Maytenus distichophylla : fitoquímica dos extratos hexânico e clorofórmico das raízes, atividade biológica e cálculos in silico

• Ano de defesa: 2017
• Autor(a) principal: Shirley Alejandra Torres Morales
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: triterpenos pentacíclicos; Celastraceae; câncer de mama e ovário; atividade antibacteriana; Maytenus distichophylla; Química Orgânica; Terpenios; Maytenus Brasil; Agentes antibacterianos; Ressonância magnética nuclear; Agentes antineoplásicos; Produtos naturais
• Link de acesso: http://hdl.handle.net/1843/SFSA-AL3NGN

The phytochemical study of hexane and chloroform root extracts from Maytenus distichophylla was performed yielding natural products from a variety of classes such as friedelane, oleanane, lupane, quinonemethide and steroid compounds. The isolated compounds were identified as 3-oxofriedelane, 3,7-dioxofriedelane, 3-oxo-olean-9(11),12-diene, 11-hydroxylup-20(29)-en-3-one, 30-hydroxylup-20(29)-en-3-one, tingenone and -sitosterol. Furthermore, one triacylglycerol and a mixture of 11[alfa]-hydroxylup-20(29)-en-3-one/pristimerin were also isolated in this study. Their chemical structures were determined by spectroscopic (IR, H and C-NMR) and spectrometric (GC-MS) methods. The antimicrobial activity (antibacterial/antifungal) was evaluated for the extracts and isolated compounds. All substances reduced the viability of Staphylococcus aureus MRSA, however no effect was observed for Candida albicans. The most active samples were tingenone, the mixture of 11-hydroxylup-20(29)-en-3-one/pristimerin and the hexane and chloroform extracts, with a reduction of 75% approximately. The toxicity was also assayed using a Caenorhabditis elegans model in L1 and L4 phase. All tested compounds were non-toxic in L1 phase. However, only the hexane extract and the mixture 11[alfa]-hydroxylup-20(29)-en-3-one/pristimerin allowed the nematodes survival in L4 phase (larval phase used on infection tests). Once these two samples also showed high antibacterial activity, they present themselves as potential candidates to in vivo treatment of bacterial infections. The toxic substances displayed a nematicide potential that could be explored in parasitological studies. Moreover, in silico calculations were performed for 3-oxo-olean-9(11),12-diene, 11[alfa]-hydroxylup-20(29)-en-3-one and 30-hydroxylup-20(29)-en-3-one using the SVM (Support Vector Machine) and Bayes (naive-Bayes Classifier) methods. The lupane compounds showed a potential for treatment of heart diseases and inhibition of [beta]-lactamase enzyme. Also, all three substances displayed promising activity for several types of cancer, mainly breast and ovary cancer.