JSCS - Vol 73, No 5

JSCS Vol 73, No. 5

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J. Serb. Chem. Soc. 73 (5) 513–524 (2008)
UDC 547.77+542.913:547.97:66.022.39–035.8; JSCS–3732; doi: 10.2298/JSC0805513M; Original scientific paper

¹³C- and ¹H-NMR substituent-induced chemical shifts in N(1)-(4-substituted phenyl)-3-cyano-4,6-dimethyl-2-pyridones
ALEKSANDAR D. MARINKOVIC, NATASA V. VALENTIC, DUSAN Z. MIJIN, GORDANA G. USCUMLIC and BRATISLAV Z. JOVANOVIC

Department of Organic Chemistry, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, P. O. Box 3503, Serbia

(Received 24 July 2007, revised 22 January 2008)

The ¹³C- and ¹H-NMR chemical shifts of thirteen N(1)-(4-substituted phenyl)-3-cyano-4,6-dimethyl-2-pyridones were measured in deuterated dimethyl sulfoxide (DMSO-d₆). The correlation analysis for the substituent-induced chemical shifts (SCS) with s_p, inductive (s_I) and different scale of resonance (s_R) parAMeters were performed using the SSP (single substituent parAMeter), DSP (dual substituent parAMeter) and DSP–NLR (dual substituent parAMeter–non-linear resonance) methods. The results of the calculations concerning the polar and resonance effects satisfactorily describe the substituent effects at the carbon atoms of interest. The mode of transmission of the substituent effects, both inductive and resonance, in relation to the geometry of the investigated pyridones is discussed.

Keywords: ¹³C-NMR substituent chemical shifts; linear free energy relationships; N(1)-(4-substituted phenyl)-3-cyano-4,6-dimethyl-2-pyridones.

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J. Serb. Chem. Soc. 73 (5) 525–529 (2008)
UDC *Onobrychis scardica:543.422.25: 577.164.3:547.918; JSCS–3733; doi: 10.2298/JSC0805525G; Original scientific paper

Flavonoids from the aerial parts of Onobrychis montana subsp. scardica
DEJAN GODJEVAC, BORIS PEJIN*, GORDANA ZDUNIC**, KATARINA SAVIKIN**, DANIJELA STESEVIC***, VLATKA VAJS and SLOBODAN MILOSAVLJEVIC**
Institute of Chemistry, Technology and Metallurgy, Njegoseva 12, 11000 Belgrade, Serbia

*Faculty of Chemistry, Studentski trg 16, 11000 Belgrade, Serbia

**Institute for Medicinal Plant Research “Dr. Josif Pancic”, Tadeusa Koscuska , 11000 Belgrade, Serbia

***Biology Department, Faculty of Science, University of Montenegro, 81000 Podgorica, Montenegro

(Received 26 September, revised 27 December 2007)

Rutin (1, main constituent) and two flavone C-glycosides, vitexin (2) and vitexin 2''-O-a-rhAMnopyranoside (3) were isolated from the aerial parts of Onobrychis montana subsp. scardica. They were identified by ¹H-NMR, ¹³C-NMR and UV–Vis spectroscopy (procedure with shift reagents), and high resolution ESI-MS. A relatively high content of 1 (5.27 mg/g of dry plant material), measured by HPLC, indicated O. montana subsp. scardica as a new natural source of this biologically active compound. The isolated flavonoid compounds might be of value as chemotaxonomic markers.

Keywords: Onobrychis scardica; Fabaceae; flavonoids.

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J. Serb. Chem. Soc. 73 (5) 531–540 (2008)
UDC *Hieracium pilosella L.:633.879.6: 665.7.038.5:615.28; JSCS–3734; doi: 10.2298/JSC0805531S; Original scientific paper

Anti-oxidative and antimicrobial activities of Hieracium pilosella L. extracts
LJILJANA P. STANOJEVIC, MIHAJLO Z. STANKOVIC, VESNA D. NIKOLIC and LJUBISA B. NIKOLIC
Faculty of Technology, Bulevar Oslobodjenja 124, 16000 Leskovac, Serbia

(Received 28 June, revised 22 october 2007)

The anti-oxidative and antimicrobial activities of different extracts from Hieracium pilosella L. (Asteraceae) whole plant were investigated. The total dry extracts were determined for all the investigated solvents: methanol, dichloromethane, ethyl acetate and dichloromethane:methanol (9:1). It was found that the highest yield was obtained by extraction with methanol (12.9 g/100 g of dry plant material). Qualitative and quantitative analysis were performed by the HPLC method, using external standards. Chlorogenic acid, apigenin-7-O-glucoside and umbelliferone were detected in the highest quantity in the extracts. The qualitative and quantitative composition of the extracts depends on the solvent used. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of the extracts was determined spectrophotometrically. The highest radical scavenging effect was observed in the methanolic extract, both with and without incubation, EC₅₀ = 0.012 and EC₅₀ = 0.015 mg ml^-1, respectively. The antimicrobial activities of the extracts towards the bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Salmonella enteritidis and Klebsiella pneumoniae) and the fungi (Aspergillus niger and Candida albicans) were determined by the disc diffusion method. The minimal inhibitory concentrations were determined for all the investigated extracts against all the mentioned microorganisms.

Keywords: Hieracium pilosella L.; anti-oxidant activity; antimicrobial activity; HPLC determination.

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J. Serb. Chem. Soc. 73 (5) 541–545 (2008)
UDC 546.963'131+542.9+541.183.7+54–145.2:54–74; JSCS–3735; doi: 10.2298/JSC0805541G; Short communication

Short communication

Stereospecific ligands and their complexes.

Synthesis and characterization of the s-cis-K[Ru(S,S-eddp)Cl₂]∙3H₂O
VERICA V. GLODJOVIC and SRECKO R. TRIFUNOVIC
Department of Chemistry, Faculty of Science, University of Kragujevac, Radoja Domanovica 12, P. O. Box 60, 34000 Kragujevac, Serbia

(Received 2 August, revised 10 December 2007)

In the reaction of ruthenium(III) chloride and an edda-like ligand ethylenediAMine-N,N'-di-S,S-2-propionic acid (S,S-eddp) in aqueous solution led to the formation of only one of the three possible geometrical isomers potassium-s-cis-dichlorido-(ethylenediAMine-N,N'-di-S,S-2-propionato)-ruthenate(III)--trihydrate, s-cis-K[Ru(S,S-eddp)Cl₂]∙3H₂O. The assumed geometry of the complex was based on its electronic absorption and infrared spectra.

Keywords: ruthenium(III) complex; S,S-ethylenediAMine-N,N’-di-S,S-propionate ligand; electronic absorption and infrared spectra.

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J. Serb. Chem. Soc. 73 (5) 547–554 (2008)

UDC 539.124:534.24:547.235; JSCS–3736; doi: 10.2298/JSC0805547S; Original scientific paper

Partitioning of p-electrons in rings of diaza-derivatives of acenes

SONJA STANKOVIC, JELENA DJURDJEVIC, IVAN GUTMAN and RADMILA MILENTIJEVIC

Faculty of Science, University of Kragujevac, P. O. Box 60, 34000 Kragujevac, Serbia

(Received 17 December 2007)

A few years ago, a method was proposed for assessing the p-electron content (EC) of rings in heteroatom-containing benzenoid molecules. In this work, the effect of two nitrogen atoms at the opposite sides of a linear benzenoid molecule on the partitioning of its p-electrons was investigated. The results obtained can be explained by means of resonance-theoretical arguments.

Keywords: partitioning of p-electrons in rings; p-electron content of ring; aza-derivatives of acenes; resonance theory.

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J. Serb. Chem. Soc. 73 (5) 555–560 (2008)

UDC 546.289'161+546.28'161:531.64:517.956.2; JSCS–3737; doi: 10.2298/JSC0805555K; Original scientific paper

Franck–Condon factors and r-centroids for the diatomic fluorides of germanium and silicon

S. KANAGAPRABHA, R. RAJESWARA PALANICHAMY and V. SATHIYABAMA

Department of Physics, N. M. S. S. V. N College, Madurai – 625 019, TAMilnadu, India

(Received 7 November 2006, revised 9 February 2007)

A suitable potential energy function was found by analysing the potential functions proposed by Morse, MohAMmad and Rafi et al. for the A²Σ⁺–X²Π_3/2and B²Σ⁺–X²Π_3/2 band systems of GeF and the ¹Σ–¹Π band system of SiF. It was found that the potential proposed by Rafi et al. is in close agreement with the Rydberg–Klein–Rees (R–K–R) potential. Using this potential, the wave functions were evaluated by the Wentzel–KrAMer–Brillouin (W–K–B) method. The Franck–Condon factors and r-centroids were computed by a numerical integration technique. The results are compared with available theoretical values. The intensities of the various bands were investigated.

Keywords: Franck–Condon factor; r-centroid; potential function; GeF and SiF.

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J. Serb. Chem. Soc. 73 (5) 561–568 (2008)

UDC 778.38+77.035:546.62+546.131–71; JSCS–3738; doi: 10.2298/JSC0805561L; Original scientific paper

Investigation of the pitting of aluminum induced by chloride ions by holographic microphotography

LIANG LI*, CHAO WANG*^,***, SHENHAO CHEN**^,***, XIANMIN HOU** and XUEGENG YANG**

*Department of Chemistry, Xuzhou Normal University, Xuzhou 221009, P. R. China

**Department of Chemistry, Shandong University, Jinan 250100, P. R. China

***State Key Laboratory for Corrosion and Protection, Shenyang 110016, P. R. China

(Received 29 October 2007, revised 7 January 2008)

Holographic microphotography was used to investigate the dynAMic processes of pitting during anodic dissolution of aluminum in a solution containing chloride ions. The induction and the follow-up propagation processes of the pitting were observed in real-time. A simple model of the propagating process of the pitting was deduced from the result of the hologrAMs of the Al/electrolyte interface. The results prove that holographic microphotography is a useful tool to study the dynAMic processes of pitting.

Keywords: holography; pitting; aluminum; chloride ions.

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J. Serb. Chem. Soc. 73 (5) 569–576 (2008)

UDC 615.33+615.276+546.723:66.094.3:543.4/.5; JSCS–3739; doi: 10.2298/JSC0805569I; Original scientific paper

An indirect atomic absorption spectrometric determination of ciprofloxacin, AMoxycillin and diclofenac sodium in pharmaceutical formulations

MAHMOUD MOHAMED ISSA, R’AFAT MAHMOUD NEJEM, MONZER AL-KHOLY, NASER SAID EL-ABADLA*, RAFIK SOBHI HELLES and AKILA AMIN SALEH**

Analytical Chemistry, Department of Chemistry, Alaqsa University, P. O. Box 4051, Gaza, Palestine

*Organic Chemistry, Department of Chemistry, Alaqsa University, Gaza, Palestine

**Analytical Chemistry, Ain ShAMs University, Cairo, Egypt

(Received 23 May, revised 7 December 2007)

A highly sensitive indirect atomic absorption spectrophotometric (AAS) method has been developed for the determination of very low concentrations of ciprofloxacin, AMoxycillin and diclofenac sodium. The method is based on the oxidation of these drugs with iron(III). The excess of iron(III) was extracted into diethyl ether and then the iron(II) in the aqueous layer was aspirated into an air–acetylene flAMe and determined by AAS. The linear concentration ranges were 25–400, 50–500 and 60–600 ng ml^-1 for ciprofloxacin, AMoxycillin and diclofenac sodium, respectively. The results were statistically compared with the official method using t- and f-test at p < 0.05. There were insignificant interferences from most of the excipients present. The intra- and inter-day assay coefficients of variation were less than 6.1 % and the recoveries ranged from 95 to 103 %. The method was applied for the analysis of these drug substances in their commercial pharmaceutical formulations.

Keywords: ciprofloxacin; AMoxycillin; diclofenac sodium; indirect atomic absorption spectrometry.

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J. Serb. Chem. Soc. 73 (5) 577–583 (2008)

UDC 628.193:665.62:547.21+665.12; JSCS–3740, doi: 10.2298/JSC0805577J; Original scientific paper

Transformation of a petroleum pollutant during soil bioremediation experiments

B. JOVANCICEVIC*^,**, M. ANTIC***, M. VRVIC*^,**, M. ILIC**, M. NOVAKOVIC*, R. M. SAHEED* and J. SCHWARZBAUER****

*Department of Chemistry, University of Belgrade, Studentski trg 12–16, 11001 Belgrade, Serbia

**Centre of Chemistry, ICTM, Belgrade, Serbia

***Department of Agriculture, University of Belgrade, Belgrade, Serbia

****Institute of Geology and Geochemistry of Petroleum and Coal, Aachen University, Aachen, Germany

(Received 24 October 2007)

The experiment of ex situ soil bioremediation was performed at the locality of the Oil Refinery in Pančevo (alluvial formation of the Danube River, Serbia) polluted with an oil type pollutant. The experiments of biostimulation, bioventilation and reinoculation of an autochthonous microbial consortium were performed during the six-month period (May–November 2006). The changes in the quantity and composition of the pollutant, or the bioremediation effect, were monitored by analysis of the sAMples of the polluted soil taken in time spans of two weeks. In this way, from the beginning until the end of the experiment, 12 sAMples were collected and marked as P₁–P₁₂ (Pančevo 1–Pančevo 12). The results obtained showed that more significant changes in the composition of the oil pollutant occurred only during the last phases of the experiment (P₈–P₁₂). The activity of microorganisms was reflected in the increase of the quantity of polar oil fractions, mainly fatty acid fractions. In this way, the quantity of total eluate increased, and the quantity of the insoluble residue was reduced to a minimum, whereby the oil pollutant was transformed to a form that could be removed more efficiently and more completely from the soil, as a segment of the environment.

Keywords: bioremediation; oil type pollutant; soil; Pančevo Oil Refinery; alkanes; fatty acids.

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J. Serb. Chem. Soc. 73 (5) 585–593 (2008)

UDC 669.22+669.4:622.234.4+669.53; JSCS–3741; doi: 10.2298/JSC0805585S; Original scientific paper

Lead and silver extraction from waste cake from hydrometallurgical zinc production

DUSAN D. STANOJEVIC, MILOS B. RAJKOVIC*, DRAGAN V. TOSKOVIC and MILANA A. TOMIC**

Faculty of Technology, University of East Sarajevo, Karakaj b.b., 76000 Zvornik, Republic of Srpska, Bosnia and Herzegovina

*Institute of Food Technology and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Zemun, Serbia

**Higher Technological School of Professional Studies in Sabac, H. Veljkova 10, 15000 Sabac, Serbia

(Received 30 October, revised 7 December 2007)

This paper presents the experimental results of the extraction of lead and silver from a lead–silver waste cake obtained in the process of hydrometallurgical zinc production. While controlling the pH value, the lead–silver cake was leached at a temperature close to boiling point in different concentrations of aqueous calcium chloride solutions. The experiments were performed applying different ratios between the mass of cake and the volume of the leaching agent under different durations of the process. It was concluded that at the optimal process parAMeters (pH 2.0–2.5; CaCl₂ concentration, 3.6 mol dm^-3; temperature, 95 °C; solid/liquid ratio, 1:5), the leaching efficiency of lead and silver could reach the approximate value of 94 %. Applying the sAMe optimal process parAMeters, the method was applied to the leaching of a lead–silver cake in a magnesium chloride solution, but with significantly lower efficiencies. The results show that leaching of lead and silver in a calcium chloride solution could be a prospective method for increasing the recovery of lead and silver during hydrometallurgical zinc production.

Keywords: lead–silver cake; chloride solutions; leaching; metal recovery.

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J. Serb. Chem. Soc. 73 (5) 595 (2008)

Errata

Errata

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