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.

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.

A MOF based on a lead(II) 2-oxido-6-methylpyridine-4-carboxylate network

2020 ◽  
Vol 75 (4) ◽  
pp. 365-369
Author(s):  
Long Tang ◽  
Yu Pei Fu ◽  
Na Cui ◽  
Ji Jiang Wang ◽  
Xiang Yang Hou ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Carboxylic Acid ◽  
Thermogravimetric Analysis ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
X Ray ◽  
Connected Node ◽  
Metal Organic ◽  
Solid State Fluorescence

AbstractA new metal-organic framework, [Pb(hmpcaH)2]n (1), has been hydrothermally synthesized from Pb(OAc)2 · 3H2O and 2-hydroxy-6-methylpyridine-4-carboxylic acid (hmpcaH2; 2), and characterized by IR spectroscopy, elemental and thermogravimetric analysis, and single-crystal X-ray diffraction. In complex 1, each hmpcaH− ligand represents a three-connected node to combine with the hexacoordinated Pb(II) ions, generating a 3D binodal (3,6)-connected ant network. The crystal structure of 2 was determined. The solid-state fluorescence properties of 1 and 2 were investigated.

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

ChemInform Abstract: Hydroxyl-Directed Reduction of β-Hydroxycycloalkanones as a Stereoselective Route to 1,3-Diols: X-Ray Crystal Structure and Structural Features of (1R*,2R*,6S*)-2-(Hydroxy(phenyl)methyl) cyclopentanol.

ChemInform ◽  
2010 ◽  
Vol 26 (29) ◽  
pp. no-no
Author(s):  
S. H. J. THOMPSON ◽  
M. F. MAHON ◽  
K. C. MOLLOY ◽  
M. S. HADLEY ◽  
T. GALLAGHER
Keyword(s):  
Crystal Structure ◽  
Structural Features ◽  
X Ray

New Ternary Phosphide La7Pd17P12: Preparation and Crystal Structure

2002 ◽  
Vol 57 (12) ◽  
pp. 1409-1413 ◽  
Author(s):  
S. Budnyk ◽  
Yu. Prots ◽  
Yu. Kuz’ma ◽  
Yu. Grin
Keyword(s):  
Crystal Structure ◽  
Temperature Region ◽  
Large Family ◽  
Structural Features ◽  
Structural Motif ◽  
Crystal Data ◽  
Monoclinic Structure ◽  
X Ray ◽  
Data Space ◽  
Metal Ratio

The title compound was prepared from elements by sintering in the temperature region between 1073 and 1473 K. The monoclinic structure of La7Pd17P12 was solved and refined from X-ray single crystal data: space group C2/m, a = 24.519(1), b = 4.0859(5), c = 13.6106(8)Å , β = 112.129(3)°, Z = 2, RF = 0.025 for 1065 unique of 4877 measured reflections and 112 refined parameters. Main structural motif of the new phosphide are condensed blocks of trigonal prisms around phosphorus atoms connected to infinite chains via lanthanum atoms. The structural features of La7Pd17P12 are discussed in comparison with some representatives of a large family of structures with metal / non-metal ratio close to 2 : 1.

The Transition Metal-rich Orthophosphate Arrojadite with Special Structural Features

2010 ◽  
Vol 65 (12) ◽  
pp. 1427-1433 ◽  
Author(s):  
Christoph Kallfaß ◽  
Constantin Hoch ◽  
Hermann Schier ◽  
Arndt Simon ◽  
Helmut Schuber
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Single Crystal ◽  
Structural Features ◽  
Nickel Plate ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Different Types ◽  
New Feature

The crystal structure of the transition metal-rich orthophosphate mineral arrojadite was reexamined, and the disorder phenomena were analyzed applying modern X-ray single-crystal diffraction and refinement methods on samples from Nickel Plate (USA) and Hagendorf (Germany). As a new feature of the arrojadite structure, two different types of channels oriented along [010] are described. The occupancy of the atomic positions inside these channels have been elucidated.

scholarly journals Thermal, spectroscopic, X-ray and theoretical studies of metal complexes (sodium, manganese, copper, nickel, cobalt and zinc) with pyrimidine-5-carboxylic and pyrimidine-2-carboxylic acids

2019 ◽  
Vol 138 (4) ◽  
pp. 2813-2837 ◽  
Author(s):  
G. Świderski ◽  
R. Świsłocka ◽  
R. Łyszczek ◽  
S. Wojtulewski ◽  
M. Samsonowicz ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Nitrogen Atom ◽  
Metal Complexes ◽  
General Formula ◽  
Pyrimidine Ring ◽  
Carboxylate Ligand ◽  
Metal Centers ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
3D Metal Complexes

Abstract The new 3d metal complexes of pyrimidine-2-carboxylic (2PCA) and pyrimidine-5-carboxylic (5PCA) acids were synthesized and characterized using thermal analysis (TG–DSC, TG–FTIR), X-ray, spectroscopic (IR, Raman) methods and theoretical (DFT) studies. In the complexes of pyrimidine-2-carboxylic acid of the general formula M(2PCA)2·xH2O (where 2PCA-pyrimidine-2-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 0 for Mn and Cu; x = 2 for Co, Ni and Zn) coordination of metal ions occurs through nitrogen atom from pyrimidine ring and carboxylate oxygen atom. The complexes of pyrimidine-5-carboxylic acid of the general formula M(5PCA)2·xH2O (where 5PCA—pyrimidine-5-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 6 for Cu and 4 for remaining complexes) were obtained as monomeric isostructural compounds. Coordination of metal centers occurs through two nitrogen atom from different pyrimidine-5-carboxylate ligand and four oxygen atoms from water molecules. The IR and Raman spectra of free acids as well as obtained metal(II) complexes were described in detail. Aromaticity (HOMA, EN, GEO and I6) of complexes was determined and discussed. The investigated compounds decompose in air in two main stages connected with dehydration and decomposition/burning of anhydrous compounds to the suitable metal oxides. Thermal decomposition in nitrogen leads to the evolution of water, carbon oxides, ammonia and pyrimidine molecules.

A New Supramolecular Synthon Using N-Methylaniline. The Crystal Structure of the 1 : 1 Adduct of N-Methylaniline with 5-Nitrofuran-2-carboxylic Acid

1998 ◽  
Vol 51 (9) ◽  
pp. 867 ◽  
Author(s):  
Daniel E. Lynch ◽  
Lisa C. Thomas ◽  
Graham Smith ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Proton Transfer ◽  
Single Crystal ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Supramolecular Synthon ◽  
X Ray ◽  
C 23 ◽  
A Cell

The crystal structure of the 1 : 1 adduct of N-methylaniline with 5-nitrofuran-2-carboxylic acid has been determined by single-crystal X-ray diffraction. Crystals are monoclinic, space group P21/c with Z 4 in a cell of dimensions a 8·467(5), b 6·106(2), c 23·95(1) Å, β 94·48(3)°. The molecules associate in a tetrameric, proton-transfer formation which has potential as a new supramolecular synthon.

Studies Directed Towards the Total Synthesis of Anticapsin. X-Ray Crystal-Structure of (1RS,2SR,4RS,5RS,6SR)-5-Hydroxy-2-phthalimido-1-trimethylsilyloxy-bicyclo[2.2.2]octane-2,6-carbolactone

1990 ◽  
Vol 43 (11) ◽  
pp. 1827 ◽  
Author(s):  
MJ Crossley ◽  
TW Hambley ◽  
AW Stamford
Keyword(s):  
Crystal Structure ◽  
Amino Acid ◽  
Total Synthesis ◽  
Synthetic Approach ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
X Ray ◽  
X Ray Crystallography ◽  
Relative Stereochemistry ◽  
Atomic Parameters

The relative stereochemistry of methyl 2-phthalimido-1- trimethylsilyloxybicyclo[2.2.2]oct-5-ene-2-carboxylate (9) and its 5,6-epoxide (10), intermediates in a synthetic approach to the amino acid antibiotic anticapsin, were established by the TiCl4-mediated cyclization of (10) to the carbolactone (12); the structure of which was proved by single-crystal X-ray crystallography. Full-matrix least- squares refinement of all atomic parameters with individual isotropic thermal parameters for the hydrogen atoms by using 1446 reflections converged at R 0.036. Crystals of (12) are monoclinic, P21/c, a 12.342(3), b 12.239(2), c 13.405(3) Ǻ, β 99.34(2)°, Z 4.

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