54004-43-2Relevant academic research and scientific papers
Enhancing the enantioselectivity of CALB by substrate imprinting: A combined experimental and molecular dynamics simulation model study
Chaput,Marton,Pineau,Domon,Tran,Graber
, p. 55 - 61 (2012)
Kinetic resolution of pentan-2-ol by CALB catalyzed enantioselective transesterification, with various alkylpropanoate acyl donors, was studied in a solid-gas reactor. Results show that the leaving alkoxy group influences the enantiomeric ratio of the reaction. Resolution of pentan-2-ol with methyl propanoate gives an enantiomeric ratio of 62. Esters with longer linear alkyl chains, from ethyl to pentyl propanoate give higher enantiomeric ratios, comprised between 103 and 117. Enantiopure ester (R)-1-methylpentyl propanoate increases the enantiomeric ratio to 140 compared with E = 120 for the racemic mixture. In contrast, enantiopure (S)-1-methylpentyl propanoate decreases the enantiomeric ratio to 72. Our data support the notion of an imprinting effect or ligand-induced enzyme memory caused by the shape of the leaving alcohol. To simulate the imprinting effect caused by the alkoxy part of the acyl donor, molecular modeling studies were performed with both (R)- and (S)-enantiopure 1-methylpentyl propanoate. To investigate how the first step of the reaction, through the first tetrahedral intermediate, affects the enzyme conformation depending on the enantiopure ester substrate used, 20 ns molecular dynamics simulations were carried out. Clustering analysis was done to study relevant conformations of the systems. Differences in the global conformation of the enzyme between systems with R or S enantiomers were not observed. Interestingly however, orientation of the partially buried side chain for Ile285 was affected. This could explain the increased enantiomeric ratio observed with the substrate ester (R)-1-methylpentyl propanoate due to an improved (R)-pentan-2-ol/enzyme interaction.
Mutations in the stereospecificity pocket and at the entrance of the active site of Candida antarctica lipase B enhancing enzyme enantioselectivity
Marton,Leonard-Nevers,Syren,Bauer,Lamare,Hult,Tranc,Graber
, p. 11 - 17 (2010)
Two different parts of Candida antarctica lipase B (stereospecificity pocket at the bottom of the active site and hydrophobic tunnel leading to the active site) were redesigned by single- or double-point mutations, in order to better control and improve enzyme enantioselectivity toward secondary alcohols. Single-point isosteric mutations of Ser47 and Thr42 situated in the stereospecificity pocket gave rise to variants with doubled enantioselectivity toward pentan-2-ol, in solid/gas reactor. Besides, the width and shape of the hydrophobic tunnel leading to the active site was modified by producing the following single-point mutants: Ile189Ala, Leu278Val and Ala282Leu. For each of these variants a significant modification of enantioselectivity was observed compared to wild-type enzyme, indicating that discrimination of the enantiomers by the enzyme could also arise from their different accessibilities from the enzyme surface to the catalytic site.
Enzymatic kinetic resolution of aliphatic sec-alcohols by LipG9, a metagenomic lipase
Bandeira, Pamela T.,Alnoch, Robson C.,De Oliveira, Alfredo R.M.,De Souza, Emanuel M.,De O.P., Fábio,Krieger, Nadia,Piovan, Leandro
, p. 58 - 63 (2016/01/30)
Bioprospection for new enantioselective enzymes for application in organic synthesis is a prominent area of investigation in biocatalysis. In this context, here we present the evaluation of an immobilized lipase isolated from a metagenomic library (LipG9) for the enzymatic kinetic resolution (EKR) of aliphatic sec-alcohols, which are still challenging substrates, since low enantioselectivity values are usually observed for these resolutions. LipG9 was successfully employed in EKR of aliphatic alcohols, which were resolved with satisfactory conversions (19-59%) and enantiomeric excesses for alcohols (26-88%) and esters (30-96%) by transesterification reactions, demonstrating that its performance is equal to or better than commercially available enzymes for the same reaction.
An extremely efficient and green method for the acylation of secondary alcohols, phenols and naphthols with a deep eutectic solvent as the catalyst
Nguyen, Hai Truong,Tran, Phuong Hoang
, p. 98365 - 98368 (2016/10/31)
The typical deep eutectic solvent [CholineCl][ZnCl2]3, easily prepared from choline chloride and zinc chloride, is green and useful for the acylation of secondary alcohols, phenols, and naphthols with acid anhydrides. Its efficiency allows the acylation of sterically hindered secondary alcohols and acid anhydrides to proceed in high yield under mild condition. The catalyst is cheap, easy to handle, conveniently synthesized in a single step, and recyclable for several times without significant loss of catalytic activity.
Structure-function correlation in lipase catalysed esterification reactions of short and medium carbon chain length alcohols and acids
Divakar, Soundar
, p. 1919 - 1922 (2007/10/03)
An attempt has been made to correlate the carbon chain lengths of acids and alcohols to the extent of esterification in the Rhizomucor miehei lipase catalyzed esterification reactions involving acids of carbon chain length C2-C5 and alcohols of carbon chain length C1-C8.
