Mechanism of the vasodilator effect of mono-oxygenated xanthones: a structure-activity relationship study

Registro completo de metadados
MetadadosDescriçãoIdioma
Autor(es): dc.creatorDiniz, Thiago Frederico-
Autor(es): dc.creatorPereira, Aline Carvalho-
Autor(es): dc.creatorCapettini, Luciano-
Autor(es): dc.creatorSantos, Marcelo Rodrigues dos-
Autor(es): dc.creatorNagem, Tanus Jorge-
Autor(es): dc.creatorLemos, Virgínia Soares-
Autor(es): dc.creatorCôrtes, Steyner de França-
Data de aceite: dc.date.accessioned2026-02-09T12:44:55Z-
Data de disponibilização: dc.date.available2026-02-09T12:44:55Z-
Data de envio: dc.date.issued2016-09-01-
Data de envio: dc.date.issued2016-09-01-
Data de envio: dc.date.issued2013-
Fonte completa do material: dc.identifierhttps://repositorio.ufla.br/handle/1/11722-
Fonte completa do material: dc.identifierhttps://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0033-1350803.pdf-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/capes/1167491-
Descrição: dc.descriptionThe present study characterized the mechanisms involved in the vasodilator effect of two mono-oxygenated xanthones, 4-hydroxyxanthone and 4-methoxyxanthone. 9-Xanthenone, the base structure of xanthones, was used for comparison. 4-Hydroxyxanthone and 9-xanthenone induced a concentration-dependent and endothelium-independent vasodilator effect in arteries precontracted with phenylephrine (0.1 µmol · L−1) or KCl (50 mmol · L−1). 4-Methoxyxanthone induced a concentration-dependent vasodilator effect in arteries precontracted with phenylephrine, which was partially endothelium-dependent, and involved production of nitric oxide. In endothelium-denuded arteries precontracted with KCl, the vasodilator effect of 4-methoxyxanthone was abolished. The vasodilator effect of 4-hydroxyxanthone (96.22 ± 2.10 %) and 4-methoxyxanthone (96.57 ± 12.40 %) was significantly higher than observed with 9-xanthenone (53.63 ± 8.31 %). The presence of an oxygenated radical in position 4 made 4-hydroxyxanthone (pIC50 = 4.45 ± 0.07) and 4-methoxyxanthone (pIC50 = 5.04 ± 0.09) more potent as a vasodilator than 9-xanthenone (pIC50 = 3.92 ± 0.16). In addition, 4-methoxyxanthone was more potent than the other two xanthones. Ca2+ transients in vascular smooth muscle cells elicited by high K+ were abolished by 4-hydroxyxanthone and 9-xanthenone. The endothelium-independent effect of 4-methoxyxanthone was abolished by inhibition of K+ channels by tetraethylammonium. The current work shows that an oxygenated group in position 4 is essential to achieve Emax and to increase the potency of xanthones as vasodilators. Substitution of an OH by OCH3 in position 4 increases the potency of the vasodilator effect and changes the underling mechanism of action from the blockade of L-type calcium channels to an increase in NO production and activation of K+ channels.-
Idioma: dc.languageen-
Publicador: dc.publisherThieme Medical Publishers-
Direitos: dc.rightsrestrictAccess-
???dc.source???: dc.sourcePlanta Medica-
Palavras-chave: dc.subjectXanthones-
Palavras-chave: dc.subject4-hydroxyxanthone-
Palavras-chave: dc.subject4-methoxyxanthone-
Palavras-chave: dc.subjectVasodilation-
Palavras-chave: dc.subjectCa2+ channels-
Palavras-chave: dc.subjectNitric oxide-
Palavras-chave: dc.subjectK+ channels-
Título: dc.titleMechanism of the vasodilator effect of mono-oxygenated xanthones: a structure-activity relationship study-
Tipo de arquivo: dc.typeArtigo-
Aparece nas coleções:Repositório Institucional da Universidade Federal de Lavras (RIUFLA)

Não existem arquivos associados a este item.