J. Serb. Chem. Soc. 74 (3) 223–235 (2009)
UDC 547.828+544.431.143+543.51; JSCS–3825; doi: 110.2298/JSC0903223M; Original scientific paper

ESI-MS spectra of 3-cyano-4-(substituted phenyl)-6-phenyl-2(1H)-pyridinones
ALEKSANDAR D. MARINKOVIĆ, TATJANA M. VASILJEVIĆ, MILA D. LAUŠEVIĆ and BRATISLAV Ž. JOVANOVIĆ
Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, P.O. Box 3503, 11120 Belgrade, Serbia

(Received 6 June, revised 24 October 2008)

Twelve 3-cyano-4-(substituted phenyl)-6-phenyl-2(1H)-pyridinones were investigated by tandem mass spectrometry using positive as well as negative electrospray ionization. The influence of the electron affinity of the substituent and the steric effect on the fragmentation is discussed. Pyridinones with a substituent of low proton affinity show loss of water, HCN or benzene from the pyridinone ring in the first step of MS² fragmentations. Oppositely, if a substituent with high proton affinity is present on the phenyl ring in the 4-position of pyridinone, the fragmentation paths are complex, depending mainly on the substituent proton acceptor ability. Elimination of neutral molecules CO, HCN, H₂O, PhH (benzene) or Ph and CN radicals are fragmentation processes common for all compounds in the subsequent steps of the fragmentations.

Keywords: electrospray ionization; substituted pyridinones; tandem mass spectrometry.

J. Serb. Chem. Soc. 74 (3) 237–244 (2009)
UDC 547.421+577.175.53+547.448:537.363; JSCS–3826; doi: 10.2298/JSC0903237P; Original scientific paper

Western blot analysis of glucocorticoid receptor phosphoisoforms by one- and two-dimensional electrophoretic assays
NATAŠA POPOVIĆ, ANA NIĆIFOROVIĆ, MIROSLAV ADŽIĆ, MARIJA B. RADOJČIĆ, CONSTANTINOS DEMONACOS* and MARIJA KRSTIĆ-DEMONACOS**
Vinča Institute of Nuclear Sciences, Department of Molecular Biology and Endocrinology, Belgrade, Serbia

*School of Pharmacy, University of Manchester, Manchester, United Kingdom

**Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom

(Received 17 October 2007, revised 27 August 2008)

The glucocorticoid receptor (GR) protein is a cytosolic ligand-dependent transcription factor with numerous functions regulated by post-translational modifications, including phosphorylation/dephosphorylation. Among the functions most extensively affected by GR phosphorylation are the modulation of its transcriptional activity, alterations in its interaction pattern with cofactors, nuclear translocation and selective gene transactivation. Intensive analysis of the intracellular distribution of GR phosphoisoforms and their interaction with proteins of other cellular signalling networks required the use of [g-³²P]ATP as a phosphate donor, and special laboratory protection measures to avoid external irradiation and contAMination. In the present study, simple and easy-to-use non-radioactive protein mobility shift assays (NMS assays) were developed using one- and/or two-dimensional gel electrophoresis based on differences in the pI and molecular mass of GR phosphoisoforms. The GR isoforms were immunodetected with specific monoclonal or polyclonal anti-GR antibodies by Western blot in three diverse systems, nAMely yeast BJ2168 cells expressing wild-type rat GR, rat hepatoma GRH2 cells grown in culture and brain tissue from Wistar rat experimental animals. The results obtained using the NMS assay were similar to previous results obtained with the [g-³²P] ATP standard assay.

Keywords: glucocorticoid receptor; phosphoisoforms; electrophoretic assay.

J. Serb. Chem. Soc. 74 (3) 245–257 (2009)
UDC 616.981.55+615.9+547.281.1+547.963.1; JSCS–3827; doi: 10.2298/JSC0903245I;  Original scientific paper

The monoclonal antibody 26 raised against tetanus toxoid also recognizes tetanus toxin and b₂-glycoprotein I – its binding properties in vitro and potential applications
ALEKSANDRA B. INIĆ-KANADA, MARIJANA M. STOJANOVIĆ, IRENA P. ŽIVKOVIĆ, VLADIMIR Ž. PETRUŠIĆ and LJILJANA A. DIMITRIJEVIĆ

Institute of Virology, Vaccines and Sera – Torlak, Vojvode Stepe 458, 11152 Belgrade, Serbia

(Received 17 July, revised 7 November 2008)

A murine monoclonal IgG1 antibody, marked as MAb26, specific for tetanus toxoid has been immunochemically characterized. By performing enzyme-linked immunosorbent assays (ELISAs) and western blot analyses, it was demonstrated that MAb26 reacted with tetanus toxoid, tetanus toxin and b₂-glycoprotein I (b₂GPI). According to the results, MAb26 recognized the sequential epitope on the tetanus heavy chain. The affinity constant, calculated from Scatchard plots of MAb26 binding to tetanus toxoid, was 1.145´10⁸ M^-1 and the measurement of the relative affinity of MAb26 by ELISA using thiocyanate elution showed a significantly higher affinity of MAb26 to the toxoid (p = 0.0012) in comparison to the toxin. Additionally, the reactivity of MAb26 toward the toxoid forms increased when the tetanus toxin was detoxified using 8 mM and higher formaldehyde concentrations. The similarity of the tetanus toxoid to several sera proteins, either at the level of its conformation (IL-1a) or at the level of peptide sequences (b₂GPI, lAMinin) favors its role in autoimmunity by the mechanism of molecular mimicry. As the induction of an autoimmune disease is dependent on the breakdown of tolerance, which could be the result of an overt hyperstimulation, the control of the presence and concentration of self-reactive epitopes in vaccine preparations is a prerequisite. In this study, it was shown that MAb26 can: 1) discriminate between the tetanus toxin and different toxoid forms, which makes it a good candidate for antibody control during vaccine preparation; 2) due to its cross-reactivity with b₂GPI, it could provide information on the presence of a potentially dangerous sequential epitope expressed at the protein surface.

Keywords: tetanus toxoid; tetanus toxin; monoclonal antibodies; formaldehyde.

J. Serb. Chem. Soc. 74 (3) 259–267 (2009)
UDC 547.594.4+547–326+546.742’562’472’:543.51; JSCS–3828; doi: 10.2298/JSC0903259U; Original scientific paper

Unsaturated b-ketoesters and their Ni(II), Cu(II) and Zn(II) complexes
MUHAMMED BASHEER UMMATHUR, KRISHNANNAIR KRISHNANKUTTY* and SINDHU BALAGOPAL*
Department of Chemistry, Unity Women’s College, Manjeri, Kerala-676122, India

*Department of Chemistry, University of Calicut, Kerala-673635, India

(Received 15 May, revised 14 July 2008)

A new series of b-ketoesters in which the keto group is attached to the olefinic linkage were synthesized by the reaction of methyl acetoacetate and aromatic aldehydes under specified conditions. The existence of these compounds predominantly in the intrAMolecularly hydrogen bonded enol form was well demonstrated from their IR, ¹H-NMR and mass spectral data. Details on the formation of their [ML₂] complexes with Ni(II), Cu(II) and Zn(II) and the nature of the bonding are discussed on the basis of analytical and spectral data.

Keywords: unsaturated b-ketoesters; metal complexes; IR; ¹H-NMR; mass spectra.

J. Serb. Chem. Soc. 74 (3) 269–277 (2009)

J. Serb. Chem. Soc. 74 (3) 279–289 (2009)

J. Serb. Chem. Soc. 74 (3) 291–299 (2009)

UDC 541.132+66.082.2:66.087+66.012; JSCS–3831; doi: 10.2298/JSC0903291Z; Original scientific paper

J. Serb. Chem. Soc. 74 (3) 301–310 (2009)

UDC 543.34:546.212+543.544.1:676.2; JSCS–3832; doi: 10.2298/JSC0903301Z; Original scientific paper

Determination of inorganic anions in papermaking waters by ion chromatography

DARJA ŽARKOVIĆ, ŽAKLINA TODOROVIĆ*, MILORAD KRGOVIĆ** and LJUBINKA RAJAKOVIĆ**

Belgrade Polytechnic, Brankova 17, 11000 Belgrade, Serbia

*Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia

**Faculty of Technology and Metallurgy, Karnegijeva 4, P.O. Box 494, 11000 Belgrade, Serbia

(Received 21 April, revised 1 August 2008)

A suppressed ion chromatography (IC) method for the determination of inorganic anions in process water from paperboard production was developed and validated. Common inorganic anions (Cl^-, NO₃^-, PO₄^3- and SO₄^2-) were detected in fresh and process water sAMples collected from a paperboard production system at 16 characteristic points. It was shown that the use of an IonPac^®-AS14 column under isocratic conditions with Na₂CO₃/NaHCO₃ as the eluent and a suppression device proved to be a reliable analytical solution for the separation of the inorganic anions present in papermaking waters. This IC method is quite satisfactory concerning selectivity and sensitivity, and enables the determination of several inorganic anions over a wide concentration range. According to the obtained results, the total AMount of analyzed inorganic anions was below 0.1 g/L, i.e., below the critical value which may trigger operational problems in paper production.

Keywords: papermaking waters; ion chromatography; inorganic anions.

J. Serb. Chem. Soc. 74 (3) 311–315 (2009)        

UDC 681.586.5:546.982–71:543.33/.34:66.094.25; JSCS–3833, doi: 10.2298/JSC0903311T; Short communication

SHORT COMMUNICATION

A novel optode sensor for the determination of palladium(II) in water and a hydrogenation catalyst

HOSSEIN TAVALLALI and MARYAM GHANAAT PISHEH JAHROMI

PayAMe Noor University (PNU), Shiraz, 71365-944, Iran

(Received 1 July, revised 16 September 2008)

A novel optical sensor was established to determine palladium(II) based on the immobilization of 1-(2-pyridylazo)-2-naphthol (PAN) on a triacetylcellulose membrane. Palladium ions react with the immobilized PAN and cause a decrease in the absorbance of the membrane at 469 nm. The response time of the optode was 8–10 min depending on the concentration of Pd(II) ions. This sensing phase had a dynAMic linear range of 0.10–12.0 µg ml^-1 palladium ions with a limit of detection of 65 ng ml^-1. The sensor can readily be regenerated using an ethylenediAMine solution. The sensor could be fully regenerated, and the color change was fully reversible. The method was successfully applied for the determination of Pd(II) in synthetic aqueous solutions and in a hydro-genation catalyst sAMple.

Keywords: optode; 1-(2-pyridylazo)-2-naphthol (PAN); palladium(II); hydro¬genation catalyst; triacetylcelluose.

J. Serb. Chem. Soc. 74 (3) 317–329 (2009)

UDC 547.261’122.6–31+547.534.2:532.12/.14; JSCS–3834; doi: 10.2298/JSC0903317C; Original scientific paper

Density, viscosity and refractive index of the dimethyl sulfoxide + o-xylene system

OANA CIOCIRLAN and OLGA IULIAN

Department of Applied Physical Chemistry and Electrochemistry, Faculty of Industrial Chemistry, “Politehnica” University of Bucharest, 313 Splaiul Independentei, 060042, Romania

(Received 10 April, revised 17 September 2008)

This work reports the experimental results of the densities, viscosities and refractive indices between 298.15 and 323.15 K of the dimethyl sulfoxide + o-xylene system over the entire composition range of the mixtures. The excess molar volumes (V^E), viscosity deviations (Δn), excess Gibbs energy of activation of viscous flow (G^*E) and deviations in the refraction (ΔR) were calculated from the experimental data; all the computed quantities were fitted to the Redlich–Kister equation. The system exhibits moderate negative values for the investigated excess properties. The resulting excess functions were interpreted in structural and interactional terms. From the experimental data, the thermodynAMic functions of the activation of viscous flow were estimated. The viscosity data were correlated with several semi-empirical equations. The two-parAMeter McAllister equation can give very good results.

Keywords: dimethyl sulfoxide; o-xylene; density; viscosity; excess properties.

J. Serb. Chem. Soc. 74 (3) 331–347 (2009)

UDC 666.942:620.193:546.226:519.87; JSCS–3835; doi: 10.2298/JSC0903331M; Original scientific paper

(NH₄)₂SO₄ corrosion of cement in concrete analyzed by an improved mathematical model

SAŠA MILETIĆ, MIRJANA ĐURIĆ*, ANDJELKA MIHAJLOV**, ĐORĐE BAŠIĆ** and ĐORĐE JANAĆKOVIĆ***

Galenika Fitofarmacija, Batajnički drum b.b., 11080 Zemun, Serbia

*Faculty of Technology, University of Novi Sad, 21000 Novi Sad, Bul. Cara Lazara 1, Serbia

**Faculty of Technical Sciences, University of Novi Sad, 21000 Novi Sad, Trg Dositeja Obradovića 6, Serbia

***Faculty of Techno¬logy and Metallurgy, University of Belgrade, 11000 Belgrade, Karnegijeva 4, Serbia

(Received 18 July, revised 21 October 2008)

This paper gives a critical analysis of the equation that predicts and estimates the progress of degradation for various building materials, recently proposed by Matsufuji et al. After the analysis, the paper suggests an improveed mathematical model, particularly for the modeling of sulfate corrosion. Experiments were performed with two sAMples of Portland cement and two sAMples of Portland cement with 30 % coal ash. The sAMples were immersed into a 10 % (NH₄)₂SO₄ solution and the concentration of SO₄^2- in the solution and the material was measured. As a parAMeter that quantifies cement degradation, the quantity of bonded SO₄^2- was suggested. According to the obtained data, mathematical models for the description of sulfate corrosion were defined for all the exAMined sAMples. The models were applied for the analysis of the behavior of ash and non-ash containing sAMples. They allowed a better explanation of degradation which occurred during the investigated time period and even further they showed that ash systems were significantly more resistant to sulfate corrosion.

Keywords: sulfate; corrosion; Portland cement; coal fly ash; mathematical model.

J. Serb. Chem. Soc. 74 (3) 349–357 (2009)

UDC 546.57–72:677.674/.675:677.027:615.281.004.12; JSCS–3836; doi: 10.2298/JSC0903349I; Original scientific paper

A study of the antibacterial efficiency and coloration of dyed polyAMide and polyester fabrics modified with colloidal Ag nanoparticles

VESNA ILIĆ, ZORAN ŠAPONJIĆ*, VESNA VODNIK*, DARKA MIHAILOVIĆ, PETAR JOVANČIĆ, JOVAN NEDELJKOVIĆ* and MAJA RADETIĆ*

Textile Engineering Department, Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade, Serbia

*Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia

(Received 3 September, revised 11 November 2008)

In this study, the influence of dyeing on the antibacterial efficiency of polyAMide and polyester fabrics loaded with colloidal Ag nanoparticles and the influence of the presence of Ag nanoparticles on the color change of dyed fabrics were investigated. Dyes C.I. acid green 25 and C.I. disperse blue 3 were used for dyeing of polyAMide fabrics, while dye C.I. disperse violet 8 was used for dyeing of polyester fabrics. The influence of Ag nanoparticles on the color change of polyAMide fabrics depends on the dye type, but generally it was lower compared to polyester fabrics. Polyester fabrics exhibited excellent antibacterial efficiency against GrAM-positive bacterium Staphylococcus aureus and GrAM-negative bacterium Escherichia coli, independent of the order of dyeing and Ag loading. PolyAMide fabrics provided a desirable level of antibacterial activity only if the Ag loading was performed after dyeing.

Keywords: Ag nanoparticles; polyester; polyAMide; antibacterial efficiency; color change.

Society Home Page