Spin-trapping free radicals in the autooxidation of 6-hydroxydopamine

Author(s): Floyd RA, Wiseman BB


Utilizing the spin-trap 5,5-dimethyl-1-pyrroline-N-oxide, and we h ave demonstrated that hydroxyl free radicals are produced during the alkaline (pH 11.5) autooxidation of 6-hydroxydopamine. The amount of trapped hydroxyl free radical is essentially a linear function of the initial 6-hydroxydopamine concentration up to 2 mM. The iron chelators, diethylenetriamine pentaacetic acid and deferoxamine, considerably reduced the amount of trapped hydroxyl free radical. Catalase and superoxide dismutase were also effective in reducing the amount of hydroxyl free radical spin trapped. Oxygen was absolutely essential for autooxidation of 6-hydroxydopamine and also for formation of the hydroxyl free radical. The semiquinone free radical of 6-hydroxydopamine was present to a small extent in the absence of oxygen. Deferoxamine was effective in lowering the amount of semiquinone radical formed anaerobically, thus suggesting iron was in part responsible for oxidation of 6-hydroxydopamine. The semiquinone free radical yielded an electron spin resonance spectrum characterized by the free electron coupling to four protons having the following coupling constants: H1 ≈ H2 = 2.95 gauss, H3 ≈ 1.1 gauss and H4 ≈ 0.6 gauss.

Similar Articles

Ten misconceptions about antioxidants

Author(s): Bast A, Haenen GR

Cellular stress responses, hormetic phytochemicals and vitagenes in aging and longevity

Author(s): Calabrese V, Cornelius C, Dinkova-Kostova AT, Iavicoli I, Di Paola R, et al.

Shifting from the single to the multitarget paradigm in drug discovery

Author(s): Medina-Franco JL, Giulianotti MA, Welmaker GS, Houghten RA

Amaranth: A Pseudo-cereal with nutraceutical properties

Author(s): Huerta-Ocampo JA, Barba de la Rosa AP

Peculiarities of amaranth oil influence on the liver antioxidant system and blood of mice with tumor growth

Author(s): Yelisyeyeva OP, Kamisnkyy DV, Cherkas AP, Ambarova LI, Vyshemyrska OR, et al.

The effect of Amaranth oil on monolayers of artificial lipids and hepatocyte plasma membranes with adrenalin-induced stress

Author(s): Yelisyeyeva OP, Semen KO, Ostrovska GV, Kaminskyy DV, Sirota TV, et al.

Effect of amaranth seeds in diet on oxidative status in plasma and selected tissues of high fructose-fed rats

Author(s): Pasko P, Bartn H, Zagrodizki P, Chlopicka J, Izewska A, et al.

Amaranth oil application for coronary heart disease and hypertension

Author(s): Martirosyan DM, Miroshnichenko LA, Kulakova SN, Pogojeva AV, Zoloedov VI

Nutrilipidomics: a tool for personalized health J

Author(s): Chatgilialoglu C, Ferreri C

Fatty acid profile of erythrocyte membranes as possible biomarker of longevity

Author(s): Puca AA, Andrew P, Novelli V, Anselmi CV, Somalvico F, et al.

Oxidative stress and antioxidants in interstitial lung disease

Author(s): Bast A, Weseler AR, Haenen GR, den Hartog GJ