Regioselective acylation of pyridoxine catalyzed by immobilized lipase in ionic liquid
Tóm tắt
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 (a
w) 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 a
w (<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.
Tài liệu tham khảo
Fonda M L. Vitamin B6 metabolism and binding to proteins in the blood of alcoholic and nonalcoholic men. Alcohol Clin Exp Res, 1993, 17: 1171–1178
DeSimone J M. Practical approaches to green solvents. Science, 2002, 297: 799–803
Wasserscheid P, Welton T. Ionic liquids in synthesis. Weinheim: Wiley-VCH, 2003
Dupont J, Souza R F, Suarez P A Z. Ionic liquid (Molten salt) phase organometallic catalysis. Chem Rev, 2002, 102: 3667–3692
Kragl U, Eckstein M, Kaftzik N. Enzyme catalysis in ionic liquid. Curr Opin Biothchnol, 2002, 13: 565–570
Park S, Kazlauskas R J. Biocatalysis in ionic liquids-advantages beyond green technology. Curr Opin Biotechnol, 2003, 14: 432–437
Brennecke J F, Maginne E J. Ionic liquids: Innovative fluids for chemical processing. AIChE J, 2001, 47: 2384–2389
Guo Z, Xu X. New opportunity for enzymatic modification of fats and oils with industrial potentials. Org Biomol Chem, 2005, 3: 2615–2619
Lee S G. Functionalized imidazolium salts for task-specific ionic liquids and their applications. Chem Commun, 2006, 1049–1063
Schöfer S H, Kaftzik N, Wasserscheid P, Kragl U. Enzyme catalysis in ionic liquids: lipase catalysed kinetic resolution of 1-phenylethanol with improved enantioselectivity. Chem Commun, 2001, 425–426
Kim M J, Choi M Lee J K, Ahn Y. Enzymatic selective acylation of glycosides in ionic liquids: Significantly enhanced reactivity and regioselectivity. J Mol Catal B: Enzyme, 2003, 26: 115–118
Li X F, Lou W Y, Smith T J, Zong M H, Wu H, Wang J F. Efficient regioselective acylationof 1-βb-D-arabinofuranosylcytosine catalyzed by lipase in ionic liquid containing systems. Green Chem, 2006, 8: 538–544
Itoh T, Akasaki E, Kudo K, Shirakami S. Lipase-catalysed enantioselective acylation in the ionic liquid solvent system: reaction of enzyme anchored to the solvent. Chem Lett, 2001, 1: 262–263
Baldessari A, Mangone C P, Gros E G. Lipase-catalyzed acylation and deacylation reactions of pyridoxine, a member of Vitamin-B6 group. Helvetica Chimica Acta, 1998, 81: 2407–2413
Wilkes J S. A short history of ionic liquids-from molten salts to neoteric solvents. Green Chem, 2002, 4: 73–80
Song C E. Enantioselective chemo-and bio-catalysis in ionic liquids. Chem Common, 2004, 1033–1043
Barahona D, Pfromm P H, Rezac M E. Effects of water activity on the lipase catalyzed esterification of geraniol in ionic liquid [bmim]PF6. Biotechnol Bioeng, 2005, 93: 318–324
Earle M J, McCormac P B, Seddon K R. The first high yield green route to a pharmaceutical in a room temperature ionic liquid. Green Chem, 2000, 2: 261–262
Huddleston J G, Willauer H D, Swatloki R P. Room temperature ionic liquids as novel media for ‘clean’ liquid-liquid extraction. J Chem Soc Chem Comm, 1998, 1765–1766
Park S, KazlauskasR J. Improved preparation and use of roomtemperature ionic liquids in lipase-catalyzed enantio-and regioselective acylations. J Org Chem, 2001, 66: 8395–8401
Halling P J. Salt hydrates for water activity control with biocatalysis in organic media. Biotechnol Tech, 1992, 6: 271–276
Guo Z, Xu X. Lipase-catalyzed glycerolysis of fats and oils in ionic liquids: a further study on the reaction system. Green Chemistry, 2006, 8: 54–62
Aggarwal A, Lancaster N L, Sethi A R, Welton T. The role of hydrogen bonding in controlling the selectivity of Diels-Alder reactions in room-temperature ionic liquids. Green Chem, 2002, 4: 517–520
Guo Z, Chen B, Murillo R L, Tan T, Xu X. Functional dependency of structures of ionic liquids: do substituents govern the selectivity of enzymatic glycerolysis? Org Biomol Chem, 2006, 4: 2772–2776
Halling P J. Thermodynamic predictions for biocatalysis in nonconventional media: theory, tests, and recommendations for experimental design and analysis. Enzyme Microb Technol, 1994, 16: 178–206
Berberich J A, Kaar J L, Russell A J. Use of salt hydrate pairs to control water activity for enzyme catalysis in ionic liquids. Biotechnol Prog, 2003, 19: 1029–1032
Bell G, Janssen A E M, Halling P J. Water activity fails to predict critical hydration level for enzyme activity in polar organic solvents: interconversion of water concentrations and activities. Enzyme Microb Technol, 1997, 20: 471–477
Lozano P, Carrié D, Vaultier M, Iborra J L. Over-stabilization of Candida antarctica lipase B by ionic liquids in ester synthesis. Biotechnol Lett, 2001, 23: 1529–1533
Park S, Kazlauskas R J. Biocatalysis in ionic liquids-advantages beyond green technology. Curr Opin Biotechnol, 2003, 14: 432–437