Chemical study and evaluation of antioxidant activity and α-glucosidase inhibition of Myrciaria strigipes O. Berg (Myrtaceae)

Abstract

Myrciaria strigipes O. Berg (Myrtaceae) is a Brazilian native species, endemic to Bahia and Espírito Santo, and known popularly as "cambucá da praia". This study aimed to evaluate the chemical profile of ethanol extract of leaves from M. strigipes (EEF), and the two in vitro activities: antioxidant and inhibition of α-glucosidase. The column chromatography separation gave friedelin (1), glutinol (2), β-sitosterol (3), 28-hydroxyfriedelin (4), and ursolic acid (5). The chromatographic profile of EEF by HPLC (354 nm) allowed the identification of three phenolic compounds: ellagic acid (6), hyperoside (7), and isoquercitrin (8). The extract EEF showed antioxidant activity in both models DPPH and ABTS, with EC50 of 61.79 ± 2.97 and 23.72 ± 0.48 μg/mL, respectively. Trolox, used as a standard, showed EC50 of 4.60 ± 0.82 and 1.08 ± 0.05 μg/mL, respectively. The obtained result of the inhibition assay on the enzyme activity of α-glucosidase revealed that EEF had an EC50 value of 40.66 ± 0.81 μg/mL, close to the positive standard deoxynojirimycin (EC50 = 37.30 ± 4.41 μg/mL). Therefore, this study contributed to the knowledge of the chemical and biological properties of M. strigipes and will subsidize future studies of this species.