Effects of B vitamins on the radiation-induced transformations of hydroxyl-containing organic compounds

In this work, the interaction of B vitamins with α-hydroxyl-containing carbon-centered radicals formed upon the irradiation of deaerated aqueous solutions of ethanol, ethylene glycol, α-methylglycoside, maltose, and α-glycerophosphate at pH 7 was studied by means of continuous radiolysis. Within the framework of the density functional theory, the homolytic bond dissociation enthalpies (BDEs) of -C-H, -O-H, and -N-H bonds and H-atom addition enthalpies (HAEs) at the -C=O and -C=N groups of the test compounds were calculated. The set of the experimental and theoretically calculated data suggests that vitamin B2, nicotinamide and pyridoxal phosphate effectively oxidize α-hydroxyl-containing carbon-centered radicals, whereas vitamins B1 and B6 reduce these radicals to prevent their recombination and fragmentation reactions.