Maytenus ilicifolia: isolamento de alcaloides e potencial antimicrobiano, antiparasitário, antioxidante e citotóxico

• Ano de defesa: 2025
• Autor(a) principal: Paz, Luísa Helena Alves
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Química; UFSM; Programa de Pós-Graduação em Química; Centro de Ciências Naturais e Exatas
• Palavras-chave em Português: Maytenus ilicifolia; Espinheira-santa; Alcaloides; Evonina; Euonimina; Aquifoliunina E-I; Maiteína; Antimicrobiana; Antioxidante; Antiparasitária; Alkaloids; Evonine; Euonymine; Mayteine; Antimicrobial; Antioxidant; Antiparasitary; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/34575

The use of medicinal plants is an ancient practice, directly connected to the evolution of human beings. Therefore, it is essential to promote research that ensures the safe and effective use of natural products by the population. In this context, the plant Maytenus ilicifolia, known popularly as “espinheira-santa”, was selected as the focus of the study. This species has been widely used in traditional medicine, particularly for gastrointestinal diseases. Initially, to obtain the crude methanolic extract from the M. ilicifolia root bark, a study was carried out using the following traditional extraction methodologies: maceration (EBM), ultrasonic bath (EBU) and soxhlet extractor (EBS). Subsequently, a liquid-liquid partitioning with organic solvents was employed, generating the fractions: FHS, FCS, FAS, FBS. Chromatographic purification methods were applied, leading to the isolation of six compounds: the alkaloids evonine (MC5), euonymine (MC7), aquifoliunine E-1 (MC9) and mayteine (M10) and the compounds epigallocatechin (M14) and β-sitosterol (M25). The pharmacological profile of the extracts, fractions and alkaloids was determined based on their antimicrobial, antioxidant, cytotoxic and antiparasitary activities. From the study of extraction methodologies, the EBS method was chosen to continue the work because it presents a higher yield to obtain the EBS methanolic crude extract (28.69%). The extracts EBS, EBM and EBU as well as the fractions FHS, FCS, FAS and FBS, demonstrated the ability to inhibit microbial growth of different strains at various concentrations. The most prominent antimicrobial activity was observed for the fraction FCS and its alkaloids evonine, aquifoliunine E-1 and mayteine, showing a MIC50 of 3.125 and 6.25 µg mL-1 against Bacillus cereus and Shigella sonnei. The extract EBS and the fractions FHS, FCS, FAS and FBS did not exhibit toxicity against non-tumor cells. The alkaloids evonine and mayteine promoted na increase of approximately 150% in the cell proliferation of HaCaT cells. FAS and FCS resulted in a reduction in reactive oxygen species, indicating their potential as inhibitors of oxidative stress. The DPPH free radical scavenging method indicated the antioxidant activity of the fractions FAS and FBS with IC50 values of 14.82 and 15.28 µg mL1 , respectively. The antiparasitary activity was determined against Trichomonas vaginalis and Trichomonas gallinae. The extracts EBS and EBM and the fractions FAS and FBS were able to inhibit the growth of the parasites.