{{Chembox | ImageFile = NJ 2.svg | ImageSize = 250px | ImageAlt = Structure of compound NJ2, a xanthylium pigment found in wine. | IUPACName = 6,20-bis(3,4-dihydroxyphenyl)-7,10,16,19-tetrahydroxy-5,21-dioxa-13-oxoniapentacyclo[12.8.0.0<sup>3,12</sup>.0<sup>4,9</sup>.0<sup>17,22</sup>]docosa-1,3(12),4(9),10,13,15,17(22)-heptaene-2-carboxylic acid | OtherNames = |Section1={{Chembox Identifiers | CASNo = | PubChem = 73194534 | SMILES = Oc6ccc(cc6O)C7Oc(c5CC7O)c4c(C(=O)O)c(c(cc1O)[o+]c4cc5O)c(c1CC2O)OC2c(cc3O)ccc3O | StdInChI=1S/C32H24O13/c33-15-3-1-11(5-19(15)37)28-21(39)7-13-17(35)9-23-25(30(13)44-28)27(32(41)42)26-24(43-23)10-18(36)14-8-22(40)29(45-31(14)26)12-2-4-16(34)20(38)6-12/h1-6,9-10,21-22,28-29,39-40H,7-8H2,(H6-,33,34,35,36,37,38,41,42)/p+1 | StdInChIKey = VVMHZAVGHYVZHM-UHFFFAOYSA-O }} |Section2={{Chembox Properties | C=32 | H=25 | O=13 | Formula_Charge = + | Appearance = | Density = | MeltingPt = | BoilingPt = | Solubility = }} |Section3={{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} }}
'''Compound NJ2''' is a xanthylium yellowish pigment found in wine.
In model solutions, colorless compounds, such as catechin, can give rise to new types of pigments. The first step is the formation of colorless dimeric compounds consisting of two flavanol units linked by carboxy-methine bridge. This is followed by the formation of xanthylium salt yellowish pigments and their ethyl esters, resulting from the dehydration of the colorless dimers, followed by an oxidation process. The loss of a water molecule takes place between two A ring hydroxyl groups of the colorless dimers.<ref>{{cite journal | doi = 10.1046/j.1365-2621.2000.00339.x | title = Xanthylium salts formation involved in wine colour changes | date = 2000 | last1 = Es-Safi | first1 = Nour-Eddine | last2 = Le Guernevé | first2 = Christine | last3 = Fulcrand | first3 = Hélène | last4 = Cheynier | first4 = Véronique | last5 = Moutounet | first5 = Michel | journal = International Journal of Food Science & Technology | volume = 35 | pages = 63–74 }}</ref>
== See also == * Wine color * Phenolic content in wine
== References == {{reflist}}
Category:Polyphenols Category:Heterocyclic compounds with 5 rings Category:Carboxylic acids Category:Oxonium compounds Category:Catechols
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