Perfil químico e atividades biológicas dos frutos de Vismia spp

Abstract

Species of the genus Vismia are popularly known as pau-de-seal or lacre. They are distributed in tropical regions such as Colombia, Venezuela and Brazil. Among the biological activities of Vismia species, the great therapeutic value stands out as antifungal, antitumor, larvicidal, leishmanicidal, anti-inflammatory, among other activities. Therefore, the objective of this research was to evaluate the chemical profile of the fruit extracts of the species Vismia guianensis and Vismia cayennensis and to synthesize by Cu(II) coordination the isolates of the fruits of these species, in addition to evaluating their activities regarding their antioxidant, antimicrobial capacity, antileishmania in vitro and quantification of total phenols. The fruits were macerated to obtain the resin present in these species. Extractions were performed during a period of 7 days with a 70% hydroalcoholic solution. The extracts obtained were coded as EVC (V. cayennensis) and EVG (V. guianensis). After sequential extraction procedures with organic solvents, the following extracts were obtained: hexane (EHVC, EHVG), dichloromethane (EDVC, EDVG), ethyl acetate (EAVC, EAVG) and methanol (EMVC and EMVG). The extracts were evaluated for their antioxidant capacity against DPPH and ABTS radicals, the total phenolic content was obtained spectrophotometrically according to the Folin-Ciocalteu method. In the antimicrobial activity, the agar diffusion method was used against Staphylococcus aureus, Streptpcoccus pneumoniae, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Burkholderia cepacia, Serratia marcescens and Mycobacterium smegmatis. Samples were evaluated for anti-leishmanial activity, in vitro, against promastigotes of Leishmania (Leishmania) amazonensis and Leishmania (Leishmania) guyanensis within 72 hours. The EDVC, EDVG, EHVC and EHVG extracts underwent the silica column chromatography technique and the fractions analyzed by HPLC/UV and APCI/MS in order to identify the constituents. The 1H NMR technique was used to identify isolated constituents. From the isolated constituents it was possible to synthesize the compounds of catechin and quercetin in a mixture of methanol added in the methanolic solution of CuSO4·5H2O. Through the results it was possible to isolate and identify the phenolics catechin, quercetin and fiscion, from these two complexes were synthesized, catechin (CAT-cp) and quercetin (QUER-cp). Through the technique of NMR it was possible to identify the anthraquinone fissiones. From the biological assays, significant antioxidant activity of the hydroalcoholic extracts against DPPH and ABTS radicals was observed, as well as a high antioxidant capacity of the flavonoids quercetin and catechin. The metal complex synthesized quercetin showed a greater capacity to capture the DPPH radical with an IC50 of 1787.6µM. In the antimicrobial activity, low activity was identified for the EHVC sample against the bacteria E. faecalis. For the antileishmania evaluation, the EVC extract showed the best IC50 (74.39µg.mL) during 48 hours for L. amazonensis and the quercetin complex showed the best activity against L. guyanensis (78.66µg.mL). Given the results obtained, it was possible to prove the biological potential of the two species selected for this study, in addition to proving a greater biological potential of the synthesized complexes from V. cayennensis and V. guianensis. The continuity of this study is necessary for a better elucidation of the anti-leishmanial potential of the metallic complexes obtained (QUER-cp and CAT-cp).