126576-99-6Relevant articles and documents
Characterization of N,N-dimethyl amino acids by electrospray ionization-tandem mass spectrometry
Naresh Chary,Sudarshana Reddy,Kumar, Ch. Dinesh,Srinivas,Prabhakar
, p. 771 - 781 (2015/08/18)
Methylation is an essential metabolic process for a number of critical reactions in the body. Methyl groups are involved in the healthy function of the body life processes, by conducting methylation process involving specific enzymes. In these processes, various amino acids are methylated, and the occurrence of methylated amino acids in nature is diverse. Nowadays, mass-spectrometric-based identification of small molecules as biomarkers for diseases is a growing research. Although all dimethyl amino acids are metabolically important molecules, mass spectral data are available only for a few of them in the literature. In this study, we report synthesis and characterization of all dimethyl amino acids, by electrospray ionization-tandem mass spectrometry (MS/MS) experiments on protonated molecules. The MS/MS spectra of all the studied dimethyl amino acids showed preliminary loss of H2O+CO to form corresponding immonium ions. The other product ions in the spectra are highly characteristic of the methyl groups on the nitrogen and side chain of the amino acids. The amino acids, which are isomeric and isobaric with the studied dimethyl amino acids, gave distinctive MS/MS spectra. The study also included MS/MS analysis of immonium ions of dimethyl amino acids that provide information on side chain structure, and it is further tested to determine the N-terminal amino acid of the peptides.
Stable-isotope dimethylation labeling combined with LC-ESI MS for quantification of amine-containing metabolites in biological samples
Guo, Kevin,Ji, Chengjie,Li, Liang
, p. 8631 - 8638 (2008/03/15)
One of the challenges associated with metabolome profiling in complex biological samples is to generate quantitative information on the metabolites of interest. In this work, a targeted metabolome analysis strategy is presented for the quantification of amine-containing metabolites. A dimethylation reaction is used to introduce a stable isotopic tag onto amine-containing metabolites followed by LC-ESI MS analysis. This labeling reaction employs a common reagent, formaldehyde, to label globally the amine groups through reductive animation. The performance of this strategy was investigated in the analysis of 20 amino acids and 15 amines by LC-ESI MS. It is shown that the labeling chemistry is simple, fast (13C-dimethylation does not show any isotope effect on either RPLC or HILIC LC, indicating that 13C-labeling is a preferred approach for relative quantification of amine-containing metabolites in different samples. The isotopically labeled 35 amine-containing analogues were found to be stable and proved to be effective in overcoming matrix effects in both relative and absolute quantification of these analytes present in a complicated sample, human urine. Finally, the characteristic mass difference provides additional structural information that reveals the existence of primary or secondary amine functional groups in amine-containing metabolites. As an example, for a human urine sample, a total of 438 pairs of different amine-containing metabolites were detected, at signal-to-noise ratios of greater than 10, by using the labeling strategy in conjunction with RP LC-ESI Fourier-transform ion cyclotron resonance MS.
Etude par la Modelisation Moleculaire de la Regioselectivite de l'Ouverture des Acides Glycidiques par les Amines Aliphatiques
Grosjean, F.,Huche, M.,Larcheveque, M.,Legendre, J. J.,Petit, Y.
, p. 9325 - 9334 (2007/10/02)
A model for glycidic acids opening reaction by ammonia and amines has been suggested from semi-empiric orbital calculations.It provides a way for evaluating the different interactions between the incoming nucleophile and the oxirane substituents.Steric and coulombic interactions of the carboxylate in staggered conformation (cis substitution) has a major influence to rationalize experimental regioselectivity.
AN EFFICIENT ONE-STEP REDUCTIVE N-MONOALKYLATION OF α-AMINO ACIDS
Ohfune, Yasufumi,Kurokawa, Natsuko,Higuchi, Naoki,Saito, Masayuki,Hashimoto, Masaki,et al.
, p. 441 - 444 (2007/10/02)
Reactions of protection-free α-amino acids with aldehydes or ketones in the presence of sodium cyanoborohydride afforded the N-monoalkylated amino acids in inorganic salt-free form.Application of this method to synthesis of N-alkyl derivatives of biologic
Anodic Oxidation of Amines. IX. Anodic Oxidation Process of α-Amino Acids in Aqueous Buffer of pH 10
Masui, Masaichiro,Kamada, Yoshiyuki,Iizuka, Taeko,Ozaki, Shigeko
, p. 4740 - 4745 (2007/10/02)
Anodic oxidation of α-amino acids with and without a β-hydroxy group was investigated by cyclic voltammetry and controlled potential electrolysis in aqueous carbonate buffer of pH 10.The first wave of the α-amino acids is developed at nearly the same potentials as those observed for the corresponding simple aliphatic amines, showing that a β-hydroxy group does not significantly decrease the first oxidation potential, in contrast to the case of β-alkanolamines.Decarboxylation accompanied by dealkylation is the main reaction process, and a small amount of C-C bond fission also occurs only in the case of the β-hydroxy amino acids.Keywords - α-amino acid; anodic oxidation; decarboxylation; carbon-nitrogen bond fission; carbon-carbon bond fission; aldehyde; N-methyl-α-amino acid; N,N-dimethyl-α-amino acid.
