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文献总结

文献总结. 学生 常盼盼 指导老师 唐老师 赵老师 . 目录. 1. 离子液体 2.IL 中的酶催化 3.CO 2 中的酶催化 4.IL 和超临界二氧化碳中的脂肪酶催化反应. 1. 离子液体. 离子液体由带正电的离子和带负电的离子组成，多指在低于 100 ℃时呈液体状态的熔盐。. 常见的阳离子和阴离子. 阴离子有 卤素离子 、硝酸盐、醋酸盐、三氟醋酸盐、四氟硼酸根、三氟甲烷磺酸、六氟磷酸盐 、（三氟甲烷磺酰基） 2- 酰亚胺、碳硼烷阴离子. 离子液体的应用. 挑战和机遇. 2.IL 中的酶催化.

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文献总结

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  1. 文献总结 学生 常盼盼 指导老师 唐老师 赵老师

  2. 目录 • 1.离子液体 • 2.IL中的酶催化 • 3.CO2中的酶催化 • 4.IL和超临界二氧化碳中的脂肪酶催化反应

  3. 1.离子液体 • 离子液体由带正电的离子和带负电的离子组成，多指在低于100℃时呈液体状态的熔盐。

  4. 常见的阳离子和阴离子 • 阴离子有卤素离子、硝酸盐、醋酸盐、三氟醋酸盐、四氟硼酸根、三氟甲烷磺酸、六氟磷酸盐 、（三氟甲烷磺酰基）2-酰亚胺、碳硼烷阴离子

  5. 离子液体的应用

  6. 挑战和机遇

  7. 2.IL中的酶催化 • 优点：高选择性、高反应速率和高的酶稳定性 • 缺点：纯化IL、水活度控制、pH、高黏度、产品分离

  8. Ionic liquids do not inactivate enzymes like polar organic solvents • Although polar organic solvents inactivate enzymes ，surprisingly ionic liquids do not; this feature extends enzyme-catalyzed reactions to a solvent polarity range that was previously inaccessible. The ability to use solvents with greater polarity increases the solubility of polar substrates, such as glucose, maltose or ascorbic acid.

  9. Increased stability of enzymes in ionic liquids • 常用酶：hydrolases and oxidoreductases • 常用IL： ionic liquids containing BF4, PF6, and NTf2 anions, but not in ionic liquids containing Cl, NO3, CF3SO3, trifluoroacetate or acetate anions

  10. Other advantages • 1. In some cases lipases and proteases are more enantioselectivein ionic liquids than organic solvents • 2. As ionic liquids are nonvolatile, a vacuum can be used to remove volatile products such as alcohol and water, driving the equilibrium towards product formation • 3. Ionic liquids are ‘tailored solvents’, because it is easier to change their structure

  11. Product isolation

  12. 3.CO2中的酶催化

  13. 反应速率提高 • 可通过压力温度来控制反应的选择性

  14. 1 密度大的变化也可能极大的改变二氧化碳和酶之间的交互作用（通过在酶分子的表面形成氨基甲酸盐和aa） 2 CO2在酶分子上的吸附或者CO2分子参与到底物与酶分子之间的结合键中 绿脓假单胞菌 皱落假丝酵母 洋葱假单胞菌 南极假丝酵母

  15. 4.IL和超临界二氧化碳中的脂肪酶催化反应

  16. 两相系统实例

  17. 两相系统的优缺点 优点：1.有机金属和E在IL中的高溶解度，高稳定性 2.CO2使得产品分离简单 缺点：1.超临界装置成本高 2.IL的毒性和其他理化性质未知

  18. Lipases • Lipases are widely available in nature and broadly used in chemical reactions, such as ester hydrolysis, esterification, amidationtransesterification. • lipases accept a wide variety of substrates while maintaining their regioselectivity and stereoselectivity. Applications of lipases are very wide, including food additives, chiral intermediates in pharmaceutical products and pesticide products.

  19. Lipase catalysis • Lipases catalyze hydrolysis of triglycerides to the corresponding fatty acids and glycerol in nature. • Because of their ready availability, low cost of production, and enormous utilities in organic syntheses, lipases are used widely in industry and in laboratory.

  20. Advantages of using IL/SC-CO2 biphasic system in lipase-catalyzed reactions 在IL中E 活性较高的原因 1. E的高活性和高选择性 2.催化剂的过稳定化 • 1. the system could have a stabilizing effect against enzyme deactivation caused by SC-CO2 as the reaction medium alone. • 2. the combination of ILs and SC-CO2 is helpful to solve the problems of ILs used alone, which caused product separation and IL recycling.

  21. Mass transfer of lipase catalysis in the ionic liquids/SC-CO2 E固定在离子液体相 底物在CO2相

  22. 包含IL的支撑体不仅对脂肪酶的水解提供了一个适当的微环境,而且改善了在SC-CO2中疏水性底物和产品的传质现象　　包含IL的支撑体不仅对脂肪酶的水解提供了一个适当的微环境,而且改善了在SC-CO2中疏水性底物和产品的传质现象　　

  23. Characteristics of the lipase catalysis in IL/SC-CO2 • 1.超临界状态下，温度的升高会使E的活性有轻微的下降。 • 2. 不同IL对E的活性保持不一样。 • 3. 有IL存在时，E的半衰期比游离酶高很多。 • 4. E的固定化会显著提高E的稳定性（使E得结构“僵化”）。 • 5. E与水溶性或非水溶性介质之间形成的H键会增加其热稳定性。

  24. Kinetic model for butyl propionate synthesis catalyzed by CALB in IL/SC-CO2 biphasic systems 生成丙酸丁酯和游离酶 酶和丙酸乙烯 酯形成脂肪酶 乙烯醇复合物 脂肪酶乙烯醇 异构化为脂肪 酶乙醛类 和丁醇形成二级复合物 酶丁醇 复合物

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