新型姜黄素类似物的微波合成及其抗氧化活性

Microwave Synthesis and Antioxidant Activities of Novel Curcumin Analogues

采用微波法,取代苯甲醛分别与环戊酮和环己酮经克莱森-斯密特缩合反应制得中间体2,6-双苯亚甲基环己酮(2a^2e)和2,5-双苯亚甲基环戊酮(5a);2a^2e或5a分别与硫脲或尿素经Biginelli反应合成了8个新型的姜黄素类似物(3a^3e,4a,4c和6a),其结构经1H NMR,13C NMR,IR和MS表征。利用DPPH法比较3~6与姜黄素的抗氧化能力。实验结果表明:3~6的抗氧化能力均比姜黄素母核结构高;3比4和6的自由基清除能力强;随用药量增大,抗氧化能力呈现先增强后下降的趋势,并在0.09 mg·mL-1~0.12 mg·mL-1自由基清除率达最大。

The intermediate analogues, 2,6-diphenyl methylene cyclohexyl ketone （2a -2e） or 2,5- diphenyl methylene eyelopentl ketone（Sa）, were synthesized by Claisen -Schmidt condensation re- action of aromatic aldehyde with cyclohexanone or cyclopentanone. Eight novel curcumin analogues （3a -3e, 4a, 4e and 6a） were synthesized by Biginelli reaction of2a -2e or 5a with urea or thiou- rea under microwave irradiation. The structures were characterized by 1H NMR, 13C NMR, IR and MS. The antioxidant activities of 3 - 6 were investigated by DPPH method. The results showed that the antioxidant abilities of 3 - 6 were higher than cureumin mother structure, and 3 was higher than 4 and 6. The antioxidant abilities increase at first and then decrease with increasing of the dosage, and reach the maximal value at 0.09 mg - mL-l -0.12 mg - mL-1.