Azino-Fused Benzimidazolium Salts as DNA Intercalating Agents. 2.

Abstract

The synthesis of new pyrido[1,2-a]- and pyridazino[1,6-a]benzimidazolium salts by basic condensation of 1,3-disubstituted 2-alkylbenzimidazolium salts and 1,2-diketones and subsequent chemical transformations is described. The DNA-binding properties were examined by UV-vis spectroscopy, viscosimetric determinations, and molecular modeling techniques. The presence of a flat polycyclic hydrocarbon moiety such as a naphthalene-1,8-diyl or a biphenyl-o,o'-diyl, fused to the cationic heterocycle, appears to enhance the interaction with DNA. Variation of the substituents on the indole-like N will allow us to build up a new series of bis-salts with bis-intercalating properties.

Temperature Effect on Binding Affinity and Stoichiometry Between Some Steroids and Human Serum Albumin

“…26 Some techniques such as gel electrophoresis, 42 X-ray crystallography, 43 NMR, 44 fluorescence, 45,46 differential scanning calorimetry (DSC), 47 infrared spectroscopy, 37,40 UV/Vis. spectroscopy, [46][47][48] circular dichroism (CD) spectroscopy 49 and electrochemistry, [50][51][52] have been intensively used to study the molecular interactions. In recent years, there has been a growing interest in the electrochemical and spectroscopic investigation of molecular interations.…”

“…51,52 Also, spectroscopic and voltammetric techniques have been testified to be of high sensitivity, relatively low cost, direct monitoring and simplicity. [46][47][48][49][53][54][55][56][57] Except for only the interaction of albumin and fusidic acid by zone microelectrophoresis in 0.05 M barbitone sodium buffer pH 8.4, 58 the voltammetric and spectroscopic studies on the interactions of three steroids which are presented in Scheme 1 ( fusidic acid (FA), ouabain (OUB) and ethynodioldiacetate (ETH), respectively) with HSA at the physiological pH could not be traced in the literature. Therefore, the main goal of present study is to investigate the interactions of these steroids with HSA at the physiological pH, using the amperometric method, UV-Vis and FT-IR spectroscopy techniques in aqueous solution.…”

Novel biologically active nitro and amino substituted benzimidazo[1,2-a]quinolines

“…2,3,4 The benzimidazole unit which has a structural similarity with purine, is also the key building block for a variety of derivatives that are known to play crucial roles in the functions of a number of biologically important molecules. Besides, benzimidazoles represent the major backbone of numerous of synthetic medical and biochemical agents possessing different chemical and pharmacological features which impart them diverse biological properties like anticancer, 5,6,7 antiviral, 8,9 antibacterial, 10,11 antifungal, 12 antihistaminic 13 and anticonvulsant activity. 14 As a part of our continuing search for potential anticancer agents related to benzimidazole derivatives, we have recently reported on the synthesis, cytostatic evaluation, DNA/RNA interaction study and proteomic profiling of a series of amidino-substituted heterocyclic benzimidazoles and benzimidazo [1,2-a]quinolines.…”

Synthesis and Cytotoxic Activity of pyridazino[1′,6′:1,2]pyrido[3,4-b]indol-5-inium derivatives as anti-cancer agents

“…Our interest in the field focussed our studies on DNA intercalators having a bridgehead quaternary nitrogen, and led us to prepare some benzimidazolium 9,10 and g-carbolinium 11À13 cations, which showed intercalating properties 10À13 and in vitro antiproliferative activity. 9 The very related pyridazino[1 0 ,6 0 :1,2]pyrido[3,4-b]indol-5-inium system has been also previously prepared in our laboratory by condensation of a b-carbolinium salt with 1,2-dicarbonyl 14 derivatives (Westphal reaction). The method was applied to the synthesis of the naturally occurring alkaloid flavocorylene and related zwitter- (2) or harmine (3), a series of compounds 4 (harmane series), 5 (harmol series) and 6 (harmine series) were prepared, with variations at the domains 1 (bromo, nitro, amino, alkoxy or hydroxy), 2 (carbamate, ester, amide, aliphatic saturated or unsaturated) and 3 (aliphatic saturated, unsaturated or aromatic) (Fig.…”