Browsing by Author "Esteves, Ana P."
Now showing 1 - 8 of 8
Results Per Page
Sort Options
- Antimicrobial activity of Ganoderma lucidum extract, p-hydroxybenzoic and cinnamic acids and their synthetic acetylated glucuronide methyl estersPublication . Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Esteves, Ana P.; Ćirić, Ana; Glamočlija, Jasmina; Martins, Anabela; Soković, Marina; Queiroz, Maria João R.P.Ganoderma lucidumis one of the most famous traditional medicinal mushrooms, being used as functional food and in preventive medicines [1 ]. p-Hydroxybenzoic and cinnamic acids were previously identified, by our research group, in wild G. lucidum from Northeast of Portugal [2].Many studies suggest that phenolic compounds are rapidly metabolized in the human organism being glucuronidation the most prevalent metabolic pathway for phenolic compounds in humans. Despite the large data concerning the antimicrobial effects of phenolic acids [3], studies dealing with the antimicrobial properties of their metabolites or derivatives are scarce due to the fact that most of these compounds are not commercially available. Herein we describe the synthesis of protected (acetylated) glucuronide derivatives of p-hydroxybenzoic and cinnamic acids. Their antimicrobial activity was 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 activity was always higher than the one revealed by the extract. The synthesized acetylated glucuronide derivatives could be deprotected to obtain glucuronide metabolites, which circulate in the human organism as products of the metabolism of the parent compounds.
- Antimicrobial and demelanizing activity of Ganoderma lucidum extract, p-hydroxybenzoic and cinnamic acids and their synthetic acetylated glucuronide methyl estersPublication . 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 activity was always higher than the one revealed by the extract. Nevertheless, the extract was the only one with demelanizing activity against A. niger. The acetylated glucuronide derivatives could be deprotected to obtain glucuronide metabolites, which circulate in the human organism as products of the metabolism of the parent compounds.
- Cytotoxicity of Coprinopsis atramentaria extract, organic acids and their synthesized methylated and glucuronate derivativesPublication . Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Calhelha, Ricardo C.; Esteves, Ana P.; Martins, Anabela; Queiroz, Maria João R.P.Coprinopsis atramentaria is a wild edible mushroom whose methanolic extract revealed a marked antioxidant activity; p-hydroxybenzoic (HA), p-coumaric (CoA) and cinnamic (CA) acids were identified in the extract. In the present work, the cytotoxicity of C. atramentaria extract, previously identified organic acids and their synthesized derivatives (methylated compounds and protected glucuronides) was evaluated. Among all the tested cell lines (MCF-7—breast adenocarcinoma, NCI-H460—non-small cell lung carcinoma, HCT15—colon carcinoma, HeLa—cervical carcinoma and HepG2—hepatocellular carcinoma), the extract presented good activity for the first three cell lines mentioned; in most of the cases methylated and glucuronide derivatives showed a higher activity than the corresponding parental compounds. The substitution of the carboxylic group (in parental organic acids) for an ester (in methylated derivatives) increased the cytotoxicity for tumor cell lines. Acetylated glucuronide derivatives showed higher cytotoxicity when compared with the corresponding parental acids.
- Growth inhibitory activity of Coprinopsis atramentaria extract, phenolic acids and protected acetylated glucuronides on human tumor and non-tumor cell linesPublication . Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Calhelha, Ricardo C.; Martins, Anabela; Esteves, Ana P.; Queiroz, Maria João R.P.Mushrooms represent an important source of compounds with antitumor and immunostimulating properties. Our attention is being focused on the capacity of phenolic acids from mushrooms to miHb1t the growth of different tumor cell lines. Croprinopsis atramentaria (Bull.: Fr.) Redhead, Vilgalys & Moncalvo, is a wild edible mushroom previously characterized by us for its nutritional composition, and also showed a notable antioxidant activity; p-hydroxybenzoic (4.71 mg/100 g dry weight), p -coumaric (0.82 mg/100 g) and cinnamic ( 1.70 mg/100 g) acids were identified in its phenolic extract.PIJ·Icrcin, the growth inhibitory activity on human tumor cell lines (breast- MCF-7, non-small cell lung- NCI-H460, colon- HCT- 15, hepatocellular- HepG2 and cervical HeLa) and non-tumor porcine liver primary cell culture (PLP2), was evaluated by sulforhodamine B assay, using C. atramentaria extract, phenolic acids, cinnamic acid and their protected glucuronides (HAGP, CoAGP and CAGP; Scheme) obtained reacting phydroxybenzoic (HA), p-coumaric (CoA) and cinnamic (CA) acids, respectively, with acetobromo-a-0-glucuronic acid methyl ester
- Patente Nacional nº 107646 - Método de obtenção do éster metílico do ácido acetobromo Α-D-GlucurónicoPublication . Queiroz, Maria João R.P.; Esteves, Ana P.; Martins, Anabela; Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Sousa, Marco Alexandre Gomes da Silva Pires deA presente invenção consiste num novo método para a produção do éster metílico do ácido acetobromo Α-D-glucurónico. Com este método, obtém-se um rendimento global de 42%. O processo consiste na produção do intermediário éster Metílico-Β-d-tetra-o-acetilado do ácido glucurónico com um rendimento de 64% e, fazendo reagir este produto com anidrido acético na presença de ácido perclórico, Fósforo vermelho, bromo, entre outros reagentes, é possível obter o composto alvo éster metílico do ácido acetobromo Α-d-glucurónico, na forma de um sólidobranco e cristalino, à escala de gramas. As vantagens deste novo método estão principalmente relacionadas com segurança, maior facilidade de execução, rapidez e redução significativa dos custos de produção.
- Phenolic acids in the wild mushroom Ganoderma lucidum and synthesis of some possible metabolites.Publication . Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Martins, Anabela; Esteves, Ana P.; Queiroz, Maria João R.P.Ganoderma lucidum is one of the most extensive!) studied mushrooms due to its medicinal properties, p-Hydroxybenzoic acid was the most abundant phenolic acid found in this mushroom. after HPLC-DAD-MS analysis. In the present work we describe the synthesis of glucuronide and methyl derivatives of p-hydroxybenzoic acid, which arc two of the main circulating metabolites found in humans. Their biological activity is going to be evaluated and compared to the parent compound in order to understand the in vivo mechanism of action of phenolic acids, considering their metabolism
- Synthesis of acetylated glucuronide derivatives of p-hydroxybenzoic and cinnamic acids, two compounds commonly found in wild mushroomsPublication . Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Martins, Anabela; Esteves, Ana P.; Queiroz, Maria João R.P.Dietary phenolic compounds are widely considered to contribute to health benefits in humans. However, little is known about their bioactive forms in vivo and the mechanisms by which they may contribute toward disease prevention. Moreover, many studies on the biological effects of phenolic compounds have ignored the question of their achievable concentrations in the circulation after ingestion as well as their metabolism [1]. Wild mushrooms are extensively studied due to their medicinal properties which have been related to the presence of bioactive molecules such as phenolic compounds. p-Hydroxibenzoic acid is among the most abundant phenolic acids found in wild mushrooms, as well as cinnamic acid [2]. The present work aims at contributing to the knowledge of the mechanisms involved in the healthpromoting properties of phenolic acids and precursors, usually present in mushrooms. Herein, we describe the synthesis of acetylated glucuronide derivatives of p-hydroxybenzoic and cinnamic acids, as protected glucuronide metabolites (Scheme).
- The probative value of municipal documents in the exchange of present goods for future goodsPublication . Crisóstomo, André; Esteves, Ana P.; Nogueira, Sónia P.Utilizado com muita frequência em épocas de crescimento do mercado imobiliário, o contrato de permuta de bens presentes por bens futuros, é visto na ordem jurídica portuguesa como um negócio com incoerências ao nível da sua aceitação do ponto de vista substantivo. Ao passo que se trata de uma troca de uma coisa presente por uma coisa futura, uma das partes fica impedida de realizar a sua prestação e, ao mesmo tempo, colide com a licitude, determinabilidade e existência que as coisas que são objeto dos contratos em geral devem ter. Neste sentido, o estudo pretendeu avançar com uma (ainda que, hipotética), solução uniforme para as incoerências suscitadas, através do binómio Autarquias Locais – Direito, em concreto, de que forma os documentos administrativos condicionam e influenciam a produção de efeitos reais e obrigacionais dos negócios privados. A investigação seguiu uma metodologia qualitativa e a recolha de informação assentou em entrevistas semiestruturadas realizadas nas Câmaras Municipais de Bragança, Mirandela, Chaves e Vila Real, que em complemento com a (pouca) pesquisa bibliográfica, foi possível concluir que, em particular, o pedido de informação prévia submetido na respetiva Câmara Municipal, por quem não seja o proprietário do prédio, que se pronuncie favoravelmente sobre a viabilidade da constituição do regime da propriedade horizontal com a aprovação simultânea da planta de arquitetura do edifício, é o documento idóneo para resolver as dúvidas suscitadas, através do qual é formulado o registo provisório por natureza a favor do futuro adquirente, até à conclusão da construção do edifício.