0000000000060097

AUTHOR

Christian Peifer

(3RS,1SR)-3-Bromo-3-(1-phenylpropyl)chroman-2,4-dione

The title compound, C18H15BrO3, was obtained by bromination of phenprocoumone with N-bromo­succin­imide. The X-ray structure confirms an earlier proposal concerning the regioselectivity of the reaction to introduce the Br atom at the 3-position.

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Ethyl (2,3-dihydro-1H,1′H-2,3′-biindol-1-yl)glyoxylate

The crystal structure of the title compound, C20H18N2O3, was determined in the course of our studies of the synthesis of 3-acylindole derivatives. We obtained it as an unexpected racemic side product. The crystal structure contains chains of dimers along the a axis.

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(1aR,2aS,5aS,5bS)-Perhydro-4H-oxireno[3,4]cyclopenta[1,2-b]furan-4-one

The structure of the title compound, C7H8O3, was determined in the course of our studies of the synthesis of cyclopenta[1,2-b]furan-4-one derivatives. The molecule has four chiral C atoms. The X-ray crystal structure analysis shows the compound to possess an epoxide group with an endo orientation with respect to the lactone group.

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4-[5-(4-Fluorophenyl)-3-isopropylisoxazol-4-yl]pyridin-2(1H)-one

The crystal structure of the title compound, C17H15FN2O2, was determined as part of a study of the biological activity of pyridine-substituted isoxazole derivatives as mitogen-activated protein kinase (MAPK) inhibitors. In the crystal structure of the title compound, the compound exists in the lactam and not in the tautomeric pyridin-2-ol form. As the aromatic pyridine nitrogen is considered to be important for accepting a hydrogen bond from p38MAPK, the structure of the lactam unit is correlated with the loss of biological activity of the title compound in the p38MAPK assay. In the crystal structure, the lactam is involved in hydrogen bonds, forming chains along the b axis.

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2-[(1-Methyl-1H-pyrrol-2-yl)carbonyl-meth-yl]isoindoline-1,3-dione.

The asymmetric unit of the title compound, C15H12N2O3, contains two almost identical molecules forming an nearly C2-symmetric dimeric pattern. The dihedral angles between the pyrrole ring and the phthalimide unit are 82.95 (8) and 86.57 (8)° for the two molecules. Within such a dimer, the phthalimide units of the two molecules form a dihedral angle of 1.5 (5)°.

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5,6,7-Trimethoxy-2,3-dihydro-1H,8H-benzo[a]pyrrolo[3,4-c]carbazole-1,3-dione dimethyl sulfoxide solvate

The crystal structure of the title compound, C21H16N2O5·C2H6OS, was determined to investigate the electrocyclic reactivity of 3,4-di­aryl-1H-pyrrole-2,5-diones (3,4-bisarylmal­eimides) to the yield corresponding carbazole derivatives.

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3-(4-Fluorophenyl)-4-(4-pyridyl)quinolin-2(1H)-one

The title compound, C20H13FN2O, has the quinolin-2(1H)-one unit in the lactam form. The mol­ecules form rows along the b axis via N—H⋯N hydrogen bonds

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From Five- to Six-Membered Rings:  3,4-Diarylquinolinone as Lead for Novel p38MAP Kinase Inhibitors

In this study we describe the design, synthesis, and biological evaluation of 3-(4-fluorophenyl)-4-pyridin-4-ylquinoline-2(1H)-one (5) as a new inhibitor of MAPK with a p38alphaMAPK IC50 of 1.8 muM. By keeping the common vicinal pyridine/4-F-phenyl pharmacophore, such as in prototypical imidazole 20 or isoxazole 13 but in 5 connected to the six-membered quinoline core, we were particularly interested in comparing biological activity, details of molecular geometry, and different binding modes of these compounds. Compounds 20 and 13 were active both in the p38alpha- and JNK3-assay, whereas 5 was selective for p38alpha, with no JNK3 inhibition. By comparing the X-ray structures of the compound…

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4-(3-Hydroxy-4-methoxyphenyl)-3-(3,4,5-trimethoxyphenyl)-2,5-dihydro-1H-pyrrole-2,5-dione

The title compound, C20H19NO7, crystallizes in the space group Pna21. X-ray analysis shows the compound has the desired 3′-hydroxy and 4′-methoxy substitution pattern, as in the natural template combretastatin A-4.

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Partial Methylation at Am100 in 18S rRNA of Baker's Yeast Reveals Ribosome Heterogeneity on the Level of Eukaryotic rRNA Modification

Ribosome heterogeneity is of increasing biological significance and several examples have been described for multicellular and single cells organisms. In here we show for the first time a variation in ribose methylation within the 18S rRNA of Saccharomyces cerevisiae. Using RNA-cleaving DNAzymes, we could specifically demonstrate that a significant amount of S. cerevisiae ribosomes are not methylated at 2'-O-ribose of A100 residue in the 18S rRNA. Furthermore, using LC-UV-MS/MS of a respective 18S rRNA fragment, we could not only corroborate the partial methylation at A100, but could also quantify the methylated versus non-methylated A100 residue. Here, we exhibit that only 68% of A100 in t…

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Methyl [4-methoxy-3-(methylsulfonyloxy)benzoyl]formate

The crystal structure of the title compound, C11H12O7S, confirms an earlier proposal concerning the regioselectivity of electrophilic substitution reactions of mesyl guaiacol.

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Profile and molecular modeling of 3-(indole-3-yl)-4-(3,4,5-trimethoxyphenyl)-1 H-pyrrole-2,5-dione (1) as a highly selective VEGF-R2/3 inhibitor.

We report on selectivity profiling of 1 in a panel of 20 protein kinases and molecular modeling indicating 1 to be highly active and selective for VEGF-R2/3. Sequence alignment analysis and detailed insights into the ATP binding pockets of targeted protein kinases from the panel result in a unique structural architecture of VEGF-R2 mainly caused by the hydrophobic pocket I, determining the molecular basis for activity and selectivity of 1.

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Design, Synthesis, and Biological Evaluation of 3,4-Diarylmaleimides as Angiogenesis Inhibitors

The new analogue 2 of combretastatin A-4 was discovered to be an inhibitor of tubulin polymerization with an IC50 of 7.6 microM and reduced angiogenesis in the in vivo chick embryo model. Interestingly, in a series of 2,3-diarylmaleimides closely related to this lead, no other compound was found to be active in the tubulin polymerization assay. However, by screening in the in vivo chick embryo assay 10 was identified as a potent angiogenesis inhibitor indicating an alternative target. Indeed, molecular modeling studies suggest a reasonable binding mode of 10 at the ATP-binding site of the model kinase CDK2. Motivated by these results, analogues of 10 were screened for inhibitory activity in…

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3-(1H-Indol-3-yl)-4-(3,4,5-trimethoxyphenyl)-2,5-dihydro-1H-pyrrole-2,5-dione

The crystal structure of the title compound, C21H18N2O5, was determined in order to study the electrocyclic reactivity of 3,4-di­aryl-1H-pyrrole-2,5-dione derivatives. Intermolecular hydrogen bonds form sheets.

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(2aRS,3RS,4aSR,6aRS,6bSR)-3-Hydroxy-2a,3,4a,6,6a,6b-hexahydro-1,4-dioxacyclopenta[cd]pentalen-2(5H)-one

The mol­ecular structure of the title compound [enanti­omers (VIII) and (VIIIa)], C8H10O4, was determined in the course of our studies on the synthesis of cyclo­penta­[1,2-b]furan-4-one derivatives. Tricyclic (VIIIa) consists of a planar bridged lactone unit and the two other ring systems in the envelope conformation. It contains five chiral C atoms and was obtained as a racemic mixture. The X-ray analysis showed the compound to possess a half-acetal unit with an endo orientation of the half-acetal ether bridge with respect to the lactone unit.

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4-[5-(4-Fluorophenyl)-3-isopropylisoxazol-4-yl]pyridine

In the title compound, C17H15FN2O, the exocyclic bond angles at the C atoms of the isoxazole ring bearing the pyridyl and 4-fluoro­phenyl substituents are 129.66 (17) and 134.58 (16)°, respectively. The structure was determined in a study of the mol­ecular geometry of isoxazole derivatives with biological activity as MAPK inhibitors.

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2-(6-Methoxy-7H-purin-7-yl)-1-phenylethanone monohydrate

The crystal structure of the title compound, C14H12N4O2·H2O, was determined in the course of our studies of the synthesis and optimization of 7-aryl-7H-purines as inhibitors of the vascular endothelial growth factor receptor (VEGF-R), c-Jun NH2-terminal protein kinase 3 (JNK3) and the p38α mitogen-activated protein kinase (MAPK). In the title compound, two mol­ecules are associated with each other through O—H⋯N hydrogen bonds to different N atoms in the purine ring system. The compound was prepared via a regioselective synthesis using the meth­yl(aqua)cobaloxime complex, CH3Co(DH)2OH2, as a temporary auxiliary. The X-ray crystallographic results confirmed the regioselective N-7 alkyl­ation …

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3,4-Bis(4-fluorophenyl)-1,2,5-oxadiazole 2-oxide

The title compound, C14H8F2N2O2, also known as di(4-F-phen­yl)furazan N-oxide, was found as a side product in the synthesis of isoxazole derivatives. The are two molecules in the asymmetric unit. The bond length of the dipolar N—O unit is 1.107 (7) A. X-ray analysis confirmed the compound to have the desired structure

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2,2-Dimethyl-N-[3-(3,4,5-trimethoxybenzoyl)pyridin-4-yl]propanamide

The title compound, C20H24N2O5, was found to have an intra­molecular N—H⋯O bond with an N⋯O distance of 2.646 (2) A. In the crystal structure, mol­ecules form dimers along the c axis by aromatic stacking inter­actions. The X-ray crystallographic analysis was carried out to correlate the solid-state geometry with virtual structural information obtained by modelling.

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N-{(Z)-2-[1-(Triisopropylsilyl)-1H-indol-3-yl]-2-(triisopropylsilyloxy)vinyl}-2-(3,4,5-trimethoxyphenyl)acetamide

The molecular structure of the title compound, C39H62N2O5Si2, obtained as an unexpected side product, was determined in the course of our studies on the synthesis of N-triisopropyl-1H-indol-3-yl derivatives. Interestingly, although the triisopropylsilyl group was intended as a temporary protecting group, the compound comprises a remarkably stable N—Si bond. The vinyl C=C double bond possesses a Z configuration.

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3-(4-Fluorophenyl)-1-methyl-4-(4-pyridyl)quinolin-2(1H)-one

The title compound, C21H15FN2O, was synthesized in the course of our studies of p38 mitogen-activated protein kinase inhibitors. It has been investigated by 1H and 13C NMR spectroscopy and was proven by X-ray crystallographic analysis to be the N-methyl rather than the O-methyl isomer. In the crystal structure, a three-dimensional network is formed consisting of quinolinone aromatic stacking inter­actions and weak C—H⋯O and C—H⋯N hydrogen bonds.

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(4R)-4-Hydroxy-1-[(2S)-2-hydroxydodecyl]-L-proline monohydrate

The title compound, C17H33NO4·H2O, was found to be the S diastereoisomer with respect to the asymmetric C atom at the OH group on the chain. The X-ray structure was determined as part of a study of the mol­ecular geometry and stereochemistry of l-proline derivatives for pre-coating thin-layer chromatography plates intended for enantiomeric separation.

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4-[3-(4-Fluorophenyl)-5-isopropylisoxazol-4-yl]pyridine

The mol­ecular structure of the title compound, C17H15FN2O, was determined in the course of our studies on mitogen-activated protein kinase inhibitors. The exocyclic bond angles at the carbon atoms of the isoxazole ring bearing the pyridyl and 4-fluoro­phenyl rings are 130.0 (2) and 129.2 (2)°, respectively. The pyridine and 4-fluoro­phenyl rings are twisted relative to the isoxazole ring by 80.2 (2) and 19.1 (1)°, respectively.

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3,4-Diarylmaleimides Effectively Inhibit Proliferation of FLT3-ITD-Positive Leukemic Cells, Induce Apoptosis and Show Additive Effects in Combination with Chemotherapeutic Drugs.

Abstract Internal tandem duplication (ITD) mutations of FLT3 are present in leukemic blasts of approximately 30% of AML patients. ITD-mutations of FLT3 confer a worse prognosis and decreased overall survival. Therefore, FLT3-tyrosine kinase is considered an attractive drug target in AML and several FLT3-tyrosine kinase inhibitors (TKIs) are currently being tested in clinical trials (CEP701, MLN518, Sorafenib, PKC412). However, using these drugs as monotherapy, against the setting of remarkable efficacy has emerged the problem of short duration of remission indicating rapid development of secondary resistance. In addition, up to 30% of patients may show primary resistance to currently availa…

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rac-(3E,3aR,6aR)-3-(Hydroxymethylene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one

The crystal structure of the title compound, C8H8O3, was determined in the course of our studies of the synthesis of cyclo­penta­[1,2-b]furan-4-one derivatives. The title compound has two chiral C atoms and was obtained as a racemic mixture. It was found to possess a vinylogous acid group with an E configuration at the double bond. The compound exists in the hydroxy­methyl­ene and not in the tautomeric carbaldehyde form. The asymmetric unit consists of two molecules.

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