ABSTRACT
Formation of metal ligand complex species of 5-sulphosalicylic acid with CaII, MgII and ZnII metal ions have been studied potentiometrically in various composition (0.0, 0.5, 1.0. 1.5, 2.0, and 2.5% w/v) of cetyltrimethylammonium bromide (CTAB). The study has been carried out at 303 K temperature and maintaining 0.16 mol dm-3 ionic strength using NaCl. The dynamic species belongs to 5-sulphosalicylic acid are LH2 - and LH2-. The best fit of complex speciation has been preferred on basis of statistical parameters like skewness, χ 2, Kurtosis and crystallographic R-factor. ML2H, ML2H2 and ML3H3 type complex were formed by the complexation of 5-sulphosalicylic acid with the metal ions. The change in stability of complex species with composition of the surfactant has been illustrated on the basis electrostatic grounds. Distribution of chemical species with respect to pH and various compositions medium and probable complex equilibria are also studied.
ABSTRACT
The interaction of DNA with six water soluble benzo[a]phenoxazinium chlorides mono- or di-substituted with 3-chloropropyl groups at the O and N of 2- and 9-positions, along with methyl, hydroxyl and amine terminal groups at 5-positions, was investigated by photophysical techniques. The results indicated that almost all compounds intercalated in DNA base pairs at phosphate to dye ratio higher than 5. At lower values of this ratio, electrostatic binding mode with DNA was observed. Groove binding was detected mainly for the benzo[a]phenoxazinium dye with NH2·HBr terminal. The set of six benzo[a]phenoxazinium chlorides proved successful to label the migrating DNA in agarose gel electrophoresis assays. These finding proves the ability of these benzo[a]phenoxazinium dyes to strongly interact with DNA.
Subject(s)
DNA/chemistry , Fluorescent Dyes/chemistry , Halogenation , Intercalating Agents/chemistry , Oxazines/chemistry , Animals , Anisotropy , Electrophoresis, Agar Gel , Iodides/chemistry , Ions , Salmon , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , TemperatureABSTRACT
Ultrasound irradiation was used for the first time towards the synthesis of new Nile Blue related benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic system. The efficacy of sonochemistry was investigated with some of our earlier reported synthesis of benzo[a]phenoxazinium chlorides. This newer protocol proved competent in terms of reaction times and enhanced yields. Photophysical studies carried out in ethanol, water and simulated physiological conditions, revealed that emission maxima occurred in the range 644-656 nm, with high fluorescent quantum yields. Other attractive feature exhibited by these materials includes good thermal stability. These properties might be useful in the development of fluorescent probes for biotechnology.
Subject(s)
Fluorescent Dyes/chemistry , Fluorescent Dyes/chemical synthesis , Oxazines/chemistry , Oxazines/chemical synthesis , Ultrasonics , Ethanol/chemistry , Hydrogen-Ion Concentration , Organic Chemicals , Temperature , Water/chemistryABSTRACT
An efficient and practical method for the synthesis of indolyl-nitroalkane derivatives catalyzed by N-bromosuccinimide is described. The generality of this method was demonstrated by synthesizing an array of diverse 3-substituted indole derivatives by the reaction of different beta-nitrostyrenes with various substituted indoles. Simple reaction conditions accompanied by good yields of indolyl-nitroalkanes are the merits of this methodology.
Subject(s)
Alkanes/chemical synthesis , Bromosuccinimide/chemistry , Indole Alkaloids/chemical synthesis , Indoles/chemical synthesis , CatalysisABSTRACT
Spiroketals are widely found as substructures of many naturally occurring compounds from diverse sources including plants, animals as well as microbes. Naturally occurring spiroketals are biologically active and most of them are chiral molecules. This article aims at reviewing the asymmetric synthesis of biologically active spiroketals for last 10 years (1998-2007).
Subject(s)
Furans/chemical synthesis , Spiro Compounds/chemical synthesis , Biological Products/chemical synthesis , Optical Rotation , StereoisomerismABSTRACT
The reaction of aldehyde with allylsilane in acetonitrile mediated by boron trifluoride etherate generated 4-aminotetrahydropyrans in good yields. The product is highly stereoselective.
