Prospecção química e farmacológica do extrato obtido das folhas de Pseudobombax simplicifolium A. Robyns (MALVACEAE)

Abstract

Plants of the genus Pseudobombax, belonging to the Malvaceae family, have wide application in folk medicine and are known for their anti-inflammatory, antinociceptive, antioxidant, antimicrobial and anticancer activities. The present study aimed to investigate the physical-chemical characteristics, the chemical composition and the biological activity of Pseudobombax simplicifolium A. Robyns, a species with indication for popular medicinal use. Initially, the plant drug from the leaves of P. simplicifolium (DVF-PS) was subjected to a physical-chemical characterization test using official methods (particle size, moisture, ash, pH and density). The hydroalcoholic extract of the leaves of P. simplicifolium (EHF-PS) was submitted to qualitative and quantitative phytochemical analysis, as well as the evaluation of antioxidant and antimicrobial activities. The vegetable drug from the leaves showed granulometry, moisture, ash, pH and density, which are in accordance with the data recommended in the Brazilian Pharmacopeia. Such characteristics confirmed the preliminary analyzes of sizing, ash content and moisture. Phytochemical screening showed positive results for alkaloids, steroids and triterpenes. Quantitative analysis for steroids, triterpenes showed a high percentage and a low percentage for flavonoids attested the presence of these classes of metabolites in the extract of P. simplicifolium; The chemical investigation of the hydroalcoholic extract of the leaves was carried out using classical chromatography techniques such as: column chromatography (CC) and analytical thin layer chromatography (CCDA), and resulted in the isolation of two substances coded for PSF-01 and PSF-02. The structures of the substances were elucidated based on the data of nuclear Magnetic Resonance - 1H and 13C NMR. The analysis of 1H and 13C NMR data compared to data in the literature allowed the identification of the substances PSF-01 and PSF-02 as the triterpenes lupeol and betulin, respectively. The EHF-PS extract proved to be active for the tested methods (DPPH, ABTS) and was inactive compared to the CAT method. Among the evaluated methods, the best antioxidant activity of the extracts was for DPPH and ABTS compared to the trolox standard, however, did not exhibit antimicrobial activity against the Stafhylococcus aureus strain, indicating the possibility of testing with other strains.