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Selected AbstractsQSAR Study of 2,3-Benzodiazepin-4(thi)one- and 1,2-Phthalazine-Related Negative Allosteric Modulators of the AMPA Receptor: A Structural Descriptors-Based ReassessmentMOLECULAR INFORMATICS, Issue 3 2005Peter Buchwald Abstract In an attempt to establish statistically more rigorous and chemically more meaningful quantitative structure-activity relationship (QSAR) equations, a reassessment of a recent study of in vivo anticonvulsant activity for a set of 2,3-benzodiazepin-4(thi)one- and 1,2-phthalazine-related allosteric AMPA antagonists (n=61) is presented. Contrary to the original, relatively nonspecific descriptor set, which included, for example, a number of topological descriptors, specific structural descriptors that are much easier to interpret from a medicinal chemical point of view are used in this multiple linear regression-based approach. Only statistically significant descriptors have been retained in the final equation, and whereas they give about the same correlation as those of the original paper on the training set (r2 of 0.79 vs. 0.76, n=49), they perform much better on the test set (predictive r of 0.73 vs. 0.05; r2 of 0.78 vs. 0.08, n=12). Descriptors found to be relevant are clearly related to substitutions at known pharmacophore positions, such as those corresponding to the 2,3-, 7,8- and 4,-positions of the benzodiazepine skeleton. Therefore, by a more careful selection of the descriptor set, both an improved prediction and a more intuitive quantitative interpretation could be achieved for this set of allosteric AMPA antagonists. [source] Synthesis and insecticidal activity of new 3-benzylfuran-2-yl N,N,N,,N,-tetraethyldiamidophosphate derivativesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2008Vanderlúcia F Paula Abstract BACKGROUND: A series of 3-benzylfuran-2-yl N,N,N,,N,-tetraethyldiamidophosphate derivatives were synthesized as potential new agents to control insects. Their structures were confirmed on the basis of IR, NMR and MS analyses. RESULTS: Ten 3-benzylfuran-2-ylN,N,N,,N,-tetraethyl derivatives were prepared from the compound furan-2-yl N, (N,N,N,,N,-tetraethyldiamidophosphate). The contact toxicity of all derivatives, at a dose of 10 µg mg,1 insect, was evaluated against four insect species, Ascia monuste orseis Latr. (Lepidoptera: Pyralidae), Diaphania hyalinata (L.) (Lepidoptera: Pyralidae), Sitophilus zeamais Mots. (Coleoptera: Bruchidae) and Solenopsis saevissima (Smith) (Hymenoptera: Formicidae). The mortality range observed for some derivatives, such as 3-(3-methylbenzyl)furan-2-yl N,N,N,,N,-tetraethyldiamidophosphate (82.5% mortality against D. hyalinata; 100% mortality against S. saevissima), was comparable with that of the commercial insecticide chlorpyrifos-methyl. The biological activity of the derivatives depended on the substitution pattern of the benzylic ring. Furan-2-yl N,N,N,,N,-tetraethyldiamidophosphate, furan-2-yl N,N -diethylamidochlorophosphate and difuran-2-yl N,N -diethylamidophosphate were also evaluated, displaying, in some cases, activity comparable with that of chlorpyrifos-methyl (90%, 100% and 97.5% respectively against A. monuste orseis). Considerable activity was observed for some furan-2(5H)-ones evaluated. CONCLUSION: Ten 3-benzylfuran-2-yl N,N,N,,N,-tetraethyldiamidophosphate derivatives were synthesized and fully characterized from a chemical point of view. The results obtained from the biological assays indicate that this class of compounds can be utilized for the design of new substances endowed with insecticidal activity. Copyright © 2008 Society of Chemical Industry [source] Topographical and Wettability Effects of Post-Discharge Plasma Treatments on Macroporous Polystyrene-Divinylbenzene Solid FoamsPLASMA PROCESSES AND POLYMERS, Issue 10 2009Cristina Canal Abstract The aim of this study was to evaluate the morphological characteristics and wetting properties of polystyrene-divinylbenzene (PS-DVB) solid foams and their modification through post-discharge plasmas. The low-density solid foams are mainly macroporous, but show a small fraction of mesopores; their characterization revealed differences in topography between the smoother surface and the rougher bulk, while from the chemical point of view both regions of the PS-DVB solid foams are hydrophobic. The macroporous structure of these materials with high pore volume makes them interesting for the design of new drug delivery systems, but some active principles and the physiological media are hydrophilic; therefore, it would be of interest to modify the wettability of the materials via post-discharge plasma treatments. [source] Chemische Produktion gemäß Koran und Thora.CHEMIE IN UNSERER ZEIT (CHIUZ), Issue 1 2008Chemie und Religion Die Herstellung von Produkten im Einklang mit den Gesetzen des islamischen oder jüdischen Glaubens stellt sowohl für die chemische Industrie als auch für die religiösen Autoritäten eine erhebliche Herausforderung dar, die nur in vertrauensvoller Zusammenarbeit gemeistert werden kann. Ein koscher- oder halal-Zertifikat bedeutet nicht, dass das Produkt aus chemischer Sicht besonders rein ist. Vielmehr wird garantiert, dass alle Rohstoffe koscher oder halal waren und der gesamte Verarbeitungsprozess im Einklang mit den religiösen Gesetzen erfolgt ist. Für die chemische Industrie öffnen sich neue Märkte und der gläubige Verbraucher kann sicher sein, dass eine zweite vertrauenswürdige Autorität den gesamten Herstellungsprozess überwacht hat. Industrial chemical production in agreement with the laws of Islamic or Jewish religion puts a considerable challenge on both, the companies and the religious authorities. The difficult problems can only be solved through trustworthy cooperation. A kosher or halal certificate doesn't mean that the product is especially pure from a chemical point of view. Rather it guarantees that all raw materials were kosher or halal and that non-kosher or haram material were not present during the entire production process. In a win-win-situation new markets will be opened for the chemical industry and the faithful followers are assured that a second trustworthy authority has overseen the entire manufacturing process. [source] Microwave-Assisted Kolbe-Schmitt Synthesis Using Ionic Liquids or Dimcarb as Reactive SolventsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 11 2009A. Stark Abstract The activation of relatively inert carbon dioxide as a building block for organic products is of interest from both ecological and chemical points of view. One of the few industrially relevant processes using CO2 is the Kolbe-Schmitt synthesis. Two strategies to obtain the carboxylated product 2,4-dihydroxybenzoic acid from resorcinol are presented: both Dimcarb and hydrogencarbonate- or methylcarbonate-based ionic liquids are employed as reactive solvents in a microwave-assisted reaction. Reaction optimization shows that the ionic liquids are more reactive than Dimcarb. However, Dimcarb offers advantages with regard to ecological aspects, such as the Global Warming and Human Toxicity Potential and the Cumulative Energy Demand, which were assessed as part of the process development. [source] | ||||||||||