Spectrophotometric Study of Anthocyan Copigmentation Reactions. 2. Malvin and the Nonglycosidized Flavone Quercetin

Using UV−vis spectrophotometry we have established that a process of copigmentation takes place between an anthocyan molecule, malvin chloride (malvidin 3,5-diglucoside), and a nonglycosidized pentahydroxyflavone, quercetin (3,5,7,3‘,4‘-pentahydroxyflavone). The kinetic and thermodynamic parameters, by which the process is characterized, were correlated to the structure, i.e., the nature and position of the substituents in the interacting molecules. Keywords: Copigmentation; quercetin; UV−vis spectra; kinetic and thermodynamic parameters