Five flavonoids from the stems of Mangifera reba and their -glucosidase inhibitory activity

Abstract

Mangifera reba (Mangifera), belonging to the Anacardiaceae family, grows mainly in tropical and subtropical countries such as India, Vietnam, Malaysia and Thailand. Its chemical constituents are triterpenoids, flavonoids, xanthones, benzophenones and polyphenols. Previous studies presented that Mangifera reba contained abundant biological activities such as antibacterial, antioxidant and cytotoxic activity against breast cancer cell line MCF-7. However, research and databases in Vietnam are little available for this species. This paper presented the chemical constituents from the stems of Mangifera reba to provide more information to the database on medical plants in Vietnam. By using silica gel column chromatography and preparative TLC, eluting with organic solvents of different polarity, the ethyl acetate extract from the stems of Mangifera reba, collected from Dong Nai province in 2014, five flavonoids (−)-naringenin (1), (−)-eriodictyol (2), (+)-taxifolin (3), kaempferol (4) and quercetin (5) were isolated. The chemical structures of these compounds were elucidated based on the MS, NMR spectroscopic analysis and comparison with the literature. All 5 isolated compounds with IC50 values of 4.3−84.9 μM showed more potential inhibitory activity than the positive control acarbose (IC50, 214.5 μM).