脂肪酶Novozym 435催化合成羟基酪醇油酸酯Synthesis of hydroxytyrosyl oleate catalyzed by lipase Novozym 435

羟基酪醇是一种标志性多酚，其油溶性差且容易降解，将羟基酪醇修饰为油酸酯是提高其油溶性的有效途径。对羟基酪醇油酸酯的酶法合成进行了研究，考察了脂肪酶种类、酶添加量、醇酸摩尔比、溶剂(2-甲基-2-丁醇)用量、反应时间对合成反应的影响，并利用Box-Behnken中心组合的响应面设计优化了羟基酪醇油酸酯的合成反应条件。另外，采用质谱和核磁分析对产物进行了表征。结果表明：羟基酪醇油酸酯合成的最佳工艺条件为羟基酪醇500 mg、油酸2.474 g(醇酸摩尔比1∶ 2.7)、脂肪酶Novozym 435添加量2.2%(以整个反应体系的质量为基准)、溶剂用量2.6 mL、反应温度37 ℃和反应时间7 h，在此条件下羟基酪醇转化率高达89.6%；质谱和核磁分析证明成功合成了羟基酪醇油酸酯。脂肪酶催化合成羟基酪醇油酸酯的技术突破，可为延伸油橄榄产业链及副产物高值利用提供有力支撑。 Hydroxytyrosol is a major polyphenol, it has poor oil solubility and is prone to degrade. Modifying hydroxytyrosol into hydroxytyrosyl oleate is an effective way to improve hydroxytyrosol′s oil solubility. The enzymatic synthesis of hydroxytyrosyl oleate was constructed, and the effects of lipase type, enzyme dosage, molar ratio of hydroxytyrosol to oleic acid, solvent （2-methyl-2-butanol）dosage and reaction time on the synthesis of hydroxytyrosyl oleate were investigated. Then, the enzymatic synthesis conditions of hydroxytyrosyl oleate was optimized by response surface design of Box-Behnken central combination. In addition, the product was characterized by mass spectrometry and nuclear magnetic analysis. The results showed that the optimal synthesis conditions of hydroxytyrosyl oleate were obtained as follows: hydroxytyrosol dosage 500 mg, oleic acid dosage 2.474 g (molar ratio of hydroxytyrosol to oleic acid 1∶ 2.7), lipase Novozym 435 dosage 2.2% (based on the reaction system mass), solvent dosage 2.6 mL, reaction temperature 37 ℃ and reaction time 7 h. Under the optimal conditions, the conversion rate of hydroxytyrosol was the highest, reaching 89.6%. Mass spectrometry and nuclear magnetic analysis showed that the hydroxytyrosyl oleate was successfully synthesized. The technological breakthrough in the lipase-catalyzed synthesis of hydroxytyrosyl oleate can not only strengthen the extension of the olive industry chain, but also promote the high-value utilization of the by-products in the olive industry.