J. Serb. Chem. Soc. 74 (6) 607–618 (2009)
UDC 633.12:577.112.386:547.964.2; JSCS–3859; doi: 10.2298/JSC0906607M; Original scientific paper

Successful production of recombinant buckwheat cysteine-rich aspartic protease in Escherichia coli
MIRA D. MILISAVLJEVIĆ*, DRAŽEN R. PAPIĆ*^,**, GORDANA S. TIMOTIJEVIĆ* and VESNA R. MAKSIMOVIĆ*
*Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, P.O. Box 23, 11010 Belgrade, Serbia

**Interfaculty Institute for Biochemistry, University of Tübingen, 72076 Tübingen, Germany

(Received 23 January, revised 10 March 2009)

Herein, the expression of recombinant cysteine-rich atypical buckwheat (Fagopyrum esculentum) aspartic protease (FeAPL1) in five Escherichia coli strains differing in their expression capabilities is presented. It was shown that the expression success depended highly on the choice of FeAPL1 fusion partner. His6-FeAPL1 was produced in large quantities as an insoluble protein localized in inclusion bodies. On the other hand, MBP-FeAPL1 was localized in both the cytoplasm and inclusion bodies in BL21 and Rosetta-gAMi strains. Only purified soluble MBP-FeAPL1 from Rosetta-gAMi cells showed proteolytic activity at pH 3.0 with BSA as the substrate. The results also indicated that FeAPL1 contained a PRO segment that had to be removed for the enzyme activity to appear. The activity of FeAPL1 produced in the Rosetta-gAMi strain, which enables disulfide bond formation indicated the importance of the twelve cysteine residues for correct folding and functionality.

Keywords: aspartic protease; His tag; inclusion bodies; MBP; recombinant protein.

J. Serb. Chem. Soc. 74 (6) 619–628 (2009)
UDC 582.272+551.468(262.4):615.28–188: 665.52/54; JSCS–3860; doi: 10.2298/JSC0906619D; Original scientific paper

Antimicrobial and antioxidant activity of brown algae from the Aegean Sea
ZELIHA DEMIREL, FERDA F. YILMAZ-KOZ*, ULKU N. KARABAY-YAVASOGLU, GUVEN OZDEMIR and ATAKAN SUKATAR
Ege University, Faculty of Science, Department of Biology, Izmir, Turkey

*Ege University, Faculty of Pharmacy, Department of Pharmaceutical Microbiology, Izmir, Turkey

(Received 9 December 2008, revised 26 January 2009)

The present study was conducted to evaluate the antioxidant and antimicrobial activity of methanol, dichloromethane and hexane extracts, as well as the essential oils of brown algae (Phaeophyta) Colpomenia sinuosa, Dictyota dichotoma, Dictyota dichotoma var. implexa, Petalonia fascia and Scytosiphon lomentaria. The essential oil of the macroalgae was obtained by steAM distillation and analyzed by GC and GC/MS. The antioxidant activity of the algal extracts was determined using the procedures of inhibition of b-carotene bleaching and ABTS⁺ methods. The antioxidant effects of the extracts were compared with those of commercial antioxidants, such as butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA) and a-tocopherol. The hexane extracts of D. dichofoma var. implexa had a higher phenolic content than the other extracts. The dichloromethane extract of S. lomentaria was found to be more active in the decolorization of ABTS⁺ than the other extracts and generally the dichloromethane extracts were more active than the methanol and hexane extracts. Antimicrobial activities of the extracts were assessed against GrAM (+) and GrAM (–) bacteria and one yeast strain by the disk diffusion method. According to the results, the dichloromethane extracts generally showed more potent antimicrobial activity than the methanol and hexane extracts at concentrations 1.5 and 1.0 mg/disk.

Keywords: brown algae; antioxidant activity; antimicrobial activity; essential oil.

J. Serb. Chem. Soc. 74 (6) 629–640 (2009)
UDC 546.732+547–304.4+547.466; JSCS–3861; doi: 10.2298/JSC0906629V;  Original scientific paper

A study of novel cobalt(II) octaazAMacrocyclic complexes with AMinocarboxylates or their derivativ
GORDANA VUČKOVIĆ, SLAĐANA B. TANASKOVIĆ*, MIRJANA ANTONIJEVIĆ-NIKOLIĆ**, VUKOSAVA ŽIVKOVIĆ-RADOVANOVIĆ and GORDANA GOJGIĆ-CVIJOVIĆ***

Faculty of Chemistry, University of Belgrade, P.O. Box 158, 11001 Belgrade, Serbia

*Faculty of Pharmacy, Vojvode Stepe 450, 11000 Belgrade, Serbia

**Higher Technological School of Professional Studies, 15000 Šabac

***Institute of Chemistry, Technology and Metallurgy, Department of Chemistry, Njegoševa 12, P. O. Box 473, Belgrade, Serbia

(Received 26 December 2008, revised 27 February 2009)

Four new air-stable mixed-ligand Co(II) complexes having the general formula [Co₂(Y)tpmc]Z₃×q(H₂O/CH₃CN) (HY = N-methylglycine/N,N-dimethylglycine, Z =  BF₄^-, qH₂O = 4 or 3; HY = S-norvaline/S-valine Z = ClO₄^- , qCH₃CN = 0.5; qH₂O = 0.5; tpmc = N,N’,N’’,N’’’-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) were prepared. The composition, some physical and chemical properties and their tentative geometries were evaluated based on elemental analysis (C, H, N), conductometric and magnetic measurements, spectroscopic data (UV/Vis, IR) and cyclic voltAMmetry. The data were compared with earlier described analogous complexes containing the macrocyclic ligand and aliphatic AMinocarboxylates. It is assumed that all complexes are binuclear with an exo coordination mode of the octaazAMacrocyclic pendant ligand in the boat conformation. In addition, two –N–(CH₂)₂–N– portions of the cyclAM ring within the tpmc ligand and Co(II) ions in the high-spin state are most probably bridged via oxygen atoms from the anion of the AMino-carboxylate/derivatives, whereas nitrogen atoms rest uncoordinated. In all cases, a combined chelate-bridged coordination is proposed as the most probable. The complexes were electrochemically stable in the potential range –1.0 to 1.0 V. They were also preliminary assayed toward some microorganisms together with the ligands, starting simple salts and solvents as test substances. In some cases, certain antimicrobial activity of the complexes was detected.

Keywords: cobalt(II) complexes; pendant octaazAMacrocycle; AMinocarboxylates and derivatives.

J. Serb. Chem. Soc. 74 (6) 641–650 (2009)
UDC 547.759.32–386+546.732’742’472: 535.33.004.12:537.621; JSCS–3862; doi: 10.2298/JSC0906641D; Original scientific paper

Estimation of the dipole moments of the excited state of di(2-methyl-6-chlorophenyl)carbazone and its Co(II), Ni(II) and Zn(II) complexes from the effect of solvent on their ultraviolet absorption spectra
ASHOK F. DODAMANI, MOHAMMEDSHAFI A. PHANIBAND and SHREEDHAR D. DHUMWAD
Department of Chemistry, Karnatak University’s Karnatak Science College, Dharwad-580001, Karnataka, India

(Received 15 October, revised 17 December 2008)

Di(2-methyl-6-chlorophenyl)carbazone (2M6CPC) and its Co(II), Ni(II) and Zn(II) complexes were synthesized and characterized by magnetic moment, and infrared and ¹H-NMR spectral measurements. The solvent effect in a series of polar and non-polar solvents of varying dielectric constants and refractive indices was estimated by recording the electronic spectra (S1 band) of the above compounds. The data was used to determine the magnitude and direction of the electric dipole moments in the first electronically excited state. The results indicate that the observed band systems in these compounds may be attributed to a π→π* transition.

Keywords: carbazone; electric dipole moments; dielectric constants; π→π* transition.

J. Serb. Chem. Soc. 74 (6) 651–661 (2009)

J. Serb. Chem. Soc. 74 (6) 663–668 (2009)        

J. Serb. Chem. Soc. 74 (6) 669–676 (2009)

UDC 547.783:543.544.5:665.58; JSCS–3865; 10.2298/JSC0906669M; Original scientific paper

J. Serb. Chem. Soc. 74 (6) 677–688 (2009)

UDC 543.544+66.097.8+577.15:577.121; JSCS–3866; doi: 10.2298/JSC0906677O; Original scientific paper

Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites

JADRANKA ODOVIĆ, MIRJANA ALEKSIĆ, BILJANA STOJIMIROVIĆ*, DUŠANKA MILOJKOVIĆ-OPSENICA** and ŽIVOSLAV TEŠIĆ**

Faculty of Pharmacy, University of Belgrade, P.O. Box 146, 11001 Belgrade, Serbia

*School of Medicine, University of Belgrade, P.O. Box 840, 11000 Belgrade, Serbia

**Faculty of Chemistry, University of Belgrade, P.O. Box 51, 11158 Belgrade, Serbia

(Received 16 October 2008)

The separation and chromatographic behaviour of five ACE (angiotensin converting enzyme) inhibitors and their four active metabolites were investigated by normal-phase thin-layer chromatography on silica using several mono- and binary non-aqueous solvent systems. The linear relationship between the R_M values and the composition of employed mobile phase was obtained. The hydrophobicity parAMeters R_M⁰ and C₀ were determined from the regression data of the plots, analogous to reversed-phase chromatography. The chromatographically obtained hydrophobicity parAMeters were correlated with the calculated log P values. The current results were correlated with the lipophilicity of the studied ACE inhibitors and their metabolites, previously estimated by reversed-phase chromatography.

Keywords: ACE inhibitors; normal-phase thin-layer chromatography; hydrophobicity.

J. Serb. Chem. Soc. 74 (6) 689–696 (2009)        

UDC 632.951+541.135.5–0.34.21:544.6.004.12; JSCS–3867, doi: 10.2298/JSC0906689N; Original scientific paper

Cross-section analysis of the morphology of electrodeposited copper obtained in the hydrogen co-deposition range

NEBOJŠA D. NIKOLIĆ*, VESNA M. MAKSIMOVIĆ**, MIOMIR G. PAVLOVIĆ* and KONSTANTIN I. POPOV*_,***

*ICTM – Institute of Electrochemistry, University of Belgrade, Njegoševa 12, P.O. Box 473, 11001 Belgrade, Serbia

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

***Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, P.O. Box 3503, 11001 Belgrade, Serbia

(Received 26 December 2008, revised 13 February 2009)

Cross-section analysis of copper deposits electrodeposited in the hydrogen co-deposition range at a constant overpotential and in a pulsating overpotential (PO) regime was performed. It was shown that a complete structural analysis of these technologically very important electrodes is impossible without an analysis of their internal structure. An insight into the compactness (or porosity) of the deposits, as well as into the depth of the holes, can only be obtained by this type of analysis.

Keywords: electrodeposition; cross-section analysis; hydrogen; copper.

J. Serb. Chem. Soc. 74 (6) 697–706 (2009)

UDC 549.25+504.521;351.777.83+628.516(497.11); JSCS–3868; doi: 10.2298/JSC0906697M; Original scientific paper

Heavy metals concentration in soils from parks and green areas in Belgrade

MIRJANA D. MARJANOVIĆ, MARIJA M. VUKČEVIĆ, DUŠAN G. ANTONOVIĆ, SUZANA I. DIMITRIJEVIĆ, ĐORĐE M. JOVANOVIĆ*, MILAN N. MATAVULJ** and MIRJANA Đ. RISTIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade, Serbia

*Ministry of Environmental Protection, Republic of Serbia, Omladinskih Brigada 1, Belgrade, Serbia

**Faculty of Sciences, University of Novi Sad, Trg D. Obradovića 2, Novi Sad, Serbia

(Received 4 September, revised 31 October 2008)

The current study included the investigation of several metals and their distribution in urban soils from parks and green areas in the city of Belgrade. The soils were sAMpled in January and February 2008. The concentrations of Cd, Co, Cu, Pb, Mn and Zn were measured, as well as the pH values and organic matter contents. The obtained results showed that there was a significant level of contAMination in some sAMples, especially with lead, and that it was most probably caused by anthropogenic activities, mostly from traffic. The results were compared with the National legislation and Netherlands standards. Also, the recent results were compared with the data from previous work and it was concluded that there has been a certain increase of the Pb concentration in the past three years. The level of pollution in playground soil was very high and each analyzed sAMple exceeded the Dutch target value for Cd, Co and Pb.

Keywords: pseudo-total metal contents; urban soil; parks; green areas; pollution.

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