins are assembled from pyrrole and substituted aldehydes. Acidic conditions are essential; formic acid, acetic acid, and propionic acid are typical reaction solvents, or p-toluenesulfonic acid can be used with a non-acidic solvent. Lewis acids such as boron trifluoride etherate and ytterbium triflate have also been known to catalyse porphyrin formation. A large amount of side product is formed and is removed, usually by chromatography. Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... An aldehyde. ... Tosyl Group with a generic R Group attached (where R can be anything, typically a carbon). ...

Image File history File links Size of this preview: 800 × 305 pixelsFull resolution (1141 × 435 pixel, file size: 18 KB, MIME type: image/png) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Biosynthesis

The "committed step" for porphyrin biosynthesis is the formation of D-aminolevulinic acid (dALA) by the reaction of the amino acid glycine and succinyl-CoA, from the citric acid cycle. Two molecules of dALA combine to give porphobilinogen (PBG), which contains a pyrrole ring. Four PBGs are then combined through deamination into hydroxymethyl bilane (HMB), which is hydrolysed to form the circular tetrapyrrole uroporphyrinogen III. This molecule undergoes a number of further modifications. Intermediates are used in different species to form particular substances, but, in humans, the main end-product protoporphyrin IX is combined with iron to form heme. Bile pigments are the breakdown products of heme. Biosynthesis is a phenomenon where chemical compounds are produced from simpler reagents. ... D-Aminolevulinic acid (dALA or δ-ALA) is the first compound in the porphyrin synthesis pathway. ... Phenylalanine is one of the standard amino acids. ... For the plant, see Glycine (plant). ... Categories: Biochemistry stubs ... Overview of the citric acid cycle The citric acid cycle (also known as the tricarboxylic acid cycle, the TCA cycle, or the Krebs cycle, after Hans Adolf Krebs who identified the cycle) is a series of chemical reactions of central importance in all living cells that use oxygen as part... Porphobilinogen is a pyrrole involved in porphyrin metabolism. ... Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... Deamination is the removal of an amine group from a molecule. ... Hydroxymethylbilane is a molecule involved in the metabolism of porphyrin. ... Hydrolysis is a chemical reaction or process in which a molecule is split into two parts by reacting with a molecule of water, which has the chemical formula H2O. One of the parts gets an OH- from the water molecule and the other part gets an H+ from the water. ... Uroporphyrinogens are tetrapyrroles with four propionic acid groups and four acetic acid groups. ... Protoporphyrins are tetrapyrroles containing the following side chains: methyl (4) propionic acid (2) vinyl (2) In the metabolism of porphyrin, protoporphyrin IX is created by the enzyme protoporphyrinogen oxidase, and the enzyme ferrochelatase converts it into heme. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ...

The following scheme summarizes the biosynthesis of porphyrins, with references by EC number and the OMIM database. The porphyria associated with the deficiency of each enzyme is also shown: The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... It has been suggested that Acute intermittent porphyria be merged into this article or section. ...

Image File history File links Heme synthesis File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... It has been suggested that Cytoplast be merged into this article or section. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) (from Greek μιτος or mitos, thread + χονδριον or khondrion, granule) is a membrane-enclosed organelle, found in most eukaryotic cells. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... In biochemistry, a substrate is a molecule upon which an enzyme acts. ... Figure 1: A representation of a condensed eukaryotic chromosome, as seen during cell division. ... The Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... It has been suggested that Acute intermittent porphyria be merged into this article or section. ... ALA synthase The rate-limiting enzyme in porphyrin and heme biosynthesis is ALA synthase, the enzyme that catalyses glycine and succinyl-CoA into D-Aminolevulinic acid. ... For the plant, see Glycine (plant). ... Succinyl-CoA (coenzyme A is grey) Succinyl-Coenzyme A, generally abbreviated as Succinyl-CoA is a combination of succinic acid and coenzyme A. Source It is an important intermediate in the citric acid cycle, where is it synthetised from α-Ketoglutarate by α-ketoglutarate dehydrogenase through decarboxylation. ... Porphobilinogen synthase (or ALA dehydratase, or Aminolevulinate dehydratase) synthesizes porphobilinogen through the asymmetric condensation of two molecules of aminolevulinic acid. ... D-Aminolevulinic acid (dALA or δ-ALA) is the first compound in the porphyrin synthesis pathway. ... Porphobilinogen deaminase (or hydroxymethylbilane synthase) is an enzyme involved in the third step of the metabolism of porphyrin, converting porphobilinogen into hydroxymethyl bilane. ... Porphobilinogen is a pyrrole involved in porphyrin metabolism. ... Acute intermittent porphyria (AIP) is a rare metabolic disorder that is characterized by a deficiency of the enzyme, porphobilinogen deaminase (PBG-D), also known as uroporphyrinogen I-synthase. ... Uroporphyrinogen III synthase is an enzyme involved in the fourth step of porphyrin metabolism, involved in the converstion of hydroxymethyl bilane into uroporphyrinogen III. Category: ... Hydroxymethylbilane is a molecule involved in the metabolism of porphyrin. ... The porphyrias are inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway (also called porphyrin pathway). ... UroD drawn from PDB 1URO. Uroporphyrinogen III decarboxylase (UroD) is a homodimeric enzyme (EC 4. ... Uroporphyrinogens are tetrapyrroles with four propionic acid groups and four acetic acid groups. ... The porphyrias are inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway (also called porphyrin pathway). ... Coproporphyrinogen III oxidase is an enzyme involved in the sixth step of porphyrin metabolism, converting coproporphyrinogen III to protoporphyrinogen IX. Category: ... Coproporphyrinogens are tetrapyrroles with four propionic acid groups and an equal number of substituted methyls. ... The porphyrias are inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway (also called porphyrin pathway). ... Protoporphyrinogen oxidase (EC 1. ... Protoporphyrins are tetrapyrroles containing the following side chains: methyl (4) propionic acid (2) vinyl (2) In the metabolism of porphyrin, protoporphyrin IX is created by the enzyme protoporphyrinogen oxidase, and the enzyme ferrochelatase converts it into heme. ... The porphyrias are inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway (also called porphyrin pathway). ... Ferrochelatase is an enzyme involved in the eighth step of porphyrin metabolism, converting protoporphyrin IX into heme. ... Protoporphyrins are tetrapyrroles containing the following side chains: methyl (4) propionic acid (2) vinyl (2) In the metabolism of porphyrin, protoporphyrin IX is created by the enzyme protoporphyrinogen oxidase, and the enzyme ferrochelatase converts it into heme. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... The porphyrias are inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway (also called porphyrin pathway). ...

Applications

Although natural porphyin complexes are essential for life, synthetic porphyrins and their complexes have limited utility. Complexes of meso-tetraphenylporphyrin, e.g. the iron-(III) chloride complex (TPPFeCl) catalyse a variety of reactions in organic chemistry, but none are of practical value. Porphyrin-based compounds are of interest in molecular electronics and supramolecular building blocks. Phthalocyanines, which are structurally related to porphyrins, are used in commerce as dyes and catalysts. Synthetic porphyrin dyes that are incorporated in the design of solar cells are the subject of ongoing research. See Dye-sensitized solar cells. Organic chemistry is a specific discipline within chemistry which involves the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of chemical compounds consisting of primarily carbon and hydrogen, which may contain any number of other elements, including nitrogen, oxygen, halogens as well... Molecular electronics (sometimes called moletronics) is a branch of applied physics which aims at using molecules as passive (e. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Dye-sensitized solar cells are photoelectrochemical cells that use photo-sensitization of wide-band-gap mesoporous oxide semiconductors. ...

Supramolecular chemistry

An example of a porphyrins involved in host-guest chemistry reported by Sanders and coworkers in Angew. Chem., Int. Ed. Engl. 1995, 34, 1096-1099.

Porphyrins are often used to construct structures in supramolecular chemistry. These systems take advantage of the Lewis acidity of the metal, typically zinc. An example of a host-guest complex that was constructed from a macrocycle composed of four porphyrins.^[5] A guest-free base porphyrin is bound to the center by coordination with its four pyridine sustituents. Image File history File linksMetadata Size of this preview: 642 × 600 pixelsFull resolution (741 × 692 pixel, file size: 266 KB, MIME type: image/jpeg) This is a picture generated from crystal structure data reported by Sally Anderson, Harry L. Anderson, Alan Bashall, Mary McPartlin, Jeremy K. M. Sanders in Angewandte... Image File history File linksMetadata Size of this preview: 642 × 600 pixelsFull resolution (741 × 692 pixel, file size: 266 KB, MIME type: image/jpeg) This is a picture generated from crystal structure data reported by Sally Anderson, Harry L. Anderson, Alan Bashall, Mary McPartlin, Jeremy K. M. Sanders in Angewandte... In supramolecular chemistry, host-guest chemistry describes complexes that are composed of two or more molecules or ions held together in unique structural relationships by hydrogen bonding or by ion pairing or by Van der Waals force other than those of full covalent bonds. ... Supramolecular chemistry refers to the area of chemistry which focuses on the noncovalent bonding interactions of molecules. ... In supramolecular chemistry, host-guest chemistry describes complexes that are composed of two or more molecules or ions held together in unique structural relationships by hydrogen bonding or by ion pairing or by Van der Waals force other than those of full covalent bonds. ... A macrocycle is, as defined by IUPAC, In the chemical literature, organic chemists may consider any molecule containing a ring of seven, fifteen, or any arbitrarily large number of atoms to be macrocyclic. ...

See also

• A porphyrin-related disease: porphyria
• Porphyrin coordinated to iron: heme
• Porphyrin coordinated to magnesium: chlorophyll
• The one-carbon-shorter analogues: corroles
• Corphins, the highly reduced porphyrin that binds the F430 active site in methyl coenzyme M reductase (MCR)

It has been suggested that Acute intermittent porphyria be merged into this article or section. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... Chlorophyll gives leaves their green color Space-filling model of the chlorophyll molecule Chlorophyll is a green pigment found in most plants, algae, and cyanobacteria. ... Corrole is an aromatic ring structure compound similar as porphyrin and vitamin B12. ... The Ferrari F430 is a sports car automobile, the replacement for the Ferrari 360. ... Methyl-coenzyme M reductase (MCR) is an enzyme that occurs in archaea and catalyzes the formation of methane by combining the hydrogen donor coenzyme B and the methyl donor coenzyme M. The enzyme has two active sites, each occupied by the nickel-containing F430 cofactor. ...

References

The Journal of the American Chemical Society (usually abbreviated as , or JACS), is a peer-reviewed scientific journal, published since 1879 by the American Chemical Society. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... The Journal of the American Chemical Society (usually abbreviated as , or JACS), is a peer-reviewed scientific journal, published since 1879 by the American Chemical Society. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... The Journal of Organic Chemistry (abbreviated as ) is a scientific journal for original contributions of fundamental research in organic and bioorganic chemistry. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

External links

• Porphynet - an informative site about porphyrins and related structures