肉桂酸蔗糖酯的酶法制备及其抗菌活性

Lipase-catalyzed Synthesis of Cinnamate Sucrose Ester and Its Antibacterial Activity

摘要:

本文主要研究了利用脂肪酶催化蔗糖与肉桂酸合成制备肉桂酸蔗糖酯的过程及其抗菌性能。该制备过程以DMAc/叔戊醇双溶剂体系为反应介质，用以溶解极性底物糖并保持脂肪酶的良好活性，同时探索了混合溶剂体积比和反应温度对酶法合成的影响。对产物的红外光谱分析，表明蔗糖与肉桂酸在脂肪酶催化下发生了酯化反应；进一步对产物的13C-NMR分析，表明酯化反应发生在蔗糖的C-6位点上；对产物的TGA分析，表明制备的肉桂酸蔗糖酯具有较高的热稳定性。同时，酯化产物对大肠杆菌和白地霉具有明显的抑制作用，其抑菌率分别为97.83%和96.04%。此外，肉桂酸蔗糖酯还具有良好的保湿效果，保水率为76%。综合评价产物肉桂酸蔗糖酯的抑菌性能、热稳定性和两亲特性，其在食品、日化等领域将具有广阔的应用前景。

Abstract:

A feasible route for lipase-catalyzed synthesis of sucrose ester with excellent antibacterial properties was developed in this paper. Binaryorganic solvent of DMAc and tert-amyl alcohol was used as the reaction medium to well dissolve the polar sugar substrate and maintain the enzyme activity of immobilized lipase. And the effect of solvent volume ratio and reaction temperature on the synthesis method was explored. The FTIR of ester product showed that the lipase promoted the acylation of sucrose with cinnamic acid. The structure of ester product was further identified by 13C-NMR spectrum and it confirmed that esterification occurred on the C-6 cite of sucrose. TGA analysis showed a high thermal stability of cinnamate sucrose ester. And the antimicrobial activity of cinnamate sucrose ester was determined, the inhibitory rates of the ester product to Escherichia coli and Geotrichum candidum were 97.83% and 96.04%, respectively. Furthermore, the cinnamate sucrose ester showed great water retention property and the water retention rate was 76%. The findings are of importance for the application of sucrose ester in food and cosmetics industry.