J. Serb. Chem. Soc. 61(12) 1117-1125 (1996)
UDC 547.822.3/.823:539.12-1
JSCS-2333
Original scientific paper
Conformational study of fentanyl and its analogs. 3.
Conformational space and electronic properties of carfentanil,
3-carbomethoxy fentanyl and CH-fentanyl
Lj. DOŠEN-MICOVIC and
I. V. MICOVIC
Faculty of Chemistry, University of Belgrade, Studentski trg 16, P.O.Box 158, YU-11000 Belgrade,
Yugoslavia and
Institute of Chemistry, Technology and Metallurgy
(ICTM) - Center for Chemistry, University of Belgrade, YU-11000 Belgrade,
Yugoslavia
(Received
14 July 1996)
The conformational space and electronic properties of
the CH-fentanyl, a postulated antagonist of the fentanyl class of opiates, have
been investigated by molecular mechanics (MM2) and quantum mechanics (PM3)
methods. It has been found that reduced proton affinity of the amide oxygen (i.e.,
reduced electron density in this region) might be the major reason for the
reduced activity of CH-fentanyl compared to fentanyl. Carfentanil
and 3-carbo-methoxy fentanyl have also been studied in order to determine the
location requirements for the high electron density region, which is believed
to be one of the modulators of receptor activation.
Key words: fentanyl analogs, 3-carbomethoxy fentanyl, molecular
mechanics, molecular modeling, structure-activity relationship.
J. Serb. Chem. Soc.
61(12) 1127-1135 (1996)
UDC 547.514.72
JSCS-2334
Original scientific paper
Studies of
ferrocene derivatives. III. High resolution NMR spectra of erythro
and threo 1,1'-bis(1-hydroxy-1-methylalkyl)ferrocenes
STANIMIR KONSTANTINOVIC, SVETLANA SIMOVA*, ANNA RUFINSKA**, ZORAN RATKOVIC,
JASMINA PREDOJEVIC and MILOŠ DJURAN
Department of Chemistry, Faculty of Science,
University of Kragujevac, P.O. Box 60, YU-34000 Kragujevac, Yugoslavia,
*Institute of Organic Chemistry, Bulgarian Academy of
Sciences, 1113 Sofia, Bulgaria and
**Max-Planck-Institut fur Kohlenforschung, Kaiser-Wilhelm-Platz 1
D-45470 Mulheim a.d. Ruhr,
F.R.G.
(Received
11 April, revised 19 september 1996)
Erythro and threo
1,1'-bis(1-hydroxy-1-methylalkyl)ferrocenes were synthesised
and their high resolution 1H and 13C-NMR
spectra were studied as a function of the stereochemistry of the substituents
connected to the cyclopentadienyl ring. It was found that when erythro and threo
1,1'-bis(1-hydroxy-1-methylalkyl)ferrocene contain a chiral center in the substitutent, the 2,5-and 3,4-positions in the
cyclopentadienyl ring became pairwise diastereotopic
and magnetically unequal. Through their high resolution 1H and 13C-NMR spectra the diastereoisomers mentioned
above could be identified and differentiated.
Key words: erythro and threo
1,1'-bis(1-hydroxy-1-methylalkyl)-ferrocenes, 1H and 13C-NMR spectra.
J. Serb. Chem. Soc.
61(12) 1137-1144 (1996)
UDC 547.586.2:547.298.1:68.095.25
JSCS-2335
Original scientific paper
Alkylation of N-ethyl-2-phenylacetamide
with benzyl halides
DUAN Z. MIJIN, BILJANA M. BOZIC, NADEZDA D. STOJANOVIC
and SLOBODAN D. PETROVIC
Faculty of Technology and Metallurgy, University of
Belgrade, Karnegijeva 4, P.O.Box
494, YU-11001 Belgrade, Yugoslavia
(Received
26 March, revised 9 September 1996)
Alkylations of N-ethyl-2-phenylacetamide with benzyl halides (chloride,
bromide and iodide) in the presence of powdered KOH were carried out in order
to establish the possible reaction products as well as to ascertain optimal
reaction conditions for the synthesis of different products. Reactions were
carried out in the presence of different phase-transfer catalysts, solvents and
temperatures. N-, O-, C- and C,N-products of
alkylation were established. Non-polar solvents were found to be the best for
this type of reaction.
Key words: Alkylation,
N-alkylation, C-alkylation, C,N-alkylation,
mono-N-substituted phenylacetamides, phenylacetamides, phase-transfer catalysis.
J. Serb. Chem. Soc. 61(12) 1145-1147 (1996)
UDC 547.543.2
JSCS-2336
Original scientific paper
Nucleophilic opening
of 1,3-2,5-DL-dianhydro xylitol system
SMILJANA VELIMIROVIC, JANOS CSANADI, EVGENIJA DJURENDIC and DUŠAN
MILJKOVIC
Institute of Chemistry, Faculty of Science, University
of Novi Sad, Trg Dositeja Obradovica 3, YU-21000 Novi Sad, Yugoslavia
(Received
25 September 1995, revised 7 August 1996)
The nucleophilic opening of the bicyclic derivatives
of 1,3-2,5-dianhydro-xylitol 4 and 5 with 1,2'-ethylene- and
1,3'-propylene-glycol, under base-catalyzed conditions, afforded
1-O-(2'-hydroxyethyl)- and 1-O-(3'-hydroxypropyl) derivatives of
2,5-anhydro-xylitol 6 and 7. The benzoylation of compounds 6
and 7 with benzoyl chloride in pyridine gave the corresponding perbenzoylated derivatives 8 and 9. In
addition, it was also found that the corresponding monoanhydro
precursors, namely, 1-O-p-toluenesulphonyl- and
l-chloro-1-deoxy-2,5-anhydro-xylitols 2 and 3, can be transformed
directly to target compounds 8 and 9, without isolating
intermediately formed oxetanes 4 and 5.
Key words: 2,5-anhydro-xylitol,
tosylation, benzoylation, oxetane system.
J. Serb. Chem. Soc.
61(12) 1149-1157 (1996)
UDC 615.25/.252:543.52/.53
JSCS-2337
Original scientific paper
Determination of
insulin-like growth factor-I by radioimmunoassay J.
ANNA NIKOLIC, MARIJA RATKOVIC and OLGICA NEDIĆ
INEP, Institute for the Application of Nuclear Energy,
Banatska 31B, YU-11080, Belgrade-Zemun,
Yugoslavia
(Received
13 February 1996)
A competitive binding assay for insulin-like growth
factor I (IGF-I) was set up using rabbit anti-human IGF-I antibodies as the
reagent and radioactively labelled recombinant human IGF-I as the tracer.
Displacement curves within the range of 0.3 to 90 µg IGF-I/L were obtained and
the radioimmunoassay standardised against a reference
preparation of IGF-I (WHO 87/518). Since the presence of binding proteins
affects the determination of IGF-I in biological samples, the effect of four
different extraction treatments developed for particular types of samples on
the validity of total IGF-I determinations was examined. Three treatments were
shown to be inadequate for porcine sera due to low or spuriously high
recoveries of added IGF-I resulting from the incomplete removal of binding
proteins. Acid ethanol extraction of porcine, bovine and human sera and tissue
extracts followed by neutralisation and cryoprecipitation provided a supernatant from which 99.6+17.1%
of added IGF-I was recovered. Dilution curves of sample extracts were parallel
to that of reference IGF-I and the precision of measurement was +4.95%
for four separate extracts of pooled human serum. It is suggested that a
critical factor for accurate determination of IGF-I by the adopted procedure
may be the use of polyethylene glycol assisted second antibody precipitation of
antigen-antibody complexes to separate free and bound fractions.
Key words: IGF - I, radioimmunoassay, somatomedin-C.
J. Serb. Chem. Soc.
61(12) 1159-1163 (1996)
UDC 581.1/.2:66.094.3-0978:543.866
JSCS-2338
Original scientific paper
Contribution to
the studies of plant antioxidants
D. MILADINOVIC, S. NAJMAN,* I. DJUJIC,** N. RANDJELOVIC*** and O. GAŠIC****
Department of Chemistry and
*Department of Biology, Faculty of Medicine, B. Taskovic 81, YU-18000 Ni,
**Center for Chemistry, Institute of Chemistry,
Technology and Metallurgy,
Njegoeva 12, YU-11000 Belgrade,
***Faculty of Technology, Durmitorska
19, YU-16000 Leskovac and
****Institute of Chemistry, Faculty of Science, Trg Dositeja Obradovica
3,
YU-21000 Novi Sad, Yugoslavia
(Received
4 October 1995, revised 2 July 1996)
Changes in the content of the total flavonoids of Astragalus
onobrychis Var. Chlorocarpus
(Gris.) Stoj. et Stef. (Leguminosae), during the
vegetation period have been studied. Some enzymes [superoxide dismutase (SOD),
peroxidase (P) and glutathione peroxidase (GSH-Px)]
have been surveyed. Finally, the degree of antioxidant activity of the plant
extract has been assessed by chemiluminiscence
kinetic assay (CL). The flavonoid content was not high (0.07 µg percent
maximum) but the concentrations of plant extract of 7 mg/ml exhibited a CL
inhibition of 29.9% (crude extract) and 35.3% (boiled extract).
Key words: plant antioxidants, flavonoids, Astragalus onobrychis.
J. Serb. Chem. Soc.
61(12) 1165-1177 (1996)
UDC 541.515:535.338.1/.3
JSCS-2339
Original scientific paper
Ab
initio investigation of the electronic spectrum of the BH
radical
BOJANA D. OSTOJIC
Faculty of Physical Chemistry, University of Belgrade,
Studentski trg 16,
YU-11000 Belgrade, Yugoslavia
(Received
8 July, revised 17 September 1996)
Potential energy curves for the low-lying singlet and
triplet electronic states of the BH radical and the interaction between
valence- and Rydberg-type species are studied by means of the ab initio
MRD-Cl method. The vertical electronic spectrum of BH is investigated.
Vibrational analysis of the most interesting states is undertaken. Comparison
is made with available experimental data.
Key words: BH radical, potential curves, vertical electronic
spectrum, vibrational analysis.
J. Serb. Chem. Soc.
61(12)1179-1184(1996)
UDC 661.78/66.062.851.22+546.733/:547.466
JSCS-2340
Original scientific paper
Preparation and
characterization of meridional isomers of uns-cis-(ethylenediamine-N,N'-di-3-propionato)cobalt(III) complexes
with some b-amino
acids
TIBOR J. SABO and SRECKO R. TRIFUNOVIC*
Faculty of Chemistry, University of Belgrade, P.O. Box
158, YU-11001 Belgrade and
*Department of Chemistry, Faculty of Science,
University of Kragujevac, P.O.Box
60, YU-34000-Kragujevac, Yugoslavia
(Received
5 June, revised 29 August 1996)
The meridional geometrical isomers of uns-cis-(ethylenediamine-N,N'-di-3-propio-nato)cobalt(III)
complexes with anions of ß-alanine, ß-amino-buteric
and ß-amino-isobuteric acids were prepared in the
reaction of sodium uns-cis-ethylenediamine-N,N'-di-3-propio-nato)-(carbonato)cobaltate(III)
with the corresponding amino acid at 75°C. The complexes were isolated
chromatographically and characterized by elemental analysis, electron
absorption and infrared spectra.
Key words: cobalt(III)
complexes, ß-amino acids, ethylenediamine-N,N'-di-3-propionic
acid.
J. Serb. Chem. Soc. 61(12) 1185-1191 (1996)
UDC 549.514.6:678.023.2
JSCS-2341
Original scientific paper
The
transformation of anatase into rutile during vibro grinding
E. KOSTIC, S. J. KISS, S. BOŠKOVIC and S. ZEC
Institute of Nuclear Sciences - Vinca,
Laboratory 170, P.O.Box 522,
YU-11000 Belgrade, Yugoslavia
(Received
14 March, revised 17 July 1996)
The phase transformation of TiO2 from anatase into rutile
during intense vibro milling was studied. Almost 90%
rutile was detected by X-ray analysis in powder ground for 10 h. With powders
milled up to 2 h the phase transformation was also followed during subsequent
heating. The preceding mechanical activation of anatase
affected the decreasing temperatures of both the initiation and termination of
the phase transformation.
Key words:
mechanical activation, phase transformation, anatase,
rutile.
J. Serb. Chem. Soc.
61(12) 1193-1202 (1996)
UDC 543.42/548.75:66.09
JSCS-2342
Original scientific paper
In-situ real-time
monitoring of processes by remote Fourier transform infrared spectroscopy
JOVAN MIJOVIC, SAŠA ANDJELIC and SRDJAN PEJANOVIC*
Department of Chemical Engineering, Polytechnic
University, Six Metrotech Center, Brooklyn, NY 11201
USA and
*Faculty of Technology and Metallurgy, University of
Belgrade, Karnegijeva 4, YU-11000 Belgrade, Serbia,
Yugoslavia
(Received
18 December 1995, revised 19 July 1996)
Novel experimental setups for remote near-infrared
(NIR) and mid-infrared (MIR) spectroscopy were assembled in our laboratory and
are described in this communication. We can conduct in-situ real-time
monitoring of practically any combination of processes and operating
conditions, while at the same time enjoying the benefits of the ummatched wealth of molecular-level information contained
in the infrared portion of the electromagnetic spectrum. Attractive
possibilities for the application of our monitoring setups exist in diverse
areas, including the aerospace industry for the processing of composites, the
medical field for the transmission of laser energy into various parts of the
human body, the pharmaceutical industry for measurements of dissolution rates
of capsules and tablets, the chemical industry for polymerization, catalysis,
separation and extraction, etc. In this article, we demonstrate the
applicability of our technique for in-situ real-time monitoring of
chemical reactions that occur in a series of non-polymer-forming and
polymer-forming mixtures.
Key words: in-situ monitoring of processes, FTIR spectroscopy,
optical fibers.
J. Serb. Chem. Soc. 61(12)
1203-1208 (1996)
UDC 548.2:546.59
JSCS-2343
Original scientific paper
The growth of Au
clusters on Au(100)
SVETLANA ŠTRBAC, ZLATKO RAKOCEVIC* and TOMISLAV NENADOVIC*
Institute of Electrochemistry, ICTM, P.O.Box 815 YU-11001 Belgrade and
*Vinca Institute of Nuclear
Sciences, P.O.Box 522, YU-11001 Belgrade, Yugoslavia
(Received
13 May, revised 10 July 1996)
The growth of Au clusters on Au(100)
single crystal substrate has been observed by scanning tunneling microscopy
(STM) in air with the surface coverage with deposited gold atoms ranging from
0.007 monolayer (ML) to 0.04ML. Mostly 3×3 clusters with a central vacancy
having eight atoms were obtained .With an increase in surface coverage the
growth of two-dimensional (2D) terraces consisting of condensed 3×3 clusters
were observed. It was assumed that the obtained superstructures are the
precursors of the growth of a layer with a hexagonal structure similar to that
of the well known reconstructed Au(100) phase.
Key words: gold cluster, growth, gold single crystal, STM.
J. Serb. Chem. Soc. 61(12)
1209-1223 (1996)
UDC 546.59:541.132:541.183
JSCS-2344
Original scientific paper
Determination of
the parameters of the process of chloride ions adsorption on the (111) face of
silver
B. M. JOVIC, D. M. DRAZIC* and V. D. JOVIC**
Institut of Technical Sciences SASA, P.O. Box 745, YU-11001 Belgrade, Yugoslavia
*Institute of Electrochemistry ICTM, P.O.Box 815, YU-11001 Belgrade, Yugoslavia and
**Center for Multidisciplinary Studies, University of
Belgrade, P.O.Box 373, YU-11001 Belgrade, Yugoslavia
(Received
30 September 1996)
It is shown that an analyis
of the adsorption isotherm type (q - E) dependence (obtained from the Cad -E, LSV or potentiostatic
pulse results) in combination with the sweep rate dependence of the linear
sweep voltammetry (LSV) peak potential (Ep - log u) can give sufficient information for an estimation of the
parameters of the process of chloride ions adsorption on the (111) face of
silver. The process of chloride ions adsorption was found to take place through
two LSV or pseudo-capacitance peaks with the corresponding q - E
dependences fitting Frumkin type adsorption
isotherms. The values of the Gibbs energies of adsorption (DG°ads) and of the interaction
parameters f were determined for both states of the adsorbate. By analysis of
the previously mentioned dependences it is shown that the first peak (I)
corresponds to the formation of a randomly distributed layer of adsorbed Cl and
AgCl which takes place through three steps, with the rate-determining step
being the formation of absorbed AgCl. The second sharp peak (II) is ascribed to
a phase transformation process which includes all the three previously
mentioned steps and a fourth, rate-determining one, the crystallization of a 2D
layer of (111) oriented AgCl.
Key words: chloride ions adsorption, kinetics, parameters of
adsorption isotherm, AgCl layer formation.
J. Serb. Chem Soc. 61(12) 1225-1232 (1996)
UDC 543.251:541.126
JSCS-2345
Original scientific paper
The current
distribution in an electrochemical cell.
Part III. A novel approach to the determination of the
throwing power of an electroplating electrolyte and the effect of the cell
geometry
KONSTANTIN I. POPOV, STRAHINJA K. ZECEVIC, SLAVIŠA M. PEŠIĆ
and ZORAN S. STOJANOVIĆ
Faculty of Technology and Metallurgy, University of
Belgrade, Karnegijeva 4, P.O. Box 494, YU-11001
Belgrade, Yugoslavia
A new definition
of the throwing power index is proposed which takes into account the effect of
the electrode edges. The earlier defined throwing power index is modified to
show the influence of the geometric parameters, i.e., inter-electrode
distance, l, distance between the side walls and the edges of the
electrodes, L, and the electrode width, A. Using normalized
polarization curves obtained from the system (-)Cu/CuSO4, H2SO4, H2O/Cu(+), the throwing power is qualitatively discussed
and calculated as a function of inter-electrode distance and electrode
edge-side wall distance. The results obtained are in agreement with
expectations illustrating well the effect of the cell geometry on the current
distribution.
Key words: metal deposition, electrochemical cell, current
distribution.
J. Serb. Chem. Soc. 61(12)
1233-1240 (1996)
UDC 543.279/546.11/:541.135.52
JSCS-2346
Original scientific paper
Ring detection
of hydrogen evolution on a rotating disc-ring electrode
J. P. POPIĆ, M. AVRAMOV-IVIĆ and D. M. DRAZIĆ
ICTM-Institute of Electrochemistry, Njegoševa 12, P.O.Box 816, YU-11001 Belgrade,
Yugoslavia
(Recieved 30 September 1996)
The rotating disc-ring technique with a Pt ring was
used to quantitatively detect H2 evolution on a disc electrode. Problems with the slow decrease of the
Pt ring activity for the oxidation of hydrogen were prevented by activation of
the Pt ring by anodic-polarization to 0.84 V vs. RHE for 1 min before each
measurement. The applicability of the proposed measuring technique was
demonstrated for an Al disc-Pt ring system in 0.5 M NaCl
aqueous solution during the cathodic and anodic polarization of an Al disc.
Key words: corrosion, current efficiency, H2 detection, disc-ring
technique.