the formation constants (log k), of the complexes formed between a number of amino acids(glycine , l-valine and l-alanine) with p-sulfonatocalix [4] arene at varying temperatures (25± 0.1to 65 ± 0.1 °c) in aqueous solutions and at natural ph of p-sulphonato-calix [4] arene (ph=3.2) bymeans of uv-vis spectrophotometeric technique have been investigated. at this ph the guestmolecule is in its cat...

A spectrophotometric study concerning the interaction between Trimethoprim (TMP) ,Sulfamethoxazole (SFMx), as n-donor and 2,3-dichloro-5,6- dicyano-P-benzoquinine (DDQ) and chloranilic acid (CA) as π-acceptor were been performed at 25°C. The results of interaction of CA and DDQwith TMP indicate the formation of a 1:1, 1:2, charge transfer complexes through non equilibrium reactions. In the case...

Recently we have reported a 13C n.m.r. investigation on the site of protonation in the diazanaphthalenes.' This group of N-heterocycles consists of ten compounds: cinnoline (1,2-diazanaphthalene, l), quinazoline (1,3-diazanaphthalene, 2), quinoxaline (1,4-diazanaphthalene, 3), 1 ,5-naphthyridine (1,5diazanaphthalene,4), 1,6-naphthyridine (1,6-diazanaphthalene, 3, 1,7-naphthyridine (1,7-diazanap...

Bu çalışmada, trisiklik antidepresanlara alternatif olarak kullanılan selektif serotonin geri alım inhibitörleri (SSRİ)’nden sitalopram, fluvoksamin ve sertralinin su-asetonitril ikili karışımında, ters faz sıvı kromatografik (RPLC) yöntemle alıkonma davranışı incelenmiştir. Kromatografik analizler, mobil pH’sı 6,5 ila 10,5 arasında değişen, %45-%55 (h/h) asetonitril içeren asetonitril-su karış...

When protons are exchanging for bivalent cations (Cu(2+), Zn(2+), or Ca(2+)) on the carboxylic groups of Nitella flexilis cell wall, the values of the respective global equilibrium constants do not change up to a protonation degree of 80%. These values drastically increase at higher proton concentrations and tend to approximately 3.4, which is the intrinsic pK value of the constitutive alpha-d-...

The interaction between benzo-15-crown-5 (B15C5), dibenzo-18-crown-6 (DB18C6), dibenzyl-daza-18crown-6 (DBzDA18C6), N-phenyl-aza-15-crown-5 (NPhA15C5) and dibenzopyridine-18-crown-6 (DBPy18C6) with π-acceptor 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in chloroform solution was studied spectrophotometrically. The interaction of B15C5-DDQ and DB18C6-DDQ caused the formation...

3-Hydroxy-1,2-dimethylpyridin-4(1H)-one (deferiprone) is a successful iron chelator, which has been widely investigated for its activity in mitigating iron overload and in protecting against oxidative stress due to Reactive Oxygen Species (ROS). Herein, we present the synthesis, characterisation, physicochemical properties and antioxidant activity of two novel bioconjugates of β-cyclodextrin be...

The present study investigates the binding properties of four dansyl substituted aza-crown ethers with alkali, alkaline earth metal ions and ammonium. The influence of the solvent polarity and protonation on the photophysical properties of the compounds was studied by UV/Vis and fluorescence methods. The host species caused only slight changes on the absorption spectra of the ligands. The fluor...