Influence of trans-cis isomerisation of coumaric acid substituents on colour variance and stabilisation in anthocyanins.
The recently isolated pigments from Petunia integrifolia and Triteleia bridgesii present a distinct feature that sheds new light on the understanding of intramolecular copigmentation of anthocyanins. These are among the infrequent anthocyanins that naturally present a coumaric acid substituent in both cis and trans forms. As a consequence, the two isomers demonstrate substantial variations of their thermodynamic and kinetic constants and also colour properties. A possible explanation for these characteristics is presented, making use of molecular modelling and taking into account the three-dimensional structures of the pigments.
George
F
F
Laboratoire de Chimie des Polyphénols, UMR 7509 du CNRS, Université Louis Pasteur, Faculté de Chimie, 1, rue Blaise Pascal, 67008 Strasbourg, France.
Figueiredo
P
P
Toki
K
K
Tatsuzawa
F
F
Saito
N
N
Brouillard
R
R
D000872:Anthocyanins / Q000737:chemistry*; D003373:Coumaric Acids / Q000737:chemistry*; D007536:Isomerism; D007700:Kinetics; D008958:Models, Molecular; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
D000872:Anthocyanins; D003373:Coumaric Acids