| 1. |
- Mattson, A., et al.
(författare)
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Kinetic resolution of chiral auxiliaries with C-2-symmetry by lipase-catalyzed alcoholysis and aminolysis
- 1996
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Ingår i: Acta Chemica Scandinavica. - : Danish Chemical Society. - 0904-213X .- 1902-3103. ; 50:10, s. 918-921
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Tidskriftsartikel (refereegranskat)abstract
- Three cyclic diols, 1,2-cyclohexanediol (1), 1,3-cyclohexanediol (2), and 1,3-cyclopentanediol (3), two acyclic unsaturated diols, 1,5-hexadiene-3,4-diol (4) and 1,7-octadiyne-3,6-diol (5), and a cyclic diamine, 1,2-cyclohexanediamine (6), have been kinetically resolved in alcoholysis and aminolysis reactions, catalyzed by Candida antarctica component B lipase, using S-ethyl thiooctanoate or ethyl octanoate as acyl donors. Acceptable stereoselectivity was achieved in most cases.
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| 2. |
- OHRNER, N, et al.
(författare)
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THIOETHYL-OCTANOATE, VINYL-OCTANOATE, ETHYL-OCTANOATE ESTERS AND OCTANOIC-ACID AS ACYL DONORS IN LIPASE-CATALYZED ACYL TRANSFER-REACTIONS
- 1994
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Ingår i: BIOCATALYSIS. - ROYAL INST TECHNOL,DEPT ORGAN CHEM,S-10044 STOCKHOLM 70,SWEDEN. : HARWOOD ACAD PUBL GMBH. - 0886-4454. ; 9:1-4, s. 105-114
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Tidskriftsartikel (refereegranskat)abstract
- S-Ethyl thiooctanoate, vinyl octanoate, ethyl octanoate and octanoic acid were studied as acyl donors in a lipase catalysed acyl transfer reaction with 2-octanol as acyl acceptor. The reaction conditions had a pronounced effect on the equilibrium displacement and the apparent enantioselectivity. The thioethyl and vinyl esters proved to be efficient acyl donors under atmospheric pressure and 39-degrees-C, affording a high apparent enantiomeric ratio. Under these reaction conditions the apparent enantioselectivity seemed to be enhanced by water, which was present in the reaction system and caused the production of octanoic acid, by hydrolysis of the acyl enzyme.
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| 3. |
- Uppenberg, J, et al.
(författare)
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Crystallographic and molecular-modeling studies of lipase B from Candida antarctica reveal a stereospecificity pocket for secondary alcohols.
- 1995
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Ingår i: Biochemistry. - 0006-2960. ; 34:51, s. 16838-51
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Tidskriftsartikel (refereegranskat)abstract
- Many lipases are potent catalysts of stereoselective reactions and are therefore of interest for use in chemical synthesis. The crystal structures of lipases show a large variation in the shapes of their active site environments that may explain the large variation in substrate specificity of these enzymes. We have determined the three-dimensional structure of Candida antarctica lipase B (CALB) cocrystallized with the detergent Tween 80. In another crystal form, the structure of the enzyme in complex with a covalently bound phosphonate inhibitor has been determined. In both structures, the active site is exposed to the external solvent. The potential lid-forming helix alpha 5 in CALB is well-ordered in the Tween 80 structure and disordered in the inhibitor complex. The tetrahedral intermediates of two chiral substrates have been modeled on the basis of available structural and biochemical information. The results of this study provide a structural explanation for the high stereoselectivity of CALB toward many secondary alcohols.
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