A new process for green extraction of essential oil from Eucalyptus oleosa: Microwave-assisted hydro distillation

In this work, the potential of microwave-assisted Hydro-distillation (MAHD) process was evaluated for the extraction of Tunisian Eucalyptus oleosa essential oils and the results were compared with those of the conventional Hydro-distillation (HD) in terms of extraction time, essential oil yield, chemical composition, energy consumption and environmental impact.Results show that essential oil obtained by MAHD was quantitatively like those obtained by HD, but MAHD offered net advantages in terms of saving energy and extraction time (90 min against 25 min). In addition, the quality of the essential oil is improved thanks to a 50.42% increase in oxygenates compounds. Scanning electron microscopy (SEM) analyses of E. oleosa tissue structure before and after extraction were used as confirmation that microwave technique was faster than conventional HD. This study demonstrates the effectiveness of MAHD as a quick, green and efficient alternative for the extraction of essential oil from medicinal plants

Valorization of Date Palm Wastes by Lignin Extraction to be Used for the Improvement of Polymeric Membrane Characteristics

This work aimed to valorize Date Palm Wastes (DPW) by the extraction of lignin and its application for polymeric membrane modification. Lignin was extracted from five types of DPW (date palm kernel, leaflet, pedicel, palm frond, and fibrilium) using the Klason method. Following DPW characterization, we remark the highest amount of extractives content in the leaflet sample (10.07 %) and the lowest in the fibrilium sample (6.51 %). The ash content ranged from 1.56 % for fibrilium to 7.96 % for palm frond. After extraction, the lignin yield was in the range of 22–32 %. The extracted lignins were characterized by Infrared and Ultraviolet–visible spectroscopy. All extracted lignins provide a high concentration of (-OH) group. Besides, both syringyl and guaiacyl are present in the extracted lignins with a slightly more syringyl unit. The extracted lignins were added to the polymeric solution, prepared from waste plastic, to produce membranes. These membranes showed improved hydrophilicity marked a decrease in the contact angle of 28 % when the lignin concentration increased from 0.125 to 0.5 %. In addition, the membrane porosity increased with the use of the extracted lignins as an additive

Polyploidy induction of Tunisian Trigonella foenumgreaum L. populations

Polyploidy plays an important role in plant evolution and constitutes an important mechanism of diversification and creation of genetic variability. Artificial polyploidy can be induced using the colchicine. The aim of this study was to determine the Trigonella foenum-greacum (2n= 16)  population which resists better to colchicine treatment and which has the highest rate of polyploid formation among 38 populations collected from different Tunisian regions. The comparative study between treated and control plants showed significant increases (p < 0.05) for the parameters survival rate, rate of malformed leaves appearance, stem height and seeds number by pod. The 38 treated populations showed significant variations (p < 0.05) between them for the parameters survival rate, branches number, stem height and seeds number by pod. Results also showed that treatment of the shoot meristem by colchicine allowed to obtain diploid (2n= 16) and mixoploid plants having mixoploid branches (4n = 32 and 2n= 16) and branches entirely tetraploid (4n = 32). The obtained rate of mixoploidy was 65.79% of treated plants. Among the 38 analyzed fenugreek populations, the population 15 of Menzel Temime presented the highest rate of mixoploids formation and survival rate to colchicine treatment.Key words: Fenugreek, induction of chromosome doubling, mixoploidy, colchicine, Tunisia

Fatty acids and triacylglycerols composition from Tunisian Acacia species seed oil

AbstractRecently, plant seeds that have not been enough explored and exploited are cheap sources of a lot of natural molecules for industrial applications. The aim of the present study was to evaluate for the first time the composition of fatty acids and triacylglycerols (TAG) of mature unexploited seeds of some Acacia species (Acacia cyclops, Acacia ligulata and Acacia salicina) harvested in Tunisia in order to reveal their potential for human consumption.Results showed that, Acacia seed oils were mainly unsaturated (more than 71%). The polyunsaturated fatty acids were the major fractions (52–68%) with the linoleic acid as the major fatty acid (more than 52%), followed by oleic acid (15–27%) as monounsaturated fatty acid. The TAG composition was significantly different among the three Acacia species. PLL, PLO, LnLO, OLL, OOL, and OOO were the major forms. Acacia seed oil could be used as potential source of oil with high industrial value; nevertheless in vivo tests are essential to confirm its safety before use

Analysis of agromorphological diversity of southern Tunisia faba bean (Vicia faba L.) germplasm

Forty two faba bean landraces (traditional farmers’ varieties) (Vicia faba L.) from southern Tunisia, belonging to 8 oasis agro-ecosystems were assessed using morphological descriptors. The studied descriptors focused on morpho-phenological and morpho-agronomical traits. The data obtained is extracted on the basis of 35 descriptors of 42 populations from 8 localities, at a rate of 30 replications (plants) per population, in totality of 1260 individuals. The data underwent an analysis of variance and a multivariate analysis. Significant differences among populations for the thirty five descriptors were observed. The multivariate analysis performed on averages of all parameters revealed eight main groups, and variation within the same oasis agro-ecosystems was extremely important. Particularly, the group of ‘Tozeur’ made up of five populations (P38, P39, P40, P41 and P42), and the group of ‘Medenine’ composed of seven populations (P19, P20, P21, P22, P23, P24 and P25) showed a special characters than the other populations especially for seedling characters. The geographical location did not seem to be the main factor structuring the variability of the studied landraces. There proved to be substantial phenotypic variability in the Tunisian faba bean germplasm.Keywords: Diversity analysis, germplasm, faba bean (Vicia faba L.), oasis agro-ecosystems, Southern Tunisi

Phytochemical Profiles, in vitro Antioxidants, and Anti-inflammatory Activities of Flowers and Leaves of Lantana camara L. Grown in South of Tunisia

The current study assesses the photochemical profiles, the in vitro antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), reducing power ferric and silver nanoparticule) and anti-inflammatory activity of Lantana camara L. leaves and flowers collected from the South of Tunisia. Bioactive extracts of two organs were prepared through an ultrasound-assisted extraction in ethanol. Herein, multivariate statistical analysis was performed to define the relationship between biological activities and the bioactive molecules content and composition. Phytochemical profiling showed higher phenolic and flavonoids contents in leaves extracts than in those obtained from flowers, while the condensed tannins was absent in both organs. LC-MS analysis identified 16 and 15 phenolic compounds from flowers and leaves extracts, respectively. The flowers extract was especially rich in Kaempferol, luteolin-7-O-glucoside, quinic acid and apigenin-7-O-glucoside. Kaempferol, luteolin-7-O-glucoside, quinic acid and syringic acid were identified as the prevalent compounds in leaves extract. The latter exhibited the highest DPPH and ABTS radical scavenging potentials. Whereas flowers extracts revealed the highest reducing potential of ferric and silver ions. However, the leaves and flowers extracts are unable to protect bovine serum albumin (BSA) from thermal denaturation. Furthermore, significant correlations (p < 0.05) were recorded between phytochemical profile and biological activities, as well as between different antioxidant studied assays. The obtained results present practical data for the potential application of L. camara as a sustainable source of multi-functional molecules in food and medicinal industries

Polysaccharides from Tossa jute (Corchorus olitorius L.) leaves: Extraction, antioxidant and antibacterial activities

The biological proprieties of mucilaginous polysaccharides (PSc) extracted from Tossa jute leaves (Corchorus olitorius  L.) using an ethanol precipitation method were studied. The results showed that PSc had higher total polyphenols and flavonoids and greater antioxidant activities. At 1.5 mg/ml PSc, the antioxidant activities were about 90% against 1,1-diphenyl-2-picryl hydrazyl radical (DPPH•) and 78% against lipid peroxidation. The PSc with a FRAP assay at the same concentration showed an effective protection against hydroxyl radicals and DNA breakage. Furthermore, the extracted PSc had a wide spectrum of antibacterial activities against all bacteria tested (Gram+ and Gram-). The overall data suggested that this natural PSc may be used as a competitive antioxidant and antimicrobial additive in food and in medicinal preparations

Effect of genotype and extraction method on polyphenols content, phenolic acids, and flavonoids of olive leaves (Olea europaea L. subsp. europaea)

Polyphenol’s extraction varied according to various factors. In this study, the effect of genotype and method of polyphenols extraction were investigated using leaves of two cultivated and two wild olive varieties and four hydromethanolic extraction methods. Quantitatively, significant differences were observed according to the extraction method, the genotype, and the interaction genotype-method of extraction. The heat reflux extraction showed the highest polyphenols content in wild olive leaves having an amount of 841.17 mg GAE/100 g DM. The qualitative phytochemical examination using high performance liquid chromatography (HPLC) of olive leaves showed some significant differences of phenolic compounds between genotypes. For the same oleaster genotype, the extraction method seemed to influence qualitatively the polyphenols profiles. The quinic acid was the dominant phenolic acid and the luteolin-7-O-glucoside was the major flavonoid observed in wild olive leaves having, respectively, 618.24 and 3211.44 mg/kg DM. The quinic acid has an amount of 400.15 and 275.39 mg/kg and the luteolin-7-O-glucoside has an amount of 2059.62 and 1214.49 mg/kg in cultivars leaves. The extraction by Soxhlet of wild olive leaves showed the highest quinic acid (1085.80 mg/kg DM) and luteolin-7-O-glucoside (3720.15 mg/kg DM) amounts. The hydromethanolic extraction assisted by Soxhlet of wild olive leaves constituted the optimal method to obtain high polyphenols contents enriched with phenolic acids and flavonoids

Isolation and Characterization of Novel Microsatellite Markers in Pomegranate (Punica granatum L.)

Pomegranate (Punica granatum L.) has been cultivated from ancient times for its economic, ornamental and medicinal properties globally. Here, we report the isolation and characterization of 12 polymorphic microsatellite markers from a repeat-enriched genomic library of Punica granatum L. The genetic diversity of these loci was assessed in 60 genotypes of Punica granatum L. All loci were variable: the number of polymorphic alleles per locus ranged from two to five (average 2.9). The observed and expected heterozygosities ranged from 0.15 to 0.87 and 0.29 to 0.65, respectively. The polymorphic information content ranged from 0.26 to 0.61 (average: 0.43). To the best of our knowledge, this is the first time that polymorphic microsatellite markers have been reported for P. granatum L. These new markers should allow studies of the population structure and genetic diversity of pomegranate to be performed in the future

Essential oils, chemical composition, and biological activities of Eucalyptus oleosa F. Muell. : A review

Many Eucalyptus species are growing in the border of oasis areas. Eucalyptus sp. are generally known for their richness in essential oils and their virtues and economic interests. However, the great taxonomic diversity affects the quantity and quality of these oils. This study is designed to summarize the chemical composition of Eucalyptus oleosa and their biological activities. The yield of essential oils in the leaves of this species varies from 0.45% to 6.7%. These oils contain many chemical compounds of which 1,8-cineole is the main component (15.31% – 89.4%) followed by α-pinene (1%– 24.7%).  Eucalyptus oleosa essential oils exhibited antioxidant, antibacterial, anti-fungal and insecticidal activities with high variability. This variability is associated to many factors such as subspecific diversity, geographical location, part of plant and essential oil’s extraction method