2-氨基-4-甲基戊酰胺 在
D-amidase from bacterium Variovorax paradoxus 作用下,
以
various solvent(s) 为溶剂,
生成 D-亮氨酸
参考文献:
名称:
Screening for Amidases: Isolation and Characterization of a Novel D-Amidase from Variovorax paradoxus
摘要:
Using racemic tert-leucine amide as sole nitrogen source in minimal medium, 162 strains were isolated by enrichment techniques and shown to contain amidase activity. Among these isolates three D-amidase producers were found and identified as Variovorax paradoxus (two strains) and Klebsiella spec. The D-amidase from Variovorax paradoxus was purified to homogeneity by three chromatographic steps. With DL-Tle-amide as substrate Michaelis-Menten kinetics were observed with a K-M of 0.74 mM, a K-1 of 640 mM and a V-max of 1.4 U/mg. The amidase has a broad pH-optimum between 7 and 9.5 and a temperature optimum at 47 - 49 degreesC. The amidase hydrolyzed amino acid amides as well as carboxamides and 2-hydroxy acid amides. The stereoselectivity of the reaction was variable, however. Hydrolyzing DL-Tle-amide the enantiomeric ratio E was >200 resulting in D-Tle with an ee of >99% and up to 47% conversion. Similar results were obtained with DL-Leu-amide and DL-Val-amide while DL-Phe-amide was hydrolyzed with an enantiomeric ratio E of only 5.
N-o-Nitrophenylsulfenylamino acid amides of glycine, alanine (DL and L), leucine (DL and L), methionine (DL), phenylalanine (DL and L), and proline (L) were dehydrated in POCl3-pyridine. The N-protected α-amino-nitriles obtained were treated with anhydrous HCl affording the corresponding α-aminonitrile hydrochlorides. The optical purity of the L-α-aminonitriles was well retained.
Peptide ligation by chemoselective aminonitrile coupling in water
作者:Pierre Canavelli、Saidul Islam、Matthew W. Powner
DOI:10.1038/s41586-019-1371-4
日期:2019.7
N-to-C peptide ligation. Our model unites prebiotic aminonitrile synthesis and biological α-peptides, suggesting that short N-acyl peptide nitriles were plausible substrates during early evolution.Prebiotic peptide formation is achieved through chemoselective, high-yielding ligation of α-aminonitriles in water, showing selectivity for α-peptide coupling and tolerance of all proteinogenic amino acid residues
The present invention relates to compounds of Formula (I),
or a form thereof, wherein ring A, R
1
, R
2
, R
3
, R
3
′, L, W, and V are as defined herein, useful as FLAP modulators. The invention also relates to pharmaceutical compositions comprising compounds of Formula (I). Methods of making and using the compounds of Formula (I) are also within the scope of the invention
enantioselective ring-opening desymmetrization of meso-aziridines with isocyanides was achieved in the presence of a chiral N,N′-dioxide/Mg(OTf)2 complex. The in situ generated chiral 1,4-zwitterionic intermediates were successfully trapped by intramolecular oxygen- and carbon-based nucleophiles or exogenous H2O and TMSN3, enabling a collective synthesis of various chiral vicinal amino-oxazoles, spiroindolines,
Application of aminoacylase I to the enantioselective resolution of α-amino acid esters and amides
作者:Maxim I Youshko、Luuk M van Langen、Roger A Sheldon、Vytas K Švedas
DOI:10.1016/j.tetasy.2004.05.018
日期:2004.6
Aminoacylase I from Aspergillus melleus, a readily available and inexpensive enzyme mainly used in the industrial production of enantiopure l-amino acids from their N-acetyl derivatives, is shown to hydrolyze the esters and amides of natural and non-natural amino acids with high enantioselectivity (for the ester hydrolysis, E is up to 76, in case of amides E >300). The reaction rates of amide and ester