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The aim of this comparative research was to determine the chemical composition, antioxidant and antibacterial activities of the methanolic extracts and essential oils (EOs) of Artemisia absinthium aerial parts from five different regions (Bizerte, Zaghouan, Kasserine, Gabes and Tozeur). The polyphenol and flavonoid contents significantly varied (P < 0.05) among the studied regions with maximal contents observed in Zaghouan. Based on the High Performance Liquid Chromatography results, quercetin and isorhamnetin were the main compounds and their percentages were region dependent. The methanolic extract of Zaghouan showed the highest scavenging ability of DPPH (IC50 = 31.46 ± 1.42 µg/mL). A. absinthium EOs from of the different regions were found to interestingly inhibit the growth of both Gram-negative and Gram-positive bacteria strains. The antibacterial effect was strongly related to the organoleptic EO quality. The EO of Zaghouan exhibited an important inhibitory effect with an inhibition zone estimated at 31 mm against Escherichia coli strain. The EO composition was obtained by GC-MS analysis showing the presence of thirty-five compounds. Camphor (49.70 ± 2.34 %) and chamazulene (25.41 ± 0.61 %) were the main constituents. These results suggested that the north regions have a high potential for selecting varieties rich on bioactive volatile and phenolic compounds. Resumen. El objetivo de esta investigación fue determinar y comparar la composición química, las actividades antioxidantes y antibacterianas de los extractos metanólicos y de los aceites esenciales (AE) de las partes aéreas de Artemisia absinthium de cinco regiones (Bizerta, Zaghouan, Kasserine, Gabes y Tozeur). Los contenidos de polifenoles y flavonoides variaron significativamente (P < 0,05) entre las regiones estudiadas con contenidos máximos observados en Zaghouan. De acuerdo con los resultados de la cromatografía líquida de alta resolución, la quercetina y la isorhamnetina fueron los compuestos principales y sus porcentajes dependieron de la región. El extracto metanólico de Zaghouan mostró la mayor capacidad secuestrante de DPPH (IC50 = 31.46 ± 1.42 µg mL-1). Se descubrió que los aceites esenciales de A. absinthium de las diferentes regiones inhibían de manera interesante el crecimiento de cepas de bacterias Gram-negativas y Gram-positivas. El efecto antibacteriano estuvo fuertemente relacionado con la calidad organoléptica del AE. El AE de Zaghouan exhibió un importante efecto inhibidor con un halo de inhibición estimado en 31 mm frente a una cepa de Escherichia coli. La composición de AE se obtuvo mediante análisis GC-MS y mostró la presencia de treinta y cinco compuestos. El alcanfor (49.70 ± 2.34 %) y el camazuleno (25.41 ± 0.61 %) fueron los principales constituyentes. Estos resultados sugirieron que las regiones del norte tienen un alto potencial para seleccionar variedades ricas en compuestos bioactivos volátiles y fenólicos.

This study aimed to determine the chemical composition of methanolic extracts of thirteen Eucalyptus species leaves cultivated in north east of Tunisia and their antioxidant activity was also inves...

This research aimed to study the chemical composition of Aloysia citrodora methanolic extract and its biological activities as an antioxidant, and its antibacterial, antifungal and anti-inflammatory activities based on four bioclimatic collection stages. The contents of total phenols, total flavonoids and total tannins were determined. Nine phenolic compounds were identified by LC-DAD–ESI-MS/MS. The major compound was acteoside, a phenylpropanoid which represented about 80% of the methanolic fraction in the various regions. The antioxidant activities of different locations were measured by different analytical assays, such as DPPH, ABTS and iron reducing power. The results showed that phenolic compounds and antioxidant activities varied with climatic and environmental factors. Moreover, there was a significant dependency between regions and biological activities. The use of a principal component analysis showed that there was a close relationship among phenylpropanoids, phenolic compounds and the studied biological activities.

A biochemical characterization and a geographic variability of Thymus capitatus L. essential oils were undertaken. Chromatographic analysis using gas chromatography-flame ionization detector and gas...

The aromatic medicinal plant Eucalyptus and its essential oils have been used since antiquity in folk medicine. The interest in this genus has increased remarkably over the last decade mostly because of their various biological activities. This study aimed to determine the chemical composition of essential oils of thirteen Eucalyptus species leaves and their antioxidant and antibacterial activities. Obtained results showed that E. maidenii had the highest essential oil yield (6.16 ± 1.55 %). Chemical composition (by GC/MS) was highly affected by the species factor (P

Thymus capitatus has traditionally been considered as an anthelmintic, antispasmodic, carminative, emmenagogue, expectorant, rubefactient, sedative, stimulant, and tonic. This work was carried out to determine total polyphenol and total flavonoids chemical composition of phenolics and to evaluate the antioxidant activities of the methanolic extract. Total phenolic contents were assayed using the Folin–Ciocalteu reagent, total flavonoid content was measured spectrophotometrically and phenolics were analyzed by reverse phase–high performance liquid chromatography. The 1,1-diphenyl-2-picrylhydrazyl and reducing power were calculated. Total phenols and total flavonoids varied significantly among the studied regions. Chromatographic analysis by reverse phase–high performance liquid chromatography showed that phenolic acids: tannic, gallic, chlorogenic hemihydrate, caffeic, syringic, ferulic, p-coumaric acid, and trans-cinnamic rosmarinic were the main compounds. The anti-radical activity was region-dependent a...

This study characterized the phenolic, aroma compositions, and antioxidant capacities of four Artemisia herba alba accessions collected from north and center regions in Tunisia in order to select valuable origin with optimal bioactive compounds production. The total polyphenol and flavonoid contents varied between accessions with maxima contents observed in center regions. Kaempherol, apigenin, naringenin, p-coumaric, trans-cinnamic, and caffeic acids were the most abundant compounds with percentage varying depending on the considered accession. Significant changes on essential oil yields (0.4–1.2%) were found between accessions and three different oil chemotypes were distinguished: camphor, fenchol/α-thujone, and α-thujone/camphor. Cluster analysis of volatile and phenolic compositions grouped the accessions on different groups. Antioxidant activities of extracts were found to be higher than essential oils for the four provenances. The results suggested that the center regions have high potential for sel...

The chemical composition of the essential oils of dried aerial parts of Lavandula dentata L. stoechas and L. multifida were analyzed by GC and GC-MS. A total of 52 compounds were identified representing 89.62 ± 9.56, 99.94 ± 9.88 and 98.21 ± 10.23 in Lavandula dentata L. stoechas and L. multifida oil, respectively. Essential oil yield varied significantly (P < 0.05) among the three studied Lavandula species and there were (1.96 ± 0.22 %), (1.62 ± 0.15 %) and (1.04 ± 0.11 %) on dry weight basis in L. dentata, L. multifida and L. stoechas, respectively. Essential oil extracted from aerial parts of L. dentata was dominated by linalool (47.30 ± 5.34 %), linalyl acetate (28.65 ± 3.26 %), bicyclogermacrene (3.40 ± 0.41 %), camphor (2.32 ± 0.28 %) and δ-terpineol (1.47 ± 0.16 %). Linalyl acetate (64.30 ± 7.55 %), linalool (20.25 ± 3.21 %) and β-thujone (8.97 ± 0.99 %) were the predominant compounds in L. stoechas essential oil. L. multifida oil was characterized by the predominance of linalool (50.05 ± ...

The volatile oil of coriander (Coriandrum sativum L.) obtained from the fruits by soxhlet-dynamic headspace (S-DHS), solvent extraction (SE), steam distillation (SD), hydrodistillation (HYD) and supercritical CO2 extraction (SC-CO2) were analyzed by GC-FID and GC-MS. The SC-CO2 offered a higher yield (4.5%, w/w) than the other used techniques. Among the identified constituents, linalool was the main compound whatever the employed extraction procedure in contrast to the remaining components which varied according to the isolation technique showing a strong effect of the method used on the composition of these minor compounds. SC-CO2 as compared to the other extraction techniques revealed its high efficiency in addition to the integrity saving of coriander fruit volatiles. Statistical analysis showed that all the detected and identified compounds were highly (P0.001) affected by the extraction technique used except the a-terpineol which appear stable. On the other hand, principal component analysis (PCA) revealed on the determination of one group represented by SC-CO2, S-DHS and HYD suggesting a similar essential oil composition. Obtained results show that, in Tunisian coriander essential oil, linalool was the main compound.