纳米金辅助微波耦合脂肪酶催化阿魏酸淀粉酯的合成

Gold Nanoparticles Assisted Microwave Coupling Lipase Catalyzed Synthesis of Ferulic Acid Starch Ester

以预处理玉米淀粉和阿魏酸乙酯为原料,在非水相体系中进行微波耦合脂肪酶催化阿魏酸淀粉酯合成的研究。拟向反应体系中加入纳米金提高酶促反应活性。研究发现在常规加热条件下纳米金的加入并不能明显改变酶促反应活性,但在微波反应器中进行酶促阿魏酸淀粉酯合成时,纳米金的加入会明显提高阿魏酸淀粉酯的取代度。而此时,纳米金的用量及粒径大小会对酶促反应产生明显影响。利用紫外分光光度计对阿魏酸淀粉酯取代度进行测定,并以取代度为考察指标研究各因素对阿魏酸淀粉酯合成的影响。当在微波功率为80 W,反应时间为120 min,纳米金粒径为700 nm,纳米金用量为0.8%的条件下,阿魏酸淀粉酯的取代度最高为0.179 8,较现有研究提高一个数量级的同时也大大缩短反应时间。并通过紫外色谱以及~1H NMR对产物进行定性分析。

Ferulic acid starch ester （FASE） was biosynthesised by lipase as the catalysis under the microwave in non-aqueous system. The pretreatment starch and ethyl ten＇ate was used as the substrate. Gold nanoparticles （AuNPs） has been added to improve the degree of substitution （DS） of terulic acid starch ester. It was tound that the addition of AuNPs could not significantly change the enzymatic reactivity under conventional heating, but the DS of FASE could be significantly increased in microwave reactor when the synthesis of FASE was catalyzed by lipase. At this point, the amount and the size of AuNPs had a significant impact on the enzymatic. The degree of substitution of the product was determined by ultraviolet spectrophotometer. The eiiect of reaction reaction conditions on the synthesis of FASE was studied by using DS of terulic acid starch ester as index. When the microwave power was 80 W, the reaction time was 120 min, the size of AuNPs was 700 nm, and the amount of AuNPs was 0.8 %, the DS of FASE was as high as 0.179 8, isting research. It also greatly reduced the reaction time. The tmphotometer and ^1H NMR which is an order of magnitude higher than the ex FASE was qualitative analyzed by ultraviolet spec