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词条 Porphyrin
释义

  1. Complexes of porphyrins

  2. Related species

  3. Natural formation

  4. Synthesis

     Biosynthesis  Laboratory synthesis 

  5. Applications

     Photodynamic therapy  Organic geochemistry   Toxicology  

  6. Potential applications

     Biomimetic catalysis  Molecular electronics  Supramolecular chemistry 

  7. See also

  8. Gallery

  9. References

  10. External links

{{Distinguish|Perforin}}{{Use dmy dates|date=June 2013}}Porphyrins ({{IPAc-en|ˈ|p|ɔːr|f|ər|ɪ|n}} {{respell|POR|fər|in}}) are a group of heterocyclic macrocycle organic compounds, composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (=CH−). The parent porphyrin is porphine, a rare chemical compound of exclusively theoretical interest. Substituted porphines are called porphyrins. With a total of 26 π-electrons, of which 18 π-electrons form a planar, continuous cycle, the porphyrin ring structure is often described as aromatic.[1][2] One result of the large conjugated system is that porphyrins typically absorb strongly in the visible region of the electromagnetic spectrum, i.e. they are deeply colored. The name "porphyrin" derives from the Greek word πορφύρα (porphyra), meaning purple.[3]

Metal complexes derived from porphyrins occur naturally. One of the best-known families of porphyrin complexes is heme, the pigment in red blood cells, a cofactor of the protein hemoglobin.

Complexes of porphyrins

Porphyrins are the conjugate acids of ligands that bind metals to form complexes. The metal ion usually has a charge of 2+ or 3+. A schematic equation for these syntheses is shown:

H2porphyrin + [MLn]2+ → M(porphyrinate)Ln−4 + 4 L + 2 H+, where M = metal ion and L = a ligand

A porphyrin without a metal-ion in its cavity is a free base. Some iron-containing porphyrins are called hemes. Heme-containing proteins, or hemoproteins, are found extensively in nature. Hemoglobin and myoglobin are two O2-binding proteins that contain iron porphyrins. Various cytochromes are also hemoproteins.

Related species

A benzoporphyrin is a porphyrin with a benzene ring fused to one of the pyrrole units. e.g. verteporfin is a benzoporphyrin derivative.[4]

Several other heterocycles are related to porphyrins. These include corrins, chlorins, bacteriochlorophylls, and corphins. Chlorins (2,3-dihydroporphyrin) are more reduced, contain more hydrogen than porphyrins, i.e. one pyrrole has been converted to a pyrroline. This structure occurs in chlorophylls. 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.{{citation needed|date=October 2017}}

Natural formation

A geoporphyrin, also known as a petroporphyrin, is a porphyrin of geologic origin.[5] They can occur in crude oil, oil shale, coal, or sedimentary rocks.[5][6] Abelsonite is possibly the only geoporphyrin mineral, as it is rare for porphyrins to occur in isolation and form crystals.[7]

Synthesis

Biosynthesis

In non-photosynthetic eukaryotes such as animals, insects, fungi, and protozoa, as well as the α-proteobacteria group of bacteria, the committed step for porphyrin biosynthesis is the formation of δ-aminolevulinic acid (δ-ALA, 5-ALA or dALA) by the reaction of the amino acid glycine with succinyl-CoA from the citric acid cycle. In plants, algae, bacteria (except for the α-proteobacteria group) and archaea, it is produced from glutamic acid via glutamyl-tRNA and glutamate-1-semialdehyde. The enzymes involved in this pathway are glutamyl-tRNA synthetase, glutamyl-tRNA reductase, and glutamate-1-semialdehyde 2,1-aminomutase. This pathway is known as the C5 or Beale pathway.

Two molecules of dALA are then combined by porphobilinogen synthase 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.

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:

EnzymeLocationSubstrateProductChromosomeECOMIMDisorder
ALA synthase Mitochondrion Glycine, succinyl CoA δ-Aminolevulinic acid 3p21.1 2.3.1.37 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=125290 125290] X-linked dominant protoporphyria, X-linked sideroblastic anemia
ALA dehydratase Cytosol δ-Aminolevulinic acid Porphobilinogen 9q34 4.2.1.24 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=125270 125270] aminolevulinic acid dehydratase deficiency porphyria
PBG deaminase Cytosol Porphobilinogen Hydroxymethyl bilane 11q23.3 2.5.1.61 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=176000 176000] acute intermittent porphyria
Uroporphyrinogen III synthase Cytosol Hydroxymethyl bilane Uroporphyrinogen III 10q25.2-q26.3 4.2.1.75 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=606938 606938] congenital erythropoietic porphyria
Uroporphyrinogen III decarboxylase Cytosol Uroporphyrinogen III Coproporphyrinogen III 1p34 4.1.1.37 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=176100 176100] porphyria cutanea tarda, hepatoerythropoietic porphyria
Coproporphyrinogen III oxidase Mitochondrion Coproporphyrinogen III Protoporphyrinogen IX 3q12 1.3.3.3 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=121300 121300] hereditary coproporphyria
Protoporphyrinogen oxidase Mitochondrion Protoporphyrinogen IX Protoporphyrin IX 1q22 1.3.3.4 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=600923 600923] variegate porphyria
Ferrochelatase Mitochondrion Protoporphyrin IX Heme 18q21.3 4.99.1.1 [https://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=177000 177000] erythropoietic protoporphyria

Laboratory synthesis

One of the most common syntheses for porphyrins is based on work by Paul Rothemund.[8][9] His techniques underpin more modern synthesis such as those described by Adler and Longo.[10] The synthesis of simple porphyrins such as meso-tetraphenylporphyrin (H2TPP) is also commonly done in university teaching labs.[11]

The Rothemund synthesis is a condensation and oxidation starting with pyrrole and an aldehyde. In solution-phase synthesis, acidic conditions are essential;{{citation needed|date=October 2011}} formic acid, acetic acid, and propionic acid are typical reaction solvents, or p-toluenesulfonic acid or various Lewis acids can be used with a non-acidic solvent. A large amount of side-product is formed and is removed, usually by recrystallization or chromatography.

Green chemistry variants have been developed in which the reaction is performed with microwave irradiation using reactants adsorbed on acidic silica gel[12] or at high temperature in the gas phase.[13] In these cases, no additional acid is required.

Applications

The main role of porphyrins is their support of aerobic life.

Photodynamic therapy

Porphyrins have been evaluated in the context of photodynamic therapy (PDT) since they strongly absorb light, which is then converted to energy and heat in the illuminated areas.[14] This technique has been applied in macular degeneration using verteporfin.[15]

PDT is considered a noninvasive cancer treatment, involving the interaction between light of a determined frequency, a photo-sensitizer, and oxygen. This interaction produces the formation of a highly reactive oxygen species (ROS), usually singlet oxygen, as well as superoxide anion, free hydroxyl radical, or hydrogen peroxide.[16]

These high reactive oxygen species react with susceptible cellular organic biomolecules such as; lipids, aromatic amino acids, and nucleic acid heterocyclic bases, to produce oxidative radicals that damage the cell, possibly inducing apoptosis or even necrosis.[17]

Bacteria have been shown to produce porphyrins endogenously[18] as byproducts in heme biosynthesis, and these can be used in phototherapy to treat bacterial infections, such as acne.

Organic geochemistry

The field of organic geochemistry, the study of the impacts and processes that organisms have had on the Earth, had its origins in the isolation of porphyrins from petroleum. This finding helped establish the biological origins of petroleum. Petroleum is sometimes "fingerprinted" by analysis of trace amounts of nickel and vanadyl porphyrins.

Chlorophyll is a magnesium porphyrin, and heme is an iron porphyrin, but neither porphyrin is present in petroleum.{{Citation needed|date=January 2011}} On the other hand, nickel and vanadyl porphyrins could be related to catalytic molecules from bacteria that feed primordial hydrocarbons.

Toxicology

Heme biosynthesis is used as biomarker in environmental toxicology studies. While excess production of porphyrins indicate organochlorine exposure, lead inhibits ALA dehydratase enzyme.[19]

Potential applications

Biomimetic catalysis

Although not commercialized, metalloporphyrin complexes are widely studied as catalysts for the oxidation of organic compounds. Particularly popular for such laboratory research are complexes of meso-tetraphenylporphyrin and octaethylporphyrin. Complexes with Mn, Fe, and Co catalyze a variety of reactions of potential interest in organic synthesis. Some complexes emulate the action of various heme enzymes such as cytochrome P450, lignin peroxidase,[20][21]

Molecular electronics

Porphyrin-based compounds are of interest as possible components of molecular electronics and photonics.[22] Synthetic porphyrin dyes that are incorporated in prototype dye-sensitized solar cells.[23][24]

Phthalocyanines, which are structurally related to porphyrins, are used in commerce as dyes and catalysts, but porphyrins are not.

Supramolecular chemistry

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.[26] A guest-free base porphyrin is bound to the center by coordination with its four-pyridine substituents.

See also

  • A porphyrin-related disease: porphyria
  • Porphyrin coordinated to iron: heme
  • A heme-containing group of enzymes: Cytochrome P450
  • Porphyrin coordinated to magnesium: chlorophyll
  • The one-carbon-shorter analogues: corroles, including vitamin B12, which is coordinated to a cobalt
  • Corphins, the highly reduced porphyrin coordinated to nickel that binds the Cofactor F430 active site in methyl coenzyme M reductase (MCR)
  • Nitrogen-substituted porphyrins: phthalocyanine

Gallery

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References

1. ^{{cite journal |title= Deciphering aromaticity in porphyrinoids via adaptive natural density partitioning |first1= Alexander S. |last1= Ivanov |first2= Alexander I. |last2= Boldyrev |journal= Organic & Biomolecular Chemistry |year= 2014 |volume= 12 |issue= 32 |pages= 6145–6150 |doi= 10.1039/C4OB01018C |pmid= 25002069 }}
2. ^{{cite journal |first= Timothy D. |last= Lash |journal= Journal of Porphyrins and Phthalocyanines |volume= 15 |issue= 11n12 |pages= 1093–1115 |year= 2011 |doi= 10.1142/S1088424611004063 |title= Origin of aromatic character in porphyrinoid systems }}
3. ^{{cite web|last1=Harper|first1=Douglas|last2=Buglione|first2=Drew Carey|title=porphyria (n.)|url=http://www.etymonline.com/index.php?allowed_in_frame=0&search=porphyrin&searchmode=none|website=The Online Etymology Dictionary|accessdate=14 September 2014}}
4. ^{{Cite journal | doi = 10.2165/00002512-200016020-00005 | last1 = Scott | first1 = L. J. | last2 = Goa | first2 = K. L. | title = Verteporfin | journal = Drugs & Aging | volume = 16 | issue = 2 | pages = 139–146; discussion 146–8 | year = 2000 | pmid = 10755329}}
5. ^1 {{cite book|title=The Porphyrin Handbook|publisher=Elsevier|isbn=9780123932006|url=https://books.google.com/books?id=Ci7rIe0Ohn8C&pg=PA381|editor=Karl M. Kadish|page=381|date=1999}}
6. ^{{cite journal|ref=harv|last1=Zhang|first1=Bo|last2=Lash|first2=Timothy D.|title=Total synthesis of the porphyrin mineral abelsonite and related petroporphyrins with five-membered exocyclic rings|journal=Tetrahedron Letters|date=September 2003|volume=44|issue=39|page=7253|doi=10.1016/j.tetlet.2003.08.007}}
7. ^{{cite journal|ref=harv|last1=Mason|first1=G. M.|last2=Trudell|first2=L. G.|last3=Branthaver|first3=J. F.|title=Review of the stratigraphic distribution and diagenetic history of abelsonite|journal=Organic Geochemistry|year=1989|volume=14|issue=6|page=585|doi=10.1016/0146-6380(89)90038-7}}
8. ^{{cite journal | author = P. Rothemund | title = A New Porphyrin Synthesis. The Synthesis of Porphin | year = 1936 | journal = J. Am. Chem. Soc. | volume = 58 | issue = 4 | pages = 625–627 | doi = 10.1021/ja01295a027}}
9. ^{{cite journal | author = P. Rothemund | title = Formation of Porphyrins from Pyrrole and Aldehydes | year = 1935 | journal = J. Am. Chem. Soc. | volume = 57 | issue = 10 | pages = 2010–2011 | doi=10.1021/ja01313a510}}
10. ^{{cite journal |author1=A. D. Adler |author2=F. R. Longo |author3=J. D. Finarelli |author4=J. Goldmacher |author5=J. Assour |author6=L. Korsakoff | title = A simplified synthesis for meso-tetraphenylporphine | year = 1967 | journal = J. Org. Chem. | volume = 32 | issue = 2 | pages = 476 | doi = 10.1021/jo01288a053}}
11. ^{{cite journal | title = Microscale Synthesis and 1H NMR Analysis of Tetraphenylporphyrins |author1=Falvo, RaeAnne E. |author2=Mink, Larry M. |author3=Marsh, Diane F. | journal = J. Chem. Educ. | volume = 1999 | issue = 76 | pages = 237–239 |doi= 10.1021/ed076p237 | year = 1999 }}
12. ^{{cite journal |journal= Synth. Commun. |year= 1992 |volume= 22 |issue= 8 |pages= 1137–1142 |doi= 10.1080/00397919208021097 |author1=Petit, A. |author2=Loupy, A. |author3=Maiuard, P. |author4=Momenteau, M. |title= Microwave Irradiation in Dry Media: A New and Easy Method for Synthesis of Tetrapyrrolic Compounds }}
13. ^{{cite journal |title= Synthesis of meso substituted porphyrins in air without solvents or catalysts |journal= Chem. Commun. |year= 1997 |pages= 2117–2118 |doi= 10.1039/A704600F |author1=Drain, C. M. |author2=Gong, X. |issue= 21 }}
14. ^{{cite encyclopedia|title=Porphyrin conjugates for cancer therapy|authors=Giuntini, Francesca; Boyle, Ross; Sibrian-Vazquez, Martha; Vicente, M. Graca H.|editors=Kadish, Karl M.; Smith, Kevin M.; Guilard, Roger|encyclopedia=Handbook of Porphyrin Science|year=2014|volume=27|pages=303–416|doi=}}
15. ^{{cite journal |vauthors=Wormald R, Evans J, Smeeth L, Henshaw K |title=Photodynamic therapy for neovascular age-related macular degeneration |journal=Cochrane Database Syst Rev |volume= |issue=3 |pages=CD002030 |year=2007 |pmid=17636693 |doi=10.1002/14651858.CD002030.pub3 |url=http://researchonline.lshtm.ac.uk/11443/1/Wormald_et_al-2005-The_Cochrane_library.pdf}}
16. ^Price, M., Terlecky, S. R. and Kessel, D. (2009), A Role for Hydrogen Peroxide in the Pro‐apoptotic Effects of Photodynamic Therapy. Photochemistry and Photobiology, 85: 1491-1496. doi:10.1111/j.1751-1097.2009.00589.x
17. ^Singh, S., Aggarwal, A., N. V. S. Dinesh K. Bhupathiraju, Arianna, G., Tiwari, K., & Drain, C. M. (2015). Glycosylated Porphyrins, Phthalocyanines, and Other Porphyrinoids for Diagnostics and Therapeutics. Chemical Reviews, 115(18), 10261-10306. doi:10.1021/acs.chemrev.5b00244
18. ^{{cite journal|author1=Fyrestam J|author2=Bjurshammar N|author3=Paulsson E|author4=Johannsen A|author5=Östman C|title=Determination of porphyrins in oral bacteria by liquid chromatography electrospray ionization tandem mass spectrometry|journal=Analytical and Bioanalytical Chemistry|date=September 2015|volume=407|issue=23|pages=7013–7023|doi=10.1007/s00216-015-8864-2|pmid=26168965|pmc=4551553}}
19. ^{{Cite book|title=Principles of Ecotoxicology|last=Walker|first=C. H.|last2=Silby|first2=R. M.|last3=Hopkin|first3=S. P.|last4=Peakall|last5=D.B.|publisher=CRC Press|year=2012|isbn=978-1-4665-0260-4|location=Boca Raton, FL|pages=182|quote=|via=}}
20. ^{{cite journal|last1=Zucca|first1=Paolo|last2=Rescigno|first2=Antonio|last3=Rinaldi|first3=Andrea C.|last4=Sanjust|first4=Enrico|title=Biomimetic metalloporphines and metalloporphyrins as potential tools for delignification: Molecular mechanisms and application perspectives|journal=Journal of Molecular Catalysis A: Chemical|date=July 2014|volume=388–389|pages=2–34|doi=10.1016/j.molcata.2013.09.010}}
21. ^{{cite book|last1=Guilard|first1=edited by Karl M. Kadish, Kevin M. Smith & Roger|title=Handbook of porphyrin science with applications to chemistry, physics, materials science, engineering, biology and medicine|date=2012|publisher=World Scientific|location=Singapore|isbn=9789814335492}}
22. ^{{cite journal|title=Synthesis of π-extended porphyrins via intramolecular oxidative coupling|authors=By Lewtak, Jan P.; Gryko, Daniel T.|journal=Chemical Communications|year=2012|volume=48|issue=81|pages=10069–10086|doi=10.1039/c2cc31279d|pmid=22649792|bibcode=2008ChCom..44.5292T}}
23. ^{{cite journal | journal = Journal of Porphyrins and Phthalocyanines | year = 2010 | volume = 14 | pages = 759–792 | doi= 10.1142/S1088424610002689 | title = Porphyrins and phthalocyanines in solar photovoltaic cells |author1=Michael G. Walter |author2=Alexander B. Rudine |author3=Carl C. Wamser | issue = 9}}
24. ^{{cite journal | journal = Science | year = 2011 | volume = 334 | pages = 629–634 | title = Porphyrin-Sensitized Solar Cells with Cobalt (II/III)–Based Redox Electrolyte Exceed 12 Percent Efficiency |author1=Aswani Yella |author2=Hsuan-Wei Lee |author3=Hoi Nok Tsao |author4=Chenyi Yi |author5=Aravind Kumar Chandiran |author6=Md.Khaja Nazeeruddin |author7=Eric Wei-Guang Diau |author8=Chen-Yu Yeh |author9=Shaik M Zakeeruddin |author10=Michael Grätzel | issue = 6056|bibcode = 2011Sci...334..629Y |doi = 10.1126/science.1209688 | pmid = 22053043 }}
25. ^{{cite journal|doi=10.1039/C5CC04940G |pmid=26278062 |title=Heat-induced formation of one-dimensional coordination polymers on Au(111): An STM study |journal=Chem. Commun. |volume=51 |issue=77 |pages=14473–6 |year=2015 |last1=Pham |first1=Tuan Anh |last2=Song |first2=Fei |last3=Alberti |first3=Mariza N. |last4=Nguyen |first4=Manh-Thuong |last5=Trapp |first5=Nils |last6=Thilgen |first6=Carlo |last7=Diederich |first7=François |last8=Stöhr |first8=Meike }}
26. ^1 {{cite journal | journal = Angew. Chem. Int. Ed. Engl. | year = 1995 | volume = 34 | pages = 1096–1099 | doi = 10.1002/anie.199510961 | title = Assembly and Crystal Structure of a Photoactive Array of Five Porphyrins | author = Sally Anderson, Harry L. Anderson, Alan Bashall, Mary McPartlin, Jeremy K. M. Sanders | issue = 10}}

External links

{{Commons category|Porphyrins}}
  • Journal of Porphyrins and Phthalocyanines
  • Handbook of Porphyrin Science
  • Porphynet – an informative site about porphyrins and related structures
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5 : Biomolecules|Metabolism|Photosynthetic pigments|Chelating agents|Porphyrins
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