J. Serb. Chem. Soc. 75 (7) 875–891 (2010)
UDC 582.951.4.002.68+547.56+543:577.164.3; JSCS–4014; doi: 10.2298/JSC091109055W; Original scientific paper

Discrimination and classification of tobacco wastes by identification and quantification of polyphenols with LC–MS/MS
JUN WANG*^,**, DINGQIANG LU*, HUI ZHAO*, BEN JIANG*, JIALI WANG*, XIUQUAN LING*, HONG CHAI* and PINGKAI OUYANG*

*School of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, P. R. China

**School of Biotechnology and Environmental Engineering, Jiangsu University of Science and Technology, Zhenjiang 212018, P. R. China

(Received 9 November 2009, revised 25 February 2010)

The chemical composition of polyphenols in tobacco waste was identified by HPLC-PDA–ESI/MS/MS and the contents of chlorogenic acids and rutin in 10 varieties of tobacco wastes were determined by HPLC–UV. The relationships between the contents of active polyphenols and the varieties of tobacco wastes were interpreted by hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results showed that 15 polyphenols were identified in a methanolic extract of dried tobacco waste. The tobacco wastes were characterized by high levels of chlorogenic acids (3-CQA, 5-CQA, and 4-CQA) and rutin; their ranges in the 10 tobacco varieties were 0.116–0.196, 0.686–1.781, 0.094–0.192, and 0.413–0.998 %, respectively. According to multivariate statistics models, two active compound variables can be considered important for the discrimination of the varieties of tobacco wastes: chlorogenic acids and rutin. Consequently, sAMples of 10 tobacco varieties were characterized into three groups by HCA based on the PCA pattern. In conclusion, tobacco waste could be used as a new pharmaceutical material for the production of natural chlorogenic acids and rutin in the ethnopharmacological industry.

Keywords: tobacco (Nicotiana tabacum L.) waste; HPLC–PDA–ESI/MS/MS; chlorogenic acids; rutin; multivariate statistical analysis.

J. Serb. Chem. Soc. 75 (7) 893–902 (2010)
UDC 633.888:575.21:543.05(497.113); JSCS–4015; doi: 10.2298/JSC091019070D; Original scientific paper

Δ⁹-Tetrahydrocannabinol content in cannabis sAMples seized in Novi Sad during 2008

MAJA DJURENDIĆ-BRENESEL, NIKŠA AJDUKOVIĆ, KATARINA ŠTAJNIC-RISTIĆ, VLADIMIR PILIJA and IGOR VESELINOVIĆ

Institute of Forensic Medicine, Clinical Center Vojvodina, Hajduk Veljkova 7–9, 21000 Novi Sad, Serbia

(Received 19 October, revised 15 December 2009)

The three main cannabinoids Δ⁹-tetrahydrocannabinol (Δ⁹-THC), cannabidiol (CBD) and cannabinol (CBN) were identified and determined quantitatively using a GCD (GC-EI) instrument in 280 sAMples of illicit herbal cannabis, seized by the Police authorities in Novi Sad, during 2008. The sAMples were sent to the Institute of Forensic Medicine, Clinical Center Vojvodina, for forensic chemical analysis. The cannabinoid content of the sAMples enabled the classification of the cannabis into three chemical phenotypes and the differentiation into drug and textile-cannabis, using the Waller classification index. This differentiation has great forensic significance in the classification of certain cases as a criminal action. The experimental results showed that the Δ⁹-THC content in illicitly circulated cannabis slightly decreased from January to December 2008, as did the quality of the drug-cannabis. The reasons for the quality variations could lie in the geographical origin of the cannabis plants, the conditions of plants storage, various parts of the plants in sAMples and the time elapsed between harvesting and chemical analysis.

Keywords: cannabinoids; forensic sAMples; GCD analysis; phenotype; Waller index.

J. Serb. Chem. Soc. 75 (7) 903–915 (2010)
UDC 633.86+667.272/.276:543.544.5; JSCS–4016; doi: 10.2298/JSC091027071G; Original scientific paper

Determination of natural colorants in plant extracts by high-performance liquid chromatography
RENETA GEVRENOVA

Department of Pharmacognosy, Faculty of Pharmacy, Medical University – Sofia, Dunav str. 2, 1000 Sofia, Bulgaria

(Received 27 October 2009, revised 12 January 2010)

The determination of the colouring compounds apigenin (1), lawsone (2), juglone (3) and indigotin (4) in plant extracts using HPLC–UV/Vis methods is reported. The methods were applied to the analysis of 1–4 in ethanolic and propylene glycolic extracts originating, respectively, from chAMomile (ChAMomilla recutita [L] Rauschert, Asteraceae), henna (Lawsonia inermis L., Lythraceae), walnut (Juglans regia L., Juglandaceae) and natural indigo (Indigofera sp., Fabaceae). In the case of the indigo extracts, an optimized acid hydrolysis was applied. HPLC separations were performed on a Hypersil ODS RP18 column using linear gradient elution progrAMs. The detection limits for 1–4 were 0.11, 0.6, 0.10, 0.089 μg mL^-1, respectively. The procedure did not involve any sAMple “clean-up” methods. The AMounts of the colouring compounds ranged from 0.006 (3) to 0.13 mg mL^-1 (4) in the ethanolic extracts and from 0.22 (2) to 1.44 mg mL^-1 (4) in propylene glycolic extracts. The proposed HPLC methods are advantageous in terms of sAMple preparation and the selective separation of the compounds. The plant dye extracts are commonly used in hair colouring formulations. The results indicate that the methods developed may serve for the quantitative control of dying plants and cosmetic products.

Keywords: apigenin; indigotin; juglone; lawsone; high-performance liquid chromatography.

J. Serb. Chem. Soc. 75 (7) 917–927 (2010)
UDC 547.1’128+547.79:542.9+547.571+547.551:615.281/.282; JSCS–4017; doi: 10.2298/JSC081216063S; Original scientific paper

Synthetic, structural and biological studies of organosilicon(IV) complexes of Schiff bases derived from pyrrole-2-carboxaldehyde
KIRAN SINGH and DHARAM PAL*

Department of Chemistry, Kurukshetra University, Kurukshetra-136 119, India

*Department of Applied Sciences, J.I.E.T., Jind-126102, Haryana, India

(Received 16 December 2008, revised 26 April 2010)

Selected new organosilicon(IV) complexes having the general formula R₂SiCl[L] and R₂Si[L] ₂ were synthesized by the reactions of Me₂SiCl₂ with Schiff bases (5-mercapto-4-[(1H-pyrrol-2ylmethylene)AMino]-s-triazole, 5-mercapto-3-methyl-4-[(1H-pyrrol-2ylmethylene)AMino]-s-triazole and 3-ethyl-5-mercapto-4-[(1H-pyrrol-2ylmethylene)AMino]-s-triazole) in 1:1 and 1:2 molar ratios. All of the compounds were characterized by elemental analysis, molar conductance, and IR, UV, ¹H-, ¹³C- and ²⁹Si-NMR spectral studies. All the spectral data suggest an involvement with an azomethine nitrogen in coordination to the central silicon atom. With the help of above-mentioned spectral studies, penta and hexacoordinated environments around the central silicon atoms in the 1:1 and 1:2 complexes, respectively, are proposed. Finally, the free ligands and their metal complexes were tested in vitro against some pathogenic bacteria and fungi to assess their antimicrobial properties.

Keywords: antifungal; antibacterial; silicon complexes; s-triazole; Schiff bases.

J. Serb. Chem. Soc. 75 (7) 929–934 (2010)

J. Serb. Chem. Soc. 75 (7) 935–941 (2010)

UDC 546.732’742’562.004.12:547.455.4; JSCS–4019; doi: 10.2298/JSC090804069C; Original scientific paper

J. Serb. Chem. Soc. 75 (7) 943–950 (2010)

UDC 547.538.2+66.095.252:537.872:539.193; JSCS–4020; doi: 10.2298/JSC091201068J; Original scientific paper

J. Serb. Chem. Soc. 75 (7) 951–963 (2010)

UDC 546.39’185+546.27+542.913; JSCS–4021; doi: 10.2298/JSC090228064M; Original scientific paper

Synthesis and characterization of AMmonium phosphate fertilizers with boron

ANGELA MAGDA, RODICA PODE, CORNELIA MUNTEAN, MIHAI MEDELEANU and ALEXANDRU POPA*

Faculty of Industrial Chemistry and Environmental Engineering, “Politehnica” University of Timişoara, Victoria Square 2, 300006 Timişoara, Romania

*Institute of Chemistry Timisoara of the Romanian Academy, M. Viteazul Ave, 24, 300223-Timisoara, Romania

(Received 28 February 2009, revised 26 April 2010)

The concentration of boron, an essential micronutrient for plants, presents a narrow range between deficiency and toxicity. In order to provide the boron requirement for plants, and to avoid toxicity problems, boron compounds are mixed with basic fertilizers. Sodium borate pentahydrate was used as a boron source. Ammonium orthophosphates fertilizers with boron were prepared by neutralizing phosphoric acid with AMmonia and addition of variable AMounts of sodium tetraborate pentahydrate to the reaction mixture at a NH₃:H₃PO₄ molar ratio of 1.5. The fertilizers obtained with boron contents ranging from 0.05 to 1 % (w/w) were fully characterized by chemical analysis, thermal analysis, X-ray diffraction and infrared spectrophotometry. The studies showed that up to 500 °C, regardless of the boron content, no significant changes concerning thermal stability and nutritional properties occurred. Above 500 °C, an increase of thermal stability with an increase of the boron content was observed. X-Ray diffraction of a heat-treated sAMple containing 5 % (w/w) boron indicated the appearance of boron orthophosphate, BPO₄, as a new crystalline phase, and the disappearance of the previous structures above 500 °C, which explains the increase in thermal stability.

Keywords: sodium borate pentahydrate; fertilizer; micronutrient; diAMmonium hydrogen phosphate; AMmonium dihydrogen phosphate; boron orthophosphate.

J. Serb. Chem. Soc. 75 (7) 965–973 (2010)

UDC 666.32+661.182+66.094.3:61.000.57; JSCS–4022, doi: 10.2298/JSC090617062J; Original scientific paper

Singlet oxygen generation by higher fullerene-based colloids

SVETLANA P. JOVANOVIĆ, ZORAN M. MARKOVIĆ, DUŠKA N. KLEUT, VLADIMIR D. TRAJKOVIĆ*, BRANKA S. BABIĆ-STOJIĆ, MIROSLAV D. DRAMIĆANIN and BILJANA M. TODOROVIĆ MARKOVIĆ

Vinča Institute, P.O. Box 522, 11001 Belgrade, Serbia

*Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotića 1, 11000 Belgrade, Serbia

(Received 17 June 2009, revised 26 April 2010)

In this paper, the results of the synthesis and characterization of higher fullerene-based colloids is presented. The generation of singlet oxygen 1O2 (¹Δg) by fullerene water-based colloids (nC60, nC70 and nC84) was investigated. It was found by electron parAMagnetic resonance spectroscopy that the generation of singlet oxygen was the highest by the nC84 colloid. The AMplitude of the electron parAMagnetic resonance (EPR) signal was two orders of magnitude higher than the AMplitude of the EPR signals which originated from nC60 and nC70. The surface morphology and the structure of the particles of the water-based colloids were investigated by atomic force microscopy (AFM). The AFM study showed that the average size of the nC60, nC70 and nC84 were 200, 80 and 70 nm, respectively. In addition, the particle size distribution of the nC60, nC70 and nC84 colloids was determined by dynAMic light scattering (DLS) measurements.

Keywords: higher fullerene; colloid; electron parAMagnetic resonance spectroscopy; atomic force microscopy; dynAMic light scattering.

J. Serb. Chem. Soc. 75 (7) 975–985 (2010)

UDC 615.453.4+546.131:543.544.5.068.7; JSCS–4023; doi: 10.2298/JSC090728065M; Original scientific paper

Development and application of a validated HPLC method for the analysis of dissolution sAMples of mexiletine hydrochloride capsules

DRAGAN M. MILENOVIĆ and ZORAN B.TODOROVIĆ*

“Zdravlje-Actavis” Company, Analytical Department, R &AMp; D, Vlajkova 199, 16000 Leskovac, Serbia

*Faculty of Technology, Bulevar oslobođenja 124, 16000 Leskovac, University of Niš, Serbia

(Received 28 July 2009, revised 16 February 2010)

The aim of this work was to develop and validate a simple, efficient, sensitive and selective method for the analysis of dissolution sAMples of mexiletine hydrochloride capsules by HPLC without the necessity of any time-consuming extraction, dilution or evaporation steps prior to drug assay. Separation was performed isocratically on a 5 µm LiChrospher 60, RP-Select B column (250·4 mm ID) using the mobile phase buffer–acetonitrile (60:42, v/v) at a flow rate of 1.2 mL min^-1 and UV detection at 262 nm. The elution occurred in less than 10 min. The assay was linear in the concentration range 50–300 µg mL^-1 (r² = 0.9998). The validation characteristics included accuracy, precision, linearity, specificity, limits of detection and quantification, stability, and robustness. Validation acceptance criteria were met in all cases (the percent recoveries ranged between 100.01 and 101.68 %, RSD < 0.44 %). The method could be used for the determination of mexiletine hydrochloride and for monitoring its concentration in in vitro dissolution studies.

Keywords: mexiletine hydrochloride; dissolution; method validation; HPLC.

J. Serb. Chem. Soc. 75 (7) 987–996 (2010)

UDC 678.544:544.35:546.131+546.32–36; JSCS–4024; doi: 10.2298/JSC091009073L; Original scientific paper

A study on the microstructure of a nitrate ester plasticized polyether propellant dissolved in HCl and KOH solutions

YONG LIU*^,**, LUOXIN WANG***, XINLIN TUO**, SONGNIAN LI*^,** and WEIMIN YANG*

*College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China

**Department of Chemical Engineering, Tsinghua University, Beijing 100084, China

***Wuhan University of Science and Engineering, Key Laboratory of Green Processing and Functional Textiles of New Textile Materials, Ministry of Education, Wuhan 430073, China

(Received 9 October 2009, revised 19 January 2010)

Understanding of how the properties and performance of nitrate ester plasticized polyether (NEPE) propellants relate to microstructure is complicated by numerous components that have different characteristics. One approach to alleviating these complications is to observe a microstructure that has lost one or several components. This article exAMines the dissolution process, mass loss and change of the ion concentration of propellants in acid and alkali solutions. A scanning electron microscope was used to observe the dissolved residual of the propellants. The results revealed that the main constituents of NEPE propellant have different dissolving properties in solutions of HCl and KOH. By monitoring the dissolution process of NEPE propellant in HCl and KOH solutions, it was found that the microstructure of the propellant is generally compact and the polymer binder not only binds all the other components, but also protects the inner part of the propellant in solution.

Keywords: NEPE propellants; microstructure; interfaces; scanning electron microscope (SEM); swelling.

J. Serb. Chem. Soc. 75 (7) 997–1003 (2010)

UDC 547.21:536.423.1; JSCS–4025; doi: 10.2298/JSC091123067J; Note

NOTE

Reliable prediction of heat of vaporization of n-alkanes at 298.15 K

JOVAN D. JOVANOVIĆ and DUŠAN K. GROZDANIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia

(Received 23 November 2009, revised 3 March 2010)

A reliable model for the prediction of the heat of vaporization for n-alkanes at 298.15 K with the number of carbon atoms and normal boiling point as the only input parAMeters is recommended. The new model is compared with other literature models and was found to give the best results with absolute mean percentage deviation of 0.81 % and maximum absolute percentage deviation of 2.93 %.

Keywords: heat of vaporization; n-alkanes; prediction; model.

J. Serb. Chem. Soc. 75 (7) 1005–1018 (2010)

UDC 504.45.055+549.25+556.16:504.06; JSCS–4026; doi: 10.2298/JSC090217061P; Original scientific paper

A simulation experiment as a method for the investigation of the mobility of heavy metals from inundated land

DJOKICA PETROVIĆ, MARIJA TODOROVIĆ*, DRAGAN MANOJLOVIĆ* and VOJIN D. KRSMANOVIĆ*

Vinča Institute, Laboratory for Radioisotopes, P.O. Box 522, 11001 Belgrade, Serbia

*Faculty of Chemistry, University of Belgrade, P.O. Box 51, 11158 Belgrade 118, PAK: 105305, Serbia

(Received 17 February 2009, revised 4 May 2010)

A simulation experiment was used to study the interaction of river water with different soils (arable land, orchards, meadows, pastures and forestland). The results obtained by sequential extraction before and after the simulation experiment were compared in order to determine the substrates of the heavy metals in inundated land and to evaluate their mobility. SAMples of various soils were collected from the region of the future accumulation Lake Bogovina (Serbia) and analysed for ten elements using AAS, GFAAS and ICP. Investigation of the nature of the association of heavy metals and the identification of their substrates were provided by a five-step sequential extraction. Correlation analysis was used as a method for the determination of the substrates for heavy metals. The good correlation AMong the microelements and certain macroelements indicated the substrates of the microelements. Manganese and iron had a good correlation with most of the microelements. Calcium had only a few correlations with some microelements. Some elements, such as nickel and cadmium, had one substrate before and another after the simulation experiment.

Keywords: zinc; heavy metals; accumulation lake; sequential extraction; inundated soil.

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