Estudo fitoquímico e biológico das espécies Schinus lentiscifolius, Schinus terebenhtifolius, Schinus molle e Schinus polygamus (Anacardiaceae) do RS

Abstract

The phytochemical and biological study of the species S. lentiscifolius, S. terebinthifolius, S. molle and S. polygamus known as ―aroeiras‖ (Anacardeaceae) distributed in Rio Grande do Sul, was carried out to establish the chemical composition of volatile oils obtained by hydrodistillation of aerial parts of leaves, flowers and fruits collected in different seasons. In addition, leaves and fruits were analyzed and compared to determine seasonal variations in the oils constitution. The oils chemical composition was determined by Gas Chromatography coupled with a Mass Spectrometry (GC-MS). The yields of the studied species oils essential aerial parts ranged from 0.14-2-13%, depending on the stage of development and part collected. One hundred and thirty-five compounds were identified from the oils essential, representing approximately 90% of the oils from leaves, flowers and fruits collected between spring and summer in 2005 to 2011. The volatile oils of the analyzed species showed a constant qualitative standard in the compounds: α-pinene, β-pinene, δ-2- carene, limonene for majority monoterpenes; germacrene-D, bicyclogermacrene, δ-cadinene, spatulenol, caryophyllene oxide and -cadinol for majority sesquiterpenes in the leaves oil; α- pinene, mircene epi-cubenol, cubenol and spatulenol for majority sesquiterpenes in the flowers oil; α-pinene, β-pinene mircene, epi-cubenol, cubenol, spatulenol, caryophyllene oxide and -cadinol for majority sesquiterpenes in the oil fruits. The quantitative variations among the different constituents in oils of different species were quite relevant. Additionally, considering the therapeutic potential and the compounds described, the phytochemical study and antioxidant and antimicrobial activity were evaluated in the oils, crude extracts, aqueousextracts, isolated and derivative compounds. The aqueous extracts obtained by 9 hydrodestillation, in part were dried by lyophilization and in part were subjected to a liquidliquid partition using hexane solvent, ethyl acetate and n-butanol. Besides these, the crude extract was prepared from the leaves of S. lentiscifolius. The chromatographic fraction of crude extract and ethyl acetate led to the isolation and identification of nonadecanol (1) and moronic acid (2). From moronic acid (2) by employing NaBH4 reduction reaction were obtained the derivatives morolic acid (3) and 3-epi-morolic acid (4). The analysis of S. lentiscifolius ethyl acetate aqueous extract led to the isolation of the compound FLA-1 (5) and galic acid (6), from this was obtained the derivative methyl gallate (7). The S. molle nbutanol aqueous extract led to the isolation of the flavonoid quercetin (8) and rutin (9). The substances were identified by physical data and spectroscopic techniques (1H NMR, 13C, COSY, HMQC, HMBC), mass spectrometry and X-rays. The aqueous extracts analysis by High-Performance Liquid Chromatography (HPLC) led to the characterization of galic acid (6), quercetin (8) and rutin (9) comparing to the existing laboratory standards. All extracts present galic acid (6), except to S. molle. The oils antimicrobial activity of the species S. lentiscifolius, S. terebinthifolius, S. molle and S. polygamus were evaluated by microdilution method using a collection of pathogenic microorganisms composed of bacteria and fungi. The results showed that the obtained oils from different plants were active using the most of the microorganisms tested. Best results were found in the fruits oils of S. terebinthifolius. The extracts and fractions of S. lentiscifolius, S. terebinthifolius and S. molle have also been tested as antibacterial and antifungal activity. Best results were found for the extract of S. lentiscifolius with a Minimum Inhibitory Concentration (MIC) from 31.2 to 12.5 mg/mL. In addition, isolated compounds extracts were evaluated as antioxidant activity using 2,2-diphenyl-picrylhydrazyl (DPPH). All extracts and compounds tested showed inhibition results for free radical DPPH.