Estudo químico e avaliação das atividades biológicas de Eugenia pruniformis cambess (Myrtaceae)

Abstract

Brazil is one of the countries with the greatest biodiversity in the world. The Myrtaceae family is one of the most representative of native Brazilian species. In Espírito Santo 52 species are found in the restinga vegetation regions inserted in the municipalities of Conceição da Barra and São Mateus. Among those is found Eugenia pruniformis, popularly known as azeitoninha da praia. Studies on its chemical composition and biological activities are still scarce. The present work’s main objective was to assess the chemical profile and activities that could act as antioxidant, thrombolytic and to inhibit α-glycosidase, α-amylase and tyrosinase enzymes that occur in the ethanolic extract from the leaves of E. pruniformis. The chemical profile was assessed through the fulfilment of a preliminary phytochemical prospection, major chemical classes quantification and the usual techniques of fractioning and purification. For biomonitoring of biological activities, the ethanolic extract of the leaves of E. pruniformis (EEPP) was subjected to the partition process to obtain the ethyl acetate (FAcetEP) and aqueous (FAEP) fractions. The antioxidant capability was measured compared to synthetical radical’s DPPH and ABTS. The thrombolytic activity assessed the extract’s capability to promote clot lysis. The inhibition activities of the α-amylase, α-glycosidase and tyrosinase enzymes were measured using spectrometric methods. The EEEP preliminary phytochemical analysis indicated presence of flavonoids, alkaloids, tannins, coumarins and steroids. Some fractions obtained were subjected to analysis by CG-MS and were identified: Caryophylline oxide, Globulol, Spatulenol, δ-Cadinol, α-Eudesmol, β-Eudesmol, γ-Muurolene, Cadina-1,3,5-triene, Caryophylene , α-Selinene, Friedelina, Cholesta-4-6-dieno-3-ol, (3β), Stigmasta-3,5-diene-7-one and γ-Sitosterol. Using a one-dimensional NMR technique, the α-amyrine, β-amyrine, α-amyrine acetate, β-amyrine acetate and β-sitosterol were identified. As a result of biological activities, EEEP promoted 14.41% of clot lysis while the streptokinase pattern showed 50.12%. For the evaluation of the capture activity of the radical ABTS, EEPP, FAcetEP and FAEP demonstrated EC50 of 2.71, 1.78 and 11.88 µg/ mL, respectively, while the TROLOX standard presented EC50 of 0.79 µg/mL. For the EEEP, FacetEP and FAEP α-glycosidase inhibition assay, presented EC50 of 20.69, 14.35 and 2.79 µg/mL, respectively, while the positive control Acarbose demonstrated EC50 of 1607 µg/mL. And for the assay on α-amylase EEEP and FAEP presented EC50 of 6.92 and 5.53 µg/mL respectively and the positive control Acarbose showed EC50 of 1.41 µg/mL. It can be seen that Eugenia pruniformis and its fractions showed antioxidant and promising inhibitory activity against the enzymes α-glycosidase and α-amylase. The present work reported, for the first time, chemical and biological aspects of this species, leading new investigations to elucidate the mechanisms of action involved by the biological activities performed.