Constituintes químicos e avaliação da atividade biológica de Xylopia frutescens Aubl. (Annonaceae)

• Ano de defesa: 2019
• Autor(a) principal: Figueiredo, Fiama Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Farmacologia; Programa de Pós-Graduação em Ciências Biológicas; UFPB
• Palavras-chave em Português: Xylopia frutescens; Metabólitos secundários; Atividade antimicrobiana; Cromatografia; Secondary metabolites; Antimicrobial activity; Chromatography; Produtos naturais; Atividade biológica e antimicrobiana; Óleo essencial; CNPQ::CIENCIAS BIOLOGICAS::FARMACOLOGIA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/16280

The Annonaceae family comprises about 2.500 species distributed in 108 genera by tropical and subtropical regions. Among its genera, Xylopia is considered one of the largest, presenting a predominance of alkaloids and diterpenes as secondary metabolites in its species, as well as a great pharmacological potential. Xylopia frutescens, commonly known as "embira-vermelha", is widely used in folk medicine, but few scientific studies are reported for the species. For the study, the X. frutescens stem bark was collected in Santa Rita - PB, dried in a greenhouse at 40 ºC and crushed. The dried powder was extracted with 95% ethanol and the resulting solution was concentrated in a rotary evaporator to give the crude ethanolic extract. This was partitioned, resulting in the hexane, chloroform and ethyl acetate phases. The chemical structures were identified by nuclear magnetic resonance spectroscopy, mass spectrometry and compared with literature data. A precipitate formed in the hexane phase was identified as a mixture of diterpenes: ent-caur-16-en-19-oic acid and enttraquiloban-19-oic acid. The chloroform phase was submitted to medium pressure liquid chromatography, obtaining fractions that were analyzed by high performance liquid chromatography coupled to the diode arrangement detector on an analytical scale and fractionation on a semi-preparative scale, leading to the isolation of four alkaloids and a lignan, identified as pseudopalmatine, oxobuxifoline, lysicamine, laurotetanine and syringaresinol-β-D-glycoside, respectively. The identified substances are being described for the first time for the species, except for laurotetanine. Another fraction of this same phase was analyzed by liquid chromatography coupled to the mass spectrometer, presenting eight main peaks that were putatively identified as aporfinic and oxoaporfinic alkaloids with their substituents. The essential oil was extracted by hydrodistillation in a Clevenger apparatus and characterized by gas chromatography coupled to mass spectroscopy. The chemical composition of the essential oil was monoterpenes and sesquiterpenes, with β-pinene (2.52%), 1,3,5-trimethylbenzene (3.2%), citronellol (1.06%), geraniol 35%), thymol (2.96%), elemol (1.36%), spatulenol (1.08%) and cadin-4-en-10-ol (1.79%) as major constituents. The antimicrobial activity of the essential oil was investigated through the minimum inhibitory concentration (MIC), showing antibacterial activity against Pseudomonas aeruginosa and Morganella morganii (MIC: 1024 μg / mL) and strong antifungal activity against Cryptococcus gattii (INCQS-40113) of 32 μg / mL and 256 μg / mL for Candida tropicalis (ATCC-13803), being classified as a strong antimicrobial potential for complementary studies.