Metabolic profile and biological activities of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco: Studies on the essential oil and polar extracts

We investigated the metabolic profile and biological activities of the essential oil and polar extracts of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco collected in south Portugal. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that oxygen-containing monoterpenes was the principal group of compounds identified in the essential oil. Camphor (40.6%) and fenchone (38.0%) were found as the major constituents. High-performance liquid chromatography with diode array detection (HPLC–DAD) analysis allowed the identification of hydroxycinnamic acids (3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and rosmarinic acids) and flavones (luteolin and apigenin) in the polar extracts, with rosmarinic acid being the main compound in most of them. The bioactive compounds from L. pedunculata polar extracts were the most efficient free-radical scavengers, Fe²⁺ chelators and inhibitors of malondialdehyde production, while the essential oil was the most active against acetylcholinesterase. Our results reveal that the subspecies of L. pedunculata studied is a potential source of active metabolites with a positive effect on human health.     

Morphological characterization and photocatalytic efficiency measurements of pure silica transparent open-cell sponges coated with TiO2

Transparent glass sponges are a new class of materials that can potentially be used for effective light distribution in photocatalytic applications. In this work, transparent glass sponges are prepared by the polymer replica technique and coated with TiO₂ to obtain a highly efficient photocatalytic material. Necessary conditions for obtaining transparent open-celled glass sponges are presented. The structure is characterized by employing light microscopy and scanning electron microscopy. In addition, µ-computer tomography (µ-CT) volume image analysis was performed that allows the calculation of geometrical parameters like pore size and specific surface area (SSA) of the structure, required for application of the new material. For photocatalytic application, the sponges have been coated with titanium dioxide (TiO₂) by immersion in a suspension of TiO₂ nanoparticles. The activity of the resulting coatings has been tested with the model reaction of transformation of Cr(VI) to Cr(III) in aqueous solutions in the presence of EDTA at pH 2. The reaction kinetics could be adjusted to a pseudo-first order reaction and the obtained rate constants have been employed to evaluate the photocatalytic activity. The activity of the sponges has been compared with that of samples of glass plates coated with TiO₂; it has been found that the sponges exhibited a higher catalytic activity than the glass plates. The photocatalytic activity increased with the porosity of the sponges, and the optimum sample was determined based on its photocatalytic performance and its mechanical stability. The results are promissory for application in photoreactors for transformation of pollutants in water and air decontamination.     

CpMo(CO)3Cl as a precatalyst for the epoxidation of olefins

The tricarbonyl complex CpMo(CO)₃C1 was found to act as a precatalyst for the reaction of tert-butyl hydroperoxide and olefins to yield the corresponding epoxides and diols. Under the reaction conditions, oxidative decarbonylation leads to the formation of the dioxo complex CpMoO₂Cl. The catalytic recyclability and the effect of temperature on the catalytic results have been examined, and a reaction mechanism proposed, supported by kinetic modelling.     

Swarm optimisation algorithms applied to large balanced communication networks

In the last years, several combinatorial optimisation problems have arisen in the computer communications networking field. In many cases, for solving these problems it is necessary the use of meta-heuristics. An important problem in communication networks is the Terminal Assignment Problem (TAP). Our goal is to minimise the link cost of large balanced communication networks. TAP is a NP-Hard problem. The intractability of this problem is the motivation for the pursuits of Swarm Intelligence (SI) algorithms that produce approximate, rather than exact, solutions. This paper makes a comparison among the effectiveness of three SI algorithms: Ant Colony Optimisation, Discrete Particle Swarm Optimisation and Artificial Bee Colony. We also compare the SI algorithms with several algorithms from literature. Simulation results verify the effectiveness of the proposed algorithms. The results show that SI algorithms provide good solutions in a better running time.     

Effects of Gamma Irradiation on the Chemical Composition and Antioxidant Activity of Lactarius deliciosus L. Wild Edible Mushroom

The short shelf-life of mushrooms is an obstacle to the distribution and marketing of the fresh product. There has been extensive research on finding the most appropriate technology for mushrooms preservation and a particular interest arises for wild species. Treatment by irradiation emerges as a possible conservation technique that has been tested successfully in several food products. Herein, the effects of gamma irradiation on Lactarius deliciosus (L. ex Fr.) S. F. Gray chemical composition and antioxidant activity were evaluated in samples submitted to different storage periods (0, 4 and 8 days) at 4 °C. The irradiation treatments were performed in a Co-60 experimental equipment. Nutritional value was accessed by macronutrients analysis and determination of energetic value; fatty acid, sugar and tocopherol profiles were determined by gas chromatography–flame ionization detector, high-performance liquid chromatography (HPLC) refractive index and HPLC fluorescence, respectively. The antioxidant activity was evaluated through radical scavenging activity, reducing power, lipid peroxidation inhibition and phenolics content. The obtained data show that, until 1 kGy, gamma irradiation might provide a useful alternative to ensure the quality and extend the life of mushrooms, since its effects on macronutrients, energetic value, tocopherols and antioxidant activity EC₅₀ values were less significant than the changes caused by storage time. Moreover, the chemical and nutritional composition was similar in irradiated and non-irradiated L. deliciosus samples.     

Clitocybe alexandri extract induces cell cycle arrest and apoptosis in a lung cancer cell line: Identification of phenolic acids with cytotoxic potential

Mushrooms are a possible rich source of biologically active compounds with the potential for drug discovery. The aim of this work was to gain further insight into the cytotoxicity mechanism of action of Clitocybe alexandri ethanolic extract against a lung cancer cell line (NCI-H460 cells). The effects on cell cycle profile and levels of apoptosis were evaluated by flow cytometry, and the effect on the expression levels of proteins related to cellular apoptosis was also investigated by Western blot. The extract was characterised regarding its phenolic composition by HPLC-DAD, and the identified compounds were studied regarding their growth inhibitory activity, by sulforhodamine B (SRB) assay. The effect of individual or combined compounds on viable cell number was also evaluated using the Trypan blue exclusion assay. It was observed that the C. alexandri extract induced an S-phase cell cycle arrest and increased the percentage of apoptotic cells. In addition, treatment with the GI₅₀ concentration (concentration that was able to cause 50% of cell growth inhibition; 24.8 μg/ml) for 48 h caused an increase in the levels of wt. p53, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP). The main components identified in this extract were protocatechuic, p-hydroxybenzoic and cinnamic acids. Cinnamic acid was found to be the most potent compound regarding cell growth inhibition. Nevertheless, it was verified that the concomitant use of the individual compounds provided the strongest decrease in viable cell number. Overall, evidence was found for alterations in cell cycle and apoptosis, involving p53 and caspase-3. Furthermore, our data suggests that the phenolic acids identified in the extract are at least partially responsible for the cytotoxicity induced by this mushroom extract.     

Catalytic olefin epoxidation with cationic molybdenum(VI) cis-dioxo complexes and ionic liquids

The complexes [MoO₂Cl(HC(bim)₃)]Y (Y = Cl (1), BF₄ (2) and PF₆ (3)) have been prepared by reaction of MoO₂Cl₂(THF)₂ (for 1) or [MoO₂Cl(THF)₃]Y (for 2 and 3) with the tridentate ligand HC(bim)₃ = tris(benzimidazolyl)methane, and characterized by IR and Raman spectroscopy, and ¹H NMR. The turnover frequencies for the epoxidation of cis-cyclooctene at 55 °C with tert-butyl hydroperoxide (TBHP, in decane) as the oxidant and complexes 1–3 as catalysts are in the range of 70–200 mol mol_Mo^?1 h^?1. 1,2-Epoxycyclooctane is always the only reaction product for reaction times up to 24 h. With the aim of facilitating the recyclability of the complexes, the ionic liquids (ILs) [BMIM]Y and [BMPy]Y (BMIM = 1-n-butyl-3-methylimidazolium, BMPy = 1-n-butyl-3-methylpyridinium; Y = BF₄ or PF₆) were applied as ionic solvents. The catalytic performance for cyclooctene epoxidation depends strongly on the catalyst solubility in the IL. Of the 12 catalyst/IL mixtures examined, the systems 1/[BMIM]PF₆ and 1/[BMPy]PF₆ exhibit the most favorable reaction rates allied with good recyclability. The 1/[BMIM]PF₆ system was further applied using different oxidants (aqueous TBHP, aqueous H₂O₂ and urea–hydrogen peroxide adduct) and olefins (norbornene, cyclohexene, styrene, α-pinene).     

Thermorheological and Textural Behaviour of Gluten-Free Gels Obtained from Chestnut and Rice Flours

Nowadays, as celiac disease is becoming more common the consumers’ demand for gluten-free products with high nutritional and taste quality is increasing. This work deals with the study of the impact of four novelty gluten-free sources: chestnut flour (Cf), whole rice flour (Rw), Carolino rice flour (Rc) and Agulha rice flour (Ra). Textural, thermorheological and stability performance of gluten-free gels using different experimental techniques were evaluated. Mixed gels were also produced for comparison. Texture parameters were determined from the texture profile analysis using a texturometer. Thermorheological oscillatory measurements were conducted in a stress-controlled rheometer in order to clarify the kinetics of gel formation and to characterise the structure of the matured gels. The stability of the gels was evaluated using transmittance profiling of the gels under gravitational fields (LUMiSizer®). Texture studies suggested that gels from mixtures of chestnut flour at 30 % and rice flour at 20 % showed the right texture to develop gel-based new desserts. Rheological results showed that the thermal profiles on heating of Cf gels were similar to those obtained for Rw and Ra, whereas Rc gels exhibited a particular pattern. Once the final gelatinisation temperature was achieved, no significant differences on the viscoelastic properties were noticed for all the tested gels. Stability tests showed that gels with Rc should present an industrial advantage over the other assayed formulations, since the stability of these gels is of the order of four times larger.