有机相脂肪酶催化合成乙酸肉桂酯

对有机相中酶法催化合成乙酸肉桂酯的转酯化反应进行研究。结果发现:Candida anatarctic脂肪酶(Novozyme435)、根霉脂肪酶(Rhizopus niveus lipase)和荧光假单胞菌脂肪酶(Pseudomonas fluore lipase)均有较好的催化活性。同时考察各反应参数(温度、反应溶剂、体系水活度、酰化剂类型、肉桂醇与酰化剂摩尔比、肉桂醇浓度等)对脂肪酶Novozyme435合成乙酸肉桂酯反应的影响,确定了反应体系最优工艺条件:在10 mL甲基叔丁基醚中,肉桂醇200 mmol/L,n(肉桂醇)∶n(乙酸乙烯酯)=1∶1.5,初始水活度αw=0.84,温度35℃,酶加量0.02 g,反应3 h后肉桂醇转化率可达到99%,产物经质谱(MS)鉴定。固定化酶经过10个批次反应,反应转化率都保持在90%以上。

Lipase-catalyzed synthesis of cinnamyl acetate in organic solvents

Enzymatic transesterification of cinnamyl alcohol with vinyl acetate in organic solvents was studied.Lipase from Candida anatarctic,Rhizopus niveus,and Pseudomonas fluore possessed good catalytic activity.The effects of the reaction parameters catalyzed by Novozyme435 were systematically investigated and the optimum operations were obtained as follows: cinnamyl alcohol 200 mmol/L,cinnamyl alcohol/vinyl acetate(mol/mol) ratio 1∶1.5,initial water activity αw =0.84,reaction temperature of 30 ℃,with 0.02 g lipase in 10 mL methyl tert-butyl ether.Under the above optimum conditions,the maximum reaction conversion reached 99% after 3 h.The product was identified by mass spectory(MS).The lipase was stable when reused for 10 times,and the reaction conversion was above 90%.