Quy Huong Dinh, Nam Pham Cam, Quang Duong Tuan, Ngo Son Tung, Duong Tran, Tam Nguyen Minh
Department of Chemistry, University of Education, Hue University, Hue 530000, Vietnam.
Department of Chemical Engineering, The University of Danang - University of Science and Technology, Danang 550000, Vietnam.
ACS Omega. 2024 May 21;9(22):24071-24081. doi: 10.1021/acsomega.4c02931. eCollection 2024 Jun 4.
An assessment of the free radical scavenging potential of 4-amino-5-phenyl-4H-1,2,4-triazole-3-thiol (AT) and 4-amino-5-(4-pyridyl)-4H-1,2,4-triazole-3-thiol (AP) involved a combination of experimental methodologies and theoretical calculations. In the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, AT exhibited an heightened efficacy in scavenging DPPH radicals compared to AP. This was evidenced by the notably lower IC value observed for AT (1.3 × 10 ± 0.2 × 10 M) in comparison to AP (2.2 × 10 ± 0.1 × 10 M). Similarly, in the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS ) test, AT exhibited superior ability in neutralizing ABTS free radical cations compared to AP, with the computed IC values of 4.7 × 10 ± 0.1 × 10 M for AT and 5.5 × 10 ± 0.2 × 10 M for AP. Density functional theory served as the tool for evaluating the correlation between structural attributes and the antioxidant efficacy of the studied molecules. The findings highlighted the flexibility of hydrogen atoms within NH and NH groups to nucleophilic attacks, indicative of their pivotal role in the scavenging mechanism. Furthermore, investigations into the interactions between AT and AP with the free radical HOO revealed predominantly the reaction via the hydrogen atom transfer mechanism. Both experimental observations and theoretical deductions collectively affirmed AT's superior free radical scavenging ability over AP in the gas phase and ethanol.
对4-氨基-5-苯基-4H-1,2,4-三唑-3-硫醇（AT）和4-氨基-5-（4-吡啶基）-4H-1,2,4-三唑-3-硫醇（AP）的自由基清除潜力的评估涉及实验方法和理论计算的结合。在2,2-二苯基-1-苦基肼（DPPH）测定中，与AP相比，AT在清除DPPH自由基方面表现出更高的功效。这一点通过与AP（2.2×10±0.1×10 M）相比，AT的IC值显著更低（1.3×10±0.2×10 M）得到证明。同样，在2,2'-偶氮双（3-乙基苯并噻唑啉-6-磺酸盐）（ABTS）测试中，与AP相比，AT在中和ABTS自由基阳离子方面表现出更强的能力，AT的计算IC值为4.7×10±0.1×10 M，AP的计算IC值为5.5×10±0.2×10 M。密度泛函理论用作评估所研究分子的结构属性与抗氧化功效之间相关性的工具。研究结果突出了NH和NH基团内氢原子对亲核攻击的灵活性，表明它们在清除机制中起关键作用。此外，对AT和AP与自由基HOO之间相互作用的研究主要揭示了通过氢原子转移机制的反应。实验观察和理论推导共同证实了在气相和乙醇中，AT的自由基清除能力优于AP。
