Ion pairs (also known as salt bridges) of electrostatically interacting cationic and anionic moieties are important for proteins and nucleic acids to perform their function. Although numerous three-dimensional structures show ion pairs at functionally important sites of biological macromolecules and their complexes, the physicochemical properties of the ion pairs are not well understood. Crysta...

we have prepared and characterized a few mn (iii) complexes by using a few bidentate and tridentate ligands. spectra of the manganese (abstract we have prepared and characterized a few mn (iii) complexes by using a few bidentate and tridentate ligands. spectra of the manganese (iii) ion in a variety of molecular environments are reported . on the basis of solution spectra, some of these complex...

the complexation reactions between methylthymol blue (mtb) and co2+, ni2+, cu2+, zn2+ and pb2+ ions have been studied in different water-methanol mixtures at ph 4.45 and 25 °c by a spectrophotometric technique. the stepwise stability constants of the resulting 1:1 and 2:1 (metal ion to ligand) complexes were determined from the absorbance-mole ratio data. it was found that the overall stability...

A conductance study of the interaction between Cs+, Rb+, NH4+, K+, T1+ and Ag+ ions and18-crown-6 (18C6), benzo-18-crown-6 (B18C6), dicyclohexyl-18-crown-6 (DC18C6),dicyclohexyl-24-crown-8 (DC24C8), dibenzo-24-crown-8 (DB24C8) in different binarymixtures of acetonitrile (AN) with dimethylsulfoxide (DMSO) and dimethylformamide (DMF)at 25 °C has been carried out. Formation constants of the result...

Simple, precise, selective, and expeditious spectrophotometric methods have been developed for the determination of itopride (ITO), midodrine (MID), diclofenac (DIC), mesalamine (MES), and sumatriptan (SUM) in their pure form as well as in pharmaceutical preparations. The method was based on ion-pair complex formation between the drugs and anionic dye, bromothymol blue in an acidic medium (pH 2...

Obtaining quantities of highly pure duplex DNA is a bottleneck in the biophysical analysis of protein-DNA complexes. In traditional DNA purification methods, the individual cognate DNA strands are purified separately before annealing to form DNA duplexes. This approach works well for palindromic sequences, in which top and bottom strands are identical and duplex formation is typically complete....

INTRODUCTION Nimesulide is a relatively cyclo-oxygenase-2 (COX2) selective, non-steroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic properties. Its approved indications are the treatment of acute pain, the symptomatic treatment of osteoarthritis and primary dysmenorrhoea in adolescents and adults above 12 years old to decrease the risk of hepatotoxicity. It may be used orall...

in this study, a sensitive method of dispersive liquid phase microextraction based on ion-pair combined with the flame atomic absorption spectrometry was proposed for the determination of trace ni(ii) using aliquat 336-chloride as ion pair agent. several factors which have effect on  the microextraction efficiency of ni(ii), such as ph, extraction and dispersive solvent type and their volume, c...