Enantioselective Hydrolysis of N-Acylated α-Amino Esters at a Biphasic Interface:  Tandem Reaction Kinetic Resolution Using a Chiral Complexing Agent

2002 ◽  
Vol 4 (19) ◽  
pp. 3283-3286 ◽  
Author(s):  
Seth E. Snyder ◽  
William H. Pirkle
Keyword(s):  
Kinetic Resolution ◽  
Reaction Kinetic ◽  
Tandem Reaction ◽  
Complexing Agent ◽  
Enantioselective Hydrolysis ◽  
Amino Esters ◽  
Hydrolysis Of

Isolation of an esterase-producing Trichosporon brassicae and its catalytic performance in kinetic resolution of ketoprofen

2001 ◽  
Vol 47 (12) ◽  
pp. 1101-1106 ◽  
Author(s):  
Duan Shen ◽  
Jian-He Xu ◽  
Peng-Fei Gong ◽  
Hui-Yuan Wu ◽  
You-Yan Liu
Keyword(s):  
Ethyl Ester ◽  
Sole Carbon Source ◽  
Kinetic Resolution ◽  
Enantiomeric Excess ◽  
Catalytic Performance ◽  
Soil Samples ◽  
Enantioselective Hydrolysis ◽  
Resting Cells ◽  
Enantiomeric Ratio ◽  
Hydrolysis Of

A yeast strain CGMCC 0574, identified as Trichosporon brassicae, was selected from 92 strains for its high (S) selectivity in the hydrolysis of ketoprofen ethyl ester. The effective strains of the microorganisms were isolated from soil samples with the ester as the sole carbon source. The ethyl ester proved to be the best substrate for resolution of ketoprofen among several ketoprofen esters examined. The resting cells of CGMCC 0574 could catalyze the hydrolysis of ketoprofen ethyl ester with an enantiomeric ratio of 44.9, giving (S)-ketoprofen an enantiomeric excess of 91.5% at 42% conversion.Key words: ketoprofen, biocatalytic resolution, enantioselective hydrolysis, microbial esterase, Trichosporon brassicae.

scholarly journals Free and Immobilized Lecitase™ Ultra as the Biocatalyst in the Kinetic Resolution of (E)-4-Arylbut-3-en-2-yl Esters

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1067 ◽  
Author(s):  
Aleksandra Leśniarek ◽  
Anna Chojnacka ◽  
Radosław Drozd ◽  
Magdalena Szymańska ◽  
Witold Gładkowski
Keyword(s):  
Reaction Time ◽  
Phosphate Buffer ◽  
Cyanogen Bromide ◽  
Kinetic Resolution ◽  
Immobilized Enzyme ◽  
Acyl Chain ◽  
Enantioselective Hydrolysis ◽  
Acyl Chain Length ◽  
Solvent Type ◽  
Hydrolysis Of

The influence of buffer type, co-solvent type, and acyl chain length was investigated for the enantioselective hydrolysis of racemic 4-arylbut-3-en-2-yl esters using Lecitase™ Ultra (LU). Immobilized preparations of the Lecitase™ Ultra enzyme had significantly higher activity and enantioselectivity than the free enzyme, particularly for 4-phenylbut-3-en-2-yl butyrate as the substrate. Moreover, the kinetic resolution with the immobilized enzyme was achieved in a much shorter time (24–48 h). Lecitase™ Ultra, immobilized on cyanogen bromide-activated agarose, was particularly effective, producing, after 24 h of reaction time in phosphate buffer (pH 7.2) with acetone as co-solvent, both (R)-alcohols and unreacted (S)-esters with good to excellent enantiomeric excesses (ee 90–99%). These conditions and enzyme were also suitable for the kinetic separation of racemic (E)-4-phenylbut-3-en-2-yl butyrate analogs containing methyl substituents on the benzene ring (4b,4c), but they did not show any enantioselectivity toward (E)-4-(4’-methoxyphenyl)but-3-en-2-yl butyrate (4d).

scholarly journals Application of Lecitase® Ultra-Catalyzed Hydrolysis to the Kinetic Resolution of (E)-4-phenylbut-3-en-2-yl Esters

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 423 ◽  
Author(s):  
Aleksandra Leśniarek ◽  
Anna Chojnacka ◽  
Witold Gładkowski
Keyword(s):  
Kinetic Resolution ◽  
Enantiomeric Excess ◽  
Optical Purity ◽  
Enantioselective Hydrolysis ◽  
Hydrolysis Of ◽  
Allyl Esters

The possibility of using Lecitase® Ultra as a novel alternative biocatalyst for the kinetic resolution of model racemic allyl esters of (E)-4-phenylbut-3-en-3-ol: Acetate (4a) and propionate (4b) through their enantioselective hydrolysis was investigated. Reaction afforded (+)-(R)-alcohol (3) and unreacted (−)-(S)-ester (4a or 4b). Hydrolysis of propionate 4b proceeded with higher enantioselectivity than acetate 4a. (R)-Alcohol (3) with highest enantiomeric excess (93–99%) was obtained at 20–30 °C by hydrolysis of propionate 4b, while the highest optical purity of unreacted substrate was observed for (S)-acetate 4a (ee = 34–56%). The highest enantioselectivity was found for the hydrolysis of propionate 4b catalyzed at 30 °C (E = 38). Reaction carried out at 40 °C significantly lowered enantiomeric excess of produced alcohol 3 and enantioselectivity in resolution. Lecitase® Ultra catalyzed the enantioselective hydrolysis of allyl esters 4a,b according to Kazlauskas’ rule to produce (R)-alcohol 3 and can find application as a novel biocatalyst in the processes of kinetic resolution of racemic allyl esters.

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