Full metadata record
DC Field | Value | Language |
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dc.contributor.author | 김관묵 | - |
dc.date.accessioned | 2016-11-30T02:11:30Z | - |
dc.date.available | 2016-11-30T02:11:30Z | - |
dc.date.issued | 2008 | - |
dc.identifier.issn | 0947-6539 | - |
dc.identifier.other | OAK-5225 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/232908 | - |
dc.description.abstract | (S)-2-Hydroxy-2′-(3-phenyl-uryl-benzyl)-1,1′-binaphthyl-3- carboxaldehyde (1) forms Schiff bases with a wide range of nonderivatized amino acids, including unnatural ones. Multiple hydrogen bonds, including resonance-assisted ones, fix the whole orientation of the imine and provoke structural rigidity around the imine C=N bond. Due to the structural difference and the increase in acidity of the a proton of the amino acid, the imine formed with an L-amino acid (1-L-aa) is converted into the imine of the D-amino acid (1-D-aa), with a D/L ratio of more than 10 for most amino acids at equilibrium. N-terminal amino acids in dipeptides are also predominantly epimerized to the D form upon imine formation with 1. Density functional theory calculations show that 1-D-Ala is more stable than 1-L-Ala by 1.64 kcal mol-1, a value that is in qualitative agreement with the experimental result. Deuterium exchange of the a proton of alanine in the imine form was studied by 1H NMR spectroscopy and the results support a stepwise mechanism in the L-into-D conversion rather than a concerted one; that is, deprotonation and protonation take place in a sequential manner. The deprotonation rate of L-Ala is approximately 16 times faster than that of D-Ala. The protonation step, however, appears to favor L-amino acid production, which prevents a much higher predominance of the D form in the imine. Receptor 1 and the predominantly D-form amino acid can be recovered from the imine by simple extraction under acidic conditions. Hence, 1 is a useful auxiliary to produce D-amino acids of industrial interest by the conversion of naturally occurring L-amino acids or relatively easily obtainable racemic amino acids. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA. | - |
dc.language | English | - |
dc.title | Stereoconversion of amino acids and peptides in uryl-pendant binol schiff bases | - |
dc.type | Article | - |
dc.relation.issue | 32 | - |
dc.relation.volume | 14 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.startpage | 9935 | - |
dc.relation.lastpage | 9942 | - |
dc.relation.journaltitle | Chemistry - A European Journal | - |
dc.identifier.doi | 10.1002/chem.200801036 | - |
dc.identifier.wosid | WOS:000261074800017 | - |
dc.identifier.scopusid | 2-s2.0-55449112158 | - |
dc.author.google | Park H. | - |
dc.author.google | Nandhakumar R. | - |
dc.author.google | Hong J. | - |
dc.author.google | Ham S. | - |
dc.author.google | Chin J. | - |
dc.author.google | Kim K.M. | - |
dc.contributor.scopusid | 김관묵(35484385500) | - |
dc.date.modifydate | 20230208104137 | - |