双羟基吡喃酮化合物的合成及清除自由基性能

Synthesis and free radical scavenging properties of dihydroxypyranone compounds

摘要:

以麦芽酚或乙基麦芽酚为起始原料，经乙酰化、钯碳氢化、羰基α位乙酰氧化和脱乙酰基等4步反应，合成了两种双羟基吡喃酮化合物。利用核磁共振氢谱、碳谱和高分辨质谱对每一步反应产物进了结构表征，优化了合成反应工艺，并通过清除自由基反应对化合物的抗氧化活性进行了测试。结果表明，双羟基吡喃酮化合物对ABTS+?、DPPH?和galvinoxyl?三种自由基清除率分别达到88.9%、83.8%和68.4%，明显高于维生素E和2,6-二叔丁基对甲酚的自由基清除率，表现出优异的抗氧化活性。构效关系研究表明，在吡喃酮结构中引入羟基或增强侧链取代基的给电子能力均能提高化合物清除自由基的能力，为新型抗氧化剂的合成开发提供了参考。

Abstract:

Two dihydroxypyranone compounds were synthesized by acetylation, palladium hydrogenation, carbonyl α-acetoxylation and deacetylation from maltol or ethyl maltol. The structure of each reaction products were characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry, the synthesis process was optimized, and the antioxidant activity of the compounds were tested by quenching free radical reaction system. The results showed that the scavenging rates of dihydroxypyranone on ABTS+?, DPPH? and galvinoxyl? were 88.9%, 83.8% and 68.4% respectively, which were significantly higher than those of vitamin E and butylated hydroxytoluene. The structure-activity relationship study shows that the introduction of hydroxyl groups into the structure of pyranone or the enhancement of the electron donating ability of side chain substituents can improve the free radical scavenging ability of compounds, which provides a reference for the synthesis and development of new antioxidants.