The reaction of glyoxylic acid with ammonia revisited
摘要:
Upon addition of ammonia or an alkylamine to glyoxylic acid an ammonium derivative of glyoxylic acid precipitates quantitatively. With the use of solid-state C-13 and N-15 NMR spectroscopy, it is shown that adducts of glyoxylic acid and ammonia or the alkylamine are obtained. These compounds are not stable in aqueous solution. The compositions of the aqueous solutions have been investigated by H-1, C-13, N-15, and O-17 NMR. Under basic conditions hexahydro-s-triazine-2,4,6-tricarboxylate is the predominant species in a solution of the adduct of ammonia and glyoxylic acid, whereas upon acidification (pH < 6) glyoxylate is the only organic species. In a basic solution of the adduct of ethylamine and glyoxylic acid N-ethylirainoacetate is the only species. The N-methyl adduct shows an intermediate behavior: both the hexahydrotriazine and the imine are observed. Under acidic conditions deamination to glyoxylate always occurs. Intermediates in the reaction of glyoxylic acid and ammonia could be detected with H-1 NMR, when the reaction was performed with an excess of ammonia. The mechanism of these reactions is discussed.
[EN] DERMAL COMPOSITIONS CONTAINING UNNATURAL HYGROSCOPIC AMINO ACIDS<br/>[FR] COMPOSITIONS DERMATOLOGIQUES CONTENANT DES AMINOACIDES HYGROSCOPIQUES NON NATURELS
申请人:MEDPHARM LTD
公开号:WO2014072747A1
公开(公告)日:2014-05-15
Unnatural, hygroscopic amino acids are useful to enhance the moisture retention and uptake properties of skin. In particular, such amino acids are N-hydroxyserine, N- hydroxyglycine, L-homoserine,alpha-hydroxyglycine, 2-(aminooxy) -2-hydroxyacetic acid, 2-hydroxy-2-(hydroxyamino) acetic acid, 2- (aininooxy)acetic acid, and combinations thereof.
Hf(OTf)<sub>4</sub>-Doped Me<sub>3</sub>SiCl-Catalyzed Aminomethylation of Arenes with <i>N</i>,<i>O</i>-Acetals: Facile Approach to Non-Natural Aromatic Amino Acid Precursors
The authors demonstrated a Hf(OTf)4-Me3SiCl-system-catalyzed aminomethylation of an aromatic compound, such as a heterocycle or an electron-rich arene, with several new types of N,O-acetals having both a cyano group and a cyclic amino moiety. This method permits the facile synthesis of artificial aromatic amino acid precursors.
Catalytic amino acid production from biomass-derived intermediates
作者:Weiping Deng、Yunzhu Wang、Sui Zhang、Krishna M. Gupta、Max J. Hülsey、Hiroyuki Asakura、Lingmei Liu、Yu Han、Eric M. Karp、Gregg T. Beckham、Paul J. Dyson、Jianwen Jiang、Tsunehiro Tanaka、Ye Wang、Ning Yan
DOI:10.1073/pnas.1800272115
日期:2018.5.15
reversible enhancement effect of NH3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing
Nitrosation and analysis of amino acid derivatives by isocratic HPLC
作者:Songül Ulusoy、Halil Ibrahim Ulusoy、Daniel Pleissner、Niels Thomas Eriksen
DOI:10.1039/c5ra25854e
日期:——
The objective of this study was to characterize the nitrosation of the classical amino acids by N2O3. Nitrosation of amino acids results in the formation of mainly α-hydroxy-acids that are suitable for isocratic HPLC analysis and subsequent quantification of amino acids in biological samples. The method is particularly suitable for detection of amino acids in e.g. fermentation media as the α-hydroxy-acids
这项研究的目的是表征N 2 O 3对经典氨基酸的亚硝化作用。氨基酸亚硝化会形成主要为α-羟基的酸,这些酸适用于等度HPLC分析以及随后对生物样品中氨基酸的定量。该方法特别适用于检测例如发酵培养基中的氨基酸,因为α-羟基酸可以与多种其他有机底物和产物平行进行定量。氨基酸在酸性KNO 2中转化为相应的α-羟基酸解决方案。通过添加NaOH终止反应,并通过等度HPLC分离α-羟基酸,并通过折射率或UV吸收检测进行定量。对18种经典氨基酸进行亚硝化;甘氨酸,大号丙氨酸,大号-缬氨酸,大号l-亮氨酸,大号-异亮氨酸,大号-甲硫氨酸,大号-丝氨酸,大号-苏氨酸,大号天冬酰胺,大号谷氨酰胺,大号天冬氨酸,大号谷氨酸,大号-脯氨酸,L-半胱氨酸,L-苯丙氨酸,L-赖氨酸,L-酪氨酸和L-色氨酸形成可检测的亚硝化产物。然而,L-赖氨酸需要在96 mM甲酸中孵育才能产生可检测的产物,而L-苯丙氨酸必须在120
Component-Selective and Stereocontrolled One-Step Three-Component Reaction among Aldehydes, Amines, and Allenyl Boronic Acids or Allenyl Pinacolboronates
作者:Fotini Liepouri、Giovanni Bernasconi、Nicos A. Petasis
DOI:10.1021/acs.orglett.5b00024
日期:2015.4.3
A one-step, three-component condensation of allenyl boronic acids or allenyl pinacolboronates with amines and aldehydes affords α-allenyl or α-propargyl α-amino acids and anti-β-aminoalcohols. This process gives the allenyl or propargyl product depending on the amine and boron components. Secondary amines generate exclusively α-allenyl α-amino acids, while primary aliphatic amines lead to α-propargyl