Chemical Composition and In Vitro Evaluation of Antimicrobial, Antioxidant and Antigerminative Properties of the Seed Oil from the Tunisian Endemic Ferula tunetana Pomel ex Batt.

Essential oil of the seeds from the endemic Tunisian plant Ferula tunetana Pomel ex Batt. was analyzed for its chemical composition and screened for its antimicrobial, antioxidant and antigerminative properties. The chemical composition of the isolated oil is reported for the first time. According to the GC/FID, GC/MS and 13 C-NMR analysis results; 18 compounds were identified accounting for 84.6% of the total oil. The chemical composition of this essential oil was characterized by the presence of a high proportion of monoterpene hydrocarbons (77.3%) followed by oxygenated sesquiterpenes (4.1%) and sesquiterpene hydrocarbons (3.2%). α-Pinene (39.8%), ß-pinene (11.5%) and (Z)-ß-ocimene (7.5%) were the predominant compounds. Moreover, the isolated oil was tested for its antimicrobial activity using the disc-diffusion and the microdilution assays against six Gram-positive and five Gram-negative bacteria as well as towards two Candida species. The isolated oil was tested also for its antioxidant activity against DPPH, ABTS, O2∙ and hydrogen peroxide (H2 O2 ), and for its antigerminative potential. It was found that it exhibited interesting antimicrobial activity against Salmonella typhimurium LT2 DT104 (inhibition zone (IZ) 16.2 ± 1.0 mm) and Bacillus cereus ATCC 14579 (IZ 15.8 ± 1.0 mm). However, it exerted a moderate antioxidant activity against H2 O2 (IC50 78.2 ± 2.98 µg/ml) and towards O2∙ (IC50 89.2 ± 3.82 µg/ml). The antigerminative effect of this oil was also evaluated in this work. Results showed a toxic effect.

Protective Effects of α-Tocopherol, γ-Tocopherol and Oleic Acid, Three Compounds of Olive Oils, and No Effect of Trolox, on 7-Ketocholesterol-Induced Mitochondrial and Peroxisomal Dysfunction in Microglial BV-2 Cells.

Lipid peroxidation products, such as 7-ketocholesterol (7KC), may be increased in the body fluids and tissues of patients with neurodegenerative diseases and trigger microglial dysfunction involved in neurodegeneration. It is therefore important to identify synthetic and natural molecules able to impair the toxic effects of 7KC. We determined the impact of 7KC on murine microglial BV-2 cells, especially its ability to trigger mitochondrial and peroxisomal dysfunction, and evaluated the protective effects of α- and γ-tocopherol, Trolox, and oleic acid (OA). Multiple complementary chemical assays, flow cytometric and biochemical methods were used to evaluate the antioxidant and cytoprotective properties of these molecules. According to various complementary assays to estimate antioxidant activity, only α-, and γ-tocopherol, and Trolox had antioxidant properties. However, only α-tocopherol, γ-tocopherol and OA were able to impair 7KC-induced loss of mitochondrial transmembrane potential, which is associated with increased permeability to propidium iodide, an indicator of cell death. In addition, α-and γ-tocopherol, and OA were able to prevent the decrease in Abcd3 protein levels, which allows the measurement of peroxisomal mass, and in mRNA levels of Abcd1 and Abcd2, which encode for two transporters involved in peroxisomal ß-oxidation. Thus, 7KC-induced side effects are associated with mitochondrial and peroxisomal dysfunction which can be inversed by natural compounds, thus supporting the hypothesis that the composition of the diet can act on the function of organelles involved in neurodegenerative diseases.

New bioactive dihydrofuranocoumarins from the roots of the Tunisian Ferula lutea (Poir.) Maire.

A phytochemical investigation of the roots of Ferula lutea (Poir.) Maire led to the isolation of new dihydrofuranocoumarins as two inseparable isomers, (-)-5-hydroxyprantschimgin 1 and (-)-5-hydroxydeltoin 2, together with eight known compounds, (-)-prantschimgin 3, (-)-deltoin 4, psoralen 5, xanthotoxin 6, umbelliferone 7, caffeic acid 8, ß-sitosterol 9 and stigmasterol 10. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D and 2D NMR experiments and mass spectroscopy analysis, as well as by comparison with literature data. The anti-acetylcholinesterase and cytotoxic effects of the isolates and antioxidant activities of the mixture (1+2) were also evaluated in this work. Results showed that the mixture (1+2) has the most cytotoxic activity with IC50 values 0.29±0.05 and 1.61±0.57µM against the cell lines HT-29 and HCT 116, respectively. The greatest acetylcholinesterase inhibitory activity (IC50=0.76±0.03) was exhibited by the xanthotoxin 6. In addition, the mixture (1+2) was investigated for its antioxidant activity and showed IC50 values 18.56, 13.06, 7.59, and 4.81µM towards DPPH free radical scavenging, ABTS radical monocation, singlet oxygen and hydrogen peroxide, respectively.

Glaucasides A-C, three saikosaponins from Atriplex glauca L. var. ifiniensis (Caball) Maire.

From the roots of Atriplex glauca L. var. ifiniensis (Caball) Maire (syn. of Atriplex parvifolia Lowe var. genuina Maire), three new saikosaponins designated as glaucasides A-C (1-3) were isolated together with the known 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-galactopyranosyl-saikogenin F (4). The structures of the new compounds were elucidated by extensive analysis of one-dimensional and two-dimensional NMR spectroscopy, FABMS, HR-ESIMS and chemical evidence as 13ß,28-epoxy-16ß,21ß-dihydroxyolean-11-en-3ß-yl O-ß-D-[2-O-sulfate]-glucopyranosyl-(1 → 2)-α-L-arabinopyranoside (1), 13ß,28-epoxy-16ß,21ß-dihydroxyolean-11-en-3ß-yl O-ß-D-[2-O-sulfate]-glucopyranosyl-(1 → 2)-α-L-arabinopyranosyl 21-O-{4-(secbutylamido)-butanoyl ester} (2) and 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-galactopyranosyl saikogenin G (3). The cytotoxic activities of these compounds were evaluated against the HT-29 and HCT 116 human colon cancer cell lines.

Two new sesquiterpene derivatives from the Tunisian endemic Ferula tunetana Pom.

A new sesquiterpene ester, tunetanin A (1), a new sesquiterpene coumarin, tunetacoumarin A (2), together with eight known compounds, i.e., coladin (3), coladonin (4), isosmarcandin (5), 13-hydroxyfeselol (6), umbelliprenin (7) propiophenone (8), beta-sitosterol (9), and stigmasterol (10), were isolated from the roots of Ferula tunetana. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D- and 2D-NMR experiments and MS analysis, as well as by comparison with published data. The cytotoxicity of compounds 1-7 towards two human colon cancer cell lines, HT-29 and HCT 116, was evaluated. Compounds 3, 4, and 6 showed weak cytotoxic activities.

Flower and root oils of the tunisian Daucus carota L. ssp. maritimus (Apiaceae): integrated analyses by GC, GC/MS, and 13C-NMR spectroscopy, and in vitro antibacterial activity.

The essential oils from flowers and roots of Daucus carota L. ssp. maritimus were obtained by hydrodistillation and analyzed by combination of GC, GC/MS, and (13)C-NMR. The chemical composition of the flower and root oils of this subspecies is reported here for the first time. Thirty-two and six compounds were identified in flower and root oils, respectively. A remarkable difference was found between the constituent percentages of the two organs. The chemical composition of the essential oil from flowers was characterized by a high proportion of monoterpene hydrocarbons (68.4%) and belonged to the sabinene (4; 51.6%) chemotype. The oxygenated monoterpenes represented the second major fraction of the same oil among which terpinen-4-ol (11.0%) was the predominant compound. Root oil exhibited a surprisingly different composition. Phenolic derivatives (76.3%), myristicin (31; 29.7%), and dillapiole (32; 46.6%) constituted the main fraction. The antibacterial effect resulted in the inhibition of a series of common human pathogenic bacteria, and of some clinically and environmentally isolated strains with significant MIC and MBC values.

Chemical composition and in vitro evaluation of antimicrobial and anti-acetylcholinesterase properties of the flower oil of Ferula lutea.

The present work describes the chemical composition and evaluates the antimicrobial and the anti-acetylcholinesterase properties of the flower oil from the Tunisian Ferula lutea obtained by hydrodistillation and analyzed by combination of GC/FID and GC/MS. The chemical composition of the flower oil of this species is reported for the first time. Seventeen compounds were identified accounting for 94.3% of the total oil. The chemical composition of this essential oil was characterized by a high proportion of monoterpene hydrocarbons (80.4%) among which delta-3-carene (31.2%) and alpha-pinene (25.8%) were the predominant compounds. The oxygenated monoterpenes represent the second major fraction (12.0%), 2,3,6-trimethylbenzaldehyde (10.9%) being the predominant one. Furthermore, the isolated oil was tested for its antimicrobial activity using the disc-diffusion and the microdilution assays against six Gram-positive and five Gram-negative bacteria as well as towards eight Candida species. It was found that flower oil of F. lutea exhibited interesting antibacterial and anticandidal activity (MIC = 39 mcirog/mL against Escherichia coli, Staphylococcus aureus and S. epidermidis and MIC = 156 microg/mL against Candida albicans). The anti-acetylcholinesterase effect of this oil was also evaluated in this work. Results showed that this oil exhibits significant activity (IC50 =70.25 +/- 5.41 microg/mL).

Chemical composition and in vitro evaluation of antioxidant and antibacterial activities of the root oil of Ridolfia segetum (L.) Moris from Tunisia.

The present work describes the chemical composition and evaluates the antibacterial and the antioxidant properties of root oil from Ridolfia segetum, a traditional medicinal plant widely distributed in Tunisia. The essential oil, analysed by combination of GC, GC/MS and (13)C-NMR, was dominated by dillapiole (47.4%) and myristicin (19.2%). The antioxidant potential of the essential oil was evaluated using the 2,2'-diphenyl-1-picrylhydrazyl free radical scavenging method. The phenylpropanoid-rich root oil possesses good antioxidant properties (IC(50) = 38 mg mL(-1)). The essential oil was evaluated for its antibacterial activity using the microdilution assay, resulting in the inhibition of a number of common human pathogenic bacteria as well as of some clinical and environmental isolated strains. The minimum inhibitory concentrations of the essential oil varied between 1.25 and 5 mg mL(-1) and the minimum bactericidal concentrations were superior to 5 mg mL(-1) of oil for most strains. These results may suggest that the root oil of R. segetum possesses compounds with antibacterial and antioxidant capacities, and therefore can be explored as a natural preservative ingredient in food and/or for pharmaceutical preparations.