- Thermochemistry of the hydrolysis of L-arginine to (L-citrulline + ammonia) and of the hydrolysis of L-arginine to (L-ornithine + urea)
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Molar enthalpies of reaction for the hydrolysis of L-arginine(aq) to and for the hydrolysis of L-arginine(aq) to have been measured by microcalorimetry.These reactions are catalyzed, respectively, by arginase and by arginine deiminase.The effects of variations in pH, temperature, and ionic strength on the molar enthalpies of reaction were studied.The results have been analyzed with a model which accounts for the complex equilibria in solution.The results obtained at T = 298.15 K for the reference reactions are: ΔfHm0 = -(21.4+/-0.5) kJ * mol-1 for L-arginine+(aq) + H2O(l) = L-ornithine+(aq) + urea(aq) and ΔfHm0 = -(31.9+/-0.8) kJ * mol-1 for L-arginine+(aq) + H2O(l) = L-citrulline(aq) + NH4+(aq).These results are discussed in terms of thermodynamic-cycle calculations and in terms of the metabolic urea cycle.
- Tewari, Y. B.,Kishore, N.,Margolis, S. A.,Goldberg, R. N.,Shibatani, T.
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- Highly enantioselective synthesis of non-natural aliphatic α-amino acids via asymmetric hydrogenation
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By employing a rhodium-Duanphos complex as the catalyst, β-alkyl (Z)-N-acetyldehydroamino esters were smoothly hydrogenated in a highly efficient and enantioselective way. Excellent enantioselectivities together with excellent yields were achieved for a series of substrates. An efficient approach for the synthesis of the intermediate of the orally administered anti-diabetic drugs Alogliptin and Linagliptin in the DPP-4 inhibitor class was also developed.
- Ji, Jianjian,Chen, Caiyou,Cai, Jiayu,Wang, Xinrui,Zhang, Kai,Shi, Liyang,Lv, Hui,Zhang, Xumu
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supporting information
p. 7624 - 7627
(2015/07/15)
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- Synthesis of (ε-13C-,ε-15N)-enriched L-lysine - Establishing schemes for the preparation of all possible 13C and 15N isotopomers of L-lysine, L-ornithine, and L-proline
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In this paper we describe a simple synthetic strategy that, with the right rational adaptation, gives direct access to any 13C/15N isotopomer of L-glutamate, L-ornithine, L-proline, L-lysine, and L-α, amino adipic acid. This strategy also allows access to nonproteinogenic amino acids like L-citrulline in high yields and optical purity. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Siebum, Arjan H. G.,Tsang, Robert K. F.,Van Der Steen, Rob,Raap, Jan,Lugtenburg, Johan
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p. 4391 - 4396
(2007/10/03)
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- Polyunsaturated fatty acid derivatives, pharmaceutical compositions containing the same, method for the preparation thereof, and their use as medicament
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The compounds of the Formula (I) STR1 wherein R1 is a C18-24 alkenyl containing at least two double bonds, or --(CH2)n --CH(NH2)m --COOH X is 0, NH or C1-4 alkyl-N, Y is CONH2, COOH or COOMe, wherein Me is hydrogen metal, and R2 is a side chain of a any amino acid except L-GLU or L-ASP at α-position or a group of Formula wherein k is zero or an integer of 1, n is zero or an integer of 1 to 3, m is zero or an integer of 1 to 4, A is hydroxyl or one A is hydroxyl and the other A is hydrogen. M is H or R1 --CO and X and R1 are as defined above and their salts having tyrosine kinase inhibitor activity can be used as antitumor agents.
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- Aminosaeuren, I. Darstellung von Aminosaeuren aus Halogencarbonsaeure-alkylestern mit Alkalimetallcyanaten
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α- and ω-halo- as well as α,ω-dihalocarboxylic alkyl esters react with potassium cyanate in the presence of alcohol at 80 - 120 deg C in dipolar aprotic solvents to yield α- and ω-(alkoxycarbonylamino)- and α,ω-bis(alkoxycarbonylamino)carboxylic alkyl esters, respectively, in good yields.Hydrolytic cleavage of these mono- or diurethanes with an aqueous solution of hydrochloric acid/formic acid leads to the corresponding amino acid hydrochlorides in nearly quantitative yields.
- Effenberger, Franz,Drauz, Karlheinz,Foerster, Siegfried,Mueller, Wolfgang
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p. 173 - 189
(2007/10/02)
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