Definição do perfil fitoquímico por LC/MS e primeiros metabolitos isolados de Sida planicaulis Cav. (Malvaceae) e atividade antimicrobiana

Abstract

It is considered that the millennial use of medicinal plants for the purpose of curing the diseases of mankind, has provided a vast knowledge on the therapeutic actions and the toxicity of certain species. In spite of the richness of the Brazilian flora, in the last 20 years, the number of information on medicinal plants has grown only 8% annually. Aiming to contribute with that scientific enrichment, the present study carried out a pioneering phytochemical work of Sida planicaulis Cav., aiming at the discovery its chemical constituents and antimicrobial action, and thus collaborate with the chemotaxonomic enrichment of the Malvaceae family. In order to reach these objectives, we used chromatographic and spectroscopic techniques, using Nuclear Magnetic Resonance (NMR), uni and bidimensional, and Mass Spectrometry. With the methodology used it was possible to isolate a coumarin (Esculetin) and an alkaloid (Salt of cryptolepin) and to identify by FIA-ESI-IT-MS eight secondary metabolites, among them phenolic acids and glycosylated flavonoids, for example: tilirosideo, rutin and astragalin. Among the samples that tested its antimicrobial activity, the salt of cryptolepin was the most promising MIC against Candida albicans LM-38, Escherichia coli LM-35, Cryptococcus gatti IHCQS-40113, Cryptococcus neoformans LM-49 and Candida albicans ATCC-60193, having a pharmacological activity considered to be optimum to moderate, and may therefore be the target of future microbiological tests.