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A free radical resulting from the removal of one hydrogen atom with its electron during the process of dehydrogenation of a hydroquinone to quinone or similar compound (for example, flavin mononucleotide).
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25,26) And the phenolic antioxidants are thought to act via their quinone and semiquinone oxidation products in raising Nrf2.
4benzoqui-none and tetrachloro-1,2-benzoquinone by intermediate steps with formation of respective semiquinone radicals.
Keywords: Elsinochrome A; EPR spectra; Semiquinone anion radical; Autosensitized photooxidation
One electron addition to quinine moiety in the tetracyclic ring of anthracyclines results in the formation of semiquinone and free oxygen radicals such as superoxide anion ([O.
An electron paramagnetic resonance study of the interactions between the adriamycin semiquinone, hydrogen peroxide, iron-chelators, and radical scavengers," Archives of Biochemistry and Biophysics, Vol.
DOX is converted in the cardiac tissue into its semiquinone form, which is a toxic, short-lived metabolite that can interacts with molecular oxygen initiating a cascade of reaction leading to ROS generation (Davies and Doroshow, 1986).
B], the secondary electron acceptor), and the semiquinone [Q.
This semiquinone has been shown to bind to the reductase domain of endothelial nitric oxide synthase (eNOS), resulting in the diversion of electron flow from the oxygenase domain of the enzyme, thus leading to an increase in superoxide generation and reduction in NO production (6).
The data showed a signature typical of free radicals and similar to that of semiquinone, a free radical found in cigarette smoke.
DMBQ then binds to a receptor site on striga and acts as part of a largely uncharacterized redox response circuit in which an electron is transferred through a semiquinone intermediate.
Flavin mononucleotide (FMN), which may be photoreduced under illumination of some tetrapyrrolic compounds to the corresponding semiquinone radical [45], increased slightly the quantum yield of HPD photobleaching (Table 7).