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Biblioteca Digital do IPB (53.442 recursos)

A Biblioteca Digital do IPB, tem por objectivo divulgar e permitir o livre acesso à produção científica produzida pela comunidade académica, promovendo a integração, partilha e a visibilidade da informação científica e garantindo a preservação da memória intelectual do Instituto Politécnico de Bragança.

BB - Artigos em Revistas Indexadas ao ISI

Mostrando recursos 1 - 20 de 247

  1. Chemical characterization of Ginkgo biloba L. and antioxidant properties of its extracts and dietary supplements

    Pereira, Eliana; Barros, Lillian; Ferreira, Isabel C.F.R.
    Ginkgo biloba L. is the most commercialized medicinal plant worldwide, being its consumption related to prevention, and even decrease of the progression of degenerative neurological diseases. Considering the correlation between oxidative stress and the mentioned diseases, the antioxidant activity of different dietary supplements (syrup and several pills) was evaluated and compared to the leaves infusion, aqueous and methanolic extracts. Furthermore, G. biloba was chemically characterized in nutritional and bioactive components namely, fatty acids, sugars, organic acids, tocopherols, phenolics and flavonoids. Palmitic, α-linolenic and oleic acids were the main fatty acids found; fructose was the most abundant sugar; quinic acid was...

  2. Importance of local knowledge in plant resources management and conservation in two protected areas from Trás-os-Montes, Portugal

    Carvalho, Ana Maria; Frazão-Moreira, Amélia
    Departamento Antropologia da Faculdade Ciências Sociais e Humanas da Universidade Nova de Lisboa, CRIA – Centro em Rede de Investigação em Antropologia, CIMO – Centro de Investigação de Montanha, ICNB/PNM, ESAB/IPB

  3. Arnica: a multivariate analysis of the botany and ethnopharmacology of a medicinal plant complex in the Iberian Peninsula and the Balearic Islands

    Obón, Concepcion; Rivera, Diego; Alonso, Verde; Fajardo, José; Valdés, Arturo; Alcaraz, Francisco; Carvalho, Ana Maria
    Ethnopharmacological relevance Medicinal plant complexes of different species sharing vernacular names, morphological and aromatic characteristics and uses are common in traditional medicine of different cultures. A quantitative methodology as a tool for ethnopharmacological studies is presented for systematically analyzing morphological and therapeutic features shared by several species integrating such complexes. Aim of the study The aim of this paper is to apply a novel methodology to determine whether complexes are homogeneous and species within the complexes are completely interchangeable or not. Moreover, to find out if those species giving the name to the complex are also those which provide a large number of...

  4. Antimicrobial activity, growth inhibition of human tumor cell lines and phytochemical characterization of the hydromethanolic extract obtained from Sapindus saponaria L. aerial parts.

    Rashed, Khaled N.; Ćirić, Ana; Glamočlija, Jasmina; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Soković, Marina
    Thehydromethanolic extract of Sapindus saponaria L. aerial parts was investigated for antimicrobial activity (against several Grampositive and Gram-negative bacteria and fungi) and capacity to inhibit the growth of different human tumor cell lines as also nontumor liver cells. The evaluated extract was further characterized in terms of phytochemicals using UV, 1H-NMR, 13C-NMR, and MS spectroscopic tools. The extract has shown a significant antimicrobial activity on all tested bacterial and fungal species. The best activity was achieved against Bacillus cereus and Staphylococcus aureus among bacteria and against all three Penicillium species tested. It also revealed cytotoxicity against human colon (HCT-15), cervical (HeLa),...

  5. Bioactivity and chemical characterization in hydrophilic and lipophilic compounds of Chenopodium ambrosioides L.

    Barros, Lillian; Pereira, Eliana; Calhelha, Ricardo C.; Dueñas, Montserrat; Carvalho, Ana Maria; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.
    The bioactive properties (antioxidant and antitumour activities, and hepatotoxicity) of the infusion and methanolic extracts of Chenopodium ambrosioides L., a plant commonly used in Portuguese folk medicine, were compared. The chemical composition in hydrophilic (sugars, organic acids and phenolic compounds) and lipophilic (fatty acids and tocopherols) fractions were determined. In general, the infusion revealed higher antioxidant activity, while the methanolic extract was the only one showing antitumour effects against colon, cervical and hepatocellular carcinoma cell lines. No toxicity in non-tumour cells was observed either for the infusion or the extract. The studied plant proved to be a good source of...

  6. New di(hetero)arylethers and di(hetero)arylamines in the thieno[3,2-b]pyridine series: Synthesis, growth inhibitory activity on human tumor cell lines and non-tumor cells, effects on cell cycle and on programmed cell death

    Queiroz, Maria João R.P.; Peixoto, Daniela; Calhelha, Ricardo C.; Soares, Pedro; Santos, Tiago; Lima, Raquel T.; Campos, Joana F.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Vasconcelos, M. Helena
    New fluorinated and methoxylated di(hetero)arylethers and di(hetero)arylamines were prepared functionalizing the 7-position of the thieno[3,2-b]pyridine, using copper (C–O) or palladium (C–N) catalyzed couplings, respectively, of the 7-bromothieno[3,2-b]pyridine, also prepared, with ortho, meta and para fluoro or methoxy phenols and anilines. The compounds obtained were evaluated for their growth inhibitory activity on the human tumor cell lines MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), HCT15 (colon carcinoma), HepG2 (hepatocellular carcinoma) and HeLa (cervical carcinoma). The most active compounds, a di(hetero)arylether with a methoxy group in the meta position relative to the ether function and two di(hetero)arylamines with a methoxy group...

  7. Use of UFLC-PDA for the analysis of organic acids in thirty-five species of food and medicinal plants

    Pereira, Carla; Barros, Lillian; Carvalho, Ana; Ferreira, Isabel C.F.R.
    Analysis of organic acids has become increasingly important due to their role in the physiological activity of plants, and many separation methods have been developed for the simultaneous determination of these compounds in plant samples. Herein, ultra fast liquid chromatography and photodiode array detection (UFLC-PDA) was applied to the analysis of organic acids in young shoots, leaves, aerial parts and flowering shoots, as well as in flowers and fruits, of thirty five plant species, according to their traditional use. The studied plants were divided in three groups: traditionally cultivated food plants, wild edible plants and wild medicinal plants. Most of the...

  8. The role of phenolic compounds in the fight against cancer – a review

    Carocho, Márcio; Ferreira, Isabel C.F.R.
    Cancer is a worldwide scourge; it’s the leading cause of death in developed countries and is increasing in developing countries. Mankind has been trying with effort to find better and cheaper treatments with fewer side effects, to reduce the incidence of the disease and its consequent mortality. For many years, phenolic compounds have been intensely studied for their antitumor, proapoptotic and antiangiogenic effects. In recent years, the usage of these compounds has increased considerably. This manuscript intends to structurally characterize the different phenolic compounds (flavonoids, hydroxycinnamates, hydroxybenzoates, coumarins, xanthones, chalcones, stilbenes, lignins and lignans) and their metabolic pathways as well...

  9. Comparative study of phytochemicals and antioxidant potential of wild edible mushroom caps and stipes

    Ribeiro, Bárbara; Lopes, Rosário; Andrade, P.B.; Seabra, R.M.; Gonçalves, Rui; Baptista, Paula; Quelhas, Inês; Valentão, P.
    A comparative study of the organic acids and phenolics composition and of the total alkaloids content of entire wild edible mushrooms (Russula cyanoxantha, Amanita rubescens, Suillus granulatus and Boletus edulis) and correspondent caps and stipes was performed. All species presented oxalic, citric, malic and fumaric acids, with A. rubescens exhibiting the highest total organic acids content. Organic acids were preferably fixed in the cap. Among phenolics, only p-hydroxybenzoic acid was found in A. rubescens and S. granulatus, in very low amounts. B. edulis was the species that presented the highest total alkaloid amounts. Except for this species, alkaloids mainly accumulated in the cap. All of...

  10. Effects of different processing technologies on chemical and antioxidant parameters of Macrolepiota procera wild mushroom

    Fernandes, Ângela; Barros, Lillian; Barreira, João C.M.; Antonio, Amilcar L.; Oliveira, M.B.P.P.; Martins, Anabela; Ferreira, Isabel C.F.R.
    Mushrooms are very perishable foods, demanding for processing technologies that retain chemical and nutritional characteristics of fresh forms. In this work, the influence of freezing, drying and gamma irradiation on chemical parameters and antioxidant potential of Macrolepiota procera was assessed through one-way ANOVA complemented with principal component analysis. Proximate composition was evaluated by AOAC procedures, while fatty acids, tocopherols and free sugars were determined using chromatographic techniques. Antioxidant activity was measured using in vitro assays. M. procera samples have low energetic values, with moisture and carbohydrates as major nutrients. Linoleic, palmitic and oleic acids were the major fatty acids; δ-tocopherol...

  11. Chemical composition of wild and commercial Achillea millefolium L. and bioactivity of the methanolic extract, infusion and decoction

    Dias, Maria Inês; Barros, Lillian; Dueñas, Montserrat; Pereira, Eliana; Carvalho, Ana Maria; Alves, Rita C.; Oliveira, M.B.P.P.; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.
    Medicinal plants used in folk medicine are being increasingly studied and used on pharmaceutical, food and nutraceutical fields. Herein, wild and commercial samples of Achillea millefolium L. (yarrow) were chemically characterized with respect to their macronutrients, free sugars, organic acids, fatty acids and tocopherols. Furthermore, in vitro antioxidant properties (free radicals scavenging activity, reducing power and lipid peroxidation inhibition) and antitumour potential (against breast, lung, cervical and hepatocellular carcinoma cell lines) of their methanolic extract, infusion and decoction (the most consumed forms) was evaluated and compared to the corresponding phenolic profile obtained by high performance liquid chromatography and mass spectrometry....

  12. Antimicrobial activity of phenolic compounds identified in wild mushrooms, SAR analysis and docking studies

    Alves, Maria José; Ferreira, Isabel C.F.R.; Froufe, Hugo J.C.; Abreu, Rui M.V.; Martins, Anabela; Pintado, Manuela
    Aim and Methods: Although the antimicrobial activity of extracts from several mushroom species have been reported, studies with the individual compounds present in that extracts are scarce. Herein, the antimicrobial activity of different phenolic compounds identified and quantified in mushroom species from all over the world was evaluated. Furthermore, a structure activity relationship (SAR) analysis and molecular docking studies were performed, in order to provide insights in the mechanism of action of potential antimicrobial drugs for resistant microorganisms. Results: 2,4-Dihydroxybenzoic and protocatechuic acids were the phenolic compounds with higher activity against the majority of Gram negative and Gram positive bacteria....

  13. Characterisation of phenolic compounds in wild fruits from Northeastern Portugal

    Guimarães, Rafaela; Barros, Lillian; Dueñas, Montserrat; Carvalho, Ana Maria; Queiroz, Maria João R.P.; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.
    This study aimed to analyse the phenolic composition of wild fruits of Arbutus unedo (strawberry-tree), Prunus spinosa (blackthorn), Rosa canina and Rosa micrantha (wild roses). Analyses were performed by HPLC-DAD-ESI/MS. Prunus spinosa fruits presented the highest concentration in phenolic acids (29.78 mg/100 g dry weight), being 3-O-caffeoylquinic acid the most abundant one, and flavone/ols (57.48 mg/100 g), among which quercetin3-O-rutinoside (15.63 mg/100 g) was the majority compound. (+)-Catechin was the most abundant compound in A. unedo (13.51 mg/100 g) and R. canina (3.59 mg/100 g) fruits. Arbutus unedo fruits presented the highest concentration in flavan-3-ols (36.30 mg/100 g). Cyanidin 3-O-glucoside...

  14. 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR-2 tyrosine kinase inhibitors: Synthesis, biological evaluation, and molecular modelling studies

    Soares, Pedro; Costa, Raquel; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Peixoto, Daniela; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Soares, Raquel; Queiroz, Maria João R.P.
    The Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) is a tyrosine kinase receptor involved in the growth and differentiation of endothelial cells that is implicated in tumor-associated angiogenesis. In this study novel 1-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas were synthesized and evaluated for the VEGFR-2 tyrosine kinase inhibition. Three of these compounds showed good VEGFR-2 inhibition presenting low IC50 values (150-199 nM) in enzymatic assays. The latter promoted also significant inhibition of cell proliferation at low concentrations (0.5-1 µM), not affecting cell viability, of VEGF-stimulated Human Umbilical Vein Endothelial Cells (HUVECs) using the BrdU assay. The determination of the total and phosphorylated (active) VEGFR-2 was performed...

  15. Nutrients and non-nutrients composition and bioactivity of wild and cultivated Coprinus comatus (O.F.Müll.) Pers.

    Stojković, Dejan; Reis, Filipa S.; Barros, Lillian; Glamočlija, Jasmina; Ćirić, Ana; Van Griensven, Leo J.L.D.; Soković, Marina; Ferreira, Isabel C.F.R.
    Mushrooms have been reported as sources of biomolecules with various potential. Coprinus comatus was studied to obtain information about this species, comparing cultivated and wild samples. Free sugars, fatty acids, tocopherols, organic acids and phenolic acids were analysed by chromatographic techniques coupled to different detectors. C. comatus methanolic extractwas tested for its antioxidant potential (reducing power, radical scavenging activity and lipid peroxidation inhibition) and antimicrobial properties (tested towards Gram positive and negative bacteria, and microfungi). The toxicity for liver cells was tested in porcine liver primary cells. Both studied samples revealed similar nutritional value and energy contribution. The cultivated sample...

  16. Study of chemical changes and antioxidant activity variation induced by gamma-irradiation on wild mushrooms: comparative study through principal component analysis

    Fernandes, Ângela; Barreira, João C.M.; Antonio, Amilcar L.; Santos, Pedro M.P.; Martins, Anabela; Oliveira, M.B.P.P.; Ferreira, Isabel C.F.R.
    Mushrooms are especially sensitive to senescence, browning, water loss and microbial attack. Furthermore, wild species are characterized for their seasonality, demanding the development of suitable preservation technology. Gamma-irradiation was previously tested in wild Lactarius deliciosus, being verified that its application up to 1 kGy did not imply significant changes in chemical parameters. Herein, the effects of higher gamma-irradiation doses, typically used in natural food matrices like fruits or vegetables, were assessed in Boletus edulis Bull.: Fr. and Hydnum repandum L.: Fr. by checking for changes in nutritional parameters, free sugars, tocopherols, fatty acids, organic acids and antioxidant activity indicators. To...

  17. Suillus luteus methanolic extract inhibits cell growth and proliferation of a colon cancer cell line

    Santos, Tiago; Tavares, Catarina; Sousa, Diana; Vaz, Josiana A.; Calhelha, Ricardo C.; Martins, Anabela; Almeida, Gabriela M.; Ferreira, Isabel C.F.R.; Vasconcelos, M. Helena
    Several edible mushrooms extracts are known to have tumour cell growth inhibitory potential. The objective of this work was to study this potential in extracts of Suillus luteus collected from the Northeast of Portugal. Various extracts were prepared and their effect on tumour cell growth was studied with the SRB assay in four human tumour cell lines: MCF-7 (breast), NCI-H460 (non-small cell lung cancer), AGS (gastric) and HCT-15 (colon). The methanolic extract of S. luteus was the most potent extract. This extract was slightly more potent in the HCT-15 cells (with mutant p53, GI50=17.8 ± 1.6 µg/mL) than in the...

  18. Bryonia dioica, Tamus communis and Lonicera periclymenum fruits: characterization in phenolic compounds and incorporation of their extracts in hydrogel formulations for topical application

    Barreira, João C.M.; Pereira, Eliana; Dueñas, Montserrat; Carvalho, Ana Maria; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.
    Plants are being increasingly used in dermatological formulations, since their collateral effects are lower than those caused by synthetic products. Hydrogels represent efficient formulations to incorporate plant extracts, providing good percutaneous absorption, non-greasy texture and easy application. Bryonia dioica Jacq. (white-bryony), Tamus communis L. (black-bryony) and Lonicera periclymenum L. (honeysuckle) fruits have important applications as topical homemade remedies. The phenolic extracts of B. dioica, T. communis and L. periclymenum were characterized by HPLC-DAD-ESI/MS, and further incorporated into hydrosoluble gels in order to evaluate their antioxidant potential. The hydrogels were prepared with each fruit extract at the EC50 value (obtained herein...

  19. Antioxidant properties, anti-hepatocellular carcinoma activity and hepatotoxicity of artichoke, milk thistle and borututu

    Pereira, Carla; Calhelha, Ricardo C.; Barros, Lillian; Ferreira, Isabel C.F.R.
    Cynara scolymus (artichoke), Silybum marianum (milk thistle) and Cochlospermum angolensis (borututu) are three plants widely used regarding hepatoprotective effects but to the best of our knowledge no anti-hepatocellular carcinoma activity has been studied in the most consumed forms: infusions and dietary supplements. Herein, antioxidant properties, anti-hepatocellular carcinoma activity and toxicity of infusions and dietary supplements of the mentioned plants were evaluated and compared. All the samples revealed antioxidant properties with EC50 values lower than the daily recommended dose, but infusions showed higher biological activity than dietary supplements. Borututu infusion gave the highest antioxidant activity (EC50≤170 µg/mL), and also revealed anti-hepatocellular...

  20. Antimicrobial and demelanizing activity of Ganoderma lucidum extract, p-hydroxybenzoic and cinnamic acids and their synthetic acetylated glucuronide methyl esters

    Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Esteves, Ana P.; Ćirić, Ana; Glamočlija, Jasmina; Martins, Anabela; Soković, Marina; Queiroz, Maria João R.P.
    Mushroom extracts or isolated compounds may be useful in the search of new potent antimicrobial agents. Herein, it is described the synthesis of protected (acetylated) glucuronide derivatives of p-hydroxybenzoic and cinnamic acids, two compounds identified in the medicinal mushroom Ganoderma lucidum. Their antimicrobial and demelanizing activities were evaluated and compared to the parent acids and G. lucidum extract. p-Hydroxybenzoic and cinnamic acids, as also their protected glucuronide derivatives revealed high antimicrobial (antibacterial and antifungal) activity, even better than the one showed by commercial standards. Despite the variation in the order of parent acids and the protected glucuronide derivatives, their antimicrobial...

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