Natural Carboxyl-Containing Phenols and Monosaccharides in Radical Oxidation and Complex Formation Reactions

It was found by the photocolorimetry method that in acidic media, compositions of natural carboxyl-containing phenols (antioxidants) with monosaccharides (synergists) show an antiradical synergistic effect in reactions with 2,2ʹ-diphenyl-1-picrylhydrazyl, the maximum value of which is typical for binary mixtures of sinapic, gentisic, and ferulic acids with galactose and mannose. It was shown by NMR spectroscopy and difference UV spectroscopy methods that the synergism mechanism consists in the formation of intermolecular hydrogen-bonded phenol-monosaccharide complexes in the ratio of 1:1. A combined model for selecting phenolic-saccharide compositions with high synergistic effect was proposed on the basis of quantum chemical DFT and regression analysis methods.