five new 1-hydroxy-2-(1-alkyloxymethyl)-9,10-anthraquinones (9a-e) have been prepared. selective nitration of 2-methyl-9,10-anthraquinone, reduction to the corresponding amine, diazotization and treatment by sulfuric acid solution afforded the 1-hydroxy-2-methyl-9,10-anthraquinone in good yield as the key intermediate. reaction with dimethylsulphate/k2co3 and subsequent monobromination with nbs...

BACKGROUND Peroxynitrite, a product of the reaction of superoxide with nitric oxide, causes oxidative stress with concomitant inactivation of enzymes, poly(ADP-ribosylation), mitochondrial dysfunction and impaired stress signalling, as well as protein nitration. In this study, we sought to determine the effect of preventing protein nitration or increasing peroxynitrite decomposition on diabetic...

Carbon dioxide interacts both with reactive nitrogen species and reactive oxygen species. In the presence of superoxide, NO reacts to form peroxynitrite that reacts with CO2 to give nitrosoperoxycarbonate. This compound rearranges to nitrocarbonate which is prone to further reactions. In an aqueous environment, the most probable reaction is hydrolysis producing carbonate and nitrate. Thus the n...

nitration of phenol and various 4-substituted phenols with cu(no3)2.3h2o, cu(no3)2.3h2o/sio2, 9h2o and cr(no3)2. 9h2o in different anhydrous organic solvents are investigated. high selectivity ratio of para vs ortho isomers has been observed. mono- and dinitro compounds from phenol and 4-substituted phenols by choosing the proper solvents and reaction conditions, are also obtained with high sel...

Repressor protein modified with N-ethylmaleimide has been used to determine the exclusive effects of tyrosine nitration by tetranitromethane. Since modification of proteins with tetranitromethane generally results in both cysteine oxidation and tyrosine nitration, N-ethylmaleimide has been used to protect the cysteines in the repressor against oxidation in subsequent tetranitromethane reactions...

Despite the therapeutic potential of tempol (4-hydroxy-2,2,6,6-tetra-methyl-1-piperidinyloxy) and related nitroxides as antioxidants, their effects on peroxidase-mediated protein tyrosine nitration remain unexplored. This posttranslational protein modification is a biomarker of nitric oxide-derived oxidants, and, relevantly, it parallels tissue injury in animal models of inflammation and is att...

Tissues are exposed to exogenous and endogenous nitrogen dioxide ((·)NO(2)), which is the terminal agent in protein tyrosine nitration. Besides iron chelation, the hydroxamic acid (HA) desferrioxamine (DFO) shows multiple functionalities including nitration inhibition. To investigate mechanisms whereby DFO affects 3-nitrotyrosine (3-NT) formation, we utilized gas-phase (·)NO(2) exposures, to li...

Tyrosine hydroxylase (TH) is the initial and rate-limiting enzyme in the biosynthesis of dopamine (DA). TH activity is significantly diminished in Parkinson's disease (PD) and by the neurotoxic amphetamines, thereby accentuating the reductions in DA associated with these conditions. Reactive oxygen and nitrogen species have been implicated in the damage to DA neurons seen in PD and in reaction ...

The nitration process of salicylic acid for the production of the important intermediate 5-nitrosalicylic acid is studied from thermokinetic and safety points of view. Investigations carried out by considering, as process deviations, the loss of the thermal control point out the possibility of runaway phenomena due to the occurrence of polynitration reactions. Isothermal experiments are carried...

Nimesulide, a COX-2 selective drug, possesses anti-inflammatory and analgesic properties. Moreover, it has low gastrointestinal and renal toxicity. This paper presents industrially viable, new and improved synthesis of nimesulide starting from o-chloro nitrobenzene. The reaction with triphenyl phosphate yields 2-phenoxy nitrobenzene (90%) followed by reduction and mesylation and finally selecti...