Effects of ascorbic acid (AA), ascorbic acid glycoside (AAG) and alpha-tocopherol monoglycoside (TMG) on radiation - and H(2)O(2)-induced decomposition of thymine in aqueous solutions were investigated. Of the three compounds studied, AAG was found to possess the most marked protector properties. An explanation of this phenomenon has been given in terms of differences in molecular structures of AA and AAG, as well as properties of radical adducts formed during their interaction with OH radicals.

Effects of vitamins B, C, E, K and P, as well as coenzymes Q, on formation of final products of radiation-induced free-radical transformations of ethanol, ethylene glycol, alpha-methylglycoside and glucose in aqueous solutions were studied. Based on the obtained results, it can be concluded that there are substances among vitamins and coenzymes that effectively interact with alpha-hydroxyl-containing radicals. In the presence of these substances, recombination reactions of alpha-hydroxyalkyl radicals and fragmentation of alpha-hydroxy-beta-substituted organic radicals are suppressed. It has been established that the observed effects are due to the ability of the vitamins and coenzymes under study to either oxidize alpha-hydroxyl-containing radicals yielding the respective carbonyl compounds or reduce them into the initial molecules.

The effects of vitamins Ç 1 , Ç 2 , and Ç 6 and pyridoxal phosphate on the formation of the final radiolysis products of aqueous ethanol and ethylene glycol solutions were studied. It was found that vitamin Ç 2 and pyridoxal phosphate effectively oxidize CHOH species to suppress their recombination and fragmentation reactions, thereby increasing the yields of corresponding oxidation products. Vitamins Ç 1 and Ç 6 are capable of reducing alcohol radicals to the parent molecules and, hence, decreasing the yields of the main radiolysis products. R . 278

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