Metabólitos especiais isolados de Eugenia copacabanensis Kiaersk (Myrtaceae) e avaliação de atividades antioxidante e antimicrobiana

Abstract

The genus Eugenia (Myrtaceae) comprises about 550 species of trees and shrubs, mainly found in Central and South America. Several species are used in folk medicine to treat diseases such as diabetes, chronic diarrhea, body aches, skin rash, etc. This has motivated diverse studies related to both the chemical composition and the biological properties of the genus. The objective of this work was to study the chemical profile of the species Eugenia copacabanensis, besides evaluating its antioxidant and atimicrobiano potential. The compounds described in this work were isolated from chromatographic techniques and identified by 1H and 13C NMR, GC-MS experiments besides comparison with literature data. From leaves of E. copacabanenis were isolated and -amyrin, ursolic acid, 30-hydroxy-ursolic acid (rubifólico), betulin, -sitosterol, -sitosterol glycoside, clovanodiol, globulol, viridiflorol and the flavonoids kaempferol-3-O-ramnosideo, quercetin-3-O-arabinoside, and quercetin. While from branches were isolated, friedelin, friedelan-3,4-lactone, taraxerol, octacosanyl coumarate, heptacosanyl coumarate, hexacosanyl coumarate and teracosanyl coumarate. From acetylation and methylation reactions of acid 30-hydroxy-ursolic it were obtained: diacetyl rubifolic acid methyl diacetyl rubifolato respectively. The antioxidant activity of the extracts and fractions was evaluated by DPPH and -carotene-linoleic acid methods. In both cases, we obtained excellent results with EC50 values ranging between 0.92 ±0.04 and 40.7 ± 1.0 g/ml and % inhibition between 28.7 ±7.9 to 90.0 ± 0.1%. Antimicrobial activity was evaluated against the microorganisms, Staphylococcus aureus, Candida albicans, Cryptococcus neoformans and Rhizopus oryzae and extracts and fractions of E. copacabanensis were not active until the concentration of 2.5 mg / mL.