ascorbic-acid and reductone

The antiradical activity of coumarine reductones was investigated by the method of inhibition of Fe2+ induced chemiluminescence of egg-yolk lipoproteins. All coumarines studied exhibited high antioxidant activity. The dependence of chemiluminescence intensity on the antioxidant concentration shows that coumarines reductions resemble their chemical analog--ascorbic acid rather than the lipid antioxidant butilated hydroxitoluene (ionol).

Topics: Ascorbic Acid; Butylated Hydroxytoluene; Coumarins; Depression, Chemical; Dose-Response Relationship, Drug; Egg Proteins; Free Radicals; Lipid Peroxidation; Lipoproteins; Luminescent Measurements; Malondialdehyde; Structure-Activity Relationship

The effect of some reductones such as ascorbic acid (AsA), triose reductone (TR), epinephrine (Ep) and their derivatives on cyclic 3', 5'-adenosine monophosphate phosphodiesterase (cAMP PDE) was studied in the presence or absence of Cu2+. AsA, TR, Ep and the reductones related to them inhibited cAMP PDE activity. Among the reductones, TR showed the highest inhibition. AsA, 5-methyl-3,4-dihydroxytetrone, pyrocatechol, p-hydroxyquinone and resorcinol had a relatively high inhibiting activity. The type of inhibition of AsA, TR and Ep was uncompetitive, competitive and noncompetitive, respectively. Cu2+ enhanced the inhibitory action of the reductones markedly and altered the type of inhibition of the reductones.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Animals; Ascorbic Acid; Cations, Divalent; Cattle; Chloromercuribenzoates; Copper; Epinephrine; Kinetics; Malonates; Malondialdehyde; Myocardium; p-Chloromercuribenzoic Acid; Structure-Activity Relationship

Lambda DNA-fragmenting actions of ascorbic acid (AsA) and triose reductone (TR) in the presence of Cu2+ were studied. The mixture of AsA or TR and Cu2+ caused a marked fragmentation of lambda DNA (3.2 X 10(7) daltons) within the first 1 min of reaction. Further incubation resulted in accumulation of the most abundant species of fragmented lambda DNA having a molecular weight of 1.3 X 10(5) daltons. The mixture of AsA or TR and Cu2+ fragmented calf thymus DNA to produce the fragmented DNA of which 5'-OH terminal groups have a mixture of free OH groups and phosphodiester linkage. The mixture of AsA or TR and Cu2+ was also found to fragment lambda DNA to produce dCMP predominantly as 5'-OH terminal nucleotides.

Topics: Adenosine Triphosphate; Alkaline Phosphatase; Ascorbic Acid; Bacteriophage lambda; Base Composition; Copper; DNA, Viral; Electrophoresis, Agar Gel; Malonates; Malondialdehyde; Molecular Weight; Nucleotides

The mode of DNA-breaking actions of ascorbic acid (AsA) and triose reductone (TR) in the presence of Cu2+ was studied by use of 0.8% agarose slab gel electrophoretic analysis. The DNA-breaking actions of the mixture of AsA or TR and Cu2+ were inhibited by N2 gas, hydroxyl radical scavengers and catalase, indicating that the oxidation of AsA or TR by Cu2+ and the hydrogen peroxide and hydroxyl radicals resulting from the oxidation are essential for the fragmentation of DNA by the mixture of AsA or TR and Cu2+. However, the DNA-breaking activity of these reductones varied with pH, while their oxidation rates were proportional to the increase in pH. The marked fragmentation of DNA occurred at pH 4, 7 or 8. The breakages of DNA by AsA or TR in the presence of Cu2+ were concluded not to be associated with the oxidation rates of reductones.

Topics: Animals; Ascorbic Acid; Cattle; Chemical Phenomena; Chemistry; Copper; DNA; Electrophoresis, Agar Gel; Free Radicals; Hydrogen-Ion Concentration; Kinetics; Malonates; Malondialdehyde; Oxidation-Reduction; Thymus Gland

The role of Cu2+ on the DNA-breaking action of ascorbic acid (AsA) and triose reductone (TR) was studied with an agarose slab gel electrophoretic analysis. AsA and TR decomposed calf thymus DNA which had been pretreated with Cu2+, and their decomposing activity was proportional to the concentration of Cu2+ bound to the DNA. The DNA-Cu2+ complex had the ability to oxidize reductones. AsA and TR also decomposed the pretreated DNA with Cu2+ more markedly than that pretreated with Cu2+ and successively with EDTA. The DNA-breaking activity of AsA and TR showed no Cu2+-concentration dependency. The maximal fragmentation of DNA occurred at the concentration ratio of DNA and Cu2+ of 4:1. Excess concentration of Cu2+ decreased the activity of reductones. The present results indicate that the binding of Cu2+ to DNA molecules is also essential for the DNA-breaking action of AsA and TR in the presence of Cu2+ and that Cu2+ bound to DNA molecules has more effective promoting activity than free Cu2+.

Topics: Animals; Ascorbic Acid; Cattle; Chemical Phenomena; Chemistry; Copper; DNA; Electrophoresis, Agar Gel; Free Radicals; Malonates; Malondialdehyde; Osmolar Concentration; Oxidation-Reduction; Thymus Gland

Topics: Antioxidants; Ascorbic Acid; Cycloparaffins; Hexoses; Malondialdehyde