Estudo fotoquímico, antioxidante e da atividade biológica de constituintes do resíduo madeireiro e da seiva de Hymenaea courbaril

Abstract

The Fabaceae family is widely distributed which Hymenaea courbaril is one of the most important species. Because of its multiple use, ethnopharmacological and pharmacological potential, it is crucial to investigate its chemical constitution and bioactive compounds. In this study, we aimed to perform the phytochemical analysis, antioxidant and antimicrobial activity of the sap and ethanolic extract of H. courbaril wood residues. The forest residues and sap were obtained from the Fortimber forestry company, near the city of Santarém, Pará, Brazil. To obtain the extract, the sawdust was dried in an oven at 40°C for 96 hours, for subsequent extraction of secondary metabolites with the solvent ethanol in a Soxhlet apparatus. The following techniques were performed to complete phytochemical analysis: Thin Layer Chromatography (TLC), Gas Chromatography coupled to Mass Spectrometry (GC-MS), High Performance Liquid Chromatography coupled to a photo-diode array detector (HPLC-PDA), High Performance Liquid Chromatography coupled to a Mass Spectrometer (HPLC-ESI MS/MS), using the molecular interaction networks approach or molecular networking through the GNPS (Global Natural Products Social Molecular Networking) platform. One and two dimensional Nuclear Magnetic Resonance technique, (1H, 13C, HMBC, HSQC) was used for the identification of the isolated substances. The antioxidant activity (DPPH and FRAP), quantification of total flavonoids, phenolic compounds contents were done by spectrophotometric methods. The antimicrobial activity of both extract and sap of H. courbaril were performed against microorganisms of clinical interest by the minimum inhibitory concentration (MIC) technique. The ethanolic extract has a higher antioxidant potential and has the highest content of phenolic compounds and flavonoids when compared to the sap. The predominant compound class in both the extract and the sap are flavonoids, which enabled identification of 16 substances including taxifolin derivatives through spectral correspondence with experimental data from GNPS. Through analysis of the 1D and 2D NMR spectra it was possible to identify the substances fustin, taxifolin, 3-methoxy-quercetin and quercetin. The ethanolic extract stood out in relation to the sap by showing greater antimicrobial activity in vitro. The substance taxifolin, isolated by NMR, had less biological potential when compared to the results obtained from the ethanolic extract. From these data, it is possible to contribute to the safe use of H. courbaril, by traditional populations in the Amazon, for the preparation of herbal medicines and formulations.