Chemical synthesis of hydroxycinnamic acid glucosides and evaluation of their ability to stabilize natural colors via anthocyanin copigmentation.
This work describes the chemical synthesis of O-aryl-beta-D-glucosides and 1-O-beta-D-glucosyl esters of hydroxycinnamic acids. In particular, O-aryl-beta-D-glucosides were efficiently prepared via a simple diastereoselective glycosylation procedure using phase transfer conditions. Despite the lability of its ester linkage, 1-O-beta-D-caffeoylglucose could also be obtained using a Lewis acid catalyzed glycosylation step and a set of protective groups that can be removed under neutral conditions. Hydroxycinnamic acid O-aryl-beta-D-glucosides were then quantitatively investigated for their affinity for the naturally occurring anthocyanin malvin (pigment). Formation of the pi-stacking molecular complexes (copigmentation) was characterized in terms of binding constants and enthalpy and entropy changes. The glucosyl moiety did not significantly alter these thermodynamic parameters, in line with a binding process solely involving the polyphenolic nuclei.
Galland
Stephanie
S
UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université d'Avignon, 33 rue Louis Pasteur, 84029 Avignon, France.
Mora
Nathalie
N
Abert-Vian
Maryline
M
Rakotomanomana
Njara
N
Dangles
Olivier
O
D000872:Anthocyanins / Q000737:chemistry*; D003373:Coumaric Acids / Q000138:chemical synthesis* / Q000494:pharmacology; D005960:Glucosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010858:Pigmentation / Q000187:drug effects*
D000872:Anthocyanins; D003373:Coumaric Acids; D005960:Glucosides; C502603:malvin