- Thermodynamics and kinetics of cyanidin 3-glucoside and caffeine copigments
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The multiequilibrium system of reactions of cyanidin 3-glucoside at acidic and mildly acidic pH values was studied in the presence of caffeine as a copigment. The thermodynamic and kinetic constants were determined using the so-called direct and reverse pH jump experiments that were followed by conventional UV-vis spectroscopy or stopped flow coupled to a UV-vis detector, depending on the rate of the monitored process. Compared with that of free anthocyanin, the copigmentation with caffeine extends the domain of the flavylium cation up to less acidic pH values, while in a moderately acidic medium, the quinoidal base becomes more stabilized. As a consequence, the hydration to give the colorless hemiketal is difficult over the entire range of pH values. At pH 1, two adducts were found for the flavylium cation-caffeine interaction, with stoichiometries of 1:1 and 1:2 and association constants of 161 M-1 (K1) and 21 M-1 (K2), respectively.
- Limon, Piedad M.,Gavara, Raquel,Pina, Fernando
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p. 5245 - 5251
(2013/07/27)
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- COMPOSITIONS INCLUDING ANTHOCYANIN OR ANTHOCYANIDIN FOR THE PREVENTION OR TREATMENT OF ARTICULAR CARTILAGE-ASSOCIATED CONDITIONS
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Methods of treating an arthritic joint of a subject, including administering a pharmaceutical composition by injection into the arthritic joint, wherein the composition includes an anthocyanin or anthocyanidin, glucose, and a pharmaceutically acceptable carrier.
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- METHOD FOR THE SYNTHESIS OF ANTHOCYANINS
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The present invention relates to methods of preparing anthocyanins, and methods of preparing precursors of anthocyanins. The methods utilise a coupling reaction between a sugar and a suitable electrophilic precursor to form Eastern half intermediates, that are then reacted with Western half intermediates to form the target anthocyanins. Some Eastern half intermediates and electrophilic precursors also form part of the invention.
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Page/Page column 17; 25-26
(2008/06/13)
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