Some terpenoid compounds from the ethyl acetate extract of Annona muricata L. leaves and their α-glucosidase inhibitory activity

Abstract

Annona muricata L., a species from the Annonaceae family, known as “Mãng cầu xiêm” in Vietnam. It is an edible plant that contains a plethora of nutrition such as vitamins, fiber and mineral. Multiple researches about the chemical constituents of Annona muricata L. had been carried out across the world, from different parts such as the stems, leaves, fruits, and seeds and several compounds such as acetogenin, megastigmane, polyphenol, alkaloid, … had been isolated. Other researches about its biological activity also showed that Annona muricata L. had plenty of crucial biological activities including anti-inflammatory, anticancer, hypoglycemia, antioxidant and antibacterial. From the ethyl acetate extract of leaves’ s Annona muricata L., five compounds were isolated, including three megastigmanes (1−3) and two acyclic diterpenoids (4−5). Using one-dimension and two-dimension NMR, high resolution mass spectrometric analysis and comparing to the corresponding data in the literature, the chemical structure of the isolated compounds were elucidated as dehydrovomifoliol (1), vomifoliol (2), vomifoliol acetate (3), trans-phytol (4) and 1-O-acetylphytol (5). Except 2, the four remaining compounds have not been reported in the plant. All the five compounds were tested for their inhibitory activity against enzyme α-glucosidase, compounds 1, 3 and 4 showed moderate α-glucosidase inhibitory effect with the IC50 values of 45−210 µM, compared to the positive control acarbose (IC50 214.5 µM).