23 research outputs found

    Choline-based eutectic mixtures as catalysts for effective synthesis of cyclic carbonates from epoxides and CO2

    Get PDF
    CO2 is a renewable, abundant and cheap C1-feedstock and its conversion to cyclic carbonates starting from epoxides has been widely explored in the last years. Nevertheless, conducting this reaction under mild and sustainable conditions is still a challenging task. Herein we present the use of choline-salt based eutectic mixtures as catalysts for the reaction of CO2 with epoxides to give cyclic carbonates. Choline chloride and choline iodide have been coupled with various hydrogen bond donors (HBDs), mainly cheap and bio-based carboxylic acids and polyols, to form two classes of eutectic mixtures. Very good yields were achieved under mild conditions (80 \u25e6C in 7\u201322 h) for various terminal epoxides, with both classes of catalysts. While a pressure of 0.4 MPa of CO2 is required to obtain appreciable conversions using choline chloride-based mixture, atmospheric pressure of CO2 (balloon) has been successfully used with choline iodide-based mixtures. Furthermore, the catalysts could be recycled without appreciable loss of the catalytic activity. The improved catalytic performance of both cholinebased eutectic mixtures is attributed to the synergistic activity of the halide, responsible for the opening of the epoxy-ring, and the HBD that has a role in the stabilization of the alkoxide intermediate

    Grape pomace for topical application: Green nades sustainable extraction, skin permeation studies, antioxidant and anti-inflammatory activities characterization in 3d human keratinocytes

    Get PDF
    Food waste is a global problem due to its environmental and economic impact, so there is great demand for the exploitation of new functional applications. The winemaking process leads to an incomplete extraction of high-value compounds, leaving the pomace still rich in polyphenols. This study was aimed at optimising and validating sustainable routes toward the extraction and further valorisation of these polyphenols, particularly for cosmeceutical applications. New formulations based on red grape pomace polyphenols and natural deep eutectic solvents (NaDESs) were here investigated, namely betaine combined with citric acid (BET-CA), urea (BET-U) and ethylene glycol (BET-EG), in which DESs were used both as extracting and carrying agents for polyphenols. The flavonoid profile determined by HPLC-MS/MS analysis showed similar malvidin content (51\u201356 \ub5g mL 121 ) in the DES combinations, while BET-CA gave the best permeation performance in Franz cells, so it was further investigated in 3D human keratinocytes (HaCat spheroids) injured with the pro-oxidant agent menadione. BET-CA treatment showed good intracellular antioxidant activity (IC50 0.15 \ub1 0.02 \ub5g mL 121 in malvidin content) and significantly decreased (p < 0.001) the release of the pro-inflammatory cytokine IL-8, improving cell viability. Thus, BET-CA formulation is worthy of investigation for potential use as a cosmetic ingredient to reduce oxidative stress and inflammation, which are causes of skin aging

    Ionic Liquids and their Biological Effects Towards Microorganisms

    No full text
    In this review an overview on the biological effects of ILs towards microorganisms is presented. Microorganisms are ideal indicators for investigating ILs' toxic effects towards organisms because of their large environmental, ecological and industrial relevance, and their short generation times and quick growth, useful for developing fast and easy toxicity assays. Herein the achievements in the development of ILs as biocides are described by taking into account the antimicrobic activity towards pathogenic microbes; the evaluation of ILs' environmental risk is dealt with the main results obtained by using model eukaryotic and prokaryotic microorganisms; and the current status on the use of ILs as biocompatible solvents for bioprocesses is outline

    Nutrient Removal Efficiency and Physiological Responses of Desmodesmus communis at Different HRTs and Nutrient Stress Condition Using Different Sources of Urban Wastewater Effluents

    No full text
    The objective of the present study was to evaluate the nutrient removal efficiency and the physiological responses in terms of growth, biochemical composition and photosynthetic activity of the autochthonous freshwater algal strain Desmodesmus communis. Microalgae were grown in a primary municipal effluent under different hydraulic retention times (HRTs) and in a two-phases process using both primary and secondary wastewater effluents. Semi-continuous cultures were operated for 7 day at 5-, 3- and 1.5-day HRT and the different dilution rate showed a greater influence on the biomass composition and nutrient removal efficiency. Removal of N-NH3 and P-PO4 was over 99 % and the highest accumulation of polysaccharides (57.2 wt.%) was obtained at high HRT (5 day); the maximum content of proteins (26.9 wt.%) was achieved at 1.5-day HRT, even if, under this condition, a clear inefficiency in terms of ammonia removal was observed. Moreover the accumulation of NNH3 occurring at 1.5-day HRT caused the decrease of the photosynthetic response in terms of efficiency of light capture (\u3b1) and relative electron transport rate (rETR), both parameters extracted from the rapid light curves (RLC) measurements. No significant differences were observed for the total fatty acids (TFAs), with a content of 2-3.5 wt.% for each HRT condition. On the other hand, in the two-phases process, when a nutrient deprivation condition was induced by diluting the culture with the secondary wastewater effluent, the algal cells accumulated TFAs, achieving a maximum content of 9.7 wt.% and a great increment in terms of biomass (1.64\ub10.02 g L-1) due to the ability of this algal strain to accumulate intracellular N. The wide and accurate investigation of the different aspects related to the whole process represents a relevant point of novelty in this research field and suggests the operational conditions for the start-up of an open pond system for wastewater treatment and biomass production for further applications

    Procedimento per il trasferimento di acidi grassi volatili tramite una membrana liquida a base organica

    No full text
    Viene descritto un procedimento per il trasferimento di acidi organici da una soluzione acquosa di alimentazione proveniente da un reattore di fermentazione anaerobica ad una soluzione acquosa tramite l\u2019ausilio di una membrana liquida a base organica immiscibile con tali fasi acquose, preferibilmente in cui tale soluzione acquosa di alimentazione presenta un pH inferiore rispetto al pH della soluzione acquosa ricevente; viene descritto altres\uec un sistema per l\u2019esecuzione di tale procedimento

    Metodo per separare e recuperare polietilene e alluminio da un materiale poliaccoppiato

    No full text
    L\u2019invenzione fa riferimento ad una nuova tecnologia a base di switchable hydrophilic solvents (SHS) per la separazione e recupero di polietilene a bassa densit\ue0 (LDPE) e alluminio da imballaggi alimentari (poliaccoppiato). Il nuovo metodo, interamente sostenibile, consente il recupero di entrambi i materiali in elevate quantit\ue0 (> 99% per l'alluminio e > 80% per il polietilene) e buona qualit\ue0 ( 65 86% di alluminio non ossidato). L\u2019invenzione appartiene agli approcci chimici per separare LDPE e alluminio da residui sminuzzati di poliaccoppiat

    Valorizzazione di materiali plastici a base di amido mediante pirolisi

    No full text
    L\u2019invenzione consente la gestione fine vita di plastiche a base di amido tramite processi termochimici come alternativa al compostaggio e alla digestione anaerobica. Il procedimento permette di recuperare e riciclare gli atomi e le funzionalit\ue0 presenti nelle plastiche a base di amido mediante depolimerizzazione e riarrangiamento, producendo nuovi composti chimici e materiali, in un\u2019ottica di economia circolare

    PUFAs and PUAs production in three benthic diatoms from the northern Adriatic Sea.

    No full text
    The production of polyunsaturated aldehydes (PUAs) has been reported by many planktonic diatoms, where they have been implicated in deleterious effects on copepod reproduction and growth of closeby microbes or suggested as infochemicals in shaping plankton interactions. This study investigates the production of PUAs by diatoms commonly occurring in the microphytobenthic communities in temperate regions: Tabularia affinis, Proschkinia complanatoides and Navicula sp. Results highlight the production of PUAs by the three benthic diatoms during stationary and decline phases, with intracellular concentrations from 1.8 to 154.4 fmol cell1, which are within the range observed for planktonic species. The existence of a large family of PUAs, including some with four unsaturations, such as decatetraenal, undecatetraenal and tridecatetraenal, was observed. Since particulate and dissolved PUAs were positively correlated, together with cell lysis, equivalent concentrations may be released during late growth stages, which may affect benthic invertebrates grazing on them and other microalgae

    Fast procedure for the analysis of poly(hydroxyalkanoates) in bacterial cells by off-line pyrolysis/gas-chromatography with flame ionization detector

    No full text
    Poly(hydroxyalkanoates) (PHAs) are polyesters formed by saturated short chain hydroxyacids, among which 3-hydroxybutanoic (HB) and 3-hydroxypentanoic (3-hydroxyvalerate, HV) are the most common monomers of homopolymers (e.g. poly(3-hydroxybutyrate), PHB) and copolymers (e.g. poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), PHB-HC). The most widely used approach for their determination is the polymer methanolysis followed by gas chromatography-mass spectrometry (GC-MS) analysis of the methylated monomers; this procedure generally requires the use of additional reagents (e.g. sulfuric acid) and is performed with harmful chlorinated solvents, such as chloroform. The development of fast routine solventless methods for the quantitative determination of PHAs and their monomeric composition is highly desirable to reduce sample pretreatment, speed up the analysis and decrease overall costs. It has been reported that under thermal treatment (e.g. pyrolysis, Py), PHAs are degraded in high yield (>40%, w/wPHA) into the corresponding 2-alkenoic acid (e.g. crotonic acid from PHB). This work aimed at investigating this reaction for direct analysis of PHAs in bacterial cells. The sample was directly subjected to pyrolysis and trapped pyrolysis products were analyzed by GC-FID. Off-line Py/GC-FID was first optimized on pure polymers with different monomer composition (PHB, PHB-HV, PHB-HC) and then applied to bacterial samples deriving from both mixed microbial cultures or selected strains, containing various types and amounts of PHAs. The Py/GC-FID method provided RSD <15% range, limit of detection of 100\u3bcg (1% PHAs in biomass), and results comparable to that of methanolysis (R2=0.9855), but with minimal sample pretreatment
    corecore