Derivatives of 1,3,5-Triamino-1,3,5-trideoxy-cis-inositol as Versatile Pentadentate Ligands for Protein Labeling with Re-186/188. Prelabeling, Biodistribution, and X-ray Structural Studies

1998 ◽  
Vol 9 (6) ◽  
pp. 691-702 ◽  
Author(s):  
Andreas Kramer ◽  
Roger Alberto ◽  
André Egli ◽  
Ilse Novak-Hofer ◽  
Kaspar Hegetschweiler ◽  
...  
Keyword(s):  
Protein Labeling ◽  
Structural Studies ◽  
X Ray ◽  
Pentadentate Ligands ◽  
Derivatives Of

Structural studies on monofluorinated derivatives of the phytohormone indole-3-acetic acid (auxin)

1996 ◽  
Vol 52 (4) ◽  
pp. 651-661 ◽  
Author(s):  
A. Antolić ◽  
B. Kojić-Prodić ◽  
S. Tomić ◽  
B. Nigović ◽  
V. Magnus ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Side Chain ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Molecular Conformations ◽  
X Ray ◽  
Structure Activity ◽  
Planar Conformation ◽  
Derivatives Of ◽  
Indole 3 Acetic Acid

As part of the molecular recognition studies on the phytohormone indole-3-acetic acid (IAA) a series of fluorinated IAA's has been examined. The phenyl ring substitution at positions 4, 5, 6 and 7 resulted in four compounds, which were analyzed. Structure–activity correlation includes the analysis of their molecular conformations, based on the X-ray diffraction and computational chemistry results, and bioactivity determinations in the Avena coleoptile and the Pisum sativum stem straight-growth tests, lipophilicity and UV absorbance. The conformations of monofluorinated IAA's and a free hormone are defined by rotations about two bonds: one describes the relative orientation of a side chain towards the indole plane and the second the orientation of the carboxylic group. The results of X-ray structure analysis revealed the folded shape of the molecules in all compounds studied. Molecular mechanics and dynamics located the folded conformation as the local minimum, but failed to detect the planar conformation as one of the local minima, which according to ab initio results on IAA and 4-CI-IAA could also be possible. Crystal data at 295 K for 4-F-IAA and at 297 K for 5-F-IAA, and at 100 K for 6-F-IAA and 7-F-IAA using Mo Kα radiation (λ = 0.71073 Å) and Cu Kα (λ = 1.5418 Å, for 7-F-IAA), are as follows: 4-F-IAA, C10H8NO2F, Mr = 193.18, monoclinic, C2/c, a = 17.294 (5), b = 13.875 (4), c = 7.442 (4) Å, β = 103.88 (6)°, V = 1734 (1) Å3, Z = 8, Dx = 1.480 g cm−3, μ = 1.1 cm−1, F(000) = 800, R = 0.043, wR = 0.044 for 823 symmetry-independent [I ≥ 3σ(I)] reflections; 5-F-IAA, C10H8NO2F, monoclinic, P21/c, a = 19.284 (5), b = 5.083 (4), c = 9.939 (4) Å, β = 117.28 (6)°, V = 865.9 (1) Å3, Z = 4, Dx = 1.482 g cm−3, μ = 1.1  cm−1, F(000) = 400, R = 0.062, wR = 0.057 for 729 symmetry-independent [I ≥ 3σ(I)] reflections; 6-F-IAA, C10H8NO2F, monoclinic, P21/a, a = 9.360 (1), b = 5.167 (4), c = 17.751 (4) Å, β = 93.75 (1)°, V = 856.7 (8) Å3, Z = 4, Dx = 1.498 g cm−3, μ = 1.1 cm−1, F(000) = 400, R = 0.048, wR = 0.048 for 1032 symmetry-independent [I ≥ 2σ(I)] reflections; 7-F-IAA, C10H8NO2F, monoclinic, P21/a, a = 9.935 (5), b = 5.0059 (4), c = 17.610 (1) Å, β = 102.13 (1)°, V = 856.3 (1) Å3, Z = 4, Dx = 1.498 g cm−3, μ = 9.8 cm−1 (Cu Kα, F(000) = 400, R = 0.035, wR = 0.040 for 1504 symmetry-independent [I ≥ 2σ(I)] reflections.

Molecular structure and substituent electronic effects in 10-arylidenanthrones-9

2000 ◽  
Vol 215 (5) ◽  
Author(s):  
O.V. Shishkin ◽  
A.Yu. Kovalevsky ◽  
M. Yu. Antipin ◽  
Z.N. Tarakhno
Keyword(s):  
Gas Phase ◽  
Phenyl Group ◽  
Conformational Flexibility ◽  
Am1 Method ◽  
Equilibrium Geometry ◽  
Boat Conformation ◽  
Structural Studies ◽  
Electronic Effects ◽  
X Ray ◽  
Derivatives Of

X-ray structural studies of derivatives of 10-arylidenanthrone-9 containing π-electron donating and withdrawing substituents within arylidene fragment have been carried out. In the crystal the molecules are strongly disflattened with the central dihydrocycles adopting an asymmetric boat conformation. This geometry of the molecules is a result of unfavourable non-valence interactions between atoms at the C=C bond and the hydrogens at the peri-positions of the anthraquinone fragment. Calculations performed by the semiempirical quantum-chemical AM1 method demonstrate that in the gas phase equilibrium geometry of the molecules was similar to that in the crystal. It was shown as well that the central dihydrocycle possesses high conformational flexibility in spite of steric overcrowding in all of the compounds. Electronic effects of the substituents had significant influence only on the arylidene moiety, resulting in different rotation angles of the phenyl group around the C=C exocyclic bond and virtually no effect on the anthraquinone part of the molecules.

Synthetic and x-ray structural studies on pentabenzylcyclopentadienyl derivatives of manganese, rhenium, and iron

1989 ◽  
Vol 8 (3) ◽  
pp. 816-821 ◽  
Author(s):  
Marvin D. Rausch ◽  
Woei Min. Tsai ◽  
John W. Chambers ◽  
Robin D. Rogers ◽  
Helmut G. Alt
Keyword(s):  
Structural Studies ◽  
X Ray ◽  
Derivatives Of

Dialkyldithiocarbamate derivatives of toluene-3,4-dithiolato arsenic(III) and -bismuth(III): synthetic, spectral and single crystal X-ray structural studies

Polyhedron ◽  
2005 ◽  
Vol 24 (1) ◽  
pp. 89-95 ◽  
Author(s):  
H.P.S. Chauhan ◽  
Kavita Kori ◽  
Nagulu Meera Shaik ◽  
Sanjay Mathur ◽  
Volker Huch
Keyword(s):  
Single Crystal ◽  
Structural Studies ◽  
X Ray ◽  
Derivatives Of

Structural studies in the iron(III)/chloride/α,α'-diimine system. II. Ionic derivatives of stoichiometry FeCl3(phen,bpy)1,1.5

1983 ◽  
Vol 36 (10) ◽  
pp. 2043 ◽  
Author(s):  
BN Figgis ◽  
JM Patrick ◽  
PA Reynolds ◽  
BW Skelton ◽  
AH White ◽  
...  
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Crystal Structures ◽  
Acetonitrile Solution ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Determinations ◽  
Derivatives Of

The crystal structures of the 1 : 1 adducts of FeCl3 with 2,2'-bipyridine (bpy) (1) and 1,10-phenanthroline (phen) (2), as recrystallized from nitromethane, have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least squares to residuals of 0.038 and 0.032 for 1341 and 3968 'observed' reflections; the result for (2) is a redetermination. Crystals of (1) are orthorhombic, Pbnb, a 15.013(4), b 13.510(5), c 12.471(3) Ǻ, Z 4. Crystals of (2) are triclinic, P1, a 15.823(5), b 11.021(5), c 8.200(3) Ǻ, α 80.27(3), β 76.78(3), γ 89.64(3)°, Z 2. Both complexes haw the stoichiometry (FeCl3)1(bpy,phen)1, but are formulated as cis-[Fe(bpy,phen)2Cl2] [FeCl4]; in both compounds, the Fe-N distance is c. 2.20, (trans to Cl), 2.1, Ǻ(cis to Cl), while Fe-Cl, c. 2.2, Ǻ, is short. The structure determinations of Fe2Cl6(phen,bpy)3 as [Fe(phen)2Cl2]+ [Fe(phen)Cl4]- (3) and [Fe(bpy)2Cl2]+ [Fe(bpy)Cl4]- (4) are also reported. Compound (3) (from acetonitrile solution) is triclinic, P1, a 16.502(5), b 11.857(3), c 10.653(3) Ǻ, α 84.92(2), β 72.66(2), γ 74.80(2)°, Z 2, and was refined to a residual of 0.034 for 5540 'observed' reflections. The cation geometry is similar to that of (2); in the anion, the two Fe-CI bonds trans to each other are long [2.377(1) and 2.365(1) Ǻ] while those trans to the Fe-N bonds are short [2.287(1) and 2.318(1) Ǻ]. Fe-N distances are 2.216(3) and 2.220(3) A. Compound (4) (as its nitromethane solvate) is also triclinic, P1, a 14.480(7), b 12.645(5), c 10.678(4) Ǻ, α 95.68(3), β 109.21(3), γ 9258(3)°, Z 2; a residual of 0.042 was obtained for 4962 'observed' reflections. Cation and anion metal geometries are similar to those of (3).

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

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