Chemical synthesis of hydroxycinnamic acid glucosides and evaluation of their ability to stabilize natural colors via anthocyanin copigmentation

J Agric Food Chem. 2007 Sep 5;55(18):7573-9. doi: 10.1021/jf071205v. Epub 2007 Aug 8.

Abstract

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.

MeSH terms

  • Anthocyanins / chemistry*
  • Coumaric Acids / chemical synthesis*
  • Coumaric Acids / pharmacology
  • Glucosides / chemical synthesis*
  • Glucosides / chemistry
  • Glucosides / pharmacology
  • Pigmentation / drug effects*

Substances

  • Anthocyanins
  • Coumaric Acids
  • Glucosides
  • malvin