- Preparation method of beta-homoglutamic acid
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The invention belongs to the field of preparation of organic compounds, and provides a preparation method of beta-homoglutamic acid. The method is characterized in that: 3-cyclohexenecarboxylic acid is used as a raw material, beta-homoglutamic acid is synthesized at a high yield through three the steps of reactions of Curtius rearrangement, olefin oxidation and protection group removal, and beta-homoglutamic acid with high yield and high optical purity can be obtained through configuration retention by using optically pure 3-cyclohexenecarboxylic acid. The method has the advantages of easily available raw materials, mild reaction conditions and low cost, and is suitable for large-scale preparation of beta-homoglutamic acid.
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Paragraph 0022; 0033-0034
(2020/11/05)
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- Stereospecific radiosynthesis of 3-fluoro amino acids: Access to enantiomerically pure radioligands for positron emission tomography
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A variety of substituted non-racemic aziridine-2-carboxylates equivalent to amino acids were prepared and subjected to ring opening reaction by [18F/19F]fluoride. The regio and stereospecific ring opening depends on the substituents on the nitrogen as well as both the carbons of aziridines. The applicability of the methods to afford access to 3-[18F/19F]fluoro amino acids are illustrated.
- Alluri, Santosh R.,Riss, Patrick J.
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supporting information
p. 2219 - 2224
(2018/04/05)
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- VITAMIN COMPRISING PYROLOQUINOLINE QUINONE AND USE THEREOF
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It is an object of the present invention to clarify the biochemical role of pyrroloquinoline quinone (PQQ) in living bodies by identifying an enzyme that uses PQQ as a coenzyme in mammals and then by clarifying the oxidation-reduction reaction, with which PQQ is associated as a coenzyme in living bodies. The present invention provides a method of using pyrroloquinoline quinone as a coenzyme for 2-aminoadipate 6-semialdehyde dehydrogenase.
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Page/Page column 20
(2008/06/13)
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- TOTAL SYNTHESIS OF ENANTIOMERICALLY PURE D-α-AMINOADIPIC ACID
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The diastereoselective cyclization of amidal (S,R)-2a, promoted by Hg(OTFA)2, afforded the imidazolidin-4-one (1'S,2R,5R)-3a as a single diastereoisomer. The subsequent transformation of the carbon-mercury bond and the acid hydrolysis of the heterocycle gave enantiomerically pure D-α-aminoadipic acid.
- Amoroso, Rosa,Cardillo, Giuliana,Romero, Marta Susana,Tomasini, Claudia
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- Effect of the Side Chain on the Racemization of Amino Acids in Aqueous Solution
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The rate of racemization of 13 amino acids possessing hydroxy, carboxy, alkoxy, carboalkoxy, alkyl, aryl, and thioether side chains were compared.Reaction conditions were identical for all amino acids studied.Gas chromatography was used to determine the percent of D isomer present.Hydroxy amino acids racemized most rapidly, but conversion to an ether function reduced the rate considerably.The increased racemization rate of methionine (R = CH2CH2SCH3) over Ala (R = CH3) has been attributed to orbital overlap from the sulfur.Asp racemized faster than Glu, α-aminoadipic acid, and pyroglutamic acid. β- and γ-monomethyl esters of aspartic and glutamic acids, respectively, racemized only slightly faster than the corresponding free acids.The slight increase in rate appears attributable to a solvent change brought on by ester hydrolysis.Under the reaction conditions, pH 8 and 140 deg C, hydrolysis of the esters competed favorably with racemization at the methine carbon.The relatively lower racemization rate observed in the case of Glu compared with Asp resulted from the slow formation of pyroglutamic acid.Pyroglutamic acid racemized at a considerably slower rate than acidic amino acids.The differences in the racemization rates with changes in the R group are discussed in terms of several factors, including intramolecular reactions, direct field effects, orbital overlap, and solvation effects, as well as inductive, resonance, and steric factors.
- Smith, Grant Gill,Reddy, G. Vanita
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p. 4529 - 4535
(2007/10/02)
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- CARBOHYDRATES AS CHIRAL TEMPLATES: ASYMMETRIC UGI-SYNTHESIS OF ALPHA-AMINO ACIDS USING GALACTOSYLAMINES AS THE CHIRAL MATRICES
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In the presence of Lewis acid catalysts O-acetyl- (1) and O-pivaloyl- (2) protected β-D-galactopyranosylamines react with aldehydes, isocyanides and carboxylic acids in Ugi-four-component-condensations to give the corresponding N-galactosyl-amino acid amide derivatives 3, 5 in almost quantitative yields.Zinc chloride is the most effective Lewis acid catalyst.At 0 deg C or even at room temperature the (2R,β-D)-diastereomers of the amino acid derivatives 3, 5 are formed with high diastereoselectivity.If the sterically more demanding O-pivaloyl galactosylamine 2 is used at -78 deg C to -25 deg C the stereoselectivity often exeeds 20:1 favouring the (2R,β-D) diastereomers 5.After one recrystallisation pure (R)-amino acid derivatives 5 are obtained in yields of 80-95percent.In addition to the high yields and stereoselectivity the amino acid synthesis described here has the further advantage that it neither requires organometallic reagents and intermediates nor exclusion of oxygen and moisture.Two step acid hydrolysis of the N-galactosylamino acid amide derivatives 5 delivers the enantiomerically pure (R)-amino-acids 8 in high yields.
- Kunz, Horst,Pfrengle, Waldemar
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p. 5487 - 5494
(2007/10/02)
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- SYNTHESIS OF THE RACEMIC AND OPTICALLY ACTIVE FORMS OF GIZZEROSINE, THE INDUCER OF GIZZARD EROSION IN CHICKS
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The racemate end both the (R)- and (S)-forms of gizzerosine were synthesised, and the (S)-isomer was identified as the toxic substance in fish meal causing severe gizzard erosion (black vomit) in chicks.
- Mori, Kenji,Sugai, Takeshi,Maeda, Yukari,Okazaki, Tomomi,Noguchi, Tadashi,Naito, Hiroshi
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p. 5307 - 5312
(2007/10/02)
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- Synthesis of (R)-5-Aminohex-2-enedioic acid and the (+/-)-2-Bromo Derivative as Unsaturated Analogues of the Neurotransmitter Antagonist D-&α-Aminoadipic Acid
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5-Aminohex-2-enedioic acid (2), an unsaturated analogue of the neurotransmitter antagonist D-α-aminoadipic acid, has been synthesised by a convenient route using a phase-transfer alkylation of N-diphenylmethyleneglycine ethyl ester.The unsaturated amino acid has been resolved and the absolute stereochemistry of the (-) isomer determined as R by reduction to D-α-aminoadipic acid.A more conventional synthetic scheme failed to yield (2), but led to the preparation of the (+/-)-2-bromo derivative (4) in low yield.
- Allan, Robin D.
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p. 4658 - 4667
(2007/10/02)
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