ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The synthesis of 3-glycosyloxylated flavylium ions (anthocyanins), in particular of callistephin (4), a natural anthocyanin, is described. The structural transformations in aqueous solution and molecular complexation with chlorogenic acid (7) and caffeine (8) of the synthesized pigments 3 and 4 are investigated and compared to those of the corresponding 3-methoxyflavylium ions 1 and 2 and to those of oenin (5) and malvin (6), two very common natural anthocyanins. The results are discussed in terms of the role played by the glycosyloxy residues in the chemical properties of anthocyanins. Anthocyanin molecular complexation (copigmentaion) is quantitatively investigated by UV/VIS spectroscopy and 1H-NMR. In particular, the UV/VIS spectroscopic data are interpreted using a general theoretical treatment, which, e.g., allows to demonstrate the formation of molecular complexes between the colourless forms of an anthocyanin and 8.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19940770616
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