1115-47-5Relevant articles and documents
Rhodium-catalysed racemisation of N-acyl α-amino acids
Hateley, Martin J.,Schichl, Daniel A.,Kreuzfeld, Hans-J?rn,Beller, Matthias
, p. 3821 - 3824 (2000)
The first transition metal-catalysed racemisation of N-acyl α-amino acids, which is of importance for kinetic resolution processes, is described. Enantiomerically pure N-acyl α-amino acids were efficiently racemised under mild conditions using various rhodium complexes as catalysts, e.g. [Rh(cod)Cl]2, in the presence of phosphines. (C) 2000 Elsevier Science Ltd.
Kinetic study of stereochemical and other factors governing hydrolytic cleavage of a peptide ligand in binuclear palladium(II) complexes
Chen, Xiaohua,Zhu, Longgen,Yan, Hong,You, Xiaozeng,Kostic, Nenad M.
, p. 2653 - 2658 (1996)
The dipeptide N-acetylmethionylglycine (MeCO-Met-Gly) reacted, via the thioether group in the methionyl side chain, with five different palladium(II) aqua complexes. The complexes cis-[Pd(en)(H2O)2]2+ (en = H2NCH2CH2NH2) and cis-[Pd(pn)(H2O)2]2+ (pn = H2NCH2CH2CH2NH2) yield [Pd2(μ-MeCO-Met-Gly)2(H2O)4] 4+ A, cis-[Pd(Met-S,N)(H2O)2]2+ yields trans-[Pd2(μ-MeCO-Met-Gly)2(H2O) 2(HMet)2]6+, B and trans-[Pd2{Cys(Me)-S,N}2(H2O)2] 4+ [Cys(Me) = S-methylcysteine] yields trans-[Pd2{μ-HCys(Me)}2(H2O) 2(MeCO-Met-Gly)2]6+ C. The complex cis-[Pd(dtco)(H2O)2]2+ (dtco = 1,5-dithiacyclooctane) yields [Pd2(μ-MeCO-Met-Gly)2(dtco)2]4+, D. These reactions and hydrolytic cleavage of the methionine-glycine amide bond in the co-ordinated MeCO-Met-Gly are conveniently monitored by 1H NMR spectroscopy. The rate of cleavage decreases in the order A > B ≈ C > D, in which the number of aqua ligands per peptide ligand decreases. Intramolecular attack by aqua ligands is more efficient than external attack by water molecules from the solvent. The peptide ligands occupying terminal and bridging positions in the binuclear palladium(II) complexes undergo hydrolysis at similar rates. This study shows the importance of polynuclear metal complexes in hydrolytic cleavage of peptide bonds.
Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
Kyne, Sara Helen,Li, Jiacheng,Siang Tan, Suan,Wai Hong Chan, Philip
supporting information, (2022/01/11)
A synthetic method that enables the Hantzsch ester-mediated Minisci-type C2-alkylation of quinolines, isoquinolines and pyridines by N-(acyloxy)phthalimide esters (NHPI) under blue LED (light emitting diode) light (456 nm) is described. Achieved under mild reaction conditions at room temperature, the metal-free synthetic protocol was shown to be applicable to primary, secondary and tertiary NHPIs to give the alkylated N-heterocyclic products in yields of 21–99%. On introducing a chiral phosphoric acid, an asymmetric version of the reaction was also realised and provided product enantiomeric excess (ee) values of 53–99%. The reaction mechanism was delineated to involve excitation of an electron-donor acceptor (EDA) complex, formed from weak electrostatic interactions between the Hantzsch ester and NHPI, which generates the posited radical species of the redox active ester that undergoes addition to the N-heterocycle.
Methionine derivative and application thereof
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Paragraph 0041-0049, (2020/12/06)
The invention relates to the technical field of chemical synthesis, and particularly discloses a methionine derivative and application thereof. The structure of the methionine derivative is shown as aformula (I). The methionine derivative provided by the invention is used as an oxidizing agent to be applied to an oxidation system, hydroxyl of a reaction substrate is oxidized into corresponding aldehyde or ketone, and no peculiar smell substance is generated in the reaction process; the yield of a target product is guaranteed, meanwhile, the reaction temperature can be effectively increased, the oxidation reaction can be normally conducted at the temperature higher than 0 DEG C, and the yield is high; and the methionine derivative can be recycled many times, the cost is saved, energy is saved, consumption is reduced, and the methionine derivative is environmentally friendly.
Reactivity of α-Amino Acids in the Reaction with Esters in Aqueous–1,4-Dioxane Media
Kochetova,Kustova,Kuritsyn
, p. 80 - 85 (2018/03/09)
The kinetics of the reaction of a series of α-amino acids with 4-nitrophenyl acetate, 4-nitrophenyl benzoate, and 2,4,6-trinitrophenyl benzoate in aqueous 1,4-dioxane medium has been studied. Kinetics of the reactions involving 4-nitrophenyl acetate and 2,4,6-trinitrophenyl benzoate has complied with the Br?nsted dependence and revealed linear correlation between rate constant logarithm and the energy difference of the frontier orbitals of α-amino acids anions.
Synthesis method for organic synthesis of intermediate N-acetyl-DL-methionine
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Paragraph 0006; 0014; 0015, (2018/07/30)
The invention relates to a synthesis method for organic synthesis of an intermediate N-acetyl-DL-methionine. The method mainly includes the steps of: adding 3mol DL-methionine into 4-5mol 4-bromo-acetanilide for heating dissolution, adding 4-5mol bromoethylamine, conducting reflux for 90-120min, adding a 300ml ethanol solution, carrying out concentration and evaporation to dryness, lowering the temperature of the residue to 10-15DEG C, performing washing with a toluene solution, conducting washing with a nitroethane solution, conducting recrystallization in a butanol solution, and performing dehydration with a dehydrant, thus obtaining the finished product N-acetyl-DL-methionine.
Separation and purification method for N-acetyl-D, L-methionine
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Paragraph 0037-0041, (2017/06/08)
The invention discloses a separation and purification method for N-acetyl-D, L-methionine. The method comprises the steps of 1) subjecting an acetylation reagent and methionine salt to the acetylation reaction, adjusting the pH value of the reaction solution to be 3-5 by using an acidifying agent, maintaining the temperature of the reaction solution to be 50 DEG C-75 DEG C, and subjecting the reaction solution to the decoloration treatment; 2) adopting water as an eluent, subjecting the decolored reaction solution to the continuous chromatographic separation treatment through a continuous chromatographic separation system to respectively obtain an N-acetyl-D, L-methionine aqueous solution and a saline solution containing sodium acetate. The method enables the high-purity separation of N-acetyl-D, L-methionine, wherein the N-acetyl-D, L-methionine is completely and effectively separated from organic salts and inorganic salts. Therefore, the usage of organic solvents, toxic and harmful to the traditional production process, is avoided. Meanwhile, the method is low in energy consumption, high in production efficiency and simple in operation. The method improves the product yield and the product purity, which is green and environmentally-friendly.
A process for the preparation of L-methionine
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Paragraph 0052-0054, (2017/03/24)
The invention aims to the field of chemical engineering, and relates to a method for preparing L-methionine. According to the method, acetylated saponification liquid is used as production raw material, acid is added into the raw material, the pH is adjusted to be acidic, after reduced pressure distillation, an organic solvent is used for treatment, so that a solution containing D,L-acetyl methionine is obtained, then the organic solvent is removed to obtain D,L-acetyl methionine crystals, and a resolution reaction is performed on the produced D,L-acetyl methionine crystals, so that the L-methionine is obtained; the technology does not need refined D,L-methionine, the soponification liquid for producing the D,L-methionine is used for performing an acetylated reaction, and therefore production cost is reduced; after the acetylation, water is evaporated to dryness, the organic solvent is used for desalting, the yield of the D,L-acetyl methionine reaches 97-99%, and the purity of the D,L-acetyl methionine reaches above 96%; the enzymolysis speed of the D,L-acetyl methionine is higher than that of a traditional method, the obtained L-methionine is good in crystal form and whiteness, the purity reaches above 99.5%, and the total yield of the L-methionine is improved to 78%; according to the technology, a circulation technology is integrated, the design is reasonable, and production cost is reduced.
Flavour Modifying Compounds
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Page/Page column, (2014/05/20)
A compound of formula (I) is used to modify the taste or flavour of a flavour composition or consumable product, wherein R1 is H, or a substituted, unsubstituted, branched or unbranched C1-C5 alkyl group and, NHR2 is a residue of an amino acid, is selected from Alanine (Ala), cysteine (Cys), Aspartic acid (Asp), phenylalanine (Phe), glutamic acid (Glu), histidine (His), isoleucine (Ile), lysine (Lys), leucine (Leu), methionine (Met), asparagines (Asn), glutamine (Gln), arginine (Arg), serine (Ser), theronine (Thr), valine (Val), tryptophan (Trp), tyrosine(Tyr) and Glycine (Gly), with the proviso that the compound is not N-acetyl glycine. Also disclosed are flavour compositions and consumable products containing such compounds.
Studies on the biodegradation of fosfomycin: Synthesis of 13C-labeled intermediates, feeding experiments with rhizobium huakuii PMY1, and Isolation of Labeled Amino Acids from Cell Mass by HPLC
McGrath, John W.,Hammerschmidt, Friedrich,Kaehlig, Hanspeter,Wuggenig, Frank,Lamprecht, Guenther,Quinn, John P.
experimental part, p. 13341 - 13348 (2012/03/22)
Racemic (1R*,2R*)-1,2-dihydroxy-[1-13C 1]propylphosphonic acid and 1-hydroxy-[1-13C 1]acetone were synthesized and fed to R. huakuii PMY1. Alanine and a mixture of valine and methionine were isolated as their N-acetyl derivatives from the cell hydrolysate by reversed-phase HPLC and analyzed by NMR spectroscopy. It was found that the carbon atoms of the respective carboxyl groups were highly 13C-labeled (up to 65 %). Hydroxyacetone is therefore considered an obligatory intermediate of the biodegradation of fosfomycin by R. huakuii PMY1.
