Reactive oxygen series

Results of a more recent series of investigations suggest that lead may cause hypertension in rats by increasing reactive oxygen species, which act as vasoconstrictors, and decreasing nitric oxide, a vasodilator released by the endothelium. The reactive oxygen species may be the hydroxyl radical, and did not appear to be the superoxide anion (Ding et al. 1998). 

Probably because prenyl derivatives of dihydric phenols are more involved naturally and more reactive than those of the monhydric series as the precursors of many cyclic oxygen ring compounds they have attracted synthetic interest. Although the alkylation of hydroquinones affords good yields, the more reactive resorcinol series do not respond well and isomer formation occurs. Thus, (ref.9), hydroquinone as the disodium salt in hot benzene with 3-methylbuten-2-yl chloride gave 4-hydroxy-2-(3-methylbuten-2-yl)phenol in 66%... 

Once the 0-0 bond is weakened one of the oxygen atoms of O2 molecule can interact with the framework forming the series of defects described above. Such a defect further evolves and the reactive oxygen moves to the adjacent cage where there is still a NOj anion. At this point the atomic oxygen reacts and form a second NO3. This proposed mechanism seems to fit to the first order kinetic with respect to NO3, as described... 

Very recently, Williams et al. suggested that these reactive oxygen species may be harmful to polymeric implant surfaces through their production of highly reactive, potent, and harmful hydroxyl radicals OH in the presence of metals like iron as shown in the foUowing series of redox reactions [Williams et al., 1991 AKetal, 1993 Zhongetal., 1994]. 

Gout usually develops after a number of years of uric acid build-up (4), the final product of a series of chemical process from hypoxanihine (2), which are catalyzed by xanthine oxidase, an enzyme that generates reactive oxygen species. Xanthine (3) can be... 

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