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Variation in antioxidant activity and phenolic content in different organs of two Tunisian cultivars of Olea europaea L.

100%

Brahmi F., Mechri B., Dhibi M., Hammami M.

Acta Physiologiae Plantarum

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2014

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tom 36

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nr 01

This paper reports a comparative study based on the antioxidant compounds, total phenol content and antioxidant activities of leaves, stems and fruits from the main Tunisian cultivars, ‘chetoui’ and ‘chemchali’, grown in two different locations, north and south of Tunisia. The repartition of olive phenolic compounds was organ dependant. Therefore, the HPLC analysis indicated that the olive organs from the northern cultivar had the highest level of hydroxybenzoic acids, hydroxycinnamic acids and flavonoid class; which were less in the southern cultivar. Principal component analysis of the phenolic compounds showed discrimination between methanol extracts of the organs olive. Significant differences (p ˂ 0.05) in the levels of phenols, orthodiphenols and flavonoids were found between cultivars and between organs. Antioxidant activities of the methanolic extract from aerial parts of the two studied cultivars were evaluated using 2,2-diphenyl-1-picrylhydrazyl and 2,2' -azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assays. In all tests, methanolic extracts of different olive parts showed higher antioxidant activity. These results can be used to discriminate and to characterize the ‘chetoui’ and ‘chemchali’ aerial parts.

2

Antioxidant activities of the volatile oils and methanol extracts from olive stems

88%

Brahmi F., Mechri B., Flamini G., Dhibi M., Hammami M.

Acta Physiologiae Plantarum

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2013

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tom 35

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nr 04

This study was designed to examine the chemical composition and antioxidant activities of the volatile oils and methanol extracts of Olea europaea L. (cvs) chemlali and neb jmel stems. GC and GC–MS analyses of the volatile oils resulted in the identification of 38 and 35 compounds, representing 91.1 and 87.4 % of the volatile oils. Phenylethyl alcohol was found in the volatile oil of each cultivar, which was also the major volatile component of cv. chemlali and cv. neb jmel stems. Besides benzyl alcohol, methyl salicylate and 3-ethenylpyridine were the main volatile compounds of cv. chemlali, while nonanal, 3-ethenylpyridine and benzyl alcohol of cv. neb jmel stems were also the main constituents. Significant differences were also found in total tannin contents among two cultivars, representing 8.10 mg CEQ/g DW in cv. chemlali and 20.47 mg CEQ/g DW in cv. neb jmel. The highest contents of total phenols and o-diphenols were observed in stems extracts of cv. neb jmel (78.26, and 9.56 mg/100 g, respectively). The HPLC profiles for methanol extracts from stems of cv. chemlali and cv. neb jmel showed that oleuropein, vanillic acid and gallic acid were the predominant free phenolic compounds. Antioxidant activities of the volatile oils and the methanolic extract from stems parts were evaluated by DPPH and ABTS+ radical-scavenging activity assays. In all tests, methanolic extracts obtained from stems parts showed better antioxidant activity than volatile oils. Principal components analysis of the phenolics content and antioxidant activities showed discrimination between methanol extracts of the two cultivars.

3

Fatty acid composition in relation to the micro-organisms in the Sfax solar saltern, Tunisia

76%

Ayadi H., Elloumi J., Guermazi W., Bouain A., Hammami M., Giraudoux P., Aleya L.

Acta Protozoologica

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2008

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tom 47

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nr 3

189-203

4

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Phytochemical characterisation and bioactive properties of Solanum sodomaeum L. fruits at two stages of maturation

76%

Ouerghemmi I., Farhat M. B., Harbeoui H., Hammami M., Hamdaoui G., Marzouk B., Tounsi M. S.

Herba Polonica

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2018

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tom 64

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nr 3

Introduction: Solanum sodomaeum L. has been observed to have several medicinal properties, in particular, in the treatment of several types of human skin cancer. Objective: The influence of the maturation stage of S. sodomaeum fruits on the total lipid contents, fatty acid profiles, essential oil yields and compositions, as well as the antibacterial and antioxidant activities of the essential oils, was investigated. Methods: The fatty acid and essential oil constituents were identified using gas chromatography (GC) and GC–mass spectrometry (GC–MS). The antioxidant properties of essential oil and vegetal oil were assessed using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging and reducing power assays. The antibacterial ac-tivity of essential oil was tested using the disc diffusion assay for resistance in human pathogenic bacteria. Results: Mature fruits showed higher total lipid content (17%) and were characterised by polyunsaturated fatty acids (53.87%), represented mainly by linoleic acid (53.11%). Similar yields of essential oils were detected for immature (0.43%) and mature (0.45%) fruits. Tetrahydronaphthalene (41.79%) was detected as the major essential oil component at the immature stage versus dihydrocoumarin pentane (18.27%), hexadecanoic acid (17.43%) and 2-undecanone (13.20%) in mature fruits. The DPPH test showed that essential oils had better antioxidant properties; however, the vegetal oils showed better performance in the reducing power assay. Moreover, the essential oil of S. sodomaeum mature fruits was active against bacterial strains. Conclusions: S. sodomaeum fruits could be a valuable source of natural antioxidants and antibacterial agents.

5

Improving performance of olive trees by the enhancement of key physiological parameters of olive leaves in response to foliar fertilization

64%

Tekaya M., El-Gharbi S., Mechri B., Chehab H., Bchir A., Chraief I., Ayachi M., Boujnah D., Attia F., Hammami M.

Acta Physiologiae Plantarum

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2016

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tom 38

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nr 04

6

Biochemical characterization of fennel (Ferula communis L.) different parts through their essential oils, fatty acids and phenolics

64%

Rahali F. Z., Lamine M., Rebey I. B., Wannes W. A., Hammami M., Selmi S., Mliki A., Sellami I. H.

Acta Scientiarum Polonorum. Hortorum Cultus

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2021

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tom 20

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nr 1

Ograniczanie wyników

Variation in antioxidant activity and phenolic content in different organs of two Tunisian cultivars of Olea europaea L.

Antioxidant activities of the volatile oils and methanol extracts from olive stems

Fatty acid composition in relation to the micro-organisms in the Sfax solar saltern, Tunisia

Phytochemical characterisation and bioactive properties of Solanum sodomaeum L. fruits at two stages of maturation

Improving performance of olive trees by the enhancement of key physiological parameters of olive leaves in response to foliar fertilization

Biochemical characterization of fennel (Ferula communis L.) different parts through their essential oils, fatty acids and phenolics