Synthesis, characterization and biological activity of novel Cu(II) complexes of 6-methyl-2-oxo-1,2-dihydroquinoline-3-carbaldehy de-4N-substituted thiosemicarbazones

Three new 6-methyl-2-oxo-1,2-dihydroquinoline-3-carbaldehyde-thiosemicarbazones-N-4-substituted pro-ligands and their Cu(II) complexes (1, -NH2; 2, -NHMe; 3, -NHEt) have been prepared and characterized. In both the X-ray structures of 1 and 3, two crystallographically independent complex molecules were found that differ either in the nature of weakly metal-binding species (water in 1a and nitrate in 1b) or in the co-ligand (water in 3a and methanol in 3b). Electron Paramagnetic Resonance (EPR) measurements carried out on complexes 1 and 3 confirmed the presence of such different species in the solution. The electrochemical behavior of the pro-ligands and of the complexes was investigated, as well as their biological activity. Complexes 2 and 3 exhibited a high cytotoxicity against human tumor cells and 3D spheroids derived from solid tumors, related to the high cellular uptake. Complexes 2 and 3 also showed a high selectivity towards cancerous cell lines with respect to non-cancerous cell lines and were able to circumvent cisplatin resistance. Via the Transmission Electron Microscopy (TEM) imaging technique, preliminary insights into the biological activity of copper complexes were obtained

Path optimization using fuzzy distance approach

The main objective of this paper is to optimize the Web-surfing, i.e., to find the optimal path set leading to a target page in a specific Web site with links to other domains. The frequency of accessing various links (access rate), and the time taken to retrieve target pages (retrieval rate) are considered as decisive factors. The access and the retrieval rate are affected by many factors like availability of channels, server capability, the accessing time etc., and are changing periodically. The expected access rate and the required retrieval rate are expressed as fuzzy sets. All paths are identified between the source and destination pages. Users' opinions are collected on each path that leads to target page according to their experience while surfing with regard to access rate and retrieval rate, and a fuzzy opinion matrix is formulated. From the overall fuzzy opinion on each link in a path, a fuzzy Hurwicz opinion set is derived using an optimism-pessimism index. The fuzzy distance between this opinion set and the actual requirement set is estimated. The path that yields minimum fuzzy distance is considered as the optimal path from the source to the destination

Web navigation efficiency analysis

The main objective of this paper is to analyze the current users' surfing behavior and propose efficient web navigation models for the naive users as well as experienced users. Pre-order surfing and Hamiltonian surfing are recommended for naive users since they are unfamiliar with the web sites considered. Conversely, optimal path surfing should be explored for the experienced users since their target pages have been pre-defined. Path optimization using fuzzy distance approach is proposed to compromise various criterions and identify the optimal path or sub-optimal path to a specific target pag

Evaluation of DNA binding, antioxidant and cytotoxic activity of mononuclear Co(III) complexes of 2-oxo-1,2-dihydrobenzoh]quinoline-3-carbaldehyde thiosemicarbazones

Four new 2-oxo-1,2-dihydrobenzoh]quinoline-3-carbaldehyde N-substituted thiosemicarbazone ligands (H-2-LR, where R = H, Me, Et or Ph) and their corresponding new cobalt(III) complexes have been synthesized and characterized. The structures of the complexes 2 and 3 were determined by single crystal X-ray diffraction analysis. The interactions of the new complexes with DNA were investigated by absorption, emission and viscosity studies which indicated that the complexes bind to DNA via intercalation. Antioxidant studies of the new complexes showed that the significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of complexes 1-4 against A549 cell line was assayed which showed higher cytotoxic activity with lower IC50 values indicating their efficiency in killing the cancer cells even at very low concentrations. (C) 2012 Elsevier Masson SAS. All rights reserved

Synthesis, X-ray crystal structure, DNA binding, antioxidant and cytotoxicity studies of Ni(II) and Pd(II) thiosemicarbazone complexes

New complexes, [Ni(HL)(PPh3)]Cl (1), [Pd(L)(PPh3)](2), and [Pd(L)(AsPh3)](3), were synthesized from the reactions of 4-chloro-5-methyl-salicylaldehyde thiosemicarbazone [H2L] with [NiCl2(PPh3)(2)], [PdCl2(PPh3)(2)] and [PdCl2(AsPh3)(2)]. They were characterized by IR, electronic, H-1-NMR spectral data. Further, the structures of the complexes have been determined by single crystal X-ray diffraction. While the thiosemicarbazone coordinated as binegative tridentate (ONS) in complexes 2 and 3, it is coordinated as mono negative tridentate (ONS) in 1. The interactions of the new complexes with calf thymus DNA was examined by absorption and emission spectra, and viscosity measurements. Moreover, the antioxidant properties of the new complexes have also been tested against DPPH radical in which complex 1 exhibited better activity than that of the other two complexes 2 and 3. The in vitro cytotoxicity of complexes 1-3 against A549 and HepG2 cell lines was assayed, and the new complexes exhibited higher cytotoxic activity with lower IC50 values indicating their efficiency in killing the cancer cells even at very low concentrations

High-Temperature, High-Pressure Hydrothermal Synthesis, Characterization, and Structural Relationships of Layered Uranyl Arsenates

Five new uranyl arsenates, Na₁₄[(UO₂)₅(AsO₄)₈]·2H₂O (<b>1</b>), K₆[(UO₂)₅O₅(AsO₄)₂] (<b>2a</b>), K₄[(UO₂)₃O₂(AsO₄)₂] (<b>2b</b>), Rb₄[(UO₂)₃O₂(AsO₄)₂] (<b>3</b>), and Cs₆[(UO₂)₅O₂(AsO₄)₄] (<b>4</b>), were synthesized by high-temperature, high-pressure hydrothermal reactions at about 560 °C and 1440 bar and were characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and photoluminescence spectroscopy. Crystal data for compound <b>1</b>: triclinic, <i>P</i>1̅, <i>a</i> = 7.0005(3) Å, <i>b</i> = 12.1324(4) Å, <i>c</i> = 13.7428(5) Å, α = 64.175(2)°, β = 89.092(2)°, γ = 85.548(2)°, <i>V</i> = 1047.26(7) ų, <i>Z</i> = 1, <i>R</i>1 = 0.0185; compound <b>2a</b>: monoclinic, <i>P</i>2₁/<i>c</i>, <i>a</i> = 6.8615(3) Å, <i>b</i> = 24.702(1) Å, <i>c</i> = 7.1269(3) Å, β = 98.749(2)°, <i>V</i> = 1193.89(9) ų, <i>Z</i> = 2, <i>R</i>1 = 0.0225; compound <b>2b</b>: monoclinic, <i>P</i>2₁/<i>c</i>, <i>a</i> = 6.7852(3) Å, <i>b</i> = 17.3640(8) Å, <i>c</i> = 7.1151(3) Å, β = 98.801(3)°, <i>V</i> = 828.42(6) ų, <i>Z</i> = 2, <i>R</i>1 = 0.0269; compound <b>3</b>: monoclinic, <i>P</i>2₁/<i>m</i>, <i>a</i> = 6.9783(3) Å, <i>b</i> = 17.4513(8) Å, <i>c</i> = 7.0867(3) Å, β = 90.808(3)°, <i>V</i> = 862.94(7) ų, <i>Z</i> = 2, <i>R</i>1 = 0.0269; compound <b>4</b>: triclinic, <i>P</i>1̅, <i>a</i> = 7.7628(3) Å, <i>b</i> = 9.3324(4) Å, <i>c</i> = 11.9336(4) Å, α = 75.611(2)°, β = 73.136(2)°, γ = 86.329(2)°, <i>V</i> = 801.37(5) ų, <i>Z</i> = 1, <i>R</i>1 = 0.0336. The five compounds have layer structures consisting of uranyl square, pentagonal, and hexagonal bipyramids as well as AsO₄ tetrahedra. Compound <b>1</b> contains chains of discrete uranyl square and pentagonal bipyramids, <b>2a</b> contains three-polyhedron-wide ribbons of edge- and corner-sharing uranyl square and pentagonal bipyramids, <b>2b</b> and <b>3</b> contain dimers of edge-shairing pentagonal bipyramids that share edges with hexagonal bipyramids to form chains, and <b>4</b> contains one-polyhedron-wide zigzag chains of edge-sharing uranyl polyhedra. The double sheet structure of <b>1</b> is new, but the chain topology has been observed in an organically templated uranyl sulfate. Compound <b>2b</b> is a new geometrical isomer of the phosphuranylite group. The sheet anion topologies of <b>2a</b> and <b>4</b> can be obtained by splitting the β-U₃O₈-type sheet into complex chains and connecting the chains by arsenates

High-Temperature, High-Pressure Hydrothermal Synthesis, Characterization, and Structural Relationships of Layered Uranyl Arsenates

Five new uranyl arsenates, Na₁₄[(UO₂)₅(AsO₄)₈]·2H₂O (<b>1</b>), K₆[(UO₂)₅O₅(AsO₄)₂] (<b>2a</b>), K₄[(UO₂)₃O₂(AsO₄)₂] (<b>2b</b>), Rb₄[(UO₂)₃O₂(AsO₄)₂] (<b>3</b>), and Cs₆[(UO₂)₅O₂(AsO₄)₄] (<b>4</b>), were synthesized by high-temperature, high-pressure hydrothermal reactions at about 560 °C and 1440 bar and were characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and photoluminescence spectroscopy. Crystal data for compound <b>1</b>: triclinic, <i>P</i>1̅, <i>a</i> = 7.0005(3) Å, <i>b</i> = 12.1324(4) Å, <i>c</i> = 13.7428(5) Å, α = 64.175(2)°, β = 89.092(2)°, γ = 85.548(2)°, <i>V</i> = 1047.26(7) ų, <i>Z</i> = 1, <i>R</i>1 = 0.0185; compound <b>2a</b>: monoclinic, <i>P</i>2₁/<i>c</i>, <i>a</i> = 6.8615(3) Å, <i>b</i> = 24.702(1) Å, <i>c</i> = 7.1269(3) Å, β = 98.749(2)°, <i>V</i> = 1193.89(9) ų, <i>Z</i> = 2, <i>R</i>1 = 0.0225; compound <b>2b</b>: monoclinic, <i>P</i>2₁/<i>c</i>, <i>a</i> = 6.7852(3) Å, <i>b</i> = 17.3640(8) Å, <i>c</i> = 7.1151(3) Å, β = 98.801(3)°, <i>V</i> = 828.42(6) ų, <i>Z</i> = 2, <i>R</i>1 = 0.0269; compound <b>3</b>: monoclinic, <i>P</i>2₁/<i>m</i>, <i>a</i> = 6.9783(3) Å, <i>b</i> = 17.4513(8) Å, <i>c</i> = 7.0867(3) Å, β = 90.808(3)°, <i>V</i> = 862.94(7) ų, <i>Z</i> = 2, <i>R</i>1 = 0.0269; compound <b>4</b>: triclinic, <i>P</i>1̅, <i>a</i> = 7.7628(3) Å, <i>b</i> = 9.3324(4) Å, <i>c</i> = 11.9336(4) Å, α = 75.611(2)°, β = 73.136(2)°, γ = 86.329(2)°, <i>V</i> = 801.37(5) ų, <i>Z</i> = 1, <i>R</i>1 = 0.0336. The five compounds have layer structures consisting of uranyl square, pentagonal, and hexagonal bipyramids as well as AsO₄ tetrahedra. Compound <b>1</b> contains chains of discrete uranyl square and pentagonal bipyramids, <b>2a</b> contains three-polyhedron-wide ribbons of edge- and corner-sharing uranyl square and pentagonal bipyramids, <b>2b</b> and <b>3</b> contain dimers of edge-shairing pentagonal bipyramids that share edges with hexagonal bipyramids to form chains, and <b>4</b> contains one-polyhedron-wide zigzag chains of edge-sharing uranyl polyhedra. The double sheet structure of <b>1</b> is new, but the chain topology has been observed in an organically templated uranyl sulfate. Compound <b>2b</b> is a new geometrical isomer of the phosphuranylite group. The sheet anion topologies of <b>2a</b> and <b>4</b> can be obtained by splitting the β-U₃O₈-type sheet into complex chains and connecting the chains by arsenates

Synthesis, characterization and cytotoxic activity of novel copper(II) complexes with aroylhydrazone derivatives of 2-Oxo-1,2-dihydrobenzo[h]quinoline-3-carbaldehyde

Three new 2-oxo-1,2-dihydrobenzo[h]quinoline-3-carbaldehyde terminal substituted aroylhydrazone ligands (2-Oxo-1,2-dihydrobenzo[h]quinoline-3-carbaldehyde(2\u2032-hydroxybenzoyl)hydrazine, H2L1, 1, 2-Oxo-1,2-dihydrobenzo[h]quinoline-3-carbaldehyde(2\u2032-hydroxybenzoyl)hydrazine, H2L2, 2, 2-Oxo-1,2-dihydrobenzo[h]quinoline-3-carbaldehyde(2\u2032-hydroxybenzoyl)hydrazine, H2L3, 3) and the corresponding novel copper(II) complexes [Cu(L)(CH3OH)(NO3)](L = HL1 (4), HL2 (5), HL3 (6-6+), have been synthesized to compare their coordination behaviour and biological activity with respect to the presence of an OH group in different positions of the phenyl ring in the hydrazone moieties. The new ligands and their copper complexes were characterized by elemental analysis and spectroscopic techniques. The molecular structures of the new complexes 4 and 6-6+ were determined by single crystal X-ray diffraction. The interactions of the free ligands and their copper complexes with calf thymus DNA were tested by absorption measurements and ethidium bromide competitive studies which revealed that all compounds may interact with calf thymus DNA through intercalation. Furthermore, a comparative analysis of the cytotoxic effect of the compounds on a panel of human cancer cell lines showed that the copper complexes exhibited in vitro antitumor activity significantly higher than that of the free ligands and also of cisplatin

An analysis of declining incidence of regular labour contracts in rural India

Evidence obtained from the ICRISAT villages in India suggests that the decline of regular contracts has been accompanied by the growth in real wages and casualisation of the rural labour force. In view of this evidence, the article examines the causes of the declining incidence of regular contracts in rural India. We argue that this has been caused by the leftward shift in the regular labour supply curve due to improved employment and credit opportunities and not an upward movement of the labour demand curve as manifested by the increase in real wages over the years.