Novel catalytic membranes for selective reactions

A survey is given of the potentials of a new kind of catalytic membranes consisting of a catalyst that is immobilised in a dense polymer matrix. When homogeneous, catalytically active complexes are occluded, these membranes constitute a new way of heterogenation. In the case of solid state catalysts, these composite membranes can improve the activity of the catalyst by changing sorption or by allowing experimental set-ups in which solvents become redundant. This revised version was published online in June 2006 with corrections to the Cover Date.     

An In Situ FTIR Study of DBD Plasma Parameters for Accelerated Germination of Arabidopsis thaliana Seeds

Current agricultural practices are not sustainable; however, the non-thermal plasma treatment of seeds may be an eco-friendly alternative to alter macroscopic plant growth parameters. Despite numerous successful results of plasma-seed treatments reported in the literature, the plasma-treatment parameters required to improve plant growth remain elusive due to the plethora of physical, chemical, and biological variables. In this study, we investigate the optimal conditions in our surface dielectric barrier discharge (SDBD) setup, using a parametric study, and attempt to understand relevant species in the plasma treatment using in situ Fourier transform infrared (FTIR) absorption spectroscopy. Our results suggest that treatment time and voltage are key parameters for accelerated germination; however, no clear conclusion on causative agents can be drawn.     

Tepotinib Inhibits Several Drug Efflux Transporters and Biotransformation Enzymes: The Role in Drug-Drug Interactions and Targeting Cytostatic Resistance In Vitro and Ex Vivo

Tepotinib is a novel tyrosine kinase inhibitor recently approved for the treatment of non-small cell lung cancer (NSCLC). In this study, we evaluated the tepotinib’s potential to perpetrate pharmacokinetic drug interactions and modulate multidrug resistance (MDR). Accumulation studies showed that tepotinib potently inhibits ABCB1 and ABCG2 efflux transporters, which was confirmed by molecular docking. In addition, tepotinib inhibited several recombinant cytochrome P450 (CYP) isoforms with varying potency. In subsequent drug combination experiments, tepotinib synergistically reversed daunorubicin and mitoxantrone resistance in cells with ABCB1 and ABCG2 overexpression, respectively. Remarkably, MDR-modulatory properties were confirmed in ex vivo explants derived from NSCLC patients. Furthermore, we demonstrated that anticancer effect of tepotinib is not influenced by the presence of ABC transporters associated with MDR, although monolayer transport assays designated it as ABCB1 substrate. Finally, tested drug was observed to have negligible effect on the expression of clinically relevant drug efflux transporters and CYP enzymes. In conclusion, our findings provide complex overview on the tepotinib’s drug interaction profile and suggest a promising novel therapeutic strategy for future clinical investigations.     

Orthoamide. LI. Push-Pull-Butadiene und Heterocyclen aus CH2-aciden Verbindungen und Orthoamiden von Alkincarbonsäuren

Orthoamides. LI. Push-Pull-Butadienes and Heterocycles from Alkyne Carboxylic Acid Orthoamides and CH₂-acidic Compounds The acetylides 4b, 4f react with N,N,N′,N′,N″,N″-hexamethylguanidiniumchloride ( 5 ) to give the orthoamides 6b, 6f , resp. From CH₂-acidic compounds and the orthoamides 6a, c, e can be obtained the push-pull-substituted butadienes 8a–8aj . The 2,3,5-trimethyl-thiadiazolium salt 9 does not condense with 6e , as other CH₂-acidic compounds do, instead the vinylogous guanidinium salt 10a is produced. On heating, the ketenaminals 8d, aa cyclize to give the pyridone-carbonitriles 11a, b , resp. From 4-amino-coumarins 12 and the orthocarboxylic acid amideacetals 13a, b and the ketenaminal 16 resp., the amidines 14a–c and the heterocyclic compounds 15a–c resp., are formed. The enamines 17a–c, 19a, b react with the orthoamides 6a–f to give the pyridine derivatives 18a–1, 20a–h and 21a, b , resp. Analogously, from 6-aminouracil 22 and 6a, b, e, f are formed the pure 7-dimethylaminopyrido[2,3-d] pyrimidines 23a, b or mixtures of compounds 23c, d and the isomeric 4-dimethylamino-pyrido[2,3-d]pyrimidines 24a, b resp., which can be separated via their salts 25a,b/26a,b . The heterocyclic compounds 30a–d, 32a,b can be prepared from the pyrazole derivatives 28, 31 resp. and the orthoamides 6a–f .     

Fluorescent polyacrylonitrile with 1,8-naphthalimide side chains

The copolymerization of acrylonitrile with two polymerizable fluorescent naphthalimide dyes has been investigated. It was found that the monomeric dyes took part in the polymerization and 94–96% of initially 1 wt.-% (relative to acrylonitrile) were covalently bound in the polymer chain, and thus new fluorescent side-group copolymers were obtained. The absorption and basic photophysical characteristics of monomeric naphthalimid dyes and copolymers in dimethylformamide are reported.     

Solubility of potassium ferrate in 12 M alkaline solutions between 20°C and 60°C

The solubility of potassium ferrate (K₂FeO₄) was measured in aqueous solutions of NaOH and KOH of total concentration 12 M containing various molar ratios of KOH:NaOH in the range 12:0 to 3:9. Several analytical methods were tested for the determination of ferrate concentration. The final method chosen consisted of potentiometric titration of the ferrate sample with an alkaline solution of As₂O₃. The assumption was made that ferrate dissociates in concentrated KOH solutions predominantly to KFeO₄⁻. The solubility constant, S, defined as the product of the molar concentration of the potassium ion, K⁺, and the ferrate anion, KFeO₄⁻, was found to be 0·044 ± 0·006 mol² dm⁻⁶ for 20°C, 0·093 ± 0·004 mol² dm⁻⁶ for 40°C and 0·15 ± 0·09 mol² dm⁻⁶ for 60°C. From these results the heat of dissolution of K₂FeO₄ was calculated as −14·3 kJ mol⁻¹. At 60°C the enhanced decomposition of the ferrate at the higher temperature led to a greater deviation in solubility values compared with data for either 20°C or 40°C.