287 research outputs found

    Comprehensive Insight into the Elderflowers and Elderberries (Sambucus nigra L.) Mono and Sesquiterpenic Metabolites: Factors that Modulate Their Composition

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    Plant secondary metabolites are synthesized for their protection and regulation purposes. Quite often, due to their properties, these metabolites have relevant organoleptic and biological properties and can play important roles in human health and general well-being. A relevant case study in this context is berries and flowers from Sambucus nigra L., which have been used for generations in folk medicine. Although those effects are mainly linked to phenolic compounds, mono and sesquiterpenic secondary metabolites may also play a key role. Despite their potential, S. nigra mono and sesquiterpenic compounds are yet largely unexplored. Complex and dynamic external and internal plant-related phenomena deeply affect terpenes profile, as metabolism, abiotic and biotic stresses, and understanding these phenomena is the first step for S. nigra berries and flowers’ valuation. This chapter will cover aspects linked to elder plant uses, mono and sesquiterpenic composition, and the influence of preharvest and postharvest effects over these metabolites. This knowledge is crucial for scientists and industries to understand and improve the quality of S. nigra-based products

    Determination of the Hydroxy and Carboxylic Acid Groups in Natural Complex Mixtures of Hydroxy Fatty Acids by (1)H Nuclear Magnetic Resonance Spectroscopy

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    The use of trichloroacetyl isocyanate (TAI) to mark both hydroxyl and carboxyl groups borne by the hydrolysis or methanolysis of suberin fragments (a complex mixture of hydroxy fatty acids), allowed the quantitative assessment of the ratio between carboxyl and hydroxy groups, as well as the ratio between primary and secondary hydroxy groups, to be carried out reliably by (1)H nuclear magnetic resonance (NMR) spectroscopy. All the samples thus analyzed displayed an excess of CO(2)H (or CO(2)CH(3)) functions with respect to the OH counterparts, albeit to a variable extent, depending on the procedure adopted to isolate the suberin fragments. The precise knowledge of the molar ratio of these two reactive moieties is fundamental for the correct utilization of suberin monomers in polymerization reactions leading to aliphatic polyesters.FCT - SFRH/ BD/38890/200

    Nanocellulose-based antifungal nanocomposites against the polymorphic fungus Candida albicans

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    The design of functional materials capable of fighting fungal infections is of paramount importance given the intricate problem of multidrug-resistant pathogenic fungi. Herein, nanocomposites consisting of cross-linked poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (PMETAC) and bacterial nanocellulose (BNC) were prepared, characterized and tested towards the polymorphic fungus Candida albicans. The BNC three-dimensional network enabled the in-situ polymerization of the non-toxic and bioactive quaternary-ammonium monomer, which originated transparent nanocomposites containing 10 and 40 wt.% of cross-linked PMETAC. Furthermore, the nanocomposites exhibit UV-A and UV-B blocking properties, high water-uptake capacity, thermal stability up to 200 °C, good viscoelastic (storage modulus > 1.7 GPa) and mechanical (Young's modulus ≥2.4 GPa) properties and are non-cytotoxic to human keratinocytes (HaCaT cells). The fungal inactivation reached a 4.4 ± 0.14-log CFU reduction for the nanocomposite containing only 10 wt.% of cross-linked PMETAC. Hence, these bioactive and non-cytotoxic materials can constitute potentially effective systems for the treatment of C. albicans infections.publishe

    The role of ionic liquids in the pharmaceutical field: an overview of relevant applications

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    Solubility, bioavailability, permeation, polymorphism, and stability concerns associated to solid-state pharmaceuticals demand for effective solutions. To overcome some of these drawbacks, ionic liquids (ILs) have been investigated as solvents, reagents, and anti-solvents in the synthesis and crystallization of active pharmaceutical ingredients (APIs), as solvents, co-solvents and emulsifiers in drug formulations, as pharmaceuticals (API-ILs) aiming liquid therapeutics, and in the development and/or improvement of drug-delivery-based systems. The present review focuses on the use of ILs in the pharmaceutical field, covering their multiple applications from pharmaceutical synthesis to drug delivery. The most relevant research conducted up to date is presented and discussed, together with a critical analysis of the most significant IL-based strategies in order to improve the performance of therapeutics and drug delivery systems.publishe

    A compendium of current developments on polysaccharide and protein-based microneedles

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    Microneedles (MNs), i.e. minimally invasive three-dimensional microstructures that penetrate the stratum corneum inducing relatively little or no pain, have been studied as appealing therapeutic vehicles for transdermal drug delivery. Over the last years, the fabrication of MNs using biopolymers, such as polysaccharides and proteins, has sparked the imagination of scientists due to their recognized biocompatibility, biodegradability, ease of fabrication and sustainable character. Owing to their wide range of functional groups, polysaccharides and proteins enable the design and preparation of materials with tunable properties and functionalities. Therefore, these biopolymer-based MNs take a revolutionary step offering great potential not only in drug administration, but also in sensing and response to physiological stimuli. In this review, a critical and comprehensive overview of the polysaccharides and proteins employed in the design and engineering of MNs will be given. The strategies adopted for their preparation, their advantages and disadvantages will be also detailed. In addition, the potential and challenges of using these matrices to deliver drugs, vaccines and other molecules will be discussed. Finally, this appraisal ends with a perspective on the possibilities and challenges in research and development of polysaccharide and protein MNs, envisioning the future advances and clinical translation of these platforms as the next generation of drug delivery systems.publishe

    Relationship of chemical structures of textile dyes on the pre-adaptation medium and the potentialities of their biodegradation by Phanerochaete chrysosporium

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    Azo dye derivatives of azobenzene constitute the largest group of dyes used in the textile industry and possess recalcitrant chemical groups, such as those of azo and sulphonic acid. Some microorganisms are able to degrade these aromatic compounds. In the present work, decolourisation of culture media containing azo dyes by the ligninolytic fungus Phanerochaete chrysosporium was achieved under nitrogenlimited conditions. The dyes used in the study are derivatives of meta- or para-aminosulphonic or aminobenzoic acids and include in their structures groups such as guaiacol or syringol, which are bioaccessible to the lignin degrading fungus P. chrysosporium. The aim of this study was to pre-adapt the microorganism to the structure of the dyes and to establish the relationships of the chemical structure of the dye present in the pre-adaptation medium with the chemical structure of the dye to be degraded. The azo dye used in the pre-adaptation medium that gave the best overall decolourisation performance was a meta-aminosulphonic acid and guaiacol derivative. The azo dye derivative of a meta-aminobenzoic acid and syringol showed a better performance in the decolourisation assays. Preliminary GC-MS studies indicated the formation of a nitroso substituted catechol metabolite, a precursor of aromatic ring cleavage, which was confirmed to occur by an enzymatic assay. The presence of this type of metabolite allows the establishment of a possible metabolic pathway towards mineralisation.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI/BD/15878/98.Instituto de Biotecnologia e Química Fina (IBQF)

    Comparative studies of fungal degradation of single or mixed bioaccessible reactive azo dyes

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    A screening using several fungi (Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor and Aureobasidium pullulans) was performed on the degradation of syringol derivatives of azo dyes possessing either carboxylic or sulphonic groups, under optimized conditions previously established by us. T. versicolor showed the best biodegradation performance and its potential was confirmed by the degradation of differently substituted fungal bioaccessible dyes. Enzymatic assays (lignin peroxidase, manganese peroxidase, laccase, proteases and glyoxal oxidase) and GC-MS analysis were performed upon the assay obtained using the most degraded dye. The identification of hydroxylated metabolites allowed us to propose a possible metabolic pathway. Biodegradation assays using mixtures of these bioaccessible dyes were performed to evaluate the possibility of a fungal wastewater treatment for textile industries.Instituto de Biotecnologia e Química Fina (IBQF). Fundação para a Ciência e a Tecnologia (FCT) - Praxis XXI/BD/15878/98

    Expanding the Applicability of Poly(Ionic Liquids) in Solid Phase Microextraction: Pyrrolidinium Coatings

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    Crosslinked pyrrolidinium-based poly(ionic liquids) (Pyrr-PILs) were synthesized through a fast, simple, and solventless photopolymerization scheme, and tested as solid phase microextraction (SPME) sorbents. A series of Pyrr-PILs bearing three different alkyl side chain lengths with two, eight, and fourteen carbons was prepared, characterized, and homogeneously coated on a steel wire by using a very simple procedure. The resulting coatings showed a high thermal stability, with decomposition temperatures above 350 degrees C, excellent film stability, and lifetime of over 100 injections. The performance of these PIL-based SPME fibers was evaluated using a mixture of eleven organic compounds with different molar volumes and chemical functionalities (alcohols, ketones, and monoterpenes). The Pyrr-PIL fibers were obtained as dense film coatings, with 67 mu m thickness, with an overall sorption increase of 90% and 55% as compared to commercial fibers of Polyacrylate (85 mu m) (PA85) and Polydimethylsiloxane (7 mu m) (PDMS7) coatings, respectively. A urine sample doped with the sample mixture was used to study the matrix effect and establish relative recoveries, which ranged from 60.2% to 104.1%.David J. S. Patinha, and Liliana C. Tome are grateful to FCT (Fundacao para a Ciencia e a Tecnologia) for the PhD research grant SFRH/BD/97042/2013 and the Post-Doctoral research grant (SFRH/BPD/101793/2014), respectively. David J. S. Patinha also thanks the financial support from COST-Exil Project 1206. The NMR data was acquired at CERMAX (Centro de Ressonncia Magnetica Antnio Xavier) which is a member of the National NMR network. This work was partially supported by FCT through Research Unit GREEN-it " Bioresources for Sustainability" (UID/Multi/04551/2013) and the Associate Laboratory CICECO Aveiro Institute of materials (UID/CTM/50011/2013)

    Purple passion fruit (Passiflora edulis f. edulis): a comprehensive review on the nutritional value, phytochemical profile and associated health effects

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    Passiflora is a highly diverse genus where taxonomic lack of consensus remains. This may be the reason why numerous studies do not specify to the infraspecific level the plant material used or lack consistency in the nomenclature of botanical formae of Passiflora edulis. Ultimately, this may contribute to inaccurate chemical composition and health effects attributed to different Passiflora edulis species and formae. Hence, this review aims to overcome these challenges by exploring the phytochemical profile, specific nutritional value and potential health benefits of purple passion fruit (PPF). PPF is often consumed fresh for its pulp (including seeds) or juice, either directly or added to food dishes. It is also used industrially to produce a wide range of products, where peels and seeds are abundant by-products, most often discarded or used in low-value applications. Herein, in a perspective of integral valorisation of the fruit, the potential use of all PPF fractions (peel, pulp and seeds) is discussed as a source of important macro and micronutrients, adequate to integrate a balanced and healthy diet. In addition, the phytochemical profile of such fractions is also discussed along with the associated in vitro biological activities (antioxidant, anti-inflammatory, antibacterial and antifungal) and in vivo beneficial effects in the management of several diseases (asthma, hypertension, osteoarthritis, diabetes and pulmonary fibrosis). In summary, this review gathers the current knowledge on the nutritional and phytochemical composition of PPF and highlights the potential of using all fractions as a source of ingredients in food formulations that promote health and well-being. At the same time, it also contributes to defining sustainable strategies for an integrated valorisation of this natural product.publishe

    Novel insights into biomass delignification with acidic deep eutectic solvents: a mechanistic study of β-O-4 ether bond cleavage and the role of the halide counterion in the catalytic performance

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    The development of innovative technologies for an efficient, yet eco-friendly, biomass delignification is required to achieve higher sustainability than traditional processes. In this context, the use of deep eutectic solvents (DES) for the delignification process could fulfil these requirements and stands today as a promising alternative. This work focus on understanding the fundamental chemistry behind the cleavage of B-O-4 ether bond present in 2-phenoxy-1-phenylethanol (PPE), a lignin model compound, with three acidic DES, including Propionic acid/Urea (PA:U), Lactic acid/Choline Chloride (LA:ChCl) and p-Toluenesulphonic acid/Choline chloride (pTSA:ChCl). The acidic nature of each DES influenced the efficiency of PPE cleavage and determined the extent of further side reactions of cleavage products. Although PA:U (2:1) demonstrated ability to dissolve lignin, it is unable to cleave B-O-4 ether linkage in PPE. On the other hand, LA:ChCl (10:1) allowed PPE cleavage, but an esterification between the PPE and lactic acid as well as oligomerization of lactic acid were detected. Among examined solvents, pTSA:ChCl (1:1) demonstrated the highest performance on the PPE cleavage, although the high acidity of this system lead to condensation of cleavage products at prolonged time. The presence of water decreases the ability of DES for the cleavage, but the extension of undesired side reactions was also reduced. Finally, the analysis of intermediates and products of the reactions allowed the identification of a chlorinated species of PPE that precedes the cleavage reaction. A kinetic study using pTSA:ChCl (1:1) and pTSA:ChBr (1:1) was performed to unveil the role of the halide counterion present in DES on the cleavage of <2=2 ether bond and a new reaction mechanism was herein proposed and supported by density functional theory (DFT) calculations.Altri ñ Celbi, Buckman, Crown Van Gelder, CTP, DS Smith Paper, ESKA, Essity, Holmen, ISPT, Mayr-Melnhof Eerbeek, Mets‰ Fibre, Mid Sweden University, Mondi, Omya, The Navigator Company, Sappi, Essity, Smurfit Kappa, Stora Enso, Eindhoven University of Technology, University of Aveiro, University of Twente, UPM, Valmet Technologies Oy, Voith Paper, VTT Technical Research Centre of Finland Ltd, WEPA and Zellstoff Pols.in publicatio
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