Fructooligosaccharides from Cynoglossum tubiflorus: Effect of the molecular size on their antidiabetic activity in high-fat diet and alloxan induced diabetic rats.

The use of acetylation followed by silica gel column purification allowed the isolation of eight fructooligosaccharides (FOS) from the ethanol extract of Cynoglossum tubiflorus roots. Each FOS was identified by analyzing its FT-IR, HRMS/MS and NMR data, including 1H, 13C and 2D NMR HH COSY, HMBC and NOESY. In diabetic rats treated with a series of FOS from Glc-(Fru)3 to Glc-(Fru)7, a significant inhibition of intestinal α-amylase was observed. This activity increases proportionally with the FOS molecular size. It was found that they delay the absorption of total cholesterol (TC), ldl-cholesterol (LDL-C) and increase HDL-cholesterol (HDL-C) in a molecular size-dependent manner. This inhibitory effect on the activity of the digestive enzyme causes a significant (p < 0.05) reduction in the level of glucose in the blood as an anti-diabetic action. The ethanolic extract (E.E) exerts a significant effect against α-amylase as well as antihyperglycemic and antihyperlipidemic actions, while its acetylation suppresses these effects. Therefore, this study demonstrates for the first time that pure FOS act as an efficient agent in preventing hyperglycemia and hyperlipidemia and that this action evolves in the same manner with their molecular size.

The sweet and embellishing Lycium arabicum Schweinf. ex Boiss. fruit oil: a potential source of essential ω-6 and ω-9 fatty acids, phytosterols, and carotenoids.

In our current phytochemical investigation on the Tunisian plant Lycium arabicum Schweinf. ex Boiss., we attempted to explore the oil obtained from its fruits. This oil was extracted by cold maceration with ethanol and was analyzed to estimate its sterol and fatty acid content. The physicochemical parameters of the oil were also examined. They were specified in terms of acid value (0.8 ± 0.01 mg KOH g-1 oil), peroxide value (10.9 ± 0.02 meq O2 kg-1 oil), saponification value (162.97 ± 0.03 mg KOH g-1 oil), chlorophylls (1.011 ± 0.03 mg kg-1 oil) and carotenoids (42.1 ± 0.05mg kg-1 oil). Gas chromatography analysis demonstrated that oleic (33.5%), palmitic (26.81%) and linoleic (21.51%) acids were the dominant fatty acids. Furthermore, the analysis of this oil with HPLC equipped with a differential refractometer detector (DRD) showed that Palmitic-Oleic-Oleic (21.10%) and Oleic-Oleic-Oleic/Palmitoleic-Palmitic-Palmitic (17.11%) are the main triacylglycerols in this oil. It was also found that this oil contains high levels of ß-sitosterol (31.51%), Δ-5-Avenasterol (25.17%), and Δ-7-Avenasterol (15.22%). Analysis of its spectroscopic features allowed us to deduce that this oil contains some sugars like glucose, sucrose, and fructose as well as several carotenoid pigments. From this perspective, Lycium arabicum fruits oil (LAFO) maybe regarded as a worthwhile product that deserves supplementary consideration and investigation as a potentially new multi-purpose candidate for agro-food as a sweetener and a beautifier, in addition to its extreme usefulness for cosmetic and medicinal applications owing to its richness in phytosterols and conservative pigments.

Effect of extraction procedures on the chemical structure, antitumor and anticoagulant properties of ulvan from Ulva lactuca of Tunisia coast.

The effect of extraction procedures on chemical composition, structural, antitumor and anticoagulant properties of the sulphated polysaccharide 'ulvan' from the green seaweed Ulva lactuca were investigated. The structural features of ulvans were carried out by FTIR and by one- and two- dimensional 1H and 13C NMR spectroscopic. The ulvans were mainly composed of rhamnose, xylose, and uronic acid. Chemical and spectroscopic analyses demonstrated that ulvans were constituted of (1→4)-ß-glucuronic acid, (1→3,4)-α-L-rhamnose-3-sulphate and (1→4)-α-xylose. The extraction procedures effect were observed in chemical structure, Mw and biological activities. Cytotoxic activity of enzymatic-chemical extract on cervical cancer cells (HeLa) (IC50 = 1000 µg/mL) was higher than on normal peripheral blood lymphocytes cells (PBL). Acid extracts promoted to reduce HeLa cells and to grow PBL cells. At high concentrations, acid extracts showed the highest APTT and TT clotting time. Antitumoral and anticoagulant activities of ulvans from Ulva lactuca promote their use as effective therapeutic agent.

UHPLC/HR-ESI-MS/MS Profiling of Phenolics from Tunisian Lycium arabicum Boiss. Antioxidant and Anti-lipase Activities' Evaluation.

This study was performed in the aim to evaluate nine different extracts from Tunisian Lycium arabicum for their total phenolic and total flavonoid contents, phytochemical analyses as well as their antioxidant and anti-lipase activities. The in vitro antioxidant property was investigated using three complementary methods (DPPH, ferric reducing antioxidant power (FRAP), and ß-carotene-linoleic acid bleaching assays) while anti-lipase activity was evaluated using 4-methylumbelliferyl oleate method. From all of the tested extracts the most potent found to be the polar MeOH extracts especially those of stems and leaves. In order to investigate the chemical composition of these extracts and possible correlation of their constituents with the observed activities, an UHPLC/HR-ESI-MS/MS analysis was performed. Several compounds belonging to different chemical classes were tentatively identified such as rutin and kampferol rutinoside, the major constituents of the leaves, and N-caffeoyltyramine, lyciumide A, N-dihydrocaffeoyltyramine as well as fatty acids: trihydroxyoctadecadienoic acid and hydroxyoctadecadienoic acid isomers were detected abundantly in the stems. These results showed that the MeOH extracts of stems and leaves of L. arabicum can be considered as a potential source of biological active compounds.

Hexane Extract of Echinops spinosissimus Turra subsp. spinosus from Tunisia: A Potential Source of Acetylated Sterols - Investigation of its Biological Activities.

The hexane extract of Echinops spinosissimus Turra subsp. spinosus flower heads was analyzed for its fatty acid and sterol composition. Its physicochemical characteristics were also studied. The saponification, iodine and peroxide values were determined as 255 mg KOH/g, 42.57 g I2 /100 g and 110 m equiv. O2 /kg of oil, respectively. The oleic (C18:1; 61.14%), palmitic (C16:0; 21.36%) and linoleic (C18:2; 10.45%) acids were the dominant fatty acids. This extract was also found to contain high levels of ß-sitosterol and stigmasterol (44.97% and 34.95% of total sterols, respectively). On the other hand, the identification of terpenoid compounds was investigated by using GC/MS, which revealed fourteen major terpenoids mainly taraxasterol, lupeol, pseudotaraxasterol, lup-22(29)-en-3-yl acetate, taraxasteryl acetate, α-amyrin, ß-amyrin, pseudotaraxasteryl acetate, hop-20(29)-en3-ß-ol, α-amirenone, along with ß-sitosterol and stigmasterol. Moreover, we have evaluated the in vitro antibacterial and antifungal activities of the unsaponifiable matter and a fraction isolated from this extract. These activities were conducted using the diffusion disc methods and broth microdilution assay. The resulted fraction from this extract showed the highest antibacterial activity with significant minimum inhibitory concentrations (MIC) values 125.0 µg/ml against Staphylococcus aureus, Micrococcus luteus and Bacillus cereus. However, it did exhibit no substantial antifungal activity.