ESTUDO FITOQUÍMICO COM FINS FARMACOLÓGICOS DE Pavonia glazioviana GÜRKE (MALVACEAE)

Abstract

Medicinal plants are used since 5000 thousand years in India, China and Egypt.Phytochemical analyzes are performed in order to determine or quantify the presence of plant secondary metabolites. These substances are capable of interacting in biological systems and studies seek their application as antimicrobial, anesthetic and antiviral compounds. Phenolic compounds, form several classes of secondary metabolites, and demonstrate benefits to human health, evidencing the reduction of cancers and reduction of serum cholesterol, due to its antioxidant activity of vegetables. Some species of the Pavonia genus stand out with reports of antifungal and antibacterial activity. The focused specie of this work is the Pavonia glazioviana Gürke, known as "malva-da-chapada" and "capa- cabaça". The present work aims to perform the phytochemical study of P. glazioviana, considering its pharmacological potential. The preliminary phytochemical analysis was developed according to Matos (1997) through characteristic reactions for the plant metabolites. The total phenolic content of the sample was determined using the Folin-Ciocalteau spectrophotometric method. To evaluate the antioxidant activity, the method offree radical DPPH (2,2-diphenyl-1-picrylhydrazyl) was used. The isolation and identification ofthe chemical constituent was carried out using cromatoghraphy followed by NMR. The ethanolic extract of P. glazioviana showed a positive result for the following secondary metabolites: flavonoids, alkaloids, coumarins, tannins, steroids and triterpenes. In the ethanolic extract of the studied species were found48.20 ± 1.713 mg of EAG / g of ethanolic extract. In the evaluation of the antioxidant activity the EC50 found was 6.36 mg / mL ± 0.02921. The results indicate that the species is a producer of high content of phenolic substances and presents interesting antioxidant activity. The antioxidant activity may indicate beneficial action against various types of cancer and chronic diseases associated with the oxidation process of biomolecules. It was possible to isolate and identify the flavonoid 5,7-dihydroxy-3,8,4'-trimethoxyflavone, reported for the first time in the genus Pavonia, contributing to the chemotaxonomy of the Malvaceae family. The results found are of great importance for the study of this species, as well as for its contribution to human health.