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NMR Structure and CD Titration with Metal Cations of Human Prion α2-Helix-Related Peptides

The 173–195 segment corresponding to the helix 2 of the C-globular prion protein domain could be one of several “spots” of intrinsic conformational flexibility. In fact, it possesses chameleon conformational behaviour and gathers several disease-associated pointmutations.We have performed spectroscopic studies on the wild-type fragment 173–195 and on its D178Nmutant dissolved in trifluoroethanol to mimic the in vivo system, both in the presence and in the absence of metal cations. NMR data showed that the structure of the D178N mutant is characterized by two short helices separated by a kink, whereas the wild-type peptide is fully helical. Both peptides retained these structural organizations, as monitored by CD, in the presence of metal cations. NMR spectra were however not in favour of the formation of definite ion-peptide complexes. This agrees with previous evidence that other regions of the prion protein are likely the natural target of metal cation binding.
Автор: Luisa Ronga, Pasquale Palladino, Gabriella Saviano, Teodorico Tancredi, Ettore Benedetti, Raffaele Ragone, and Filomena Rossi 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1.33 Мб     Кількість завантажень: 41

Antispermatogenic Activity of the Benzothiazoline Ligand and Corresponding Organoantimony(V) Derivative in Male Albino Rats

Triphenylantimony(V) derivative, Ph3Sb(OPri)[SC6H4N : C(CH3)CH2C(O)CH3], 1b, and the corresponding benzothiazoline ligand [1, 2], HNC6H4SC(CH3)CH2C(O)CH3, 1a, have been tested for their effects on the reproductive system of male albino rats. The oral administration of both 1a and 1b at the dose level of 10 mg/rat/day produced significant reduction in the weights of testes, epididymides, seminal vesicles, and ventral prostate. Significant decrease in sperm motility as well as in sperm density resulted in 100% sterility. Significant (P < .01) alterations were also found in biochemical parameters of reproductive organs in treated male rats as compared to the control group. Production of preleptotene, pachytene, and secondary spermatocytes was decreased by 42%, 43%, 39%, and by 44%, 49%, 55% in the ligand, 1a, and organoantimony(V) derivative, 1b, treated rats, respectively. These results indicate that both compounds 1a and 1b are antispermatogenic in nature and on oral administration in male rats, and finally caused sterility. A comparison indicates that the organoantimony(V) derivative 1b is more effective pertaining to its antispermatogenic activity than the corresponding ligand 1a.
Автор: Pankaj K. Sharma, H. Rehwani, A. K. Rai, R. S. Gupta, and Y. P. Singh 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 507 Кб     Кількість завантажень: 41

Synthesis, Characterization, and Biotoxicity of N̑N Donor Sulphonamide Imine Silicon(IV) Complexes

The organosilicon derivatives of 2-[1-(2-furayl)ethyledene]sulphathiazole with organosilicon chlorides have been synthesised and characterized on the basis of analytical, conductance, and spectroscopic techniques. Probable trigonal bipyramidal and octahedral structures for the resulting derivatives have been proposed on the basis of electronic, IR, 1H, 13C NMR, and 29Si NMR spectral studies. In the search for better fungicides, bactericides, nematicides, and insecticides studies were conducted to assess the growth-inhibiting potential of the synthesized complexes against various pathogenic fungal, bacterial strains, root-knot nematode Meloidogyne incognita, and insect Trogoderma granarium. These studies demonstrate that the concentrations reached levels which are sufficient to inhibit and kill the pathogens, nematode, and insect.
Автор: Mukta Jain and R. V. Singh 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 544 Кб     Кількість завантажень: 41

Fertility Regulation inMale Rats by Implemented Tetraazamacrocyclic Compounds of Iron(II): Synthetic, Spectroscopic, and Applied Aspects With Toxicological Screening

Antifertility and histopathological investigations were carried out on reproductive organs of male albino rats induced by tetraazamacrocyclic complexes of iron(II). The complexes were synthesized by the template condensation of 1,2-diaminoethane, 1,3- diaminopropane with succinic acid and phthalic acid in 2 : 2 molar ratios which are abbreviated as [Fe(TAMLn)OAc] (n = 1 or 2 and TAMLn represents tetraazamacrocyclic ligand). The complexes have been characterized by elemental analysis, conductivity measurements, IR, and electronic spectra.
Автор: Ashu Chaudhary and Ran Vir Singh 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 555 Кб     Кількість завантажень: 41

The Nature of the Chemical Bond in Linear Three-Body Systems: From I3 – toMixed Chalcogen/Halogen and Trichalcogen Moieties

The 3 centre-4 electrons (3c-4e) and the donor/acceptor or charge-transfer models for the description of the chemical bond in linear three-body systems, such as I3 − and related electron-rich (22 shell electrons) systems, are comparatively discussed on the grounds of structural data from a search of the Cambridge Structural Database (CSD). Bothmodels account for a total bond order of 1 in these systems, and while the former fits better symmetric systems, the latter describes better strongly asymmetric situations. The 3c-4e MO scheme shows that any linear system formed by three aligned closed-shell species (24 shell electrons overall) has reason to exist provided that two electrons are removed from it to afford a 22 shell electrons three-body system: all combinations of three closed-shell halides and/or chalcogenides are considered here. A survey of the literature shows that most of these threebody systems exist. With some exceptions, their structural features vary continuously from the symmetric situation showing two equal bonds to very asymmetric situations in which one bond approaches to the value corresponding to a single bond and the second one to the sum of the van der Waals radii of the involved atoms. This indicates that the potential energy surface of these three-body systems is fairly flat, and that the chemical surrounding of the chalcogen/halogen atoms can play an important role in freezing different structural situations; this is well documented for the I3 − anion. The existence of correlations between the two bond distances and more importantly the linearity observed for all these systems, independently on the degree of their asymmetry, support the state of hypervalency of the central atom.
Автор: M. Carla Aragoni, Massimiliano Arca, Francesco A. Devillanova, Alessandra Garau, Francesco Isaia, Vito Lippolis, and Annalisa Mancini 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,87 Мб     Кількість завантажень: 41

Effect of Benzothiazoline Ligand and Corresponding Organoantimony(V) Derivative on the Reproductive System of Male Rats


Автор: D. Shanker, A. K. Rai, Y. P. Singh, H. Rehwani, V. Khushalani, and R. S. Gupta 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 1,13 Мб     Кількість завантажень: 41

Bioinorganic Chemistry in Thyroid Gland: Effect of Antithyroid Drugs on Peroxidase-Catalyzed Oxidation and Iodination Reactions

Propylthiouracil (PTU) and methimazole (MMI) are the most commonly used antithyroid drugs. The available data suggest that these drugs may block the thyroid hormone synthesis by inhibiting the thyroid peroxidase (TPO) or diverting oxidized iodides away from thyroglobulin. It is also known that PTU inhibits the selenocysteine-containing enzyme ID-1 by reacting with the selenenyl iodide intermediate (E-SeI). In view of the current interest in antithyroid drugs, we have recently carried out biomimetic studies to understand the mechanism by which the antithyroid drugs inhibit the thyroid hormone synthesis and found that the replacement of sulfur with selenium in MMI leads to an interesting compound that may reversibly block the thyroid hormone synthesis. Our recent results on the inhibition of lactoperoxidase (LPO)-catalyzed oxidation and iodination reactions by antithyroid drugs are described.
Автор: Gouriprasanna Roy and G. Mugesh 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 1,04 Мб     Кількість завантажень: 41

Synthetic, Structural, and Biochemical Studies of Organotin(IV)With Schiff Bases Having Nitrogen and Sulphur Donor Ligands

Three bidentate Schiff bases having nitrogen and sulphur donor sequences were prepared by condensing S-benzyldithiocarbazate (NH2NHCS2CH2C6H5) with heterocyclic aldehydes. The reaction of diphenyltin dichloride with Schiff bases leads to the formation of a new series of organotin(IV) complexes. An attempt has been made to prove their structures on the basis of elemental analyses, conductance measurements, molecular weights determinations, UV, infrared, and multinuclear magnetic resonance (1H, 13C, and 119Sn) spectral studies. Organotin(IV) complexes were five- and six-coordinate. Schiff bases and their corresponding organotin complexes have also been screened for their antibacterial and antifungal activities and found to be quite active in this respect.
Автор: Har Lal Singh and A. K. Varshney 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 509 Кб     Кількість завантажень: 41

New Perspectives on Thiamine Catalysis: From Enzymic to Biomimetic Catalysis

This paper is a brief review of the detailed mechanism of action of thiamine enzymes, based on metal complexes of bivalent transition and post-transition metals of model compounds, thiamine derivatives, synthesized and characterized with spectroscopic techniques and X-ray crystal structure determinations. It is proposed that the enzymatic reaction is initiated with a V conformation of thiamine pyrophosphate, imposed by the enzymic environment. Thiamine pyrophosphate is linked with the proteinic substrate through its pyrophosphate oxygens. In the course of the reaction, the formation of the “active aldehyde” intermediate imposes the S conformation to thiamine, while a bivalent metal ion may be linked through the N1’ site of the molecule, at this stage. Finally, the immobilization of thiamine and derivatives on silica has a dramatic effect on the decarboxylation of pyruvic acid, reducing the time of its conversion to acetaldehyde from 330 minutes for the homogeneous system to less than 5 minutes in the heterogenous system.
Автор: A. Stamatis, G.Malandrinos,M. Louloudi, and N. Hadjiliadis 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 586 Кб     Кількість завантажень: 41

Kinetic Study of DNA Modification by Phthalocyanine Derivative of the Oligonucleotide

Design of chemically modified oligonucleotides for regulation of gene expression has attracted considerable attention over the last decades. One actively pursued approach involves antisense or antigene constructs carrying reactive groups, many of these based on transition metal complexes. The complexes of Co(II) with phthalocyanines are extremely good catalysts of oxidation of organic compounds with molecular oxygen and hydrogen peroxide. In this study, we have investigated the kinetics and thermodynamics of sequence-specific modification of DNA with deoxyribooligonucleotide linked to Co(II)-tetracarboxyphthalocyanine (PtcCo(II)) in the presence of H2O2.
Автор: Alexandra A. Kuznetsova, Alexander A. Chernonosov, Nikita A. Kuznetsov, Vladimir V. Koval, Dmitri G. Knorre, and Olga S. Fedorova 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 1,07 Мб     Кількість завантажень: 41

Synthesis and Properties of N-Bromosuccinimide Derivatives of Ammonium Dialkyl/Alkylene Dithiophosphates

Reaction of N-bromosuccinimide with ammonium salt of alkylene (dialkyl) dithiophosphates, [OGOPS2NH4; G=–CMe2CMe2– CH2CMe2CH2–, CMe2CH2CHMe2–, CH2CH2CHMe2–; (RO)2PS2NH4; R=C2H5, n–C3H7, i–C3 H7], in 1 : 1 molor ratio in refluxing benzene solution yields red/brown-colored sticky liquids. These newly synthesized complexes have been characterised by physicochemical and spectroscopic techniques (MW, IR, NMR [1H and 31P]). The computational semiempirical calculations (MOPAC6P/c) have also been studied for these complexes. On the basis of the above studies, the formation of P–S–N chemical linkage has been established.
Автор: Neelam Harkut and Padam N. Nagar 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,49 Мб     Кількість завантажень: 41

Synthesis, Characterization, and Cytotoxic Activity of New Lanthanum(III) Complexes of Bis-Coumarins

Complexes of lanthanum(III) with bis-coumarins: 3,3_-benzylidene-bis(4-hydroxy-2H-1-benzopyran-2-one) (H2L1) and bis(4- hydroxy-2-oxo-2H-chromen-3-yl)-(1H-pyrazol-3-yl)-methane (H2L2) were synthesized by reaction of lanthanum(III) salt and the ligands, in amounts equal to metal : ligand molar ratio of 1 : 2. The complexes were prepared by adding an aqueous solution of lanthanum(III) salt to an aqueous solution of the ligand subsequently raising the pH of the mixture gradually to circa 5.0 by adding dilute solution of sodium hydroxide. The lanthanum(III) complexes with bis-coumarins were characterized by different physicochemical methods—elemental analysis, IR-, 1H-, and 13C-NMR-spectroscopies, and mass spectral data. The spectral data of lanthanum(III) complexes were interpreted on the basis of comparison with the spectra of the free ligands. This analysis showed that in the La(III) complexes, the ligands coordinated to the metal ion through both deprotonated hydroxyl groups. On the basis of the ν(C=O) red shift observed, participation of the carbonyl groups in the coordination with the metal ion was also suggested. In the present study, we performed a cytotoxic-effects screening of the lanthanum complexes with H2L1 and H2L2 in a panel of human tumor cell lines, using the standard MTT-dye reduction assay for cell viability. The panel consisted of the acute myeloid leukemia-derived HL-60 and the chronic myeloid leukemia-derived BV-173. Following a 24- hour treatment of BV-173 cells with lanthanum complex of H2L1 at 100 or 200 μM led to a DNA-laddering. The findings suggest that the observed cytotoxicity of the lanthanum complex of H2L1 on BV-173 is at least partly mediated through induction of programmed cell death.
Автор: Irena Kostova, Georgi Momekov, Tzvetomira Tzanova, and Margarita Karaivanova 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 691 Кб     Кількість завантажень: 41

AMononuclear and aMixed-Valence Chain Polymer Arising from Copper(II) Halide Chemistry and the Use of 2,2’-Pyridil


Автор: Constantinos J.Milios, Catherine P. Raptopoulou, Aris Terzis, Spyros P. Perlepes, and Giannis S. Papaefstathiou 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 983 Кб     Кількість завантажень: 41

Thermodynamic and Structural Characterization of the Copper(II) Complexes of Peptides Containing Both Histidyl and Aspartyl Residues

Terminally protected pentapeptides with 2 histidines (Ac-HHVGD-NH2 and Ac-HVGDH-NH2) and the terminally free peptides containing both internal aspartyl and C-terminal histidyl residues (FDAH and VIDAH) have been synthesized, and copper(II) complexes studied by potentiometric, UV-Vis, CD, and EPR spectroscopic techniques in solution. Both thermodynamic and spectroscopic data reveal that side chain donor atoms of aspartyl and histidyl residues have a significant contribution to the metal binding affinity of peptide molecules. In the case of terminally protected peptides, the role of the imidazole-N donor functions is reflected in the enhanced stability of the 3N and 4N coordinated copper(II) complexes. The amino and β-carboxylate groups of FDAH and VIDAH create a very effective metal binding site with the (NH2, N−, β-COO−) and (NH2, N−, N−, β-COO−) coordination modes including the N-termini, while the histidine sites are available for the formation of the (Nim, N−, N−) binding mode resulting in the preference of dinuclear complex formation.
Автор: Csilla K´allay, Zoltan Nagy, Katalin Varnagy, Gerasimos Malandrinos, Nick Hadjiliadis, and Imre Sovago 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 911 Кб     Кількість завантажень: 41

New Dihydro OO’Bis(Salicylidene) 2,2’ Aminobenzothiazolyl Borate Complexes: Kinetic and Voltammetric Studies of Dimethyltin Copper Complex with Guanine, Adenine, and Calf Thymus DNA


Автор: Farukh Arjmand, Bhawana Mohani, and Shamima Parveen 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 822 Кб     Кількість завантажень: 41

Co(III) and Ni(II) Complexes Containing Bioactive Ligands: Synthesis, DNA Binding, and Photocleavage Studies


Автор: M. C. Prabhakara, B. Basavaraju and H. S. BhojyaNaik 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,04 Мб     Кількість завантажень: 41

Transition Metal Complexes of Quinolino[3,2-b]benzodiazepine and Quinolino[3,2-b]benzoxazepine: Synthesis, Characterization, and Antimicrobial Studies


Автор: B. Basavaraju, Halehatty S. Bhojya Naik and Mustur C. Prabhakara 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 514 Кб     Кількість завантажень: 41

Characterization of Cu(II)-ACC Complexes and Conversion of the Bound ACC into Ethylene in the Presence of Hydrogen Peroxide. Detection of a Brown Intermediate at Low Temperature


Автор: Wadih Ghattas, Michel Giorgi, Christian Gaudin, Antal Rockenbauer, Marius R´eglier, and A. Jalila Simaan 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 810 Кб     Кількість завантажень: 41

Theoretical Investigation of Halogen-Oxygen Bonding and Its Implications in Halogen Chemistry and Reactivity


Автор: Agnie Mylona Kosmas 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 623 Кб     Кількість завантажень: 41

Synthesis, Spectroscopic, and Antimicrobial Studies on Bivalent Nickel and Copper Complexes of Bis(thiosemicrbazone)


Автор: Sulekh Chandra, Smriti Raizada, Monika Tyagi and Archana Gautam 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 579 Кб     Кількість завантажень: 41

Synthesis, X-Ray Structure, and Characterization of a Complex Containing the Hexakis(urea)cobalt(II) Cation and Lattice Urea Molecules


Автор: Labrini Drakopoulou, Constantina Papatriantafyllopoulou, Aris Terzis, Spyros P. Perlepes, Evy Manessi-Zoupa, and Giannis S. Papaefstathiou 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,62 Мб     Кількість завантажень: 41

Characterization of Copper(II) Interactions with Sinefungin, a Nucleoside Antibiotic: Combined Potentiometric, Spectroscopic and DFT Studies


Автор: Maria Jaworska, Piotr Lodowski, ArielMucha, Wojciech Szczepanik, Gianni Valensin, Massimo Cappannelli, and Małgorzata Je˙zowska-Bojczuk 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 2,92 Мб     Кількість завантажень: 41

Folding and Unfolding in the Blue Copper Protein Rusticyanin: Role of the Oxidation State


Автор: Luis A. Alcaraz, Javier G´omez, Pablo Ram´ırez, Juan J. Calvente, Rafael Andreu, and Antonio Donaire 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 2,39 Мб     Кількість завантажень: 41

DNA Binding and Photocleavage Studies of Cobalt(III) Polypyridine Complexes: [Co(en)2PIP]3+, [Co(en)2IP]3+, and [Co(en)2phen-dione]3+


Автор: Penumaka Nagababu and S. Satyanarayana 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,29 Мб     Кількість завантажень: 41

Platinum(II) and Palladium(II) Complexes of Pyridine-2-Carbaldehyde Thiosemicarbazone as Alternative Antiherpes Simplex Virus Agents


Автор: D. Kovala-Demertzi, T. Varadinova, P. Genova, P. Souza, and M. A. Demertzis 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 565 Кб     Кількість завантажень: 41

Reactions Between Chalcogen Donors and Dihalogens/Interalogens: Typology of Products and Their Characterization by FT-Raman Spectroscopy

The chemical bond and structural features for the most important classes of solid products obtained by reacting chalcogen donors with dihalogens and interhalogens are reviewed. Particular attention is paid to the information the FT-Raman spectroscopy can confidently give about each structural motif considered in the absence of X-ray structural analyses.
Автор: Massimiliano Arca,M. Carla Aragoni, Francesco A. Devillanova, Alessandra Garau, Francesco Isaia, Vito Lippolis, AnnalisaMancini, and Gaetano Verani 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 871 Кб     Кількість завантажень: 41

Synthesis, Spectral, and Biological Properties of Copper(II) Complexes of Thiosemicarbazones of Schiff Bases Derived from 4-Aminoantipyrine and Aromatic Aldehydes


Автор: RamK. Agarwal, Lakshman Singh, and Deepak Kumar Sharma 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 565 Кб     Кількість завантажень: 41

Assessment of Toxicity of Some Penta- and Hexacoordinated Organotin(IV) and Tetracoordinated Tin(II) Complexes of Heterocyclic β-Diketones


Автор: Asha Jain, Sanjiv Saxena, Audhesh K. Rai, and Prabhu N. Saxena 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 465 Кб     Кількість завантажень: 41

Interaction of Thioamides, Selenoamides, and AmidesWith Diiodine


Автор: Sotiris K. Hadjikakou and Nick Hadjiliadis 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 1,08 Мб     Кількість завантажень: 41

Conjugates of PhthalocyaninesWith Oligonucleotides as Reagents for Sensitized or Catalytic DNA Modification


Автор: Alexander A. Chernonosov, Vladimir V. Koval, Dmitrii G. Knorre,, Alexander A. Chernenko, ValentinaM. Derkacheva, Eugenii A. Lukyanets, and Olga S. Fedorova 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 578 Кб     Кількість завантажень: 41

Protective Effect of Meso-Tetrakis-(3,5-di-tert-butyl- 4-hydroxyphenyl)porphyrin on the In Vivo Impact of Trimethyltin Chloride on the Antioxidative Defense System


Автор: Elena R.Milaeva, Vladimir Yu. Tyurin, Yulia A. Gracheva, Margarita A. Dodochova, Lydia M. Pustovalova, and Victor N. Chernyshev 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 745 Кб     Кількість завантажень: 41

Lower-RimSubstituted Calixarenes and Their Applications

This review discusses in detail “calixarenes” since their discovery as by-products of the phenol formaldehyde bakelites till the present scenario wherein calixarene has assumed a new dimension in the field of supramolecular chemistry. Extensive literature exists for calixarenes; but herein we have tried to concentrate on the different lower-rim modified calixarenes with their potential applications. An attempt has also been made to critically evaluate the synthesis procedures for different lower-rim substituted calixarenes.
Автор: Princy Jose and Shobana Menon 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,36 Мб     Кількість завантажень: 41

Structure-Activity Relationships of Synthetic Coumarins as HIV-1 Inhibitors


Автор: I. Kostova, S. Raleva, P. Genova, and R. Argirova 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 541 Кб     Кількість завантажень: 41

Spectroscopic, Thermal and Biological Studies on Some Trivalent Ruthenium and Rhodium NS Chelating Thiosemicarbazone Complexes


Автор: Vinod K. Sharma, Shipra Srivastava, and Ankita Srivastava 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 557 Кб     Кількість завантажень: 41

Pressure-Tuning Raman Spectra of Diiodine Thioamide Compounds:Models for Antithyroid Drug Activity


Автор: Ghada J. Corban, Constantinos Antoniadis, Sotiris K. Hadjikakou, Nick Hadjiliadis, Jin-Fang Meng, and Ian S. Butler 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 666 Кб     Кількість завантажень: 41

Regioselective Synthesis of Bis(2-halo-3-pyridyl) Dichalcogenides (E = S, Se and Te): Directed Ortho-Lithiation of 2-halopyridines

A novel method for the preparation of hitherto unknown symmetrical bis(2-halo-3-pyridyl) dichalcogenides (E = S, Se and Te) by the oxidation of intermediate 2-halo-3-pyridyl chalcogenolate, prepared by lithiation of 2-halo pyridines using lithium diisopropylamine is being reported. All the newly synthesized compounds have been characterized through elemental analysis employing various spectroscopic techniques, namely, NMR (1H, 13C, 77Se), infrared, mass spectrometry, and X-ray crystal structures in representative cases.
Автор: K. K. Bhasin, Neelam Singh, Shivani Doomra, Ekta Arora, Ganga Ram, Sukhjinder Singh, Yogesh Nagpal, S. K. Mehta, and T.M. Klapotke 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,54 Мб     Кількість завантажень: 41

Antihuman Immunodeficiency Virus Type 1 (HIV-1) Activity of Rare Earth Metal Complexes of 4-Hydroxycoumarins in Cell Culture


Автор: Ilia Manolov, Sevda Raleva, Petya Genova, Alexey Savov, Liliana Froloshka, Daniela Dundarova and Radka Argirova 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 601 Кб     Кількість завантажень: 41

Lanthanide(III) and Yttrium(III) Complexes of Benzimidazole-2-Acetic Acid: Synthesis, Characterisation and Effect of La(III) Complex on Germination ofWheat

The synthesis and characterisation of lanthanide(III) and yttrium(III) nitrate complexes of benzimidazole-2-acetic acid (HBIA) are reported. The complexes have been characterised by elemental analysis, molar conductance, magnetic studies, IR, 1H NMR, UV-visible, EPR, and TG/DTA studies. They have the stoichiometry [Ln3(BIA)2(NO3)7(H2O)4] · 3H2O where Ln=La(III), Pr(III), Nd(II), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), and Y(III). The effect of La(III) complex on germination, coleoptile, and root length of two local varieties of wheat DWR-195 and GW-349 for different treatment periods has been investigated. The complex was found to exhibit enhanced activity, compared to HBIA or metal salt alone at lower treatment periods.
Автор: Kalagouda B. Gudasi, Rashmi V. Shenoy, Ramesh S. Vadavi, Manjula S. Patil, Siddappa A. Patil, Rayappa R. Hanchinal, Srinivas A. Desai, and H. Lohithaswa 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 684 Кб     Кількість завантажень: 41

Proposal for Sets of 77Se NMR Chemical Shifts in Planar and Perpendicular Orientations of Aryl Group and the Applications


Автор: Satoko Hayashi and Waro Nakanishi 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 914 Кб     Кількість завантажень: 41

Synthesis, Superoxide DismutaseMimetic and Anticancer Activities of Metal Complexes of 2,2-Dimethylpentanedioic Acid(2dmepdaH2) and 3,3-Dimethylpentanedioic acid(3dmepdaH2): X-Ray Crystal Structures of [Cu(3dmepda)(bipy)]2 · 6H2Oand [Cu(2dmepda)(bipy)(EtOH)]2 · 4EtOH (bipy = 2,2


Автор: Michael Devereux, Malachy McCann, Denis O’Shea, Mark O’Connor, Eileen Kiely, Vickie McKee, Declan Naughton, Anna Fisher, Andrew Kellett, MaureenWalsh, Denise Egan, and Carol Deegan 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 724 Кб     Кількість завантажень: 41

Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II), Cu(II), Ni(II), and Zn(II) Complexes With Amino Acid-Derived Compounds


Автор: Zahid H. Chohan, M. Arif, Muhammad A. Akhtar, and Claudiu T. Supuran 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 633 Кб     Кількість завантажень: 41

Synthesis, Spectroscopic, and Antimicrobial Studies of Binuclear Metallocene (M = Ti, Zr, or Hf) Derivatives of Bis(mercaptoazoles)


Автор: Shilpi Sinha, Akhilesh Kumar Srivastava, Chandra Mohan Tripathi, Om Prakash Pandey, and Soumitra Kumar Sengupta 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 550 Кб     Кількість завантажень: 41

DNA-Metallodrugs Interactions Signaled by Electrochemical Biosensors: An Overview

The interaction of drugs with DNA is an important aspect in pharmacology. In recent years, many important technological advances have been made to develop new techniques to monitor biorecognition and biointeraction on solid devices. The interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. The propensity of a given compound to interact with DNA is measured as a function of the decrease of guanine oxidation signal on a DNA electrochemical biosensor. Covalent binding at N7 of guanine, electrostatic interactions, and intercalation are the events that this kind of biosensor can detect. In this context, the interaction between a panel of antitumoral Pt-, Ru-, and Ti-based metallodrugs with DNA immobilized on screen-printed electrodes has been studied. The DNA biosensors are used for semiquantitative evaluation of the analogous interaction occurring in the biological environment.
Автор: Mauro Ravera, Graziana Bagni, Marco Mascini, and Domenico Osella 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 811 Кб     Кількість завантажень: 41

Organosilicon-Containing Thiazole Derivatives as Potential Lipoxygenase Inhibitors and Anti-Inflammatory Agents


Автор: Athina Geronikaki, Dimitra Hadjipavlou-Litina, Alla Zablotskaya, and Izolda Segal 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 527 Кб     Кількість завантажень: 41

Chemical Analysis through CL-Detection Assisted by Periodate Oxidation

The progress of the research work of the author and his colleagues on the field of CL-emission generated by pyrogallol oxidation and further application for the direct determination of periodate and indirect or direct determination of other compounds through flow-injection manifold/CL-detection set up is described. The instrumentation used for these studies was a simple flowinjection manifold that provides good reproducibility, coupled to a red sensitive photomultiplier that gives sensitive CL-detection. In addition, recent reports on studies and analytical methods based on CL-emission generated by periodate oxidation by other authors are included.
Автор: Nicholaos P. Evmiridis, Athanasios G. Vlessidis, and Nicholas C. Thanasoulias 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,11 Мб     Кількість завантажень: 41

Interaction of Imidazole Containing Hydroxamic Acids with Fe(III): Hydroxamate Versus Imidazole Coordination of the Ligands


Автор: Etelka Farkas, D´avid B´atka, Hajnalka Csoka, and N´ora V. Nagy 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 847 Кб     Кількість завантажень: 41

Design and Synthesis of Redox-Switched Lariat Ethers and Their Application for Transport of Alkali and Alkaline-Earth Metal Cations Across Supported LiquidMembrane


Автор: Anubhuti Awasthy,Mamta Bhatnagar, Jyoti Tomar, and Uma Sharma 
Рік видання: 2006. Тип документу: Складова частина документу 
Розмір: 484 Кб     Кількість завантажень: 41

Complexes of Pd(II) and Pt(II) with 9-Aminoacridine: Reactions with DNA and Study of Their Antiproliferative Activity


Автор: X. Riera, V. Moreno, C. J. Ciudad, V. Noe, M. Font-Bard´ıa, and X. Solans 
Рік видання: 2007. Тип документу: Складова частина документу 
Розмір: 1,65 Мб     Кількість завантажень: 41

Phosphinegold(I) Thiolates Pharmacological Use and Potential

A brief overview of the use of gold compounds in medicine, namely in the treatment of rheumatoid arthritis is presented, including that of the orally-administered triethylphosphinegold(I) tetraacetylatedthioglucose species, auranofin. A summary of an evaluation for anti-arthritic activity of novel phosphinegold(I) thiolate analogues containing biologically active thiols is given. This shows that compounds with greater efficacy and reduced toxic side-effects, at least in the in vivo model studied, can be developed. More recent investigations on this class of compound have focussed on their putative anti-tumour activity. Significant cytotoxicity and apparent cellular specificity have been discovered for certain phosphinegold(I) thiolates carrying water-solubilising groups. All indications are there that the continued exploration of the medicinal properties of phosphinegold(I) thiolates offers very real opportunities in metallotherapeutics.
Автор: Edward R.T. Tiekink 
Рік видання: 2003. Тип документу: Складова частина документу 
Розмір: 1,96 Мб     Кількість завантажень: 41

“Lantern-Shaped” Platinum(III) Complexes with Axially Bound 9-Ethylguanine or 1-Methylcytosine (L) of General Formula [Pt2{HN=C(But)O}4L2](NO3)2


Автор: Concetta Pacifico, Francesco Paolo Intini, Fiorentin Nushi, and Giovanni Natile 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 878 Кб     Кількість завантажень: 41

Synthesis and Supramolecular Structure of a (5-(3-(1H-tetrazol-5-yl)phenyl)-1H-tetrazole) Cobalt Complex

The reaction of CoCl2·6H2O with m-BDTH2 (1,3-benzeneditetrazol-5-yl) leads to [Co(C8H6N8)2(H2O)2(CH3CN)2]Cl2 (1). Both tetrazolic groups remain protonated existing in a 1H tautomeric form. A trifurcated chlorine atom and stacking interactions assemble compound 1 into a three-dimensional network.
Автор: George E. Kostakis, Christopher E. Anson, and Annie K. Powell 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,45 Мб     Кількість завантажень: 41

Synthesis and Characterization of the Ligand Based on Benzimidazole and Its Copper Complex: DNA Binding and Antioxidant Activity


Автор: HuiluWu, Fan Kou, Fei Jia, Bin Liu, Jingkun Yuan, and Ying Bai 
Рік видання: 2011. Тип документу: Складова частина документу 
Розмір: 1,35 Мб     Кількість завантажень: 41

Electrospun Nanostructured Fibers of Collagen-Biomimetic Apatite on Titanium Alloy

Titanium and its alloys are currently the mainly used materials to manufacture orthopaedic implants due to their excellent mechanical properties and corrosion resistance. Although these materials are bioinert, the improvement of biological properties (e.g., bone implant contact) can be obtained by the application of a material that mimics the bone extracellular matrix. To this aim, this work describes a new method to produce nanostructured collagen-apatite composites on titanium alloy substrate, by combining electrospinning and biomimetic mineralization. The characterization results showed that the obtained mineralized scaffolds have morphological, structural, and chemical compositional features similar to natural bone extracellular matrix. Finally, the topographic distribution of the chemical composition in the mineralized matrix evaluated by Fourier Transform Infrared microspectroscopy demonstrated that the apatite nanocrystals cover the collagen fibers assembled by the electrospinning.
Автор: Michele Iafisco, Ismaela Foltran, Simona Sabbatini, Giorgio Tosi, and Norberto Roveri 
Рік видання: 2012. Тип документу: Складова частина документу 
Розмір: 3,38 Мб     Кількість завантажень: 41

pH-Potentiometric Investigation towards Chelating Tendencies of p-Hydroquinone and Phenol Iminodiacetate Copper(II) Complexes

Copper ions in the active sites of several proteins/enzymes interact with phenols and quinones, and this interaction is associated to the reactivity of the enzymes. In this study the speciation of the Cu2+ with iminodiacetic phenolate/hydroquinonate ligands has been examined by pH-potentiometry. The results reveal that the iminodiacetic phenol ligand forms mononuclear complexes with Cu2+ at acidic and alkaline pHs, and a binuclear Ophenolate-bridged complex at pH range from 7 to 8.5. The binucleating hydroquinone ligand forms only 2 : 1 metal to ligand complexes in solution. The pK values of the protonation of the phenolate oxygen of the two ligands are reduced about 2 units after complexation with the metal ion and are close to the pK values for the copper-interacting tyrosine phenol oxygen in copper enzymes.
Автор: Marios Stylianou, Anastasios D. Keramidas, and Chryssoula Drouza 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 755 Мб     Кількість завантажень: 41

Special Issue in Honor of Professor Nick Hadjiliadis’ Retirement


Автор: EvyManessi-Zoupa and Spyros P. Perlepes 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 426 Мб     Кількість завантажень: 41

Antineoplastic Activity of New TransitionMetal Complexes of 6-Methylpyridine-2-carbaldehyde-N(4)-ethylthiosemicarbazone: X-Ray Crystal Structures of [VO2(mpETSC)] and [Pt(mpETSC)Cl]

New complexes of dioxovanadium(V), zinc(II), ruthenium(II), palladium(II), and platinum(II) with 6-methylpyridine-2- carbaldehyde-N(4)-ethylthiosemicarbazone (HmpETSC) have been synthesized. The composition of these complexes is discussed on the basis of elemental analyses, IR, Raman, NMR (1H, 13C, and 31P), and electronic spectral data. The X-ray crystal structures of [VO2(mpETSC)] and [Pt(mpETSC)Cl] are also reported. The HmpETSC and its [Zn(HmpETSC)Cl2] and [Pd(mpETSC)Cl] complexes exhibit antineoplastic activity against colon cancer human cell lines (HCT 116).
Автор: Shadia A. Elsayed, Ahmed M. El-Hendawy, Sahar I.Mostafa, Bertrand J. Jean-Claude, Margarita Todorova, and Ian S. Butler 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,12 Мб     Кількість завантажень: 41

Interaction of Cu(II)with His-Val-Gly-Asp and of Zn(II) with His-Val-His, Two Peptides at the Active Site of Cu,Zn-Superoxide Dismutase


Автор: Alexandra Myari, Gerasimos Malandrinos, John Plakatouras, Nick Hadjiliadis and Imre Sovago 
Рік видання: 2003. Тип документу: Складова частина документу 
Розмір: 1,31 Мб     Кількість завантажень: 41

Synthesis, Spectroscopic and Toxicity Studies of Titanocene Chelates of Isatin-3- Thiosemicarbazones

The reactions of bis(cyclopentadienyl)titanium(IV) dichloride with a new class of thiosemicarbazone (LH2), derived by condensing isatin with different N(4)-substituted thiosemicarbazides, have been studied and products of type [Cp2Ti(L)] have been isolated. On the basis of various physico-chemical and spectral studies, five coordinate structures have been assigned to these derivatives. Toxicity studies of titanocene complexes at tbur different concentrations have been carried out against snail Lymnaea acuminata. The effect of most potent compounds on the activity of acetylcholinesterase enzyme, which inhibits the activity of enzyme, possibly by the formation of enzyme-inhibitor complex, was also studied.
Автор: Garima Vatsa, O. P. Pandey and S. K. Sengupta 
Рік видання: 2005. Тип документу: Складова частина документу 
Розмір: 1,07 Мб     Кількість завантажень: 41

Use of the 2-Pyridinealdoxime/N,N-Donor Ligand Combination in Cobalt(III) Chemistry: Synthesis and Characterization of Two CationicMononuclear Cobalt(III) Complexes


Автор: Konstantis F. Konidaris, Catherine P. Raptopoulou, Vassilis Psycharis, Spyros P. Perlepes, Evy Manessi-Zoupa, and Theocharis C. Stamatatos 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,31 Мб     Кількість завантажень: 41

Antioxidative Activity of Ferrocenes Bearing 2,6-Di-Tert -ButylphenolMoieties


Автор: E. R.Milaeva, S. I. Filimonova, N. N.Meleshonkova, L. G. Dubova, E. F. Shevtsova, S. O. Bachurin, and N. S. Zefirov 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 661 Кб     Кількість завантажень: 41

Synthesis, Structure, and Antiproliferative Activity of Three Gallium(III) Azole Complexes

As part of our interest into the bioinorganic chemistry of gallium, gallium(III) complexes of the azole ligands 2,1,3- benzothiadiazole (btd), 1,2,3-benzotriazole (btaH), and 1-methyl-4,5-diphenylimidazole (L) have been isolated. Reaction of btaH or btd with GaBr3 or GaCl3 resulted in the mononuclear complexes [GaBr3(btaH)2] (1) and [GaCl3(btd)2] (2), respectively, while treatment of GaCl3 with L resulted in the anionic complex (LH)2[GaCl4] (3). All three complexes were characterized by singlecrystal X-ray crystallography and IR spectroscopy, while their antiproliferative activities were investigated against a series of human and mouse cancer cell lines.
Автор: Stergios Zanias, Giannis S. Papaefstathiou, Catherine P. Raptopoulou, Konstantinos T. Papazisis, Vasiliki Vala, Dimitra Zambouli, Alexandros H. Kortsaris, Dimitrios A. Kyriakidis, and Theodoros F. Zafiropoulos 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 2,34 Мб     Кількість завантажень: 41

Molecular Architectures Derived fromMetal Ions and the Flexible 3,3-Bipyridine Ligand: Unexpected Dimer with Hg(II)


Автор: Anupam Khutia, Pablo J. Sanz Miguel, and Bernhard Lippert 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 2,42 Мб     Кількість завантажень: 41

DynamicMechanical Response of Biomedical 316L Stainless Steel as Function of Strain Rate and Temperature


Автор: Woei-Shyan Lee, Tao-Hsing Chen, Chi-Feng Lin, and Wen-Zhen Luo 
Рік видання: 2011. Тип документу: Складова частина документу 
Розмір: 3,30 Мб     Кількість завантажень: 41

Behavior and Distribution of Heavy Metals Including Rare Earth Elements, Thorium, and Uranium in Sludge from Industry Water Treatment Plant and Recovery Method of Metals by Biosurfactants Application

In order to investigate the behavior, distribution, and characteristics of heavymetals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavymetals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid) elution by batch and column experiments to evaluate the efficiency of biosurfactant for the removal of heavy metals. Consequently, the following matters have been largely clarified. (1) Heavy metallic elements in sludge have generally larger concentrations and exist as more unstable fraction than those in natural soil. (2) Nonionic saponin including carboxyl group is more efficient than sophorolipid for the removal of heavy metals in polluted sludge. Saponin has selectivity for the mobilization of heavy metals and mainly reacts with heavy metals in F3 (the fraction bound to carbonates) and F5 (the fraction bound to Fe-Mn oxides). (3) The recovery efficiency of heavy metals (Pb, Ni, and Cr) reached about 90–100% using a precipitation method with alkaline solution.
Автор: Lidi Gao, Naoki Kano, Yuichi Sato, Chong Li, Shuang Zhang, and Hiroshi Imaizumi 
Рік видання: 2012. Тип документу: Складова частина документу 
Розмір: 2,03 Мб     Кількість завантажень: 41

Zinc(II) and Nickel(II) Benzoate Complexes fromthe Use of 1-methyl-4,5-diphenylimidazole


Автор: Konstantina A. Kounavi, Manolis J.Manos, Anastasios J. Tasiopoulos, Spyros P. Perlepes, and Vassilios Nastopoulos 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,84 Мб     Кількість завантажень: 41

B3LYP Study on ReductionMechanisms fromO2 to H2Oat the Catalytic Sites of Fully Reduced andMixed-Valence Bovine Cytochrome c Oxidases


Автор: Yasunori Yoshioka and Masaki Mitani 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 3,13 Мб     Кількість завантажень: 41

Synthesis and Characterization of Novel Ruthenium(III) Complexes with Histamine

Novel ruthenium(III) complexes with histamine [RuCl4(dmso-S)(histamineH)]·H2O (1a) and [RuCl4(dmso-S)(histamineH)] (1b) have been prepared and characterized by X-ray structure analysis. Their crystal structures are similar and show a protonated amino group on the side chain of the ligand which is not very common for a simple heterocyclic derivative such as histamine. Biological assays to test the cytotoxicity of the compound 1b combined with electroporation were performed to determine its potential for future medical applications in cancer treatment.
Автор: Jakob Kljun, Sasa Petricek, Dusan Zigon, Rosana Hudej, Damijan Miklavcic, and Iztok Turel 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 2,36 Мб     Кількість завантажень: 41

The Bioactivated Interfacial Behavior of the Fluoridated Hydroxyapatite-Coated Mg-Zn Alloy in Cell Culture Environments

A partially fluorine substituted hydroxyapatite- (FHA-) coated Mg-Zn alloy was prepared to investigate the interfacial behavior of degradable Mg-based biomaterials with degradable bioactive coatings in a cell culture environment. Peaks from the results of X-ray diffraction (XRD) were characterized and compared before and after cell culture. It was found that Ca-P, including poorly crystalline ion-substituted Ca-deficient HA (CDHA), was formed in greater amounts on the interface of coated samples compared with the uncoated ones. A thermodynamic mechanism for Ca-P formation on biodegradable Mg alloys in a cell culture environment is proposed. Combined with improved cell calcification, the-FHA coated Mg alloys have the ability to promote CDHA formation, as expected thermodynamically. It is suggested that the specific cell culture environment and the bone-like FHA coatings together facilitate the observed behavior.Moreover, cell culture environment probably increased the biomineralization to a detectable level by affecting the kinetics of apatite formation.
Автор: Jianan Li, Lei Cao, Yang Song, Shaoxiang Zhang, Changli Zhao, Fan Zhang, and Xiaonong Zhang 
Рік видання: 2011. Тип документу: Складова частина документу 
Розмір: 1,61 Мб     Кількість завантажень: 41

The Effect of Stereochemistry on Sodium Ion Complexation in Nucleoside-Metallacarborane Conjugates

Conjugates of purine and pyrimidine nucleosides: thymidine and 2-deoxyguanosine with cobalt-metallacarborane were studied for their sodium ion complexing properties. Formation of stable complexes of 1 : 1 stoichiometry was proved by ESI MS spectroscopy and 23Na NMR. Equilibrium constants and energies of complex formation were calculated. Complexation of alkalimetals by nucleoside-metallacarborane conjugates may affect the physicochemical and biological properties of the conjugates and should be taken into consideration during biological evaluation of these types of modifications.
Автор: Agnieszka B. Olejniczak, JanMilecki, and Grzegorz Schroeder 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,01 Мб     Кількість завантажень: 41

Comparative Analysis of Metal Binding Characteristics of Copper Chaperone Proteins, Atxl and ATOX1

The metal binding properties of the human copper chaperone ATOXI and its yeast homologue Atxl have been characterized. Complexes of these proteins with Cu(I), Ag (1), Cd(II) and Hg(II) were studied by native gel electrophoresis, chemical cross-linking followed by SDS-PAGE, as well as by size exclusion chromatography, mutagenesis and UV-visible absorption spectroscopy. Results indicate that binding of different metals to either ATOXI or Atxl altered conformation of subunit structure and the oligomerization state of the proteins. Furthermore, it has been demonstrated that freshly reduced apoprotein is capable to convert Cu(ll) to Cu(l) stoichiometrically to the amount of protein present, while oxidized protein is only twenty per cent as active. Titration of Cu(ll) with either oxidized or reduced protein resulted in similar increase in absorbance at 254 nm, implicating Cu-thiolate formation in both forms of the protein, but titration with Ag(i) caused the increase in absorbance at 254 nm with the reduced protein only. These data indicate that Cu(1), Ag(1), Hg(ll) and Cd(ll) are all capable of binding to ATOXI and Atxl, but the characteristics of the binding to these copper chaperones differ for different metals.
Автор: Suree Narindrasorasak, Xuefeng Zhang, Eve A. Roberts, and Bibudhendra Sarkar 
Рік видання: 2004. Тип документу: Складова частина документу 
Розмір: 2,99 Мб     Кількість завантажень: 41

Impact of Vanadium Complexes Treatment on the Oxidative Stress Factors inWistar Rats Plasma


Автор: R. Francik, M. Kro´sniak, M. Barlik, A. Kudła, R. Grybos, and T. Librowski 
Рік видання: 2011. Тип документу: Складова частина документу 
Розмір: 1,28 Мб     Кількість завантажень: 41

A Comparative Interaction between Copper Ions with Alzheimer’s β Amyloid Peptide and Human SerumAlbumin


Автор: G. Rezaei Behbehani, L. Barzegar, M.Mohebbian, and A. A. Saboury 
Рік видання: 2012. Тип документу: Складова частина документу 
Розмір: 526 Кб     Кількість завантажень: 41

Pharmacokinetic Study of Di-Phenyl-Di-(2,4-Difluobenzohydroxamato)Tin(IV): Novel Metal-Based Complex with Promising Antitumor Potential


Автор: Yunlan Li, Zhuyan Gao, Pu Guo, and Qingshan Li 
Рік видання: 2012. Тип документу: Складова частина документу 
Розмір: 1,24 Мб     Кількість завантажень: 41

Reaction of Chromium(III) with 3,4-Dihydroxybenzoic Acid: Kinetics and Mechanism in Weak Acidic Aqueous Solutions


Автор: Kimon Zavitsanos, Konstantinos Tampouris, and Athinoula L. Petrou 
Рік видання: 2008. Тип документу: Складова частина документу 
Розмір: 739 Кб     Кількість завантажень: 41

Sequestration of Alkyltin(IV) Compounds in Aqueous Solution: Formation, Stability, and Empirical Relationships for the Binding of Dimethyltin(IV) Cation by N- and O-Donor Ligands


Автор: Agatino Casale, Concetta De Stefano, Giuseppe Manfredi, Demetrio Milea, and Silvio Sammartano 
Рік видання: 2009. Тип документу: Складова частина документу 
Розмір: 1,04 Мб     Кількість завантажень: 41

Synthesis and Biological Evaluation of New CRH Analogues

A series of 7 new human/rat Corticotropin Releasing Hormone (h/r-CRH) analogues were synthesized. The induced alterations include substitution of Phe at position 12 with D-Phe, Leu at positions 14 and 15 with Aib and Met at positions 21 and 38 with Cys(Et) and Cys(Pr). The analogues were tested regarding their binding affinity to the CRH-1 receptor and their activity which is represented by means of percentage of maximum response in comparison to the native molecule. The results indicated that the introduction of Aib, or Cys derivatives although altering the secondary structure of the molecule, did not hinder receptor recognition and binding.
Автор: Spyridon Papazacharias, Vassiliki Magafa, Nicole Bernad, George Pairas, Georgios A. Spyroulias, Jean Martinez, and Paul Cordopatis 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 690 Кб     Кількість завантажень: 41

Complexes of Cu(II) Ions and Noncovalent Interactions in Systems with L-Aspartic Acid and Cytidine-5’-Monophosphate


Автор: Romualda Bregier-Jarzebowska, Anna Gasowska, and Lechosław Lomozik 
Рік видання: 2008. Тип документу: Складова частина документу 
Розмір: 877 Кб     Кількість завантажень: 41

Cu(II) and Ni(II) Interactions with the Terminally Blocked Hexapeptide Ac-Leu-Ala-His-Tyr-Asn-Lys-amide Model of Histone H2B (80–85)


Автор: Katerina Panagiotou, Maria Panagopoulou, Tilemachos Karavelas, Vassiliki Dokorou, Andrew Hagarman, Jonathan Soffer, Reinhard Schweitzer-Stenner, GerasimosMalandrinos, and Nick Hadjiliadis 
Рік видання: 2008. Тип документу: Складова частина документу 
Розмір: 980 Кб     Кількість завантажень: 41

Coal Depolymerising Activity and Haloperoxidase Activity of Mn Peroxidase fromFomes durissimus MTCC-1173


Автор: Sunil Kumar Singh,Meera Yadav, Sudha Yadava, and Kapil Deo Singh Yadav 
Рік видання: 2011. Тип документу: Складова частина документу 
Розмір: 1,02 Мб     Кількість завантажень: 41

Biological and Clinical Aspects of Lanthanide Coordination Compounds


Автор: Sudhindra N. Misra, Minaz A.Gagnani, Indira Devi M. and Ram S. Shukla 
Рік видання: 2004. Тип документу: Складова частина документу 
Розмір: 3,89 Мб     Кількість завантажень: 41

Synthesis, X-Ray Structure, and Characterization of Catena - bis(benzoate)bis{N,N-bis(2-hydroxyethyl)glycinate}cadmium(II)


Автор: Eugenia Katsoulakou, Konstantis F. Konidaris, Catherine P. Raptopoulou, Vassilis Psyharis, Evy Manessi-Zoupa, and Spyros P. Perlepes 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,91 Мб     Кількість завантажень: 41

Stabilization of Curcumin by Complexation with Divalent Cations in Glycerol/Water System


Автор: Bachar Zebib, Zephirin Mouloungui, and Virginie Noirot 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,54 Мб     Кількість завантажень: 41

The Δ33-35Mutant α-Domain Containing β-Domain-LikeM3S9 Cluster Exhibits the Function of α-Domain withM4S11 Cluster in Human Growth Inhibitory Factor

Neuronal growth inhibitory factor (GIF), also known as metallothionein (metallothionein-3), impairs the survival and neurite formation of cultured neurons. It is known that the α-β domain-domain interaction of hGIF is crucial to the neuron growth inhibitory bioactivity although the exact mechanism is not clear. Herein, the β(MT3)-β(MT3) mutant and the hGIF-truncated Δ33-35 mutant were constructed, and their biochemical properties were characterized by pH titration, EDTA, and DTNB reactions. Their inhibitory activity toward neuron survival and neurite extension was also examined. We found that the Δ33- 35 mutant α-domain containing β-domain-like M3S9 cluster exhibits the function of α-domain with M4S11 cluster in hGIF. These results showed that the stability and solvent accessibility of themetal-thiolate cluster in β-domain is very significant to the neuronal growth inhibitory activity of hGIF and also indicated that the particular primary structure of α-domain is pivotal to domaindomain interaction in hGIF.
Автор: Qingui Bao, Zhichun Ding, Zhong-Xian Huang, and Xiangshi Tan 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 707 Кб     Кількість завантажень: 41

Synthesis and Characterization of a New Cobalt(ll) Complex with 2-(2-Pyridyl)Imino-N-(2-Thiazolin-2- yl)Thiazolidine (PyTT)

The complex [Co(NO3)(PyTT)2(H20)]NO3 has been isolated and characterized by single crystal X-ray diffraction, IR spectroscopy, UV-Vis-NIR diffuse reflectance and magnetic susceptibility measurements. The environment around the cobalt atom may be described as a distorted octahedral geometry with the metallic atom coordinated to two thiazoline nitrogens, two imino nitrogens, one oxygen atom of a nitrate group monodentate and the oxygen atom of a water molecule.
Автор: A. Bernalte-Garcia, F.J. Garcia-Barros, F.J. Higes-Rolando, F. Luna-Giles, M.M. Pacheco- Rodfiguez and E. Vifiuelas-Zahinos 
Рік видання: 2004. Тип документу: Складова частина документу 
Розмір: 950 Кб     Кількість завантажень: 41

Cationic Porphyrin Induced a Telomeric DNA to G-Quadruplex Form inWater

The formation of the DNA G-quadruplex is induced by the addition of a novel porphyrin carrying four cationic tethers. Circular dichroism spectroscopy reveals that the porphyrin binds to Tetrahymena telomeric repeat to formG-quadruplex under stabilizingcation- deficient and no buffer conditions.
Автор: Takashi Murashima, Daichi Sakiyama, Daisuke Miyoshi, Masanori Kuriyama, Takashi Yamada, Toshifumi Miyazawa and Naoki Sugimoto 
Рік видання: 2008. Тип документу: Складова частина документу 
Розмір: 653 Кб     Кількість завантажень: 41

Alkali-Ion-Crown Ether in Art and Conservation: The Applied Bioinorganic Chemistry Approach

Dried varnish is rich in many ester moieties, which may be broken down into small, soluble compounds by esterase activity or alkaline hydrolysis. Two methods for varnish removal have been developed, including the treatment of either lipase or RbOH PEG-400 crown ether which allow aged oil varnishes or paint coverings to be removed or thinned. These techniques are designed to proceed in a controlled manner without damaging lower paint or base layers. Unfortunately, lipase did not react with the aged ester groups of dried linseed oil varnish. Surprisingly, the varnish came off in the presence of Tris buffer alone which, in addition, formed reactive metal complexes. A better choice was the use of high Mr alkali ion polyethylene glycol- 400 (PEG-400) crown ether type chelates. PEG-400 complexes alkali ions including rubidium and other alkaliions impeding the diffusion of their basic counter ions into lower varnish or paint layers. Possible migration of alkali metal ions into the paint layer during alkaline varnish removal was determined by labelling the cleansing solutions with 86Rb. Fortunately, varnish is degraded on the surface only. Lower paint or varnish layers are not attacked even if chemically similar to the varnish or over painting to be removed as virtually no 86Rb was detected on the paint surface.
Автор: Uwe Hilfrich, Harold Taylor, Ulrich Weser 
Рік видання: 2004. Тип документу: Складова частина документу 
Розмір: 5,33 Мб     Кількість завантажень: 41

Effect of Poly (Sodium 4-Styrene Sulfonate) on theMorphology of Hydroxyapatite Particles

Nanorods hydroxyapatite, (HAP) Ca10(PO4)6(OH)2 is successfully prepared by water in oil microemulsion using, CaCL2 and H3PO4 (water phase), poly(sodium 4-styrene sulfonate) (PSSS) as template and cyclohexane as oil phase. The nano-structure of the product was studied by means of X-ray diffraction (XRD), Fourier transmission infrared spectrometer (FT-IR), scanning electron microscopy (SEM), and atomic force microscope (AFM). With this system, we could synthesize nano-particles of hydroxyapatite with high crystallinity and least agglomeration.
Автор: Nesa Esmaeilian Tari andMohammadMahdi KashaniMotlagh 
Рік видання: 2009. Тип документу: Складова частина документу 
Розмір: 925 Кб     Кількість завантажень: 41

Degradation of Single Stranded Nucleic Acids by the Chemical Nuclease Activity of the Metal Complex [Cu(phen)(nal)]/

The chemical design of metal complexes of the type [Cu(phen)(antib)]+ (where antib is a quinolone or a fluoroquinolone) has been carried out in an approach to better understand how the coordination of their components affect the activity of quinolones. The ability of [Cu(phen)(nal)]+ to interact with DNA in vivo and its capacity to promote the degradation of plasmid and chromosomal DNA, under reductive conditions has been previously reported. However whether this compound utilizes other intracellular targets to promote bacterial killing was a question that deserved to be answered. In this paper, the studies of the chemical nuclease properties encoded by the metal complex [Cu(phen)(nal)]+ were extended by using different types of single chain nucleic acids, i.e, ribosomal and tumor mosaic virus RNAs as well as poly-dA-dT.
Автор: Norma Ramirez-Ramfl’ez, Guillermo Mendoza-Diaz, Mario Pedraza-Reyes 
Рік видання: 2002. Тип документу: Складова частина документу 
Розмір: 1,60 Мб     Кількість завантажень: 41

Selectivity of Inhibition of N-Succinyl-l,l-Diaminopimelic Acid Desuccinylase in Bacteria : The product of dapE-gene Is Not the Target of l-Captopril Antimicrobial Activity

The emergence of bacterial strains that are resistant to virtually all currently available antibiotics underscores the importance of developing new antimicrobial compounds. N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) is a metallohydrolase involved in the meso-diaminopimelate (mDAP)/lysine biosynthetic pathway necessary for lysine biosynthesis and for building the peptidoglycan cell wall. Because DapE is essential for Gram-negative and some Gram-positive bacteria, DapE has been proposed as a good target for antibiotic development. Recently, l-captopril has been suggested as a lead compound for inhibition of DapE, although its selectivity for this enzyme target in bacteria remains unclear (Gillner et al. (2009)).
Автор: Narasimha Rao Uda andMarc Creus 
Рік видання: 2011. Тип документу: Складова частина документу 
Розмір: 2,57 Мб     Кількість завантажень: 41

Niobium Uptake and Release by Bacterial Ferric Ion Binding Protein

Ferric ion binding proteins (Fbps) transport FeIII across the periplasm and are vital for the virulence of many Gram negative bacteria. Iron(III) is tightly bound in a hinged binding cleft with octahedral coordination geometry involving binding to protein side chains (including tyrosinate residues) together with a synergistic anion such as phosphate. Niobium compounds are of interest for their potential biological activity, which has been little explored. We have studied the binding of cyclopentadienyl and nitrilotriacetato NbV complexes to the Fbp from Neisseria gonorrhoeae by UV-vis spectroscopy, chromatography, ICP-OES, mass spectrometry, and Nb K-edge X-ray absorption spectroscopy. These data suggest that NbV binds strongly to Fbp and that a dinuclear NbV centre can be readily accommodated in the interdomain binding cleft. The possibility of designing niobium-based antibiotics which block iron uptake by pathogenic bacteria is discussed.
Автор: Yanbo Shi, Ian Harvey, Dominic Campopiano, and Peter J. Sadler 
Рік видання: 2010. Тип документу: Складова частина документу 
Розмір: 1,11 Мб     Кількість завантажень: 41