Mohamed Kossentini

Reactivite Des N 1 -Tosylamidrazones Vis-À-Vis du Chlorure de Thionyle et du Reactif de Lawesson: Obtention Des Thiatriazoles et Des Triazaphospholines

Thionyl chloride 2 and Lawesson Reagent (L.R.) 4 react with N 1 -tosylamidrazones 1 to give respectively 1-oxyde-1,2,3,5-thiatriazole 3 and triazaphospholines 5 derivatives. The structure of products 3 and 5 is confirmed by IR and NMR spectroscopy.

Chemical composition and chelating activity of Ruta chalepensis L. (Rutaceae) essential oil as influenced by phenological stages and plant organs

Chemical composition and chelating activity of Ruta chalepensis L. essential oils collected from the south-east of Tunisia at the vegetative and the flowering stages were investigated. Essential oils were extracted by hydrodistillation from different organs (leaves, flowers and stems) and analyzed by gas chromatography–flame ionization detector (GC–FID) and GC–mass spectrometry (GC–MS) techniques. The highest essential oil yields were obtained at the flowering stage with a maximum in the flowers (1.8-1.9%). Twenty-five compounds were identified in different essential oils, where ketones and esters constituted the main chemical classes. 2-Nonanone (17.2–25.9%), 2-undecanone (19–37.2%) and octyl acetate (9.1–30.8%) were found to be the major compounds in all essential oils. The majority of essential oil compounds showed homogeneity with respect to the phenological stage and plant organs. At the flowering stage, stems and flowers essential oils showed the highest metal chelating activity, whose ic50 values ranged between 160 and 180 μg/mL.

Essential oil variation in wild populations of Artemisia saharae (Asteraceae) from Tunisia: chemical composition, antibacterial and antioxidant properties

BackgroundArtemisia saharae Pomel is a new taxon of Artemisia herba-alba Asso (Asteraceae) which is endemic to Tunisia and Algeria. This shrub, commonly known as white wormwood or desert wormwood, is largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by several factors such as geographic conditions. Therefore, the aim of the present work is to provide more information about the influence of altitude variation on the essential oil composition, antimicrobial and antioxidant properties of Artemisia saharae growing wild in the same geographical area.ResultsEssential oils were extracted by hydrodistillation of leaves and flowers of the plant collected from seven different altitudes of the Baten Zamour region (southwest of Tunisia). The highest essential oil yields (2.70-2.80%) were obtained for populations of high altitudes.Seventy-five compounds, representing 92.78 to 96.95% of the total essential oils, were separated and identified. Essential oils were characterized by very high percentage of oxygenated monoterpenes (52.1–72.6%) which constituted the predominant class. From the analyzed populations, the major compounds (>7%) were α-thujone, β-thujone, chrysanthenone, camphor, chrysanthenyl acetate, and sabinyl acetate. Sabinyl acetate which was detected in some populations at relatively high percentages (7.7–10.8%) seems to be characteristic to Southern Tunisian A. saharae. The studied essential oil showed a chemical diversity depending on the population altitude as revealed by linear discriminant and cluster analyses.ConclusionsThree population groups associated with altitudinal levels were distinguished. It is worthy to note that the most discriminating compounds of chemical groups were the minor ones. Despite the high variation of essential oil compositions, the high altitude population did not affect severely the antibacterial activity against the most tested strains. Altitude seems to be an important factor influencing the yield and the chemical profile of Artemisia saharae essential oils. Knowledge of the chemical composition of essential oils in relation to environmental factors is a very important quality criterion for their marketing and contributes to their valorization as functional ingredient in food technology.

REACTIVITE DES N 1-TOSYLAMIDRAZONES VIS-À-VIS DU TRICHLORURE DE THIOPHOSPHORYLE ET DU DISULFURE DE CARBONE: OBTENTION DES TRIAZAPHOSPHOLINES ET DES TRIAZOLETHIONES

The condensation of N 1 -tosylamidrazones with thiophosphorus trichloride and carbone disulfide forms a new synthetic method for access to new phosphorus or sulfur heterocycles such as triazaphospholines and triazolethiones.

Synthesis and evaluation of 1,ω-bis(1,2,3,5-thiatriazol-5-yl)alkanes as in vitro and in vivo α-amylase and lipase inhibitors.

Thionyl chloride reacts with 1,ω‐bis‐(1‐tosylamidrazone)alkanes 1 to give a series of 1,ω‐bis‐(4‐alkyl‐2‐tosyl‐1,2,3,5‐thiatriazol‐5‐yl)alkanes 2. All the newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, elemental analysis, and ESI–MS spectral data. All the new compounds were screened for their inhibitory effect on key enzymes related to diabetes and obesity, such as α‐amylase and lipase. In vitro and in vivo studies revealed that these thiatriazole derivatives exert an inhibitory action against these key enzymes. Moreover the administration of these compounds to surviving diabetic rats induced a significant decrease in plasma glucose level. Additively 2d significantly protected the liver–kidney functions and modulated lipid metabolism, which were evidenced by the decrease in aspartate transaminase (AST), alanine transaminase (ALT), and gamma‐glutamyl transpeptidase (GGT) activities and creatinine, urea albumin, LDL‐cholesterol and triglycerides levels as well as an increase in the HDL‐cholesterol level in surviving diabetic rats. Overall, the findings of the current study indicate that 2d exhibits attractive properties and can, therefore, be considered for future application in the development of anti‐diabetic and hypolipidemic drugs.

Action du Tris(Diméthylamino)phosphine et de l'Oxyde de P,P-dichlorophenylphosphine sur les N 1Tosylamidrazones: Obtention des 3-(Dimethylamino) 1,2,4,3-triazaphospholines et des 3-Oxo1,2,4,3-triazaphospholines

The reaction of N1-tosylamidrazones with tris(dimethylamino)phosphine and P,P-dichlorophenylphosphine oxide provides respectively a convenient access to the new 3-(dimethylamino)-1,2,4,3-triazaphospholines and 1,2,4,3-triazaphosphlines-3-oxide. The structure of all obtained products is confirmed by NMR (1 H, 31 P, 13C) and IR spectroscopy.

Variations in the Essential Oil Composition from Different Organs of Ruta chalepensis L. (Rutacea) Growing Wild in Tunisia

Abstract: The chemical compositions of essential oils of Ruta chalepensis L. (Rutaceae) collected from the South-East of Tunisia (Thoujene at 525 m altitude) were identified. The essential oils were extracted from the leaves, stems, and fruits by hydrodistillation and they were analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC-MS). Nineteen compounds were identified from the different plant organs, where ketones and esters constituted the main chemical classes. The most abundant compounds in the leaves and stems’ essential oils were 2-nonanone (16.7–22.1 %), octyl acetate (12.1–26.8 %) and 2-undecanone (27.9–37.7 %), while 2-nonanone (19.1 %) and 2-undecanone (58.4 %) were found to be major compounds in the fruits’ essential oil. Our findings suggest that R. chalepensis growing wild in South-East of Tunisia seems to be a new chemotype.

Synthesis and Evaluation of New Bis‐1,3,4,2‐triazaphospholinoalkane Derivatives as In Vitro α‐Amylase and Lipase Inhibitors

A series of new 1,ω‐bis‐(5‐alkyl‐2‐oxide‐3‐tosyl‐1,3,4,2‐triazaphospholino)alkanes 2 and 3 were prepared in good yields by the treatment of 1,ω‐bis‐(1‐tosylamidrazone)alkanes 1 with two molar equivalents of phosphoryl trichloride and phenylphosphonic dichloride, respectively. All the newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, 31P NMR, and elemental analysis. All the new compounds were screened for their inhibitory effect on the key enzymes related to diabetes and obesity, as α‐amylase and lipase. The in vitro study revealed that these alkane derivatives exert an inhibitory action against these key enzymes, especially 2b with an IC50 of 16 μg/mL against α‐amylase and lipase. Overall, the findings of the current study indicate that 2d exhibits attractive properties and can therefore be considered for future application in the development of antidiabetic and hypolipidemic drugs.

Characterization of Aromatic Compounds and Antioxidant Activity of Essential Oils from Tunisian Pituranthos tortuosus (Coss.) Maire (Apiaceae)

Abstract The essential oils compositions from different parts of Pituranthos tortuosus (Coss.) Maire collected at the flowering and the fruiting stages were investigated. The essential oils were extracted by hydrodistillation and analyzed by GC/FID and GC/MS techniques. A total of 53 compounds representing 95.7 to 99.6% of the total oil were identified, showing large qualitative and quantitative differences. The analyzed oils were characterized by a very high percentage of monoterpenes, in which the monoterpene hydrocarbons constituted the predominant class especially in the stems (79.1%) at the fruiting stage. The major compounds in the flowers and the seeds were dillapiole (33.9; 37.2%), limonene (14.9; 10%), sabinene (8.8; 10.9%) and 3- n-butylphtalide (14.2; 6.7%), respectively. The antioxidant activity of the essential oils was evaluated by the metal (Fe2+) chelating and Fe3+ reducing power assays. The stems and seeds essential oils showed an important reducing power (EC50 : 0.06-0.08 mg/ml). Our findings demonstrated that P. tortuosus growing wild in the South-East of Tunisia could be considered as an interesting source of natural antioxidants.

Fruits of Ruta chalepensis L. (Rutaceae) as a Source of 2-undecanone

Abstract The chemical composition of the essential oils of spontaneous aromatic plants is severely affected by edapho-climatic factors as well as the development stage of the plant. Therefore, the objective of the present work is to better understand the essential oil quality of Ruta chalepensis L. (Rutaceae), a medicinal plant widely used in folk medicine, collected at the fruiting stage from two populations of south-east of Tunisia. Each organ of Ruta chalepensis (leaves, stems, and fruits) was hydrodistillated by a Clevenger-type apparatus. Gas chromatography-flame ionization detector (GC-FID) and GC-mass spectrometry (GC-MS) analyses of the essential oils resulted in the identification of nineteen compounds, where esters and ketones represented the main chemical classes. The major compounds in the essential oils of leaves and stems were 2-undecanone (23.0-37.7%), 2-nonanone (16.7-23.0%) and octyl acetate (11.0-26.8%), whereas 2-undecanone (57.5-58.4%) and 2-nonanone (19.0-23.3%) were found to be the most abundant compounds in the fruits essential oil.