JOURNAL of the Tunisian Chemical Society

serving the Research, the Education and the Industry

Chemical composition and antimicrobial effects of Tunisian Ruta chalepensis l. Essential oils

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The chemical composition of essential oils extracted from different fresh parts of Ruta chalepensis: flowers, leaves and stems, was analysed using GC and GC-MS. Fifty three components were identified in the oil of each organ. Ketones occurred as the major constituent of the three organs volatile oils while nonan-2-one was the most notably dominating compound in stems essential oil and undecan-2-one was the major compound in flowers and leaves essential oils. The antimicrobial activity of the indicated volatile fractions was screened against eight bacterial species: Staphylococcus epidermidis CIP 106510, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Micrococcus luteus NCIMB 8166, Escherichia coli ATCC 35218, Salmonella thyphymerium LT2, Listeria monocytogenese ATCC 19115 and Enterococcus faecium 29212 using both disc diffusion and dilution methods. Their antifungal activity was tested against nine fungal species Aspergillus niger (onion), Alternaria solani (potato), Penicillium digitatum (orange), Botrytis cinerea (tomato), Fusarium sambucium (potato), Fusarium solani (potato), Trichoderma harzianum T1 (soil), Trichoderma viride TV (soil) and Fusarium oxysporum F33 (potato). So that leaves essential oil was more active than stems and flowers ones, it shows an important antifungal activity against Trichodrema viride TV. In addition, antimicrobial effects of previously prepared essential oils have been investigated against fifteen Candida species. Thus, all volatile fractions presented significant effects against Candida albicans ATCC 90028.

E. Ben Bnina, S. Hammami, M. Daamii-remadi, H. Ben Jannet, Z. Mighri

Ruta chalepensis, Essential oil, Chemical composition, GC and GC-MS, Antibacterial and Antifungal activities

Pages 1-9

Novel sesquiterpene lactone and sesquiterpene lactone glucoside from the flowers of the tunisian Pulicaria laciniata (Coss. Et kral.) Thell.

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A sesquiterpene lactone 1 Lacinin and a sesquiterpene lactone glucoside 2 Laciniside, were isolated from the flowers of Pulicaria laciniata. Their structures were elucidated by extensive spectroscopic methods including 1D-(1H and 13C) and 2D-NMR experiments, (CHcorr, HMBC, 1H-1H COSY and NOESY) as well as high resolution ES-MS.

H. Ghouila, A. Beyaoui, Z. Mighri, H. Ben Jannet

Pulicaria laciniata, Asteraceae, Sesquiterpene lactone glucoside, 2D-NMR

Pages 11-15

A convenient approach to novel N-substituted benzimidazoles

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A series of new N-pyrazoyl-benzimidazoles 4 have been synthesized through a two-steps reaction using 5,2-aminophenylamino-3-(2-hydroxyphenyl)-1H-pyrazole 2 as a useful precursor. All prepared compounds have been fully characterized by mass spectrometry, 1H, 13C and 2D NMR techniques.

S. Hammami, A. Romdhane, R. Gharbi, B. Trimèche, M.A. Hamza, Z. Mighri

1H-pyrazole, condensation reaction, N-pyrazoyl-benzimidazoles

Pages 17-20

Caractérisation de l’huile des graines de l’orange maltaise (Citrus sinensis) poussant en Tunisie

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Triacylglycerol, fatty acid and sterol composition of fixed oil obtained from of Citrus sinensis seeds from Tunisia have been investigated. The seeds contained 17.3% fixed oil. The main TAGs were SLL (21.22%), PLL (16.21%), POL (12.80%), SOL+POO (10.97%) et OLL (10.57%). Linoleic acid (38.81%) was the dominating fatty acid followed by palmitic (26.42%) and oleic (24.63%) acids. the seeds contain 477.1 mg/100 g of total sterols with the predominance of β-sitosterol which accounted for 74.95% of the total sterol content in seed oil. The tocopherols content is 73,42 mg/Kg with the predominance of alpha tocopherol (98.8 % of total tocopherols).

I. El Mannoubi, T. Skanji, S. Barrek, H. Zarrouk

Citrus sinensis, lipides,triglycerides, fatty acids, sterols, tocopherols

Pages 31-36

Synthèse d’une série de N-sulfonyl bromofluorocarbamates

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The reaction of bromofluoroalcohols with aryloxy and alkoxysulfonyl isocyanates under N2 atmosphere at 25°C without solvent gave the corresponding N-sulfonylbromofluorocarbamates in good yields. Initial tests on cyclisation of these carbamates in basic media showed that a new class of oxazolidine-2-ones could be prepared.

A. Radhouani, I. Chehidi, M. Béji

Bromofluoroalcohol, N-aryloxy and alkoxysulfonyl isocyanate, N-sulfonyl bromofluorocarbamate, oxazolidin-2-one

Pages 37-41

Etude cinétique par HPLC/UV de la dégradation d’un carbamate insecticide, l’Aminocarb en milieu aqueux

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This paper deals with the kinetic hydrolysis mechanism of Aminocarb, the 3-methyl-4-dimethylaminophenyl-N-methylcarbamate in aqueous media. This work is carried out by reversed phase Liquid Chromatography and LC-MS. The determination of 3-methyl-4-dimethylamino-phenol, as the main product of Aminocarb hydrolysis gives evidence by LC-MS. The obtained positive activation entropy ΔS = + 31.3 J mol-1 K-1 indicated an E1cB mechanism involving unimolecular collapse of the Aminocarb via a methylisocyanate intermediate. This elimination process is confirmed by the position of the point corresponding to the Aminocarb on the Br?nsted and Hammett lines, determined for a serie of substituted N-methylcarbamate which the decomposition mechanism in aqueous media procede via E1cB.

F. Boujelbane, N. Ben Hamida

Aminocarb, degradation, mechanism, LC-ESI-MS

Pages 43-51

Etude par spectroscopie RMN et UV-visible des interactions solvants nématiques-parabenzoquinone

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Orientation of parabenzoquinone molecule was studied in three different nematic solvents (Phase 4, ZLI 1132, ZLI 1695) and in magic mixture ZLI 1132/EBBA at different temperatures. Ultraviolet (UV)-visible spectroscopy indicated that charge transfer complexes were proved to exist even with the non aromatic solvent ZLI 1695. NMR results showed that the dispersion forces' role is minimal even in magic mixture where long range interactions between the parabenzoquinone quadrupolar moment and the solvent electric field gradient are almost canceled.

Y. Arfaoui, E. Haloui

parabenzoquinone, NMR, UV-visible, nematic, interaction

Pages 53-61

Synthesis, crystal structure and characterization of a new fluoride zirconate hybrid, (C8H12N)4•Zr2F12

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Solvothermal preparation, characterization by IR absorption, DTA-TG analysis, X-ray thermodiffraction and crystal structure determination are reported for a new fluoride zirconate (C8H12N)4•Zr2F12. The cell is monoclinic (P21/a ; Z = 2) with a = 14.407(2) Å ; b = 7.727(3) Å ; c = 17.37(4) Å and β = 94.83(6)°. The structure solution is refined to R = 0.025 and Rw = 0.079 using 2789 independent reflections. The 3D arrangement consists of (001) layers of Zr2F12 dimers and phenylethylammonium cations in which organic cations are linked to fluoride ions by N-H…F hydrogen bonds. The interlayer Van der Waals interactions are weak and the thermal stability of the structure is poor. Thermal analysis and X-ray thermodiffraction reveal a phase transition at T ≈ 100°C before the decomposition starts at T ≈ 120°C and ends at T ≈ 350°C to give ZrF4.

I. Balti, T. Ben Chaabane, M. Leblanc, A. Ben Ali

Solvothermal, XRD, crystal structure, hybrid

Pages 71-78

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