Artigos Científicos - ICEN

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2557

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Navegando Artigos Científicos - ICEN por Autor "ARRUDA, Alberto Cardoso"

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    Flavonoids from the leaves of Deguelia utilis (Leguminosae): structural elucidation and neuroprotective properties
    (2012-10) OLIVEIRA, Dalglish Gomes de; ALMEIDA, Cecília M. C. de; SILVA, Consuelo Yumiko Yoshioka e; ARRUDA, Mara Silvia Pinheiro; ARRUDA, Alberto Cardoso; LOPES, Dielly Catrina Favacho; YAMADA, Elizabeth Sumi; COSTA, Edmar Tavares da; MARTINS FILHO, Arnaldo Jorge; SILVA, Milton Nascimento da
    Five new flavonoids, 5,3'-dihydroxy-4'-methoxy-2'',2''-dimethylchromene-(5'',6'':6,7)dihydroflavonol (1), 5,3'-dihydroxy-7,4'-dimethoxy-6,8-dimethylallyl-dihydroflavonol (2), 5,3'-dihydroxy-4'-methoxy-8-allyl-2'',2''-dimethylchromene-(5'',6'':6,7) flavanone (3), 5,3'-dihydroxy-7,4'-dimethoxy-6,8-dimethylallyl-flavanone (4), 3,5,3'-trihydroxy-7,4'-dimethoxy6,8-dimethylallyl-flavanol (5), together with the stilbenes 4-methoxylonchocarpene (6) and lonchocarpene (7) were isolated from the leaves of Deguelia utilis. Their chemical structures were established on the basis of NMR (nuclear magnetic resonance) spectral data and HRESITOF-MS (electrospray ionization-high resolution time-of-flight mass spectrometry). Also, in order to investigate potential cytoprotective effects of these flavonoids, we used a fraction eluted with hexane:EtOAc containing all seven flavonoids, in an in vitro model of neurodegeneration, using hippocampal primary cultures from neonatal (PND2-P3) rats exposed to rotenone, a mitochondrial complex I inhibitor. There was a significant reduction in cell viability (19.4 ± 1.6%) when the cultures were exposed to 30 nmol L-1 rotenone for 72 h. Concomitant exposure of the cultures to the FR3 (5 µg mL-1) and 30 nmol L-1 rotenone resulted in values of cell viability similar to control groups (99.6 ± 4.8%), strongly suggesting a cytoprotective effect for this flavonoid-rich fraction.
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    New isoflavones from the leaves of Vatairea guianensis Aublé
    (2013-11) SOUZA, Ronilson Freitas de; MARINHO, Victor Hugo de Souza; SILVA, Geilson Alcantara da; COSTA JUNIOR, Livio Martins; SILVA, Joyce Kelly do Rosário da; BASTOS, Gilmara de Nazareth Tavares; ARRUDA, Alberto Cardoso; SILVA, Milton Nascimento da; ARRUDA, Mara Silvia Pinheiro
    Four isoflavones were isolated from Vatairea guianensis Aublé leaves and identified as 5,3'-dihydroxy-4'-methoxy-2",2"-dimethylpyrano-(5",6":8,7)-isoflavone ( 1: ), 5,7-dihydroxy-3',4'-methylenedioxy-8-prenyl-isoflavone ( 2: ), 5,3'-dihydroxy-4'-methoxy-7-O-β-glucopyranoside-8-prenyl-isoflavone ( 3: ) and derrone ( 4: ) together with five triterpenes identified in mixture, lupeol, α-amyrin, β-amyrin, germanicol and betulinic acid. Substances 1: 3: are novel natural products, although 1: and 2: have been cited as synthetic products. However, all these compounds are first reported from this species. Their chemical structures were elucidated based on their 1D and 2D nuclear magnetic resonance (NMR) data and high resolution mass spectrometry. The ethanol extract from the leaves and 1: 3: were evaluated for their potential in scavenging DPPH• (2,2-diphenyl-1-picrylhydrazylradical) and the results showed that the extract presented high activity (IC50 = 6.2 ± 0.4 µg mL-1), while the isolated compounds showed low antioxidant power (IC50 ≥ 29.5 ± 2.5 µg mL-1) when compared to Trolox (IC50 = 4.5 ± 0.4 µg mL-1).
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    A New Prenylisoflavone from the Antifungal Extract of Leaves of Vatairea guianensis Aubl.
    (Universidade Federal do Pará, 2017-06) SOUZA, Ronilson Freitas de; SILVA, Geilson Alcantara da; ARRUDA, Alberto Cardoso; SILVA, Milton Nascimento da; SANTOS, Alberdan Silva; GRISÓLIA, Daniella Paternostro de Araújo; SILVA, Moisés Batista da; ARRUDA, Mara Silvia Pinheiro
    A new compound, 5,7,3'-trihydroxy-4'-methoxy-8-prenylisoflavone, was isolated from the leaves of Vatairea guianensis Aubl. (Fabaceae), together with two known isoflavones lupiwighteone and 5,7,4'-trihydroxy-3'-methoxy-8-prenylisoflavone. All isolated compounds were characterized based on infrared (IR), UV, 1H and 13C nuclear magnetic resonance (NMR), including 2D NMR analyses and high resolution mass spectrometry. The ethanolic extract from V. guianensis leaves displayed activity against Candida dubliniensis, C. albicans and C. krusei. However, the EtOAc fraction from that extract exhibited more significant activity than the ethanolic extract, showing antifungal activity for all fungi species investigated. The major compound 5,7,3'-trihydroxy-4'-methoxy-8-prenylisoflavone isolated from that EtOAc fraction was also active against C. parapsilosis and C. dubliniensis.
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