390 research outputs found

    Chemical and antioxidative assessment of dietary turnip (Brassica rapa var. rapa L.)

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    The phenolic compounds and organic acids of turnip (Brassica rapa var. rapa L.) edible parts (leaves and stems, flower buds and roots) were determined by HPLC–DAD and HPLC–UV, respectively. The results revealed a profile composed of 14 phenolics (3-p-coumaroylquinic, caffeic, ferulic and sinapic acids, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside-7-O-sophoroside, kaempferol 3-O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, kaempferol 3,7-O-diglucoside, isorhamnetin 3,7-O-diglucoside, kaempferol 3-O-sophoroside, 1,2-disinapoylgentiobiose, 1,20-disinapoyl-2-feruloylgentiobiose, kaempferol 3-O-glucoside and isorhamnetin 3-O-glucoside) and six organic acids (aconitic, citric, ketoglutaric, malic, shikimic and fumaric acids). The quantification of the identified compounds showed kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, isorhamnetin 3,7-O-diglucoside and isorhamnetin 3-O-glucoside as the main phenolics, and malic acid as the organic acid present in highest amounts. A screening of the antioxidative potential was also performed by means of the DPPH radical scavenging assay. Turnip flower buds exhibited the strongest antioxidant capacity

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

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    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

    Systemic release of volatiles by Brassica oleracea var. acephala induced by Pieris brassicae predation.

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    Pieris brassicae is a specialist on crucifers and its interactions with some of its host plants have been increasingly studied given their importance in pest management, chemical ecology and entomology. Plants are known to respond to insect attack by releasing volatiles that can either warn neighbour plants to the presence of a predator or attract insect parasitoids, thus reducing the attack efficiency. The influence of P. brassicae feeding on Brassica oleracea L. var. acephala (kale) was investigated, namely, its effect in the volatiles released by the plant through time. Substantial differences, mainly quantitative, were found between the volatiles composition of B. oleracea var. acephala before the attack and after insect feeding. More than 40 compounds were found, between terpenes (monoterpenes and sesquiterpenes) and lipoxygenase pathway byproducts (alcohols and aldehydes), ketones, norisoprenoids, among others. After insect attack, monoterpenes like limonene, eucalyptol, camphor and caryophyllene increased noticeably. These compounds have been regarded as markers in local tissue responses and in this study an increase in their concentration was detected at 1 and 4 hours after feeding, with subsequent reduction after 8 hours. Menthol, menthone, phenol and sabinene were found only in the time following the attack. A considerable increase in hexenyl acetate, a well known semiochemical, was also found, with this compound being the major peak in all experiments, rising with time. These findings provide further knowledge of the ecological interactions between these two species and, given the chemical diversity of these matrices, they may constitute a good source of health promoting compounds.Fundação para a Ciência e Tecnologia for financial support (PTDC/AGRAAM/ 64150/2006). F. Fernandes (SFRH/BD/37963/2007

    Metabolic fate of dietary volatile compounds in Pieris brassicae

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    In this work, the evolution of the qualitative and quantitative profile of the volatile fraction of Pieris brassicae after feeding on Brassica oleracea var. acephala (kale) was monitored through time. HS-SPME/GC-MS was applied to both the host plant and the living insect and its excrements. A total of seventy seven compounds (lipoxygenase pathway by-products, nitrogen compounds, norisoprenoids, sulphur compounds, terpenes, among others) were identified. Thirty eight compounds were identified in insect after 2 h of starvation and forty eight compounds in excrements. Qualitative and quantitative changes were detected along time. Dimethyldisulfide, dimethyltrisulfide, limonene and eugenol were major compounds for all analysed times in both matrices, being limonene an important compound in insect after starvation. The accumulation by P. brassicae of some compounds, such as limonene, was verified, suggesting a mechanism by which the insect can take benefit from bioactive constituents from the diet. Along with accumulation, complete excretion of some compounds, including nitrogen bearing compounds, by-products of glucosinolates was detected. These results reflect one of the strategies used to overcome plant barriers, namely detoxification of toxic compounds. The findings contribute to the knowledge of the metabolization of the volatile compounds in insects and contribute to the body of knowledge of this ecologic system.FC

    Agri-food surplus, waste and loss as sustainable biobased ingredients: a review

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    Ensuring a sustainable supply of food for the world’s fast growing population is a major challenge in today’s economy, as modern lifestyle and increasing consumer concern with maintaining a balanced and nutritious diet is an important challenge for the agricultural sector worldwide. This market niche for healthier products, especially fruits and vegetables, has increased their production, consequently resulting in increased amounts of agri-food surplus, waste, and loss (SWL) generated during crop production, transportation, storage, and processing. Although many of these materials are not utilized, negatively affecting the environmental, economic, and social segments, they are a rich source of valuable compounds that could be used for different purposes, thus preventing the losses of natural resources and boosting a circular economy. This review aimed to give insights on the efficient management of agri-food SWL, considering conventional and emerging recovery and reuse techniques. Particularly, we explored and summarized the chemical composition of three worldwide cultivated and consumed vegetables (carrots, broccoli and lettuce) and evaluate the potential of their residues as a sustainable alternative for extracting value-added ingredients for the development of new biodynamic productsThe authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through the national funds FCT/MCTES to CIMO (UIDB/00690/2020) and national funding by FCT, P.I., through the institutional scientific employment program contract for L. Barros and A. Fernandes.info:eu-repo/semantics/publishedVersio

    Enhancement of resistivity and magnetization of Bi1-xLaxFe1-yMnyO3 ceramics by composition optimization

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    This work aims at studying the effect of La and Mn substituents on the structural, electrical and magnetic properties of Bi1-xLaxFe1-yMnyO3 (0≤x≤0.30; 0≤y≤0.20) at room temperature, in order to find out the optimal compositions that provide both high resistivity and remnant magnetization. The analysis of the XRD patterns and Raman spectra suggest a progressive transition from a rhombohedral for x0.20. Moreover, we observe satellite peaks associated with an incommensurate modulated (IM) orthorhombic structure for x≥0.15 with y = 0, and x = 0.20 with y = 0.10. We were able to achieve a decrease by several orders of magnitude of the leakage current density and the emergence of a weak ferromagnetic response in the range of compositions 0.10<x≤0.3 and 0<y<0.1. These improved physical properties are a consequence of the absence of secondary phases and the breaking of the spiral cycloid spin structure. In particular, the compositions within 0.18≤x≤0.30 and 0.01<y<0.05 with IM orthorhombic structure exhibit the lowest conductivity and highest remnant magnetization. The outcome of this work suggests an alternative route to enhance multiferroic properties of BiFeO3, with simultaneous La (0.10≤x≤0.30) and moderate Mn (0.01<y<0.1) substitution.publishe

    Phenolic compounds and bioactive properties of Ruscus aculeatus L. (asparagaceae): the pharmacological potential of an underexploited subshrub

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    Ruscus aculeatus L. is a subshrub used in traditional medicine in different parts of the world, namely in Europe and the Iberian Peninsula. According to reported folk knowledge, the aerial parts are mainly used as diuretics and the underground organs are used for the treatment of disorders of the urinary system and as a laxative. In this work, the aerial part and the roots and rhizomes of R. aculeatus were chemically characterized with regard to the content of phenolic compounds and bioactive properties. Aqueous (infusions and decoctions) preparations and hydroethanolic extracts from the two mentioned parts of the plant were prepared. Nine phenolic compounds were detected in all the extracts. Apigenin-C-hexoside-C-pentoside isomer II was the major compound in aqueous extracts and, in the hydroethanolic extract was quercetin-O-deoxyhexoside-hexoside followed by apigenin-C-hexoside-C-pentoside isomer II. All extracts revealed antioxidant activity and potential to inhibit some of the assayed bacteria; aqueous extracts of the aerial part and infusions of roots and rhizomes did not show cytotoxic effects on a non-tumor primary cell culture. This preliminary study provides suggestions of the biological potential associated with the empirical uses and knowledge of this species, in particular its bioactivities.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through the national funds FCT/MCTES to CIMO (UIDB/00690/2020) and national funding by FCT, P.I., through the institutional scientific employment program contract for L. Barros, A. Fernandes, M.I. Dias, C. Pereira, and R.C. Calhelha. The authors are also grateful to FEDER-Interreg España-Portugal program for financial support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P and to European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project Norte-01-0145-FEDER- 000042: GreenHealth.info:eu-repo/semantics/publishedVersio

    Bioactive properties of Ruscus aculeatus L.: na underexploited subshrub

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    Ruscus aculeatus L. is a sub-shrub used in traditional medicine in different parts of the world, namely in Europe and the Iberian Peninsula[1]. Traditionally, the aerial parts are mainly used as diuretics and the underground parts are used for the treatment of urinary tract diseases and as a laxative[2]. In the present work, the aerial part, roots, and rhizomes of R. aculeatus were characterized regarding their bioactive properties in order to contribute to the knowledge of the chemical composition of this unexplored species. The plant material of R. aculeatus was harvested in April 2019 inside woodlands and hedgerows, in Valpaços, Portugal. Two distinct parts were gathered: the aerial part (cladodes or laminar stems and lateral branches) and the underground organs (rhizomes with roots). Hydroethanolic extracts and aqueous (infusions and decoctions) preparations from the two mentioned parts of the plant were prepared. Multi-resistant clinical bacterial strains (Enterococcus faecalis, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Morganela morganii, Proteus mirabilis and Pseudomonas aeruginosa) were used to screen the antimicrobial activity and the antioxidant activity was evaluated through two different in vitro assays: inhibition of lipid peroxidation in brain homogenates by thiobarbituric acid reactive substances (TBARS) and oxidative hemolysis inhibition assay (OxHLIA). The cytotoxic activity was assayed using MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung carcinoma), HeLa (cervical carcinoma) and HepG2 (hepatocellular carcinoma) human tumor cell lines, and also a non-tumor cell line (porcine liver primary cells, PLP2). All extracts revealed antioxidant activity and potential to inhibit some of the assessed bacteria; except for the infusion of the aerial part (for the lines MCF7 and HepG2) and decoction extracts (line MCF7), all the remaining extracts presented effective results in the inhibition of the tested cell lines; the aqueous extracts of the aerial part and infusions of roots and rhizomes did not show cytotoxic effects in a non-tumor primary cell culture. This preliminary study provided innovative and interesting results in relation to the bioactive properties of this little-studied and explored wild plant.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and national funding by FCT, P.I., through the institutional scientific employment program-contract for L. Barros, A. Fernandes, C. Pereira and R.C. Calhelha´s contract. The authors are grateful to the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project Norte-01-0145-FEDER-000042: GreenHealth.info:eu-repo/semantics/publishedVersio

    Pieris brassicae excrements: cytological effects

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    Attention has been focused on identifying naturally occurring compounds with anticarcinogenic activity. Epidemiological data evidence the protective role of Brassica species, especially due to their phenolics and glucosinolates. Pieris brassicae, an insect whose larvae constitutes a frequent pest of Brassica species, has the capacity to uptake, metabolize and excrete these phytochemicals by the faeces. Phenolics composition of excrements from P. brassicae reared on Brassica oleracea var. acephala presents flavonoids (sulfated and glycosilated), some of them not detected in host plant [1]. Their volatiles profile shows compounds belonging to different classes, with especial attention to terpenes and glucosinolates breakdown products (sulfur and nitrogen compounds) [2]. Furthermore, this matrix already revealed to have antioxidative properties [1]

    The Fueling and Evolution of AGN: Internal and External Triggers

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    In this chapter, I review the fueling and evolution of active galactic nuclei (AGN) under the influence of internal and external triggers, namely intrinsic properties of host galaxies (morphological or Hubble type, color, presence of bars and other non-axisymmetric features, etc) and external factors such as environment and interactions. The most daunting challenge in fueling AGN is arguably the angular momentum problem as even matter located at a radius of a few hundred pc must lose more than 99.99 % of its specific angular momentum before it is fit for consumption by a BH. I review mass accretion rates, angular momentum requirements, the effectiveness of different fueling mechanisms, and the growth and mass density of black BHs at different epochs. I discuss connections between the nuclear and larger-scale properties of AGN, both locally and at intermediate redshifts, outlining some recent results from the GEMS and GOODS HST surveys.Comment: Invited Review Chapter to appear in LNP Volume on "AGN Physics on All Scales", Chapter 6, in press. 40 pages, 12 figures. Typo in Eq 5 correcte
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