Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine II [1]. X-ray Structure Analysis of Trimethyl(4-oxopentyl)ammonium-chloride

1982 ◽  
Vol 37 (3-4) ◽  
pp. 282-288 ◽  
Author(s):  
Gieren Gieren ◽  
Michail Kokkinidis
Keyword(s):  
Crystal Structure ◽  
Ammonium Chloride ◽  
Structure Analysis ◽  
Quaternary Ammonium ◽  
Fourier Synthesis ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Ammonium Group ◽  
Significant Difference ◽  
Quaternary Ammonium Group

Abstract The crystal structure of Trimethyl(4-oxopentyl)ammonium-chloride ([(CH3)3N+-(CH2)3COCH3]Cl-) (1) was determined by an X-ray structure analysis. 1 crystallizes in the orthorhombic space group P212121 with a = 10.440 (3), b = 14.600 (9), c = 6.804 (9) Å and with four formula units per unit cell. The structure was solved by a Patterson and a successive Fourier synthesis. The least squares refinement yielded an R-value of 0.064 for 1077 observed reflections. The cation of 1 is derived from acetylcholine by replacement of the ester oxygen with a CH2 group. It shows a potent nicotinic activity and a significant difference in conformation as compared with acetylcholine. In the crystal structure the anions are oriented stereospecifically with respect to the tetrahedron of the quaternary ammonium group. The geometry of two triangles formed by the quaternary nitrogen atom, the oxygen atom of the carbonyl group, and by either of the two anions nearest to the quaternary ammonium group is characteristic for the nicotinic activity of 1.

scholarly journals Crystal Structure of a Cationic Bile Salt Derivative ([3,5,7,12]-3-(2-naphthyloylamino)-7,12-dihydroxycholan-24-triethylammonium iodide)

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 135
Author(s):  
Francisco Meijide ◽  
María Pilar Vázquez-Tato ◽  
Julio Seijas ◽  
Santiago de Frutos ◽  
Juan V. Trillo Novo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Quaternary Ammonium ◽  
Electrostatic Interactions ◽  
Amide Bond ◽  
Orthorhombic Space Group ◽  
Steroid Nucleus ◽  
Quaternary Ammonium Group ◽  
Group A ◽  
Hydroxy Groups

The crystal structure of the iodide salt of a quaternary ammonium derivative of cholic acid having a naphthalene group attached to the 3rd position of the steroid nucleus through an amide bond ([3,5,7,12]-3-(2-naphthyloylamino)-7,12-dihydroxycholan-24-triethylammonium iodide) has been resolved. The compound crystallizes in the P212121 orthorhombic space group (a/Å = 10.9458(3); b/Å = 12.1625(3); c/Å = 28.4706(7)). The lateral chain adopts a fully extended tttt conformation because the quaternary ammonium group cannot participate in the formation of hydrogen bonds. The iodide ion is involved in the formation of hydrogen bonds as well as the amide group and the two steroid hydroxy groups. Hirshfeld surface analysis confirms that these contacts, as well as the electrostatic interactions, stabilize the structure. The helixes around the 21 screw axis are right-handed ones.

The structure of vitamin B 12 . VIII. The crystal structure of vitamin B 12 -5'-phosphate

1970 ◽  
Vol 318 (1533) ◽  
pp. 143-167 ◽  
Keyword(s):  
Crystal Structure ◽  
Phosphate Ester ◽  
Water Molecules ◽  
Vitamin B ◽  
X Ray Diffraction ◽  
Fourier Synthesis ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Vitamin B 12 ◽  
Difference Fourier

The crystal structure of vitamin B 12 -5' -phosphate, a biosynthetic precursor of vitamin B 12 , has been determined by X-ray diffraction methods. The air-dried crystals are orthorhombic, space group P 2 1 2 1 2 1 , with a = 23.72 Å, b = 21.74 Å and c = 16.07 Å. The observed density of 1.362 g cm -3 indicates four vitamin B 12 -5' -phosphate and about sixty water molecules in the unit cell. The X-ray diffraction data to 1.2 Å resolution were collected with a PAILRED linear diffractometer using Cu K α radiation from a silicon monochromator. The structure was solved by using Patterson methods in conjunction with the tangent formula and was refined by Fourier and least-squares methods. The final R value for the 2112 observed reflexions is 16.2 %. The structure is very similar to that found by Hodgkin and co-workers for air-dried vitamin B 12 crystals. The difference Fourier synthesis between this compound and vitamin B 12 shows that two water molecules move into phosphate oxygen positions when the phosphate in the precursor is removed, and one acetamide in contact with these water molecules in the vitamin is rotated out of the way in the phosphate. A second acetamide is also differently oriented in the two crystals. The α -glycosidic bond between the ribose and the dimethylbenzimidazole is 16° out of the plane of the base. The ribose conformation is C2'>- exo , and the phosphate ester conformations are similar to those found in other B 12 crystals.

Metamunirite, a new anhydrous sodium metavanadate from San Miguel County, Colorado

1991 ◽  
Vol 55 (381) ◽  
pp. 509-513 ◽  
Author(s):  
Howard T. Evans
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Fibre Axis ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Sodium Metavanadate

AbstractMetamunirite, β-NaVO3, is found in cavities in sandstone in San Miguel County, Colorado, occurring as fine, fibrous, colourless needles. X-ray powder and precession photographs show the crystals to be orthorhombic, space group Pnma, with a = 14.134(7), b = 3.648(2), c = 5.357(2) Å. They are optically biaxial positive with nα = 1.780(2) (‖c), nβ = 1.800(2) (‖a), nγ ≫ 185 (‖b, fibre axis; positive elongation), 2Vz moderate. A crystal structure analysis, confirming the previously determined structure of β-NaVO3, shows the presence of (VO3)n chains made up of zig-zag VO5 square pyramids. Metamunirite is probably formed by dehydration of munirite, NaVO3.2H2O.

scholarly journals Preparative-scale HPLC Resolution of Metallacyclic η3-Allyltricarbonyliron Complexes and Determination of the Absolute Configuration by X-Ray Crystal Structure Analysis

1999 ◽  
Vol 23 (9) ◽  
pp. 578-579
Author(s):  
Rainer Schobert ◽  
Hermann Pfab ◽  
Jutta Böhmer ◽  
Frank Hampel ◽  
Andreas Werner
Keyword(s):  
Crystal Structure ◽  
Silica Gel ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
Preparative Scale ◽  
X Ray ◽  
The Absolute

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.

scholarly journals Crystal structure of pimecrolimus Form B, C43H68ClNO11

2021 ◽  
Vol 36 (1) ◽  
pp. 35-42
Author(s):  
Shivang Bhaskar ◽  
Joseph T. Golab ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Density Functional ◽  
Van Der Waals Interactions ◽  
Powder Diffraction File ◽  
X Ray ◽  
Weak Intermolecular Interactions ◽  
Significant Difference ◽  
Atomic Coordinates ◽  
Solid State Conformation

The crystal structure of pimecrolimus Form B has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Pimecrolimus crystallizes in the space group P21 (#4) with a = 15.28864(7), b = 13.31111(4), c = 10.95529(5) Å, β = 96.1542(3)°, V = 2216.649(9) Å3, and Z = 2. Although there are an intramolecular six-ring hydrogen bond and some larger chain and ring patterns, the crystal structure is dominated by van der Waals interactions. There is a significant difference between the conformation of the Rietveld-refined and the DFT-optimized structures in one portion of the macrocyclic ring. Although weak, intermolecular interactions are apparently important in determining the solid-state conformation. The powder pattern is included in the Powder Diffraction File™ (PDF®) as entry 00-066-1619. This study provides the atomic coordinates to be added to the PDF entry.

Second-Generation Inhibitors for the Metalloprotease Neprilysin Based on Bicyclic Heteroaromatic Scaffolds: Synthesis, Biological Activity, and X-Ray Crystal-Structure Analysis

2005 ◽  
Vol 88 (4) ◽  
pp. 731-750 ◽  
Author(s):  
Stefan Sahli ◽  
Brian Frank ◽  
W. Bernd Schweizer ◽  
François Diederich ◽  
Denise Blum-Kaelin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biological Activity ◽  
Structure Analysis ◽  
Second Generation ◽  
Crystal Structure Analysis ◽  
X Ray

Crystal structure of the anticancer drug carmustine determined by X-ray powder diffraction

2021 ◽  
pp. 1-3
Author(s):  
Carina Schlesinger ◽  
Edith Alig ◽  
Martin U. Schmidt
Keyword(s):  
Crystal Structure ◽  
Anticancer Drug ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Powder Diffraction Data ◽  
Orthorhombic Space Group ◽  
Commercial Sample ◽  
One Dimensional ◽  
X Ray ◽  
Hydrogen Bond Pattern

The structure of the anticancer drug carmustine (1,3-bis(2-chloroethyl)-1-nitrosourea, C5H9Cl2N3O2) was successfully determined from laboratory X-ray powder diffraction data recorded at 278 K and at 153 K. Carmustine crystallizes in the orthorhombic space group P212121 with Z = 4. The lattice parameters are a = 19.6935(2) Å, b = 9.8338(14) Å, c = 4.63542(6) Å, V = 897.71(2) ų at 153 K, and a = 19.8522(2) Å, b = 9.8843(15) Å, c = 4.69793(6) Å, V = 921.85(2) ų at 278 K. The Rietveld fits are very good, with low R-values and smooth difference curves of calculated and experimental powder data. The molecules form a one-dimensional hydrogen bond pattern. At room temperature, the investigated commercial sample of carmustine was amorphous.

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