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Seaweeds as preventive agents for cardiovascular diseases: from nutrients to functional foods

Publication . Cardoso, Susana M.; Pereira, Olívia R.; Seca, Ana M.L.; Pinto, Diana; Silva, Artur

Being naturally enriched in key nutrients and in various health-promoting compounds, seaweeds represent promising candidates for the design of functional foods. Soluble dietary fibers, peptides, phlorotannins, lipids and minerals are macroalgae’s major compounds that can hold potential in high-value food products derived from macroalgae, including those directed to the cardiovascular-health promotion. This manuscript revises available reported data focusing the role of diet supplementation of macroalgae, or extracts enriched in bioactive compounds from macroalgae origin, in targeting modifiable markers of cardiovascular diseases (CVDs), like dyslipidemia, oxidative stress, vascular inflammation, hypertension, hypercoagulability and activation of the sympathetic and renin-angiotensin systems, among others. At last, the review also describes several products that have been formulated with the use of whole macroalgae or extracts, along with their claimed cardiovascular-associated benefits.

2015Journal article

Open access

Probing the interactions between ionic liquids and water: experimental and quantum chemical approach

Publication . Khan, Imran; Kurnia, Kiki A.; Mutelet, Fabrice; Pinho, Simão; Coutinho, João A.P.

For an adequate choice or design of ionic liquids, the knowledge of their interaction with other solutes and solvents is an essential feature for predicting the reactivity and selectivity of systems involving these compounds. In this work, the activity coefficient of water in several imidazolium-based ionic liquids with the common cation 1-butyl-3-methylimidazolium was measured at 298.2 K. To contribute to a deeper insight into the interaction between ionic liquids and water, COSMO-RS was used to predict the activity coefficient of water in the studied ionic liquids along with the excess enthalpies. The results showed good agreement between experimental and predicted activity coefficient of water in ionic liquids and that the interaction of water and ionic liquids was strongly influenced by the hydrogen bonding of the anion with water. Accordingly, the intensity of interaction of the anions with water can be ranked as the following: [CF3SO3](-) < [SCN](-) < [TFA](-) < Br(-) < [TOS](-) < Cl(-) < [CH3SO3](-) [DMP](-) < [Ac](-). In addition, fluorination and aromatization of anions are shown to reduce their interaction with water. The effect of temperature on the activity coefficient of water at infinite dilution was measured by inverse gas chromatography and predicted by COSMO-RS. Further analysis based on COSMO-RS provided information on the nature of hydrogen bonding between water and anion as well as the possibility of anion-water complex formation.

2014Journal article

Restricted access

Caracterização reológica de amostras de comerciais de mel de urze

Publication . Martins, Vitor Manuel Ramalheira; Caveiro, Elsa; Falcão, Soraia; Vilas-Boas, Miguel

O mel de urze (Erica sp.) português é um produto apícola característico das regiões montanhosas, cuja composição química tem sido objeto de diversos estudos [1,2]. Este mel é bastante apreciado pelo consumidor devido a algumas das suas propriedades sensoriais, como por exemplo a textura, que é influenciada pelas características reológicas do mel.

2018Conference object

Open access

Characterization of 2,3-diarylxanthones by electrospray mass spectrometry: gas-phase chemistry versus known antioxidant activity properties

Publication . Silva, Eduarda M.P.; Barros, Cristina M.R.F.; Santos, Clementina M.M.; Barros, António S.; Domingues, Maria R.M.; Silva, Artur

Xanthones (XH) are a class of heterocyclic compounds widely distributed in nature that hold numerous noteworthy biological and antioxidant activities. Therefore, it is of utmost importance to achieve relevant detailed structural information to understand and assist prediction of their biological properties. The potential relationship between radical-mediated xanthone chemistry in the gas phase and their promising antioxidant activities has not been previously explored.

2016Journal article

Open access

(E)-2-(4-Arylbut-1-en-3-yn-1-yl)chromones as synthons for the synthesis of xanthone-1,2,3-triazole dyads

Publication . Albuquerque, Hélio; Santos, Clementina M.M.; Cavaleiro, José; Silva, Artur

Xanthone-1,2,3-triazole dyads have been synthesized by two different approaches, both starting from novel (E)-2-(4-arylbut-1-en-3-yn-1-yl)chromones, prepared through a base-catalyzed aldol reaction of 2-methylchromone and arylpropargyl aldehydes. In the first method, the xanthone moiety is built by Diels-Alder reaction of the referred unsaturated chromones with N-methylmaleimide under microwave irradiation, followed by oxidation of the obtained adducts with DDQ, whereas the 1,2,3-triazole ring results from the cycloaddition reaction of the acetylene moiety with sodium azide. The second strategy first involves the cycloaddition reaction with sodium azide to provide the 1,2,3-triazole ring, followed by methylation of the triazole NH group prior to Diels-Alder reaction with N-methylmaleimide. The last step in this synthesis of novel xanthone-1,2,3-triazole dyads entails oxidation of the cycloadducts with DDQ.

2015Journal article

Open access