Condensation of 4-aryl-4-oxobutanoic acids with benzylamines: Synthetic and structural studies on 1-arylmethyl-3-[(<Emphasis Type="Italic">E</Emphasis>)-1-arylmethylidene]-5-phenyl-2,3-dihydro-1H-2-pyrrolones

The microwave-mediated reaction of 4-aryl-4-oxobutanoic acids with benzylamines furnished 1-arylmethyl-3-[(E)-1-arylmethylidene]-5-phenyl-2,3-dihydro-1H-pyrrolones. This result is in contract to the earlier report on this reaction conducted under neat conditions. Structures for the products were assigned on the basis of spectral data and confirmed by independent synthesis. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 368–373, March, 2007.     

Determination of three analgesics in pharmaceutical and urine sample on nano poly (3, 4-ethylenedioxythiophene) modified electrode

Three analgesics, acetaminophen, acetylsalicylic acid, and dipyrone were determined by stripping voltammetry using nanosized poly(3,4-ethylenedioxythiophene)-modified glassy carbon electrode . The cyclic voltammetric behavior of the three analgesics was studied in aqueous acid, neutral, and alkaline conditions. One well-defined oxidation peak each for acetaminophen and acetylsalicylic acid and three oxidation peaks for dipyrone were observed in the cyclic voltammograms. The influence of pH, scan rate, and concentration revealed irreversible diffusion controlled reaction. A systematic study of the experimental parameters that affect the differential pulse stripping voltammetric response was carried out. Calibration was made under maximum peak current conditions. The scanning electron microscope analysis confirmed good accumulation of the drugs on the electrode surface. The range of study for both acetaminophen, acetylsalicylic acid were 0.015–0.4 and dipyrone was 0.025–0.4 μg/ml. The lower limit of determination for both acetaminophen, acetylsalicylic acid was 0.01 μg/mL and for dipyrone was 0.02 μg/mL. The suitability of the method for the determination of the three analgesics in pharmaceutical preparations and urine samples was also ascertained.     

Surface modification of LiMn2O4 thin films at elevated temperature

In order to improve the cycle stability of spinel LiMn₂O₄ electrode at elevated temperature, the LiCoO₂-coated and Co-doped LiMn₂O₄ film were prepared by an electrostatic spray deposition (ESD) technique. LiCoO₂-coated LiMn₂O₄ film shows excellent cycling stability at 55 °C compared to pristine and Co-doped LiMn₂O₄ films. The samples were studied by X-ray diffraction, scanning electron microscopy, Auger electron spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The excellent performance of LiCoO₂-coated LiMn₂O₄ film can be explained by suppression of Mn dissolution. On the other hand, the LiCoO₂-layer on the LiMn₂O₄ surface allows a homogenous Li⁺ insertion/extraction during electrochemical cycles and improves its structure stability.     

An on-line TDC-312 computer-controlled neutron diffractometer

The design and fabrication of an indigenous on-line computer controlled four-circle neutron diffractometer at the CIRUS reactor in Trombay are described. The diffractometer has an 18 in dia full-circle crystal-orienter which is sturdy enough to carry a cryostat. Three crystal orientation angles χ, φ and ω and the detector angle 2θ can be set to an accuracy of 0·01°. The four angle shafts are driven through precision worm-gears by SCR-controlled DC motors and their instantaneous positions sensed by optical digitizers. The diffractometer is interfaced to an ECIL TDC-312 computer system consisting of the CPU with 4K-memory, ASR-35 teletype, X-Y plotter and the digital input/output system (DIOS). The DIOS which operates under program control is a real-time peripheral device used to exchange information in digital form between the computer and the diffractometer. A software package consisting of over 40 useroriented teletype commands has been developed for on-line control and automatic data-acquisition.     

Influence of Co(III) Polypyridyl Complexes on Luminescence Behavior,DNA Binding,Photocleavage, Antimicrobial Activity and Molecular Docking Studies

A new ligand FIPB?=?5-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)furan-2-yl-2-boronic acid, having three cobalt(III) polypyridyl complexes [Co(phen)₂(FIPB)]³⁺(1) {FIPB?=?5-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)furan-2-yl-2-boronic acid}, (phen?=?1,10-Phenanthroline), [Co(bpy)₂(FIPB)]³⁺(2) (bpy?=?2,2’bipyridyl), [Co(dmb)₂(FIPB)]³⁺(3) (dmb?=?4, 4′-dimethyl 2, 2′-bipyridine) have been synthesized and characterized by elemental analysis, ES-MS,¹H-NMR, ¹³C-NMR, UV-Vis and FTIR. Their DNA binding behavior has been explored by various spectroscopic titrations and viscosity measurements, which indicated that all the complexes bind to calf thymus DNA by means of intercalation with different binding strengths. The binding properties of these all three complexes towards calf-thymus DNA (CT-DNA) have been investigated by UV-visible, emission spectroscopy and viscosity measurements.The experimental results suggested that three Co(III) complexes can intercalate into DNA base pairs,but with different binding affinities. Photo induced DNA cleavage studies have been performed and results indicate that three complexes efficiently cleave the pBR322-DNA in different forms. The three synthesized compounds were tested for antimicrobial activity by using Staphylococcus aureus and Bacillus subtilis organisms, these results indicated that complex 1 was more activity compared to other two complexes against both tested microbial strains. The in vitro cytotoxicity of these complexes was evaluatedby MTT assay, and complex 1 shows higher cytotoxicity than complex 2 and 3 on HeLa cells.

     

Viscosities and densities of tetraalkylammonium bromides in dimethylformamide-water mixtures at 25 and 35°C

Viscosity and desity data for KCl, KBr, Me₄NBr, Et₄NBr, Pr₄NBr, and Bu₄NBr from 0.005 to 3M in aqueous dimethylformamide solutions at 25°C and 35°C are presented. The data for dilute solutions were analyzed by means of the Jones-Dole equation and the ionic B coefficients evaluated. The data for concentrated solutions were analyzed by the Breslau and Miller equation and the effective flow volume, V₃ of the electrolytes obtained as a function of concentration. The limiting effective flow volume, V _e ^o was obtained from the Vand equation in the form used by Eagland and Pilling and it is shown that B=2.5 V _e ^o . With increasing DMF concentration V _e ^o increases for Me₄NBr but decreases for Pr₄NBr and Bu₄NBr. The same effect was observed by increasing temperature. This behavior is explained in terms of the structuring effect of the constituent ions and the effect of DMF on the overall structure of the binary solvent.     

Study of Anti-Apoptotic mechanism of Ruthenium (II)Polypyridyl Complexes via RT-PCR and DNA binding

A set of novel mononuclear polypyridyl complexes of Ru (II) with N – N donar ligands 1, 10 phenanthroline (phen), 2, 2′ bipyridine (bpy), 4, 4′-dimethyl 2, 2′ bipyridine (dmb) and an intercalating ligand (bnpip = 2-(4-butoxy-3-nitrophenyl)-1H-imidazo [4,5-f] [1,10] phenanthroline) have been synthesized and characterized by various spectral methods. The RT - PCR assays suggest that ruthenium (II) complexes inhibit MCF-7, breast cancer cell line by inducing apoptosis via inhibition of cell cycle check points cyclin D, cyclin E and also upregulation of caspase 8 (protein involved in late Apoptosis). Further the binding potency of Ru (II) complexes were investigated using various spectroscopic techniques like UV–visible, fluorescence and viscosity studies. The complex binds to DNA in an intercalative mode as confirmed by viscosity data with differential binding strength. All complexes show cleavage of the pBR322 DNA through a singlet oxygen production. Theoretical evidence via docking of the complex with DNA reveals the significant residues of binding as guanine.     

Synthesis and antioxidant properties of novel α-tocopherol glycoconjugates

Glycoconjugates of α-tocopherol (1), synthesized using click chemistry between α-tocopherol-azide and glyco-alkynes are solids, have enhanced water solubility and exhibit radical-scavenging activities comparable to 1, as determined by DPPH and lipid peroxidation assay methods.     

Characterization of poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) electrolytes complexed with different lithium salts

Poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) gel electrolytes comprising a combination of plasticizers, ethylene carbonate (EC) and propylene carbonate (PC) and lithium salt LiX have been prepared using the solution casting technique in an argon atmosphere. The prepared electrolytes were subjected to ionic conductivity, compatibility with lithium metal anode and thermogravimetric (TG)/differential thermal analysis (DTA). The membranes, which possess lithium salt, LiBF₄ exhibited maximum conductivity and on contrary it undergoes severe passivation with lithium metal. All these membranes are found to be stable thermally about 70 °C.