Kinetic Study on the Enzymatic Resolution of Homophenylalanine Ester Using Ionic Liquids

Zhao, Hua; Luo, Robert G.; Malhotra, Sanjay V.

doi:10.1021/bp025721b

Cited by 47 publications

(28 citation statements)

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“…[16][17][18][19] AAILs have been employed as chiral solvents or reactants for dissolution and stabilization of cellulose, nucleic acids, carbohydrates and other species of primary biological importance. [20][21][22][23][24][25] On the theoretical front, molecular dynamics (MD) simulations on the ILs composed of deprotonated amino acid anions and choline cation revealed that their formation is facilitated through proton transfer involving the hydrogen bond effectively neutralizing cation and anion. 26 Fileti and coworkers 27 A molecular level understanding of noncovalent interactions encompassing hydrogen bonding, steric repulsion, aromatic ring stacking and electrostatic interactions should prove useful 5 for designing of task specific ILs.…”

Section: Introductionmentioning

confidence: 99%

Electronic Structure, NMR, Spin–Spin Coupling, and Noncovalent Interactions in Aromatic Amino Acid Based Ionic Liquids

Rao

Gejji

2016

J. Phys. Chem. A

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Noncovalent interactions accompanying phenylalanine (Phe), tryptophan (Trp), and tyrosine (Tyr) amino acids based ionic liquids (AAILs) composed of 1-methyl-3-butyl-imidazole and its methyl-substituted derivative as cations have been analyzed employing the dispersion corrected density functional theory. It has been shown that cation-anion binding in these bioionic ILs is primarily facilitated through hydrogen bonding in addition to lp---π and CH---π interactions those arising from aromatic moieties which can be probed through (1)H and (13)C NMR spectra calculated from the gauge independent atomic orbital method. Characteristic NMR spin-spin coupling constants across hydrogen bonds of ion pair structures viz., Fermi contact, spin-orbit and spin-dipole terms show strong dependence on mutual orientation of cation with the amino acid anion. The spin-spin coupling mechanism transmits spin polarization via electric field effect originating from lp---π interactions whereas the electron delocalization from lone pair on the carbonyl oxygen to antibonding C-H orbital is facilitated by hydrogen bonding. It has been demonstrated that indirect spin-spin coupling constants across the hydrogen bonds correlate linearly with hydrogen bond distances. The binding energies and dissected nucleus independent chemical shifts (NICS) document mutual reduction of aromaticity of hydrogen bonded ion pairs consequent to localization of π-character. Moreover the nature and type of such noncovalent interactions governing the in-plane and out-of-plane NICS components provide a measure of diatropic and paratropic currents for the aromatic rings of varying size in AAILs. Besides the direction of frequency shifts of characteristic C═O and NH stretching vibrations in the calculated vibrational spectra has been rationalized.

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Section: Introductionmentioning

confidence: 99%

Electronic Structure, NMR, Spin–Spin Coupling, and Noncovalent Interactions in Aromatic Amino Acid Based Ionic Liquids

Rao

Gejji

2016

J. Phys. Chem. A

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“…The kinetic resolution of amino acids is influenced by solvent nature, polarity, and concentration. 17 It was observed that improved enzyme activity could be obtained by adjusting these solvent parameters. A systematic study with variation in ionic liquid concentration in the reaction mixture showed that best results in terms of enantiomeric excess and product yields are obtained with 15% ionic liquid solution in water.…”

Section: Resultsmentioning

confidence: 99%

“…15,16 A report in the literature showed that organic solvents have significant effect on the activity and enantioselectivity of protease in hydrolyzing esters or peptides. 4 However, based on our earlier successful studies in ionic liquids 17,18 and with the foreseeable advantages and goal of finding an environmentally friendly, i.e., ''green'' medium to substitute organic solvents, we investigated the resolution of a series of amino acid esters using porcine pancreas lipase (PPL). In this article, we report the results of this study.…”

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confidence: 99%

Enantioseparation of the esters of α-N-acetyl amino acids by lipase in ionic liquid

Malhotra

Zhao

2005

Chirality

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Chiral alpha-amino acids have been obtained via enzymatic resolution in ionic liquid medium. The acetyl esters of a series of amino acids were separated by enzyme porcine pancreas lipase (PPL) in an aqueous solution of N-ethyl pyridinium trifluoroacetate, [EtPy]+ [CF3OO]-. A comparative study with organic solvent acetonitrile shows that the ionic liquids provide a better medium for enzymatic resolution.

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“…The solvent optimization done with N-acetyl-DL-homophenylalanine ethyl ester 1 (Fig. (1 [21]. When the reaction was studied in acetonitrile, lower ee values were observed at higher concentrations of acetonitrile mainly because of the inhibition of the enzyme activity by acetonitrile.…”

Section: Enzyme Mediated Enantioselective Reactions In Ionic Liquidsmentioning

confidence: 99%

Enzyme Mediated Reactions in Ionic Liquids

Harjani¹,

Naik²,

Nara³

et al. 2007

COS

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Kinetic Study on the Enzymatic Resolution of Homophenylalanine Ester Using Ionic Liquids

Cited by 47 publications

References 10 publications

Electronic Structure, NMR, Spin–Spin Coupling, and Noncovalent Interactions in Aromatic Amino Acid Based Ionic Liquids

Electronic Structure, NMR, Spin–Spin Coupling, and Noncovalent Interactions in Aromatic Amino Acid Based Ionic Liquids

Enantioseparation of the esters of α-N-acetyl amino acids by lipase in ionic liquid

Enzyme Mediated Reactions in Ionic Liquids

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