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Malvidin 3-glucoside

Oenin
Malvidin-3-glucoside.svg
Names
IUPAC name
(2S,3R,4S,5S,6R)-2-[5,7-dihydroxy-2-(4-hydroxy-3,5-dimethoxyphenyl)chromenylium-3-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol
Other names
Enin
Malvidin-3-glucoside
Malvidin 3-O-glucoside
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.027.847
PubChem CID
Properties
C23H25O12+, C23H25ClO12 (chloride)
Molar mass 493.43 g/mol, 528.89 g/mol (chloride)
Appearance dark brown powder (chloride)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references

Oenin is an anthocyanin. It is the 3-glucoside of malvidin. It is one of the red pigments found in the skin of purple grapes and in wine.

Color stabilization of malvidin 3-glucoside at a higher pH can be explained by self-aggregation of the flavylium cation and copigmentation with the Z-chalcone form. In the presence of procyanidin C2, the red color of oenin appears more stable. However, the HPLC chromatogram shows a decrease in the amplitude of the peaks of oenin and procyanidin C2. Concomitantly, a new peak appears with a maximal absorption in the red region. This newly formed pigment probably comes from the condensation of oenin and procyanidin C2.

Malvidin 3-glucoside alone is not oxidized in the presence of grape polyphenol oxidase, whereas it is degraded in the presence of a crude grape PPO extract and of caftaric acid forming anthocyanidin-caftaric acid adducts.



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