5699-54-7Relevant articles and documents
Resolution of α/β-amino acids by enantioselective penicillin G acylase from Achromobacter sp.
Grulich, Michal,Brezovsky, Jan,?těpánek, Václav,Palyzová, Andrea,Kyslíková, Eva,Kyslík, Pavel
, p. 240 - 247 (2015/10/28)
Penicillin G acylases (PGAs) are enantioselective enzymes catalyzing a hydrolysis of stable amide bond in a broad spectrum of substrates. Among them, derivatives of α- and β-amino acids represent a class of compounds with high application potential. PGAEc from Escherichia coli and PGAA from Achromobacter sp. CCM 4824 were used to catalyze enantioselective hydrolyses of seven selected N-phenylacetylated α/β-amino acid racemates. The PGAA showed higher stereoselectivity for enantiomers of N-PhAc-β-homoleucine, N-PhAc-α-tert-leucine and N-PhAc-β-leucine. To study the mechanism of enantiodiscrimination on molecular level, we have constructed a homology model of PGAA that was used in molecular docking experiments with the same substrates. In-silico experiments successfully reproduced the data from experimental enzymatic resolutions confirming validity of employed modeling protocol. We employed this protocol to evaluate enantiopreference of PGAA towards seven new substrates with application potential. For five of them, high enantioselectivity of PGAA was predicted.
METHOD FOR OBTAINING OPTICALLY PURE AMINO ACIDS
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Page/Page column 10-11, (2012/02/14)
This invention relates to a method for obtaining optically pure amino acids, including optical resolution and optical conversion. This method significantly shortens the time taken for optical transformation, and enables the repeated use of an organic solution containing a enantioselective receptor, to thereby obtain optically pure amino acids in a simple and remarkably efficient manner, and to enable the very economical mass production of optically pure amino acids.
Kinetic and NMR spectroscopic studies of chiral mixed sodium/lithium amides used for the deprotonation of cyclohexene oxide
Sott, Richard,Granander, Johan,Williamson, Carl,Hilmersson, Goeran
, p. 4785 - 4792 (2007/10/03)
The mixed-metal complex formed from n-butylsodium, n-butyllithium, and a chiral amino ether has been studied by NMR spectroscopy. Three different mixed-metal amides were used as chiral bases for the deprotonation of cyclohexene oxide. The selectivity and initial rate of reaction were compared for sodium-amido ethers, lithium-amido ethers, and mixtures of sodium and lithiumamido ethers in diethyl ether and tetrahydrofuran, respectively. The mixed sodium/lithium amides are more reactive than the single sodium and lithium amides, whereas the stereoselectivities are higher when lithium amides are used. The alkali-metal/γ-amido ethers exhibit both higher initial reaction rates and stereoselectivities than their β-amido ether analogues. NMR spectroscopic studies of mixtures of n-butylsodium (nBuNa), n-butyllithium (nBuLi), and the γ-amino ethers in diethyl ether show the exclusive formation of dimeric mixed-metal amides. In diethyl ether, the lithium atom of the mixed-metal amide is internally coordinated and the sodium atom is exposed to solvent; however, in tetrahydrofuran, both metals are internally coordinated.
