JSCS Vol 73, No. 2
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J. Serb. Chem. Soc. 73 (2) 131–138 (2008)
UDC 547.78+542.913:547.334:547.77; JSCS–3695; doi: 10.2298/JSC0802131K; Original scientific paper
Expeditious synthesis of 1,3,4-oxadiazole derivatives
via sydnones
RAVINDRA R. KAMBLE, B. S. SUDHA and D. G. BHADREGOWDA
Department of Chemistry and Food Science, Yuvaraja’s
College, University of Mysore, Mysore – 570 005, India
(Received 21 June, revised
The clean cyclization of chalcones (1a–c/2a–c) with
hydrazine hydrate under microwave irradiation afforded pyrazolines derivatised
with sydnone (3d–i/4d–i), which underwent 1,3-dipolar cyclo-addition with
acetic anhydride to form pyrazolines appended with 1,3,4-oxadiazoles
(5g–l/6g–l). The newly synthesized compounds were confirmed by spectral and
elemental analyses. In comparison to classical heating, the results indicate
that microwave irradiation affords higher yields, shorter reaction times (4–12
min) and cleaner reactions.
Keywords: porphyrin microwave irradiation; sydnones; chalcones;
pyrazolines; 1,3,4-oxadiazoles.
Full Article - PDF 332 KB
J. Serb. Chem. Soc. 73 (2) 139–145 (2008)
UDC 662.237.3:66–95:579.23:579.67;
JSCS–3696; doi: 10.2298/JSC0802139S;
Original scientific paper
Recombinant expression of monovalent and bivalent
anti-TNT-antibodies – evaluation of different expression systems
MLADEN SIMONOVIC, SVETLANA ZLATANOVIC-MILOSEVIC*, MIROSLAV M. VRVIC** and
BRANISLAV SIMONOVIC
Institute for General and Physical Chemistry, Studentski trg 12–16, 11000
Belgrade, Serbia
*Faculty of Mathematics and Natural Sciences,
**Faculty of Chemistry, University of Belgrade,
Studentski trg 12–16, 11000
(Received 7 February, revised 2 July
2007)
Monoclonal 11B3 anti-TNT (trinitrotoluene) antibody
was expressed as a monovalent and bivalent form using different prokaryotic and
eukaryotic expression systems. Recombinant expression in Escherichia coli, mAMmalian cells and the methylotrophic yeast Pichia pastoris was performed to obtain
disulfide-linked and glycosylated antibody forms. The generation of antibody
and subsequent evaluation of the expression rates were performed using
intracellular, excretory and periplasmatic expression techniques. All methods
involved striving for native expressed antibody with maintenance of its
functionality only.
Keywords: TNT; antibody; recombinant expression; 11B3; scFv.
Full Article - PDF 374 KB
J. Serb.
Chem. Soc. 73 (2) 147–156 (2008)
UDC 66.011+665.75.000.57.002.2:577.15;
JSCS–3697; doi: 10.2298/JSC0802147O; Original scientific paper
Optimization of the production of
biodiesel by a commercial immobilized lipase in a solvent-free system using a
response surface methodology
NEVENA OGNJANOVIC, DEJAN BEZBRADICA and ZORICA KNEZEVIC
Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade, Serbia
(Received 14 March, revised 2 July 2007)
Response
surface methodology was used for the evaluation of the effects of various factors
on the synthesis of biodiesel catalyzed with immobilized lipase from Rhizomucor miehei in a solvent-free
system. The production of biodiesel was optimized and model response equations
were obtained, enabling the prediction of biodiesel production from the values
of the four main factors. It would seem that the reaction temperature and the
AMount of water predominantly determined the conversion process while the
methanol/oil molar ratio had no significant influence on the reaction rate. The
temperature and AMount of water showed negative interactive effects on the
observed reaction rate per AMount of enzyme. However, there were no significant
interactions AMong the other variables according to the test of statistical
significance. The highest yield of 10.15 mol kg-1 enzyme was
observed at 45 °C with a 6:1 methanol to oil molar ratio and with no added
water in the system.
Keywords:
lipases from Rhizomucor miehei;
biodiesel; response surface methodology.
Full Article - PDF 725 KB
J. Serb. Chem. Soc. 73 (2) 157–167 (2008)
UDC 542.92:664.29+582.734.3; JSCS–3698; doi:
10.2298/JSC0802157N;
Original scientific paper
Characterization and degradation of
pectin derived from Budimka apple
MILOS V. NIKOLIC and LJILJANA MOJOVIC*
"Srbijanka" Food-Processing Industry, 14 000 Valjevo,
*Faculty of Technology and Metallurgy, Department of
Biochemical Engineering and Biotechnology University of Belgrade, Karnegijeva
4, 11000 Belgrade, Serbia
(Received 26 February, revised 1 August
2007)
The characterization of apple pectin and its oligogalacturonic
fractions derived from the autochthones apple variety Budimka, characteristic
for central Serbia, is described in this paper. After extraction, the apple
pectin was subjected to controlled enzymatic hydrolysis by polygalacturonase
(PG) and pectin lyase (PL) from Aspergillus
niger and then fractionated by ion-exchange column chromatography on Dowex
1X-8 (200–400 mesh). Saturated oligogalacturonic acids, obtained by controlled
hydrolysis with PG, were efficiently separated by elution with a gradient of Na
acetate buffer (pH 6.0), while unsaturated oligogalacturonic acids, obtained by
controlled hydrolysis with PL, were separated on the sAMe resin, using a
gradient of Na formate buffer (pH 4.7) as the eluent. The yields of the
fractions with the particular degree of polymerization (DP) were also determined. The total content of neutral saccharides
in the original Budimka apple pectin was detected by HPLC analysis of the
4-nitrobenzoyl derivatives of the sugar, and AMounted to 5.31 %. Among the
neutral saccharides, contents of galactose, glucose, rhAMnose, arabinose,
xylose and mannose were detected.
Keywords: synergistic degradation; fractionation;
oligogalacturonic acids; Budimka apple pectin; polygalacturonase; pectin lyase;
neutral saccharides.
Full Article - PDF 445 KB
UDC
546.742+547.466+547.496.2:543.4:543.57; JSCS–3699; doi: 10.2298/JSC0802169G; Original scientific paper
Characterization studies and cyclic voltAMmetry on
nickel(II) AMino acid dithiocarbAMates with triphenylphosphine in the
coordination sphere
NATESAN GEETHA
and SUBBIAH THIRUMARAN
Department of
Chemistry, AnnAMalai University, AnnAMalainagar – 608 002,
(Received 18 January, revised 10 July 2007)
Nickel(II) AMino acid dithiocarbAMate
complexes of the composition [Ni(AAdtc)(PPh3)(NCS)], [Ni(AAdtc)(PPh3)(CN)]
and [Ni(AAdtc)(PPh3)2]ClO4 [(AAdtc =
dithiocarbAMate derivatives of AMino acids, i.e., glycine (glydtc), L-iso-leucine
(i-leudtc) and L-proline (prodtc)] were synthesized. The compounds were
characterized by IR and electronic spectroscopy, thermal analysis, cyclic
voltAMmetry and conductivity measurements. In the case of the mixed ligand
complexes, the thioureide n(C−N) values were shifted to higher wave numbers
compared to [Ni(AAdtc)2]. This observation shows the increased
strength of the thioureide bond due to the presence of the p-accepting phosphine.
Electronic spectral studies suggest square planar geometry for the complexes.
Thermal analyses of the complexes are in keeping with the proposed formulae.
Almost all the complexes showed signs of decay above 170 °C. At around 390 °C,
the final mass corresponded to NiS. Cyclic voltAMmetry showed a decrease of the
electron density on the nickel in the mixed ligand complexes compared to
[Ni(AAdtc)2].
Keywords:
AMino acid dithiocarbAMate; triphenylphosphine; nickel(II); IR; electronic
spectra; cyclic voltAMmetry.
Full Article - PDF 376 KB
UDC *Organotin(IV)+547.595:542.913; JSCS–3700; doi:
10.2298/JSC0802179H; Original scientific paper
Synthesis and structural characterization of organotin(IV) complexes
formed with [O,O] donor atoms of carboxylic acids
MUKHTIAR HUSSAIN, MUHAMMAD ZAMAN, MUHAMMAD HANIF,
SAQIB ALI and MUHAMMAD DANISH*
Department of Chemistry,
Quaid-i-AzAM University, IslAMabad–45320,
*Department of Chemistry,
University of Sargodha,
(Received 14 May, revised 22 October 2007)
Organotin(IV) carboxylates of the general
formula RnSnL4-n (where R = Me, n-Bu or Ph, and L = a-phenyl-2,3-(methylenedioxy)cinnAMate anion
or 2-(2,3-dimethlylanilino)nicotinate anion) have been prepared. The mono-, di-
and tri-organotin(IV) carboxylates were synthesized by the reaction of
organotin(IV) oxides or hydroxides with a stoichiometric AMount of the ligand
acids at an elevated temperature in dry toluene. The composition of the
synthesized organotin(IV) complexes, the bonding behavior of the donor groups
and structural assignments were studied by elemental analysis, FT-IR, 1H-,
13C-NMR and mass spectrometry. The spectral data suggest that the
ligand acts in a bidentate manner, coordinating through the oxygen atoms. These
spectroscopic techniques revealed a distorted tetrahedral geometry in the
solution state for the tri-organotins, while a mean coordination number between
five to six for the di-organotin(IV) dicarboxylates. In the solid phase, the
tri-organotins were essentially trigonal bipyrAMidal polymeric while the
di-organotins were octahedral. However, mono-organotin tricarboxylates were predicted
to exist in the octahedral state both in solution as well as in the solid
phase.
Keywords: organotin(IV)
complexes; O-donor ligands; IR, NMR and mass spectrometry.
Full Article - PDF 262 KB
J. Serb. Chem. Soc. 73 (2) 189–195 (2008)
UDC 519.17:547.233’237+546.922:547.97; JSCS–3701; doi: 10.2298/JSC0802189M; Original
scientific paper
Q-Conjugacy character and Markaracter
tables of tetraAMmineplatinum(II)
ALI MOGHANI
Department of
Color Physics, Institute for Colorants, Paints and Coatings (ICPC),
(Received 7 May, revised 8 June 2007)
The Q-conjugacy character and Markaracter
tables of finite groups were introduced by Fujita, who applied his results in
this area of research to enumerate isomers of molecules. In this paper, these
tables are computed for tetraAMmineplatinum(II).
Keywords: Franck–Condon factors; r-centroids and isotopic molecule SbO and SbP molecules.
Full Article - PDF 508 KB
J. Serb. Chem. Soc. 73 (2)
197–209 (2008)
UDC 546–328+54–145.2:543.422.25; JSCS–3702; doi:
10.2298/JSC0802197B; Original scientific paper
A study of 12-tungstosilicic
and 12-molybdophosphoric acids in solution
Faculty of Physical
Chemistry, P.O. Box 47, 11158 Belgrade 118,
*Faculty of Chemistry, P.O.
Box 157, 11001
**Institute of General and
Physical Chemistry, P.O. Box 551, 11001
(Received 21 February, revised 19 September 2007)
The behaviour of two heteropolyacids (HPAs) with quite different
stability in aqueous solutions was systematically investigated by UV, IR and
NMR spectroscopy and potentiometric titration. It was shown that the Keggin
structure of 12-tungstosilicic acid (H4SiW12O40,
WSiA) anion was sustained over a wide range of pH from 1.0 to 7.0, while the
sAMe anion type of 12-molybdophosphoric acid (H3PMo12O40,
MoPA) was present only at pH 1.0. This means that under physiological
conditions WSiA is dominantly present in the form of a Keggin-anion, whereas
the structure of MoPA is completely decomposed to molybdate and phosphate. The
obtained results are of special importance for bio-medical and catalytic
applications of these compounds and for a better understanding of the mechanism
of their action.
Keywords: heteropolyacids of Keggin structure;
12-tungstosilicic acid; 12-molybdophosphoric acid; hydro-stability; UV; IR and
NMR spectroscopy.
Full Article - PDF 352 KB
J. Serb. Chem. Soc. 73 (2)
211–219 (2008)
UDC
546.74’22+66.094.3:531.3+541.124; JSCS–3703, doi:
10.2298/JSC0802211S; Original scientific paper
Mechanism and kinetics of the
oxidation of synthetic a-NiS
NADA STRBAC, DRAGANA
ZIVKOVIC, IVAN MIHAJLOVIC, BOYAN BOYANOV* and ZIVAN ZIVKOVIC
University of Belgrade,
Technical Faculty, Vojske Jugoslavije 12, Bor, Serbia
*University “Paisiy
Hilendarsky”, Tsar Assen 24, 4000
(Received 29 March, revised
4 September 2007)
The results of an
investigation of the mechanism and kinetics of the oxidation process of
synthetic a-NiS are
presented in this paper. The mechanism of a-NiS oxidation was
investigated based on the comparative analysis of DTA–TG–DTG and XRD results,
as well as the constructed phase stability diagrAMs (PSD) for the Ni–S–O
system. The kinetic investigations of the oxidation process were performed
under isothermal conditions (temperature range 823–1073 K). The obtained
degrees of desulfurization were used in the calculation process according to
the Sharp model and the kinetic parAMeters, including the activation energies
and the rate constants of the characteristic reactions, for the oxidation of a-NiS were determined. These
results enabled the formulation of a kinetic equation for the desulfurization
process: ‑ln(1−a) = k1t = 27.89 exp(–9860/T)t, with an activation energy
of 82±4 kJ mol-1, for the first stage of the process and –ln (1 − a) = k2t = 1.177 exp(–4810/T)t, with an activation energy
of 40±2 kJ mol-1, for the second stage.
Keywords: anti-inflAMmatory agents; potentiometric
titration; artificial neural network (ANN).
Full Article - PDF 287 KB
J. Serb. Chem. Soc. 73 (2)
221–226 (2008)
UDC 546.47+546.175–323+544.35:66.082.2:620.193;
JSCS–3704; doi: 10.2298/JSC0802221C; Original scientific paper
Periodic current
oscillations of zinc in nitric acid solutions
FLORIN CRISAN and ERVIN
SALLÓ*
County Lab for Pesticides
Quality Control, Bodrogului Str. 3, 310059,
*Chemistry Institute of
Romanian Academy, Mihai Viteazul Blvd. 24, 300223, Timisoara, Romania
(Received 22 September
2006, revised 13 June 2007)
The charge percolation
mechanism (CPM) of olefin polymerization in the presence of transition metal
compounds has been applied to explain the polymerization of ethylene by silica
supported chromium oxide. In the previous work of this series, the fundAMental
issues and mechanism of this polymerization were presented. In this work the compatibility
of the CPM with the empirical findings is confirmed. The CPM has been applied
to explain: the appearance of an induction period; the deactivation of active
centers and the formation of oligomers; the effects of chromium concentration
on the silica surface, the silica surface discontinuity and the pore size of
silica on polymerization and the formation of the structure of polyethylene. A
mathematical model has been derived to explain the effects of the CrOx/SiO2
ratio on the productivity of Phillips catalysts in the polymerization of
ethylene. The empirical findings have also been confirmed by computer
simulations.
Keywords: ethylene polymerization; Phillips CrOx/SiO2;
charge percolation mechanism.
Full Article - PDF 248 KB
J. Serb. Chem. Soc. 73 (2) 227–231
(2008)
UDC 535.513+512.77+517968.2:541.138–034:681.5.017;
JSCS–3705; doi: 10.2298/JSC0802227Z; Note
NOTE
The validity of
the general polarization curve equation approximation for the process of metal
deposition
PREDRAG M. ZIVKOVIC,
BRANIMIR N. GRGUR and KONSTANTIN I. POPOV
Faculty of Technology and
Metallurgy, University of Belgrade, Karnegijeva 4, 11120
(Received 15 June, revised
Digital simulation was
employed for the solution of the general polarization curve equation of metal deposition
processes. By approximating the dependence of the exchange current density on
concentration with a linear function for one- and two-electron transfer
processes, an error lower than 20 % was obtained.
Keywords: polarization curve equation; metal deposition;
exchange current density; simulation.
Full Article - PDF 304 KB
J. Serb. Chem. Soc. 73 (2)
233–247 (2008)
UDC
547.869+615.32:543.4/.5; JSCS–3706; doi: 10.2298/JSC0802233K; Original scientific paper
Individual and
simultaneous determinations of phenothiazine drugs using PCR, PLS and (OSC)–PLS
multivariate calibration methods
MOHAMMAD ALI KARIMI*,**,***,
MOHAMMAD MAZLOUM ARDAKANI****, REZA BEHJATMANESH-ARDAKANI**, MOHAMMAD REZA
HORMOZI NEZHAD***** and HAMZEH AMIRYAN**
*Department of Chemistry, PayAMe
Noor University of Sirjan,
**Department of Chemistry,
PayAMe Noor University of Ardakan,
***Department of Chemistry,
Shahid Bahonar University of Kerman,
****Department of
Chemistry, Yazd University,
*****Department of
Chemistry, Persian Gulf University,
(Received 14 September
2006, revised 24 July 2007)
Individual and simultaneous
determinations of some phenothiazine drugs are described. The individual determination
method is based on the reaction of chlorpromazine hydrochloride (CPH),
promethazine hydrochloride (PH), trifluoperazine hydrochloride (TFPH),
trimiprAMine maleate (TPM) and thioridazine hydrochloride (TRDH) with complex
of [Fe(Bpy)3]3+. In the presence of phenothiazine
derivatives, [Fe(Bpy)3]3+ is reduced easily to the
coloured complex [Fe(Bpy)3]2+, which shows an absorption
maximum at 525 nm. The individual method is highly sensitive and suitable for
0.3–190 mg ml-1
concentrations, with detection limits in the range 0.18–2.46 mg ml-1.
Simultaneous kinetic–spectrophotometric determination of ternary mixture of
CPH, PH and TPM using principal component regression (PCR), partial least
squares (PLS) and orthogonal signal correction (OSC)–PLS multivariate
calibration methods is also described. The simultaneous methods are based on
the difference observed in the reduction rate of the [Fe(Bpy)3]3+
complex with CPH, PH and TPM in acidic media. The results showed that the
simultaneous determination of CPH, PH and TPM can be performed in the
concentration ranges of 0.5–120.0, 0.3–80.0 and 5.0–100.0 µg ml-1,
respectively, for three methods (PCR, PLS and OSC–PLS). The root mean square
errors of prediction (RMSEP) of CPH, PH and TPM were 0.346, 0.663 and 0.820
(for PCR) 0.317, 0.659 and 0.830 (for PLS) and 0.087, 0.124 and 0.085 (for
OSC–PLS), respectively. The proposed methods were successfully applied to the
individual and simultaneous determination of phenothiazine derivatives in
pharmaceutical preparations, the results of which compared well with those
obtained by the official method, and several synthetic (spiked) sAMples,
whereby satisfactory results were obtained.
Keywords: individual and simultaneous determinations;
phenothiazine drugs; PLS; PCR; OSC–PLS.
Full Article - PDF 349 KB
J. Serb. Chem. Soc. 73 (2)
249–258 (2008)
UDC
546.56+54–145.2+546.185–323:543.42+543:541.183; JSCS–3707; doi:
10.2298/JSC0802249G; Original scientific paper
Determination of
trace copper in water sAMples by flAMe atomic absorption spectrometry after
preconcentration on a phosphoric acid functionalized cotton chelator
RENMIN GONG, DEMIN ZHANG,
KEDING ZHONG, MIN FENG and XINGYAN LIU
The Laboratory of
Bio-Macromolecular Evolution, College of Life Science, Anhui Normal University,
Wuhu, 241000, P. R. China
(Received 20 February,
revised 8 August 2007)
This paper reports the
preparation of a phosphorylated cotton chelator (PCC) by solid phase
esterification of phosphoric acid (PA) onto defatted cotton fibres using urea
as the catalyst. The synthesized PCC was employed for the preconcentration of
copper from water sAMples prior to its determination by flAMe atomic absorption
spectrometry (FAAS). The preconcentration of copper was studied under both
batch and column techniques. The pH range for the quantitative preconcentration
of copper was 4.0–7.0. The sorption time required for each sAMple was less than
30 min by the batch method. The copper sorption capacity of the PCC was found
to be 15.3 mg/g at the optimum pH value. Elution with 1.0 mol dm-3 hydrochloric
acid was found to be quantitative. Feasible flow rates of the copper solution
for quantitative sorption onto the column packed with PCC were 0.5–4.0 ml min-1,
whereas the optimum flow rate of the hydrochloric acid solution for desorption
was less than 1.5 ml min-1. An 80-fold preconcentration factor could
be achieved under the optimum column conditions. The tolerance limits for
common metal ions on the preconcentration of copper and the number of times of
column reuse were investigated. The proposed method was successfully applied
for the preconcentration and determination of trace copper in natural and
drinking water sAMples by FAAS.
Keywords: phosphoric acid; PCC; trace copper;
preconcentration; FAAS; determination.
Full Article - PDF 253 KB
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