Browsing by Author "Serrano, Marisa Isabel Andrade"
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- Determinação estrutural de compostos fenólicos partindo da absorção UV recolhida on-line por HPLC/DADPublication . Amâncio, Débora; Serrano, Marisa Isabel Andrade; Campos, Maria da Graça; Anjos, O.Determinação estrutural de compostos fenólicos partindo da absorção UV recolhida on-line por HPLC/DAD.
- Determination of structural phenolic compounds of Acacia dealbata pollen by HPLC/DADPublication . Anjos, O.; Amâncio, Débora; Serrano, Marisa Isabel Andrade; Campos, Maria da GraçaThere are almost 1 380 species of Acacia found throughout the world. In Portugal the most common Acacia is Acacia dealbata Link and is an invasive species that occupy surrounding area gradually. Several studies were made in order to evaluate some potential uses for these species in order to try delaying their territorial expanding [1]. The aim of this study was to evaluate the source of flavonoids in A. dealbata pollen for use in research of new active molecules using a prior screening by HPLC/DAD. A. dealbata pollen samples were collected directly from the flower stamens and were used for the large scale extraction and isolation of flavonoids [2]. Approximately 10 mg of pollen sample was dried and extracted with 50% ethanol (1:1, v/v) assisted by ultrasonication (30 min), centrifuged at 5000 rpm during 10 min and the supernatant used for HPLC/DAD analysis in a Gilson 170 system with a Waters Spherisorb ODS2 (5 mm) (4.6 × 250 mm) column stabilized at 25 ° C by using an eluent mixture of water-acetonitrile gradient with a flow rate of 0.8 ml/min. The standard chromatograms at 260 and 340nm l [3,4] and spectral data between 220 and 400nm were collected (spectral zone of the phenolic acids and flavonoids in this study). The compounds' structures were determined by UV absorption spectroscopy according to Campos and Markham [4]. The most common flavonoids structures observed in A. dealbata pollen samples were naringenin-chalcone derivatives with different retention times. The other relevant compounds present in A. dealbata pollen were luteolin derivatives (with 6- or 8-O-substitutions), a dihydroflavonol, quercetin derivatives with 3-O-substitutions and a phenolic acid derivative and two unknown compounds (Figure 1). The two compounds not identified will be the focus of the further research. From the data collected it will be done the biological approach in order to validate some bioactivities.
- Identificação de compostos fenólicos e teor de minerais em pólenPublication . Serrano, Marisa Isabel Andrade; Anjos, Ofélia Maria Serralha dos; Campos, Maria da GraçaO pólen corresponde ao material genético masculino das flores que vai ser recolhido pelas abelhas. Este produto é rico em proteínas, aminoácidos livres, hidratos de carbono, lípidos, ácidos gordos, esteróis, vitaminas, minerais e compostos fenólicos, principalmente flavonóides. Com o presente trabalho pretendeu-se analisar pólen de diferentes espécies vegetais, recolhido directamente nos estames e uma amostra de pólen apícola com vista à identificação de compostos fenólicos e polifenólicos. As espécies analisadas foram: Acacia dealbata, Bignonia spp., Carpobrotus edulis, Coleostephus myconis, Crepis spp., Digitalis purpurea, Galactites tomentosus, Lavatera spp., Ligustrum spp., Melaleuca spp., Olea europaea L., Opuntia spp., Papaver rhoeas, Silybum marianum, Tilia spp. e Viburnum tinus. Foi efectuada a acetólise dos diferentes polens para aquisição de imagens e posterior integração na colecção da ESA para identificação. Após a análise microscópica, foram preparados os extractos das espécies vegetais e das cargas polínicas para determinação dos perfis cromatográficos dos compostos fenólicos e flavonóides através de cromatografia líquida com detector de díodos (HPLC/DAD). Verificou-se que cada espécie analisada apresentava um perfil característico e diferente de espécie para espécie, como já tinha sido descrito por outros autores. Os compostos identificados para além de flavonas são essencialmente derivados de ácidos fenólicos maioritariamente derivados do cafeico, heterosidicos da quercetina em C3-O, do canferol, da isoramnetina, da herbacitina e da miricitina com o mesmo padrão de substituição em C3, foram ainda detectados derivados da dihidroflavonol e de naringenina-chalcona. Nas espécies Acacia dealbata e Viburnum tinus foram encontrados compostos ainda não identificados, pelo que serão alvo de estudos posteriores. A análise do pólen apícola revelou a presença dos mesmos compostos encontrados nas amostras de pólen recolhidos directamente dos estames das flores. Foi também feita a análise dos minerais Cádmio, Cobre, Crómio, Chumbo, Ferro, Manganês, Zinco e Níquel por espectrometria de emissão do plasma (ICP-OES) às amostras de pólen anteriormente referidas. Verificou-se que o género Bignonia spp. apresentava elevados valores de todos os minerais em análise em comparação com as restantes amostras. O pólen das espécies estudadas é rico em compostos fenólicos tendo de se continuar este estudo para se ter a caracterização de cada espécie e para identificação de alguns compostos que ainda não estão identificados.
- Therapeutic potential of pollenPublication . Amâncio, Débora; Serrano, Marisa Isabel Andrade; Anjos, O.; Campos, Maria da GraçaThe aim of this study was to evaluate the potential of phenolic compounds of Portuguese flora as a source of flavonoids for use in research of new active molecules using a previous screening by HPLC/DAD. Some of these compounds have bioactive properties as antioxidant and will study in order to determine its anti-inflammatory action. On the other hand, for example, flavones are possible research targets with benzodiazepine-like activity and isoflavones as estrogen-like. When these molecules appear much methylated or hydroxylated, anti-redox potential and antibacterial ability can be assessed. The samples were collected directly into stamens of plants and served as the basis for identification of pollen material collected by bees. The samples analyzed were: Carpobrotus edulis (L.) N.E.Br., Tilia spp., Viburnum tinus L. and Opuntia spp. Approximately 10 mg of pollen sample are dried and extracted with 50% ethanol (1:1, v/v), after was assisted by ultrasonication (30 min), centrifuged at 5000 rpm during 10 min and the supernatant used for HPLC/DAD according Campos and Markham [1]. The compounds structures were determined by UV absorption spectroscopy according Campos and Markham [1]. The more flavonoids common structure in the samples was of 3-O-glycosides of quercetin and kaempferol, and phenolic polymers acids. The less common structure is a derivative of kaempferol that have derivatization at the ring in C6 or C8 alkyl, which makes evident for further evaluation of their therapeutic activity, for the ability to GABAa binding receptors may be one of the possibilities. The studied species present a probability of being able to establish a relationship with greater therapeutic potential (Figure 1).