In Situ Immobilization on the Silica Gel Surface and Adsorption Capacity of Poly[N-(4-carboxyphenyl)methacrylamide] on Toxic Metal Ions

In situ immobilization of poly[N-(4-carboxyphenyl)methacrylamide] has been performed on silica gel surface. Infrared (IR) and mass spectroscopies as well as thermogravimetry (TG) analysis have been used to elucidate the structure of immobilized polymer. An adsorption capacity of the synthesized composite towards Cu(II), Pb(II), Mn(II), Fe(III), Co(II), and Ni(II) ions has been estimated. Adsorption activity to microquantities of Pb(II), Cu(II), and Ni(II) in a neutral aqueous medium has been observed

Molecular Actuators in Action: Electron-Transfer-Induced Conformation Transformation in Cofacially Arrayed Polyfluorenes

There is much current interest in the design of molecular actuators, which undergo reversible, controlled motion in response to an external stimulus (light, heat, oxidation, etc.). Here we describe the design and synthesis of a series of cofacially arrayed polyfluorenes (MeFnHm) with varied end-capping groups, which undergo redox-controlled electromechanical actuation. Such cofacially arrayed polyfluorenes are a model molecular scaffold to investigate fundamental processes of charge and energy transfer across a π-stacked assembly, and we show with the aid of NMR and optical spectroscopies, X-ray crystallography and DFT calculations that in the neutral state the conformation of MeFnH1 and MeFnH2 is open rather than cofacial, with a conformational dependence that is highly influenced by the local environment. Upon (electro)chemical oxidation, these systems undergo a reversible transformation into a closed fully π-stacked conformation, driven by charge-resonance stabilization of the cationic charge. These findings are expected to aid the design of novel wire-like cofacially arrayed systems capable of undergo redox-controlled actuation

Purification and characterization of Fe-containing superoxide dismutase from Methanobrevibacter arboriphilus strain AZ

Superoxide dismutase (SOD) was purified from cells of the strict anaerobic methanogenic archaeon Methanobrevibacter arboriphilus strain AZ. The four-step purification procedure resulted in enzyme with specific activity of 3970 units/mg and yield of 22%. It was shown that the SOD is a Fe-containing homotetramer composed of subunits of 21.2 kD each. Sodium azide (13.5 mM), unlike KCN, inhibits the activity of the SOD. Hydrogen peroxide (0.5 mM) inactivates the enzyme, which is consistent with the properties of the known Fe-containing SODs from methanogenic Archae

Divalent metal complexes of 4-amino-N-pyrimidin-2-ylbenzene sulphonamide and their antimalarial activities against Plasmodium berghei

Coordination compounds of 4-amino-N-pyrimidin-2-ylbenzene sulphonamide (APS) were synthesized. The complexes were formulated as [Co(APS)2(H2O)2], [Cu(APS)2(H2O)2], [Ni(APS)2(H2O)2], [Cd(APS)2](H2O)2, [Fe(APS)3](H­2O)­3 and [Mn(APS)2(H2O)2] characterized by elemental analysis, conductivity, IR, UV-Vis, magnet moment and 1H-NMR and mass spectroscopies. In all the complexes the metal ions coordinate through pyrimidinic nitrogen and sulphonamidic nitrogen of the two molecules of APS. The suggested structure for Cd(II) complex of APS is tetrahedral, while that of Cu(II), Mn(II) and Ni(II) APS complexes is octahedral. The inner coordination spheres were occupied by two water molecules in Co(II), Mn(II), Cu(II), Ni(II) APS complexes except Cd(II) with 2 molecules of  water outside the coordination  sphere. Fe(III) coordinates with 3 molecules of APS with 3 molecules of water outside the coordination sphere. The antiparasitic studies using Plasmodium berghei as test organism showed that the Fe(III) complex exhibits higher activity than chloroquine and  ligand. All other complexes have lower antiparasitic activity.KEY WORDS: Sulphonamide, Antimalarial activity, Plasmodium berghei Bull. Chem. Soc. Ethiop. 2011, 25(3), 371-380

Ornithogalum Umbellatum L. Bitkisindeki Flavonoidler

DergiPark: 245875trakyafbdBu çalışmada, Edirne civarında yetişen Ornithogalum umbellatum L.bitkisinin içerdiği flavonoid bileşikleri incelenmiştir. Bitkinin etanolik ekstraktı kromatografık teknikler yardımı ile ayrılmış ve saflaştırılmıştır. İzole edilen bileşiklerin kimyasal yapıları UV, IR, NMR ve EI kütle spektroskopileri kullanılarak aydınlatılmıştır. Isovitexin (1), Saponarin (2), Isoorientin (3) olmak üzere üç C-glikozil flavonoid Ornithogalum umbellatum L.bitkisinin toprak üstü kısımlarında tespit edilmiştir.In this study, the flavonoids in Ornithogalum umbellatum L. grows around Edirne have been investigated. Ethanolic extracts of the plant were seperated and purificated by chromatographic techniques. The chemical structures of the isolated compounds were elucidated by UV, IR, NMR and EI and FAB mass spectroscopies. Three C-glycosylflavones were identified in the aerial parts of Ornithogalum umbellatum L.; Isovitexin (1), Saponarin (2), Isoorientin (3)

Design and synthesis of New Methyl4-Hydroxy-1-Alkyl-2-aryl 5-Oxo 2,5-Dihydropyrrole-3-Carboxylate Derivatives as Selective COX-2 Inhibitors

The non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly medications in the world. The mechanism of action of these drugs is the inhibition of cyclooxygenase (COX) enzyme, which catalyzes the first step of the biosynthesis of PGG2 from arachidonic acid. COX isozymes exist at least in two isoforms, COX-1 and COX-2.The constitutive COX-1 isozyme is found in plateletes, kidneys, and the gastrointestinal tract and is believed to be responsible for the maintenance of physiological functions such as gastro protection and vascular homeostasis. In contrast, the COX-2 enzyme is the inducible isoform that is produced by various cell types upon exposure to cytokines, mitogens, and endotoxins released during injury and therefore molecules that inhibit its enzymatic activity would be of therapeutic value. The gastrointestinal side effects associated with NSAIDs are due to the inhibition of gastroprotective PGs synthesized through the COX-1 pathway. Thus, selective inhibition of COX-2 over COX-1 is useful for the treatment of inflammation and inflammation-associated disorders with reduced gastrointestinal toxicities when compared with NSAIDs. The recent market withdrawal of some coxibs such as rofecoxib and valdecoxib due to their adverse cardiovascular side effects clearly delineates the need to develop alternative structures with COX-2 inhibitory activity. For this reason novel scaffolds with high selectivity for COX-2 inhibition need to be found and evaluated for their anti-inflammatory effects. As a result, in this study, new methyl4-hydroxy-1-alkyl-2-aryl 5-oxo 2,5-dihydropyrrole-3-carboxylate derivatives were designed and sythesized based on the structure-activity relationship of selective COX-2 inhibitors. A mixture of 4-methylthiobenzaldehyde, arylamine derivatives and para-toluene sulfonic acid (PTSA) as a catalyst in ethanol was stirred at room temperature for 1 hour until a white precipitate appeared. Then, dimethylacetylenedicarboxylate (DMAD) was added. The reaction was stirred at room temperature until a new precipitate appeared. Finally, the resulting precipitate was recrystallized with ethanol. In the next step, a solution of Oxone in water was added to a well-stirred solution of the resulting product and diethyamine as a catalyst in acetonitrile. After the completion of the reaction, the precipitates were filtered and recrystallized with ethanol. All the target compounds were synthesized in good to high yields and the chemical structures were confirmed by IR, 1HNMR and Mass spectra. A novel series of methyl4-hydroxy-1-alkyl-2-aryl 5-oxo 2,5-dihydropyrrole-3-carboxylate derivatives was designed and synthesized as selective COX-2 inhibitors in good yields. The target compounds were characterized via IR, 1HNMR and Mass spectroscopies. The COX-2 inhibitory activity of the target compouds is under investigation

GARDINERIN, A BIOLOGICALLY ACTIVE ACETOGENIN FROM THE SRI LANKAN GONIOTHALAMUS GARDINERI HOOK. F. AND THOMSON

Objective: The study was undertaken to isolate biologically active compounds from Goniothalamus gardineri, a plant endemic to Sri Lanka. Methods: Roots and flowers of Goniothalamus gardineri were extracted into dichloromethane and methanol. A new acetogenin, gardinerin isolated by column chromatography of the dichloromethane extract was structurally characterized using NMR and Mass spectroscopies. It was found to be mosquito larvicidal (against 2nd instar larvae of Aedes aegypti), cytotoxic (in the brine shrimp assay) and antioxidant (DPPH assay). Results: Gardinerin exhibited potent mosquitolarvicidal activity (LC50 = 0.0744±0.37 ppm.), cytotoxicity (LC50 = 1.5±0.37 ppm) and antioxidant activity (IC50 =10.02±0.01 ppm). The same extract furnished (5R)-goniothalamin. The hexane extract of the flowers of G. gardineri yielded poriferesterol and stigmast-4, 22-dien-3-one.Conclusion: The endemic plant G. gardineri has yielded an acetogenin possessing highly potent antioxidant, cytotoxic and mosquitolarvicidal activity. Â

Synthesis and Characterization of a New Triptycene-Based Tripod

The 18th International Electronic Conference on Synthetic Organic Chemistry session General Organic SynthesisHerein, we report an efficient and facile synthesis of a new triptycene based tripodal ligand containing both imine functionality and phenolic pendant arms. This tripodal unit is a potential building block for constructing novel supramolecular architectures. The newly synthesized 2,6,14-triaminotriptycene derivative, which was characterized by FT-IR, UV−Vis absorption, mass and NMR spectroscopic techniques has interesting properties such as high solubility in common organic solvents and fluorescence emission in THF solution (λ = 550 nm

Functionalization of solid surfaces by pulsed plasma polymerization

Pulsed plasma polymerization provides a direct method for the functionalization of solid surfaces. Compared to low power continuous wave plasma conditions, it provokes very little monomer fragmentation and leads to high levels of structural retention. The monomers investigated in this thesis contained a polymerizable double bond and either a perfluoro, epoxide, cyano, hydroxyl or furan functionality. Under pulsed conditions activation of the double bond occurs during the time on period and conventional intermolecular propagation reactions occur during the time off. In the case of dienes, cyclic structures are formed, via intramolecular propagation. The plasma polymers were investigated using X-ray photoelectron, infrared, ultraviolet/visible and secondary ion mass spectroscopies, nuclear magnetic resonance, contact angle and gel permeation chromatography. Epoxide and hydroxyl functionalized solid surfaces could be further functionalized via conventional chemistry reactions. Furan functionalized solid surfaces were capable of undergoing Diels-Alder reactions. The cyano functionalized layers were found to readily complex silver ions from solution. Epoxide and cyano functionalized surfaces exhibited adhesive behavior