3?-(?-D-Glycopyranosyloxy)flavylium Ions: Synthesis and investigation of their properties in aqueous solution. Hydrogen bonding as a mean of colour variation
| Autor: | Olivier Dangles, Hakima El Hajji, Paulo Figueiredo, Raymond Brouillard |
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| Rok vydání: | 1997 |
| Předmět: |
Aqueous solution
Hydrogen bond Chemistry Organic Chemistry Chromophore Biochemistry Catalysis Inorganic Chemistry Pigment chemistry.chemical_compound Chlorogenic acid Computational chemistry visual_art Intramolecular force Drug Discovery visual_art.visual_art_medium Organic chemistry Copigmentation Glycosyl Physical and Theoretical Chemistry |
| Zdroj: | Helvetica Chimica Acta. 80:398-413 |
| ISSN: | 1522-2675 0018-019X |
| DOI: | 10.1002/hlca.19970800206 |
| Popis: | This work describes a straightforward synthesis of two 3’-(,fl-~-glycopyranosyloxy)flavylium ions thought to be good models of natural anthocyanins (pigments). For both pigments and for the non-glycosylated flavylium ion taken as a reference, H,O addition and proton-transfer reactions as well as formation of molecular complexes with chlorogenic acid and caffeine (copigmentation) are quantitatively investigated in mildly acidic aqueous solution. A remarkable affinity of caffeine for the trans-chalcone form of the pigments is demonstrated. Moreover, the differences in the flavylium pK, values are interpreted in terms of possible intramolecular H-bonding between the glycosyl residue and the chromophore. The discussion is then extended to a series of malonylated anthocyanins recently reported for their unusual pigmentation properties. A possible role for the malonyl group (frequently encountered in the structure of naturally occurring anthocyanins) in plant colour expression is outlined for the first time. |
| Databáze: | OpenAIRE |
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