论文部分内容阅读
目的:合成8种新型咪唑类氮氧自由基(4a~4h),并探讨其对1,1-二苯基-2-三硝基苯肼自由基(DPPH)的清除作用。方法:本文以2-硝基丙烷为原料,经烷基化、还原、缩合及氧化反应等步骤,合成8种新型咪唑类氮氧自由基(4a~4h)。将4a~4h分别与DPPH作用,使用紫外-可见分光光度法测定其中DPPH的浓度,考察4a~4h对DPPH自由基的清除作用,以四甲基哌啶氮氧自由基(Tempol)作为阳性对照。结果:合成中间体及终产物经~1H NMR、HRMS、EPR等光谱数据确证了结构。通过DPPH自由基清除实验,结果显示所合成的8种新型咪唑类氮氧自由基对DPPH均有清除作用。结论:合成了新型咪唑类氮氧自由基,并对其合成方法进行了重要改进。在对DPPH自由基清除能力方面,8种化合物在一定浓度范围(0.01μmol/mL-2.4μmol/mL)内,清除作用与浓度成依赖性增长关系。其中,4b与Tempol相当,4a优于阳性对照Tempol,具有进一步开发研究的潜在价值。
OBJECTIVE: To synthesize eight novel imidazole nitroxides (4a ~ 4h) and explore their scavenging effects on 1,1-diphenyl-2-trinitrophenylhydrazine free radical (DPPH). Methods: Eight kinds of novel imidazole nitroxides (4a ~ 4h) were synthesized by 2-nitropropane as alkylation, reduction, condensation and oxidation. The effect of DPPH on the membrane was observed after 4 to 4 hours respectively. The DPPH radical scavenging activity was determined by UV-Vis spectrophotometry. The scavenging effect on DPPH radical from 4a to 4h was investigated. Tempol was used as positive control . Results: The structures of the synthesized intermediates and final products were confirmed by 1H NMR, HRMS and EPR. By DPPH free radical scavenging experiments, the results show that the eight novel imidazole nitroxide scavenging DPPH scavenging effect. Conclusion: A novel imidazole nitroxide has been synthesized and its synthesis has been greatly improved. In the DPPH free radical scavenging capacity, the eight compounds in a certain concentration range (0.01μmol / mL-2.4μmol / mL) scavenging effect and concentration-dependent growth. Among them, 4b is similar to Tempol, and 4a is better than the positive control Tempol, which has the potential value of further research and development.