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篇目详细内容 |
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【篇名】 |
Regioselective acylation of pyridoxine catalyzed by immobilized lipase in ionic liquid |
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【刊名】 |
Frontiers of Chemical Engineering in China |
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【刊名缩写】 |
Front. Chem. Eng. China |
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【ISSN】 |
1673-7369 |
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【EISSN】 |
1673-7474 |
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【DOI】 |
10.1007/s11705-008-0060-x |
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【出版社】 |
Higher Education Press and Springer-Verlag |
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【出版年】 |
2008 |
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【卷期】 |
2
卷3期 |
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【页码】 |
301-307
页,共
7
页 |
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【作者】 |
BAI Shu;
REN Mengyuan;
WANG Lele;
SUN Yan;
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【关键词】 |
Pyridoxine; ionic liquid; lipase; acylation; regioselectivity |
【摘要】 |
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The regioselective acylation of pyridoxine catalyzed by immobilized lipase (Candida Antarctica) in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6) has been investigated, and compared with that in acetonitrile (ACN). The acetylation of pyridoxine using acetic anhydride in [BMIM]PF6 gave comparable conversion of pyridoxine to 5-monoacetyl pyridoxine with considerably higher regioselectivity (93%–95%) than that in ACN (70%–73%). Among the tested parameters, water activity (aw) and temperature have profound effects on the reaction performances in either [BMIM]PF6 or ACN. For the reaction in [BMIM]PF6, higher temperature (50°C–55°C) and lower aw (<0.01) are preferable conditions to obtain better conversion and regioselectivity. Mass transfer limitation and intrinsic kinetic from the ionic nature of ionic liquids (ILs) may account for a different rate-temperature profile and a lower velocity at lower temperature in [BMIM]PF6-mediated reaction. Moreover, consecutive batch reactions for enzyme reuse also show that lipase exhibited a much higher thermal stability and better reusability in [BMIM]PF6 than in ACN, which represents another advantage of ILs as an alternative to traditional solvents beyond green technology. |
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