固载化Co(salen)/固载化漆酶催化氧化4-甲基愈创木酚制备香兰素

Catalytic Oxidation of 4-methyl Guaiacol to Vanillin by Immobilized Co( salen)-immobilized Laccase

以4-甲基愈创木酚为底物(100 mg),固载化Co(salen)-固载化漆酶为催化剂,对制备香兰素的实验条件进行优化,其中主要影响因素有H2O2用量(0.5~2.5 m L)、反应pH值(3~11)、反应时间(2~6 h)、催化剂总用量(0.5~2.5 mg)、催化剂比例(固载化Co(salen)∶固载化漆酶:1∶1~3∶1)以及亚油酸钠用量(0.04~0.20 mg),通过正交实验得到初步反应条件:H2O2用量0.5 m L,反应时间4 h,pH值9,催化剂总用量2.0 mg,催化剂比例1∶1,亚油酸钠用量0.04 mg;同时进一步通过单因素实验优化后得到最佳反应条件为:反应总体积为100 m L时,H2O2用量1.5 m L,pH=8,反应时间4 h,催化剂总用量2.5 mg,催化剂比例为1∶2;亚油酸钠用量为0.07 mg.最后得到结论:固载化Co(salen)-固载化漆酶组合催化4-甲基愈创木酚转化的效果比两者单独催化的效果好;加入亚油酸钠可以提高4-甲基愈创木酚催化转化的效果;在最佳反应条件下,固载化Co(salen)和固载化漆酶催化氧化4-甲基愈创木酚制备得到的香兰素收率可达70%以上.

The experimental conditions for the preparation of vanillin were optimized by using 4-methyl guaiacol as the substrateandimmobilized Co(salen)/immobilized laccase as the catalyst.The main influencing factors were amount of hydrogen peroxide(0.5~2.5 m L),pH(3~11),reaction time(2~6 h),total amount of catalyst(0.5~2.5 mg),ratio of catalyst(immobilized Co(salen)∶immobilized laccase:1∶1~3∶1),and amount of sodium linoleate(0.04~0.20 mg).The preliminary reaction conditions obtained via orthogonal experiment were H2 O2 dosage 0.5 m L,reaction time 4 h,p H 9,total catalyst dosage 2.0 mg,catalystproportion 1∶1,sodium linoleate dosage 0.04 mg;the vintage reaction conditions were further optimized by single factor experiment:when the total volume of the reaction is 100 m L,the dosage of H2 O2 was 1.5 m L,the pH was 8,the reaction time was 4 h,the total amount of catalyst was 2.5 mg,and the catalyst ratio was 1∶2.The amount of sodium linoleate is 0.07 mg.Finally,it was concluded that the combined catalytic effect of immobilized Co(salen)/immobilized laccase was better than that of the two catalysts alone in the conversion of 4-methyl guaiacol.Sodium oleate can improve the catalytic conversion of 4-methyl guaiacol.In the optimum reaction conditions,the yield of vanillin can reach more than 70%during the catalytic oxidation of 4-methyl guaiacol with immobilized Co(salen)/immobilized laccase.