201 research outputs found

    Sesquiterpenes from the essential oil of Laurencia dendroidea (Ceramiales, Rhodophyta): isolation, biological activities and distribution among seaweeds

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    Two known sesquiterpenes (1R*,2S*,3R*,5S*,8S*,9R*)-2,3,5,9-tetramethyltricyclo[6.3.0.0(1,5)]undecan-2-ol and (1S*,2S*,3S*,5S*,8S*,9S*)-2,3,5,9-tetramethyltricyclo-[6.3.0.0(1,5)]undecan-2-ol were isolated for the first time from the essential oil of the red seaweed Laurencia dendroidea collected in the Brazilian coast. These compounds were not active against eight bacteria strains and the yeast Candida albicans, but showed some antioxidant activity. Both compounds were also found in other seaweed species showing that they are not exclusive taxonomic markers to the genus Laurencia.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Ministério da SaúdeMinistério de Ciência e TecnologiaCNPq - INCT-Redoxom

    Assessment of ractopamine in meat and bone meal through LC-MS/MS using solid phase extraction (SPE).

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    Ractopamine (RCT) used as feed additive acts metabolically to decrease fat content contributing to a lean carcass. However, RCT is not broadly accepted worldwide but limited to stringent rules imposed by some countries. To assure human consumption safety, governments are encouraging research institutions to develop sensitive methods to accurately detect and quantify RCT. Yet, little is known about RCT concentration in raw materials such as meat and bone meal (MBM). The effectiveness of a previously developed method for RCT analysis was tested to determine sources of RCT contamination in MBM and discern from potential overestimation in feed

    Carne cultivada de frango: tendências e mercado.

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    No Brasil, apesar deste tipo de proteína ainda não estar sendo comercializada, está em processo de criação o Plano Nacional de Proteínas Alternativas (PNPA), pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA)

    Secretion of iron(III)-reducing metabolites during protein acquisition by the ectomycorrhizal fungus paxillus involutus

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    The ectomycorrhizal fungus Paxillus involutus decomposes proteins using a two-step mechanism, including oxidation and proteolysis. Oxidation involves the action of extracellular hydroxyl radicals (•OH) generated by the Fenton reaction. This reaction requires the presence of iron(II). Here, we monitored the speciation of extracellular iron and the secretion of iron(III)-reducing metabolites during the decomposition of proteins by P. involutus. X-ray absorption spectroscopy showed that extracellular iron was mainly present as solid iron(III) phosphates and oxides. Within 1 to 2 days, these compounds were reductively dissolved, and iron(II) complexes were formed, which remained in the medium throughout the incubation. HPLC and mass spectrometry detected five extracellular iron(III)-reducing metabolites. Four of them were also secreted when the fungus grew on a medium containing ammonium as the sole nitrogen source. NMR identified the unique iron(III)-reductant as the diarylcyclopentenone involutin. Involutin was produced from day 2, just before the elevated •OH production, preceding the oxidation of BSA. The other, not yet fully characterized iron(III)-reductants likely participate in the rapid reduction and dissolution of solid iron(III) complexes observed on day one. The production of these metabolites is induced by other environmental cues than for involutin, suggesting that they play a role beyond the Fenton chemistry associated with protein oxidation
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