The Equation 32, shows that since hypochloride radical anion
is less reactive compared to hydroxyl radical hence reaction is evidently obstructed.
In case an amount equivalent to one electron is transferred, the nucleophile becomes a radical cation, while the electrophile becomes a radical anion
. Interestingly, analysis of the atomic spin density (ASD) at the radical cation and the radical anion
gives a picture of the distribution of the electron density in the electrophile and the nucleophile when they approach each other along the reaction progress.
The polyphenol components isolated from the fruiting body of Inonotus obliquus, namely, inonoblins and phelligridins (Figure 3(d)), were also demonstrated to exhibit significant DPPH radical scavenging and moderate superoxide radical anion
scavenging activities .
The proposed mechanism for the cytotoxic effect of ascorbate begins with the donation of an electron from ascorbate to molecular oxygen creating a superoxide radical anion
, followed by conversion to hydrogen peroxide by several mechanisms.
Scavenging of Superoxide Radical Anion
. Figure 5 plots the scavenging activity of superoxide radical anion
barteri root extracts (DMHBR) on different antioxidant models (n = 6 in each group) Scavenging activity of DMHBR (% inhibition) * Concentration ([micro]g/ml) DPPH Nitric oxide Hydroxyl Superoxide radical anion
10 9.89 19.2 14.79 14.44 100 26.7 32.7 41.87 27.94 200 34.92 34.6 49.53 49.66 300 43.79 36.5 57.93 55.47 400 49.49 40.4 66.24 61.4 500 56.58 55.7 74.54 69.37 [IC.sub.50] 397.69 475.88 244.22 285.20 ([micro]g/ml) * Values are expressed as percentage mean of 3 replicates
The formation of sulfur trioxide radical anion
during the prostaglandin hydroperoxidase-catalyzed oxidation of bisulfite (hydrated sulfur dioxide).
Furthermore, EAF treatment decreased the production of superoxide radical anion
by cells isolated from the pleural cavity, while it did not affect the nitrite/nitrate levels in exudates.
"Most of the isotope effect that is observed is inherent to the structure of the radical anion
Quinones can abstract an electron from triplet porphyrins, giving a radical cation of the porphyrin and a radical anion
of the quinone .
Specially, h+VB may react with surface-bound H2O or OH- to produce the hydroxyl radical and e-CB is picked up by oxygen to generate superoxide radical anion
When molecular oxygen introduced in reaction media, it reacts with H* and e-aq to form superoxide radical anion
, O2* - and hydroperoxy radical HO2* Addition of H2O2 not only scavenges the reducing species (H* and e-aq) but also facilitate the oxidation process .