Investigação Química da Marthasterias Glacialis da Costa Portuguesa, como Fonte de Compostos com Actividade Farmacêutica

Marine organisms are increasingly regarded as a promising source of bioactive molecules for human pharmacotherapy, being used in conditions such as cancer, inflammation, infection and pain.Marthasterias glacialis, also known as the spiny sea-star, is an echinoderm common in the Portuguese coast, however little information is available regarding its chemical constituents.In this work, the chemistry of this organism is reviewed taking into account the latest reports on several classes of natural products, namely carotenoids, sterols, fatty acids and amino acids.Os organismos marinhos tem sido considerados como uma fonte promissora de moléculas com actividade farmacoterapêutica para os humanos, sendo utilizadas em distintas patologias como neoplásicas, inflamatórias, infecciosas ou álgicas. A Marthasterias glacialis, também conhecida como estrela do mar espinhosa, é um equinodermo muito comum na costa portuguesa, existindo, contudo, pouca informação sobre a sua composição quimica.Pretende-se rever a quimica deste organismo tendo em conta os ultimos dados sobre as diferentes classes de produtos, nomeadamente carotenoides, esteróides, ácidos gordos e aminoácidos

Metabolic profiling and biological capacity of Pieris brassicae fed with kale (Brassica oleracea L. Var. Acephala).

Vegetables of the Brassica group are the most commonly grown and consumed worldwide. Food plants with apparent cancer and cardiovascular di sease-preventing properties include several varieties of Brassica oleraceae. The majority of the herbivorous insect species are specialized feeders, for which the behavioral decision to accept a plant as food or oviposition substrate is mainly related with sensory information. Pieris insects (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants

Composição química e actividade antioxidante das folhas internas da couve tronchuda

A couve tronchuda (Brassica oleracea L. var. costata DC) é uma das couves mais consumidas pelos portugueses, especialmente durante o Inverno, apresentando as folhas (internas e externas) diferenças organolépticas marcadas. No presente trabalho procedeu-se à caracterização química das folhas internas de couve tronchuda, através da identificação e quantificação dos compostos fenólicos e dos ácidos orgânicos que as compõem e avaliou-se o seu potencial antioxidante. Foram identificados e quantificados, por HPLC-DAD-ESI-MS e HPLC/DAD, respectivamente, 17 compostos fenólicos: quercetina 3-O-soforósido-7-O-glucósido, ácido 3-p-cumaroilquínico, campferol 3-O-soforósido-7-O-glucósido, campferol 3-O-(cafeoil)-soforósido-7-O-glucósido, ácido sinapoilglucósido, campferol 3-O-(sinapoil)-soforósido-7-O-glucósido, campferol 3-O-(feruloil)-soforósido-7-O-glucósido, campferol 3-O-(p-cumaroil)-soforósido-7-O-glucósido, ácido 4-p-cumaroilquínico, ácido sinápico, campferol 3-O-soforósido, 3 isómeros de 1,2-di-sinapoilgentiobiose, 1-sinapoil-2-feruloilgentiobiose, 1,2,2-tri-sinapoilgentiobiose e 1,2’-di-sinapoil-2-feruloilgentiobiose. Foram também identificados e quantificados, por HPLC/UV, sete ácidos orgânicos (ácidos aconítico, cítrico, ascórbico, málico, quínico, chiquímico e fumárico). A actividade antioxidante do extracto aquoso foi aferida pela capacidade para interceptar o radical DPPH e espécies reactivas de oxigénio (radicais superóxido e hidroxilo e ácido hipocloroso), tendo revelado grande efeito protector

Tronchuda cabbage flavonoids uptake by Pieris brassicae

The flavonoid pattern of larvae of cabbage white butterfly (Pieris brassicae L.; Lepidoptera: Pieridae) reared on the leaves of tronchuda cabbage was analysed by HPLC-DAD-MS/MS-ESI. Twenty flavonoids were identified or characterised, namely 16 kaempferol and four quercetin derivatives. Kaempferol 3-O-sophoroside, a minor component of tronchuda cabbage, was found to be the main component in P. brassicae (15.8%). Apart from this, only two other flavonoids present in significant amounts in tronchuda cabbage (kaempferol 3-O-sophoroside-7-O-glucoside and kaempferol 3-O-sophoroside-7-O-sophoroside) were found in the larvae. The larvae have high amounts of quercetin derivatives (18.5%), which were present only in trace amounts in tronchuda cabbage extracts, suggesting that P. brassicae is able to selectively sequester these flavonoids. The occurrence of a high content of flavonoids not detectable in tronchuda cabbage extracts indicates that P. brassicae larvae are able to metabolize dietary flavonoids

Induction of phenolic compounds in Hypericum perforatum L. cells by colletotrichum gloeosporioides elicitation

Changes in phenolic metabolism after elicitation with Colletotrichum gloeosporioides (CG) has been studied in Hypericum perforatum L. (HP) cell suspension cultures. Soluble phenolics were analysed by HPLC–DAD and HPLC–DAD–MS/MS. HP cultures elicited with the CG elicitor showed a significant increase in xanthone accumulation. Xanthone accumulation increased twelve fold when the cells were primed with methyl-jasmonate (MeJ) or salicylic acid (SA), before elicitation. HP cultures exposed only to MeJ produced a set of flavonoids, the flavones which represent a substantial part (approx. 40%) of the total flavonoids accumulated in these cells. The possible importance of xanthones as a component of defence mechanism of HP against biotic stress is discussed.Fundação para a Ciência e a Tecnologia (FCT

Chemical composition and antioxidant activity of tronchuda cabbage internal leaves

A phytochemical study was undertaken on the internal leaves of tronchuda cabbage (Brassica oleracea L. var. costata DC). Seventeen phenolic compounds were characterized and quantified by reversed-phase HPLCDAD-ESI-MSn and HPLC/DAD, respectively: quercetin 3-O-sophoroside-7-O-glucoside, 3-p-coumaroylquinic acid, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(caffeoyl)-sophoroside-7-O-glucoside, sinapoyl glucoside acid, kaempferol 3-O-(sinapoyl)-sophoroside-7-Oglucoside, kaempferol 3-O-(feruloyl)-sophoroside-7-Oglucoside, kaempferol 3-O-(p-coumaroyl)-sophoroside- 7-O-glucoside, 4-p-coumaroylquinic acid, sinapic acid, kaempferol 3-O-sophoroside, 3 isomeric forms of 1,2- disinapoylgentiobiose, 1-sinapoyl-2-feruloylgentiobiose, 1,2,2-trisinapoylgentiobiose and 1,2'-disinapoyl-2-feruloylgentiobiose. Seven organic acids (aconitic, citric, ascorbic, malic, quinic, shikimic and fumaric acids) were also identified and quantified. The hot water extract of tronchuda cabbage internal leaves was investigated for its capacity to act as a scavenger of DPPH- radical and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid), exhibiting antioxidant capacity in a concentration dependent manner against all radicals.Tronchuda cabbage internal leave

Antioxidative properties of tronchuda cabbage (Brassica oleracea L. var. costata DC) external leaves against DPPH, superoxide radical, hydroxyl radical and hypochlorous acid

The ability of the aqueous extract of tronchuda cabbage (Brassica oleracea L. var. costata DC) external leaves to act as a scavenger of DPPH- and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid) was investigated. A phytochemical study was also undertaken, and thirteen phenolic compounds and five organic acids were identified and quantified. Tronchuda cabbage extracts exhibited antioxidant capacity in a concentration-dependent manner in all assays, although some pro-oxidant effect was also noticed. The samples with higher phenolic and organic acid contents displayed the major antioxidant potentials

Analysis and quantification of flavonoidic compounds from Portuguese olive (Olea europeae L.) leaf cultivars

Twenty three samples of 18 Portuguese olive leaf cultivars were analysed by a reversed-phase HPLC/DAD procedure and eight flavonoidic compounds were identified and quantified (luteolin 7,40-O-diglucoside, luteolin 7-O-glucoside, rutin, apigenin 7-O-rutinoside, luteolin 40-O-glucoside, luteolin, apigenin and diosmetin). Luteolin 7,40-O-diglucoside and luteolin 40-O-glucoside were identified by HPLC/DAD/MS/MS – ESI. The studied olive leaf samples showed a common phenolic pattern, in which luteolin 40-O-glucoside was almost always the major compoun

Walnut (Juglans regia L.) leaves: phenolic compounds, antimicrobial activity ans antioxidant potential of different cultivars

Different cultivars of walnut (Juglans regia L.) leaves (Cv. Lara, Franquette, Mayette, Marbot, Mellanaise and Parisienne) grown in Portugal, were investigated in what concerns phenolic compounds and antimicrobial and antioxidant properties. Phenolics analysis was performed by reversed-phase HPLC/DAD and 10 compounds were identified and quantified: 3- and 5-caffeoylquinic acids, 3- and 4-pcoumaroylquinic acids, p-coumaric acid, quercetin 3-galactoside, quercetin 3-pentoside derivative, quercetin 3-arabinoside, quercetin 3-xyloside and quercetin 3-rhamnoside. The antimicrobial capacity was screened against Gram positive (Bacillus cereus, B. subtilis, Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans). Walnut leaves selectively inhibited the growth of Gram positive bacteria, being B. cereus the most susceptible one (MIC 0.1 mg/mL). Gram negative bacteria and fungi were resistant to the extracts at 100 mg/mL. Lara walnut leaves were also submitted to antibacterial assays using 18 clinical isolates of Staphylococcus sp. Antioxidant activity was accessed by the reducing power assay, the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and b-carotene linoleate model system. In a general way, all of the studied walnut leaves cultivars presented high antioxidant activity (EC50 values lower than 1 mg/mL), being Cv. Lara the most effective one