scholarly journals Characterization of two new degradation products of atorvastatin calcium formed upon treatment with strong acids

2019 ◽  
Vol 15 ◽  
pp. 2085-2091
Author(s):  
Jürgen Krauß ◽  
Monika Klimt ◽  
Markus Luber ◽  
Peter Mayer ◽  
Franz Bracher
Keyword(s):  
Degradation Products ◽  
Crystal Structure Analysis ◽  
Side Chain ◽  
The Novel ◽  
Isopropyl Group ◽  
X Ray ◽  
Atorvastatin Calcium ◽  
Acidic Conditions ◽  
Strong Acids

Atorvastatin calcium (Lipitor®, Sortis®) is a well-established cholesterol synthesis enzyme (CSE) inhibitor commonly used in the therapy of hypercholesterolemia. This drug is known to be sensitive to acid treatment, but only little data has been published on the structures of the degradation products. Here we report the identification of two novel degradation products of atorvastatin, which are formed only under drastic acidic conditions. While treatment with conc. sulfuric acid led to a loss of the carboxanilide residue (accompanied by an expectable lactonization/dehydration process in the side chain), treatment with conc. aqueous hydrochloric acid gave a complex, bridged molecule under C–C-bond formation of the lactone moiety with the pyrrole, migration of the isopropyl group and loss of the carboxanilide residue. The novel degradation products were characterized by NMR spectroscopy, HRMS data and X-ray crystal structure analysis.

scholarly journals Characterization of two new degradation products of atorvastatin-calcium formed upon treatment with strong acids

2019 ◽  
Author(s):  
Jürgen Krauß ◽  
Monika Klimt ◽  
Markus Luber ◽  
Peter Mayer ◽  
Franz Bracher
Keyword(s):  
Degradation Products ◽  
Crystal Structure Analysis ◽  
Side Chain ◽  
The Novel ◽  
Isopropyl Group ◽  
X Ray ◽  
Atorvastatin Calcium ◽  
Acidic Conditions ◽  
Strong Acids

Atorvastatin-calcium (Lipitor®, Sortis®) is a well-established cholesterol synthesis enzyme (CSE) inhibitor commonly used in the therapy of hypercholesterolemia. This drug is known to be sensitive to acid treatment, but only little data has been published on the structures of the degradation products. Here we report on to the identification of two novel degradation products of atorvastatin, which are formed only under drastic acidic conditions. While treatment with conc. sulfuric acid lead to a loss of the carboxanilide residue (accompanied by an expectable lactonization/dehydration process in the side chain), treatment with conc. aqueous hydrochloric acid gave a complex, bridged molecule under, C,C-bond formation of the lactone moiety with the pyrrole, migration of the isopropyl group and loss of the carboxanilide residue. The novel degradation products were characterized by NMR spectroscopy, HR-MS data and X-ray crystal structure analysis.

Synthesis of the novel anions [Re3H3(μ3-OR)(CO)9]− (R = Et, i-Pr, t-Bu) and x-ray characterization of [Re3H3(μ3-OEt)(CO)9](NEt4

1981 ◽  
Vol 219 (2) ◽  
pp. C23-C25 ◽  
Author(s):  
Gianfranco Ciani ◽  
Giuseppe D'Alfonso ◽  
Maria Freni ◽  
Pierfrancesco Romiti ◽  
Angelo Sironi
Keyword(s):  
The Novel ◽  
X Ray

Synthesis and Characterization of Y2O3 Nanoflowers

2012 ◽  
Vol 465 ◽  
pp. 76-79 ◽  
Author(s):  
Shuang Zhan ◽  
Xia Li
Keyword(s):  
Fourier Transform ◽  
Phase Composition ◽  
Electron Microscope ◽  
Synthesis And Characterization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Scanning Electron

The novel Y2O3 nanoflowers were synthesized through a facile hydrothermal method without using any catalyst or template. The phase composition and the microstructure of as-prepared products were characterized by field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD) as well as Fourier transform infrared spectrum. The formation mechanism for the Y2O3 flowers has been proposed.

Selenium coronands. A novel conformational pair

1988 ◽  
Vol 66 (11) ◽  
pp. 2956-2958 ◽  
Author(s):  
B. Mario Pinto ◽  
Blair D. Johnston ◽  
Raymond J. Batchelor ◽  
Frederick W. B. Einstein ◽  
Ian D. Gay
Keyword(s):  
Nmr Spectra ◽  
Crystallographic Analysis ◽  
The Novel ◽  
Torsion Angles ◽  
X Ray ◽  
Structure Formula ◽  
Independent Molecules ◽  
Similar Conformation ◽  
C Nmr

The synthesis and characterization of the novel selenium coronands, 1,3,7,9-tetraselenacyclododecane 1a, 1,3,7,9,13,15-hexaselenacyclooctadecane 2a, the corresponding β-gem-dimethyl derivatives 1b, 2b, and 1,5,9,13-tetraselenacyclohexadecane 3, and 1,5,9,13,17,21-hexaselenacyclotetracosane 4 are described. X-ray crystallographic analysis of 1a reveals three independent molecules that exist in two distinct conformations, one molecule having approximate two-fold symmetry together with two molecules (of similar conformation) each having crystallographic [Formula: see text] symmetry. The conformations are denoted as [3333] or [66]. Whereas one resembles that of cyclododecane and tetrathia-12-crown-4 with respect to torsion angles, the other resembles that of tetraoxa-12-crown-4. The solid state CP-MAS 77Se and 13C nmr spectra are interpreted in light of the crystallographic information. Crystal structure: formula Se4C8H16; fw = 428.05; monoclinic, P21/c; Z = 8; a = 15.823(2) Å, b = 5.534(1) Å, c = 27.962(5) Å, β = 92.26(1)°; V = 2446.6 Å3; T = 200 K; R = 0.027 for 2162 observed data (I ≥ 2.5σ(I)).

A fourfold interpenetrating diamond-like three-dimensional zinc(II) coordination polymer: synthesis, crystal structure and physical properties

2019 ◽  
Vol 75 (5) ◽  
pp. 504-507 ◽  
Author(s):  
Hui-Ru Chen
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Three Dimensional ◽  
Fluorescence Emission ◽  
Crystal Structure Analysis ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metal Compounds ◽  
X Ray ◽  
Coordination Framework

Excellent fluorescence properties are exhibited by d 10 metal compounds. The novel three-dimensional ZnII coordination framework, poly[[{μ2-bis[4-(2-methyl-1H-imidazol-1-yl)phenyl] ether-κ2 N 3:N 3′}(μ2-furan-2,5-dicarboxylato-κ2 O 2:O 5)zinc(II)] 1.76-hydrate], {[Zn(C6H2O5)(C20H18N4O)]·1.76H2O} n , has been prepared and characterized using IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal structure analysis revealed that the compound exhibits a novel fourfold interpenetrating diamond-like network. This polymer also displays a strong fluorescence emission in the solid state at room temperature.

scholarly journals Synthesis and Characterization of Novel Ruthenium(III) Complexes with Histamine

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Jakob Kljun ◽  
Saša Petriček ◽  
Dušan Žigon ◽  
Rosana Hudej ◽  
Damijan Miklavčič ◽  
...  
Keyword(s):  
Cancer Treatment ◽  
Side Chain ◽  
Synthesis And Characterization ◽  
Medical Applications ◽  
Amino Group ◽  
Heterocyclic Derivative ◽  
Biological Assays ◽  
X Ray ◽  
Protonated Amino Group

Novel ruthenium(III) complexes with histamine[RuCl4(dmso-S)(histamineH)]⋅O(1a) and[RuCl4(dmso-S)(histamineH)](1b) have been prepared and characterized by X-ray structure analysis. Their crystal structures are similar and show a protonated amino group on the side chain of the ligand which is not very common for a simple heterocyclic derivative such as histamine. Biological assays to test the cytotoxicity of the compound1bcombined with electroporation were performed to determine its potential for future medical applications in cancer treatment.

X-ray crystal structure analysis of a bisepoxide derived from secologanin: the structure and absolute configuration

1983 ◽  
Vol 61 (2) ◽  
pp. 282-283 ◽  
Author(s):  
Stanley C. Nyburg ◽  
Pik Y. Siew ◽  
Gavin N. Saunders ◽  
John R. Purdy ◽  
Stewart McLean
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
Dimethyl Acetal ◽  
Crystal Structure Analysis ◽  
Side Chain ◽  
Bench Mark ◽  
Chemical Transformations ◽  
X Ray ◽  
Derivatives Of

The structure and absolute configuration of a bisepoxide (2) produced by oxidation of tetraacetylsecologanin dimethyl acetal (1) with m-chloroperbenzoic acid have been established by X-ray crystal structure analysis. Epoxidation of the vinyl side chain is unexceptional; epoxidation of the β-alkoxyacrylate moiety is novel. This determination represents a valuable bench mark for configurational assignments, since the bisepoxide has been correlated by chemical transformations with a number of synthetic and naturally-occurring derivatives of secologanin.

Isolation and X-ray characterization of a new crystal modification of Pd6(μ2-CO)6(μ-dppm)3 during the synthesis of the novel fluxional triangulo Pd(0) complex [Pd3(μ2-CO)3(dppm)2]n (n = 1 or 2)

Polyhedron ◽  
1997 ◽  
Vol 16 (16) ◽  
pp. 2789-2796 ◽  
Author(s):  
David G. Holah ◽  
Alan N. Hughes ◽  
Elizabeth Krysa ◽  
Robert T. Markewich ◽  
Matthew D. Havighurst ◽  
...  
Keyword(s):  
Crystal Modification ◽  
The Novel ◽  
X Ray
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