Purpose
We happened to synthesize by chance a novel drug called “Substance X” with antioxidative activity during an attempt to synthesize a known other drug. Here we report the dose-dependent free radical scavenging activity of Substance X against multiple free radicals.
Methods
Free radical scavenging activity of Substance X was evaluated against following nine species of free radicals by electron spin resonance spectroscopy with the spin-trapping method: hydroxyl radical, superoxide anion, tert-butyl peroxyl radical,tert-butoxyl radical, ascorbyl free radical, singlet oxygen, nitric oxide, DPPH and tyrosyl radical. By fitting sigmoid dose-response curves, reaction rate constants of Substance X with free radicals studied were estimated. Antioxidative activity against tissue lipids was assessed by TBARS assay.
Results
Substance X significantly scavenged all the free radicals examined in dose-dependent manners. The reaction rate constants of Substance X with some species of free radicals were significantly larger than those of edaravone. The inhibition of lipid oxidation by Substance X was comparable to that by edaravone.
Conclusions
Substance X dose-dependently scavenged multiple free radicals with reaction rate constants comparable to those of edaravone. It is speculated that the direct free radical scavenging activity might contribute to the antioxidative activity of Substance X. Patent pending.