p-TSA-catalyzed one-pot synthesis and docking studies of some 5H-indeno[1,2-b]quinoline-9,11(6H,10H)-dione derivatives as anticonvulsant agents

The present work describes a facile, one-pot three component environment friendly, green synthesis of a series of 5-(4-methoxyphenyl)-7,7-dimethyl-10-phenyl-7,8-dihydro-5H-indeno[1,2-b]quinoline-9,11(6H,10H)-dione derivatives 8(a-n). 1,3-indanedione, aryl-aldehyde and enaminone was thoroughly ground in the presence of catalytic amount of p-toluene sulfonic acid (p-TSA) to give the titled compounds in good yields. All the synthesized derivatives were evaluated for their anticonvulsant activity using the maximal electroshock (MES) method with phenytoin as a standard drug along with their neurotoxicity effect. Derivatives 8b, 8e and 8k exhibited significant anticonvulsant activity (P<0.001). The neurotoxicity study clearly revealed that all the tested compounds are non-toxic at a dose of 40 mg/kg. The molecular modeling studies also predicted good binding interactions of most active molecules with the serotonin 5-HT_2A receptor. Therefore, it can be safely concluded that synthesized derivatives 8(a-n) would represent useful leads for further investigation in the development of a new class of anticonvulsant agents.     

Metabolic and biochemical changes caused by gamma irradiation in plants

Applications involving radioisotopes and radiations reveal a great promise particularly for the welfare of the society. However, in the event of a nuclear accident, the direct and indirect effect of radionuclide and radiation transfers in soil–plant–air environment are envisaged on almost all the components of the food chain. It also assumes significance as we often overlook the fact that radiations, emitted by any radioisotope although cannot be seen or felt, interacts with matter and could alter its biochemical, biophysical and biological characteristics. The interaction of ionizing radiation with human body and consequent biological effects are well characterized and quantified using data derived from the radiation workers and/or the nuclear accidents around the world. However, radiation impact on agriculture viz a viz economic productivity are not well understood and available data is scanty, scattered and inconclusive. At the plant level the effects could be visualized at morphological, biochemical, physiological and/or biophysical levels, where the magnitude of the effected change depends heavily on the exposure dose, soil, farm management and other environmental variables. This review attempts to collate and critically analyze the available researches on how the ionizing radiation might interact with crops at the whole plant or tissue or cell level to affect economic yield under various edaphic variables where not only the productivity but also the quality of the agri-produce may become vulnerable.     

Polymer-doped ferroelectric liquid crystal: UV absorbance,fluorescence and electro-optical study

In this study, UV absorption, fluorescence and electro-optical study have been performed for pure ferroelectric liquid crystal (FLC) and its three different concentrations, i.e. 1%, 3% and 5% of fluorescent polymer in the pure FLC. We observed that there is higher value of UV absorption for fluorescent polymer-doped system in comparison to the pure system. We have found excitation wavelength, emission wavelength and quantum yield for all the mixtures. Quantum yield shows the probability of excited state being deactivated by fluorescence rather than non-radiative mechanism. The higher value of spontaneous polarization and faster response has been observed for fluorescent polymer-doped system compared to the pure FLC system. The electro-optical study also suggests that there exists an optimum concentration of fluorescent polymer for which we have found highest spontaneous polarization and least response time.     

Development of a temperature-responsive agarose-based ion-exchange chromatographic resin

A temperature-responsive ion-exchange resin (ItBA) has been prepared by grafting poly(N-isopropylacrylamide-co-acrylic acid-co-tert-butylacrylamide; ItBA) onto cross-linked agarose. A carboxymethylated ion exchanger (CM) of similar charge density was also prepared. Maximum adsorption capacities (B_max) for lactoferrin at 20 °C and 50 °C were determined for both resins by batch adsorption procedures. Dynamic adsorption and desorption characteristics of the CM and ItBA with lactoferrin were established, as well as the ability of ItBA to selectively adsorb and desorb lactoferrin in the presence of other proteins. With the CM-agarose resin there was no significant difference between the B_max values obtained at 20 °C and 50 °C. However, for the agarose-based ItBA resin the B_max value at 50 °C was almost three times higher than the B_max value at 20 °C. Dynamically, lactoferrin adsorbed to the ItBA packed column at 50 °C with a significant proportion of the adsorbed lactoferrin desorbed by reducing the temperature to 20 °C. In addition, anionic proteins did not adsorb to the ItBA packed column, and did not interfere with the dynamic adsorption/desorption behaviour of lactoferrin. These results indicate that this new temperature-responsive agarose-based ItBA resin has potential for the fractionation of whey proteins, with good selectivity for cationic proteins.     

LC‐MS/MS determination and pharmacokinetic study of lacidipine in human plasma

A robust, specific and fully validated LC‐MS/MS method as per general practices of industry has been developed for estimation of lacidipine (LAC) with 100 μL of human plasma using lacidipine‐¹³C8 as an internal standard (IS). The API‐4000 LC‐MS/MS was operated under the multiple reaction‐monitoring mode. A simple liquid–liquid extraction process was used to extract LAC and IS from human plasma. The total run time was 3.0 min and the elution of LAC and IS occurred at 1.96 and 1.97 min; this was achieved with a mobile phase consisting of 5 mm ammonium acetate buffer–acetontrile (15:85 v/v) at a flow rate of 0.60 mL/min on a Zorbax SB C₁₈ (50 × 4.6 mm, 5 µm) column. A linear response function was established for the range of concentrations 50–15,000 pg/mL (r > 0.998) for LAC. The current developed method has negligible matrix effect and is free from unwanted adducts and clusters which are formed owing to system such as solvent or mobile phase. The developed assay method was applied to an oral pharmacokinetic study in humans and successfully characterized the pharmacokinetic data up to 72 h. Copyright © 2013 John Wiley & Sons, Ltd.     

Bistable dynamic coordination polymer showing reversible structural and functional transformations

A bistable dynamic coordination polymer [Ni(pca)(bdc)(0.5)(H(2)O)(2)] having a two-dimensional (2D) zigzag sheet structure is synthesized solvothermally. Topological analysis revealed that the frameworks have an hcb type of uninodal net. The compound exhibits guest specific reversible structural transformations accompanying reversible changes in physical properties driven by inherent flexibility and transformability.     

Palladium(II) complex with a potential N4-type Schiff-base ligand as highly efficient catalyst for Suzuki-Miyaura reactions in aqueous media

Two new air-stable palladium(II) complexes containing a N₄-Schiff-base ligand have been synthesized and investigated as catalysts for the Suzuki-Miyaura reactions. The binuclear complex 2 has proven to be an excellent catalyst for additive-free Suzuki-Miyaura reactions of aryl bromides in neat water at room temperature and aryl chlorides in aqueous-glycerol at 80 °C. Satisfactory to excellent yields of biaryls are obtained with a wide range of substrates with relatively low loading of catalyst.     

Synthesis, Characterization and Antiproliferative Activity of 1,2-Naphthoquinone and Its Derivatives

In the present study substituted 1,2-naphthoquinones were synthesized, purified and characterized by spectroscopic studies (UV, FT-IR, ¹H NMR, ¹³?C NMR and elemental analysis). These compounds were evaluated for cytotoxicity against a panel of human cancer cell lines (Hep-G₂ for liver sarcoma_, MG-63 for osteosarcoma and MCF-7 for human breast cancer). The cells were dosed with these ortho-naphthoquinone derivatives at varying concentrations, and cell viability was measured by a 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay with doxorubicin as positive control. Significant anticancer activities were observed in vitro for some members of the series, and compounds 1,2-naphthoquinone 2-thiosemicarbazone (3), 1,2-naphthoquinone-2-semicarbazone (4), 4-amino-1,2-naphthoquinone 2-thiosemicarbazone (7) and 4-amino-1,2-naphthoquinone-2-semicarbazone (8) are active cytotoxic agents against different cancer cell lines with IC₅₀ values in the range of 5.73?C17.67???M. The obtained data suggested that better anticancer activity was linked with introduction of thiosemicarbazone and semicarbazone moiety in 1,2-naphthoquinone ring system. Outcomes of experimentation also reveal that incorporation of amino group in 1,2-naphthoquinone moiety contributes positively for cytotoxic action of compounds. Docking experiments showed a good correlation between their calculated interaction energies with the topoisomerase-II and the observed IC₅₀ values of all these compounds.