Extração e caracterização de metabólitos secundários de Aloysia virgata (Ruíz & Pavón) JUSS

Abstract

Throughout the history of mankind, plants with medicinal power have been used to cure diseases and wounds, and to prove these activities, studies on these methods of natural healing of diseases have grown. Among the botanical families traditionally with medicinal specimens or with medicinal potential, stands out Verbenaceae, family with species widely used by folk medicine and which still has few studies related to its chemical composition. In this context, the species Aloysia virgata, popularly known as trash, is very popular in South America to treat symptoms of diseases related mainly to the digestive system. Despite being widely consumed by the general population, most studies concerning this plant are focused on its essential oil and there is little scientific work relating the secondary metabolism chemicals responsible for its biological activities. Thus, in this work the leaves of A. virgata were submitted to extraction with distilled water, simulating the popularly consumed tea, and hydroacoolic, in order to isolate and structurally identify the main chemical constituents present in its leaves in different forms of extraction. In order to separate high molecular weight compounds from low mass compounds, the crude extracts were precipitated with refrigerated ethyl alcohol, resulting in ethanol-soluble fractions containing secondary metabolites, called AV-SBH for hydroalcoholic extract and AV-SBA for the aqueous extract. The aqueous and hydroalcoholic extracts presented similar chemical composition, but abundance of different compounds. AV-SBH presented the major peak as hoffmaniacetone, being identified by the first as the largest compound for A. virgata, and AV-SBA presented higher concentration campferol / luteolin diglycoside, which was first described in the plant. In addition, another unpublished compound was also found in both extracts, campferol / luteolin triglycoside. Some metabolites present in the extracts can be quantified by external standardization. Of these, the major ones were p-coumaric acid and rutin. It was found during this research that several components were found that had their biological activities described and proven, however, some major compounds described here had not been previously reported for A. virgata. These compounds may be further isolated and tested for their biological activities.