Identification of a naturally occurring 2, 6-bis (1.1- dimethylethyl)-4-methylphenol from purple leaves of the halophyte plant Mesembryanthemum crystallinum

2, 6-Bis (1.1-dimethylethyl)-4-methylphenol (BHT) is a synthetic antioxidant used generally for food, cosmetics and pharmaceuticals. The leaf extract from the halophyte plant, Mesembryanthemumcrystallinum, was fractionated by using semi-preparative HPLC. The different fractions were tested for their antioxidant activity using DPPH method. One fraction exhibited a high level of antioxidant activity.The molecule responsible for this antioxidant activity was identified as 2, 6-bis (1.1-dimethylethyl)-4-methylphenol) by gas chromatography/mass spectroscopy (GC/MS)

Effect of phosphorus limiting on phytase activity, proton efflux and oxygen consumption by nodulatedroots of common bean (Phaseolus vulgaris)

This work intended to measure the nodulated-roots oxygen consumption, proton efflux and phytase activity in 2 lines of common bean (Phaseolus vulgaris) (115, 147) at 2 levels of P supply. Rooted seedlings were inoculated with Rhizobium tropici CIAT 899 in hydroaeroponic cultivation under glasshouse. Phosphorus was supplied as KH2PO4 at 15 and 250 ìmol pl-1 week-1 (15P and 250P, respectively). Our results showed that plant growth nodulation and symbiotic nitrogen fixation were significantly affected by P limiting (15P) for the both lines, but this adverse effect was more pronounced in 147 than in 115. For the both lines, the phytase activity, higher in roots than in nodules, was significantly increased by P limiting, but 115 maintained higher values as compared to 147 line. Incotyledons, the phytase activity was higher in 115 than in 147. Phosphorus shortage increased the cumulated proton release only in 115, whereas it was lowered for 147. In this line, the proton release was linked to symbiotic nitrogen fixation. Under 15P, the proton efflux per unit of nodulated-root biomass was 25% greater for 115 than 147, suggesting that under P limitation, proton efflux may constitute an efficient way to increase P uptake in the tolerant line (115). 15P increased significantlynodulated-root O2 consumption per g nodule DW and nodule conductance, but to a higher extent in 147. As a whole, bean plants at P-deficient conditions increased the activity of phytases and proton efflux, thus maintaining the oxygen diffusion in nodules. This may represent an adaptive mechanism for N2- fixing legumes to respond to P deficiency, by increasing the utilisation and the uptake of phosphorus for symbiotic nitrogen fixation

Localization and composition of seed oils of Crithmum maritimum L. (Apiaceae)

The use of some halophytes for rehabilitation of salt affected area has been reported. Crithmum maritimum L. halophyte and apiaceae can tolerate high levels of salt. Their seed was endospermic and had a suitable size for oil extraction. The aim of this report is to localize the lipids in the seed and determine their oils composition. The results showed that the lipids were accumulated in endosperm tissue as oil globoids. The percentage of oils was 44.4% dry weight basis. The C. maritimum L. seed oil was rich with oleic acid (78.6%), low level of palmitic acid (4.8%) and non negligible amount of linoleic acid (15.4%). This composition is similar to olive oil and canola oil. These results confirmed the good quality of C. maritimum L. seed oils.Keys word: Halophytes; Crithmum maritimum L.; seed oils

Upshot of the ripening time on biological activities, phenol content and fatty acid composition of Tunisian Opuntia ficus-indica fruit

Total phenol content and the antioxidant activities of three cultivars of Opuntia ficus-indica (L.) Mill. were evaluated. The results show that the ecotypes were significantly different according to their fatty acid composition, antioxidant and antibacterial activity, as well as their polyphenol profiles. Rossa fruit collected in August exhibited the higher phenolic content (15.48 mg GAE g−1 DW) with a stronger antioxidant activity. Bianca fruit collected in August exhibited a lower phenolic content (3.13 mg GAE g−1 DW) together with the stronger antiradical activity (96.14%). The advantage of this ecotype was more discernible as compared to positive controls butylated  hydroxytoluene (BHT, 79.75%). Likewise, CpG chromatogram identification revealed also an important difference between the ecotypes on oleic and linoleic acids.Keywords: Opuntia ficus-indica, variability, phenol content, fatty acid, antioxidant activity.African Journal of Biotechnology Vol. 12(40), pp. 5875-588

Ultrasound-Assisted Extraction: Effect of Extraction Time and Solvent Power on the Levels of Polyphenols and Antioxidant Activity of Mesembryanthemum edule L. Aizoaceae Shoots

Purpose: To investigate the influence of extraction conditions assisted by ultrasound on the quality of extracts obtained from Mesembryanthemum edule shoots.Methods: The extraction procedure was carried out in an ultrasonic bath. The effect of two solvents (methanol and ethanol) and two extraction times (5 and 10 min) were evaluated on the basis of the phenolic content and antioxidant activity of the plant extract.Results: Significant variability in phenolic content and antioxidant activity, depending on the solvent (S), and to a lesser degree, extraction duration (D) and their interaction (S/D) were found. Methanol extract was significantly richer in total polyphenols than ethanol extract, their levels being 104.7 and 74.2 mg GAE.g-1DW, respectively. For the two solvents used, longer extraction duration yielded higher polyphenol content. The ethanol extract exhibited higher antioxidant activity than the methanol extract. Moreover, Also, the longer sonication duration (10 min) yielded extracts with higher antioxidant activities.Conclusion: The antioxidant capacity of M. edule is strongly influenced by the nature of the extracting solvent and the duration of sonication extraction.Keywords: Antioxidant activity, Extraction duration, Mesembryanthemum edule, Polyphenols, Sonicatio

Secondary metabolism responses in two Pisum sativum L. cultivars cultivated under Fe deficiency conditions

The present study was carried out to investigate the Fe deficiency effect on the secondary metabolism  responses in two Pisum sativum cultivars characterized by different tolerance to Fe deficiency. Previous study  investigating the physiological responses to Fe deficiency in these two pea cultivars showed that Kelvedon was  more tolerant than Lincoln. Both cultivars were grown in the absence or presence of Fe with the addition of bicarbonate for twelve days. Higher concentrations of phenols and flavonoids were observed in Fe-deficient  tissues of both cultivars; however, the increase was greater in the tolerant cultivar than in the susceptible  one. The activity of shikimate pathway enzymes tested was more enhanced in the tolerant cultivar. In  addition, lipid peroxidation and H2O2 concentrations were more increased in the susceptible cultivar when  compared with the tolerant one. Peroxidase activity was increased in the tolerant cultivar grown under  bicarbonate supply, while a considerable diminution was observed in the susceptible one, suggesting the  involvement of this antioxidant enzyme in the tolerance of pea to Fe deficiency. The lignifying peroxidases  activity was more decreased in Lincoln than in Kelvedon, especially in the presence of bicarbonate. Our data  suggest that the tolerance of Kelvedon was related to its ability to modulate the phenolic metabolism pathway and to enhance the antioxidant potentials.Key words: Iron deficiency, bicarbonate, phenolic metabolism, antioxidative enzymes, Pisum sativum

The phenolic compounds and compositional quality of Chétoui virgin olive oil: Effect of altitude

The differences in the chemical composition of virgin olive oils (VOO) obtained from trees of the Chetoui variety cultivated at different altitudes in Tunisia were evaluated. All samples were harvested using the same controlled procedures and were submitted to a controlled processing in the same laboratory mill. Several analytical parameters such as fatty acid composition, amounts of phenols; o-diphenols and pigments were analyzed. All these parameters showed an important effect on the fatty acids and phenols content of the oils. The total phenol content was positively correlated with the altitude, ranging from 817.33 mg/kg (403 m) to 131.91 mg/kg (10 m). However, the results of the regulated parameters in the potential quality classified all the analyzed oils into the ‘‘extra virgin’’ category.Key words: Orchard elevation, total antioxidant capacity, phenolic compounds, quality index

Phenolic nature, occurrence and polymerization degree as marker of environmental adaptation in the edible halophyte Mesembryanthemum edule

AbstractMesembryanthemum edule is an edible medicinal halophyte traditionally used to treat several human diseases. In this study, particular importance was attached to the influence of environmental conditions on phenolic composition and antioxidant activities of two M. edule provenances from contrasting climatic regions (Djerba and Monastir sampled from arid and superior semi-arid bioclimatic stages, respectively). Shoot phenolic content was evaluated using colorimetric method and its composition was identified by HPLC analysis with or without thiolysis. Antioxidant activities were assessed by five in vitro antioxidant systems. Results showed that the two M. edule provenances were significantly different according to their antioxidant activity as well as their polyphenol profiles. Indeed, plants from Djerba (lack of rainfall and long light hour periods) exhibited stronger antioxidant activity together with higher phenolic content. For instance, Djerba provenance shoots showed much lower IC50 (4.8μgml−1) and EC50 (80μgml−1) values for DPPH and Fe-reducing tests, respectively. In addition, the superiority of this provenance (Djerba) was more marked as compared to positive controls (BHT, BHA, and VitC). HPLC identification revealed also an important difference between the two provenances on major flavonoid components. This difference was confirmed by the mean degrees of tannin polymerization (DPn) which was higher in Djerba plants. These data suggest that M. edule adaptation to environmental stresses proceeds through induced particular phenol quality and DPn for the improvement of their antioxidant capacities to protect plant tissues against oxidative stress

Anatomy of the fruit of the halophyte Crithmum maritimum L. with emphasis on the endosperm structure and histochemistry

The halophytes are plants that can survive and reproduce under high salinity. They show high potentiality as new crops plant for biosaline agriculture. Crithmum maritimum L. (Apiaceae) is one of the promising halophytes. In this paper, the endosperm structure of the fruit of this oilseeds halophyte was investigated using scanning electrons microscopy (SEM), light microscopy (LM) and fluorescence microscopy (FM). The fruit was composed of a spongy outer coat, a secretory envelope, a thin endocarp reduced to a unicellular layer delimiting the endosperm and an embryo. The endosperm cell appeared limited by thick cell wall and filled with numerous reserve globoids. The histochemical test showed that the cell wall of the endosperm was rich of carbohydrates as revealed by PAS (periodic acid-schiffs). Within the endosperm cells, there were mainly lipid bodies and protein bodies. The starch grains were less abundant. The protein bodies enclose crystal globoids. The x-ray microanalysis revealed that the reserve globoids accumulated mostly Mg, K, Ca, S and P. Taken together, these results highlight the structural features, the biochemical composition and confirm the nutritional quality of C. maritimum L. fruit.Keys words: C. maritimum L., crystal globoids, the endosperm cells, histochemical test, protein bodies, x-ray microanalysis