Scavenging of superoxide anion radical and hydroxyl radical by novel thiazolyl‐thiazolidine‐2,4‐dione compounds

Abstract

The antioxidant behavior of a series of new synthesized substituted thiazolyl-thiazolidine-2,4-dione compounds (TZDs) was examined using chemiluminescence and electron paramagnetic resonance spin trapping techniques. 5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) was used as the spin trap. The reactivity of TZDs with superoxide anion radical (O2(*-)) and hydroxyl radical (HO(*)) was evaluated using potassium superoxide/18-crown-6 ether dissolved in dimethylsulfoxide, and the Fenton-like reaction (Fe(2+) + H2O2), respectively. The results showed that TZDs efficiently inhibited light emission from the O2(*-) generating system at a concentration of 0.05-1 mmol L(-1) (5-94% reductions were found at 1 mmol L(-1) concentration). The TZD compounds showed inhibition of HO(*)-dependent DMPO-OH spin adduct formation from DMPO (the amplitude decrease ranged from 8 to 82% at 1 mmol L(-1) concentration). The findings showed that examined TZDs had effective activities as radical scavengers.

Synthesis and activity of a coumarin‐based fluorescent probe for hydroxyl radical detection

“…In this method, 5,5‐dimethyl‐1‐pyrroline Noxide (DMPO) or Tempo is usually used as a spin‐trap (also known as an intermediate) . For example, Aboul‐eneim's group has used DMPO as a spin‐trap to evaluate the ·OH‐scavenging ability of a series of compounds using the EPR technique . Similar to the first strategy of the fluorescent probe method, the detection limit of this reaction is also affected by the reaction constants of ·OH and spin‐traps.…”

Free radical scavenging activity of novel thiazolidine‐2,4‐dione derivatives

“…All reagents for synthesis were purchased from E. Merck (Darmstadt, Germany) and Aldrich (Milwaukee, MI, USA). 4,5-Dihydroxy-1,3-benzene-disulfonic acid (Tiron), 5,5-dimethyl-1-pyrroline-1-oxide (DMPO), 6-hydroxy-2,5,7,8-tetramethyl-2 carboxylic acid (Trolox), 18-crown-6 (1,4,7,10,13,16) hexaoxacy clooctadecane and ascorbic acid were from Merck (Darmstadt, Germany); potassium superoxide (KO 2 ) and ammonium ferrous sulfate hexahydrate were from Fluka (Buchs, Switzerland); and p-nitroblue-tetrazolium chloride was from Sigma (St Louis, MO, USA). Anhydrous dimethyl sulfoxide (DMSO) was purchased from Aldrich (Milwaukee, WI, USA).…”

“…The investigation of biological and antioxidant activities of natural substances and natural derivatives having different substituents or even synthetic analogues capable of quenching toxic free radicals, generated under oxidative stress conditions, are the topic of much research (7)(8)(9)(10).…”

Application of an Oxygen Electrode to Evaluate Superoxide Anion-scavenging Ability

“…The conventional methods used to evaluate the • O2 --scavenging activity are electron spin resonance with a spin trapping reagent, 7,8 chemiluminescence with luminol, 9 and colorimetry with nitro blue tetrazolium (NBT). …”