title: Nitrones are able to release nitric oxide in aqueous environment under hydroxyl free radical attack.
abstract: Importance of a nitric oxide donor that can act as a spin trap might bring some new therapeutic possibilities regarding the treatment of ischemic diseases by reducing the intensity of free radical produced reperfusion lesions. These substances might be also used as a new type of photo protectors since they can absorb UV radiation, capture free radicals formed by interaction of UV radiation with tissue constituents, and tanning of the skin will be permitted due to nitric oxide release. The purpose of this work was to measure the ability of nitrones to release nitric oxide and how different factors (temperature, nitrone concentration, and free radicals) influence the releasing ability. Mostly, indirect determination of nitric oxide was carried out, by measuring nitrite and nitrate amounts (as decomposition products of nitric oxide), all nitrones proved to release significant amounts of nitric oxide. Nitrite measurements were made based on an HPLC-VIS method that uses pre-column derivatization of nitrite by forming an azo dye (limit of quantification: 5ng/ml). No good correlation was found between the amount of nitric oxide and temperature for most studied nitrones but between the formation of nitric oxide and nitrone concentration an asymptotic correlation was found. Fenton reagent also yielded formation of nitric oxide from nitrones and formed amounts were not different from those recorded for UV irradiation. Most of the nitrones effectively released about 0.5% of the maximum amount of nitric oxide that is chemically possible and estimated concentrations of 0.1μM were present in the solutions during decomposition.
authors.affiliation: University of Medicine and Farmacy of Târgu Mureş, Nicolae Grigorescu Street, No. 38, Târgu Mureş 540138, Romania. croitorumircea@yahoo.com
authors.forename: Mircea Dumitru
authors.initials: MD
authors.lastname: Croitoru
authors.forename: Fülöp
authors.initials: F
authors.lastname: Ibolya
authors.forename: Maria Cristiana
authors.initials: MC
authors.lastname: Pop
authors.forename: Timea
authors.initials: T
authors.lastname: Dergez
authors.forename: Brânduşa
authors.initials: B
authors.lastname: Mitroi
authors.forename: Maria Titica
authors.initials: MT
authors.lastname: Dogaru
authors.forename: Béla
authors.initials: B
authors.lastname: Tokés
mesh_terms: D017665:Hydroxyl Radical / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000138:chemical synthesis / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry
chemical_list: D009589:Nitrogen Oxides; D012997:Solvents; C015388:nitrones; D014867:Water; D009569:Nitric Oxide; D017665:Hydroxyl Radical