[A comparative study of the activity of antihypoxic agents in hemic hypoxia]. / Sravnitel'noe izuchenie aktivnosti protivogipoksicheskikh sredstv pri gemicheskoi gipoksii.

Amino derivatives of ortho-benzoquinone (OBQ) were demonstrated to have a protective action in acute toxic hemic hypoxia induced by sodium nitrite given to laboratory animals. This action of OBQ was due to its capacity to activate the recovery of blood oxygen transport function by accelerating the restoration of methemoglobin and determined by their electron-acceptor properties, lipophilicity and NADP-dependent methemoglobin reductase affinity.

4-(4-R-phenylamino)-5-methoxy-1,2-benzoquinones are new selective inhibitors of carbon tetrachloride-initiated free radical reactions in liver.

The action of several 1,2-benzoquinone derivatives on free radical processes initiated by carbon tetrachloride was studied. Among them a substance that effectively inhibited lipid peroxidation without substantial influence on covalent binding of radical products of metabolic cleavage of carbon tetrachloride as well a substance that equally inhibited both processes were found. It was shown that 1,2-benzoquinones can be useful tool for investigation of free radical mechanisms of carbon tetrachloride-initiated liver cell damage in vivo.

[Antioxidative activity of flavonoids in various systems of lipid peroxidation]. / Antiokislitel'naia aktivnost' flavonoidov v razlichnykh sistemakh perekisnogo okisleniia lipidov.

The antioxidant action of flavonols in different systems of lipid peroxidation (LPO) was studied. Quercetin and rutin were found to inhibit NADPH and CCl4-dependent LPO in rat liver microsomes, however, in the case of CCl4-dependent LPO, rutin had a very poor antioxidant effect. Study of flavonols oxidation by products of the cytochrome c catalyzed destruction of linoleic acid hydroperoxide demonstrated that the differences in the antioxidant offects of quercetin and rutin can be due to their different capability to terminate free radical chain reactions. The antioxidant effect of rutin was shown to be largely due to the chelating properties of this compound.