9 documents found, page 1 of 1
Improving bio-oil fractions through fractional condensation of pyrolysis vapors...
Vilas-Boas, A.C.M.; Tarelho, L.; Marques, C.C.; Moura, J.M.O.; Santos, M.C.; Paradela, Filipe; Nunes, M.I.; Silvestre, A.J.D.ABSTRACT: Bio-oil produced from the pyrolysis of lignocellulosic biomass has potential as a biofuel or chemical precursor. However, its valorization is hindered by its complex composition, high water concentration, and the presence of oxygenated compounds. Operational strategies are therefore required to improve its quality. This study evaluated the technical feasibility of fractional condensation as an alterna...
Elderberry Stalks as a Source of High-Value Phytochemical: Essential Minerals a...
Patinha, Samuel; Murteira, Juliana V.; Costa, Carina Pedrosa; Salvador, Ângelo C.; Santos, Sónia A.O.; Silvestre, A.J.D.; Rocha, Sílvia M.Elderberry (Sambucus nigra L.) consumption has been growing in the last years, generating a large number of stalks (~10% of the berries bunch) that are still under-valorized. This study focused on the evaluation of elderberry stalks as a source of high-value phytochemicals. In this vein, the essential mineral content and lipophilic composition were analyzed for the first time. In addition, the polar fraction wa...
Development of Enzymatic Variants for the Synthesis of Bioresorbable Polyesters
Almeida, B. C.; Figueiredo, P. R.; Dourado, D. F. A. R.; Paul, S.; Sousa, Andreia F.; Silvestre, A.J.D.; Quinn, D.J.; Moody, T.S.; Carvalho, A.T.P.Enzymatic synthesis of polymeric materials is a powerful approach to make these processes greener, more economical, and safer for scale-up. Herein, we characterized new variants of the hyperthermophilic carboxylesterase from the archaeon Archaeoglobus fulgidus with quantum mechanics/molecular mechanics molecular dynamics simulations. The designed variants were expressed and tested for the synthesis of poly(ϵ-ca...
Structural characterization of stalk lignin from banana plant
Oliveira, L.; Evtuguin, D.; Cordeiro, N.; Silvestre, A.J.D.Dioxane lignins from two fractions of banana plant ‘Dwarf Cavendish’ stalk (floral stalk (DLFS) and rachis (DLR)) were structurally characterized by a set of spectroscopic (Ultravio let (UV), FTIR, solid- and liquid-state NMR) and chemical degradation (permanganate (PO) and nitrobenzene oxidation (NO)) techniques. Despite both lignins are of HGS-type, strong structural differences were observed between them. Th...
Structural characterization of stalk lignin from banana plant
Oliveira, L.; Evtuguin, D.; Cordeiro, N.; Silvestre, A.J.D.Dioxane lignins from two fractions of banana plant 'Dwarf Cavendish' stalk (floral stalk (DL(FS)) and rachis (DL(R))) were structurally characterized by a set of spectroscopic (Ultraviolet (UV), FTIR, solid- and liquid-state NMR) and chemical degradation (permanganate (PC) and nitrobenzene oxidation (NO)) techniques. Despite both lignins are of HGS-type, strong structural differences were observed between them....
Chemical composition of different morphological parts from ‘Dwarf Cavendish’ ba...
Oliveira, L.; Cordeiro, N.; Evtuguin, D.V.; Torres, I. C.; Silvestre, A.J.D.The study on chemical composition and structure of components from different morphological parts of ‘Dwarf Cavendish’ banana plant (petioles/midrib, leaf blades, floral stalk, leaf sheaths and rachis) have been carried out aiming to evaluate their potential as eventual raw materials for the chemical processing. Macromolecular components were analysed using solid-state NMR, ATR-FTIR and wet chemistry methods. Mi...
Lipophilic extractives from different morphological parts of banana plant “Dwar...
Oliveira, L.; Freire, C.S.R.; Silvestre, A.J.D.; Cordeiro, N.; Torres, I. C.; Evtuguin, D.The chemical composition of the dichloromethane extracts of different morphological parts of banana plant “Dwarf Cavendish”, cultivated in Madeira Island (Portugal), were studied by gas chromatography–mass spectrometry. The five different morpholog ical fractions in study have a similar qualitative chemical composition. Fatty acids and sterols are the major families present in the lipophilic extract of “Dwarf C...
Steryl glucosides from banana plant Musa acuminata Colla var cavendish
Oliveira, L.; Freire, C.S.R.; Silvestre, A.J.D.; Cordeiro, N.; Torres, I. C.; Evtuguin, D.The chemical composition of the dichloromethane extracts of several vegetal fractions of banana plant, Musa acuminata Colla var cavendish have been studied by GC–MS. Several bioactive steryl glucosides, namely campesteryl 3- -d-glucopyranoside, stigmasteryl 3- -d-glucopyranoside and sitosteryl 3- -d-glucopyranoside were identified as the major components of the ex tracts, accounting for 838.4–1824.3 mg/kg of th...
Cork suberin as a new source of chemicals.: 1. isolation and chemical character...
Cordeiro, N.; Belgacem, M.N.; Silvestre, A.J.D.; Pascoal Neto, C.; Gandini, A.Extractive-free cork from Quercus suber L. was submitted to a solvolysis treatment with methanolic NaOH which yielded 37% (o.d. cork) of suberin. This mixture of compounds was thoroughly characterized by FTIR, 1 H- and 13C-NMR, gas chromatogra phy coupled with mass spectrometric (GC–MS) analysis, vapour pressure osmometry (VPO), mass spectrography (MS) and gel permeation chromatography (GPC). After derivatizati...