9 documents found, page 1 of 1
Transcriptomic and metabolomic profiling of ionic liquid stimuli unveils enhanc...
Alves, Paula C.; Hartmann, Diego O.; Núñez, Oscar; Martins, Isabel; Gomes, Teresa L.; Garcia, Helga; Galceran, Maria Teresa; Hampson, RichardThe inherent potential of filamentous fungi, especially of Ascomycota, for producing diverse bioactive metabolites remains largely silent under standard laboratory culture conditions. Innumerable strategies have been described to trigger their production, one of the simplest being manipulation of the growth media composition. Supplementing media with ionic liquids surprisingly enhanced the diversity of extracel...
Elucidating how the saprophytic fungus Aspergillus nidulans uses the plant poly...
Martins, Isabel; Hartmann, Diego O; Alves, Paula C; Martins, Celso; Garcia, Helga; Leclercq, Céline C; Ferreira, Rui; He, Ji; Renaut, JennyLipid polymers in plant cell walls, such as cutin and suberin, build recalcitrant hydrophobic protective barriers. Their degradation is of foremost importance for both plant pathogenic and saprophytic fungi. Regardless of numerous reports on fungal degradation of emulsified fatty acids or cutin, and on fungi-plant interactions, the pathways involved in the degradation and utilisation of suberin remain largely o...
Ex Situ Reconstitution of the Plant Biopolyester Suberin as a Film
Garcia, Helga; Ferreira, Rui; Martins, Celso; Sousa, Andreia F.; Freire, Carmen S. R.; Silvestre, Armando J. D.; Kunz, Werner; Rebelo, Luis Paulo N.Biopolymers often have unique properties of considerable interest as a basis for new materials. It is however not evident how to extract them from plants without destroying their chemical skeleton and inherent properties. Here we report the ex situ reconstitution of the biopolyester suberin as a new waterproof and antimicrobial material. In plant cell walls, suberin, a cross-linked network of aromatic and aliph...
Unveiling the dual role of the cholinium hexanoate ionic liquid as solvent and ...
Ferreira, Rui; Garcia, Helga; Sousa, Andreia F.; Guerreiro, Marina; Duarte, Filipe J. S.; Freire, Carmen S. R.; Calhorda, Maria JoseDisruption of the three-dimensional network of suberin in cork by cholinium hexanoate leads to its efficient and selective isolation. The reaction mechanism, which likely involves selective cleavage of some inter-monomeric bonds in suberin, was still unanswered. To address this question, the role of the ionic liquid during suberin depolymerisation and during cleavage of standard compounds carrying key chemical ...
Cholinium-based Supported Ionic Liquid Membranes: A Sustainable Route for Carbo...
Tome, Liliana C.; Patinha, David J. S.; Ferreira, Rui; Garcia, Helga; Pereira, Cristina Silva; Freire, Carmen S. R.; Rebelo, Luis Paulo N.Aiming at full sustainability of CO2 separation processes, a series of supported ionic liquid membranes based on environmentally friendly cholinium carboxylate ionic liquids were successfully prepared. Their gas permeation properties were measured and high permselectivities were obtained for both CO2/CH4 and CO2/N-2.
Isolation of suberin from birch outer bark and cork using ionic liquids: A new ...
Ferreira, Rui; Garcia, Helga; Sousa, Andreia F.; Freire, Carmen S. R.; Silvestre, Armando J. D.; Rebelo, Luis Paulo N.; Pereira, Cristina SilvaCholinium hexanoate, a biocompatible and biodegradable ionic liquid, was recently demonstrated to efficiently and selectively extract suberin domains from cork, combining high extraction efficiency with isolation of a partial depolymerised material. In the present paper, we report a comparative study of the characterisation of suberin extracted from birch outer bark and from cork using cholinium hexanoate. It b...
Effect of natural and synthetic antioxidants incorporation on the gas permeatio...
Goncalves, Carla M. B.; Tome, Liliana C.; Garcia, Helga; Brandao, Lucia; Mendes, Adelio M.; Marrucho, Isabel M.Gas permeation properties (permeability, diffusivity and solubility coefficients) were determined for carbon dioxide and oxygen in poly(lactic acid) (PLA) films enriched with 0, 2, 4 and 10 wt.% of different antioxidants, at three temperatures, 284, 293 and 303 K, using a time-lag apparatus. Three antioxidants, a natural, alpha-tocopherol (AT), and two synthetic, butylated hydroxytoluene (BHT) and tert-butylhyd...
Microwave assisted extraction of betulin from birch outer bark
Ferreira, Rui; Garcia, Helga; Sousa, Andreia F.; Freire, Carmen S. R.; Silvestre, Armando J. D.; Kunz, Werner; Rebelo, Luis Paulo N.In this communication, we report a new method for the isolation of betulin, a triterpenoid with interesting pharmacological activities, from birch outer bark. Remarkably high purity betulin raw extracts were obtained, ca. 95 wt%, through microwave assisted extraction with limonene. This saves time and energy when compared to the conventional methods.
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR ...
Garcia, Helga; Barros, António; Gonçalves, Catarina; Gama, F. M.; Gil, Ana M.Fourier transform infrared (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectroscopy were used to study dextrin structural changes occurring upon hydrogel formation by vinyl acrylate (VA) grafting and subsequent free radical polymerization. The degrees of VA substitution (DS) and polymerization (DP) were quantified up to 40%VA by FTIR intensity measurements and partial least squares (PLS)/FTIR, t...