The topic of charge-transfer (CT) complexation of vital drugs has attracted considerable attention in recent years owing to their significant physical and chemical properties. In this study, CT complexes derived from the reaction of the anti-hyperuricemic drug allopurinol (Allop) with organic p-acceptors [(picric acid (PA), dichlorodicyanobenzoquinone (DDQ) and chloranil (CHL)] were prepared, i...

Traditional systems for olefin/paraffin separation, like low-temperature distillation, are expensive and very energy consuming, and therefore, alternative separation methods are desired. Facilitated transport membranes are new tools for this separation to be substituted in large scale separation of olefin-paraffin mixtures. To design a membrane process for olefin-paraffin separation, equilibriu...

The complexation of Cm(III) with acetate is studied by time resolved laser fluorescence spectroscopy (TRLFS) as a function of ionic strength, ligand concentration, temperature and background electrolyte (NaClO4, NaCl and CaCl2 solution). The speciation of Cm(III) is determined by peak deconvolution of the emission spectra. To obtain the thermodynamic stability constants (log K) for the formatio...

Complexation and conformational studies of coenzyme NAD+ with aluminum were conducted in acidic aqueous solutions (pH 2-5) by means of potentiometry as well as multinuclear (1H, 13C, 31P, 27Al) and two-dimensional (1H, 1H-NOESY) NMR spectroscopy. These led to the following results: (1) Al could coordinate with NAD+ through the following binding sites: N7' of adenine and pyrophosphate free oxyge...

The characteristics of host-guest complexation between cyclodextrins (beta-CD, DM-beta-CD, HP-beta-CD) and protonated (pH 1.9, 6.2) or basic (pH 10.2) forms of trifluoperazine (TF) were investigated by spectrometric method. The association constants of complexes obtained at different temperatures and pH were calculated using Scott's equation and the thermodynamic parameters (deltaH, deltaS and ...

The complexation of oligonucleotides and antisense drugs with a cationic surfactant, cetylpyridinium chloride (CPC), has been studied using electrochemistry at a micrometer sized liquid/liquid interface. This method can be used to investigate the effect of chemical and structural modifications on the complexation behaviour of oligonucleotides. For the interaction between CPC and oligonucleotide...

The triple-proton-transfer reactions of 8H-1,8-naphthyridin-2-one (8H-naph) have been investigated by employing different ab initio quantum mechanical methods. The proton transfer reactions studied were facilitated through complexation of 8H-naph with a 1,3-propanediol molecule or two adjacent water molecules. Identical proton transfer reactions were studied using a model system of 8Hnaph to in...

The effect on picosecond reaction dynamics due to complexation of a reactive molecule with cyclodextrins was examined, with the trans-cis photoisomerization of stilbene as an example. In the presence of a-cyclodextrin, a single, slow exponential decay of trans-stilbene fluorescence is observed, consistent with the formation of a single complex. In contrast, in the presence of 8-cyclodextrin, th...

Pharmaceutical preparations usually contain preservatives and sweeteners. When parabens are used as preservatives and a polyol as a sweetener, a transesterification reaction may happen, yielding the transester polyol-paraben. The products formed in the transesterification reaction of methylparaben and sorbitol were analyzed by micellar electrokinetic chromatography and by HPLC. Up to six positi...

Ab initio quantum chemical calculations have been applied to the study of the molecular structure of phenol derivatives and oligomers produced during peroxidasecatalyzed oxidation. The interaction of substrates and oligomers with Arthromyces ramosus peroxidase was analyzed by docking methods. The most possible interaction site of oligomers is an active center of the peroxidase. The complexation...