Chiral sensors for determining the absolute configurations of α-amino acid derivatives

2018 ◽  
Vol 16 (37) ◽  
pp. 8311-8317 ◽  
Author(s):  
Zhongxiang Chen ◽  
Hongjun Fan ◽  
Shiwei Yang ◽  
Guangling Bian ◽  
Ling Song

Two simple 1H NMR tests give the absolute configurations of α-amino acids.

2021 ◽  
Vol 10 ◽  
Author(s):  
Catherine Deborde ◽  
Blandine Madji Hounoum ◽  
Annick Moing ◽  
Mickaël Maucourt ◽  
Daniel Jacob ◽  
...  

Abstract The long-term effect of a plant (P)-based diet was assessed by proton nuclear magnetic resonance (1H-NMR) metabolomics in rainbow trout fed a marine fish meal (FM)–fish oil (FO) diet (M), a P-based diet and a control commercial-like diet (C) starting with the first feeding. Growth performances were not heavily altered by long-term feeding on the P-based diet. An 1H-NMR metabolomic analysis of the feed revealed significantly different soluble chemical compound profiles between the diets. A set of soluble chemical compounds was found to be specific either to the P-based diet or to the M diet. Pterin, a biomarker of plant feedstuffs, was identified both in the P-based diet and in the plasma of fish fed the P-based diet. 1H-NMR metabolomic analysis on fish plasma and liver and muscle tissues at 6 and 48 h post feeding revealed significantly different profiles between the P-based diet and the M diet, while the C diet showed intermediate results. A higher amino acid content was found in the plasma of fish fed the P-based diet compared with the M diet after 48 h, suggesting either a delayed delivery of the amino acids or a lower amino acid utilisation in the P-based diet. This was associated with an accumulation of essential amino acids and the depletion of glutamine in the muscle, together with an accumulation of choline in the liver. Combined with an anticipated absorption of methionine and lysine supplemented in free form, the present results suggest an imbalanced essential amino acid supply for protein metabolism in the muscle and for specific functions of the liver.


2005 ◽  
Vol 2005 (10) ◽  
pp. 640-642 ◽  
Author(s):  
Ying Liu ◽  
Liang Zhao ◽  
Liang Liu ◽  
Lin-Yi Wei ◽  
Lu-Hua Lai

Amino acid derivatives of a modified indole-3-acetic acid have been synthesised. Fourteen new dipeptide-like compounds 3–4 were obtained and their structures were elucidated based on the IR, 1H NMR, MS spectra.


2016 ◽  
Vol 7 (2) ◽  
pp. 1104-1108 ◽  
Author(s):  
Jun-Xia Guo ◽  
Ting Zhou ◽  
Bin Xu ◽  
Shou-Fei Zhu ◽  
Qi-Lin Zhou

A new highly enantioselective route to α-alkenyl α-amino acid derivatives using a N–H insertion reaction of vinyldiazoacetates and tert-butyl carbamate cooperatively catalyzed by achiral dirhodium(ii) carboxylates and chiral spiro phosphoric acids was developed.


2005 ◽  
Vol 58 (11) ◽  
pp. 778 ◽  
Author(s):  
Andrew B. Hughes ◽  
Brad E. Sleebs

N-Methyl β-amino acids are potentially useful amino acid derivatives for incorporation in lead peptide therapeutics. The syntheses of five such compounds are presented. Their synthesis via 6-oxazinanones was low yielding. Alternatively, reductive cleavage of a 5-oxazolidinone gave the N-methyl α-amino acid, which was then homologated via an Arndt–Eistert procedure in high yield to give the N-methyl β-amino acid.


Author(s):  
L.A. Truzina ◽  

The highest percentage of protein is observed at the beginning of the Bud formation phase, especially in the leaves. The amino acid composition of the protein does not change, but depending on the phase of development and analyze parts of the plant, the absolute content of their different.


1983 ◽  
Vol 38 (5-6) ◽  
pp. 359-368 ◽  
Author(s):  
Fritz Thümmler ◽  
Wolfhart Rüdiger ◽  
Edmund Cmiel ◽  
Siegfried Schneider

Chromopeptides were prepared by pepsin digestion of C-phycocyanin isolated from the cyano­bacterium Spirulina maxima and of phytochrome isolated from seedlings of Avena sativa L. The chromopeptides were characterized by amino acid analysis. The ZZZ configurated chromophore of the phycocyanin peptide was transformed into its ZZE configurated isomer by the method of Falk et al. (Mh. Chemie 111, 159- 175, 1980) which had previously been applied to biliverdins. The 500 MHz 1HNMR spectrum of the ZZE configurated chromopeptides confirmed that its chromophore has the 15 E configuration. Irradiation yielded the ZZZ configurated isomer for which the 1H NMR spectrum was also recorded. Native phytochrome was irradiated at 660 nm to yield the maximum amount of the Pfr from (about 75% of total phytochrome). By digestion in the dark the previously described Pfr chromopeptide was obtained. The 500 MHz 1H NMR spectrum was compared with that of the ZZE phycocyanin peptide. It confirmed the 15 E con­figuration of the Pfr chromopeptide. Irradiation yielded the 15 Z configurated Pr chromopeptide. Comparison of the high resolution 1HNMR spectra of Pfr and Pr chromopeptides revealed that not only the chromophore resonances but also those of some amino acids are changed by the Pfr → Pr chromopeptide phototransformation. The results are discussed in terms of chromophore amino acid interaction.


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