Publications by authors named "Gabriela B Grimaldi"

2 Publications

  • Page 1 of 1

Production of Highly Active Antiparasitic Compounds from the Controlled Halogenation of the Crude Plant Extract.

J Nat Prod 2020 09 9;83(9):2631-2640. Epub 2020 Sep 9.

School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland (ISPSW), University of Geneva, CMU, Rue Michel Servet 1, 1211 Geneva 4, Switzerland.

Direct halogenation of phenolic compounds present in the CHCl extract of the roots of was investigated to enhance chemodiversity. The approach is based on eco-friendly reactions using NaBr, NaI, and NaCl in aqueous media to generate multiple "unnatural" halogenated natural products from crude extracts. The halogenation reactions, monitored by UHPLC-PDA-ELSD-MS, were optimized to generate mono-, di-, or trihalogenated derivatives. To isolate these compounds, the reactions were scaled up and the halogenated analogues were isolated by semipreparative HPLC-UV and fully characterized by NMR and HR-MS data. All of the original 16 halogenated derivatives were evaluated for their antiparasitic activities against the parasites and . Compounds presenting selective antiparasitic activities against one or both parasites with IC values comparable to the reference were identified.
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September 2020

Antileishmanial Activity of Dimeric Flavonoids Isolated from .

Molecules 2018 Dec 20;24(1). Epub 2018 Dec 20.

Laboratório de Engenharia Tecidual e Imunofarmacologia, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz), Avenida Waldemar Falcão, 121, Candeal⁻Salvador-BA 40296-710, Brazil.

Leishmaniasis are diseases caused by parasites belonging to genus. The treatment with pentavalent antimonials present high toxicity. Secondary line drugs, such as amphotericin B and miltefosine also have a narrow therapeutic index. Therefore, there is an urgent need to develop new drugs to treat leishmaniasis. Here, we present the in vitro anti-leishmanial activity of unusual dimeric flavonoids purified from . Three compounds were tested against sp. Compound 2 was the most active against promastigotes. Quantifying the in vitro infected macrophages revealed that compound 2 was also the most active against intracellular amastigotes of , without displaying host cell toxicity. Drug combinations presented an additive effect, suggesting the absence of interaction between amphotericin B and compound 2. Amastigotes treated with compound 2 demonstrated alterations in the Golgi and accumulation of vesicles inside the flagellar pocket. Compound 2-treated amastigotes presented a high accumulation of cytoplasmic vesicles and a myelin-like structure. When administered in -infected mice, neither the oral nor the topical treatments were effective against the parasite. Based on the high in vitro activity, dimeric flavonoids can be used as a lead structure for the development of new molecules that could be useful for structure-active studies against .
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December 2018