Anthocyanins
From WikiLectures
- Basic structure
- Pelargonidin Pg... R1 = H, R2 = H violet-red
- Cyanidin Cy... R1 = H, R2 = OH purple
- Delfinidin Dp... R1 = OH, R2 = OH blue-violet
- Peonidin Pn... R1 = H, R2 = OCH3 violet
- Petunidin Pt... R1 = OH, R2 = OCH3 dark red
- Malvidin Mv... R1 = OCH3, R2 = OCH3 blue-violet
- Carbohydrates: Glu, Gal, Xyl, Ara, Rha, always C-3, often C-3 and C-5, rarely C-7
- Acids: p-coumaric, caffeic, ferulic
Examples:
- Cyanidin-3-O-β-D-glucoside (generally known)
- (E)-petunidin-3-O-[6-O-(4-O-p-kumaroyl-α-L-rhamnopyranosyl)-β-D-glukopyranosid]-5-O-β-D-glukopyranosid
- Trivially: petanin (red potato variety)
Anthocyanins of fruits and vegetables
- Dependence of coloration on various factors:
- pH of the environment;
- Copigmentation, or transformation to other dyes;
- sulphur dioxide;
- hydrogen peroxide
pH of the medium
- Copigmentation
- Interaction with procyanidins (e.g. catechins, so-called copigments) → colour complex.
- Transformation to other dyes, colour complex → dimer (oligomer), insoluble condensation products, sediments phlobaphenes.
- Sulphur dioxide → colourless sulphonic acids.
- Hydrogen peroxide → colourless products.
Links[edit | edit source]
Internal links[edit | edit source]
References[edit | edit source]
- DAVÍDEK, Jiří. 11. SLOUČENINY OVLIVŇUJÍCÍ BARVU POTRAVIN [online]. [cit. 2012-03-13]. <https://el.lf1.cuni.cz/p21372106/>.
