Isolation from atelia herbert-smithii pittier (sophoreae, leguminosae) and x-ray structure of cis-1-amino-3-hydroxymethyl-cyclobutane-1-carboxylic acid, an achiral non-protein amino acid

Tetrahedron ◽  
1987 ◽  
Vol 43 (8) ◽  
pp. 1857-1861 ◽  
Author(s):  
Geoffrey N. Austin ◽  
Peter D. Baird ◽  
Hak-Fun Chow ◽  
L.E. Fellows ◽  
G.W.J. Fleet ◽  
...  
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Protein Amino Acid ◽  
X Ray

Transformation of the Carboxyl Group of an Amino Acid to Variously Substituted Imidazoles through a Davidson-Type Heterocyclization

Synthesis ◽  
2019 ◽  
Vol 51 (09) ◽  
pp. 1961-1968 ◽  
Author(s):  
Jim Küppers ◽  
Michaela Hympánová ◽  
Tim Keuler ◽  
Andreas Schneider ◽  
Gregor Schnakenburg ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Building Blocks ◽  
Carboxyl Group ◽  
Amino Group ◽  
Combinatorial Approach ◽  
X Ray ◽  
Imidazole Derivatives

The modification of amino acids leads to valuable building blocks for the synthesis of bioactive compounds. By keeping the amino group protected, the carboxylic acid functionality can be converted in two steps into an imidazole moiety via a Davidson-like heterocyclization. This reaction allows for a combinatorial approach, in which two positions at the heterocycle can be modified. Herein, we report the synthesis of such imidazole derivatives by employing N-protected cyclohexylalanine as the starting material. Different α-halo ketones were used and two points of diversity, positions 4 and 5, were examined. The structure of the final imidazole derivatives was confirmed by three X-ray crystal structure analyses and their protease inhibiting activities were evaluated.

(4R)-Thiazolidine-4-carboxylic acid: ligand specificity and the synthesis and X-ray structure of a cobalt(III) complex

1980 ◽  
Vol 33 (6) ◽  
pp. 1213 ◽  
Author(s):  
GJ Gainsford ◽  
WG Jackson ◽  
AM Sargeson ◽  
AD Watson
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Carboxylate Ligand ◽  
Ligand Specificity ◽  
X Ray ◽  
Acid Ligand ◽  
Carboxylic Acid Ligand

The N,O mode of bonding of the thiazolidine-4-carboxylate ligand and the structure of the Δ-bis-(ethane-1,2-diamine)[(3R,4R)-thiazolidine-4- carboxylato-N,O]cobalt(2+) ion have been determined. The stereospecificity induced by the chiral amino acid between the A and A forms is discussed in relation to analogous proline chemistry.

An Expansion of the Role of the Corey - Link Reaction for the Synthesis of α-Substituted Carboxylic Acid Esters

2006 ◽  
Vol 59 (7) ◽  
pp. 426 ◽  
Author(s):  
Adrian Scaffidi ◽  
Brian W. Skelton ◽  
Robert V. Stick ◽  
Allan H. White
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Methyl Ester ◽  
Single Crystal ◽  
X Ray ◽  
Structure Determinations ◽  
Acid Esters

The treatment of 1,2:5,6-di-O-isopropylidene-α-d-ribo-hexos-3-ulose with chloroform under basic conditions has yielded the normal 3-C-trichloromethyl-α-d-allofuranose derivative. Under the conditions of the modified Corey–Link reaction but with a nucleophile different from the usual azide, a range of α-substituted carboxylic acid esters (and one amide) has been obtained. A similar addition of bromoform to the ulose has formed the α-bromo methyl ester. Two attempts at forming an ‘inositol α-amino acid’ from a polyhydroxylated cyclohexanone failed. Single-crystal X-ray structure determinations are reported for (3S)-1,2:5,6-di-O-isopropylidene-3-C-methoxycarbonyl-3-S-phenyl-3-thio-α-d-ribo-hexose, (3S)-1,2:5,6-di-O-isopropylidene-3-S-phenyl-3-C-(phenylthio)carbonyl-3-thio-α-d-ribo-hexose, 3-deoxy-1,2:5,6-di-O-isopropylidene-3-C-methoxycarbonyl-α-d-erythro-hex-3-enofuranose, 4,6-di-O-benzyl-2-C-trichloromethyl-scyllo-inositol 1,3,5-orthoformate, 2,2'-anhydro-4,6-di-O-benzyl-2-C-dichlorohydroxymethyl-scyllo-inositol 1,3,5-orthoformate, 1,3,4,5,6-penta-O-benzyl-2-C-trichloromethyl-myo-inositol, and 2-amino-1,3,4,5,6-penta-O-benzyl-2-C-cyano-2-deoxy-myo-inositol.

scholarly journals The bovine plasma retinol-binding protein. Amino acid sequence, interaction with transthyretin, crystallization and preliminary X-ray data

1990 ◽  
Vol 192 (2) ◽  
pp. 507-513 ◽  
Author(s):  
Rodolfo BERNI ◽  
Monica STOPPINI ◽  
Maria Carla ZAPPONI ◽  
Maria Laura MELONI ◽  
Hugo L. MONACO ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Protein Amino Acid ◽  
X Ray ◽  
Protein Amino Acid Sequence ◽  
Bovine Plasma ◽  
Plasma Retinol

Die Kristallstruktur des Ectoin, einer neuen osmoregulatorisch wirksamen Aminosäure / The Crystal Structure of Ectoine, a Novel Amino Acid of Potential Osmoregulatory Function

1985 ◽  
Vol 40 (11-12) ◽  
pp. 780-784 ◽  
Author(s):  
Willi Schuh ◽  
Heinrich Puff ◽  
Erwin A. Galinski ◽  
Hans G. Trüper
Keyword(s):  
Crystal Structure ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Halophilic Bacteria ◽  
Pyrimidine Ring ◽  
Structural Features ◽  
Compatible Solute ◽  
X Ray ◽  
Ectothiorhodospira Halochloris ◽  
Osmoregulatory Function

Abstract The crystal structure of ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid) isolated from the extremely halophilic phototrophic bacterium Ectothiorhodospira halochloris was determined by X-ray analysis. This novel cyclic amino acid forms zwitterionic molecules with delocalized π-bonding in the N-C-N group of the hydrated pyrimidine ring. The molecules are connected by N-H ...O hydrogen bonds. The excellent solubility of ectoine in water can be explained by its structural features which also account for its function as a compatible solute in halophilic bacteria.

scholarly journals Some Stereochemical Aspects of the Strecker Synthesis and the Bucherer - Bergs Reaction

2004 ◽  
Vol 57 (5) ◽  
pp. 461 ◽  
Author(s):  
Urs D. Wermuth ◽  
Ian D. Jenkins ◽  
Raymond C. Bott ◽  
Karl A. Byriel ◽  
Graham Smith
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Crystallographic Analysis ◽  
Amino Group ◽  
Keto Ester ◽  
X Ray ◽  
Strecker Reaction ◽  
Strecker Synthesis

Both the Strecker and Bucherer–Bergs reactions convert the norbornane keto ester methyl bicyclo[2.2.1]hept-6-one-2-endo-carboxylate into the lactam 6-endo-aminobicyclo[2.2.1]heptane-2-endo-carboxylic acid-γ-lactam-6-exo-carboxylic acid. This lactam is unusually stable and cannot be hydrolyzed to the corresponding amino acid. The stereochemistry in the Strecker reaction, in which the amino group is endo, is contrary to that expected from literature precedent. The stereochemistry in the Bucherer–Bergs reaction, in which the amino group is also endo, has been confirmed by X-ray crystallographic analysis of the intermediate spirohydantoin (±)-bicyclo[2.2.1]heptane-2-endo-carboxylic acid-6-spiro-5′-hydantoin.

The Synthesis and Structure of a Cyclobutane Analog of Glutamic Acid With an Acetic Acid Side Chain

1995 ◽  
Vol 48 (5) ◽  
pp. 919
Author(s):  
RD Allan ◽  
C Apostopoulos ◽  
TW Hambley
Keyword(s):  
Acetic Acid ◽  
Amino Acid ◽  
Nmda Receptor ◽  
Carboxylic Acid ◽  
Receptor Agonist ◽  
Side Chain ◽  
Synthetic Route ◽  
Trans Orientation ◽  
X Ray ◽  
Cyclobutane Ring

A synthetic route involving a hydantoin derivative of bicyclo [3.2.0]hept-2-ene has been investigated for the preparation of neurotransmitter analogues containing an additional acetic acid substituent on the cyclobutane ring of the potent NMDA receptor agonist trans-1-aminocyclobutane-1,3-dicarboxylic acid. X-Ray analysis showed that the major cyclobutane amino acid produced had the 2-acetic acid and 3-carboxylic acid substituents in the trans orientation as a result of epimerization during hydantoin hydrolysis.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Axially Chiral Bis(α-amino Acid)s and Their Deamino Analogues. Synthesis and Configurational Assignment

1998 ◽  
Vol 63 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Miloš Tichý ◽  
Luděk Ridvan ◽  
Miloš Buděšínský ◽  
Jiří Závada ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nmr Spectra ◽  
Building Blocks ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
X Ray ◽  
Configurational Assignment ◽  
Symmetry Properties ◽  
Axially Chiral ◽  
Polymeric Structures

The axially chiral bis(α-amino acid)s cis-2 and trans-2 as possible building blocks for polymeric structures of novel type of helicity were prepared. Their configuration has been determined by NMR spectroscopy and, in the case of the trans-isomer, confirmed by single-crystal X-ray diffraction. Analogous pair of stereoisomeric diacids cis-3 and trans-3, devoid of the amino groups, was also prepared and their configuration assigned. The observed differences in the NMR spectra of cis- and trans-isomers of 2 and 3 are discussed from the viewpoint of their different symmetry properties.

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