Cyanidin

• Antirrhinin (cyanidin-3-rutinoside or 3-C-R), found in black raspberry{{cite journal | vauthors = Tulio AZ, Reese RN, Wyzgoski FJ, Rinaldi PL, Fu R, Scheerens JC, Miller AR | title = Cyanidin 3-rutinoside and cyanidin 3-xylosylrutinoside as primary phenolic antioxidants in black raspberry | journal = Journal of Agricultural and Food Chemistry | volume = 56 | issue = 6 | pages = 1880–8 | date = March 2008 | pmid = 18290621 | doi = 10.1021/jf072313k | quote = Five anthocyanins were present in black raspberries: cyanidin 3-sambubioside, cyanidin 3-glucoside, cyanidin 3-xylosylrutinoside, cyanidin 3-rutinoside, and pelargonidin 3-rutinoside. Their identities and structures, with particular emphasis on cyanidin 3-xylosylrutinoside, were confirmed by NMR spectroscopy. Two of these anthocyanins, cyanidin 3-rutinoside and cyanidin 3-xylosylrutinoside, predominated, comprising 24-40 and 49-58%, respectively, of the total anthocyanins in black raspberries. On the basis of both potency and concentration, cyanidin 3-rutinoside and cyanidin 3-xylosylrutinoside were found to be the significant contributors to the antioxidant systems of black raspberries. }}
• Cyanidin-3-xylosylrutinoside, found in black raspberry
• Cyanidin-3,4′-di-O-β-glucopyranoside, found in red onion
• Cyanidin-4′-O-β-glucoside, found in red onion
• Chrysanthemin (cyanidin-3-O-glucoside), found in blackcurrant pomace
• Ideain (cyanidin 3-O-galactoside), found in Vaccinium species
• Cyanin (cyanidin-3,5-O-diglucoside), found in red wine{{cite journal | vauthors = He F, Liang NN, Mu L, Pan QH, Wang J, Reeves MJ, Duan CQ | title = Anthocyanins and their variation in red wines I. Monomeric anthocyanins and their color expression | journal = Molecules | volume = 17 | issue = 2 | pages = 1571–601 | date = February 2012 | pmid = 22314380 | pmc = 6268338 | doi = 10.3390/molecules17021571 | doi-access = free }}

Cyanidin can be synthesized in berry plants through the shikimate pathway and polyketide synthase (PKS) III. The shikimate pathway is a biosynthetic pathways that uses the starting materials Phosphoenolpyruvic acid (PEP) and Erythrose 4-phosphate to form shikimic acid, which then further reacts to form specific aromatic amino acids. L-phenylalanine, which is necessary in the production of cyanidin, is synthesized through the shikimate pathway.

In the synthesis of L-phenylalanine, chorismate undergoes a Claisen rearrangement by a Chorismate mutase enzyme to form prephenate. Prephenate undergoes dehydration, decarboxylation, and transamination with Pyridoxal phosphate (PLP) and alpha-Ketoglutaric acid to form L-phenylalanine (figure 1).

File:Shikimate Pathway.png

L-phenylalanine then undergoes an elimination of the primary amine with Phenylalanine ammonia-lyase (PAL) to form cinnamate. Through an oxidation with molecular oxygen and NADPH, a hydroxyl group is added to the para position of the aromatic ring. The compound then reacts with Coenzyme A (CoA), CoA ligase, and ATP to attach CoA to the carboxylic acid group. The compound reacts with naringenin-chalcone synthase and three malonyl CoA molecules to add six carbon atoms and three more keto groups ring through PKS III. Aureusidin synthase catalyses the aromatization and cyclization of the newly added carbonyl groups and facilitates the release of CoA. The compound then spontaneously cyclizes to form naringenin{{cite web |title=Chalcone and Stilbene Biosynthesis |url=http://www.chem.qmul.ac.uk/iubmb/enzyme/reaction/phenol/chalcone.html |publisher=Queen Mary University of London |archive-url=https://web.archive.org/web/20151018000745/http://www.chem.qmul.ac.uk/iubmb/enzyme/reaction/phenol/chalcone.html |archive-date=18 October 2015 |url-status=dead}} (figure 2).

File:Naringenin synthesis.png

Naringenin is then converted to cyanidin through several oxidizing and reducing steps. First naringenin is reacted with two equivalents of oxygen, alpha-Ketogluteratic acid, and flavanone 3-hydroxylase to form dihydrokaempferol. The compound then reacts with NADPH and dihydroflavonol 4-reductase to form leucopelargonidin, which is further oxidized with oxygen, alpha-Ketogluteratic acid, and anthocyanidin synthase. This compound spontaneously loses a water molecule and a hydroxide ion to form cyanidinDewick, P. M. Medicinal Natural Products: A Biosynthetic Approach, 3rd ed.; John Wiley and Sons, Ltd: United Kingdom 2009; pp 137-186 (figure 3).

File:Cyanidin synthesis.png

Among many anthocyanidins studied, cyanidin most potently stimulated activity of the sirtuin 6 enzyme.{{cite journal | vauthors=Klein MA, Denu JM | title=Biological and catalytic functions of sirtuin 6 as targets for small-molecule modulators | journal=Journal of Biological Chemistry | volume=295 | issue=32 | pages=11021–11041 | year=2020 | url=https://www.jbc.org/content/295/32/11021.long | doi = 10.1074/jbc.REV120.011438| pmc= 7415977 | pmid=32518153| doi-access=free }}

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{{Anthocyanidins}}

Category:Anthocyanidins