title: Copigmentation of malvidin-3-O-glucoside with five hydroxybenzoic acids in red wine model solutions: experimental and theoretical investigations.
abstract: In the present research, the copigmentations of malvidin-3-O-glucoside with five hydroxybenzoic cofactors (p-hydroxybenzoic acid, protocatechuic acid, gallic acid, vanillic acid, and syringic acid) were investigated. The influence of the concentration of these cofactors and the reaction temperature was examined. The equilibrium constant (K), stoichiometric ratio (n) and the thermodynamic parameters (ΔG°, ΔH°, ΔS°) related to the copigmentation were also reported here. Theoretical calculations were performed to identify the relative arrangement between the pigment and cofactors in the copigmentation complexes. Besides, the comparison of the relative binding free energies (ΔΔGbinding) derived from the theoretical calculations and experimental data were made, and the binding strength of these copigmentation complexes was discussed with the interaction energies (ΔE). AIM analysis was also used to explore the main driving forces contributing to the copigmentation. In the comparison of the five studied cofactors, syringic acid had a stronger copigmentation effect than the other four phenolic acids investigated.
authors.affiliation: Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Fei
authors.initials: F
authors.lastname: He
authors.affiliation: College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
authors.forename: Pan-Pan
authors.initials: PP
authors.lastname: Zhou
authors.affiliation: Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: chqduan@cau.edu.cn.
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Duan
mesh_terms: D000872:Anthocyanins / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000032:analysis* / Q000737:chemistry; D013816:Thermodynamics; D014920:Wine / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D005960:Glucosides; D062385:Hydroxybenzoates; C458419:malvidin-3-glucoside; C017616:phenolic acid
keywords: Anthocyanin; Copigmentation; Hydroxybenzoic acid; Theoretical calculations; Thermodynamic parameters