JSCS - Vol 64, No1

JSCS Vol 64, No. 1

J. Serb. Chem. Soc. 64(1) 1-7 (1999)
UDC 547.587.51:615.281
JSCS-2616
Original scientific paper

A novel synthesis of heterocyclic compounds containing coumarin moiety of potential antimicrobial activity

M. E. ABD EL-FATTAH

Chemistry Department, Faculty of Science, Suez Canal University, Ismaillia, Egypt

(Received 8 July 1998)
The chemical reaction of 4-methyl-2-oxo-2H-benzopyran-7-yloxyacetic acid hydrazide (2) with some different reagents, such as anhydride compounds, aromatic aldehydes, carbon disulphide, and nitrous acid, yielded the corresponding phthalazine derivatives 3, 4, 5, hydrazone derivatives 6a-c, 1,3,4-oxadiazol derivative 8 and acid azide 10, respectively. Treatment of 10 with absolute alcohols, amines and ethyl amino acid esters gave the corresponding carbamate derivatives 11a,b, substituted urea derivatives 12a,b, and substituted ethyl acetate 13a-c, respectively. The biological activities of some of the synthesized compounds were evaluated.

Key words: heterocycles, coumarin, synthesis, antimicrobiol activity.

J. Serb. Chem. Soc. 64(1) 9-18 (1999)
UDC 547.772.2/.779
JSCS-2617
Original scientific paper

Synthesis and biological activity of some pyrazole derivatives

EL-SAYED H. EL-TAMANY, FAKHER A. EL-SHAHED and BELAL H. MOHAMED

Chemistry Department, Faculty of Science, Suez Canal University, Ismailia, Egypt

(Received 17 July 1998)
The 4-arylidene-3-methyl-1-phenyl-2-pyrazolinones 1a-c react with some active methylene compounds, under Michael reaction conditions, to give the pyrano[2,3-c] pyrazole derivatives 2-6. Reactions of 2a-c with some compounds were carried out. Ring-chain tautomerism with cleavage was observed in their reactions with some species. All the newly synthesized compounds were tested against some bacteria and some of the compounds were found to be biologically active.

Key words: pyrazoles, biological activity, ring-chain tautomerism.

J. Serb. Chem. Soc. 64(1) 21-30 (1999)
UDC 547.962:66.066.067:615.37
JSCS-2618
Original scientific paper

Isolation, purification and characterization of the flagellin Campylobacter jejuni PEN 19

DONKA LANGE-KOVACEVIC, STOJANKA ALEKSIC*, MIROSLAV M. VRVIC** and IVANKA KARADZIC***

Johnson & Johnson Medical, Ostrasse 1, 22844 Norderstedt, Germany,
*National Referent Zentrum fur Enteritis Erreger und Yersiniosen, Hygienisches Institut,
Marckmannstr. 129a, 20539 Hamburg, Germany,
**Faculty of Chemistry, University of Belgrade, Studentski trg 16, P.O.Box 158, 11001 Belgrade, Yugoslavia and
***School of Medicine, Institute of Chemistry, University of Belgrade, Visegradska 26, 11000 Belgrade, Yugoslavia

(Received 29 July, revised 5 November 1998)
Two different methods were used for the isolation and purification of the flagellin Campylobacter jejuni, serotype O19 (PEN 19). In the first method, the flagellin proteins were isolated and purified to homogeneity by mechanical shearing and differential ultracentrifugation. In the another method applied, the flagellin was isolated and purified by acid dissociation, differential ultracentrifugation, neutral pH reassociation and ammonium sulfate precipitation of the protein. The flagellin preparations were of a high degree of purity as demonstrated by transmission electron microscopy and SDS-PAGE. One single band with molecular mass 68 kD was obtained. Immunization of rabbits with the flagellin preparations produced antiserum with high H agglutination titters. Immunodiffusion and immunoelectrophoresis of the flagellin preparations exhibited single precipitation band indicating homogeneity.

Key words: Campylobacter jejuni, flagellin, TEM, SDS-PAGE, immunoelectrophoresis.

J. Serb. Chem. Soc. 64(1) 31-37 (1999)
UDC 547.415.1:546.73-541.426.49
JSCS-2619
Original scientific paper

Synthesis and characterization of uns-cis-(1,3-propane-diamine-N,N'-diacetato)cobalt(III) complexes with symmetrical b-diketonato ligands

SRECKO R. TRIFUNOVIC, NELA VUCKOVIC, SLOBODAN A. GRUJIC, ZIVOSLAV LJ. TESIC* and
TIBOR J. SABO*

Faculty of Science, Department of Chemistry, University of Kragujevac, P.O.Box 60, YU-34000 Kragujevac,
*Faculty of Chemistry, University of Belgrade, P.O.Box 158, YU-11001 Belgrade, Yugoslavia

(Received 26 August 1998)
The mixed uns-cis(b-diketonato)(1,3-propanediamine-N,N'-diacetato)cobalt(III) complexes (b-diketonato ligands = 2,4-pentanedione, 1,3-diphenyl-1,3-propanedione and 2,2,6,6-tetramethyl-3,5-heptanedione) were prepared by the reaction of sodium uns-cis-(1,3-propanediamine-N,N'-diacetato)(carbonato)cobaltate(III) and the corresponding symmetrical b-diketone at 75 °C. The complexes were isolated chromatographically and characterized by elemental analysis, infrared and electron absorption spectroscopy.

Key words: synthesis, cobalt(III) complexes, 1,3-propanediamine-N,N'-diacetic acid, b-diketonates.

J. Serb. Chem. Soc. 64(1) 39-45 (1999)
UDC 547.461/.2:661.8.465
JSCS-2620
Original scientific paper

Reaction between oxalic acid and Na₂HAsO₄. A conductometric and pH metric investigation

M. V. OBRADOVIC, S. S. MITIC, S. M. SUNARIC and D. S. VESELINOVIC*

Department of Chemistry, Faculty of Philosophy, University of Nis, YU-18000 Nis, and
*Faculty of Physical Chemistry, University of Belgrade, P.O.Box 137, YU-11001 Belgrade, Yugoslavia

(Received 10 July, revised 21 October 1998)
The reaction between Na₂HAsO₄ and oxalic acid was studied by pH-metric and conductometric measurements, applying the methods of continual variations. It was found that the oxalic acid forms a complex of the type [HAsO₃C₂O₄]^2- .The stability constants and thermodynamic parameters for the complex reaction were calculated using the data obtained by pH-metric measurements at 25±1 °C.

Key words: arsen(V), oxalic acid, complex, conductometry, pH-metry.

J. Serb. Chem .Soc. 64(1) 47-53 (1998)
UDC 541.138/.183.5:546.57/548.21/
JSCS-2621
Preliminary communication

PRELIMINARY COMMUNICATION
Electrosorption of bromide ions onto silver single crystals

B. M. JOVIC,1 D. M. DRAZIC* and V. D. JOVIC**

nstitute of Technical Science of the Serbian Academy of Sciences and Arts, YU-11001 P.O.Box 745, Belgrade,
*Institute of Electrochemistry ICTM, YU-11000, Njegoseva 12, Belgrade and
**Center for Multidisciplinary Studies, University of Belgrade, P.O. Box 33, YU-11030 Belgrade, Yugoslavia

(Received 22 September 1998)
Electrosorption of bromide ions onto the (111), (100) and (110) silver single crystal faces from solutions of different concentration was investigated by cyclic voltammetry. It was shown that the shape of the voltammograms depends significantly on the single crystal orientation and that in all cases a monolayer of AgBr of the corresponding orientation was formed as the final product of electrosorption process. By deconvolution of the CV peaks obtained on the (111) face and by their fitting with the Frumkin adsorption isotherm, it was shown that the electrosorption process takes place throught four different stages of the adsorbate, two of them (appearing at more negative potentials) being characterized by repulsive forces and the other two by attractive forces between the adsorbed species. By the analysis of the E_a,p - log n dependences, it was shown that, as in the case of chloride ions electrosorption, the mechanism of bromide electrosorption is complex, taking place through three or four steps, with the rate determining one being either the chemical reaction of AgBr formation, or the 2D crystallization of the AgBr layer.

Key words: electrosorption of Br^-, silver single crystals, Frumkin adsorption isotherm, 2D crystallization of AgBr.

J. Serb. Chem. Soc. 64(1) 55-60 (1999)
UDC 661.887:543.063/064
JSCS-2622
Original scientific paper

Kinetic determination of ultra micro amounts of Bi(III)

TODOR G. PECEV, RANGEL P. IGOV, VESNA P. STANKOV-JOVANOVIC and VIOLETA D. MITIC

Faculty of Philosophy, University of Nis, YU-18000 Nis, Yugoslavia

(Received 1 July, revised 9 October 1998)
The new indicator reaction is suggested and a new kinetic method developed for Bi(III) traces determination. We observed that Bi(III) ions have a catalytic influence on the hematoxylin (HT) oxidation process by hydrogen peroxide in perchloric acid solution. The sensitivity of the method is 0.08 µg cm^-3. The probable relative error is 2.3-10.5% for Bi(III) concentrations in the interval
0.08 µg cm ^-3 to 0.23 µg cm^-3. Kinetic equations for the uncatalysed and the catalytic processes were derived. The selectivity of the method is good. The method was applied for Bi(III) determination in aluminum containing traces of Ag. The obtained results are comparable with those obtained by the AAS hydride method.

Key words: kinetic determination, bismuth(III), hematoxylin.

J. Serb. Chem. Soc. 64(1) 61-69 (1999)
UDC 546.571:543.063/.064
JSCS-2623
Original scientific paper

Catalytic titrations of silver(I) applying the iodide-catalysed manganese(IV)-arsenic(III) indicator reaction in the presence of sulphuric acid

TIBOR J. PASTOR, VOJKA V. ANTONIJEVIC and FERENC T. PASTOR

Faculty of Chemistry, University of Belgrade, Akademski trg 12-16, P.O.Box 158, YU-11001 Belgrade, Yugoslavia

(Received 9 October 1998)
A new catalytic potentiometric titration method for the determination of silver(I), applying the iodide-catalysed manganese(IV)-arsenic(III) indicator reaction in the presence of sulphuric acid, has been developed. The effect of the concentration of sulphuric acid and different ions, and of the mole ratio of manganese(IV) to arsenic(III) in the titrated solution, as well as of the titrand temperature on the conditions for the determination of silver(I) in solutions of various concentrations, was investigated. The error in the determination of 0.5 µg cm^-3 silver(I) was less than 2%, with good reproducibility. Small quantities of 2-PAM iodide, as well as silver in a silver-zinc alloy were determined by the developed method.

Key words: catalytic potentiometric titration, silver(I), iodide, Mn(IV)-As(III) indicator reaction, sulphuric acid.

J. Serb. Chem. Soc.64(1) 71-82 (1999)
UDC 547.565.2:543.274
JSCS-2624
Technical paper

Expert system for catalytic titrimetry. Part. 3. Determination of monobasic non-carboxylic acids.

BILJANA F. ABRAMOVIC, BORISLAV K. ABRAMOVIC*, FERENC F. GAÁL and DANILO M. OBRADOVIC*

Institute of Chemistry, Faculty of Science, University of Novi Sad, Trg D. Obradovica 3, YU-21000 Novi Sad, and
*Computer, Control and Measurement Institute, Faculty of Technical Sciences, University of Novi Sad, Fruskogorska 11, YU-21000 Novi Sad, Yugoslavia

(Received 28 August 1998)
A part of the expert system (ES) to solve the problem of choosing a catalytic titrimetric procedure for the determination of monobasic non-carboxylic acids is described. The presented segment of the ES, on the basis of the behaviour of non-carboxylic acids in catalytic titrations using either different indicator reactions, or titrant and/or solvent on the one hand, and the possibility of their selective determination on the other, is divided into five modules. Each module encompasses a defined group of compounds, namely: phenols and naphthols, thiols, sulphonamides, keto-enols and imides, and thioamides and other.

Key words: expert system, catalytic titrations, monobasic non-carboxylic acids, selective determination.

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