14328-51-9Relevant articles and documents
Ruthenium-catalyzed hydrogenation of aromatic amino acids in aqueous solution
Sun, Bing,Süss-Fink, Georg
, p. 81 - 86 (2016)
A catalyst containing metallic ruthenium nanoparticles intercalated in hectorite (nanoRu@hectorite) was found to catalyze the hydrogenation of aromatic amino acids in aqueous solution. Thus, l-phenylalanine and l-phenylglycine can be converted exclusively into the corresponding l-cyclohexyl amino acids with retention of chirality under mild conditions (60 °C, 40 bar), conversion and selectivity being superior to 99%. The catalyst can be recycled and reused at least three times without loss in activity and selectivity.
Synthesis of enantiomerically pure cyclohexylglycine
Minnaard, Adriaan J.,Boesten, Wilhelmus H. J.,Zeegers, Hubertus J. M.
, p. 4327 - 4332 (1999)
(S)-cyclohexylglycine (1) is prepared in high yield by hydrogenation of (S)-phenylglycine (2) using rhodium on carbon as the catalyst.
SYNTHESIS METHOD FOR L-CYCLIC ALKYL AMINO ACID AND PHARMACEUTICAL COMPOSITION HAVING THEREOF
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Paragraph 0073; 0097, (2016/11/17)
A synthesis method for L-cyclic alkyl amino acid and a pharmaceutical composition having the said amino acid are provide in the present disclosure provides. The synthesis method comprises: step A.) preparing a cyclic alkyl keto acid or a cyclic alkyl keto acid salt having Structural Formula (I) or Structural Formula (II), and step B.) mixing the cyclic alkyl keto acid or the cyclic alkyl keto acid salt with ammonium formate, a leucine dehydrogenase, a formate dehydrogenase and a coenzyme NAD+, and carrying out a reductive amination reaction to generate the L-cyclic alkyl amino acid, wherein the Structural Formula (I) is where n1≧1, m1≧0 and the M1 is H or a monovalent cation; the Structural Formula (II) is where n2≧0, m2≧0, the M2 is H or a monovalent cation, an amino acid sequence of the leucine dehydrogenase is SEQ ID No.1.
Reductions of aromatic amino acids and derivatives
Ager, David J.,Prakash, Indra
, p. 164 - 167 (2013/09/05)
Catalytic reduction of phenylalanine and phenylglycine derivatives can be achieved with rhodium on carbon or alumina to give good yields of the corresponding cyclohexyl derivatives. The procedure can be scaled.
Practical and convenient enzymatic synthesis of enantiopure α-amino acids and amides
Wang, Mei-Xiang,Lin, Shuang-Jun
, p. 6542 - 6545 (2007/10/03)
Catalyzed by the nitrile hydratase and the amidease in Rhodococcus sp. AJ270 cells under very mild conditions, a number of α-aryl- and α-alkyl-substituted DL-glycine nitriles 1 rapidly underwent a highly enantioselective hydrolysis to afford D-(-)-α-amino acid amides 2 and L-(+)-α-amino acids 3 in high yields with excellent enantiomeric excesses in most cases. The overall enantioselectivity of the biotransformations of nitriles originated from the combined effects of a high L-enantioselective amidase and a low enantioselective nitrile hydratase. The influence of the substrates on both reaction efficiency and enantioselectivity was also discussed in terms of steric and electronic effects. Coupled with chemical hydrolysis of D-(-)-α-phenylglycine amide, biotransformation of DL-phenylglycine nitrile was applied in practical scale to produce both D- and L-phenylglycines in high optical purity.
Efficient chemoenzymatic synthesis of enantiomerically pure α-amino acids
Beller, Matthias,Eckert, Markus,Geissler, Holger,Napierski, Bernd,Rebenstock, Heinz-Peter,Holla, E. Wolfgang
, p. 935 - 941 (2007/10/03)
A general two-step chemoenzymatic synthesis for enantiomerically pure natural and nonnatural α-amino acids is presented. In the first step of the sequence, the ubiquitous educts aldehyde, amide and carbon monoxide react by palladium-catalyzed amidocarbonylation to afford the racemic N-acyl amino acids in excellent yields. In the second step, enzymatic enantioselective hydrolysis yields the free optically pure a-amino acid and the other enantiomer as the N-acyl derivative, both in optical purities of 85-99.5% ee. The advantage of the chemoenzymatic process compared to other amino acid synthesis are demonstrated by the preparation of various functionalized (-OR, -Cl, -F, -SR) α-amino acids on a 10-g scale.
ENDOTHELIN CONVERTING ENZYME INHIBITORS
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, (2008/06/13)
Compounds are disclosed which inhibit endothelin converting enzyme. These compounds are useful for treating hypertension, congestive heart failure, myocardial infarction, reperfusion injury, coronary angina, cerebral vasospasm, acute renal failure, non-steroidal antiinflammatory drug induced gastric ulceration, cyclosporin induced nephrotoxicity, endotoxin-induced toxicity, asthma and atherosclerosis.
CCK-B agonist or antagonist activities of structurally hindered and peptidase-resistant Boc-CCK4 derivatives
Corringer,Weng,Ducos,Durieux,Boudeau,Bohme,Roques
, p. 166 - 172 (2007/10/02)
Replacement of Met31 by (N-Me)Nle in CCK8 or CCK4 has been shown to improve the affinity and selectivity for CCK-B receptors. In order to obtain molecules with enhanced bioavailability, two novel series of protected tetrapeptides of the general formula Boc-Trp30-X-Asp-Y33 have been developed. Introduction of (N-Me)Nle and the bulky, aromatic naphthylalaninamide (Nal-NH2) in positions X and Y, respectively, does not greatly modify the affinity for guinea pig brain CCK-B receptors. In contrast, incorporation of hindering N-methyl amino acids such as (N-Me)Phe, (N-Me)Phg, or (N-Me)Chg, but not their non-methylated counterparts, in position X induced a large decrease in affinity for the CCK-B binding sites. Among the various peptides synthesized, Boc-[(N-Me)Nle31,1Nal- NH233]CCK4 (2) (K(I) = 2.8 nM), Boc-[Phg31,1Nal-NH233]CCK4 (15) (K(I) = 14 nM), and Boc-[Phg31,1Nal-N(CH3)233]CCK4 (17) (K(I) = 39 nM) displayed good affinities for brain CCK-B receptors and had good selectivity ratios. These pseudopeptides, in which the presence of unnatural and hydrophobic residues is expected to improve their penetration of the central nervous system, were shown to be very resistant to brain peptidases. Interestingly, whereas compounds 2 and 15 proved to be full agonists for rat hippocampal CCK-B receptors when measured in an electrophysiological assay, compound 17 behaved as a potent antagonist in the same test and displayed a good affinity in rat brain K(I)(CCK-B) = 51 nM as compared to the Merck antagonist L365,260, K(I)(CCK-B) = 12 nM. This illustrates a simple means to obtain CCK-B antagonists and suggests that the free, CONH2 group plays a critical role in the recognition of the agonist state of brain CCK-B receptors.
STRUCTURAL STUDIES OF GLYCOPEPTIDE ANTIBIOTIC A35512B. IDENTIFICATION OF THE DIPHENYL ETHER-TYPE BIS(AMINO ACID).
Harris, Constance M.,Harris, Thomas M.
, p. 1661 - 1666 (2007/10/02)
A35512B is one of the components of the A35512 complex of glycopeptide antibiotics recently isolated from Streptomyces candidus.Hydrolysis of the aglycone with 6N HCl gave actinoidinic acid (6), and the previously reported Cl-containing diphenyl ether-type bis(phenylglycine) 2.Hydrolysis of the aglycone in 57percent HI gave 6, tris(amino acid) 5b arising from reduction of the β-OH groups of amino acid 5a, and amino acid 7, formed by dehalogenation of 2.Amino acids 2 and 7 were oxidatively degraded to bis(benzoates) 3d and 10.The structures of 3d and 10 were confirmed by independent syntheses.Amino acid 2 is assigned structure 2d rather than the previously proposed structures 2a or 2b.The absolute configuration of 2d was determined as R for the para-hydroxylated ring and S for the meta-hydroxylated ring.
