Characterization of Volatile Organic Compounds and Essential Oil Profile of Pittosporum tobira (Thunb.) W.T. Aiton Cultivated in Tunisia.

The chemical compositions of the essential oils (EOs) of roots, young and old leaves and stems, and flowers of Pittosporum tobira (Thunb.) W.T. Aiton cultivated in Tunisia and of the volatile organic compounds (VOCs) emitted by the powder of each organ were identified. The EOs are extracted from fresh material by hydrodistillation, whereas the VOCs are obtained by head space solid-phase microextraction (HS-SPME) from the powdered dry tissues. Fifty-eight VOCs are identified, while, 105 components are detected for the EOs. The main EOs compounds are α-neoclovene, ß-caryophyllene and limonene in roots (22.56, 12.52, and 8.59 %, respectively), viridiflorol in young stems, flowers and young leaves (34.90, 31.60, and 24.60 %, respectively), α-cadinol in young stems and leaves, and flowers (13.80, 10.40, and 9.10 %, respectively), (E)-nerolidol in flowers (13.30 %), and germacrene D in old stems (9.06 %). The major detected VOCs are n-undecane, mainly in young and old leaves (71.40 and 40.90 %, respectively), n-nonane in young leaves and flowers (31.80 and 27.10 %, respectively), α-cubebene in old stems and flowers (22.60 and 15.50 %, respectively), and α-gurjunene and ß-gurjunene in roots (14.20 and 12.20 %, respectively). Principal Component Analysis (PCA) carried out on the 26 main volatile compounds (relative content exceeding 6 %) identified both by HS and in the EOs allowed their classification into two groups; compounds specific to roots and those specific to aerial parts. The later are subdivided in to two subgroups; old leaves and stems compounds subgroup, and young leaves and stems, and flowers one. We can notice that the two methods used to extract P. tobira volatile compounds and identify them are complementary. This study defines and differentiates, for the first time, the specific aroma profile of P. tobira from Tunisia. In addition to its ornamental value, all the organs of this species, could be valued as a source of volatile compounds useful in perfume, cosmetics and as food flavoring products.

Chemical Composition, Repellent, and Phytotoxic Potentials of the Fractionated Resin Essential Oil from Araucaria heterophylla Growing in Tunisia.

The resin essential oil (REO) of the Tunisian Araucaria heterophylla trunk bark was investigated for its chemical composition. Then, it was evaluated for its insecticidal and allelopathic activities. The REO was obtained by hydrodistillation for 9 h (yield of 4.2 % w/w). Moreover, fractional hydrodistillation was carried out at 3-hour intervals, resulting in 3 fractions (R1-R3), to facilitate chemical identification and localization of the aforementioned biological activities. GC/MS analysis of the obtained samples allowed the identification of 25 compounds, representing between 91.2 and 96.3 % of their total constituents, which consisted predominantly of sesquiterpene hydrocarbons, oxygenated sesquiterpenes and diterpene hydrocarbons. α-Copaene (10.8 %), γ-muurolene (5.8 %), α-copaen-11-ol (7.8 %), spathulenol (10.5 %), 15-copaenol (8.2 %), ylangenal (10.3 %), dehydrosaussurea lactone (7.7 %), and sandaracopimaradiene (11.4 %) were identified as major compounds. The second part aimed to assess the impact of the A. heterophylla EO and its three fractions for their insecticidal and repellent activity against Tribolium castaneum (Herbst), a stored grain pest, of which a strong repellent activity was noted. In addition, the studied samples showed high phytotoxic effects against Lactuca sativa. The third fraction (R3) performed a total inhibitory potential on seed germination and seedling growth of the target plant. Furthermore, alongside this discovery, an estimation was conducted through molecular docking analysis. Wherein the main compounds of the studied samples were docked into the active pocket of protoporphyrinogen IX oxidase (PDB: 1SEZ), a key enzyme in chlorophyll biosynthesis. Thus, it is recommended to use the REO of A. heterophylla as a natural herbicide.

Chemical Composition and Insecticidal Activity against Tribolium Castaneum of Thapsia garganica L. Seed Essential Oil.

Due to the several side effects of synthetic pesticides, including environmental pollution, threats to human health, and the development of pest resistance to insecticides, the use of alternative healthy, available and efficient agents in pest management strategies is necessary. Recently, the use of essential oil obtained from aromatic plants has shown significant potential for insect pest management. For this reason, the essential oil isolated from seeds of Thapsia garganica L. was investigated for the first time for its chemical profile, and its toxicity and repellency effects against Tribolium castaneum adults. Qualitative and quantitative analyses of the chemical composition by gas chromatography coupled to mass spectrometry (GC/MS) revealed the presence of 18 organic volatiles representing 96.8 % of the total constituents. The main compounds were 1,4-dimethylazulene (51.3 %) followed by methyl palmitate (8.2 %), methyl linoleate (6.2 %) and costol (5.1 %). Concerning the repellent effect, results revealed that SEO (Seed Essential Oil) was very repellent towards T. castaneum adults, with 100 % repellency after 2 h of exposure. Furthermore, the essential oil exhibited remarkable contact toxicity against T. castaneum (93.3 % of mortality) at the concentration of 10 % (v/v). The median lethal dose (LD50 ) of the topical application of the seed essential oil was 4.4 %. These encouraging outcomes suggested that the essential oil from T. garganica seeds could be considered a potent natural alternative to residual persistent and toxic insecticides.

Resilience of Stevia rebaudiana (Bertoni) Bertoni in the Underwater Biospheres of Nemo's Garden®: Adaptation to New Cultivation Systems.

The Nemo's Garden® project is an alternative production system for areas with scarce cultivable land but significant presence of water; thus, it is an interesting intervention to address the climate crisis. This work aimed to evaluate the micromorphological, biochemical, and phytochemical characteristics of Stevia rebaudiana (Bertoni) Bertoni grown underwater compared to the terrestrial specimens. The micromorphological analyses, performed on the leaves using light microscopy, fluorescence microscopy, and scanning electron microscopy, evidenced a general uniformity of the trichome morphotype and distribution pattern. The histochemical investigation indicated the simultaneous presence of terpenes and polyphenols in the trichome secreted material from the underwater samples and a prevailing polyphenolic content in the terrestrial specimens; this was also confirmed by biochemical analyses (26.6 mg GAE/g DW). The characterization of non-volatile components, performed using HPLC-MS, showed similar chemical profiles in all the samples, which were characterized by phenolic compounds and steviol glycosides. The volatile compounds, evaluated using HS-SPME coupled with GC-MS, showed sesquiterpene hydrocarbons as the main class in all the analyzed samples (80.1-93.9%). However, the control plants were characterized by a higher content of monoterpene hydrocarbons (12.1%). The underwater biosphere environment did not alter S. rebaudiana micro-morphological characters, although slight qualitative changes were evidenced for the compounds produced as a response to the growth conditions.

Chemical Composition and Cytotoxic Activity of Eucalyptus torquata Luehm. and Eucalyptus salmonophloia F.†Muell. Trunk Bark Essential Oils against Human SW620 and MDA-MB-231 Cancer Cell Lines.

In recent years, there has been a growing interest in the screening of natural active ingredients from Eucalyptus essential oils because of their evident importance in practical utility and their undeniable therapeutic properties. Based on this, the aim of the present study was to investigate the chemical profile of the essential oils of the trunk bark of Eucalyptus torquata Luehm. (ETEO), and E. salmonophloia F. Muell. (ESEO), growing in Tunisia. The in vitro cytotoxic properties of the extracted EOs were also evaluated against two human cancer cell lines: breast carcinoma cell lines MDA-MB-231 and colorectal cancer cell lines SW620. The analysis by gas chromatography coupled with mass spectrometry (GC/MS) led to the identification of 32 compounds from the ETEO, with the dominant constituents being the monoterpenes trans-myrtanol (73.4 %) and myrtenol (4.7 %), and the apocarotene (E)-ß-ionone (3.9 %). In the case of ESEO, 29 compounds were identified with trans-myrtanol (25.0 %), decanoic acid (22.1 %), nonanoic acid (9.8 %), γ-elemene (6.5 %), γ-maaliene (5.5 %), and α-terpineol (5.3 %) as the main components. The cytotoxicity of EOs against the two chosen cell lines was tested using Crystal Violet Staining (CVS) assay and 5-fluorouracil as a reference drug. The two EOs exhibited a significant dose-dependent inhibition against the viability of the used cell lines. Their inhibitory effects were particularly observed towards SW620 colon carcinoma cells with IC50 values of 26.71±1.22 and 22.21±0.85 µg/mL, respectively, indicating that both oils were more cytotoxic for SW620 cells compared to MDA-MB-231 one.

Influence of the Use of an Ionic Liquid as Pre-Hydrodistillation Maceration Medium on the Composition and Yield of Cannabis sativa L. Essential Oil.

Cannabis sativa L. is a multi-purpose crop, whose resilience, adaptability and soil-enriching properties make it a low-impact production. In the last years, the cultivation of the "industrial" hemp varieties (THC < 0.2%) has been promoted by many Countries, opening a whole new market of hemp-derived products, such as its essential oil (EO). Its distillation might represent an effective method to exploit a residue of the hemp fiber production (flowers), complying with the guidelines of the circular economy. In the present work, different concentrations of an ionic liquid (IL; 1,3-dimethyl-1H-imidazol-3-ium dimethylphosphate) have been studied as a pre-hydrodistillation maceration medium. The EO yields have been evaluated, and their compositions have been analyzed by GC-EIMS. The use of 100% and 90% IL concentrations gave a hydrodistillation yield increment of 250% and 200%, respectively. The 200% yield increase was maintained when the 100% IL was recycled after the hydrodistillation. The lower IL concentrations incremented the cannabinoid and oxygenated sesquiterpene contents, while the opposite was true for sesquiterpene hydrocarbons. The proposed IL-enhanced hydrodistillation medium applied to hemp, studied for the first time in the present work, might be used to both (i) noteworthy increment the hydrodistillation yield and (ii) modulate the obtained EO composition based on the desired final product.

Essential Oil Analysis and Antimicrobial Evaluation of Three Aromatic Plant Species Growing in Saudi Arabia.

Arabian flora is a rich source of bioactive compounds. In this study, we investigated three aromatic plant species with the aim of finding valuable sources of antimicrobial agents against common pathogenic microorganisms. We focused especially on microorganisms, which cause outbreaks of infectious disease during mass gatherings and pilgrimages season in Saudi Arabia. The essential oils of three aromatic plant species were hydrodistilled from flowering aerial parts of Lavandula pubescens Decne. and Pulicaria incisa subsp. candolleana E.Gamal-Eldin, and from leaves, stems, ripe and unripe fruits of Juniperus procera Hochst. Ex Endl. They were subsequently analyzed by gas chromatography-mass spectrometry (GC-MS). The main constituents of L. pubescens were found to be carvacrol (55.7%), methyl carvacrol (13.4%), and ß-bisabolene (9.1%). P. incisa subsp. Candolleana essential oil was rich in linalool (33.0%), chrysanthenone (10.3%), eugenol (8.9%), and cis-chrysanthenol (8.0%); the major components of J. procera essential oil were α-pinene (31.3-62.5%) and δ-3-carene (7.3-30.3%). These essential oils were tested against thirteen American Type Culture Collection (ATCC) strains of Gram-positive and Gram-negative bacteria using the agar diffusion assay. The only effective essential oil was that of L. pubescens and the most sensitive strains were Acinetobacter baumannii, Salmonella typhimurium, Shigella sonnei, Enterococcus faecalis and Staphylococcus epidermidis. Carvacrol, the major constituent of L. pubescens, was tested on these strains and was compared with vancomycin, amikacin, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays of L. pubescens essential oil and carvacrol revealed that Gram-negative strains were more susceptible than the Gram-positive ones.

Essential Oil of Cannabis sativa L: Comparison of Yield and Chemical Composition of 11 Hemp Genotypes.

Cannabis sativa L. is an annual species cultivated since antiquity for different purposes. While, in the past, hemp inflorescences were considered crop residues, at present, they are regarded as valuable raw materials with different applications, among which extraction of the essential oil (EO) has gained increasing interest in many fields. The aim of the present study is the evaluation of the yield and the chemical composition of the EO obtained by hydrodistillation from eleven hemp genotypes, cultivated in the same location for two consecutive growing seasons. The composition of the EOs was analyzed by GC-MS, and then subjected to multivariate statistical analysis. Sesquiterpenes represented the main class of compounds in all the EOs, both in their hydrocarbon and oxygenated forms, with relative abundances ranging from 47.1 to 78.5%; the only exception was the Felina 32 sample collected in 2019, in which cannabinoids predominated. Cannabinoids were the second most abundant class of compounds, of which cannabidiol was the main one, with relative abundances between 11.8 and 51.5%. The statistical distribution of the samples, performed on the complete chemical composition of the EOs, evidenced a partition based on the year of cultivation, rather than on the genotype, with the exception of Uso-31. Regarding the extraction yield, a significant variation was evidenced among both the genotypes and the years of cultivation.

Chemical Composition and Cytotoxic Activity of the Fractionated Trunk Bark Essential Oil from Tetraclinis articulata (Vahl) Mast. Growing in Tunisia.

The aim of the present research was to determine the chemical composition and the cytotoxic effects of Tetraclinis articulata trunk bark essential oil (HEE) obtained by steam distillation and five fractions obtained by normal phase silica chromatographic separation. Chemical analysis allowed the identification of 54 known compounds. Relatively high amounts of oxygenated sesquiterpenes (44.4-70.2%) were detected, mainly consisting of caryophyllene oxide (13.1-26.6%), carotol (9.2-21.2%),14-hydroxy-9-epi-(E)-caryophyllene (3.2-15.5%) and humulene epoxide II (2.6-7.2%). The cytotoxic activity against human mammary carcinoma cell lines (MDA-MB-231) and colorectal carcinoma cell lines (SW620) of the essential oil and its fractions were assessed. All the samples displayed moderate to weak activity compared to 5-fluorouracil. The colorectal carcinoma cell line was relatively more sensitive to the essential oil and its fractions compared to the breast cancer cell line, showing IC50 values from 25.7 to 96.5 µg/mL. In addition, the essential oil and its fraction E.2 revealed a cytotoxic activity against colorectal carcinoma cell line, with IC50 values lower than 30 µg/mL. This is the first report on the chemical composition and cytotoxic activity of the trunk bark essential oil of T. articulata.

Lavandula dentata from Italy: Analysis of Trichomes and Volatiles.

This study presented a micromorphological and phytochemical survey on Lavandula dentata L. cultivated at the Ghirardi Botanic Garden (Toscolano Maderno, BS, Italy). The morphological investigation revealed the presence of peltate, short- and medium-stalked capitate trichomes. The histochemical survey showed terpene production by peltates and medium-stalked capitates, hydrophilic secretions by short-stalked capitates. The phytochemical survey was developed on leaf and flower volatile organic compounds (VOCs) and on the essential oil (EO) from the flowering aerial parts. The VOC profiles represented an element of novelty and were dominated by oxygenated monoterpenes, among which 1,8-cineole and ß-pinene were the most abundant (77.40 %, 7.11 % leaves; 81.08 %, 10.46 % flowers). The EO of L. dentata was dominated by oxygenated monoterpenes with a high percentage of 1,8-cineole (69.08 %), followed by ß-pinene, trans-pinocarveol and myrtenal. Evaluations about the ecological role, the potential biological activity and the sensory attributes were proposed, based on literature contributions.

Chemical Composition and Insecticidal Activity of Crithmum Maritimum L. Essential Oil against Stored-Product Beetle Tribolium Castaneum.

Several plant essential oils have been used against diverse insect pests since, unlike conventional pesticides, they pose almost no risk to humans and the environment. For this reason, the essential oil (EO) isolated from the fresh leaves of Crithmum maritimum L. and its fractions (F1 -F5 ) obtained by chromatographic simplification were investigated for their chemical profile, as well as for their toxicity and repellency effects against Tribolium castaneum (Herbst) adults. The analysis by GC/MS allowed the identification of 92.8-99.1 % of the compositions of the total oil (EO) and of its fractions (F1 -F5 ). The EO and its fractions F3 -F5 were characterized by the presence of a high amount of phenylpropanoids (94.4, 94.8, 93.6, and 88.7 %, respectively): in all the samples, dill apiole was the most abundant component (EO: 94.1 %, F3 : 94.6 %, F4 : 93.4 %, and F5 : 83.3 %). In addition, the repellency assay results showed that the volatile fraction F5 and the complete EO exhibited a higher repellency towards T. castaneum (97 % and 93 %, respectively) after 2 h of exposure at the dose of 0.04 µL/cm2 . The median lethal dose of the topical application of the EO was 9 %. Furthermore, the fraction F1 possessed interesting contact toxicity against T. castaneum (80 % of mortality) at the concentration of 10 %. These results suggested that the essential oil of C. maritimum leaves might be used as an alternative to synthetic insecticides in order to prevent insects from damaging the stored products.

Leek or Garlic? A Chemical Evaluation of Elephant Garlic Volatiles.

"Aglione della Valdichiana" is listed among the Traditional Agronomic and Edible Products of Italy, as it is a typical product of the Chiana Valley (Tuscany, Italy). It is also known as "elephant garlic", due to the dimension of its cloves, and, other than in the Italian Mediterranean area, its presence is also reported in North Africa and Southwest Asia. The current botanical classification identifies it as a leek variety (Allium ampeloprasum L.), although its appearance, except for its larger dimensions, resembles that of garlic. In the present study, the spontaneous volatile emission of whole and cut cloves of "Aglione della Valdichiana" (elephant garlic), garlic, and leek has been profiled by headspace solid phase micro-extraction. The results have been subjected to statistical analyses (analysis of variance, hierarchical cluster, and principal component analysis) to assess whether the chemical profile confirmed the botanical proximity of elephant garlic and leek, rather than garlic. The phytochemical volatiles evaluation indicated a higher proximity of elephant garlic to garlic, rather than leek, at least for the Chiana Valley specimen analyzed in this study.

Chemical Composition, Antioxidant, Anti-Tyrosinase, Anti-Cholinesterase and Cytotoxic Activities of Essential Oils of Six Algerian Plants.

In this study, the essential oils (EOs) of six Algerian plants (Artemisia campestris L., Artemisia herba-alba Asso, Juniperus phoenicea L., Juniperus oxycedrus L., Mentha pulegium L. and Lavandula officinalis Chaix) were obtained by hydrodistillation, and their compositions determined by GC-MS and GC-FID. The antioxidant activity of the EOS was evaluated via 2,2'-diphenyl-1-picrylhydrazyl (DPPH), ferric-reducing/antioxidant power (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assays. Moreover, their cytotoxic effect was evaluated-as well as their tyrosinase, acetyl- and butyryl-cholinesterase (AChE and BuChE) inhibitory activities. The chemical analyses detected 44, 45, 51, 53, 26 and 40 compounds in EOs of A. campestris, A. herba-alba, J. phoenicea, J. oxycedrus, M. pulegium and L. officinalis, respectively. A. campestris EO was mainly composed of ß-pinene (20.7%), while A. herba-alba EO contained davanone D (49.5%) as the main component. α-Pinene (41.8%) was detected as the major constituent in both J. phoenicea (41.8%) and J. oxycedrus (37.8%) EOs. M. pulegium EO was characterized by pulegone as the most abundant (76.9%) compound, while linalool (35.8%) was detected as a major constituent in L. officinalis EO. The antioxidant power evaluation revealed IC50 values ranging from 2.61 to 91.25 mg/mL for DPPH scavenging activity, while the FRAP values ranged from 0.97-8.17 µmol Trolox equivalents (TX)/g sample. In the ABTS assay, the values ranged from 7.01 to 2.40 µmol TX/g sample. In the presence of 1 mg/mL of the samples, tyrosinase inhibition rates ranged from 11.35% to 39.65%, AChE inhibition rates ranged from 40.57% to 73.60% and BuChE inhibition rates ranged from 6.47% to 72.03%. A significant cytotoxic effect was found for A. herba-alba EO. The obtained results support some of the traditional uses of these species in food preservation and for protection against several diseases.

Proapoptotic Activity of Achillea membranacea Essential Oil and Its Major Constituent 1,8-Cineole against A2780 Ovarian Cancer Cells.

Among the hundreds of reported Achillea species, A. membranacea (Labill.) DC. is one of the six that grow in Jordan. Many species of this genus are used in folk medicine to treat a variety of ailments and several biological and pharmacological activities have been ascribed to their essential oil (EO). For this study, the EO obtained from a specimen of A. membranacea grown in Jordan was analyzed by GC-MS. Ninety-six compounds were detected, of which oxygenated monoterpenes was the predominant class (47.9%), followed by non-terpene derivatives (27.9%), while sesquiterpenes represented 14.2% of the total composition. The most abundant compound in the EO was 1,8-cineole (21.7%). The cytotoxic activity of the EO was evaluated against three cancer cell lines (MCF7, A2780 and HT29), and one normal fibroblast cell line (MRC5) by MTT assay. Significant growth inhibition was observed in EO-exposed A2780 and HT29 cells (IC50 = 12.99 and 14.02 µg/mL, respectively), while MCF7 and MRC5 were less susceptible. The EO induced apoptosis and increased the preG1 events in A2780 cells. 1,8-Cineole, the major constituent of the EO, exhibited submicromolar cytotoxicity against A2780 cells, and was 42 times more selective against MRC5 cells. Its cytotoxicity against A2780 cells was comparable with that of doxorubicin, but 1,8-cineole was more selective for MRC5 normal cells. Interestingly, 1,8-cineole enhanced apoptosis in A2780, and caused a remarkable dose-dependent increase in preG1 events. Thus, 1,8-cineole has demonstrated promising cytotoxic and proapoptotic properties.

Activity of Thymus capitatus essential oil components against in vitro cultured Echinococcus multilocularis metacestodes and germinal layer cells.

The essential oil (EO) of Thymus capitatus, seven fractions (F1-F7) obtained from silica gel chromatography, and several pure EO components were evaluated with respect to in vitro activities against Echinococcus multilocularis metacestodes and germinal layer (GL) cells. Attempts to evaluate physical damage in metacestodes by phosphoglucose isomerase (PGI) assay failed because EO and F1-F7 interfered with the PGI-activity measurements. A metacestode viability assay based on Alamar Blue, as well as transmission electron microscopy, demonstrated that exposure to EO, F2 and F4 impaired metacestode viability. F2 and F4 exhibited higher toxicity against metacestodes than against mammalian cells, whereas EO was as toxic to mammalian cells as to the parasite. However, none of these fractions exhibited notable activity against isolated E. multilocularis GL cells. Analysis by gas chromatography-mass spectrometry showed that carvacrol was the major component of the EO (82.4%), as well as of the fractions F3 (94.4%), F4 (98.1%) and F5 (90.7%). Other major components of EO were ß-caryophyllene, limonene, thymol and eugenol. However, exposure of metacestodes to these components was ineffective. Thus, fractions F2 and F4 of T. capitatus EO contain potent anti-echinococcal compounds, but the activities of these two fractions are most likely based on synergistic effects between several major and minor constituents.

Isocostic Acid, a Promising Bioactive Agent from the Essential Oil of Inula viscosa (L.): Insights from Drug Likeness Properties, Molecular Docking and SAR Analysis.

The chemical composition of the essential oil (LEO) and its volatile fractions (V1 -V10 ) collected during the hydrodistillation process every 15 min from the fresh leaves of I. viscosa (L.), growing in Tunisia, were analyzed by GC-FID and GC/MS. Eighty-two compounds, representing 90.9-99.4 % of the total samples, were identified. The crude essential oil (LEO) and its fractions (V1 -V10 ) were characterized by the presence of a high amount of oxygenated sesquiterpenes (82.7-95.8 %). Isocostic acid (1) was found to be the most abundant component (37.4-83.9 %) and was isolated from the same essential oil over silica gel column chromatography and identified by spectroscopic methods (1 H, 13 C, DEPT 135 NMR and EI-MS) and by comparison with literature data. Furthermore, the fresh leaves essential oil (LEO), its volatile fractions (V1 -V10 ) as well as compound 1 were screened for their antibacterial, antityrosinase, anticholinesterase and anti-5-lipoxygenase activities. It was found that the isolated compound 1 exhibited an interesting antibacterial activity against Staphylococcus aureus ATCC 25923 (MIC=32 µg/mL) and Enterococcus faecalis ATCC 29212 (MIC=32 µg/mL) and the highest antityrosinase activity (IC50 =13.82±0.87 µg/mL). Compound 1 was also found to be able to strongly inhibit 5-lipoxygenase with an IC50 value of 59.21±0.85 µg/mL. The bioactivity and drug likeness scores of compound 1 were calculated using Molinspiration software and interpreted, and the structure-activity relationship (SAR) was discussed with the help of molecular docking analysis.

Profiles of the Essential Oils and Headspace Analysis of Volatiles from Mandragora autumnalis Growing Wild in Tunisia.

Mandragora autumnalis Bertol. (Solanaceae family), synonym of M. officinalis Mill., occurs in North Africa and grows natively in Northern and Central Tunisia, in humid to sub-arid climates. The ripe fruits of mandrake are odiferous with a particular, indescribable, specific odor, shared, to a lesser extent, by the leaves and roots. We carried out an investigation of the essential oils (EOs) and of the aromatic volatiles emitted by fresh leaves, roots and ripe fruits of M. autumnalis growing wild in Central Tunisia. The EOs were obtained from freshly collected plant material by hydrodistillation, while the volatile emissions from the powdered M. autumnalis tissues were sampled by headspace solid phase microextraction (HS-SPME); both types of samples were analyzed by gas chromatography-mass spectrometry (GC/MS). Fifty-one compounds representing 96.2-98.6 % of the total oil compositions were identified in the three tissues and belonged to different chemical classes specifically in 16 esters, 12 alcohols, 12 hydrocarbons, 6 ketones, 3 aldehydes and 3 acids. The main constituents were pentadecanoic acid (34.2 %) and hexadecanol (26.3 %). A total of 78 volatile compounds emanating from M. autumnalis tissues, representing 94.1-96.4 % of the total volatile compositions, were identified: 22 esters, 11 alcohols, 9 aldehydes, 14 ketones, 7 nitrogen, 10 hydrocarbons, 2 lactones, 1 sulfur and 2 ethers. Ethyl hexanoate (12.3 %) and 1,3-butanediol (12.3 %) were at the highest relative percentages. This study characterizes and distinguishes M. autumnalis from Tunisia and attributes the compounds responsible for the intoxicating and particular odor of fruits. Chemosystematic of Mandragora autumnalis based on the identification of essential oils and headspace volatiles of each of its organ can be used to characterize this species according to its geographic distribution.

Valorization of the Green Waste from Two Varieties of Fennel and Carrot Cultivated in Tunisia by Identification of the Phytochemical Profile and Evaluation of the Antimicrobial Activities of Their Essentials Oils.

The purpose of this study was to identify the chemical composition and the antibacterial activity of the essential oils (EOs) extracted from the green tops of Daucus carota L. subsp. sativus (Hoffm.) Arcang. plants producing yellow roots (DcsYR) and those producing orange roots (DcsOR) and from two varieties of Foeniculum vulgare subsp. vulgare cultivated in Tunisia. Analyses revealed that the EOs from the two D. carota varieties were rich in constituents belonging to sesquiterpenes. Phenylpropanoids and non-terpene derivatives were the most abundant classes of compounds in the EOs from the two varieties of F. vulgare, of which compositions were predominated by (E)-anethole and p-acetonylanisole. All the tested EOs were significantly more effective against Gram-negative bacteria, and that obtained from var. azoricum was more active against the yeast Candida albicans than the reference drug. The EOs obtained from these by-products showed indeed interesting potential to be promoted as natural antimicrobials in food preservation systems, as well as the possibility to be used in flavor industries.

Essential Oil Composition and Biological Activity of "Pompia", a Sardinian Citrus Ecotype.

Pompia is a Sardinian citrus ecotype whose botanical classification is still being debated. In the present study, the composition of Pompia peel essential oil (EO) is reported for the first time, along with that of the leaf EO, as a phytochemical contribution to the classification of this ecotype. The peel EO was tested for its antioxidant ability (with both the 2,2-diphenyl-1-picarylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). Moreover, its antimicrobial activities were tested for the first time on dermatophytes (Microsporum canis, Microsporum gypseum, and Trichophyton mentagrophytes), on potentially toxigenic fungi (Fusarium solani, Aspergillus flavus, and Aspergillus niger) as well on bacteria (Escherichia coli, Staphylococcus aureus, and Staphylococcus pseudointermedius). The dominant abundance of limonene in the peel EO seems to distinguish Pompia from the Citrus spp. to which it had previously been associated. It lacks γ-terpinene, relevant in Citrus medica EO. Its relative content of α- and ß-pinene is lower than 0.5%, in contrast to Citrus limon peel EO. Pompia peel and leaf EOs did not show significant amounts of linalool and linalyl acetate, which are typically found in Citrus aurantium. Pompia peel EO antioxidant activity was weak, possibly because of its lack of γ-terpinene. Moreover, it did not exert any antimicrobial effects either towards the tested bacteria strains, or to dermatophytes and environmental fungi.

Cold-Pressing Olive Oil in the Presence of Cryomacerated Leaves of Olea or Citrus: Nutraceutical and Sensorial Features.

The nutraceutical properties of extra-virgin olive oil (EVOO) can be further improved by the addition of olive leaves during olive pressing. However, while Citrus leaves are rich sources of bioactive substances, no data are available in the literature about the effect of Citrus leaf addition on the nutraceutical and sensorial profiles of olive oil. This study aimed at comparing the chemical and sensorial qualities of olive oils obtained from ripe olives pressed together with either Olea or Citrus spp. (lemon or orange) cryomacerated leaves. General composition parameters as well as major antioxidants and antioxidant activity were measured. A panel test evaluation, as well as headspace volatile characterization (headspace solid phase microextraction, HS-SPME), were also performed. All data were compared with an EVOO extracted from the same olive batch used as control. It was possible to obtain Leaf Olive Oils (LOOs) characterized by a higher (p < 0.05) content of antioxidants, compared to the control sample, and the highest oleuropein concentration was detected in the olive oil extracted in presence of olive leaf (+50% in comparison with the control). All the LOOs showed a higher smell complexity and the scent of ripe fruit was generally mitigated. Lemon and olive LOOs showed the best smell profile.