Zinc(II) and cadmium(II) complexes with <Emphasis Type="Italic">o</Emphasis>-hydroxybenzoic acid or <Emphasis Type="Italic">o</Emphasis>-aminobenzoic acid and 2-methylimidazole

Mixed complexes of the type: Zn(Hsal)₂(2-MeHim)₂, Zn(Han)₂(2-MeHim)₂, Cd(Hsal)₂(2-MeHim)₂, Cd(Han)₂(2-MeHim)₂, where Hsal=OHC₆H₄COO⁻, Han=NH₂C₆H₄COO⁻, 2-MeHim=2-methylimidazol) have been synthesized and characterized by IR spectroscopic and X-ray diffraction studies. Single-crystal X-ray structure of Cd(Hsal)₂(2-MeHim)₂ has been obtained. Thermal behaviour of the compounds was investigated by thermal analysis (TG, DTG, DTA). A coupled TG-MS system was used to analyse the principal volatile products of complexes. Thermal decomposition pathways have been postulated.     

Molecular structure of di-<Emphasis Type="Italic">tert</Emphasis>-butylamine-containing the monoedge-functionalized clathrochelate iron(II) <Emphasis Type="Italic">tris</Emphasis>-dioximate

The structure of 1,8-bis(fluoroboro)-2,7,9,14,15,20-hexaoxa-3,6,10,13,16,19-hexaaza-4,5,11,12-tetraphenyl-17,18-bisc(tert-butylamino)-bicyclo[6.6.6]eicosa-3,5,10,12,16,18-hexaene(2−)iron(2+) tris-dioximate clathrochelate was determined by X-ray diffraction (XRD) analysis. The compound has a molecular structure and crystallizes as triclinic crystals: a = 10.7673(2) Å, b = 11.9520(4) Å, c = 22.5473(7) Å, α = 75.729(1)°, β = 89.161(1)°, γ = 65.334(1)°, V = 2542.64(13) ų, Z = 2, space group 1. P1ˉ. Original Russian Text Copyright ? 2007 by A. B. Burdukov, N. V. Pervukhina, M. A. Vershinin, and Ya. Z. Voloshin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No. 2, pp. 366–369, March–April, 2007.     

Functional Expression of <Emphasis Type="Italic">Bacillus anthracis</Emphasis> Protective Antigen in <Emphasis Type="Italic">E. coli</Emphasis>

The protective antigen (PA) of Bacillus anthracis is a potent immunogen and an important candidate vaccine. In addition, it is used in monitoring systems like enzyme-linked immunosorbent assay to assess antibodies against PA in immunized subjects. The low level of PA production in B. anthracis and the difficulty of separating it from other bacterial components have made the researchers do different studies with the aim of producing recombinant PA (rPA). In this study, to produce rPA as a recombinant protein vaccine, the partial sequence of protective antigen of B. anthracis, amino acids 175–764, as a potent immunogenic target was inserted in pET21b(+). This is a prokaryotic plasmid that carries an N-terminal T7.tag sequence. The integrity of constructed plasmid was confirmed using restriction enzyme mapping. rPA was expressed after induction with isopropyl β-d-1-thiogalactopyranoside in Escherichia coli BL21. Purification of rPA was done with an affinity system using anti T7.tag antibody. Electrophoresis and Western blotting confirmed the specificity of the expressed protein. BALB/c mice were immunized with obtained PA protein and evaluation of specific immunoglobulin G antibodies against PA in sera using Western blotting method and showed that rPA is immunogenic. The challenge of immunized mice with virulent strain of B. anthracis showed that rPA is functional to protect against pathogenic strain.     

Inhibitory study of two cephalosporins on <Emphasis Type="Italic">E. coli</Emphasis> by microcalorimetry

The microcalorimetric method has been used to study the effects of cefpiramide and ceftizoxime sodium on the E. coli growth. The results revealed that these two cephalosporins may alter the metabolic way of the E. coli. Moreover, the lethal doses of cefpiramide and ceftizoxime sodium are 2.000 and 0.2000 μg mL⁻¹, respectively. Combining with the relationships between growth rate constant (k), the maximum power output (P _m ), the time corresponding to the maximum power output (t _m ) and cephalosporins concentration (C), one can draw the conclusion that the ceftizoxime sodium has a stronger inhibition effects on the growth of E. coli than that of cefpiramide and they both have the possibility to induce the drug fever.     

Microcalorimetric investigation of the effect of berberine alkaloids from <Emphasis Type="Italic">Coptis chinensis</Emphasis> Franch on <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> growth

The inhibitory effects of three berberine alkaloids (BAs) from rhizome of Coptis chinensis Franch, a traditional Chinese medicinal (TCM) herb, on Staphylococcus aureus growth were investigated by microcalorimetry. The power-time curves of S. aureus with and without BAs were acquired; meanwhile the extent and duration of inhibitory effects on the metabolism were evaluated by studying the growth rate constant (k), half inhibitory ratio (IC₅₀), maximum heat-output power (P _max), peak time of maximum heat-output power (t _p) and total heat production (Q _t). The value of k of S. aureus in the presence of the three BAs decreased with the increasing concentrations of BAs. Moreover, P _max was reduced and the value of t _p increased with increasing concentrations of the three drugs. The inhibitory activity varied with different drugs. The values of IC₅₀ of the three BAs are respectively, 101.4 μg/mL for berberine, 241.0 μg/mL for palmatine and 792.3 μg/mL for jateorrhizine. The sequence of antimicrobial activity of the three BAs is: berberine > palmatine > jateorrhizine. It is suggested that the functional group methylenedioxy or methoxyl at C2 on the phenyl ring could possibly improve antimicrobial activity more strongly than hydroxyl at C2 on the phenyl ring. Supported by the National Natural Science Foundation of China (Grant No. 30625042)     

Three New 1D Polymeric Zinc(II) and Cadmium(II) Azido Complexes Containing Noncoordinated Pyridine-<Emphasis Type="Italic">N</Emphasis>-oxide or 3-Picoline-<Emphasis Type="Italic">N</Emphasis>-oxide

Summary. The interaction of pyridine-N-oxide (pyNO) and 3-picoline-N-oxide (3picNO) with zinc(II) and cadmium(II) azides afforded complexes with empirical formulae Zn(N₃)₂(pyNO)(H₂O)₂, Zn(N₃)₂(3picNO)₂(H₂O)₂ and Cd(N₃)₂(3picNO)₂(H₂O)₂. The IR spectra of these complexes are measured and discussed. X-Ray single crystal diffraction showed for the first complex, which should be formulated as {[Zn(N₃)₂(H₂O)₂](pyNO)}_n, to consist of 1D chains of trans-[Zn(N₃)₂(H₂O)₂]_n, double end-on (-1,1) azido bridges and noncoordinated pyNO molecules. The other two complexes are isomorphous containing 1D trans-[M(N₃)₂(H₂O)₂]_n, double (-1,1) azido bridges, and hydrogen bonded noncoordinated 3picNO molecules. Each pyridine-N-oxide molecule forms three hydrogen bonds, whereas the 3-picoline-N-oxides form two hydrogen bonds. The metal centers exhibit distorted octahedral geometry.Received March 5, 2003; accepted May 15, 2003 Published online September 11,2003     

Study of the growth of <Emphasis Type="Italic">Enterococcus faecalis</Emphasis>, <Emphasis Type="Italic">Escherichia coli</Emphasis> and their mixtures by microcalorimetry

In a majority of environments, microbes live as interacting communities. Microbial communities are composed of a mix of microbes with often unknown functions. Polymicrobial diseases represent the clinical and pathological manifestations induced by the presence of multiple infectious agents. These diseases are difficult to diagnose and treat and usually are more severe than monomicrobial infections. The interaction relationship between Enterococcus faecalis and Escherichia coli was researched using a Calvet calorimeter. Three mixtures of both bacteria were prepared in the following proportions: 20 + 80 % (0.2 mL E. faecalis + 0.8 mL E. coli), 50 + 50 % (0.5 mL E. faecalis + 0.5 mL E. coli) and 80 + 20 % (0.8 mL E. faecalis + 0.2 mL E. coli). Experiments were carried out at concentration of 10⁶ CFU mL^?1 and a constant temperature of 309.65 K. The differences in shape of graph of E. faecalis, E. coli and their mixtures were compared. Also, the thermokinetic parameters such as detection time (t _d), growth constant (k), generation time (G) and the amount of heat released (Q) were calculated.     

Microcalorimetric investigation of the growth of the engineering <Emphasis Type="Italic">BACILLUS</Emphasis><Emphasis Type="Italic">THURINGIENSIS</Emphasis> with different plasmid numbers and various promoters

A microcalorimetric technique based on the bacterial heat output was applied to evaluate the influence of plasmid copy number and various promoters on the green fluorescent protein expression in Bacillus thuringiensis. The thermogenic curves of the aerobic metabolism of B. thuringiensis strains were determined by using an LKB-2277 bioactivity monitor at 28°C. The analysis of the thermogenic curves indicated for the first time that the more plasmid copy number per cell the more protein synthetization. Promoter BtI-BtII had a stronger impact on the gene expression than promoter 3A investigated by the method of microcalorimetry.     

Crystal structure of copper(II) <Emphasis Type="Italic">trans</Emphasis>-bis-(4-phenyliminopentan-2-onate)

trans-Bis-(4-phenyliminopentan-2-onato)Cu(II) (5), which is a phenyl-substituted ketoimine, was synthesized, and an X-ray study was performed for this compound. Crystal data for CuN₂O₂C₂₂H₂₄: a = 11.4557(3) Å, b = 26.6845(9) Å, c = 14.2976(5) Å, β = 113.2270(10)°; space group P2₁/n, Z = 8, d _calc = 1.363 g/cm³, R = 0.033. The structure is molecular and built of isolated trans complexes. The central copper atom is surrounded by four atoms (2O+2N) with the average distances Cu-O 1.904(3) Å and Cu-N 1.962(3) Å. The polyhedron around the copper atom is a distorted tetrahedron; the average values of the O-Cu-O and N-Cu-N trans bond angles are 147(2)° and 150(2)°, respectively. The average value of the O-Cu-N angles is 94(1)°.     

Preparation and Characterization of Sulfadiazine <Emphasis Type="Italic">Schiff</Emphasis> Base Complexes of Co(II), Ni(II), Cu(II), and Mn(II)

Summary. Complexes of Co(II), Ni(II), Cu(II), and Mn(II) containing Schiff base NOS donor ligands have been synthesised via chemical and electrochemical techniques. The structure of the complexes has been elucidated by elemental analysis, conductance, magnetic susceptibility measurements, IR, ESR, electronic spectral studies and thermal techniques (TGA and DTA). The electrochemical behaviour of the metal complexes was studied using DC polarography and cyclic voltammetry. Antimicrobial activity of the title Schiff base and its complexes has been tested against different microorganisms.     

Study on the characterization of lead (II) biosorption by fungus <Emphasis Type="Italic">Aspergillus parasiticus</Emphasis>

The lead (II) biosorption potential of Aspergillus parasiticus fungal biomass has been investigated in a batch system. The initial pH, biosorbent dosage, contact time, initial metal ion concentrations and temperature were studied to optimize the biosorption conditions. The maximum lead (II) biosorption capacity of the fungal biosorbent was found as 4.02 × 10⁻⁴ mol g⁻¹ at pH 5.0 and 20°C. The biosorption equilibrium was reached in 70 min. Equilibrium biosorption data were followed by the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. In regeneration experiments, no significant loss of sorption performance was observed during four biosorption-desorption cycles. The interactions between lead (II) ions and biosorbent were also examined by FTIR and EDAX analysis. The results revealed that biosorption process could be described by ion exchange as dominant mechanism as well as complexation for this biosorbent. The ion exchange mechanism was confirmed by E value obtained from D-R isotherm model as well.     

<Emphasis Type="Italic">bis</Emphasis>(<Emphasis Type="Italic">N,N</Emphasis>-diethylnicotinamide) <Emphasis Type="Italic">p</Emphasis>-chlorobenzoate complexes of Ni(II), Zn(II) and Cd(II)

Three novel mixed ligand complexes of Ni(II), Zn(II) and Cd(II) with p-chlorobenzote and N,N-diethylnicotinamide were synthesised and characterized on the basis of elemental analysis, FTIR spectroscopic analysis, solid state UV-Vis spectrometric and magnetic susceptibility data. The thermal behavior of the complexes was studied by simultaneous TG-DTA methods in static air atmosphere and the mass spectra data were recorded. According to microanalytical results, formulas of complexes are C₃₄H₄₀N₄O₈ClNi, C₃₄H₄₀N₄O₈ClZn and C₃₄H₄₄N₄O₁₀ClCd. The complexes contain two moles of coordination waters, two moles p-chlorobenzoate and two mole N,N-diethylnicotinamide (dena) ligands per formula unit. In these complexes, the p-chlorobenzoate and N,N-diethylnicotinamide behave as monodentate ligand through acidic oxygen and nitrogen of pyridine ring. The decomposition pathways and the stability of the complexes are interpreted in the terms of the structural data. The final decomposition products were found to be as metal oxides.     

An Improved Stereocontrolled Route to <Emphasis Type="Italic">cis</Emphasis>-Erythrinanes by Combined Intramolecular <Emphasis Type="Italic">Strecker</Emphasis> and <Emphasis Type="Italic">Bruylants</Emphasis> Reaction

Summary. Condensation of (2-iodophenyl)ethylamines with cyclohexanoylacetaldehyde provided the corresponding aldimines which were reduced yielding secondary phenethylcyclohexanoylethylamines. These in turn were appropriate intermediates to prepare several erythrinanes by a sequential intramolecular Strecker and intramolecular Bruylants reaction. In contrast, the C-ring homologue schelhammeranes were not available on this route.Part of PhD thesis, LMU München, D     

Analysis of <Emphasis Type="Italic">Escherichia coli</Emphasis> nicotinate mononucleotide adenylyltransferase mutants <Emphasis Type="Italic">in vivo</Emphasis> and <Emphasis Type="Italic">in vitro</Emphasis>

Background  

Adenylation of nicotinate mononucleotide to nicotinate adenine dinucleotide is the penultimate step in NAD⁺ synthesis. In Escherichia coli, the enzyme nicotinate mononucleotide adenylyltransferase is encoded by the nadD gene. We have earlier made an initial characterization in vivo of two mutant enzymes, NadD72 and NadD74. Strains with either mutation have decreased intracellular levels of NAD⁺, especially for one of the alleles, nadD72.     

Synthesis of 6-methyl-8<Emphasis Type="Italic">H</Emphasis>-dibenzo[<Emphasis Type="Italic">a</Emphasis>,<Emphasis Type="Italic">g</Emphasis>]quinolizin-8-imines <Emphasis Type="Italic">via Reissert</Emphasis> compounds

Alkylation of Reissert compounds derived from 3-methylisoquinolines with several 2-cyanobenzylbromides followed by hydrolytic cleavage provided the corresponding 1-benzyl-3-methylisoquinolines. Treatment of the latter with methylmagnesiumiodide caused cyclization to the title compounds rather than formation of 2-acetylbenzylisoquinolines.     

<Emphasis Type="Italic">E. coli</Emphasis>, <Emphasis Type="Italic">P. aeruginosa</Emphasis>, and <Emphasis Type="Italic">B. cereus</Emphasis> Bacteria Sterilization Using Afterglow of Non-Thermal Plasma at Atmospheric Pressure

We developed and employed a new geometrical structure of dielectric barrier discharge in atmospheric pressure for bacterial broad spectrum sterilization. We utilized a plasma source having an AC power supply at 50 HZ and 5,400 V (rms value). We prepared suspensions of the Gram-negative bacteria species (Escherichia coli, Pseudomonas aeruginosa) and a Gram-positive of Bacillus cereus with Luria–Bertani broth media up to OD_600 nm = 0.25 of McFarland standard. Afterglow of non-thermal atmospheric pressure plasma treated these suspensions. The influence of the atmospheric plasma afterglow on the species was assayed in different time durations 5, 10, and 15 min. The spectroscopic results of this investigation indicated that the survival reduction of the species can reach to 100% for P. aeruginosa in an exposure time of 10 min, E. coli and B. cereus in an exposure time of 15 min.     

<Emphasis Type="Italic">Z</Emphasis>-and <Emphasis Type="Italic">E</Emphasis>-conformers of <Emphasis Type="Italic">N</Emphasis>-chloroacetylcytisine

N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated.     

Crystal and molecular structure of copper(II) <Emphasis Type="Italic">trans</Emphasis>-bis-(2-(methylimino)-4-pentanonate)

Synthesis and X-ray diffraction study of trans-bis-(2-(methylimino)-4-pentanonato)Cu(II), which is methyl-substituted ketoiminate, is reported. Crystal data for CuN₂O₂C₁₂H₂₀: a = 7.374(1) , b = 9.171(1) , c = 10.823(2) ; = 96.51(1)°, = 106.12(1)°, = 96.81(1)°, space group P , Z = 2, d _calc = 1.38 g/cm³, d _exp = 1.37 g/cm³, R = 0.037. The structure is molecular and consists of isolated trans-complexes. The coordination polyhedron of the copper atom is intermediate between the square and tetrahedron; the average distances are Cu-O 1.91 and Cu-N 1.95 , the O-Cu-O and N-Cu-N trans bond angles are 145.5° and 150.3°, respectively. The O-Cu-N chelate angle is 94.6°. The calculated energies of van der Waals intermolecular interactions are compared with the thermogravimetric characteristics of the complex with ketoiminate and copper(II) ethylenediamine-bis-acetylacetonate.Original Russian Text Copyright © 2004 by I. A. Baidina, P. A Stabnikov, A. D. Vasiliev, S. A. Gromilov, and I. K. IgumenovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 706–712, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

DNA Interaction with PtCl<Subscript>2</Subscript>(LL) (LL = Chelating Diamine Ligand: <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Dimethyltrimethylendiamine) Complex

The [PtCl₂(LL)] complex, as a cisplatin derivative, which LL is diamine chelate ligand (N,N-dimethyltrimethylendiamine), was synthesized and characterized by elemental analysis (CHN) mass, ¹H, and ¹³C nuclear magnetic resonance techniques. Then the binding of this complex to calf thymus DNA was investigated by various physicochemical methods such as spectrophotometric, circular dichroism, spectrofluorometric, melting temperature, and viscosimetric techniques. Upon addition of the complex, important changes were observed in the characteristic UV–Vis bands (hypochromism) of calf thymus DNA, increase in melting temperature and some changes in specific viscosity. Also, the fluorescence spectral characteristics showed an increase in the fluorescence intensity of methylene blue–DNA solutions in the presence of increasing amounts of metal complex, indicating PtCl₂(LL) is able to displace the methylene blue bound to DNA but not as complete as intercalative molecules. The experimental results showed that the platinum complex is bound to DNA non-intercalatively, and an outside binding is the preferred mode of interaction.     

Synthesis of Novel <Emphasis Type="Italic">D</Emphasis>-<Emphasis Type="Italic">Seco</Emphasis>-Pregnenes

Summary. A new synthetic route was developed for the preparation of trans-3-hydroxy-16,17-seco-pregna-5,17(20)-dien-16-al, using Grob fragmentation as the key step. This seco-steroid contains a formyl group and an unsaturated side-chain in a sterically favourable position, and is therefore a promising starting material for the synthesis of novel condensed steroid heterocycles.Received March 22, 2003; accepted April 22, 2003 Published online September 25, 2003