DEFAR - Departamento de Farmácia

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530

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2013 - 20193

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Autor: search.filters.author.Kroon, Erna Geessien

Resultados da Pesquisa

Agora exibindo 1 - 3 de 3
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    Himatanthus bracteatus stem extracts present antiflavivirus activity while an isolated sesquiterpene glucoside present only anti-Zika virus activity in vitro.
    (2019) Silva, Marlene Lourenço da; Stehmann, João Renato; Serafim, Mateus Sá Magalhães; Vale, Valdicley Vieira; Gontijo, Douglas da Costa; Brandão, Geraldo Célio; Kroon, Erna Geessien; Oliveira, Alaíde Braga de
    The hexane and ethanol extracts from Himatanthus bracteatus (Apocynaceae) stems were evaluated for antiviral activity against Zika virus, yellow fever virus and dengue virus 2 and for cytotoxicity in Vero cells by MTT assay. The ethanol extract showed good antiviral activity against the three viruses with selective indexes (SI) > 10 and its fractionation led to the isolation of the known plumieride that was active only against Zika virus (SI of 15.97).
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    Antiviral activity of Fridericia formosa (Bureau) L. G. Lohmann (Bignoniaceae) extracts and constituents.
    (2017) Brandão, Geraldo Célio; Kroon, Erna Geessien; Souza Filho, José Dias de; Oliveira, Alaíde Braga de
    A phytochemical study of Fridericia formosa (Bignoniaceae) ethanol extracts of leaves, stems, and fruits was guided by in vitro assays against vaccinia virus Western Reserve (VACV-WR), human herpes virus 1 (HSV-1), murine encephalomyocarditis virus (EMCV), and dengue virus type 2 (DENV-2) by the MTT method. All the ethanol extracts were active against DENV-2, HSV-1, and VACV-WRwith best results for the fruits extract against DENV-2 (SI > 38.2). For VACV-WRand HSV-1, EC50 values > 200 𝜇g mL−1 were determined, while no inhibition of the cytopathic effect was observed with EMCV. Five compounds were isolated and identified as the C-glucosylxanthones mangiferin (1), 2󸀠-O-trans-caffeoylmangiferin (2), 2󸀠-O-trans-coumaroylmangiferin (3), 2󸀠- O-trans-cinnamoylmangiferin (5), and the flavonoid chrysin (4). The most active compound was 2󸀠-O-trans-coumaroylmangiferin (3) with SI > 121.9 against DENV-2 and 108.7 for HSV-1. These results indicate that mangiferin cinnamoyl esters might be potential antiviral drugs.
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    Chemistry and antiviral activity of Arrabidaea pulchra (Bignoniaceae).
    (2013) Brandão, Geraldo Célio; Kroon, Erna Geessien; Souza, Danielle E. R.; Souza Filho, José Dias de; Oliveira, Alaíde Braga de
    The aim of the present work was to carry out a bioguided isolation of antiviral chemical constituents from an ethanol extract of leaves from Arrabidaea pulchra (Cham.) Sandwith (EEAPL) that had shown in vitro activity in a previous screening using DNA and RNA viruses. The activity of EEPAL was evaluated against the DNA viruses Human herpesvirus 1 (HSV-1) and Vaccinia virus Western Reserve (VACV-WR) as well as against the RNA viruses Murine encephalomyocarditis virus (EMCV), and Dengue virus 2 (DENV-2) by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) colorimetric assay. Cytotoxicity was determined in LLCMK2 and Vero cells and the Selectivity Indexes (SI) were calculated. The most potent effect was observed against DENV-2 (EC50 46.8 ± 1.6 μg mL−1; SI 2.7). For HSV-1 and VACV-WR EC50 values > 200 μg mL−1 were determined, while no inhibition of the cytopathic effect was observed with EMCV. Bioguided fractionation of EEAPL by partition between immiscible solvents followed by chromatography over a Sephadex LH20 column afforded two arylpropanoid glycosides, verbascoside (AP 1) and caffeoylcalleryanin (AP 2), along with a terpenoid, ursolic acid (AP 3). AP 1 and AP 3 exhibited similar anti-DENV-2 profiles, with SI values of 3.8 and 3.1, respectively, while AP 2 was the most effective anti-DENV-2 constituent, with a SI of 20.0. Our results show that A. pulchra leaves ethanol extract (EEAPL) affords compounds with antiviral activity, mainly against DENV-2.