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1.  DNA Cleavage, Cytotoxic Activities, and Antimicrobial Studies of Ternary Copper(II) Complexes of Isoxazole Schiff Base and Heterocyclic Compounds 
Novel mixed ligand bivalent copper complexes [Cu. L. A. ClO4] and [Cu. L. A] where “L” is Schiff bases, namely 2-((3,4-dimethylisoxazol-5-ylimino)methyl)-4-bromophenol (DMIIMBP)/2-((3,4-dimethylisoxazol-5-ylimino)methyl)-4-chlorophenol (DMIIMCP), and “A” is heterocyclic compound, such as 1,10-phenanthroline (phen)/2,21-bipyridyl (bipy)/8-hydroxyquinoline (oxine)/5-chloro-8-hydroxyquinoline (5-Cl-oxine), have been synthesized. These complexes have been characterized by IR, UV-Vis, ESR, elemental analysis, magnetic moments, TG, and DTA. On the basis of spectral studies and analytical data, five-coordinated square pyramidal/four-coordinated square planar geometry is assigned to all complexes. The ligands and their ternary complexes with Cu(II) have been screened for antimicrobial activity against bacteria and fungi by paper disc method. The antimicrobial studies of Schiff bases and their metal complexes showed significant activity and further it is observed that the metal complexes showed more activity than corresponding Schiff bases. In vitro antitumor activity of Cu(II) complexes was assayed against human cervical carcinoma (HeLa) cancer cells and it was observed that few complexes exhibit good antitumor activity on HeLa cell lines. The DNA cleavage studies have also been carried out on pBR 322 and it is observed that these Cu(II) complexes are capable of cleaving supercoiled plasmid DNA in the presence of H2O2 and UV light.
PMCID: PMC4034397  PMID: 24895493
2.  Synthesis, Structural Characterization, and Biological Activity Studies of Ni(II) and Zn(II) Complexes 
Ni(II) and Zn(II) complexes were synthesized from tridentate 3-formyl chromone Schiff bases such as 3-((2-hydroxyphenylimino)methyl)-4H-chromen-4-one (HL1), 2-((4-oxo-4H-chromen-3-yl)methylneamino)benzoic acid (HL2), 3-((3-hydroxypyridin-2-ylimino)methyl)-4H-chromen-4-one (HL3), and 3-((2-mercaptophenylimino)methyl)-4H-chromen-4-one (HL4). All the complexes were characterized in the light of elemental analysis, molar conductance, FTIR, UV-VIS, magnetic, thermal, powder XRD, and SEM studies. The conductance and spectroscopic data suggested that, the ligands act as neutral and monobasic tridentate ligands and form octahedral complexes with general formula [M(L1–4)2]·nH2O (M = Ni(II) and Zn(II)). Metal complexes exhibited pronounced activity against tested bacteria and fungi strains compared to the ligands. In addition metal complexes displayed good antioxidant and moderate nematicidal activities. The cytotoxicity of ligands and their metal complexes have been evaluated by MTT assay. The DNA cleavage activity of the metal complexes was performed using agarose gel electrophoresis in the presence and absence of oxidant H2O2. All metal complexes showed significant nuclease activity in the presence of H2O2.
PMCID: PMC4022167  PMID: 24948904
3.  Syntheses, Characterization, Thermal, and Antimicrobial Studies of Lanthanum(III) Tolyl/Benzyldithiocarbonates 
Lanthanum(III) tris(O-tolyl/benzyldithiocarbonates), [La(ROCS2)] (R = o-, m-, p-CH3C6H4 and C6H5CH2), were isolated as yellow solid by the reaction of LaCl3·7H2O with sodium salt of tolyl/benzyldithiocarbonates, ROCS2Na (R = o-, m-, p-CH3C6H4 and C6H5CH2), in methanol under anhydrous conditions in 1 : 3 molar ratio. These complexes have formed adducts with nitrogen and phosphorus donor molecules by straightforward reaction of these complexes with donor ligands, which have the composition of the type [La(ROCS2)3·nL] (where n = 2, L = NC5H5 or P(C6H5)3 and n = 1, L = N2C12H8 or N2C10H8). Elemental analyses, mass, IR, TGA, and heteronuclear NMR (1H, 13C and 31P) spectroscopic studies indicated bidentate mode of bonding by dithiocarbonate ligands leading to hexacoordinated and octacoordinated geometry around the lanthanum atom. Antimicrobial (antifungal and antibacterial) activity of the free ligands and some of the complexes have also been investigated which exhibited significantly more activity for the complexes than the free ligands.
PMCID: PMC4000956  PMID: 24817836
4.  Reversible Dissociation and Ligand-Glutathione Exchange Reaction in Binuclear Cationic Tetranitrosyl Iron Complex with Penicillamine 
This paper describes a comparative study of the decomposition of two nitrosyl iron complexes (NICs) with penicillamine thiolic ligands [Fe2(SC5H11NO2)2(NO)4]SO4·5H2O (I) and glutathione- (GSH-) ligands [Fe2(SC10H17N3O6)2(NO)4]SO4·2H2O (II), which spontaneously evolve to NO in aqueous medium. NO formation was measured by a sensor electrode and by spectrophotometric methods by measuring the formation of a hemoglobin- (Hb-) NO complex. The NO evolution reaction rate from (I)  k1 = (4.6 ± 0.1)·10−3 s−1 and the elimination rate constant of the penicillamine ligand k2 = (1.8 ± 0.2)·10−3 s−1 at 25°C in 0.05 M phosphate buffer,  pH 7.0, was calculated using kinetic modeling based on the experimental data. Both reactions are reversible. Spectrophotometry and mass-spectrometry methods have firmly shown that the penicillamine ligand is exchanged for GS− during decomposition of 1.5·10−4 M (I) in the presence of 10−3 M GSH, with 76% yield in 24 h. As has been established, such behaviour is caused by the resistance of (II) to decomposition due to the higher affinity of iron to GSH in the complex. The discovered reaction may impede S-glutathionylation of the essential enzyme systems in the presence of (I) and is important for metabolism of NIC, connected with its antitumor activity.
PMCID: PMC3984828  PMID: 24790592
5.  Degradation of Methylene Blue Using Biologically Synthesized Silver Nanoparticles 
Nowadays plant mediated synthesis of nanoparticles has great interest and achievement due to its eco-benign and low time consuming properties. In this study silver nanoparticles were successfully synthesized by using Morinda tinctoria leaf extract under different pH. The aqueous leaf extract was added to silver nitrate solution; the color of the reaction medium was changed from pale yellow to brown and that indicates reduction of silver ions to silver nanoparticles. Thus synthesized silver nanoparticles were characterized by UV-Vis spectrophotometer. Dispersity and morphology was characterized by scanning electron microscope (SEM); crystalline nature and purity of synthesized silver nanoparticles were revealed by X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). FTIR spectrum was examined to identify the effective functional molecules responsible for the reduction and stabilization of silver nanoparticles synthesized by leaf extract. The photocatalytic activity of the synthesized silver nanoparticles was examined by degradation of methylene blue under sunlight irradiation. Green synthesized silver nanoparticles were effectively degrading the dye nearly 95% at 72 h of exposure time.
PMCID: PMC3977556  PMID: 24772055
6.  Synthesis and Spectroscopic and Biological Activities of Zn(II) Porphyrin with Oxygen Donors 
Results of investigation of the physicochemical properties of zinc complexes containing substituted phenols as axial ligand having general formula [X-Zn-t(p-CH3) PP] [where X = different phenolates as axial ligand] in impurity-free organic solvent are presented. The four-coordinated zinc porphyrin accepts one axial ligand in 1 : 1 molar ratio to form five-coordinated complex, which is purified by column chromatography and characterized by physicochemical, biological evaluation and TGA/DTA studies. Absorption spectra show two principal effects: a red shift for phenols bearing substituted electron releasing groups (−CH3, −NH2) and blue shift for phenols bearing electron withdrawing groups (−NO2, −Cl) relative to Zn-t(p-CH3) PP, respectively. 1H NMR spectra show that the protons of the phenol ring axially attached to the central metal ion are merged with the protons of the porphyrin ring. Fluorescence spectra show two fluorescence peaks in the red region with emission ranging from 550 nm to 700 nm. IR spectra confirm the appearance of Zn-NPor and Zn-O vibrational frequencies, respectively. According to the thermal studies, the complexes have a higher thermal stability and the decomposition temperature of these complexes depends on the axial ligation. The respective complexes of X-ZnII-t(p-CH3) PP were found to possess higher antifungal activity (up to 90%) and higher in vitro cytotoxicity against human cancer cells lines.
PMCID: PMC3976806  PMID: 24744692
7.  Evaluation of DNA Binding, Cleavage, and Cytotoxic Activity of Cu(II), Co(II), and Ni(II) Schiff Base Complexes of 1-Phenylindoline-2,3-dione with Isonicotinohydrazide 
One new series of Cu(II), Co(II), and Ni(II) Schiff base complexes was prepared through the condensation reaction between 1-phenylindoline-2,3-dione with isonicotinohydrazide followed by metalation, respectively. The Schiff base ligand(L), (E)-N′-(2-oxo-1-phenylindolin-3-lidene)isonicotinohydrazide, and its complexes were found soluble in DMF and DMSO solvents and characterized by using the modern analytical and spectral techniques such as elemental analysis, conductivity, magnetic moments, IR, NMR, UV-visible, Mass, CV, and EPR. The elemental analysis data of ligand and their complexes were well agreed with their calculated values in which metal and ligand stoichiometry ratio 1 : 2 was noted. Molar conductance values indicated that all the complexes were found to be nonelectrolytes. All the complexes showed octahedral geometry around the central metal ions. Herein, we better characterized DNA binding with the complexes by UV-visible and CD spectroscopy and cyclic voltammetry techniques. The DNA cleavage experiments were carried out by Agarose gel electrophoresis method and the cytotoxicity experiments by MTT assay method. Based on the DNA binding, cleavage, and cytotoxicity studies, Cu and Ni complexes were found to be good anticancer agents against AGS-human gastric cancer cell line.
PMCID: PMC3972935  PMID: 24744691
8.  (E)3-2-(1-(2,4-Dihydroxyphenyl)ethyldeneamino)phenyl)-2-methylquinazoline-4(3H)-one Schiff Base and Its Metal Complexes: A New Drug of Choice against Methicillin-Resistant Staphylococcus aureus 
The 3-(2-aminophenyl) quinazolin-2-methyl-4(3H)-one and 2,4-dihydroxyacetophenone undergo condensation to afford (E)3-2-(1-(2,4-dihydroxyphenyl)ethyldeneamino)phenyl)-2-methylquinazoline-4(3H)-one Schiff base (DHPEAPMQ). The newly synthesized Schiff base (DHPEAPMQ) and its metal complexes were evaluated for their antimicrobial activity against methicillin-resistant Staphylococcus aureus isolated from the Gulbarga region in India. The Cu(II), Ni(II), and Zn(II) complexes of Schiff base (DHPEAPMQ) showed good antimicrobial activity. So, this could be a new drug of choice.
PMCID: PMC3966480  PMID: 24733996
9.  Synthesis, Characterization, Antimicrobial, DNA Cleavage, and In Vitro Cytotoxic Studies of Some Metal Complexes of Schiff Base Ligand Derived from Thiazole and Quinoline Moiety 
A novel Schiff base ligand N-(4-phenylthiazol-2yl)-2-((2-thiaxo-1,2-dihydroquinolin-3-yl)methylene)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-thioxo-1,2-dihydroquinoline-3-carbaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), and Zn(II) complexes have been characterized by elemental analysis and various spectral studies like FT-IR, 1H NMR, ESI mass, UV-Visible, ESR, TGA/DTA, and powder X-ray diffraction studies. The Schiff base ligand (L) behaves as tridentate ONS donor and forms the complexes of type [ML(Cl)2] with square pyramidal geometry. The Schiff base ligand (L) and its metal complexes have been screened in vitro for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activity of ligand and its metal complexes were studied using plasmid DNA pBR322 as a target molecule by gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties for the ligand and its metal complexes against Artemia salina. The results showed that the biological activities of the ligand were found to be increased on complexation.
PMCID: PMC3960517  PMID: 24729778
10.  Biosynthesis and Antimicrobial Activity of Semiconductor Nanoparticles against Oral Pathogens 
Dental care is an essential phenomenon in human health. Oral pathogens can cause severe break which may show the way to serious issues in human disease like blood circulation and coronary disease. In the current study, we demonstrated the synthesis and antimicrobial activity of cadmium sulphide and zinc sulphide nanoparticles against oral pathogens. The process for the synthesis of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles is fast, novel, and ecofriendly. Formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was confirmed by surface plasmon spectra using UV-Vis spectrophotometer. The morphology of crystalline phase of nanoparticles was determined from transmission electron microscopy (TEM) and X-ray diffraction (XRD) spectra. The average size of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was in the range of 10 nm to 25 nm and 65 nm, respectively, and the observed morphology was spherical. The results indicated that the proteins, which contain amine groups, played a reducing and controlling responsibility during the formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles in the colloidal solution. The antimicrobial activity was assessed against oral pathogens such as Streptococcus sp. Staphylococcus sp. Lactobacillus sp., and Candida albicans and these results confirmed that the sulphide nanoparticles are exhibiting good bactericidal activity.
PMCID: PMC4016845  PMID: 24860280
11.  Synthesis, Spectral Characterization, and Antiproliferative Studies of Mixed Ligand Titanium Complexes of Adamantylamine 
Titanium complexes have been synthesized by the reaction between titanium tetrachloride (TiCl4), respective bidentate ligand [4,4′ -dimethoxy-2,2′ -bipyridine (bpome), 6,6′-dimethyl-2,2′-bipyridine (dpme), 1,2-diaminocyclohexane (dach), 1,10-phenanthroline (phen), and benzoylacetone (bzac)], and adamantylamine (ada) in 1 : 2 : 2 molar ratios, respectively. The structure of synthesized complexes was confirmed using elemental analysis, FTIR, UV-visible, 1H NMR, and mass spectrometry techniques. The nanocrystalline nature of complexes was confirmed by powder XRD study. The complexes were evaluated for cytotoxic potential in HeLa (cervical), C6 (glioma), and CHO (Chinese hamster ovarian) cell lines. The complex E was found to be more effective cytotoxic agent against HeLa cell line with an IC50 value of 4.06 µM. Furthermore, the effect of synthesized complexes was studied on different stages of the cell cycle in CHO cells. All complexes exhibited the dose dependent increase in cytotoxicity. The results have shown an increase in sub-G0 population with increase in concentration which is an indicative measure of apoptosis.
PMCID: PMC3955668  PMID: 24715822
12.  Novel Zinc(II) Complexes of Heterocyclic Ligands as Antimicrobial Agents: Synthesis, Characterisation, and Antimicrobial Studies 
The synthesis and antimicrobial activity of novel Zn(II) metal complexes derived from three novel heterocyclic Schiff base ligands 8-[(Z)-{[3-(N-methylamino)propyl]imino}methyl]-7-hydroxy-4-methyl-2H-chromen-2-one, 2-[(E)-{[4-(1H-1,2,4-triazol-1-ylmethyl)phenyl]imino}methyl]phenol, and (4S)-4-{4-[(E)-(2-hydroxybenzylidene)amino]benzyl}-1,3-oxazolidin-2-one have been described. These Schiff base ligands and metal complexes are characterised by spectroscopic techniques. According to these data, we propose an octahedral geometry to all the metal complexes. Antimicrobial activity of the Schiff base ligand and its metal complexes was studied against Gram negative bacteria: E. coli and Pseudomonas fluorescens, Gram positive bacteria: Staphylococcus aureus, and also against fungi, that is, C. albicans and A. niger. Some of the metal complexes show significant antifungal activity (MIC < 0.2 μg/mL). The “in vitro” data has identified [Zn(NMAPIMHMC)2]·2H2O, [Zn(TMPIMP)2]·2H2O, and [Zn(HBABO)2]·2H2O as potential therapeutic antifungal agents against C. albicans and A. niger.
PMCID: PMC3953498  PMID: 24707242
13.  Temporal Changes in Concentrations of Some Trace Elements in Muscle Tissue of Crayfish, Astacus leptodactylus (Eschscholtz, 1823), from Keban Dam Lake 
Crayfish (Astacus leptodactylus Eschscholtz, 1823) is the native crayfish species in Turkey. It was exported regularly to Western Europe. In this study, bioaccumulation and temporal trends of some trace elements (arsenic: As, cadmium: Cd, copper: Cu, mercury: Hg, lead: Pb, and zinc: Zn) in edible abdomen muscle of crayfish from Keban Dam Lake (Elazığ, Turkey) were investigated for the 2006–2012 period. Sequence of metal concentration levels was Zn > Cu > Hg > Pb > Cd > As in muscle tissues. The highest concentration of Zn (21.69 mg kg−1) was detected in 2006, while the lowest (4.35 mg kg−1) in 2009. In general, it was found that the concentrations of trace elements investigated were lower than the maximum permissible limits of the food regulations of the Ministry of Food, Agriculture, and Livestock (MFAL), the Turkish Food Codex and Commission Regulation (EC). If the crayfish selected for the study are recognized as bioindicators of environmental pollution, then it is possible to conclude that the changes in studied trace elements concentrations in the Keban Dam Lake are being steady.
PMCID: PMC3953500  PMID: 24707241
14.  Synthesis and Crystal Structure of the Bioinorganic Complex [Sb(Hedta)]·2H2O 
The antimony(III) complex [Sb(Hedta)]·2H2O was synthesized with ethylenediaminetetraacetic acid (H4edta) and antimonous oxide as main raw materials in aqueous solution. The composition and structure of the complex were characterized by elemental analysis, infrared spectra, single crystal X-ray diffraction, X-ray powder diffraction, thermogravimetry, and differential scanning calorimetry. The crystal structure of the antimony(III) complex belongs to orthorhombic system, space group Pna2(1), with cell parameters of a = 18.4823(18) Å, b = 10.9408(12) Å, c = 7.3671(5) Å, V = 1489.7(2) Å3, Z = 4, and Dc = 1.993 g cm−3. The Sb(III) ion is five-coordinated by two amido N atoms and three carboxyl O atoms from a single Hedta3− ligand, forming a distorted trigonal bipyramid geometry. The thermal decomposition processes of the complex include dehydration, oxidation, and pyrolysis of the ligand, and the last residue is Sb2O3 at the temperature of 570°C.
PMCID: PMC3943296  PMID: 24683384
15.  Transition Metal(II) Complexes with Cefotaxime-Derived Schiff Base: Synthesis, Characterization, and Antimicrobial Studies 
New [ML2(H2O)2] complexes, where M = Co(II), Ni(II), Cu(II), and Zn(II) while L corresponds to the Schiff base ligand, were synthesized by condensation of cefotaxime with salicylaldehyde in situ in the presence of divalent metal salts in ethanolic medium. The complexes were characterized by elemental analyses, conductance, and magnetic measurements, as well as by IR and UV-Vis spectroscopy. The low values of the molar conductance indicate nonelectrolyte type of complexes. Based on spectral data and magnetic moments, an octahedral geometry may be proposed for Co(II), Ni(II), and Zn(II) complexes while a tetragonal geometry for Cu(II) complex. Molecular structure of the Schiff base ligand and its complexes were studied using programs dedicated to chemical modeling and quantomolecular calculation of chemical properties. All the synthesized complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, namely Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains revealed that the metal complexes possess superior antibacterial activity than the Schiff base.
PMCID: PMC3944908  PMID: 24688454
16.  Optimization and Characterization of Silver Nanoparticle by Endophytic Fungi Penicillium sp. Isolated from Curcuma longa (Turmeric) and Application Studies against MDR E. coli and S. aureus 
Development of ecofriendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology because of its tremendous impetus in modulating metals into nanosize to their potential use for human benefits. In this study an endophytic fungus, Penicillium sp., isolated from healthy leaves of Curcuma longa (turmeric) was subjected to extracellular biosynthesis of silver nanoparticles (AgNps) and their activity against MDR E. coli and S. aureus. The biosynthesized AgNps optimization was studied and characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). Then produced AgNps were tested against MDR E. coli and S. aureus. The endophytic fungus Penicillium sp. from healthy leaves of C. longa (turmeric) was found to be a good producer of AgNps. Parametric optimization showed maximum absorbance of 420–425 nm at pH-7, 25°C with 1 mM AgNO3 concentration and 15–20 g of wet biomass. Further TEM revealed the formation of spherical, well-dispersed nanoparticles with size ranging between 25 and 30 nm and FTIR shows the bands at 1644 and 1538 cm−1 corresponding to the binding vibrations of amide I and II bands of proteins, respectively. Antibacterial activity against MDR E. coli and S. aureus showed good results showing maximum zone of inhibition of 17 mm and 16 mm, respectively, at 80 µL of AgNps.
PMCID: PMC3930180  PMID: 24639625
17.  Metal (II) Complexes Derived from Naphthofuran-2-carbohydrazide and Diacetylmonoxime Schiff Base: Synthesis, Spectroscopic, Electrochemical, and Biological Investigation 
A new Schiff base and a new series of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) complexes were synthesized by the condensation of naphthofuran-2-carbohydrazide and diacetylmonoxime. Metal complexes of the Schiff base were prepared from their chloride salts of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) in ethanol. The ligand along with its metal complexes have been characterized on the basis of analytical data, IR, electronic, mass, 1HNMR, ESR spectral data, thermal studies, magnetic susceptibility, and molar conductance measurements. The nonelectrolytic behaviour of the complexes was assessed from the measured low conductance data. The elemental analysis of the complexes confirm the stoichiometry of the type CuL2Cl2 and MLCl2 where M = Ni(II), Co(II), Cd(II), and Hg(II) and L = Schiff base. The redox property of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In the light of these results, Co(II), Ni(II), and Cu(II) complexes are assigned octahedral geometry, Cd(II), and Hg(II) complexes tetrahedral geometry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleaving capacity of all the complexes was analysed by agarose gel electrophoresis method.
PMCID: PMC3926296  PMID: 24592203
18.  Sonochemical Synthesis of Silver Nanoparticles Using Starch: A Comparison 
A novel approach was applied to synthesize silver nanoparticles using starch under sonication. Colloidal silver nanoparticles solution exhibited an increase of absorption from 420 to 440 nm with increase starch quantity. Transmission electron microscopy followed by selected area electron diffraction pattern analysis indicated the formation of spherical, polydispersed, amorphous, silver nanoparticles of diameter ranging from 23 to 97 nm with mean particle size of 45.6 nm. Selected area electron diffraction (SAED) confirmed partial crystalline and amorphous nature of silver nanoparticles. Silver nanoparticles synthesized in this manner can be used for synthesis of 2-aryl substituted benzimidazoles which have numerous biomedical applications. The optimized reaction conditions include 10 ml of 1 mM AgNO3, 25 mg starch, 11 pH range, and sonication for 20 min at room temperature.
PMCID: PMC3920662  PMID: 24587771
19.  Preparation of Nanosilver and Nanogold Based on Dog Rose Aqueous Extract 
This paper describes a process of obtaining nanosilver and nanogold based on chemical reduction using substances contained in the aqueous extract of dog rose (Rosa canina). The resulting products were subjected to spectrophotometric analysis (UV-Vis), and testing of the nanoparticles' size and suspension stability was carried out by measuring the electrokinetic potential, ζ, via dynamic light scattering (DLS). Solid samples were imaged by scanning electron microscopy (SEM). The obtained data were given to statistical analysis in order to illustrate the properties of the suspension depending on the values of the input parameters: metal salts concentration, pH of the reaction mixture, and process temperature. In the course of the work, samples of nanosilver and nanogold were obtained, which were stable for over two months and which had a monomodal particle size distribution.
PMCID: PMC3912765  PMID: 24511306
20.  Preparation and Characterization of Di-, Tri-, and Tetranuclear Schiff Base Complexes Derived from Diamines and 3,4-Dihydroxybenzaldehyde 
A series of new di-, tri-, and tetranuclear Co(II) and Cu(II) complexes of three new diSchiff base ligands were synthesized by two different methods. The first method involved the synthesis of the three ligands from condensation reaction of 3,4-dihydroxybenzaldehyde (L′H2) with ethylenediamine (en), o-phenylenediamine (o-PD), or 4,5-dimethyl-1,2-phenylendiamine (DMPD) in a mole ratio of 2 : 1 followed by the reaction of the resulting Schiff bases ligands with Cu(II) or Co(II) ions in the presence of 2,2′-bipyridyl (L) to form the di- and trinuclear metal complexes. The second method involved the condensation of the copper complex LCu(II)L′ (L = 2,2′-bipyridyl, L′ = 4-formylbenzene-1,2-bis(olate)) with en, o-PD, or DMPD in a mole ratio of 2 : 1, respectively, followed by reaction with CuCl2 or Cu(ClO4)2 to form di-, tri-, and tetranuclear copper (II) complexes, respectively. The structures of the ligands and metal complexes were characterized by elemental analyses, NMR, and FTIR spectra. The geometries of metal complexes were suggested according to elemental analysis, electronic spectra, thermal analyses, atomic absorption, and magnetic moments and conductivity measurements.
PMCID: PMC3886601  PMID: 24453995
21.  Coordination Dynamics and Coordination Mechanism of a New Type of Anticoagulant Diethyl Citrate with Ca2+ Ions 
Diethyl citrate (Et2Cit) is a new potential anticoagulant. The coordination dynamics and coordination mechanism of Et2Cit with Ca2+ ions and the effect of pH on the complex were examined. The result was compared with that for the conventional anticoagulant sodium citrate (Na3Cit). The reaction order (n) of Et2Cit and Na3Cit with Ca2+ was 2.46 and 2.44, respectively. The reaction rate constant (k) was 120 and 289 L·mol−1·s−1. The reverse reaction rate constant (kre) was 0.52 and 0.15 L·mol−1·s−1, respectively. It is indicated that the coordination ability of Et2Cit with Ca2+ was weaker than that of Na3Cit. However, the dissociation rate of the calcium complex of Et2Cit was faster than that of Na3Cit. Increased pH accelerated the dissociation rate of the complex and improved its anticoagulant effect. The Et2Cit complex with calcium was synthesized and characterized by elemental analysis, XRD, FT-IR, 1H NMR, and ICP. These characteristics indicated that O in –COOH and C–O–C of Et2Cit was coordinated with Ca2+ in a bidentate manner with 1 : 1 coordination proportion; that is, complex CaEt2Cit was formed. Given that CaEt2Cit released Ca2+ more easily than Na3Cit, a calcium solution was not needed in intravenous infusions using Et2Cit as anticoagulant unlike using Na3Cit. Consequently, hypocalcemia and hypercalcemia were avoided.
PMCID: PMC3884681  PMID: 24453996
22.  Synthesis and Characterization of New Palladium(II) Thiosemicarbazone Complexes and Their Cytotoxic Activity against Various Human Tumor Cell Lines 
The palladium(II) bis-chelate complexes of the type [Pd(TSC1-5)2] (6–10), with their corresponding ligands 4-phenyl-1-(acetone)-thiosemicarbazone, HTSC1 (1), 4-phenyl-1-(2′-chloro-benzaldehyde)-thiosemicarbazone, HTSC2 (2), 4-phenyl-1-(3′-hydroxy-benzaldehyde)-thiosemicarbazone, HTSC3 (3), 4-phenyl-1-(2′-naphthaldehyde)-thiosemicarbazone, HTSC4 (4), and 4-phenyl-1-(1′-nitro-2′-naphthaldehyde)-thiosemicarbazone, HTSC5 (5), were synthesized and characterized by elemental analysis and spectroscopic techniques (IR and 1H- and 13C-NMR). The molecular structure of HTSC3, HTSC4, and [Pd(TSC1)2] (6) have been determined by single crystal X-ray crystallography. Complex 6 shows a square planar geometry with two deprotonated ligands coordinated to PdII through the azomethine nitrogen and thione sulfur atoms in a cis arrangement. The in vitro cytotoxic activity measurements indicate that the palladium(II) complexes (IC50 = 0.01–9.87 μM) exhibited higher antiproliferative activity than their free ligands (IC50 = 23.48–70.86 and >250 μM) against different types of human tumor cell lines. Among all the studied palladium(II) complexes, the [Pd(TSC3)2] (8) complex exhibited high antitumor activity on the DU145 prostate carcinoma and K562 chronic myelogenous leukemia cells, with low values of the inhibitory concentration (0.01 and 0.02 μM, resp.).
PMCID: PMC3874341  PMID: 24391528
23.  Stabilization of Submicron Calcium Oxalate Suspension by Chondroitin Sulfate C May Be an Efficient Protection from Stone Formation 
The influences of chondroitin sulfate C (C6S) on size, aggregation, sedimentation, and Zeta potential of sub-micron calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) crystallites with mean sizes of about 330 nm were investigated using an X-ray diffractometer, nanoparticle size Zeta potential analyzer, ultraviolet spectrophotometer, and scanning electron microscope, after which the results were compared with those of micron-grade crystals. C6S inhibited the conversion of COD to COM and the aggregation of COM and COD crystallitesis; it also decreased their sedimentation rate, thus increasing their stability in aqueous solution. The smaller the size of the COD crystallites, the easier they can be converted to COM. The stability of sub-micron COD was worse than that of micron-grade crystals. C6S can inhibit the formation of calcium oxalate stones.
PMCID: PMC3870629  PMID: 24382950
24.  Uptake and Distribution of Cd in Sweet Maize Grown on Contaminated Soils: A Field-Scale Study 
Maize is an economic crop that is also a candidate for use in phytoremediation in low-to-moderately Cd-contaminated soils, because the plant can accumulate high concentration of Cd in parts that are nonedible to humans while accumulating only a low concentration of Cd in the fruit. Maize cultivars CT38 and HZ were planted in field soils contaminated with Cd and nitrilotriacetic acid (NTA) was used to enhance the phytoextractive effect of the maize. Different organs of the plant were analyzed to identify the Cd sinks in the maize. A distinction was made between leaf sheath tissue and leaf lamina tissue. Cd concentrations decreased in the tissues in the following order: sheath > root > lamina > stem > fruit. The addition of NTA increased the amount of Cd absorbed but left the relative distribution of the metal among the plant organs essentially unchanged. The Cd in the fruit of maize was below the Chinese government's permitted concentration in coarse cereals. Therefore, this study shows that it is possible to conduct maize phytoremediation of Cd-contaminated soil while, at the same time, harvesting a crop, for subsequent consumption.
PMCID: PMC3856120  PMID: 24348276
25.  Concave Urinary Crystallines: Direct Evidence of Calcium Oxalate Crystals Dissolution by Citrate In Vivo 
The changes in urinary crystal properties in patients with calcium oxalate (CaOx) calculi after oral administration of potassium citrate (K3cit) were investigated via atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray powder diffractometry (XRD), and zeta potential analyzer. The AFM and SEM results showed that the surface of urinary crystals became concave, the edges and corners of crystals became blunt, the average size of urinary crystallines decreased significantly, and aggregation of urinary crystals was reduced. These changes were attributed to the significant increase in concentration of excreted citrate to 492 ± 118 mg/L after K3cit intake from 289 ± 83 mg/L before K3cit intake. After the amount of urinary citrate was increased, it complexed with Ca2+ ions on urinary crystals, which dissolved these crystals. Thus, the appearance of concave urinary crystals was a direct evidence of CaOx dissolution by citrate in vivo. The XRD results showed that the quantities and species of urinary crystals decreased after K3cit intake. The mechanism of inhibition of formation of CaOx stones by K3cit was possibly due to the complexation of Ca2+ with citrate, increase in urine pH, concentration of urinary inhibitor glycosaminoglycans (GAGs), and the absolute value of zeta potential after K3cit intake.
PMCID: PMC3855932  PMID: 24363634

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