Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively....Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively. It was found thatβ-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.展开更多
Thermokinetics of the dismutation of superoxide anion (O 2 .- ) catalyzed by superoxide dismutase (SOD), in which the decomposition of hydrogen peroxide catalyzed by catalase is utilized as a source of oxygen and the ...Thermokinetics of the dismutation of superoxide anion (O 2 .- ) catalyzed by superoxide dismutase (SOD), in which the decomposition of hydrogen peroxide catalyzed by catalase is utilized as a source of oxygen and the autoxidation of pyrogallod as a source of the substrate (O 2 .- ), has been studied by microcalorimetry. The molar reaction enthalpies of the SOD reaction and the pyrogallol autoxidation have been measured as - 160.1 and - 218 kJ · mol-1, respectively, at 298. 15 K and pH 7.0. A novel method for the determination of SOD activity, the microcalorimetric assay for SOD, has been proposed. The experimental results showed that SOD had no effect on both kinetic parameters and the mechanism for the pyrogallol autoxidation. This autoxidation followed the second-order reaction kinetics in the presence of limited oxygen (the first order with respect to both pyrogallol and O2), and the second-order rate constants were hermined at 298.15 K and pH 8.0 to be 1.25 and 1.30 L·mol-1·s-1 in the absence and presence of SOD, respectively. A possible mechanism for the autoxidation of pyrogallol inhibited by SOD was also suggested.展开更多
文摘Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively. It was found thatβ-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.
文摘Thermokinetics of the dismutation of superoxide anion (O 2 .- ) catalyzed by superoxide dismutase (SOD), in which the decomposition of hydrogen peroxide catalyzed by catalase is utilized as a source of oxygen and the autoxidation of pyrogallod as a source of the substrate (O 2 .- ), has been studied by microcalorimetry. The molar reaction enthalpies of the SOD reaction and the pyrogallol autoxidation have been measured as - 160.1 and - 218 kJ · mol-1, respectively, at 298. 15 K and pH 7.0. A novel method for the determination of SOD activity, the microcalorimetric assay for SOD, has been proposed. The experimental results showed that SOD had no effect on both kinetic parameters and the mechanism for the pyrogallol autoxidation. This autoxidation followed the second-order reaction kinetics in the presence of limited oxygen (the first order with respect to both pyrogallol and O2), and the second-order rate constants were hermined at 298.15 K and pH 8.0 to be 1.25 and 1.30 L·mol-1·s-1 in the absence and presence of SOD, respectively. A possible mechanism for the autoxidation of pyrogallol inhibited by SOD was also suggested.
