Reaction of N-Acetylcysteine with Cu²⁺: Appearance of Intermediates with High Free Radical Scavenging Activity: Implications for Anti-/Pro-Oxidant Properties of Thiols.

ABSTRACT: We studied the kinetics of the reaction of N-acetyl-l-cysteine (NAC or RSH) with cupric ions at an equimolar ratio of the reactants in aqueous acid solution (pH 1.4-2) using UV/Vis absorption and circular dichroism (CD) spectroscopies. Cu²⁺ showed a strong catalytic effect on the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical (ABTSr) consumption and autoxidation of NAC. Difference spectra revealed the formation of intermediates with absorption maxima at 233 and 302 nm (ε₃₀₂/Cu > 8 × 10³ M^-1 cm^-1) and two positive Cotton effects centered at 284 and 302 nm. These intermediates accumulate during the first, O₂-independent, phase of the NAC autoxidation. The autocatalytic production of another chiral

SUBMITTER: Valent I 

PROVIDER: S-EPMC9181168 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature