Effects of vitamins, coenzymes and amino acids on reactions of homolytic cleavage of the O-glycoside bond in carbohydrates.

It has been established that vitamins B1, K3 and C, coenzyme Q0 and amino acids cysteine and histidine effectively inhibit reactions of homolytic cleavage of the O-glycoside bond, which are responsible for the destruction of di- and polysaccharides on gamma-irradiation or the action of other reactive radical initiators. This effect was shown to originate from either oxidation or reduction of the radicals of carbohydrates undergoing destruction.

Reactions of alpha-hydroxyethyl radicals with flavonoids of various structures.

It has been found that flavonoids (FL) are able to reduce, add or oxidize alpha-hydroxyethyl radicals (HER). The probability of these processes to occur depends on the structure of the FL under study. Namely, to cause reduction of HER, the presence of hydroxyl groups is necessary, and to effect oxidation or addition of HER, the presence of a carbonyl group at C4 and a C2-C3 double bond in the C ring is required.

Effects of B group vitamins on reactions of various alpha-hydroxyl-containing organic radicals.

Effects of vitamins B1, B2, B6, and pyridoxal phosphate (PPh) on final product formation in radiolysis of aqueous solutions of ethanol, ethylene glycol, alpha-methylglycoside, and maltose were studied. It has been found that vitamin B2 and PPh effectively oxidize R*CHOH species, while suppressing their recombination and fragmentation reactions, thereby increasing the yields of the respective oxidation products. Vitamins B1 and B2 are capable of reducing alcohol radicals to the respective initial molecules, decreasing the yields of the radical transformation products.

Radiation-induced peroxidation and fragmentation of lipids in a model membrane.

Purpose: To ascertain the possibility of fragmentation processes in lipid membranes when acted upon with gamma-radiation under various conditions, and to evaluate fragmentation processes quantitatively in comparison with the lipid peroxidation processes.

Materials And Methods: Phospholipids as components of multilamellar liposomes exposed to 137Cs gamma-rays at dose-rates of 0.06 and 0.