116644-59-8Relevant academic research and scientific papers
The effect of the migrating group structure on enantioselectivity in lipase-catalyzed kinetic resolution?of?1-phenylethanol
Melais, Nedjma,Aribi-Zouioueche, Louisa,Riant, Olivier
, p. 971 - 977 (2016)
We have studied the effects of the acyl moiety on the enantioselectivity of three lipases: Candida antarctica B, Pseudomonas cepacia and Candida cylindracea, frequently used in kinetic resolutions by acylation or hydrolysis. The size of the acyl group was examined using various enol esters during the transesterification of 1-phenylethanol and the hydrolysis of the corresponding phenylethylesters. C. antarctica-B lipase showed the highest selectivity in the transesterification of 1-phenylethanol with isopropenyl and vinyl acetate, vinyl decanoate, vinyl laurate, (E?>?200). The esters 1-phenyl -ethyl-acetate, decanoate and laurate are also hydrolyzed with high selectivities (E?>?150) with CAL-B. The results can be correlated to the three-dimensional form of each lipase. The effect of the migrating group on the reactivity and selectivity of the lipases are discussed for both reactions.
Reversible activity changes of a lipid-coated lipase for enantioselective esterification in supercritical fluoroform
Mori,Funasaki,Kobayashi,Okahata
, p. 1832 - 1833 (2001)
Enzymatic activity of a lipid-coated lipase for enantioselective esterification of (R)-1-phenylethanol in supercritical fluoroform can be reversibly controlled by changing pressure or temperature that reflects changes of dielectric constant.
A Lipid-Coated Lipase as an Enantioselective Ester Synthesis Catalyst in Homogeneous Organic Solvents
Okahata, Yoshio,Fujimoto, Yoshitaka,Ijiro, Kuniharu
, p. 2244 - 2250 (1995)
A lipid-coated lipase was prepared, in which hydrophilic head groups of lipids interact with the hydrophilic surface of the enzyme and lipophilic alkyl chains extend away from its surface and solubilize the enzyme in hydrophobic organic solvents.Enantiose
Resin glycoside constituents of Ipomoea pes-caprae (beach morning glory)
Tao, Hongwen,Hao, Xiaojiang,Liu, Jinggen,Ding, Jian,Fang, Yuchun,Gu, Qianqun,Zhu, Weiming
, p. 1998 - 2003 (2008)
Eight new resin glycosides, pescapreins X-XVII (1-8), were isolated from a lipophilic fraction of an ethanol extract of the entire plant of beach morning glory, Ipomoea pes-caprae. Their structures were elucidated by spectroscopic data analysis and by chemical transformation. These compounds were evaluated biologically in terms of cancer cell line cytotoxicity, antibacterial and antifungal activity, and effects on the μ-opioid receptor.
Acid zeolites as alcohol racemization catalysts: Screening and application in biphasic dynamic kinetic resolution
Wuyts,De Temmerman,De Vos,Jacobs
, p. 386 - 397 (2005)
Acid zeolites were screened as heterogeneous catalysts for racemization of benzylic alcohols. The most promising zeolites appeared to be H-Beta zeolites, for which the optimal reaction conditions were studied in further detail. The zeolite performance was
Two Approaches for CAL-B-Catalyzed Enantioselective Deacylation of a Set of α-Phenyl Ethyl Esters: Organic Solvent with Sodium Carbonate and Micro-aqueous Medium
Razi, Samra,Zeror, Saoussen,Merabet-Khelassi, Mounia,Kolodziej, Emilie,Toffano, Martial,Aribi-Zouioueche, Louisa
, p. 2603 - 2611 (2021/01/15)
Herein, we report an efficient enantioselective cleavage of the acyl- moiety of a set of α- phenyl ethyl esters with different chain-lengths catalyzed by lipase B from Candida antarctica (CAL-B) by comparing two reactional approaches: anhydrous media with sodium carbonates and micro-aqueous medium. The deacylation is performed in organic solvent, in the presence of Na2CO3 in the first case, and by addition of a drop of phosphate buffer solution pH 7 in the second. The results show the high efficiency of the deacylation in the presence of the sodium carbonate for the enzymatic resolution of all the esters and that in term of reactivity (31% ≤ conv ≤ 50%) and selectivity (E > 200). While, during the hydrolysis in micro-aqueous media, the conversion is strongly affected by the length of the acyl-chain side, the conversion decreases from conv = 50% with the 1-phenylethyl acetate 1a to conv = 19% with 1-phenyethyl dodecanoate 6a, and this, even if the selectivity remains high (E > 89). In both conditions, the lipase CAL-B shows a high enantioselectivities in favor of (R)-1-phenyl ethanol enantiomer (conv > 45%, E > 200) but the reactivity is modulated by the form and the size of the acyl-chain side. Graphic Abstract: [Figure not available: see fulltext.].
Easy and simple SiO2 immobilization of lipozyme CaLB-L: Its use as a catalyst in acylation reactions and comparison with other lipases
Mittersteiner, Mateus,Machado, Tayani M.,De Jesus, Paulo Cesar,Brondani, Patrícia B.,Scharf, Dilamara R.,Wendhausen, Renato
, p. 1185 - 1192 (2017/06/07)
In this study, lipase from Candida antarctica B (Lipozyme CaLB-L) was successfully immobilized on SiO2 through adsorption and used to obtain (R)-(+)-esters derived from (R,S)-1-phenylethanol. The new immobilized enzyme was compared with commercially immobilized lipases (Novozyme 435, Lipozyme 435 and Pseudomonas cepacia (PSC-II and PSD-I)). Lipozyme CaLB-L adsorbed onto SiO2 was found to be a good catalyst and, under optimal conditions, esters could be obtained with conversion 44percent, enantiomeric excess of product (eep) > 99percent, enantiomeric excess of substract (ees) 77percent and enantiomeric ratio (E) > 200. The lipase maintained enantioselectivity under adverse conditions, such as in organic solvents, with an excess of substrate and at different temperatures. The immobilized lipase could be reused five times with no significant loss of the activity.
Low-temperature enzymatic hydrolysis resolution in mini-emulsion media
Louren?o, Nuno M.T.,Matias, Sara C.,Altas, Margarida C.,Fonseca, Luis P.
, p. 810 - 816 (2015/03/31)
A low-temperature mini-emulsion medium for the enzymatic resolution of 1-phenylethanol is described for the first time. The enzymatic hydrolysis resolution of 1-phenylethyl esters with different chain-lengths in the presence of Candida antarctica lipase B in mini-emulsion media was shown to be significantly controlled by temperature. In this system, the direct effect of temperature on the mini-emulsion size was observed. For the longer 1-phenylethyl ester, 1-phenylethyl dodecanoate, the enzymatic resolution was promoted exclusively at low temperatures. The preparative mini-emulsion enzymatic reaction of 1-phenylethyl dodecanoate at 4°C afforded the isolation of (R)-phenylethanol with a yield of 36 % with an ee of 99 %. (S)-Phenylethanol was isolated with a 51 % yield with an ee of 79 %.
A zeolite-enzyme combination for biphasic dynamic kinetic resolution of benzylic alcohols.
Wuyts, Stijn,De Temmerman, Karolien,De Vos, Dirk,Jacobs, Pierre
, p. 1928 - 1929 (2007/10/03)
Acid zeolites like H-Beta are efficient heterogeneous catalysts for racemization of benzylic alcohols in water; by combination of the racemization with an enzymatic kinetic resolution in a two-phase system, enantiomerically pure esters were obtained in hi
Continuous Flow Enzymatic Kinetic Resolution and Enantiomer Separation using Ionic Liquid/Supercritical Carbon Dioxide Media
Reetz, Manfred T.,Wiesenhoefer, Wolfgang,Francio, Giancarlo,Leitner, Walter
, p. 1221 - 1228 (2007/10/03)
The combination of kinetic resolution in ionic liquids (IL) and selective extraction with supercritical carbon dioxide (scCO2) provides a new approach for the separation of enantiomers as exemplified by the lipase-catalyzed esterification of chiral secondary alcohols. Excellent enantioselectivities are achieved upon conversion of alcohols 1a-e to the corresponding acetates 4a-e or laureates 5a-e using various modifications of the lipase from Candida antarctica (CaL-B) in imidazolium-based ionic liquids. The anion of the ionic liquid has a significant influence on the performance of the bio-catalyst with bis(trifluoromethanesulfonamide) [BTA] giving the best results. The acetates 4a-e can be extracted from the reaction mixture preferentially over the alcohols 1a-e with scCO2 under certain conditions, but preparatively useful selectivities would require advanced multi-step extraction procedures. In contrast, efficient separation is possible with relatively simple equipment if alcohols 1a-e are extracted preferentially from their corresponding laureates 5a-e. A "green" continuous process for the resolution of racemic alcohols without the use of organic solvents was devised on the basis of these findings.
