- N-Glycosyl-thiophene-2-carboxamides: Effects on endothelial cell growth in the presence and absence of bFGF - A significant increase in potency using per-O-acetylated sugar analogues
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Inhibitors of endothelial cell proliferation are of interest in development of therapies for angiogenesis related disease. N-Glucosyl-thiophene-2- carboxamides have been synthesized and evaluated for their effects on proliferation in bovine aortic endothelial cells. Per-O-acetylated-N-glucosyl- thiophene-2-carboxamides showed improved inhibition of both serum and bFGF stimulated uptake of [3H]thymidine, when compared to non-acetylated analogues.
- Rawe, Sarah L.,Zaric, Violeta,O'Boyle, Kathy M.,Murphy, Paul V.
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- N-Glycosyl-thiophene-2-carboxamides: synthesis, structure and effects on the growth of diverse cell types
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A range of N-glycosyl-thiophene-2-carboxamides, including a 6H-thieno[2,3-c]pyridin-7-one and a bivalent compound, have been synthesised and assayed for their effects on DNA synthesis in bovine aortic endothelial cells or on the growth of synoviocytes. Per-O-acetylated analogues of the glycoconjugates were significantly more effective inhibitors when compared to their corresponding non-acetylated analogues, indicating that the lower potency observed for hydroxylated derivatives is due to less efficient transport of these compounds across the cell membrane. Thiophene-2-carboxamide was inactive as an inhibitor of bFGF induced proliferation, confirming the requirement of the carbohydrate residue for the observed biological properties. Glucose, mannose, galactose and 2-amino-2-deoxy-glucose analogues were active as were a variety of substituted thiophene derivatives; the 6H-thieno[2,3-c]pyridin-7-one conjugate was inactive. Conformational analysis of the title compounds was investigated. X-ray crystal structural analysis of four N-glucosyl-thiophene-2-carboxamides showed that the pyranose rings adopted the expected 4C1 conformations and that Z-anti structures were predominant (H1-C1-N-H anomeric torsion angle varied from -168.2° to -175.0°) and that the carbonyl oxygen and sulfur of the thiophene adopted an s-cis conformation in three of the isomers. In a crystal structure of a 3-alkynyl derivative, the hydrogen atom of the NH group was directed toward the acetylene group. The distance between the hydrogen atom and acetylene carbons and angles between nitrogen, hydrogen and carbon atoms were consistent with hydrogen bonding and this was supported by IR and NMR spectroscopic studies. The geometries of thiophene-2-carboxamides were explored by density functional theory (DFT) and Moller-Plesset (MP2) calculations and the s-cis conformer of thiophene-2-carboxamide was found to be more stable than its s-trans isomer by 0.83 kcal mol-1. The s-cis conformer of 3-ethynyl-thiophene-2-carboxamide was 5.32 kcal mol-1 more stable than the s-trans isomer. The larger stabilisation for the s-cis conformer in the 3-alkynyl derivatives is explained to be due to a moderate hydrogen bonding interaction between the alkyne and NH group.
- Rawe, Sarah L.,Doyle, Dearbhla,Zaric, Violeta,Rozas, Isabel,McMahon, Kevin,Tosin, Manuela,Bunz, Helge Mueller,Murphy, Evelyn P.,O' Boyle, Kathy M.,Murphy, Paul V.
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p. 1370 - 1390
(2007/10/03)
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- Liquid Crystalline Compounds in the Thiophene Series, Part 11. Liquid Crystalline Thiophene Carboxylic Esters
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The new series of ten 4,4'-bis(5-alkyl-2-thienylcarbonyloxy)azobenzenes (2a-2j) and ten 2,5-bis(5-alkyl-2-thienylcarbonyloxy)toluenes (3a-3j) were prepared.These, as yet unknown esters were characterized in relation to their structures by elemental analyses, IR, UV, 1H NMR spectra and MS.The azobenzene-esters 2a-2j which form liquid crystalline phases were studied by microscopy under polarized light and DSC (differential scanning calorimetry).Through the observation of the optical textures nematic phases were monitored.Only 2j has an additional smectic phase; 2h and 2i form monotropic smectic phases during cooling.The toluene-esters 3a-3j do not form liquid crystalline phases. - Keywords: Liquid Crystalline Thiophene Derivatives; Thiophene Carboxylic Esters; Mesogenic Groups; Liquid Crystalline Esters; Liquid Crystalline Azobenzene Derivatives
- Kossmehl, Gerhard,Hirsch, Barbara
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p. 1265 - 1274
(2007/10/03)
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- Liquid Crystalline Compounds in the Thiophene Series. 1. Liquid Crystalline Thiophene Carboxylic Esters
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Carboxylic esters have been prepared from 5-alkyl-2-thiophenecarboxylic acid and hydrochinone, biphenol, respectively cholesterol as well as one ester from 2,5-thiophene dicarboxylic acid and p-ethylphenol.Only the esters from biphenol respectively cholesterol have liquid crystalline phases. - Keywords: Liquid Crystalline Thiophene Derivatives, Thiophene Carboxylic Esters
- Kossmehl, Gerhard,Budwill, Detlev
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p. 1669 - 1677
(2007/10/02)
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