Associated Laboratory for Green Chemistry - Clean Technologies and Processes

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Publications

Copper Complexes with 1,10-Phenanthroline Derivatives: Underlying Factors Affecting Their Cytotoxicity

Publication . Nunes, Patrique; Correia, Isabel; Marques, Fernanda; Matos, Antonio Pedro; dos Santos, Margarida M. C.; Azevedo, Cristina G.; Capelo, Jose-Luis; Santos, Hugo M.; Gama, Sofia; Pinheiro, Teresa; Cavaco, Isabel; Pessoa, Joao Costa

The interpretation of in vitro cytotoxicity data of Cu(II)-1,10-phenanthroline (phen) complexes normally does not take into account the speciation that complexes undergo in cell incubation media and its implications in cellular uptake and mechanisms of action. We synthesize and test the activity of several distinct Cu(II)-phen compounds; up to 24 h of incubation, the cytotoxic activity differs for the Cu complexes and the corresponding free ligands, but for longer incubation times (e.g., 72 h), all compounds display similar activity. Combining the use of several spectroscopic, spectrometric, and electrochemical techniques, the speciation of Cu-phen compounds in cell incubation media is evaluated, indicating that the originally added complex almost totally decomposed and that Cu(II) and phen are mainly bound to bovine serum albumin. Several methods are used to disclose relationships between structure, activity, speciation in incubation media, cellular uptake, distribution of Cu in cells, and cytotoxicity. Contrary to what is reported in most studies, we conclude that interaction with cell components and cell death involves the separate action of Cu ions and phen molecules, not [Cu(phen)(n)] species. This conclusion should similarly apply to many other Cu-ligand systems reported to date.

2020-07Journal article

Open access

New deep eutectic solvent assisted extraction of highly pure lignin from maritime pine sawdust (Pinus pinaster Ait.)

Publication . Fernandes, Catarina; Melro, Elodie; Magalhaes, Solange; Alves, Luis; Craveiro, Rita; Filipe, Alexandra; Valente, Artur J. M.; Martins, Gabriela; Antunes, Filipe E.; Romano, Anabela; Medronho, Bruno

Lignocellulosic biomass is a renewable and sustainable feedstock, mainly composed of cellulose, hemicellulose, and lignin. Lignin, as the most abundant natural aromatic polymer occurring on Earth, has great potential to produce value-added products. However, the isolation of highly pure lignin from biomass requires the use of efficient methods during lignocellulose fractionation. Therefore, in this work, novel acidic deep eutectic solvents (DESs) were prepared, characterized and screened for lignin extraction from maritime pine wood (Pinus pinaster Ait.) sawdust. The use of cosolvents and the development of new DES were also evaluated regarding their extraction and selectivity performance. The results show that an 1 h extraction process at 175 ?C, using a novel DES composed of lactic acid, tartaric acid and choline chloride, named Lact:Tart:ChCl, in a molar ratio of 4:1:1, allows the recovery of 95 wt% of the total lignin present in pine biomass with a purity of 89 wt%. Such superior extraction of lignin with remarkable purity using a ?green? solvent system makes this process highly appealing for future large-scale applications. ? 2021 Elsevier B.V. All rights reserved.

2021-04Journal article

Restricted access

Gelidium corneum and its solid by-product from agar extraction are sources of high-value and sustainable lipids

Publication . Batista, Joana; Lopes, Diana; Neves, Bruna B.; Pais, Ana Rita; Pinho, Marisa; Moreira, Ana S. P.; Conde, Tiago; Bonciarelli, Stefano; Goracci, Laura; Dias, João; Aguiar, André; Domingues, Pedro; Pereira, Hugo; Domingues, Maria Rosário; Melo, Tânia

The red alga Gelidium corneum is commonly harvested for agar extraction, producing significant biomass residue that remains underutilized. Gelidium corneum and its residue represent promising sources of high-value compounds, including lipid ingredients, encompassing omega-3 and omega-6 polyunsaturated fatty acids, with potential applications in foods and cosmetics. Algae lipids are quite diverse and complex, however the lipidome of G. corneum and its residue, along with their bioactive potential, remain largely unexplored. This study characterized the lipid signatures of G. corneum and its residue after agar extraction using reversed-phase liquid chromatography-tandem mass spectrometry (C18-RP-HPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) for esterified fatty acids (FAs) profiling. Despite low lipid content (<1% dry weight), G. corneum exhibited a higher glycolipid content, while the residue was richer in phospholipids and triacylglycerols. Nine FAs were identified, with FA 20:4 n-6 and FA 20:5 n-3 more abundant in G. corneum, and FA 18:1 n-9 and FA 18:2 n-6 in the residue, highlighting their nutritional and functional values. Their lipid profile comprised more than 400 lipid molecular species, following the trend of more glycolipids in G. corneum and phospholipids in the residue. Complex lipids with bioactive properties were identified in both matrices, expanding our knowledge of the lipid signature of this seaweed. Gelidium corneum lipids showed higher antioxidant scavenging activity and great anti-inflammatory potential by inhibiting cyclooxygenase-2 activity. Although neither matrix inhibited α-amylase, residue lipids effectively inhibited α-glucosidase activity. These findings emphasize G. corneum and its residue as sources of high-value lipids for sustainable biotechnological applications, including foods, nutraceuticals and cosmetics.

2025-11-06Journal article

Open access