Cyanidin is a natural

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

. It is a particular type of

anthocyanidin Anthocyanidins are common plant pigments, the aglycones of anthocyanins. They are based on the flavylium cation, an oxonium ion, with various groups substituent, substituted for its hydrogen atoms. They generally change color from red through p ...

(

glycoside In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...

version called

anthocyanin Anthocyanins (), also called anthocyans, are solubility, water-soluble vacuole, vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart named a chemical compou ...

s). It is a pigment found in many red berries including

grapes A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus ''Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters. The cultivation of grapes began approximately 8,0 ...

bilberry Bilberries () are Eurasian low-growing shrubs in the genus ''Vaccinium'' in the flowering plant family Ericaceae that bear edible, dark blue berries. They resemble but are distinct from North American blueberries. The species most often referre ...

blackberry BlackBerry is a discontinued brand of handheld devices and related mobile services, originally developed and maintained by the Canadian company Research In Motion (RIM, later known as BlackBerry Limited) until 2016. The first BlackBerry device ...

blueberry Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section ''Cyanococcus'' with the genus ''Vaccinium''. Commercial blueberries—both wild (lowbush) ...

cherry A cherry is the fruit of many plants of the genus ''Prunus'', and is a fleshy drupe (stone fruit). Commercial cherries are obtained from cultivars of several species, such as the sweet '' Prunus avium'' and the sour '' Prunus cerasus''. The na ...

, chokeberry,

cranberry Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus ''Oxycoccus'' of the genus ''Vaccinium''. Cranberries are low, creeping shrubs or vines up to long and in height; they have slender stems that are not th ...

elderberry ''Sambucus'' is a genus of between 20 and 30 species of flowering plants in the family Adoxaceae. The various species are commonly referred to as elder, with the flowers as elderflower, and the fruit as elderberry. Description Elders are most ...

, hawthorn,

loganberry The loganberry (''Rubus'' × ''loganobaccus'') is a hybrid of the North American blackberry ('' Rubus ursinus'') and the European raspberry (''Rubus idaeus''), accidentally bred in 1881 by James Harvey Logan, for whom they are named. They are ...

, açai berry and

raspberry The raspberry is the edible fruit of several plant species in the genus ''Rubus'' of the Rosaceae, rose family, most of which are in the subgenus ''Rubus#Modern classification, Idaeobatus''. The name also applies to these plants themselves. Ras ...

. It can also be found in other fruits such as

apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

s and

plum A plum is a fruit of some species in Prunus subg. Prunus, ''Prunus'' subg. ''Prunus'.'' Dried plums are often called prunes, though in the United States they may be labeled as 'dried plums', especially during the 21st century. Plums are ...

s, and in

red cabbage The red cabbage (purple-leaved varieties of ''Brassica oleracea'' Capitata Cultivar group, Group) is a kind of cabbage, also known as Blaukraut after preparation. Its leaves are coloured dark red/purple. However, the plant changes its co ...

and

red onion Red onions (also known as purple or blue onions in some mainland European countries) are cultivars of the onion ('' Allium cepa''), and have purplish-red skin and white flesh tinged with red. They are most commonly used in cooking, but the skin ...

. It has a characteristic reddish-purple color, though this can change with pH; solutions of the compound are red at pH < 3, violet at pH 7-8, and blue at pH > 11. In certain fruits, the highest concentrations of cyanidin are found in the seeds and skin. Cyanidin has been found to be a potent sirtuin 6 (SIRT6) activator.

List of cyanidin derivatives

Antirrhinin Antirrhinin is an anthocyanin. It is the 3-rutinoside of cyanidin. Occurrence It can be found in ''Antirrhinum majus'' (common snapdragon). It can be found in blackcurrant, açaí, black raspberry, litchi pericarp and common fig The fi ...

(cyanidin-3-

rutinoside Rutinose is the disaccharide also known as 6-''O''-α-L- rhamnosyl-D-glucose (C12H22O10) that is present in some flavonoid glycosides. It is prepared from rutin by hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of wat ...

or 3-C-R), found in

black raspberry Black raspberry is a common name for three species of the genus ''Rubus'': *''Rubus leucodermis'', native to western North America *''Rubus occidentalis ''Rubus occidentalis'' is a species of ''Rubus'' native to eastern North America. I ...

* Cyanidin-3-xylosylrutinoside, found in

* Cyanidin-3,4′-di-''O''-β-glucopyranoside, found in

* Cyanidin-4′-''O''-β-glucoside, found in red onion *

Chrysanthemin Chrysanthemin is an anthocyanin. It is the 3-glucoside of cyanidin (kuromanin). Natural occurrences Chrysanthemin can be found in the roselle plant (''Hibiscus sabdariffa'', Malvaceae), different Japanese angiosperms, '' Rhaponticum'' (Asterac ...

(cyanidin-3-''O''-glucoside), found in

blackcurrant The blackcurrant (''Ribes nigrum''), also known as black currant or cassis, is a deciduous shrub in the family Grossulariaceae grown for its edible berries. It is native to temperate parts of central and northern Europe and northern Asia, w ...

pomace *

Ideain Ideain, the cyanidin 3-O-galactoside, is an anthocyanin, a type of plant pigment. Natural occurrences Ideain is the main anthocyanin in red-skinned or red-fleshed (for example Weirouge) apple varieties. It is also found in Chinese hawthorn frui ...

(cyanidin 3-O-galactoside), found in ''Vaccinium'' species * Cyanin (

cyanidin-3,5-O-diglucoside Cyanidin-3,5-''O''-diglucoside, also known as cyanin, is an anthocyanin. It is the 3,5-''O''-diglucoside of cyanidin. Natural occurrences Cyanin can be found in species of the genus '' Rhaponticum'' (Asteraceae). In food Cyanin can be found ...

), found in

red wine Red wine is a type of wine made from dark-colored grape varieties - (red grapes.) The color of the wine can range from intense violet, typical of young wines, through to brick red for mature wines and brown for older red wines. The juice fro ...

Biosynthesis

Cyanidin can be synthesized in berry plants through the

shikimate pathway The shikimate pathway (shikimic acid pathway) is a seven-step metabolic pathway used by bacteria, archaea, fungi, algae, some protozoans, and plants for the biosynthesis of folates and aromatic amino acids (tryptophan, phenylalanine, and tyrosine) ...

and

polyketide synthase Polyketide synthases (PKSs) are a family of multi- domain enzymes or enzyme complexes that produce polyketides, a large class of secondary metabolites, in bacteria, fungi, plants, and a few animal lineages. The biosyntheses of polyketides share ...

(PKS) III. The shikimate pathway is a biosynthetic pathways that uses the starting materials Phosphoenolpyruvic acid (PEP) and

Erythrose 4-phosphate Erythrose 4-phosphate is a phosphate of the simple sugar erythrose. It is an intermediate in the pentose phosphate pathway and the Calvin cycle. The enzyme transaldolase catalyzes the formation of erythrose 4-phosphate and fructose 6-phosphate ...

to form

shikimic acid Shikimic acid, more commonly known as its anionic form shikimate, is a cyclohexene, a cyclitol and a cyclohexanecarboxylic acid. It is an important biochemical metabolite in plants and microorganisms. Its name comes from the Japanese flower ''shik ...

, which then further reacts to form specific aromatic amino acids. L-

phenylalanine Phenylalanine (symbol Phe or F) is an essential α-amino acid with the chemical formula, formula . It can be viewed as a benzyl group substituent, substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of ...

, 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 The Claisen rearrangement is a powerful carbon–carbon chemical bond, bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl Vinyl group, vinyl ether will initiate a Sigmatropic reaction, ,3sigmatropic r ...

by a Chorismate mutase enzyme to form prephenate. Prephenate undergoes dehydration, decarboxylation, and transamination with

Pyridoxal phosphate Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependen ...

(PLP) and alpha-Ketoglutaric acid to form L-phenylalanine (figure 1). Shikimate Pathway

L-phenylalanine then undergoes an elimination of the primary amine with

Phenylalanine ammonia-lyase The enzyme phenylalanine ammonia lyase (EC 4.3.1.24) catalysis, catalyzes the conversion of L-phenylalanine to ammonia and cinnamic acid, ''trans''-cinnamic acid.: :L-phenylalanine = ''trans''-cinnamate + NH3 Phenylalanine ammonia lyase (PAL) i ...

(PAL) to form cinnamate. Through an oxidation with molecular oxygen and

NADPH Nicotinamide adenine dinucleotide phosphate, abbreviated NADP or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require N ...

, a hydroxyl group is added to the para position of the aromatic ring. The compound then reacts with

Coenzyme A Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the Fatty acid metabolism#Synthesis, synthesis and Fatty acid metabolism#.CE.B2-Oxidation, oxidation of fatty acids, and the oxidation of pyruvic acid, pyruvate in the citric ac ...

(CoA), CoA ligase, and ATP to attach CoA to the carboxylic acid group. The compound reacts with

naringenin Naringenin is a flavanone from the flavonoid group of polyphenols. It is commonly found in citrus fruits, especially as the predominant flavonone in grapefruit. The fate and biological functions of naringenin in vivo are unknown, remaining und ...

chalcone Chalcone is the organic compound C6H5C(O)CH=CHC6H5. It is an α,β-unsaturated ketone. A variety of important biological compounds are known collectively as chalcones or chalconoids. They are widely known bioactive substances, fluorescent materi ...

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

(figure 2). Naringenin synthesis

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 Leucopelargonidin is a colorless chemical compound related to leucoanthocyanins. It can be found in ''Albizia lebbeck'' (East Indian walnut), in the fruit of ''Anacardium occidentale'' (Cashew), in the fruit of ''Areca catechu'' (Areca nut), in th ...

, 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). Cyanidin synthesis

Activation

Among many

s studied, cyanidin most potently stimulated activity of the sirtuin 6 enzyme.

References

{{Anthocyanidins Anthocyanidins