- Efficient resolution of 3-aryloxy-1,2-propanediols using CLEA-YCJ01 with high enantioselectivity
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The lipase YCJ01 from Burkholderia ambifaria is an organic solvent-stable enzyme and its activity can be activated by a hydrophobic solvent due to the "interface activation" mechanism. The activity of lipase YCJ01 increased by 2.1-fold with t-butanol as the precipitant even after cross-linking. The cross-linked enzyme aggregates of lipase YCJ01 (CLEAs-YCJ01) were found to be efficient for resolving 3-(4-methylphenoxy)-1,2-propanediol (MPPD) through sequential esterification. Excellent enantioselectivity towards MPPD (E > 400), excellent enantiomeric excess (ee) values of 99.2% for S-diacetates and 99.1% for R-monoacetate, and high yield (49.9%) were achieved using a high substrate concentration (180 mmol L-1). Thus, R- and S-type compounds with excellent ee values were simultaneously obtained, and MPPD was resolved by CLEAs-YCJ01. CLEAs-YCJ01 also showed high operational stability and maintained 91.2% residual activity after ten batches. To further evaluate the substrate specificity of CLEAs-YCJ01, a series of 3-aryloxy-1,2-propanediols (six analogues of MPPD) was applied as substrates for resolution. Under the optimized reaction conditions of reaction temperature of 35 °C, MPPD concentration of 180 mmol L-1, molar ratio of vinyl acetate to MPPD of 3 : 1, and isopropyl ether as the solvent, CLEAs-YCJ01 exhibited relatively strict enantioselectivity towards all the analogues of MPPD with a high yield (≥49.3%), favourable ee values (94.8-99.4%) for S-diacetates, and high ee values (92.1-99.2%) for R-monoacetate, which shows potential prospects for industrial applications.
- Wang, Bin,Wu, Bin,He, Bingfang
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p. 13757 - 13764
(2019/05/17)
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- Lipase-catalysed resolution of 3-(aryloxy)-1,2-propanediol derivatives - Towards an improved active site model of Pseudomonas cepacia lipase (Amano PS)
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A variety of 3-(aryloxy)-1,2-propanediol derivatives with different substituents on the aromatic ring or at the primary hydroxy group were used as substrates in a kinetic resolution by transesterification with vinyl acetate catalysed by lipase from Pseudomonas cepacia (Amano PS). Derivatives with substituents in the para-position of the aromatic ring were accepted as substrates and resolved with high enantioselectivity. The corresponding derivatives with substituents in the ortho-position were much worse substrates for lipase PS or even non-substrates if the substituent was sufficiently space-filling as found for the tert-butyl, phenyl, benzyl or benzoyl residue. Otherwise, if the primary hydroxy group was substituted by unbranched long-chain acyl residues very good substrates were resulting. In contrast, derivatives with sterically crowded residues at the primary hydroxy group such as the pivaloyl, tert-butyldimethylsilyl, methansulfonyl, para-toluenesulfonyl or trityl groups were non-substrates for lipase PS.
- Theil,Lemke,Ballschuh,Kunath,Schick
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p. 1323 - 1344
(2007/10/02)
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- Kinetic resolution of acyclic 1,2-diols using a sequential lipase- catalyzed transesterification in organic solvents
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A method for the kinetic resolution of 3-(aryloxy)-1,2-propanediols rac- 1a-n without additional protection-deprotection steps using a lipase- catalyzed sequential transesterification with lipase amano PS has been developed. In the first step of this one-pot procedure the racemic 1,2-diols are acylated regioselectively at the primary hydroxy group without enantioselection. The subsequent acylation at the secondary hydroxy group of the formed primary monoacetate is responsible for high enantioselection. The enantioselectivity of this transformation depends significantly on the substitution pattern of the aryl ring and the organic solvent used. 3- (Aryloxy)-1,2-propanediols with substituents in the para-position show a much higher enantioselectivity than the corresponding derivatives with ortho- substituents. Among other substrates, the pharmaceuticals Mephenesin, Guaifenesin, and Chlorphenesin have been resolved. The replacement of the aryloxy by an alkyl substituent causes a dramatic decrease of enantioselectivity.
- Theil,Weidner,Ballschuh,Kunath,Schick
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p. 388 - 393
(2007/10/02)
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- Kinetic resolution of aliphatic 1,2-diols by a lipase-catalyzed sequential acetylation
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The kinetic resolution of 13 racemic aliphatic 1,2-diols (rac-1a-m) by means of a lipase-catalyzed sequential acetylation was investigated. The enantioselectivity of the 3-aryloxy-propane-1,2-diols rac-1a-k depends on the substitution pattern at the aryl ring.
- Theil, Fritz,Weidner, Judith,Ballschuh, Sibylle,Kunath, Annamarie,Schick, Hans
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p. 305 - 306
(2007/10/02)
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