Structural characterization of new malvidin 3-glucoside-catechin aryl/alkyl-linked pigments

J Agric Food Chem. 2004 Aug 25;52(17):5519-26. doi: 10.1021/jf0494433.

Abstract

The condensation reaction between malvidin 3-glucoside and catechin mediated by isobutyraldehyde, benzaldehyde, and isovaleraldehyde was conducted in model solutions at two pH values (1.5 and 3.2). The formation of new alkyl/aryl-linked adducts corresponding to the structures malvidin 3-glucoside-isobutylcatechin, malvidin 3-glucoside-benzylcatechin, and malvidin 3-glucoside-3-methylbutylcatechin was respectively observed from each aldehyde. The structural characterization of these new structures has been elucidated by 1D and 2D NMR, mass spectrometry, and UV-vis techniques. These new adducts showed the same lambda(max) in the visible region at 540 nm, which is bathochromically shifted 15 nm when compared with the original anthocyanin (lambda(max) = 525 nm).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / chemistry
  • Anthocyanins / chemistry*
  • Benzaldehydes / chemistry
  • Catechin / chemistry*
  • Flavonols / chemistry
  • Glucosides
  • Hydrogen-Ion Concentration
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Pigments, Biological / chemistry*
  • Spectrophotometry, Ultraviolet

Substances

  • Aldehydes
  • Anthocyanins
  • Benzaldehydes
  • Flavonols
  • Glucosides
  • Pigments, Biological
  • isovalerylaldehyde
  • malvidin-3-glucoside
  • Catechin
  • isobutyraldehyde
  • benzaldehyde