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Leiothrix (Eriocaulaceae) é um gênero exclusivo da América do Sul, com 37 espécies restritas ao Brasil. Leiothrix flavescens (Bong.) Ruhland e Leiothrix curvifolia (Bong.) Ruhland, são espécies endêmicas em áreas dos Estados de Minas Gerais e Bahia. Existem na literatura poucos estudos químicos e biológicos realizados com espécies desse gênero. Neste trabalho, foi estudada a atividade antioxidante pelo ensaio TEAC (Trolox Equivalent Antioxidant Capacity) e de autoxidação, utilizando ácido linoléico, de xantonas isoladas dos extratos etanólicos de L. curvifolia e L. flavescens. As substâncias apresentaram moderada atividade antioxidante, quando comparadas com padrões de quercetina e de BHT (2, 6 - ditercbutil - 4 - metóxifenil).

Leiothrix (Eriocaulaceae) is an exclusively South American genus of which 37 species are restricted to Brazil. Leiothrix flavescens (Bong.) Ruhland and Leiothrix curvifolia (Bong.) Ruhland, are species endemic to areas of Minas Gerais and Bahia States. Chemical and biological investigations of this genus are scarse. The objective of this work was to investigate the antioxidant effect using TEAC and linoleic acid assays of the xanthones isolated from the ethanolic extract of these species. These substances showed a moderate antioxidant activity when compared to quercetin and to BHT.

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Three new naphthopyranone glycosides, paepalantine-9-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (1), paepalantine-9-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (2), and paepalantine-9-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3), along with the known paepalantine-9-O-beta-D-glucopyranoside (4) were isolated from aerial parts of Paepalanthus microphyllus. These compounds were characterized by spectrometric methods, including electrospray mass spectrometry and 1D and 2D NMR experiments. As a part of our program for screening natural compounds for anti-HIV activity, compounds 1-4 were tested in C8166 cells infected with HIV-1MN.

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8-Carboxymethyl-1,6-dihydroxy-3,5-dimethoxyxanthone, 8-carboxymethyl-1,5,6-trihydroxy-3-methoxyxanthone and 8-carboxymethyl-1,3,5,6-tetrahydroxyxanthone were isolated from the capitula of Leiothrix curvifolia and Leiothrix flavescens and characterized by spectroscopic methods, mainly 1D and 2D NMR experiments, as well as by electrospray mass spectrometry. Eight known flavonoids were also isolated and they were identified by 1D and 2D NMR experiments and comparison with literature data.

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A new naphthopyranone dimer (1) named planifolin was isolated from a methylene chloride extract of the capitula of Paepalanthus planifolius. The structure of 1 has been determined by chemical and spectroscopic means. In addition, a known dihydronaphthopyranone glycoside and seven known flavonoids were isolated from an ethanolic extract of the leaves of P. planifolius.

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La evaluación del balance nitrogenada en pacientes criticos y en aquellos que reciben soporte nutricional se realiza con la estimación de las pérdidas de nitrógeno en orina midiendo en nitrogeno ureico urinario (NUU), el que representa la mayor parte de las plérdidas nitrogenadas. Dado que contamos con la posibilidad de realizar la determinación de nitrógeno total urinario (NTU) quisimos evaluar el impacto del soporte nutricional en el balance nitrogenado de los pacientes críticos. Objetivos: 1. evaluar el balance nitrogenado de los pacientes internados en terapia intensiva (UTI). 2. estudiar la evaluación del balance nitrogenado en pacientes ayunados y su evolución en el curso del soporte nutricional ... (AU)

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La evaluación del balance nitrogenada en pacientes criticos y en aquellos que reciben soporte nutricional se realiza con la estimación de las pérdidas de nitrógeno en orina midiendo en nitrogeno ureico urinario (NUU), el que representa la mayor parte de las plérdidas nitrogenadas. Dado que contamos con la posibilidad de realizar la determinación de nitrógeno total urinario (NTU) quisimos evaluar el impacto del soporte nutricional en el balance nitrogenado de los pacientes críticos. Objetivos: 1. evaluar el balance nitrogenado de los pacientes internados en terapia intensiva (UTI). 2. estudiar la evaluación del balance nitrogenado en pacientes ayunados y su evolución en el curso del soporte nutricional ...

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Three new compounds-3, 4-dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho- ]2, 3c]-pyran-1-one-9-O-beta-D-glucopyranoside (1), 3, 4-dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho- [2, 3c]-pyran-1-one-9-O-beta-D-glucopyranosyl-(1-->6)-glucopyranoside (2), and 3,4-dihydro-10-dihydroxy-7-methoxy-3-(R)-methyl-1H-3, 4-dihydronaphtho-[2,3c]-pyran-1-one-9-O-beta-D-allopyranosyl (1-->6)glucopyranoside (3)-were isolated from the leaves of Paepalanthus vellozioides and Paepalanthus latipes and characterized by spectrometric methods, mainly electrospray mass spectrometry and 1D and 2D NMR experiments. These unusual glycosylated dihydronaphthopyranones may serve as taxonomic markers of the genus Paepalanthus, since these compounds were not detected in other genera belonging to the Eriocaulaceae family.

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Five new flavonol 7-O-glycosides (1-5), having quercetin or quercetin 3-methyl ether as their aglycons, and sugar chains made up of three or four sugars, including beta-D-glucopyranose, alpha-L-rhamnopyranose, and beta-D-xylopyranose, have been isolated from the aerial parts of Bidens andicola, along with a new chalcone ester glycoside (6) and five known chalcone ester glycosides. The structures of 1-6 were elucidated using a combination of spectroscopic techniques.

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The MeOH extract of the aerial parts of Croton ruizianus afforded two new pregnane glycosides 1 and 2, together with the morphinandienone alkaloids flavinantine (3) and O-methylflavinantine (4). Their structures were elucidated by NMR experiments including 1H-1H (1D TOCSY and 2D DQF-COSY) and 1H-13C (HSQC, HMBC) spectroscopy. The proaggregating activity of the MeOH extract and the isolates were evaluated. Although the MeOH extract and pregnane glycosides (at different doses) were found to promote platelet aggregation, flavinantine (3) and O-methylflavinantine (4) showed only slight activity. The ability of the MeOH extract and the four compounds to act synergistically with thrombin was also evaluated. All the tested compounds were successful in augmenting the aggregating effect of thrombin, although to different degrees.

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Six new oleanene glycosides were isolated from the MeOH extract of the aerial parts of Spergularia ramosa. They possess gypsogenin or quillaic acid as the aglycons. The disaccharide moiety linked to C-3 of the aglycons is made up of galactose (or glucose) and glucuronic acid (or glucose); the pentasaccharide moiety linked to C-28 is made up of glucose (or galactose), xylose, rhamnose, fucose, and arabinose. Their structures were elucidated by 1D and 2D NMR experiments including 1H-1H (DQF-COSY, 1D TOCSY, 2D HOHAHA, ROESY) and 1H-13C (HSQC, HMBC) spectroscopy.

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The present study examined the effect of the MeOH extract, partially purified fraction (IV), and pure compounds from Argemone mexicana L. (Papaveraceae) on the morphine withdrawal in guinea pig isolated ileum. The MeOH extract, the partially purified fraction (IV), and the pure compounds isolated from A. mexicana significantly and in a concentration-dependent manner reduced the morphine withdrawal. Since the pure compounds were identified as protopine and allocryptopine, the observed effects could be related to these compounds. The results of the present study suggest that isoquinoline alkaloids may be potential agents in the treatment of drug abuse.

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