The electron spin resonance (EPR) spin-trapping technique allows detection of radical species with nanosecond half-lives. This technique is based on the high rates of addition of radicals to nitrones or nitroso compounds (spin traps; STs). The paramagnetic nitroxides (spin-adducts) formed as a result of reactions between STs and radical species are relatively stable compounds whose EPR spectra ...

Enzyme-catalyzed signal amplification was introduced to the electrochemical detection of the OH radical. In the presence of phenol as a trapping agent, glucose as a substrate, and pyrroloquinoline quinone-containing glucose dehydrogenase (PQQ-GDH) as a catalyst, the current signal for the trapping adducts (catechol and hydroquinone) produced by the hydroxylation of phenol could be amplified an...

acterizing free radicals in chemistry, biology and medicine, is detection by EPR spectroscopy. However, due to their high reactivity and short half-lives, direct EPR detection of many free radicals (e.g., superoxide, hydroxyl radical, alkyl radicals, etc.) is virtually impossible in solution at room temperature. Spin trapping is a technique developed in the late 1960s in which a nitrone or nitr...

The oxidative metabolism of hydralazine, isoniazid, iproniazid, and phenylhydrazine has been studied using spin-trapping techniques. The oxidation of these hydrazine derivatives, catalyzed by horseradish peroxidase and prostaglandin synthetase, produces reactive free radical intermediates. Enzymatic activation of hydralazine produce the nitrogen-centered hydralazyl radical (RNHNH.); phenylhydra...

[structure: see text] Pyridoxamine is known to be an effective inhibitor of both advanced glycation (AGE) and advanced lipoxidation (ALE) end products. The synthesis of a novel multifunctional AGE and ALE inhibitor, 6-dimethylaminopyridoxamine (dmaPM, 11) is described. The 6-dimethylamino substituent increases the radical trapping ability of pyridoxamine's phenolic group. Results obtained durin...

BACKGROUND Isoferulic acid (IFA), a naturally occurring cinnamic acid derivative, is a main active ingredient of the rhizoma of Cimicifuga dahurica. It has been shown various pharmacological activities. The aim of the study was to investigate the effect of IFA against MG-induced protein glycation and oxidative DNA damage. Free radical scavenging activity and the MGO-trapping abilities of IFA we...

During the past two decades, the ESR spin-trapping technique has been used extensively to detect free radicals generated by metabolism of xenobiotic compounds in vitro. Although this ESR technique has proven useful in vitro, it has only recently been applied to drug metabolism in vivo. Spin trapping has successfully been employed to study the metabolism of halocarbons, hydrazines and hydroperox...

It has been hypothesized that hyperthermia promotes oxygen-centered free radical formation in cells; however, to date there is no direct evidence of this heat-induced increase in oxygen free radical flux. Using electron paramagnetic resonance (EPR) spin trapping, we sought direct evidence for free radical generation during hyperthermia in intact, functioning cells. Rat intestinal epithelial cel...

The antioxidant activity of catechins and oligomeric procyanidins against low density lipoproteins peroxidation was studied by means of three distinct methods: cis-parinaric acid fluorescence decay, conjugated-dienes detection, and oxygen consumption. A relationship between the radical trapping efficiency of procyanidins and their structure was investigated. The results indicated that: (i) inte...