{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 424734311 | ImageFile = phytoene.png | ImageSize = 250px | ImageName = Skeletal formula | ImageFile1 = Phytoene-3D-balls-(rotated).png | ImageSize1 = 250px | ImageName1 = Ball-and-stick model | IUPACName = 15-''cis''-7,8,11,12,7′,8′,11′,12′-Octahydro-ψ,ψ-carotene | SystematicName=(6''E'',10''E'',14''E'',16''Z'',18''E'',22''E'',26''E'')-2,6,10,14,19,23,27,31-Octamethyldotriaconta-2,6,10,14,16,18,22,26,30-nonaene | OtherNames=15-''cis''-Phytoene |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|correct|??}} | CASNo=13920-14-4 | PubChem=9963391 | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 27787 | UNII_Ref = {{fdacite|changed|FDA}} | UNII = 876K2ZK1OF | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 8138988 | KEGG_Ref = {{keggcite|changed|kegg}} | KEGG = C05421 | SMILES=CC(=CCC/C(=C/CC/C(=C/CC/C(=C/C=C\C=C(/C)\CC/C=C(\C)/CC/C=C(\C)/CCC=C(C)C)/C)/C)/C)C | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C40H64/c1-33(2)19-13-23-37(7)27-17-31-39(9)29-15-25-35(5)21-11-12-22-36(6)26-16-30-40(10)32-18-28-38(8)24-14-20-34(3)4/h11-12,19-22,27-30H,13-18,23-26,31-32H2,1-10H3/b12-11-,35-21+,36-22+,37-27+,38-28+,39-29+,40-30+ | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = YVLPJIGOMTXXLP-BHLJUDRVSA-N }} |Section2={{Chembox Properties | C=40 | H=64 | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= }} |Section3={{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt = }} }}
'''Phytoene''' ({{IPAc-en|ˈ|f|aɪ|t|oʊ|iː|n}}) is a 40-carbon intermediate in the biosynthesis of carotenoids.<ref>{{Cite web |url=http://www.chem.qmul.ac.uk/iubmb/enzyme/reaction/terp/carot.html |title=Carotenoid Biosynthesis |access-date=2009-02-25 |archive-url=https://web.archive.org/web/20161105131635/http://www.chem.qmul.ac.uk/iubmb/enzyme/reaction/terp/carot.html |archive-date=2016-11-05 |url-status=dead }}</ref> The synthesis of phytoene is the first committed step in the synthesis of carotenoids in plants. Phytoene is produced from two molecules of geranylgeranyl pyrophosphate (GGPP) by the action of the enzyme phytoene synthase.<ref>[http://www.curehunter.com/public/keywordSummaryC073128-phytoene-synthase.do Phytoene synthase]</ref> The two GGPP molecules are condensed together followed by removal of diphosphate and proton shift leading to the formation of phytoene.
Dietary phytoene and phytofluene are found in a number of human tissues including the liver, lung, breast, prostate, colon, and skin.<ref>{{Cite journal |last1=Khachik |first1=Frederick |last2=Carvalho |first2=Lorena |last3=Bernstein |first3=Paul S. |last4=Muir |first4=Garth J. |last5=Zhao |first5=Da-You |last6=Katz |first6=Nikita B. |date=November 2002 |title=Chemistry, Distribution, and Metabolism of Tomato Carotenoids and Their Impact on Human Health |url=http://journals.sagepub.com/doi/10.1177/153537020222701002 |journal=Experimental Biology and Medicine |language=en |volume=227 |issue=10 |pages=845–851 |doi=10.1177/153537020222701002 |pmid=12424324 |s2cid=22671223 |issn=1535-3702|url-access=subscription }}</ref> Accumulation of these carotenoids in the skin may protect the skin by several mechanisms: acting as UV absorbers, as antioxidants, and as anti-inflammatory agents.<ref>{{Cite journal| author = Aust, W. Stahl, H. Sies, H. Tronnier, U. Heinrich | title = Supplementation with tomato-based products increases lycopene, phytofluene, and phytoene levels in human serum and protects against UV-light-induced erythema | journal = Int J Vitam Nutr Res | volume = 75 | issue = 1 | pages = 54–60 | year = 2005 | doi = 10.1024/0300-9831.75.1.54 | pmid = 15830922}}</ref><ref>{{Cite journal|author1=B. B. Fuller |author2=D. R. Smith |author3=A. J. Howerton |author4=D. Kern | title = Anti-inflammatory effects of CoQ10 and colorless carotenoids | journal = Journal of Cosmetic Dermatology | volume = 5 | issue = 1 | pages = 30–38 | year = 2006 | doi = 10.1111/j.1473-2165.2006.00220.x | pmid = 17173569|s2cid=9407768 }}</ref>
== Structure ==
Phytoene is a symmetric molecule containing three conjugated double bonds. Phytoene has a UV-Vis absorption spectrum ''typical'' for a triply conjugated system with its main absorption maximum in the UVB range at 286 nm and with ''ε1% of 915''.{{Clarify|date=September 2010}}{{Citation needed|date=September 2010}}
== Sources ==
Analysis of several fruits and vegetables showed that phytoene and phytofluene are found in majority of fruits and vegetables.<ref>{{Cite journal| author = Khachik, F., G.R. Beecher, M.B. Goli, and W.R. Lusby | year = 1991 | title = Separation, identifi cation, and quantification of carotenoids in fruits, vegetables and human plasma by high performance liquid chromatography | journal = Pure Appl. Chem. | volume = 63 | issue = 1 | pages = 71–80 | doi = 10.1351/pac199163010071| s2cid = 36564853 | url = https://zenodo.org/record/1236253 | doi-access = free }}</ref> In contrast to all other carotenoids, phytoene and phytofluene, the first carotenoid precursors in the biosynthetic pathway of other carotenoids, absorb light in the UV range.
==History==
The structure of phytoene was established and proven by total synthesis, by the Basil Weedon group in 1966.<ref>{{cite journal |author1=J. B. Davis |author2=L. M. Jackman |author3=P. T. Siddons |author4=B. C. L. Weedon | title = Carotenoids and related compounds. XV. The structure and synthesis of phytoene, phytofluene, zeta-carotene, and neurosporene | journal = J. Chem. Soc. C | pages = 2154–2165 | year = 1966|doi=10.1039/J39660002154 }}</ref>
==References== {{Reflist}}
==Further reading== *{{cite book |last=Oppen-Bezalel |first=Liki von |last2=Shaish |first2=Aviv |title=The Alga Dunaliella |chapter=Application of the Colorless Carotenoids, Phytoene, and Phytofluene in Cosmetics, Wellness, Nutrition, and Therapeutics |publisher=CRC Press |date=2019-05-07 |orig-year=2009 |isbn=978-0-429-06163-9 |doi=10.1201/9780429061639-18 |oclc=1100588292}}
{{Cholesterol and steroid intermediates}} {{carotenoids}}
Category:Carotenoids Category:Tetraterpenes Category:Substances discovered in the 1960s