Spectrophotometric Study of Anthocyan Copigmentation Reactions. 3. Malvin and the Nonglycosidized Flavone Morin

Abstract

The process of copigmentation between malvin chloride (malvidin 3,5-diglucoside) and morin hydrate (3,5,7,2′4′-pentahydroxyflavone) was studied. The UV-vis absorption spectra were used to define the optimum conditions for the formation of copigment, as well as their characteristics. It was established that the copigmentation process does not depend only on the number of hydroxy groups but also on their mutual position. The copigment formation is spectrally manifested in a bathochromic and hyperchromic shift of the longest wavelength absorption band. The copigment formed is defined by kinetic and thermodynamic parameters.