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101.
Synthesis, Characterization and Antiproliferative Activity of 1,2-Naphthoquinone and Its Derivatives
S. Shukla R. S. Srivastava S. K. Shrivastava A. Sodhi Pankaj Kumar 《Applied biochemistry and biotechnology》2012,167(5):1430-1445
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. 相似文献
102.
Anil K. Shrivastava S. G. Tandon 《International journal of environmental analytical chemistry》2013,93(3-4):169-176
Abstract The method incorporates coprecipitation of lead on zirconium hydroxide and its quantitative spectrophotometric determination in natural, polluted and synthetic water samples. The method incorporates coprecipitation of lead on zirconium hydroxide and its quantitative determination by AAS using 283.3 nm wavelength. 相似文献
103.
R. N. Patel Nripendra Singh R. P. Shrivastava K. K. Shukla P. K. Singh 《Journal of Chemical Sciences》2002,114(2):115-124
Equilibrium and solution structural study of mixed-metal-mixed-ligand complexes of Cu(II), Ni(II) and Zn(II) with L-cysteine,
L-threonine and imidazole are conducted in aqueous solution by potentiometry and spectrophotometry. Stability constants of
the binary, ternary and quaternary complexes are determined at 25 ±1°C and in I= 0.1 M NaClO4. The results of these two methods are made selfconsistent, then rationalized assuming an equilibrium model including the
species H3A, H2A, A, BH, B, M(OH), M(OH)2, M(A), MA(OH), M(B), M(A)(B), M2(A)2(B), M2(A)2(B-H), M1M2(A)2(B) and M1M2(A)2(B-H) (where the charges of the species have been ignored for the sake of simplicity) (A = L-cysteine, L-threonine, salicylglycine,
salicylvaline and BH = imidazole). Evidence of the deprotonation of BH ligand is available at alkalinepH. N1H deprotonation of the bidentate coordinated imidazole ligand in the binuclear species atpH > 70 is evident from spectral measurements. Stability constants of binary M(A), M(B) and ternary M(A)(B) complexes follow
the Irving-Williams order. 相似文献
104.
The cis-dioxomolybdenum complexes MoO2(L) (L = HPD, APAC, AAC, ACEN and APS) have been synthesized and characterized. The epoxidation of olefins has been studied using these molybdenum complexes as catalysts and tert-butylhydroperoxide (TBHP) as oxidant. The studies suggest that these complexes, except [MoO2(APAC)], did not demetallate during the reaction. 相似文献
105.
Rosli AN Zabidi NA Kassim HA Shrivastava KN 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1251-1255
We have calculated the vibrational frequencies of clusters of atoms from the first principles by using the density-functional theory in the local density approximation (LDA). We are also able to calculate the electronic binding energy for all of the clusters of atoms from the optimized structure. We have made clusters of BanOm (n, m=1-6) and have determined the bond lengths, vibrational frequencies as well as intensities in each case. We find that the peroxide cluster BaO2 occurs with the O-O vibrational frequency of 836.3 cm(-1). We also find that a glass network occurs in the material which explains the vibrational frequency of 67 cm(-1). The calculated values agree with those measured from the Raman spectra of barium peroxide and Ba-B-oxide glass. We have calculated the vibrational frequencies of BaO4, GeO4 and SiO4 each in tetrahedral configuration and find that the vibrational frequencies in these systems depend on the inverse square root of the atomic mass. 相似文献
106.
Studies on speciation have been done in the mixtures of mixed ligand copper complexes. Three heterogeneous mixtures have been studied, each having one Cu(I) complex and one Cu(II) complex. The Cu(I) complex is [Cu(thu)Cl 0.5H2O] (1) and the Cu(II) complexes are [Cu(L-phen)(bpy) H2O] (2), [Cu(L-tyr)(phn) 2.5H2O] (3), and [Cu(dien)(ina) 4H2O.1/2SO4] (4) (where thu = thiourea, phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine, tyr = tyrosine, dien = diethylenetriamine, and ina = isonicotinate anion). The mixtures have been prepared by mixing the Cu(I) complex with each of the Cu(II) complexes in the ratio of 1:1 by mole percentage. The X-ray absorption fine structure (XAFS) spectra have been recorded at the K-edge of copper in the mixtures as well as in the complexes, separately. The aim of the present work is to make a study of the different methods of speciation using XAFS, viz., principal component analysis (PCA) and the target transformation (TT) method, the linear combination fitting (LCF) method, derivative spectra methods, and normalized difference absorption edge spectra (NDAES) analysis. It has been shown that these methods can be used to determine the relative quantity of the mixed ligand complexes in their mixtures. 相似文献
107.
Nickel oxide thin films were successfully fabricated with various deposition time (td = 5, 10, and 15 min) on glass substrates using spray pyrolysis technique. The deposited films undergo thermal treatment at 350 °C for various annealing time (ta = 0, 15, 30 and 60 min). In this study, the effect of td and ta on film thickness was observed and their influence on structural, morphological and optical properties were investigated. The films deposited with td = 5 min showed amorphous structure while the films grown at higher deposition time became partially crystallized with preferred growth along (1 1 1) direction. Heat treatment carried out in air allowed us to tune the polycrystalline structure and the diffraction intensity at preferred peak increases with the increase in ta which is a consequence of better crystallinity. This was reflected in the AFM micrographs of the films which suggested that the thermal annealing (or increasing ta) facilitates the process of grain-growth, and improves the crystalline microstructure. The optical transmission of the films was found to vary with td and ta and thus film thickness. The thinner films show higher transparency in the UV–vis spectral region. The optical band gap was blue-shifted from 3.35 eV to 3.51 eV depending on ta. The effect of ta on the various optical constants of the NiO films has also been discussed. 相似文献
108.
X‐ray absorption fine structure (XAFS) of aqua (diethylenetriamine) (isonicotinato) copper(II) complex has been investigated. The crystal structure of the complex is unavailable. The X‐ray absorption near edge structure (XANES) spectrum of the complex has been compared with those of the standard compounds to estimate the coordination geometry and oxidation state of copper. This study indicates that the copper center has +2 oxidation state and that it may be penta or hexa‐coordinated. The spectrum has been further compared with those of the earlier studied complexes having square‐pyramidal geometry. Similarity has been observed between them indicating that the complex should have penta‐coordinated square‐pyramidal geometry. The same inference has been obtained from the study of the characteristic pre‐edge and XANES features. This inference has been further examined by analysis of the extended X‐ray absorption fine structure (EXAFS) spectrum. The experimental EXAFS data has been fitted with three different theoretical models for tetra‐coordination, penta‐coordination, and hexa‐coordination. The tetra model is unable to provide a satisfactory fit so it has been ignored. Although the penta and hexa models give comparable results, the parameters obtained indicate that the penta‐coordinated model fits better to the experimental data than the hexa‐coordinated model. This penta‐coordinated model has been further fitted to the experimental data by allowing the coordination number to vary. Such fitting also shows that the penta‐coordinated model is a satisfactory model for the studied complex. The obtained values of mean‐square disorder indicate that the force constants are different for the equatorial and axial bonds. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
109.
Abstract The solid solution of Na1 + x
Zr2 − x
Sb
x
P3O12 (x = 0.1) was prepared at 1,000 °C by ceramic route. The ceramic material belonging to sodium zirconium phosphate (hereafter
NZP) family crystallizes in space group R-3c with unit cell parameters: a = b = 8.77283(16) ?, c = 22.8375(7) ?, α = β = 90.0° γ = 120.0° and Z = 6. The structure of the title phase has been determined by Rietveld refinement of the powder diffraction data on GSAS software.
The refinement converges to a satisfactory structure fit with R
p = 0.0764, R
wp = 0.1099 and RF
2 = 0.0450. The interatomic distances and bond angles are in good agreement with their standard values. The particle size along
prominent reflecting planes ranges between 13 and 50 nm. The polyhedral (ZrO6 and PO4 and NaO8) distortions and valence calculations from bond strength data are also reported. The investigations show that the Sb+3 cation occupies the zirconium (AVI) site of NZP structural framework and resultant charge compensation takes place through partial occupation of M2 site by Na+ ions.
Index Abstract Synthesis and Structure Refinement of Polycrystalline Solid Solution: Na1 + x
Zr
2 − x
Sb
x
P
3
O
12
(
x
= 0.1)
O. P. Shrivastava and Rashmi Chourasia
Antimony enters crystallochemically in the framework of nano ceramic sodium zirconium phosphate at the Zr site of the ZrO6 octahedra which are inter linked by PO4 tetrahedra through corner sharing of the vertical columns.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
110.
V. V. Parkar V. Jha S. Santra B. J. Roy K. Ramachandran A. Shrivastava K. Mahata A. Chatterjee S. Kailas 《Pramana》2009,72(2):363-373
The elastic scattering and the 6He angular distributions were measured in 7Li + 7Li reaction at two energies, E
lab = 20 and 25 MeV. FRDWBA calculations have been performed to explain the measured 6He data. The calculations were very sensitive to the choice of the optical model potentials in entrance and exit channels.
The one-step proton transfer was found to be the dominant reaction mechanism in 6He production.
相似文献