JSCS Vol 68, No. 1
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Impresum
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J.Serb.Chem.Soc.
68(1)1–7(2003) |
To download this article click here 101 KB |
Hydrogen bonding in push-pull
5-substituted-2-alkylidene-4-oxothiazolidines: 1H-NMR
spectroscopic study
R. MARKOVI*,**, A. SHIRAZI***, Z. DZAMBASKI**,
M. BARANAC*,** and D. MINIC****
*Faculty of Chemistry, University
of Belgrade, Studentski trg 16, P. O. Box 158, YU-11001 Belgrade,
**Center for Chemistry ICTM, P. O. Box 815, YU-11000 Belgrade,
***Chemistry Department, University of California, Santa Barbara,
Santa Barbara, CA 93106, USA and
****Faculty of Physical Chemistry, University of Belgrade,
Studentski trg 12-16, P. O. Box 137, YU-11001 Belgrade, Yugoslavia
(Received
7 March, revised 24 September 2002)
Application
of dynamic 1H-NMR spectroscopy added to the understanding of the hydrogen
bonds existing in the structurally related
5-substituted-2-alkylidene-4-oxothiazolidines in polar and apolar solvents. The
equilibrated mixtures of these typical push-pull alkenes in CDCl3 consist of
the intramolecularly H-bonded (E)-isomer and intermolecularly H-bonded (Z)-isomer
in varying proportions which depend on the solvent polarity. For the
representative of the series, (Z)-2-(5-ethoxycarbonylmethyl-4-oxothiazolidin-2-ylidene)-1-phenylethanone,
a concentration effect on the degree of intermolecular hydrogen bonding in
apolar CDCl3 has been studied.
Keywords:
push-pull alkenes, hydrogen bonding, 1H-NMR
spectroscopy.
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J.Serb.Chem.Soc.
68(1)9–16(2003) |
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Kinetics of solanidine hydrolytic
extraction from potato (Solanum tuberosum L.) haulm in solid-liquid
systems
NADA C. NIKOLIC
and MIHAJLO Z. STANKOVIC
Faculty of Technology, University of Nis, Bulevar oslobodjenja
124, 16000 Leskovac, Yugoslavia
(Received 11 July,
revised 19 September 2002)
Dried and milled haulm of potato (Solanum
tuberosum L.) was used as the solid phase. An ethanolic solution of
hydrochloric acid mixed with chloroform in different volume ratios was the
liquid phase. The aim of paper was to unite in a single step the processes of
glycoalkaloids extraction from haulm, their hydrolysis to solanidine and the
extraction of solanidine. This could make the procedure of obtaining solanidine
faster and simpler. The best degree of solanidine hydrolytic extraction of 84.5
% was achieved using 10 % w/v hydrochloric acid in 96 % vol. ethanol mixed with
chloroform in a volume ratio of 2:3, after 120 min of hydrolytic extraction.
Keywords: potato, haulm, glycoalkaloids,
hydrolysis, solanidine, extraction.
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J.Serb.Chem.Soc.
68(1)17–24(2003) |
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Chemical constituents and
antimicrobial activity of the ethanol extracts obtained from the flower, leaf
and stem of Salvia officinalis L.
DRAGAN T.
VELICKOVIC, NOVICA V. RANDJELOVIC*, MIHAILO S. RISTIC**, ANA S. VELICKOVIC***
and ANDRIJA A. SMELCEROVIC****
AD
“Zdravlje” Pharmaceutical and Chemical Industry, Vlajkova St. 199, YU-16000
Leskovac,
*Faculty
of Technology, Bulevar Oslobodjenja St. 124, YU-16000 Leskovac,
**Institute
for Medicinal Plants Research “Dr. Josif Pancic”, Tadeusa Koscuska St. 1,
YU-11000 Belgrade,
***Medical
Center “Mosa Pijade”, Department of General Practice, Rade Koncara St. 2,
YU-16000 Leskovac and
****Chemical
Industry “Nevena”, Djordja Stamenkovica St. bb., YU-16000 Leskovac, Yugoslavia
(Received 19 August
2002)
In this paper a comparison of the chemical
composition and antimicrobial action of the ethanol extracts from the flower,
leaf and stem of the herbal species Salvia officinalis L. (Lamiaceae),
originating from the southeast region of Serbia was carried out. The chemical
composition of the extracts was determined by GC-FID and GC-MS analyses. Manool
has the highest level of all the components (9.0–11.1 %). Antimicrobial
activity was determined by the diffusion and dilution method, whereby the
latter one was modified by use of cellulose discs, and it was applied for the
determination of the minimal inhibitory (MIC) and minimal lethal concentrations
(MLC). The leaf extract has a stronger antimicrobial activity than those of the
flower and stem.
Keywords: Salvia officinalis L., Lamiaceae,
extracts composition, manool, antimicrobial activity.
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J.Sereb.Chem.Soc.
68(1)25–33(2003) |
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Insulin-induced lipid binding to
hemoglobin
NENAD
TOMASEVIC, MILAN NIKOLI, KAREN KLAPPE*, DICK HOEKSTRA* and VESNA NIKETI
Chemistry Department, University of Belgrade, Studentski trg 16,
P. O. Box 158, YU-11001 Belgrade, Yugoslavia and
*Laboratory of Physiological Chemistry, University of Groningen,
Bloemsingel 10, 9712 KZ Groningen, The Netherlands
(Received 22 July 2002)
Under hypoglycemic conditions, concomitant
hyperinsulinism causes an apparent modification of hemoglobin (Hb) which is
manifested by its aggregation (Niketi} et al., Clin. Chim. Acta 197
(1991) 47). In the present work the causes and mechanisms underlying this Hb
modification were studied. Hemoglobin isolated from normal erythrocytes
incubated with insulin was analyzed by applying 31P-spectrometry and lipid extraction and analysis. To study the
dynamics of the plasma membrane during hyperinsulinism, a fluorescent
lipid-analog was applied. In the presence of insulin, phosphatidylserine (PS),
phosphatidylethanolamine (PE) and cholesterol were found to bind to Hb. Lipid
binding resulted in Hb aggregation, a condition that can be reproduced when
phospholipids are incubated with Hb in vitro. Using a fluorescent
lipid-analog, it was also shown that exposing erythrocytes to
supraphysiological concentrations of insulin in vitro resulted in the
internalization of lipids. The results presented in this work may have
relevance to cases of diabetes mellitus and hypoglycemia.
Keywords: insulin, erythrocyte, hypoglycemia,
hyperinsulinism, membrane lipids, hemoglobin.
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J.Serb.Chem.Soc.
68(1)35–46(2003) |
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Simultaneous correlation of the
excess enthalpy and W-shaped excess heat capacity of 1,4-dioxane+n-alkane
systems by PRSV-HVOS CEOS
MIRJANA LJ.
KIJEVCANIN, ALEKSANDAR B. DJORDJEVIC, IVONA R. GRGURIC, BOJAN D. DJORDJEVIC and
SLOBODAN P. SERBANOVIC
Faculty of Technology and Metallurgy, University of Belgrade,
Karnegijeva 4, P. O. Box 35-03, Belgrade, Yugoslavia
(Received 9 September
2002)
In this work the Peng-Robinson-Stryjek-Vera
(PRSV) equation of state coupled with the Huron-Vidal-Orbey-Sandler (HVOS) rule
was tested for the correlation of the excess enthalpy (HE) and the excess heat capacity (cpE) alone and
simultaneously. The HVOS mixing rule incorporates the NRTL equation as the GE model. All calculations were performed using the linear and
reciprocal forms of the temperature dependent parameters of the models. For all
the evaluations the 1,4-dioxane+n-alkane systems were chosen having in
mind the unusually W-shaped concentration dependence of cpE for these systems. The
correlation of the HE and cpE data alone for all the
investigated systems using four coefficients and for the simultaneous
correlation of HE+cpE data using six coefficients of the temperature
dependent parameters of the PRSV-HVOS models could be considered as being very
satisfactory.
Keywords: thermodynamics, n-alkane,
1,4-dioxane, excess properties, CEOS.
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J.Serb.Chem.Soc.
68(1)47–56(2003) |
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Excess molar volume of acetonitrile
+ alcohol systems at 298.15 K. Part II: Correlation by cubic equation of state
IVONA R.
GRGURIC, MIRJANA LJ. KIJEVCANIN, BOJAN D. DJORDJEVIC, ALEKSANDAR Z. TASIC and
SLOBODAN P. SERBANOVIC
Faculty of Technology and Metallurgy, University of Belgrade,
Karnegijeva 4, P. O. Box 35-03, Belgrade, Yugoslavia
(Received 18 September
2002)
The excess molar volume VE of the binary liquid systems acetonitrile + methanol and
acetonitrile + ethanol, experimentally determined in the previous part, were
correlated by the PRSV CEOS coupled with the vdW and TCBT mixing rules. The
results obtained show that the number and position of the interaction
parameters of these models are of great importance for a satisfactory fitting
of VE data.
Keywords: excess molar volume, CEOS,
correlation, alcohol, acetonitrile.
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J.Serb.Chem.Soc.
68(1)57–63(2003) |
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Normal and reversed phase
thin-layer chromatography of new 16,17-secoestrone derivatives
MARIJANA M.
ACANSKI, SUZANA JOVANOVIC-SANTA* and LIDIJA R. JEVRIC
Department of General and Inorganic Chemistry, Faculty of
Technology, University of Novi Sad, Bulevar cara Lazara 1, YU-21000 Novi Sad
and
*Institute of Chemistry, Faculty of Science, University of Novi
Sad, Trg Dositeja Obradovi}a 3, YU-21000 Novi Sad, Yugoslavia
(Received 31 August,
revised 18 September 2002)
The retention behaviour and separation ability
of a series of new 16,17-secoestrone derivatives has been studied on silica
gel, alumina and C-18 silica gel layers with non-aqueous and aqueous-organic
mobile phases. The retention behavour and separation ability are discussed in
terms of the nature of the solute, eluent and stationary phase.
Keywords: thin-layer chromatography, silica
gel, alumina, C-18 silica gel, 16,17-secoestrone derivatives.
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J.Serb.Chem.Soc.
68(1)65–73(2003) |
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Spectrophotometric determination of
phosphorus in coal and coal ash using bismuth-phosphomolybdate complex
RANDJEL P.
MIHAJLOVIC NATA[A R. IGNJATOVIC, MARIJA R. TODOROVIC* IVANKA
HOCLAJTNER-ANTUNOVIC** and VESNA M. KALJEVIC
Faculty of Science, University of Kragujevac, P. O. Box 60,
YU-34000 Kragujevac,
*Faculty of Chemistry, University of Belgrade, P. O. Box 158,
YU-1001 Belgrade and
**Faculty of Physical Chemistry, University of Belgrade, YU-11001
Belgrade, Yugoslavia
(Received 5 March,
revised 7 October 2002)
A modified spectrophotometric method using the
bismuth phosphomolybdate complex for the determination of phosphorus in coal
and coal ash is suggested. Bismuth together with phosphate and molybdate forms
a very stable complex in acid medium which turns blue (“molibdenum blue”) by
reduction with ascorbic acid. The apparent molar absorptivity of PBiMo is
1.66x104 dm3 mol-1cm-1 at 720 nm and 2.10x104 dm3 mol-1cm-1 at 670 nm isobutyl methyl ketone (MIBK). Interference caused by
the ions present are within the tolerance limits (±2 %). Beer’s law is obeyed
in the for concentration range to 0.6 mg/mL (aqueous solution) and to 1.2 mg/mL P (MIBK). The
sesitivity of the proposed method is 0.0078 mg/mL (aqueous solution) and 0.0066 mg/mL (MIBK).
Keywords: spectrophotomery, phosphorus
determination, coal, coal ash, bismuth phosphomolybdate complex.
Copyright & copy; SHD 2002.
February
24, 2003.
For
more information contact: SHD@tmf.bg.ac.yu