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Medicinal plants produce several natural bioactive molecules and compounds called secondary metabolites that have very important biological properties. The objective of this work is to determine the chemical composition of essential oils (EO) obtained from the leaves of three Tunisian species of Eucalyptus (E.oleosa, E.pimpiniana, E.polyanthemos) and to evaluate their biological activities. As a result, 45 different compounds were identified: 26 from E.pimpiniana, 15 from E.polyanthemos, and 39 from E.oleosa, which represent 99.4%, 99.4% and 98.6%, respectively, of the entire essential oil constituents. The analyses showed that 1,8-cineole (35.3%) and β-eudesmol (25.5%) were the main components in E.pimpiniana essential oil, whereas 1,8-cineole (71.6%) and globulol (13.2%) characterized E.polyanthemos leaf oil. Also, 1,8-cineole (13.4%), spathulenol (11.9%), and β-eudesmol (8.5%) were found to be the main constituents of E.oleosa EO. Other compounds, such as phellandral, p-cymen-7-ol (syn. cumin alcohol), carvacrol, myrtenal, cumin aldehyde and cryptone, are specific to the EOs of E.oleosa, making it distinct from the other Eucalyptus species studied. The essential oils showed low antioxidant capacity, but significant antifungal activity against five Fusarium spp. Indeed, E.oleosa essential oil exhibited the highest level of antifungal activity. Additionally, herbicidal activity has only been proved in a preliminary in vitro test against 3 weed species (Sinapisarvensis L., and Lepidiumsativum) of the same family. The greatest inhibition of seed germination was obtained with the E.oleosa essential oils even at low concentrations strongly suggesting that they could have application in agriculture, particularly as antagonists against Fusarium and other fungi and for weed control. [ABSTRACT FROM AUTHOR]

Olive oil, rich in bioactive compounds and antioxidants, is renowned for its health benefits. The lipoxygenase pathway contributes to the formation of antioxidant metabolites in virgin olive oils. This study examined the impact of location on volatile compounds, fatty acids, and antioxidants in Chétoui monovarietal olive oil from thirteen Tunisian regions. Analysis detected 37 volatile compounds, displaying significant compositional differences across regions. The predominant volatile compound, (E)-2-hexenal, exhibited noteworthy variations, reaching peak levels in Dogga II and Thibar at 24.9% and 23.1% respectively. Fatty acid composition revealed varying percentages of linoleic acid (C18:2) and linolenic acid (C18:3). Amdoun exhibited the highest C18:2 content at 17.5%. Similarly, C18:3 ranged from 0.7% in Slouguia to 0.8% in Teboursouk. Comparative analysis of oxidative stability and antioxidant activity indicated significant differences among regions. Testour II (52 h) and Medjez El-Bab II (44 h) demonstrated higher stability. Regarding antioxidant activity, Teboursouk displayed the highest value at 96.46% and 83.13% for DPPH and ABTS assays, while Thibar scored the lowest at 93.64% and 77.52% for DPPH and ABTS assays. The correlation coefficients reveal that oxidative stability has a negative correlation with DPPH activity (-0.4106) and ABTS activity (-0.491). In contrast, there is a strong positive correlation between oxidative stability and 1-Hexanol (0.584). Furthermore, the fatty acids C18:2 (-0.599) and C18:3 (-0.273) demonstrates negative correlations with oxidative stability. They provide novel insights into the relationship between the lipoxygenase pathway and olive oil's antioxidant properties, contributing to the production of high-quality olive oils with enhanced antioxidant attributes. [ABSTRACT FROM AUTHOR]

To our knowledge, this study represents the first investigation into the chemical composition of the essential oil of Euphorbia guyoniana Boiss. et Reut., a rare spontaneous species found in the sand dunes of Algeria. The essential oil was analyzed using gas chromatography-flame ionization detector and gas chromatography-electron impact mass spectrometry. The physicochemical properties of the oil, including relative density at 20°C, refractive index at 20°C, and optical rotation at 20°C, were determined according to ISO standards. The essential oil is primarily composed of nonterpene hydrocarbons, with significant amounts of apocarotenoids and oxygenated monoterpenes. The major compounds identified include n-pentadecane, n-heptadecane, n-tetradecane, hexahydrofarnesyl acetone, (E)-β-damascenone, (E)-β-ionone, and trans-piperitol acetate. [ABSTRACT FROM AUTHOR]

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is the single most important pest species affecting fresh fruit particularly citrus varieties. Over time, pest control approaches have been chronologically associated with procedures more and more friendly to the environment, starting with the use of insecticides, then sterile insecticides and finally plant essential oils as natural sources of pesticides. Essential oils (EO) extracted from leaves of Eucalyptus campaspe (Spencer Moore) and E. torquata Luehm were tested for their toxicity and repellency against C. capitata medflies. The EOs yields were 3.36% for E. campaspe and 1.83% for E. torquata. The main constituents in E. campaspe EO were 1,8-cineole (34.1%), β-eudesmol (10.4%) and globulol (9.7%), while the major components of E. torquata EO were globulol (42.7%), germacrene B (11.2%), β-eudesmol (6.7%) and viridiflorol (5.3%). In different trials E. campaspe EO showed higher toxic and repellent activities against C. capitata adults than E. torquata L EO. The EO of E. campaspe used as fumigant displayed a much more pronounced repellent and toxic effect on C. capitata than its formulation in ingestion or contact bioassays. While the EO of E. torquata had moderate insecticidal activities, E. campaspe EO has a higher inhibitory effect than that of E. torquata on acetylcholinesterase activity. The EOs of E. torquata and E. campaspe appeared to contain components that could serve as a basis for the synthesis of derivatives or analogs useful as pest control agents. [ABSTRACT FROM AUTHOR]

Olive leaves are rich in antioxidant compounds. During harvest, they reached about 10% of the total weight which can affect the olive oil quality. So, this work aimed to study the effect of adding different amounts of leaves (1, 2, 5, 10 and 20%) during the olive oil extraction of cv. Chemlali. Changes in physico-chemical indices, oil stability, fatty acid composition, antioxidant contents and volatile composition were evaluated. The obtained olive oils with the addition of less than 10% leaves were classified as Extra Virgin Olive Oil (EVOO). Polyphenols and bitterness index were the highest for treatments with addition of less than 10% leaves. Twenty-nine volatile compounds were identified. Total aldehydes and C6 compounds, responsible of the positive attributes, were the most abundant and were strongly affected by the addition of leaves. Olive oils with 2 and 5% added leaves were rich with aldehydes responsible of green and fruity flavor and in polyphenols. [ABSTRACT FROM AUTHOR]

Fruits from the same cultivar of Olea europaea L. cv. Chaaibi were picked at the same ripeness stage and processed quickly across varied environmental conditions in Tunisia. Solid-phase micro-extraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS) were used to determine the aroma profile of virgin olive oils. The volatile profiling was mostly constituted of compounds from the following chemical classes: esters, aldehydes, alcohols, and hydrocarbons. Significant variances in the percentages of volatile constituents in oils from diverse geographical origins were discovered, with the aldehyde (E)-2-hexenal being the predominant volatile in almost half of the oil samples. The findings imply that, in addition to genetics, growing area impacts aroma composition. Remarkably, the proportions of volatile compounds and fatty acid compositions in oils collected from different growing areas exhibited strong variability. These findings can be utilized to distinguish and describe Chaaibi olive oils from various areas. [ABSTRACT FROM AUTHOR]

The present work aims at evaluating the insecticidal activity of T. algeriensis and T. hyemalis (Lamiaceae) essential oils against different stages of Eceratoniae ceratoniae Zeller (Lepidoptera: Pyralidae) in controlled conditions. Essential oil vapours were isolated by hydrodistillation and analysed by gas chromatography–mass spectrometry technique (GC–MS). Camphor (37.29%), 1,8-cineole (11.12%), camphene (7.81%), myrcene (7.13%) and borneol (5.54%) were obtained as major compounds in the essential oil of T. algeriensis, while the main essential oil compounds of T. hyemalis were 1,8-cineole (34.17%), camphor (8.33%) and camphene (7.11%). Ovicidal activity of oils was studied by topical application, while the adulticidal and larvicidal activities were assessed by fumigation and ingestion. The results revealed that T. hyemalis oil was more effective as compared to T. algeriensis. The exposure to T. hyemalis vapour caused 0% of hatching rate at the concentration of 2.5 mg/ml, while at the same concentration, the hatching rate was 15% when eggs were exposed to T. algeriensis oil. The adulticidal activity of both oils decreased with the increase in concentration or exposure time. The corresponding LC50 values were found to be 0.11 and 0.19 mg/ml respectively for T. hyemalis and T. algeriensis. Young larvae L1 seemed to be more resistant to both essential oils in the antifeedant bioassay (LC50 = 2.75 mg/ml for T. hyemalis and 5.78 mg/ml for T. algeriensis). Overall, this work showed the efficacy of essential oils from plants of Mediterranean origin that could be used as an alternative to synthetic insecticides for the managing of E. ceratoniae. [ABSTRACT FROM AUTHOR]

The production of extra virgin olive oil (EVOO) flavored with diverse spices, herbs, fruits, and vegetables or natural aromas is believed to provide advantageous properties considering either the high nutritional value or biological activity in addition to the flavoring and industrial aspects. The biological activities including antioxidant and antimicrobial properties of Tunisian EVOO obtained from "Chemlali" variety and mixed with chili pepper were investigated. Molecular analyses, including the detection of twelve olive-infecting viruses and Pseudomonas savastanoi pv savastanoi, were performed to ensure that the samples were obtained from healthy olive trees and EVOO quality was not affected. Quality parameters like free acidity, peroxide number, oxidative stability, and specific absorption at K232 nm and K270 nm were also investigated and no significant variation was revealed. The content of minor compounds such as chlorophylls, carotenoids, and total phenols showed minor changes. However, the profiles of the volatile compounds showed remarkable differences, which appeared to be the main factor for the observed variability in consumer acceptance. The results showed for the first time high quantities of polyphenols and ortho-diphenols. Four colorimetric methods were used for the determination of the antioxidant activity, namely DPPH, ABTS, FRAP, and β-carotene test. Compared to the control, a higher level of antioxidant activity was observed for the flavored EVOO. Furthermore, significant results were obtained in the antimicrobial tests. The quality parameters of the mixture showed no alteration compared to the control. Finally, all the measurements and the chemical characterization gave a scientific basis for food technology innovation of new food products. [ABSTRACT FROM AUTHOR]

Cleome amblyocarpa Barr. and Murb is a medicinal plant widespread in North Africa and widely used in Tunisia to treat diabetes and colic. The non-volatile (polyphenols, flavonoids, tannins, and flavonols) and volatile compounds (GC-MS) of C. amblyocarpa leaves and stems have been studied. The antioxidant, antimicrobial, analgesic, and cytotoxic activities of hydroalcoholic extracts of C. amblyocarpa leaves and stems were also investigated. The major volatile components were β-caryophyllene (46.9%), eugenol (25.6%), ethyl 3-methylpentanoate (16.2%), 7-epi-silphiperfol-5-ene (11.0%), and α-copaene (7.0%). The antioxidant activity has been evaluated using various in vitro assays, such as DPPH free radical scavenging activity, iron-chelating capability, and ability to inhibit lipid peroxidation (TBARS). The antibacterial and antifungal effectiveness of leaves and stems parts of Cleome amblyocarpa were investigated by means of the disc diffusion and microdilution techniques. The in vitro cytotoxicity of the hydroalcoholic extract of C. amblyocarpa on A549 and H1299 lung adenocarcinoma cells was determined using the crystal violet assay. The acute toxicity of the extracts on Swiss albino mice at the doses of 3000, 1500, and 500 mg/kg body weight was evaluated. The analgesic effect of leaves and stems extract was also determined by means of the acetic acid induced writhing test. The results indicated that the leaves have higher phenols, and flavonoids contents and potential antioxidant, antimicrobial, and anticancer activities in comparison to stem. In addition, the aerial part of C. amblyocarpa did not cause signs of toxicity or death in animals at doses up to 3000 mg/kg and have a significant analgesic activity. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the polyphenolic and flavonoid contents in the leaves extracts of Ruscus hypophyllum. Antioxidant activity was estimated by α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assays. The anticoagulant activity of Ruscus extracts was evaluated in vitro, using the prothrombin time (PT) and a PTT-activated partial thromboplastin time tests. The antibacterial activity was tested against large number of important medically and resistant bacteria by the broth dilution method. In this study, ethyl acetate and chloroform extracts displayed the highest total phenols contents (74.76 mg EAG/g and 73.89 mg EAG/g, respectively) and flavonoid content 40 and 32.43 mg EC/g, respectively. The GC-MS analysis of ethyl acetate extract confirmed the presence of oxygenated sesquiterpenes and hydrocarbon diterpenes with percentages of 16.41% and 10.72%, respectively, but chloroform extract was rich with, oxygenated monoterpenes, and oxygenated diterpenes, with percentages of 6.19 and 3.27%, respectively. Among tested extracts, ethyl acetate exhibited the best antioxidant and anticoagulant activities. Furthermore, ethyl acetate and chloroform extracts showed important antibacterial activity against resistant bacteria methicillin-resistant Staphylococcus aureus (SARM), Acinetobacter imipenem-resistant (IMP/R), P. aeruginosa imipenem-resistant (IMP/R) and extended-spectrum beta-lactamase producing E. cloacae (BLSE) with minimal inhibitory concentration (MIC) values varying between 0.125 and 0.5 mg/mL. [ABSTRACT FROM AUTHOR]

As one of the last places where coffee grows spontaneously, the Harenna forest (Ethiopia) is the origin of the coffee analysed in this study. The analysis of the volatile emission of each processing phase evaluates the chemical fingerprint of the reactions taking place at each stage, leading to the final aroma. The green beans mainly emit non-terpene esters and alkanes. Once the roasting begins, monoterpenes are the main class until 160 °C: at this point, 2,6-dimethylpyrazine prevails in the headspaces, as main product of the Maillard reactions. This compound, with its sweet and nut-like aroma, is also detected in the brewed coffee. The shed silverskins are rich in methyl chavicol and retain the monoterpenes on the beans: as these compounds are important aroma contributors, the removal of the silverskins prior to roasting seems non-advisable. The grinding of the samples breaks the matrices and leads to drastic changes in the volatile emissions. [ABSTRACT FROM AUTHOR]

Main conclusion: Volatile emissions were detected for the first time in male flowers of the early-branching angiosperm Amborella trichopoda, suggesting a defensive and attractive double role of these compounds. Flower volatile emissions were detected for the first time in male flowers of the early-branching angiosperm Amborella trichopoda. A mixture of seven volatile compounds is found in flower buds, with limonene resulting as the most abundant compound (67%). Further five volatiles are found in freshly opened flowers, with limonene contributing to 31.7%, followed by decanal (15.5%) and by ethyl octanoate (10.3%). While monoterpene hydrocarbons dominate in flower buds (73.6%), their emission in freshly opened flowers is reduced to 41.1%, while non-terpene derivatives are the most abundant (47.1%) chemical class. These compounds, emitted in low amounts, are possibly linked to pollen, which is considered the only reward offered for insect-pollination in this species. [ABSTRACT FROM AUTHOR]

Main conclusion: Salinity alters VOC profile in emitter sweet basil plants. Airborne signals by emitter plants promote earlier flowering of receivers and increase their reproductive success under salinity. Airborne signals can prime neighboring plants against pathogen and/or herbivore attacks, whilst little is known about the possibility that volatile organic compounds (VOCs) emitted by stressed plants alert neighboring plants against abiotic stressors. Salt stress (50 mM NaCl) was imposed on Ocimum basilicum L. plants (emitters, namely NaCl), and a putative alerting-priming interaction was tested on neighboring basil plants (receivers, namely NaCl-S). Compared with the receivers, the NaCl plants exhibited reduced biomass, lower photosynthesis, and changes in the VOC profile, which are common early responses of plants to salinity. In contrast, NaCl-S plants had physiological parameters similar to those of nonsalted plants (C), but exhibited a different VOC fingerprint, which overlapped, for most compounds, with that of emitters. NaCl-S plants exposed later to NaCl treatment (namely NaCl-S + NaCl) exhibited changes in the VOC profile, earlier plant senescence, earlier flowering, and higher seed yield than C + NaCl plants. This experiment offers the evidence that (1) NaCl-triggered VOCs promote metabolic changes in NaCl-S plants, which, finally, increase reproductive success and (2) the differences in VOC profiles observed between emitters and receivers subjected to salinity raise the question whether the receivers are able to “propagate” the warning signal triggered by VOCs in neighboring companions. [ABSTRACT FROM AUTHOR]

In this study, the potential of date seed extracts to induce growth inhibition and apoptosis in HepG2 and HeLa cells was investigated. Analysis of the phytochemical compound content of the two Tunisian minor date seed extracts named Arechti and Korkobbi was determined. Moreover, their antioxidant properties are assessed through different assays including DPPH, ABTS, FRAP, TBARS, and phosphomolybdenum methods. Whereas, the cytotoxic effect was evaluated and apoptosis induction was confirmed by western blot technique (caspase-9, caspase-3, and PARP-1). The results proved the richness in phytochemical compounds of these by-products which explains the high in vitro antioxidant activity and the antiproliferative effects of both seed extracts. Additionally, the decrease in total PARP-1, procaspase-3 levels, and the increase of cleaved caspase-9 revealed the apoptotic effect of date seed extracts. These results collectively illustrate the potential of date seed extracts to induce growth inhibition and apoptosis in HepG2 and HeLa cells thanks to its phytochemical richness. [ABSTRACT FROM AUTHOR]

This study aimed to identify the physicochemical and the chemical properties of Ailanthus altissima (Miller) Swingle seed oil and to evaluate its in vitro antioxidant and antibacterial activities and in vivo analgesic and anti-inflammatory activities. The fatty acids' composition was determined using GC-FID. The oil was screened for antioxidant activity by DPPH test. The analgesic and anti-inflammatory activities were determined using the acetic acid writhing test in mice and the carrageenan-induced paw edema assay in rats, respectively. Volatile compounds were characterized by HS-SPME-GC-MS. A. altissima produces seeds which yielded 17.32% of oil. The seed oil was characterized by a saponification number of 192.6 mg KOH∙g of oil, a peroxide value of 11.4 meq O2∙kg of oil, a K232 of 4.04, a K270 of 1.24, and a phosphorus content of 126.2 ppm. The main fatty acids identified were palmitic (3.06%), stearic (1.56%), oleic (38.35%), and linoleic acids ones (55.76%). The main aroma compounds sampled in the headspace were carbonyl derivatives. The oil presents an important antioxidant activity (IC50 = 24.57 μg/mL) and a modest antimicrobial activity. The seed oil at 1 g/kg showed high analgesic (91.31%) and anti-inflammatory effects (85.17%). The presence of high levels of unsaturated fatty acids and the noteworthy antioxidant capacity of the seed oil can hypothesize its use as an analgesic and anti-inflammatory agent. [ABSTRACT FROM AUTHOR]

Diabetes is a serious condition that is linked to the development of oxidative stress causing among many other effects, kidney failure and pancreatic disorders. However, traditional plant-based remedies can be considered an alternative to diabetes healing. In this context, this study was oriented towards evaluating the protective effect of the flowers of Opuntia microdasys Lehm. collected in Tunisia at a biochemical and histological level on kidneys and pancreas of a type 2 diabetic rats. Renal and pancreatic toxicities were induced in diabetic male Wistar rats by fructose alloxan. Diabetic rats were treated with an extract obtained from flowers collected at post-flowering stage (OFP) (100 and 200 mg kg−1 bw) and metformin (100 mg kg−1 bw) for 28 days. Oral administration of OFP at 200 mg kg−1 bw showed significant reduction of the uric acid, urea, creatinine, amylase, lipase, and glycated hemoglobin (HbAlc). The levels of SOD, CAT, and GPx were increased, while protein carbonyls and lipid peroxidation TBARS levels were reduced in the kidney and pancreas. The altered kidney and pancreas histology were restored in rats treated with OFP. Thus, the present study demonstrated that OFP has antihyperglycemic activity in fructose-alloxan-induced diabetic rats. [ABSTRACT FROM AUTHOR]

The chemical composition, antimicrobial and antioxidant properties of Carum copticum essential oil and its methanolic extract were investigated. Thirteen compounds were identified representing 99.3% of the total oil composition. Oxygenated monoterpenes (53.0%) dominated the C. copticum essential oil with high contents of thymol (51.7 ± 1.51%), p-cymene (26.9 ± 1.11%), γ-terpinene (16.7 ± 0.76%), and β-pinene (1.6 ± 0.15%). In the methanolic extract, the caffeic, gallic, chlorogenic, coumaric and ferulic acids, flavan-3-ols (catechin), flavone (hyperoside), and the flavonol quercetin were identified. Antimicrobial activity of essential oil and the organic extract was tested by disk diffusion and broth microdilution method. The essential oil was effective against the tested bacteria and yeast strains with the highest activity and the MICs and MBCs values were lower as compared to the methanolic extract. The essential oil showed anti-quorum sensing activity against Chromobacterium violaceum, and the IC50 value for violacein inhibition was 0.23 mg/ml. Both the essential oil and the methanolic extract also showed antioxidant activities. The results obtained highlight the potential use of C. copticum as a possible source of antimicrobial and antioxidant compounds to be used both as food flavor and as a broad spectrum antibiotic. [ABSTRACT FROM AUTHOR]

Purpose: The statistical evaluation of the chemical profile of seized hashish samples is a valuable tool to aid the estimation of the route through which the material has reached the dealers’ market.Methods: In this study, the complete volatile organic compound (VOC) emission profiles of 48 seized hashish samples have been analyzed by means of headspace solid-phase microextraction/gas chromatography-mass spectrometry and evaluated with chemometric tools; multivariate statistical analyses, both hierarchical cluster analysis and principal component analysis (PCA) methods have been performed on the results to assess the existence of possible patterns throughout the samples.Results: The total VOC emission profiles sharply distributed the samples in clusters based on their batches of origin; this trend was also clearly shown in the PCA plot, in which samples coming from the same seizure were grouped together. The Δ9-tetrahydrocannabinol (THC) content analysis did not show a relevant trend in terms of lot of origin of the samples.Conclusions: The evaluation of the VOCs released into the headspace traced a much more complete chemical profiling of the samples, as compared to the analysis of cannabinoids only, or the THC titration. The multivariate statistical analyses were very useful to estimate the origin of the seized material. [ABSTRACT FROM AUTHOR]

Pollinators provide a key service to both natural and agricultural ecosystems. Little is reported on the pollination chemoecology of Stevia rebaudiana (Asteraceae), a hermaphroditic species producing self-incompatible florets in small corymbs. We investigated the chemistry of volatiles potentially involved in its pollination system. The VOCs emitted by the corymbs of 27 F1 open-pollinated genotypes were collected by solid-phase micro-extraction and analyzed by gas chromatography-mass spectrometry (GC-MS), as well as morphometric data of the genotypes were recorded. Finally, we quantified the abundance of pollinators for each genotype. S. rebaudiana flowers were mainly visited by bees (Apidae and Halictidae), followed by hoverflies (Diptera: Syrphidae). GC-MS indicated that S. rebaudiana was characterized by a complex scent profile with large variability among F1 plants. Discriminant analysis showed that limonene, δ-elemene and bicyclogermacrene were the compounds explaining most of the scent bouquet difference between high attractive (>40 pollinators/plant) from low attractive pollinator power (<40 pollinators/plant). Limonene was the most representative VOC among plants that are more attractive to pollinators, while high emissions of δ-elemene and bicyclogermacrene were linked to plants that are less attractive to pollinators. S. rebaudiana morphometric data highlighted that, besides floral VOCs, corymb abundance and size, as well as plant height, may route pollinator visits. Overall, this study adds knowledge on floral phenology and pollinator ecological traits of S. rebaudiana, allowing a deeper understanding of its chemical ecology and pollination. [ABSTRACT FROM AUTHOR]

This paper reports the quality indices, the volatile components, phenolic compounds and the oxidative stability of monovarietal Tunisian cultivar (cv. Neb Jmel) extra-virgin olive oils cultivated in eight regions. Headspace solid-phase microextraction and HPLC-DAD were applied to analyze and quantify the volatile and phenolic compounds of the obtained extra-virgin olive oils. Twenty compounds have been identified and quantified, revealing the complex profile of Neb Jmel EVOO, composed, in order of abundance, by secoiridoids, phenolic alcohols, lignans, flavonoids and phenolic acids. A total of 40 volatile compounds belonging mainly to esters, aldehydes, ketones, aliphatic alcohols and hydrocarbons were determined. Significant differences in the proportions of volatile and phenolic constituents of oils from different geographical origins were observed. The major volatile component was the C aldehyde (hexanal and ( E)-2-hexenal) fraction, whose content was highly variable between the areas studied. The content of ( E)-2-hexenal ranged from 50.9 % in the Melloulech EVOO to approximately 39.8 % for El-Ala EVOO. [ABSTRACT FROM AUTHOR]

The essential oils obtained by the hydrodistillation from the fresh flowers, leaves, stems, and roots of Ferula communis L., growing in Tunisia were analyzed by GC and GC/MS. Thirty-two components were identified in the oil of flowers with camphor (18.3 %), α-pinene (15.3 %), and β-eudesmol (9.3 %) as the main constituents. Twenty-nine compounds were identified in the oil of stems with β-eudesmol (28.1 %), δ-eudesmol (11.1 %), and α-eudesmol (9.6 %) as the main compounds. Twenty compounds were characterized in the oil of roots with dillapiole (7.9 %), guaiol (7.3 %), and spathulenol (6.8 %). In the oil of leaves, α-eudesmol (25.2 %), β-eudesmol (20.7 %), δ-eudesmol (10.1 %), and caryophyllene oxide (7.2 %) were found as the main constituents. This study was undertaken to evaluate the antioxidant activity using DPPH ( 2, 2′- diphenyl- 1- picrylhydrazyl), ABTS ( 2, 2′- azinobis- 3- ethylbenzothiazoline- 6- sulfonic acid), reducing power, and catalase activity. We tested also the antibacterial, cytotoxic, and cholinesterase inhibition properties of the essential oil of different organs of F. communis. The essential oil of the stems showed the highest antioxidant activity (IC = 0.03 ± 0.001 mg mL), in DPPH assay and the important result of catalase (303.03 µmol HO degraded/min/protein) of F. communis. The antibacterial activity of the oil was determined by micro-well dilution assay. The best results (MIC = 0.156 ± 0.02 mg mL) were exhibited by the essential oil of the leaves of F. Communis against Pseudomonas aeruginosa. Besides, the strongest cytotoxic activity against Hela cells was shown with essential oils' leaves with an inhibition percentage of 79.05 % at the concentration of 500 µg mL. However, the best inhibition percentage of A 549 cells was detected for essential oils' leaves with an inhibition percentage of 54.56 % at 250 µg mL. Our finding showed that the essential oil of the flowers was the most active, with 64.623 % of inhibition against butyrylcholinesterase at 10 mg mL from the incubation time of 30 min. [ABSTRACT FROM AUTHOR]

Spent hops is a waste produced in large amount by the brewing industry. Rhyzopertha dominica and Sitophilus granarius are insects that cause important economic losses of stored foods. In this study, for the first time, spent hops has been evaluated as a source of essential oil (EO) and chemicals with repellent activity against R. dominica and S. granarius. Spent hops EO yield was 0.11 %. The terpenes myrcene, α-humulene, and β-caryophyllene were its main components (47 %). Spent hops EO RD values were 0.01 and 0.19 μL cm for R. dominica and S. granarius, respectively. Among the chemicals, myrcene was able to exert the highest repellency against R. dominica (RD = 0.27 µM cm), while limonene was the most effective compound against S. granarius (RD = 0.89 µM cm). These results indicate spent hops as an excellent source of EO and chemicals to be utilized as low-cost, eco-friendly insect pests repellents in the protection of stored food. [ABSTRACT FROM AUTHOR]

The behavioural response of the sweet potato whitefly, Bemisia tabaci biotype B, to the volatiles emitted by three different species of Callistemon ( C. laevis, C. pallidus and C. phoeniceus) was assayed in still-air, and Y-tube olfactometers. B. tabaci adults showed a preference for C. pallidus, while C. laevis and C. phoeniceus were less attractive to the insects when compared to a blank control or to C. pallidus. Volatile organic compounds emitted by the leaves of the three Callistemon species were analysed by solid phase microextraction coupled with GC-MS. 1,8-Cineole was detected in high percentages in C. phoeniceus and C. laevis headspaces, while linalool was abundant in the headspace of C. pallidus. Because of this difference, behavioural tests in the Y-tube olfactometer were carried out also with 1,8-cineole and linalool. Adults of B. tabaci were attracted by linalool, while they were repelled by 1,8-cineole compared with pure air or linalool. These results support the role of these volatiles in the host plant selection process by a herbivorous insect and lay the foundations for the development of sustainable control strategies based on the manipulation of insect pest behaviour. [ABSTRACT FROM AUTHOR]

Mosquitoes (Diptera: Culicidae) represent a threat for millions of people worldwide, since they act as vectors for important pathogens, including malaria, yellow fever, dengue and West Nile. Second to malaria as the world's most widespread parasitic disease, infection by trematodes is a devastating public health problem. In this study, we proposed two essential oils from plants cultivated in Mediterranean regions as effective chemicals against mosquitoes and freshwater snails vectors of Echinostoma trematodes. Chemical composition of essential oils from Achillea millefolium (Asteraceae) and Haplophyllum tuberculatum (Rutaceae) was investigated. Acute toxicity was evaluated against larvae of the West Nile vector Culex pipiens (Diptera: Culicidae) and the invasive freshwater snail Physella acuta (Mollusca: Physidae), an important intermediate host of many parasites, including Echinostoma revolutum (Echinostomidae). Acute toxicity of essential oils was assessed also on a non-target aquatic organism, the mayfly Cloeon dipterum (Ephemeroptera: Baetidae). Achillea millefolium and H. tuberculatum essentials oils were mainly composed by oxygenated monoterpenes (59.3 and 71.0 % of the whole oil, respectively). Chrysanthenone and borneol were the two major constituents of Achillea millefolium essential oil (24.1 and 14.2 %, respectively). Major compounds of H. tuberculatum essential oil were cis- p-menth-2-en-1-ol and trans- p-menth-2-en-1-ol (22.9 and 16.1 %, respectively). In acute toxicity assays, C. pipiens LC was 154.190 and 175.268 ppm for Achillea millefolium and H. tuberculatum, respectively. P. acuta LC was 112.911 and 73.695 ppm for Achillea millefolium and H. tuberculatum, respectively, while the same values were 198.116 and 280.265 ppm for C. dipterum. Relative median potency analysis showed that both tested essential oils were more toxic to P. acuta over C. dipterum. This research adds knowledge on plant-borne chemicals toxic against invertebrates of medical importance, allowing us to propose the tested oils as effective candidates to develop newer and safer vector control tools. [ABSTRACT FROM AUTHOR]

Flowering plants employ a wide variety of signals, including scent, to attract pollinators. The aim of this work was to examine whether flower volatiles in four closely related Crocus species are linked to species divergence and to the current knowledge on their pollination syndromes. Fragrances of freshly opened flowers in Crocus etruscus, C. ilvensis, C. neglectus, and C. vernus, all belonging to ser. Verni, were analyzed using GC/MS. Results coincide with present knowledge about systematic relationships among taxa. The four species fall into two main fragrance types, based on similarities of their volatile compounds. In C. etruscus, C. ilvensis, and C. neglectus, oxygenated monoterpenes (lilac aldehyde B and A) are most abundant, while C. vernus has a fragrance rich in monoterpene hydrocarbons (α-pinene and limonene). Our results point towards outcrossing mating strategies for C. etruscus, C. ilvensis, and C. neglectus, whose volatile compounds are known as pollinator attractants. This is in line with their flower architecture, showing a style of variable height, often overtopping stamens. On the other hand, a self-pollination strategy was repeatedly suggested in the literature for C. vernus, marked by flowers with the style deeply inserted in the stamens and also by a completely different flower bouquet. [ABSTRACT FROM AUTHOR]

In latest years, the importance of the Melaleuca alternifolia essential oil (EO) has been greatly empathised due to its anti-microbial and anti-inflammatory effects, as well as to its toxic properties towards many arthropods of great medical and veterinary importance. In this research, the EO extracted from aerial parts of M. alternifolia was evaluated for its toxicity against larvae of the most invasive mosquito worldwide, Aedes albopictus (Diptera: Culicidae), and towards adults of the water flea, Daphnia magna (Cladocera: Crustacea), a non-target aquatic organism that share the same ecological niche of A. albopictus. The chemical composition of M. alternifolia EO was investigated by GC-MS analysis. Tea tree EO was mainly composed by oxygenated monoterpenes, with 1,8-cineole as the major constituent. M. alternifolia EO exerted toxic activity against A. albopictus larvae, with a LC = 267.130 ppm. However, this EO had a remarkable acute toxicity also towards adults of the non-target arthropod D. magna, with a LC = 80.636 ppm. This research provide useful information for the development of newer and safer mosquito control tools, highlighting that the non-target effects against aquatic organisms that share the same ecological niche of A. albopictus larvae are crucial in the development of ecofriendly mosquito control strategies. Further research is needed to investigate the chronic and/or reproductive toxicity of M. alternifolia EO both towards target and non-target aquatic arthropods. [ABSTRACT FROM AUTHOR]

Solitary bees are major pollinators but their chemical communication system has been poorly studied. We investigated olfactory coding in Osmia cornuta from two perspectives, chemical and biochemical. We identified ( E)-geranyl acetone and 2-hexyl-1,3-dioxolane, specifically secreted by females and males, respectively. A transcriptome analysis of antennae revealed 48 ORs (olfactory receptors), six OBPs (odorant-binding proteins), five CSPs (chemosensory proteins), and a single SNMP (sensory neuron membrane protein). The numbers of ORs and OBPs are much lower than in the honeybee, in particular, C-minus OBPs are lacking in the antennae of O. cornuta. We have expressed all six OBPs of O. cornuta and studied their binding specificities. The best ligands are common terpene plant odorants and both volatiles produced by the bee and identified in this work. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The essential oils of many Apiaceae species have been already studied for their insecticidal and repellent properties against insect pests. In this research, the essential oil (EO) extracted from the fruits of Coriandrum sativum L. (Apiaceae) was evaluated for the first time for its larvicidal and repellent activities against the most invasive mosquito worldwide, Aedes albopictus Skuse (Diptera: Culicidae). The chemical composition of C. sativum EO was investigated by gas chromatography with electron impact mass spectrometry analysis. Coriander EO was mainly composed by monoterpene hydrocarbons and oxygenated monoterpenes, with linalool (83.6 %) as the major constituent. C. sativum EO exerted toxic activity against A. albopictus larvae: LC was 421 ppm, while LC was 531.7 ppm. Repellence trials highlighted that C. sativum EO was a good repellent against A. albopictus, also at lower dosages: RD was 0.0001565 μL/cm of skin, while RD was 0.002004 μL/cm. At the highest dosage (0.2 μL/cm of skin), the protection time achieved with C. sativum essential oil was higher than 60 min. This study adds knowledge about the chemical composition of C. sativum EO as well as to the larvicidal and repellent activity exerted by this EO against A. albopictus. On this basis, we believe that our findings could be useful for the development of new and safer products against the Asian tiger mosquito. [ABSTRACT FROM AUTHOR]

The chemical composition of the essential oils extracted from some Tunisian Hypericum species and their larvicidal activity against Culex pipiens larvae were evaluated. The chemical compositions of the essential oils from the aerial plant parts were analyzed using gas chromatography-mass spectrometry. One hundred and thirty-four compounds were identified, ranging between 85.1 and 95.4 % of the oil's composition. The components were monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, non-terpenic hydrocarbons, and others. The larvicidal activity of the essential oils was evaluated using a method recommended by WHO. Larvicidal tests revealed that essential oils from the Hypericum species have a significant larvicidal activity against C. pipiens, with LC ranging between 102.82 and 194.70 ppm. The most powerful essential oils against these larvae were Hypericum tomentosum and Hypericum humifusum samples, followed by the essential oil of Hypericum perforatum. [ABSTRACT FROM AUTHOR]

The chemical composition, antibacterial, and antifungal activities of the volatile fractions from fresh and dried leaves of three Olea europaea L. cultivars from Tunisia ( Neb jemel, Chemchali and Chemlali) have been studied. The volatile components were obtained via hydrodistillation and analyzed by GC-MS. The major constituents were ( E)-3-hexenol, 3-ethenylpyridine, ( E)-β-damascenone and phenylethyl alcohol, but their percentages varied according to the treatment of the leaves. Antioxidant activities were determined applying DPPH and ABTS radical-scavenging assays. In general, antioxidant activity of the volatile fraction obtained from fresh leaves was superior to that obtained from dried leaves. The antibacterial and antifungal activities of the volatile fractions from fresh and dried leaves were evaluated against four bacterial and four fungal strains. The volatile fractions showed significant antibacterial and antifungal effects. However, some differences were observed in the response for several microorganisms, because of the variability of the composition. This work gives further knowledge for extensive development of this medicinal plant. [ABSTRACT FROM AUTHOR]

Essential oils from three species of Chrysanthemum growing in Tunisia ( C. coronarium, C. fuscatum, and C. grandiflorum) were first analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) and then evaluated for toxicity and antifeeding action against Tribolium confusum. The essential oils obtained from leaves and flowers shared a similar qualitative composition, but the relative proportions of the constituents were quite different. The essential oil of C. grandiflorum was rich in sesquiterpenoids, while those of C. fuscatum and C. coronarium were rich in monoterpenoids. The main common constituents of all the essential oils were α-pinene, myrcene, α-humulene, β-caryophylene, spathulenol, and caryophyllene oxide. The most effective essential oil was obtained from the leaves of C. grandiflorum, that inhibited the relative growth rate (−0.03 mg/mg/d), efficiency of conversion of ingested food (−50.69%), relative consumption rate, caused an antifeeding effect (66.43%) and a high mortality (80%) of T. confusum larvae. Topical application C. grandiflorum essential oil caused a significant insect mortality that attends 27% after 7 days of treatment. While essential oil from C. coronarium flowers has contact and fumigant toxicity with a mortality of 9 and 13%, respectively. Results analysis highlights a relationship between essential oils composition and insecticidal activity against T. confusum. The study showed that each essential oil has specific chemical composition and act differently according to the nature of attributed test. The use of essential oils from different Chrysanthemum species with different methods helps poor farmers who store small amounts of grains to preserve it against pest infestation. [ABSTRACT FROM AUTHOR]

The volatiles emitted from young and old leaves of two poplar clones ( Populus deltoides x maximowiczii, Eridano, and P. x euramericana, I-214) were sampled after exposure to ozone (80 ppb, 5 h d, for 10 consecutive days) by solid phase microextraction and characterized by GC-MS. Only mature leaves of the ozone-sensitive Eridano clone developed necrosis in response to ozone exposure, and their membrane integrity was significantly affected by ozone (+86 and +18 % of levels of thiobarbituric acid reactive substances in mature and young leaves). The headspace of the poplar clones studied here contained mono- and sesquiterpenes, both hydrocarbons and oxygenated ones in Eridano, and only hydrocarbons in the clone I-214. Furthermore, some non-terpenes, such as C-C straight-chain aldehydes and C-C saturated and unsaturated aliphatic hydrocarbons, were detected. Other common non-terpene volatiles were oxygenated aliphatic compounds, mainly C-alcohols and their acetates. Ozone exposure induced a strong change in volatile profiles, depending on clones and leaf age. Regardless of leaf age, in clone I-214, quantities of oxygenated monoterpenes tended to increase after ozone exposure, however, 'O x leaf age' was not significant. In clone Eridano, increases were observed in emissions of hydrocarbons and oxygenated sesquiterpenes in response to ozone treatment. ( Z)-3-Hexen-1-ol and ( Z)-3-hexenol acetate were present in traces in the headspace of untreated Eridano mature leaves, but quantities slightly increased after ozone treatment. Quantities of non-terpene oxygenated compounds dropped in the headspace of young leaves of both clones (−24 and −44 % in Eridano and I-214) and also in mature ones of I-214 (−50 %) after ozone exposure. Similarly, quantities of non-terpene hydrocarbons in the emissions from mature leaves of both clones (−58 and −49 %, respectively) decreased, while these compounds increased in young leaves of Eridano (+83 %). We suggest that the resistance of the poplar clone I-214 to O is achieved by: i) monoterpenes constitutively present in young leaves and ii) increase of monoterpene content induced by O in mature leaves. [ABSTRACT FROM AUTHOR]

Lamiaceae have traditionally been used in developing countries for their insecticidal and repellent properties against several insect species. In our research, the essential oil (EO) extracted from fresh leaves of Hyptis suaveolens (Lamiaceae), and its main constituents were evaluated for larvicidal and repellent activity against the Asian tiger mosquito, Aedes albopictus Skuse (Diptera: Culicidae), currently the most invasive mosquito worldwide. H. suaveolens EO had insecticidal activity against A. albopictus larvae and mortality was dosage dependent. At the highest dosages of 450 and 400 ppm, there were no significant differences on larval mortality, as mortality ranged between 98.33% and 93.33%, respectively. At dosages ranging from 250 to 350 ppm, mortality rates were lower and not significantly different from each other. Terpinolene was found to be the most effective pure compound. Efficacy protection from H. suaveolens EO, at dosages ranging from 0.03748 to 0.7496 μg cm of skin, was evaluated during 150 min of observation. Results indicated that this EO had a significant repellent activity (RD = 0.00035 μg cm; RD = 0.00048 μg cm), with differences in repellency rates, as a function of both concentration and observation time. Protection time ranged from 16 to 135 min. These results clearly evidenced that the larvicidal and repellent activity of H. suaveolens EO could be used for the development of new and safer products against A. albopictus. [ABSTRACT FROM AUTHOR]

Essential oils from Hyptis suaveolens (L.) Poiteau (Lamiaceae) and Hyptis spicigera Lamarck (Lamiaceae) were first analysed by gas chromatography and by gas chromatography/electron impact mass spectroscopy and then evaluated for toxicity and repellent activity against Sitophilus granarius (L.) (Coleoptera: Dryophthoridae), one of the most serious worldwide stored grain pests. Fifty-six compounds have been identified in the essential oil of H. suaveolens: monoterpene hydrocarbons were the most represented volatiles (64.1%), followed by sesquiterpene hydrocarbons (24.0%), oxygenated monoterpenes (8.1%) and oxygenated sesquiterpenes (2.4%). Diterpenes and non-terpene derivatives were scarcely represented. Sixty compounds have been identified in the essential oil of H. spicigera: monoterpene hydrocarbons were the most represented class of volatiles (70.4%), followed by sesquiterpene hydrocarbons (22.6%). Results from topical applications on insects showed that both essential oils had an effective insecticidal activity. The complete kill of S. granarius was observed 24 h after treatment at a minimum effective dose of 0.4 and 0.6 μl per insect with H. suaveolens and H. spicigera oil, respectively. Results from repellency tests showed that the two essential oils had a repellent activity on S. granarius adults: at the lowest dose (2 × 10 μl oil per cm), H. spicigera essential oil exhibited a higher repellent effect in comparison to H. suaveolens. No significant differences were observed for the repellent effect between the two essential oils at the highest dose (2 × 10 μl oil per cm). [ABSTRACT FROM AUTHOR]

The article presents information on a study conducted on the essential oil of the plant species Carpolobia lutea. The plant Carpolobia lutea possesses anti-inflammatory, antimicrobial, and antimalarial properties, among others. In the study, leaves of Carpolobia lutea were taken for analysis, and the techniques used included gas chromatography (GC) and gas chromatography-electron ionization mass spectroscopy (GC-EI-MS).