Study of the Mechanism and Kinetics of the Radical Scavenging Activity of 2-Mercaptoimidazole

2-Mercaptoimidazole(2MI) is related to natural ovothiolsthat are recognized as powerful radical scavengers. Yet, despite earlyreports of its potent antioxidant properties, 2MI receivedlittle attention. Specifically, its radical scavenging activity againsttypical free radicals like HO center dot and HOO center dot has not yet been studied in terms of its mechanism and kinetics.In this project, density functional theory (DFT) simulations wereused to assess the antiradical activity of 2MI. Calculationsindicate that 2MI can demonstrate anti-HO center dot activity in both lipid and aqueous environments (k (overall) of 1.05 x 10(10) and 2.07 x10(10) M-1 s(-1), respectively).The calculated kinetics is extremely close to the experimental datain water (pH = 7.0), resulting in a k (calculated)/k (experimental) ratio of 1.73, validatingthe accuracy of the computational method and its usefulness for assessingradical scavenging activity in silico. In lipid media, the HOO center dot radical scavenging activity of 2MI isfaster than that of common typical natural scavengers such as ascorbicacid, Trolox, and trans-resveratrol; hence, 2MI is apowerful radical scavenger in nonpolar media.