Comparative chemical composition and antioxidant activity of olive leaves Olea europaea L. of Tunisian and Algerian varieties.

The main objective of this research was to understand the effect of different solvents (ethanol, ethyl acetate, and hexane) on the extraction of bioactive compounds in addition to the antioxidant activity of eight Tunisian and Algerian olive leaf (Olea europaea L) cultivars. The different extracts were evaluated for their content of total phenols, flavonoids, and condensed tannins. The antioxidant capacity was determined by ABTS (2,2-azinobis (3 ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1 picrylhydrazyl) methods. In addition, qualitative and quantitative analyses of phenolic compounds by HPLC were performed. In terms of phenolic content, ethanol was found to be the best solvent to extract phenolic compounds with antioxidant capacity. The ethanolic extract of Sigoise and Rougette varieties were the richest in total phenols 161.54 ± 0.99, and 160.53 ± 1.17 mg GAE/g DE respectively. The highest levels of flavonoids were detected in ethyl acetate extracts of Rougette (87.58 ± 6.99 mg QE/g DE) and Verdal varieties (86.77 ± 1.75 mg QE/g DE), whereas the hexanolic extracts of Gerboui, Sofiana, and Chemlali exhibited the higher amount of tannins (67.99 ± 5.41, 65.52 ± 1.94, 64.64 ± 1.51 mg CE/g DE, respectively). Furthermore, in the DPPH radical scavenging activity assay, the Sofiana extract exhibited the highest antioxidant activity (23.85 ± 0.58 mg/L). In another case, for the ABTS radical scavenging assay, the Verdal extract showed high antioxidant potential (30.22 ± 1.35 mg/L). HPLC analysis of ethanolic extracts of the different varieties allowed the identification of 19 organic compounds, with oleuropein (2604.01-7991.14 mg/100g DM) being the most abundant, followed by hydroxytyrosol (250.74-687.54 mg/100g DM) and verbascoside (216.12-672.64 mg/100g DM) being the major compounds in the olive leaves in all studied ethanolic extracts, with concentrations varying significantly according to the cultivars and geographical origin. Principal component analysis (PCA) performed on phenolic profiles and antioxidant activities revealed the influence of bioactive compounds on antioxidant activity, with high concentrations of phenols and flavonoids in olive leaf extracts having a strong antioxidant activity.

Ambipolar to Unipolar Conversion in C70/Ferrocene Nanosheet Field-Effect Transistors.

Organic cocrystals, which are assembled by noncovalent intermolecular interactions, have garnered intense interest due to their remarkable chemicophysical properties and practical applications. One notable feature, namely, the charge transfer (CT) interactions within the cocrystals, not only facilitates the formation of an ordered supramolecular network but also endows them with desirable semiconductor characteristics. Here, we present the intriguing ambipolar CT properties exhibited by nanosheets composed of single cocrystals of C70/ferrocene (C70/Fc). When heated to 150 °C, the initially ambipolar monoclinic C70/Fc nanosheet-based field-effect transistors (FETs) were transformed into n-type face-centered cubic (fcc) C70 nanosheet-based FETs owing to the elimination of Fc. This thermally induced alteration in the crystal structure was accompanied by an irreversible switching of the semiconducting behavior of the device; thus, the device transitions from ambipolar to unipolar. Importantly, the C70/Fc nanosheet-based FETs were also found to be much more thermally stable than the previously reported C60/Fc nanosheet-based FETs. Furthermore, we conducted visible/near-infrared diffuse reflectance and photoemission yield spectroscopies to investigate the crucial role played by Fc in modulating the CT characteristics. This study provides valuable insights into the overall functionality of these nanosheet structures.

Formulation of pasta enriched with protein-rich lupine (Lupinus mutabilis Sweet) and wheat bran using mixture design approach.

In recent years, as awareness of healthy diets has increased, consumers are becoming more aware of their food and are paying more attention to their diet. Nutritionists have recommended an increased consumption of dietary fiber in the daily diet to improve health. Within this context, this work aims to formulate "spaghetti" pasta enriched with lupin flour and wheat bran. For the formulation of the mixture of those flours, we used the NemrodW software to predict the optimal pasta formula. A physicochemical characterization, as well as the culinary quality of the pasta resulting from the different mixtures, was carried out to model each significant criterion and choose the optimal mixture that will be used in the pasta recipe. The evaluation of the physicochemical characteristics of the pasta showed that the addition of lupin flour and bran resulted in an improvement in the nutritional value of the enriched spaghetti. Following the results obtained, the software proposed an optimal mix and will be used for further study. This formula comprises 19.60% bran, 27.83% lupin flour, and 52.75% durum wheat semolina. The caloric value of the dough from the optimal mix was determined and compared to that of the standard dough. The results of our study indicated a significant improvement in the nutritional value of the enriched pasta compared to the standard pasta. The enriched pasta contained higher levels of protein, ash, lipids, polyphenols, and pigments and lower levels of sugars, which make it a more nutritious option for certain individuals, such as athletes or those following a protein or low-sugar diet. PRACTICAL APPLICATION: The proposed method of substituting wheat semolina with lupine flour and wheat bran in spaghetti formulation has demonstrated a potential for producing protein-rich and nutritionally enriched pasta. This approach can be useful for developing similar functional food products that cater to the dietary requirements of athletes or individuals following a protein or low-sugar diet.

Optimization of antioxidant and lycopene extraction from tomato pomace using Hansen solubility parameters and its application in chicken meat preservation.

Tomato pomace, composed of peels and seeds, is often discarded or used as animal feed. However, it contains valuable phytochemicals, including lycopene. Lycopene, a natural pigment, is an antioxidant known for reducing the risk of chronic diseases like cardiovascular ailments and cancer. In this study, we aimed to study the possibility of valorizing tomato pomace by quantifying phenolic compounds, evaluating the antioxidant activity of their extracts, as well as extracting and quantifying lycopene, and studying the effect of tomato peel extract on the oxidative stability of chicken patties during storage. The effectiveness of different solvent mixtures for the extraction of lycopene was evaluated using Hansen solubility parameters (HSPs). The obtained results showed that the best solvent mixture was hexane/acetone (50/50) with a Hansen theoretical distance of 7.2, indicating its favorable solvation power. It also achieved a notable extraction yield of 3.12% and the highest lycopene yield of 20.05 mg/100 g. This combination demonstrated the highest values in terms of total phenolic (24.06 mg equivalent gallic acid/100 g dry matter) and flavonoid content (30.55 mg equivalent catechin/100 g dry matter), indicating a significant presence of these compounds. However, its 1,1-diphenyl-2-picrylhydrazyl (13.51 µg/mL) and ABTS, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, (8.52 µg/mL) IC50 values were comparatively lower than the other mixes. The use of this fraction as a food additive and antioxidant showed significant competitiveness with the conventional preservative, 2,6-di-tert-butyl-4-methylphenol. Tomato extract can be considered a potential natural preservative in food preparations due to its high lycopene content. PRACTICAL APPLICATION: This research provides valuable insights into optimizing the extraction of antioxidants from tomato pomace, using HSPs. The findings have the potential to benefit the food industry by developing improved methods for preserving chicken meat through the application of these optimized antioxidant extracts. By enhancing the preservation process, this study may contribute to extending the shelf life and maintaining the quality of chicken meat, leading to reduced food waste and improved consumer satisfaction.

Encapsulation of Ammoides pusila Essential Oil into Mesoporous Silica Particles for the Enhancement of Their Activity against Fusarium avenaceum and Its Enniatins Production.

Essential oils (EOs) that have antifungal activity and mycotoxin reduction ability are candidates to develop bioactive alternatives and environmentally friendly treatment against Fusarium species in cereals. However, their practical use is facing limitations such as high volatility, UV sensitivity, and fast oxidation. Encapsulation techniques are supposed to provide protection to the EOs and control their release into the environment. Ammoides pusilla essential oil (AP-EO) proved to be an efficient inhibitor of Fusarium avenaceum growth and its enniatins (ENNs) production. In the present work, AP-EO was encapsulated, using the impregnation method, into mesoporous silica particles (MSPs) with narrow slit pores (average diameter = 3.1 nm) and coated with chitosan. In contact assays using an agar medium, the antifungal activity of AP-EO at 0.1 µL mL-1 improved by three times when encapsulated into MSPs without chitosan and the ENNs production was significantly inhibited both in coated and non-coated MSPs. Controls of MSPs also inhibited the ENNs production without affecting the mycelial growth. In fumigation experiments assessing the activity of the EO volatile compounds, encapsulation into MSPs improved significantly both the antifungal activity and ENNs inhibition. Moreover, coating with chitosan stopped the release of EO. Thus, encapsulation of an EO into MSPs improving its antifungal and antimycotoxin properties is a promising tool for the formulation of a natural fungicide that could be used in the agriculture or food industry to protect plant or food products from the contamination by toxigenic fungi such as Fusarium sp. and their potential mycotoxins.

Insecticidal effects of two Tunisian diatomaceous earth loaded with Thymus capitatus (L.) Hoffmans and Links as an ecofriendly approach for stored coleopteran pest control.

This study investigated composition and toxicity of Thyme EOs against two main stored grain insect pests. Carvacrol was distinguished as a major compound (78.34%). In laboratory tests, EOs applied by both direct contact and fumigant tests was more toxic to L. serricorne than T. castaneum. The EOs were also tested combined with two Tunisian Diatomaceous earths (DEs) against T. castaneum. The LC50 was 6.28 µL/L air for natural preparation EO/R1, 5.90 µL/L air for EO/R2 and 121.17 for crude EOs by fumigant test, respectively. While, contact test revealed that natural DEs; dust act as an insecticide with 'LC50' values of 3.22 and 0.29 µL/cm2f or R1 and R2, respectively. Moreover, a significant difference was noted between crude EO, EO/R1 and EO/R2. Overall, the enhancement of the Tunisian DEs' insecticidal activity by its mix with EOs may be a promising active substance as a stored grain protectant.

Functionalization of Pasteurized Milk Using Rosemary, Thyme, and Ammoides Aqueous Extracts for Better Microbial Quality and an Improved Antioxidant Activity.

This study aimed to evaluate the effects of thyme (Thymus vulgaris L.), rosemary (Rosmarinus officinalis L.), and ammoides (Ammoidespusilla L.) aqueous extracts supplementation on the quality of heat-treated (55, 65, and 75 °C) raw milk (sample lots: A, B, and C) and cold-stored pasteurized milk (lot D). The three herbs have shown rich polyphenol contents (32.65−104.23 mgGAE/g), relevant antioxidant capacity, and high caffeic and rosmarinic acids and catechin contents. A significant reduction in psychrotrophic and total viable bacteria counts (PC and TVC) was attained following milk extract supplementation in both experiments. Monitoring PC and TVC counts in sample lots (A, B, and C) has revealed a significant improvement in extracts' effectiveness in reducing the TVC count with the increment of temperature. The highest reductions of PC and TVC counts were achieved, respectively, in samples treated with thyme and rosemary in (lots: A, B, and C) and in samples treated with ammoides and thyme in (lot D). Thyme extract showed the highest milk serum DPPH scavenging activity (74.84% at 0.1 mg/mL) and induced a significant Listeria monocytogenes growth inhibition (>1 Log cycle). The sensory evaluation of supplemented milk has shown good consumer acceptability of ammoides-supplemented milk, quite similar to the control sample.

Preparation of chitosan/tannin and montmorillonite films as adsorbents for Methyl Orange dye removal.

A series of novel chitosan/tannin/montmorillonite (Cs/Tn/MMT) films were synthesised by loading different (from 0.2 to 0.5 wt%) and MMT (from 0.5 to 1.5 wt%) ratios, to be used as promising low-cost biosorbents for methyl orange (MO) removal from aqueous media. The prepared films were characterised using different techniques such as x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), water contact angle, optical properties, colourimetric measurement, porosity, swelling and thickness. The effects of various parameters, i.e. initial MO concentration, adsorbent dose, pH and temperature, were studied. The Cs/Tn0.2/MMT1 film showed a high removal efficiency of 95.62% and maximum adsorption capacity of 57.37 mg/g under the optimum adsorption conditions (initial methyl orange concentration 60 mg/L, pH 7 and 25 °C). The adsorption kinetic followed the pseudo second order kinetic model and the experimental data were a good fit for the Langmuir isotherm indicating a homogeneous and monolayer adsorption process. The thermodynamic parameters suggested physical adsorption and exothermic behaviour. Consequently, Cs/Tn/MMT films showed effective potential for the uptake of anionic dyes.

Characterization of Fusarium acuminatum: A Potential Enniatins Producer in Tunisian Wheat.

Fusarium Head Blight (FHB), caused by multiple species of Fusarium in small grain cereals, is a significant and long-standing problem anywhere in the world. Knowing regional Fusarium spp. present on non-symptomatic grains and their potential for mycotoxin production is of concern for identifying novel actions for FHB and mycotoxin management, such as treatments with essential oils. Analyzing the mycotoxin content of grains from non-symptomatic ears of different wheat varieties cultivated in Tunisia, we isolated Fusaria specimens identified as F. culmorum and F. acuminatum using analysis of the partial DNA sequence of the ß-tubulin gene and ITS region. Two isolates of the latter species, uncommon in cereal grains in this region until now, were shown to be effective producers of enniatins in vitro, with 1390 and 3089 µg g-1 mycelial biomass (dry) in 11-day-old cultures. The susceptibility of an isolate of F. acuminatum to the fungistatic and antimycotoxin effects of eight essential oils was measured. Essential oils from Ammoides pusilla and Thymus capitatus used at 0.1 µL mL-1 in an agar culture medium, affected the mycelial growth by 55% and 79%, respectively and reduced the accumulation of enniatins per unit of mycelial colony by 26% and 52%, respectively. Finally, F. acuminatum was shown to be a contaminant of wheat grains in Tunisia and it may contribute to the contamination in enniatins. Two essential oils of Tunisian plants could be used for developing a biofungicide limiting both its mycelial growth and its accumulation of mycotoxins in grains.

Exploration of the Mechanism of the Dimerization of Hydroxymethylsilanetriol Using Electronic Structure Methods.

Hydroxymethylsilanetriol undergoes condensation reactions to form new structures with an organic part in the formed bridges. As a first step to explore the formation of these bridges, we studied the corresponding mechanisms using simple models and theoretical methods. Three mechanisms were studied for the formation of dimers of hydroxymethylsilanetriol with bridges: Si-O-C-Si, Si-O-Si, and Si-C-O-C-Si. Energies are calculated using M06/6-311+G(d,p) single-point calculations on B3LYP-optimized geometries in solution and including B3LYP thermodynamic corrections. The first mechanism for the formation of the Si-O-C-Si bridge consists of one step. The second mechanism for the formation of the Si-O-Si bridge consists of two steps. The barrier for the last mechanism for the formation of the Si-C-O-C-Si bridge is too high and cannot occur at room temperature. The energy barriers are 31.8, 27.6, and 65.9 kcal mol-1 for the first, second, and third mechanisms, respectively. When adding one explicit water molecule, these energies are 25.9, 22.9, and 80.3 kcal mol-1, respectively. The first and second mechanisms can occur at room temperature, which is in agreement with the experimental results.

Chemical Composition and Biological Activities of Tunisian Ziziphus lotus Extracts: Evaluation of Drying Effect, Solvent Extraction, and Extracted Plant Parts.

The Tunisian Ziziphus lotus plant was investigated to determine its phytoconstituents and evaluate its biological activities. In particular, the GC/MS technique was used to describe the chemical composition of Z. lotus active extracts and fractions. Among the obtained extracts, the yields of the dried root methanolic extract (29.80%) and the fruit aqueous extract (48.00%) were the highest ones. The dried root methanolic extract exhibited the highest amount in the total phenolics (186.44 ± 0.26 mg GAE/g DW), total flavonoids (102.50 ± 3.53 mg QE/g DW), and tannins (60.714 ± 2.2 mg catechin/g DW). The root aqueous extracts revealed the highest antioxidant activity with an IC50 of 8.96 ± 0.38 mg/L and 16.46 ± 0.60 mg/L for the ABTS•+ and DPPH• assays, respectively. The total antioxidant capacity was accorded to the methanolic extract of the dried roots with a value of 304.07 ± 1.11 µg AAE/mg. The drying process was found to improve the qualitative and quantitative properties of the Z. lotus extracts. The evaluation of the cytotoxic activity against the SH-SY5Y cell line was carried out using MTT assay. The petroleum ether and dichloromethane extracts of the dried roots showed relevant cytotoxic activities. The thin layer chromatography and the GC-MS/GC-FID analysis led to the identification of the 13-epimanool as a potent cytotoxic compound.

Ammoides pusilla Essential Oil: A Potent Inhibitor of the Growth of Fusarium avenaceum and Its Enniatin Production.

Enniatins are mycotoxins produced by Fusarium species contaminating cereals and various agricultural commodities. The co-occurrence of these mycotoxins in large quantities with other mycotoxins such as trichothecenes and the possible synergies in toxicity could lead to serious food safety problems. Using the agar dilution method, Ammoides pusilla was selected among eight Tunisian plants for the antifungal potential of its essential oil (EO) on Fusarium avenaceum mycelial growth and its production of enniatins. Two EO batches were produced and analyzed by GC/MS-MS. Their activities were measured using both contact assays and fumigant tests (estimated IC50 were 0.1 µL·mL-1 and 7.6 µL·L-1, respectively). The A. pusilla EOs and their volatiles inhibited the germination of spores and the mycelial growth, showing a fungistatic but not fungicidal activity. The accumulation of enniatins was also significantly reduced (estimated IC50 were 0.05 µL·mL-1 for the contact assays and 4.2 µL·L-1 for the fumigation assays). The most active batch of EO was richer in thymol, the main volatile compound found. Thymol used as fumigant showed a potent fungistatic activity but not a significant antimycotoxigenic activity. Overall, our data demonstrated the bioactivity of A. pusilla EO and its high potential to control F. avenaceum and its enniatins production in agricultural commodities.

Clove Buds Essential Oil: The Impact of Grinding on the Chemical Composition and Its Biological Activities Involved in Consumer's Health Security.

This study is aimed at identifying the chemical composition of the essential oil extracted from the Syzygium aromaticum seeds, as well as investigating its biological activities, insecticide effect, and allelopathic properties. The extraction yield was about 14.3 and 7.14% for grounded and ungrounded seeds, respectively. The GC-MS analysis allowed the identification of 17 heterogeneous compounds, including eugenol (68.7-87.4%), as major compound, cyperene (20.5-7.2%), phenethyl isovalerate (6.4-3.6%), and cis-thujopsene (1.9-0.8%), respectively, for grounded and ungrounded seeds. Concerning the antibacterial activity, the diameter of the inhibition zone reached 35 mm when the essential oil extracted from grounded seeds was applied against Escherichia coli. Regarding the antioxidant activity via the DPPH radical scavenging test, the IC50 varied from 1.2 ± 0.1 to 2.8 ± 0.5 µg/mL. With respect to reducing power, the efficient concentration EC50 ranged from 32 to 50 µg/mL. The essential oil exhibited also an allelopathic effect against seeds of Hyoscyamus niger, as well as an insecticide effect against Sitophilus oryzae with a DL50 value of 252.4 µL/L air. These findings enhance the use of this spice as a natural food preservative and encourage its use in several fields, including pharmaceutical, cosmetics, agriculture, and therapy, that could be a strategic way to guarantee the consumer's health.

Apoptosis-like cell death upon kinetoplastid induction by compounds isolated from the brown algae Dictyota spiralis.

BACKGROUND: The in vitro activity of the brown seaweed Dictyota spiralis against both Leishmania amazonensis and Trypanosoma cruzi was evaluated in a previous study. Processing by bio-guided fractionation resulted in the isolation of three active compounds, classified as diterpenes. In the present study, we performed several assays to detect clinical features associated to cell death in L. amazonensis and T. cruzi with the aim to elucidate the mechanism of action of these compounds on parasitic cells. METHODS: The aims of the experiments were to detect and evaluate specific events involved in apoptosis-like cell death in the kinetoplastid, including DNA condensation, accumulation of reactive oxygen species and changes in ATP concentration, cell permeability and mitochondrial membrane potential, respectively, in treated cells. RESULTS: The results demonstrated that the three isolated diterpenes could inhibit the tested parasites by inducing an apoptosis-like cell death. CONCLUSIONS: These results encourage further investigation on the isolated compounds as potential drug candidates against both L. amazonensis and T. cruzi.

Triacylglycerols Profiles Established by UHPLC-ESI-MS in Developing Sweet, Semi-sweet and Bitter Seeds from Tunisian Oilseeds Apricot (Prunus armeniaca L.).

The aim of the present research is to investigate the effect of three harvest date on the composition of apricot seed. Indeed, triacylglycerols (TAGs) content and composition were studied in developing Tunisian apricot varieties bitter (Bargoug), semi-sweet (Oud Rhayem) and sweet (Chechi Bazza) cultivars at intervals of early (14 DAP), mid phase (28 DAP) and full phase (55 DAP) of oil accumulation by UHPLC-ESI-MS method. Eleven molecular species of triacylglycerols were detected and identified as LLL, LLO, LLP, LOO, LLS/LOP, LPP, OOO, LOS, OOP, POP and OOS. At 14 DAP, LLO was the major TAGs molecular species with 35.4-52.6% (maximum reached in semi-sweet apricot). Others major TAGs were founded at lower content as LOO (17.5-40.3%) and OOO (5.7-12.7%). However, among maturity, three distinct profiles of TAGs molecular species were observed: bitter apricot was significantly richer in OOO molecular species than cultivars ones. However, semi-sweet and sweet cultivars were richer in LLO and LOO molecular species at different time-dates. These latter may provide a schedule for harvesting Tunisian apricot seeds with high quality of oil content.

Density Functional Theory Investigation of the Binding of ThioTEPA to Purine Bases: Thermodynamics and Bond Evolution Theory Analysis.

Density functional theory with the ωB97X-D exchange-correlation functional together with implicit as well as explicit solvation is used to describe the reactions of the adenine and guanine purine bases on N,N',N″-triethylenethiophosphoramide (thioTEPA), an alkylating agent used as an anticancer drug. This reaction is decomposed into (i) a nucleophilic addition and (ii) a proton "migration" that is mediated by the solvent molecules. The calculations reveal that the first step is rate determining and that the presence of an explicit water molecule to mediate the proton migration has a negligible role on the kinetics of the first step, so that the focus is set on the first step of the reaction. ωB97X-D calculations highlight (i) the activation energy (Gibbs free enthalpy) is smaller for imine nitrogens than amine nitrogens, (ii) for the imine functions, the activation energy is slightly smaller for adenine than for guanine together with a larger exergonicity for the alkylation by adenine, and (iii) among the amine nitrogens, the presence of stabilizing H-bonds in the case of exocyclic amines leads to smaller activation energy than for the endocyclic ones. The reaction mechanisms are unraveled by employing the bond evolution theory, combining the use of electronic localization functions, and their evolution along the intrinsic reaction coordinate, with Thom's catastrophe theory. These analyses, suitable for highlighting the populations of the major monosynaptic and disynaptic basins, show (i) the reaction with imine nitrogens begins by the cleavage of the C-N aziridine bond and is followed by the simultaneous formation of the new C-N bond and the disappearance of the nitrogen lone pair, (ii) the reaction with the nitrogen atom of an endocyclic or exocyclic amine proceeds first by the formation of the cross-linking C-N bond and then by the cleavage of the C-N aziridine bond and the disappearance of the nitrogen lone pair, and (iii) in case ii, this bond breaking and forming occur before the transition state, which has been correlated to the increased Gibbs enthalpy of activation with respect to the reaction with the nitrogen atom of imine functions.

Effect of the Chemical Composition of Free-Terpene Hydrocarbons Essential Oils on Antifungal Activity.

In this study, Carum carvi L. essential oil (CEO) and Origanum majorana L. essential oil (MEO) was steam-distillated under reduced pressure. We henceforth obtained three fractions for each essential oil: CF1, CF2, CF3, MF1, MF2, and MF3. Then, these fractions were characterized using the gas chromatography-mass spectrometry (GC-MS) technique. The results indicated that some fractions were rich in oxygenated compounds (i.e., CF2, CF3, MF2, and MF3) with concentrations ranging from 79.21% to 98.56%. Therefore, the influence of the chemical composition of the essential oils on their antifungal activity was studied. For this purpose, three food spoilage fungi were isolated, identified, and inoculated in vitro, in order to measure the antifungal activity of CEO, MEO, and their fractions. The results showed that stronger fungi growth inhibitions (FGI) (above 95%) were found in fractions with higher percentages of oxygenated compounds, especially with (-)-carvone and terpin-4-ol as the major components. Firstly, this work reveals that the free-terpenes hydrocarbons fractions obtained from MEO present higher antifungal activity than the raw essential oil against two families of fungi. Then, it suggests that the isolation of (-)-carvone (97.15 ± 5.97%) from CEO via vacuum distillation can be employed successfully to improve antifungal activity by killing fungi (FGI = 100%). This study highlights that separation under reduced pressure is a simple green method to obtain fractions or to isolate compounds with higher biological activity useful for pharmaceutical products or natural additives in formulations.

Theoretical Assessment of the Second-Order Nonlinear Optical Responses of Lindqvist-Type Organoimido Polyoxometalates.

The second-order nonlinear optical properties of Lindqvist-type organoimido polyoxometalates bearing donor and acceptor substituents are evaluated by employing density functional theory and time-dependent density functional theory using the ωB97X-D range-separated hybrid exchange-correlation functional to describe accurately the field-induced effects. The hyper-Rayleigh scattering responses, ßHRS (-2ω; ω, ω), and the depolarization ratio are the targeted quantities. They are analyzed by resorting to the two-state model, which reduces the full summation-over-state expression to a single diagonal term and relates the response to a few spectroscopic quantities. The validity of this model is demonstrated by its ability to reproduce the ßHRS variations as a function of the nature of the ligand, owing to the dominant 1D character of these organic-inorganic hybrids. The calculated values are in good agreement with the recent experimental work of Al-Yasari et al. (Inorg. Chem. 2017, 56, 10181-10194), which demonstrates that the hexamolybdate moiety plays the role of an electron acceptor group. On the contrary, they contradict previous studies, which attributed an electron donor character to the polyoxometalate moiety. Calculations highlight that (i) combining the hexamolybdate unit with an organic ligand bearing a strong donor substituent leads to an enhanced first hyperpolarizability, associated with a dominant low-energy excited state, characterized by a large excitation-induced electron transfer from the donating ligand to the hexamolybdate, therefore coupling the polyoxometalate (POM) and its substituted ligand; (ii) in the case of weaker donor substituents, the hexamolybdate still behaves as an electron acceptor, but the first hyperpolarizability is smaller and the coupling has a reduced spatial extension; and, on the contrary, (iii) in the presence of an acceptor substituent, there is a competition between the hexamolybdate and this group so that the first hyperpolarizability becomes very small. The whole set of results demonstrates that polyoxometalate moieties are good candidates to achieve large second-order nonlinear optical (NLO) responses while keeping a rather large transparency window and also that there remains space to improve their integration into NLO efficient organic-inorganic hybrids.

Screening of Glycerophospholipids Molecular Species Contents in Three North African Apricot (Prunus armeniaca L.) Seed Varieties.

In the present work, a high-performance liquid chromatographic method coupled with mass spectrometry (HILIC-HPLC /ESI-MS) was used for the characterization and the quantification of glycerophospholipids (GPLs) classes and their molecular species in three genetically different Tunisian apricot cultivars (bitter, sweet and semi-sweet apricots). The application of the proposed method to the analysis of apricot oil allowed to separate and identify 74 molecular species of GPLs. Phosphatidylcholine (PC) class was found to be the most abundant GLPs in the three seed oils (38.6-62.4%) especially in bitter apricot, followed by phosphatidylinositol (PI) and phosphatidylethanolamine (PE) classes with values of 8.3-38.9% and 1.7-25.4% respectively. Phosphatidic acid (PA), phosphatidylglycerol (PG) and lysophosphatidylcholine (LPC) compounds were minor ones with maximums of 11.3%, 9.8% and 9.2% respectively. The results we obtained for the three Tunisian apricot seed varieties clearly indicate that the phospholipids of Tunisian apricot are of great interest. In fact, the high content of phosphatidylcholine (PC) determines it as a suitable and valuable source for obtaining corresponding phospholipids concentrates.

Spiralyde A, an Antikinetoplastid Dolabellane from the Brown Alga Dictyota spiralis.

Bioassay-guided fractionation of the antikinetoplastid extract of the brown alga Dictyota spiralis has led to the isolation of spiralyde A (1), a new dolabellane aldehyde, along with other five known related diterpenes (2⁻6). Their structures were determined by HRESIMS, 1D and 2D NMR spectroscopy, and comparison with data reported in the literature. The antiparasitic activity of all compounds was evaluated. Spiralyde A (1) and the known compound 3,4-epoxy-7,18-dolabelladiene (2) were the most active compounds against Leishmania amazonensis and Trypanosoma cruzi. Spiralyde A (1) was the most potent compound, comparable to benznidazole, the reference drug for trypanocidal activity.