Enzymic synthesis design and enzymic synthesis of aspartame
作者:Ivanka B. Stoineva、Boris P. Galunsky、Valentin S. Lozanov、Ivailo P. Ivanov、Dimiter D. Petkov
DOI:10.1016/s0040-4020(01)88207-7
日期:1992.1
An enzymicsynthesis of aspartame (H-Asp-Phe-OMe) has been designed and realized based on the structure-activity study of thermolysin and penicillin amidase hydrolysis of its p-substituted phenylacetyl derivatives. These compounds meet the structural and energetic requirements of two enzymic binding sites The peptide sweetener has been prepared by thermolysin - catalyzed condensation of the p-substituted
Method for purifying N-benzyloxycarbonyl aspartic acid
申请人:PPG INDUSTRIES, INC.
公开号:EP0072015A1
公开(公告)日:1983-02-16
N-benzyloxycarbonyl aspartic acid containing minor contaminating amounts of N-benzyloxycarbonyl aspartyl aspartic acid is purified by subjecting the impure material to alkaline hydrolysis at a pH of at least 10 and at temperatures of from 20°C. to 100°C., preferably 65°C. to 85°C., for a time sufficient to hydrolyze substantially all of the N-benzyloxycarbonyl aspartyl aspartic acid impurity therein. N-benzyloxycarbonyl aspartic acid containing less than 0.2 weight percent of the impurity can be obtained by such treatment.
Verfahren zur Herstellung von Dipeptid-Additionsverbindungen und den daraus freigesetzten Dipeptiden
申请人:HOECHST AKTIENGESELLSCHAFT
公开号:EP0241864A2
公开(公告)日:1987-10-21
Bei der enzymatischen Verknüpfung von D-,L-Phenylalaninalkylester oder L-Phenylalaninalkylester mit einer N-geschützten L-Asparaginsäure können eine Phenoxyacetyl-, Phenoxypropionyl- oder Phenylacetylgruppe als Aminoschutzgruppe verwendet werden.
Preparation of d-amino acids by enzymatic kinetic resolution using a mutant of penicillin-G acylase from E. coli
作者:Chiara Carboni、Hans G.T. Kierkels、Lucia Gardossi、Kamil Tamiola、Dick B. Janssen、Peter J.L.M. Quaedflieg
DOI:10.1016/j.tetasy.2005.12.023
日期:2006.1
We have demonstrated for the first time that D-glutamine (D-Gln) and D-glutamic acid (D-Glu) can be efficiently obtained in high ee (97% and 90%, respectively) by enzymatic kinetic resolution of D,L-Gln and D,L-Glu. This was achieved by enantioselective conversion of the L-enantiomers to their N-phenylacetyl derivatives in aqueous solution, using a mutant of penicillin-G acylase (PGA) from E coli and phenylacetic acid methylester as the acyl donor. Kinetic modeling studies suggest that the high ee values obtained are both due to a strong enantiopreference for the L-amino acid in the deacylation step of the covalent enzyme intermediate, as well as to completeness of conversion that is transiently obtained as a result of the distinct preference of the mutant PGA for phenylacetic acid methylester over the N-phenylacetyl-L-amino acid product. For the other amino acids tested (Asn, Asp, and Ser), the highest ee values that were obtained for the remaining D-enantiomer are moderate (50-80%)because of lower enantioselectivity in the enzyme deacylation step and due to less complete conversion of the L-amino acid caused by competition for the active site between the acyl donor and the N-phenylacetyl-L-amino acid that is produced. The results demonstrate that the mutated PGA has great potential for the production of optically active D-amino acids by kinetic resolution. (c) 2006 Published by Elsevier Ltd.