New sesquiterpenoids and a diterpenoid from Alpinia oxyphylla

Abstract

The new compounds 2-methyl-6-isopropyl-7-hydroxymethyl naphthalene (1),oxyphyllenone H (2), epi-oxyphyllenone (6), (E)-labda12,14dien-15(16)-olide-17-oicacid (3), and two new natural products 4 and 5 were isolated from the ethyl acetate part of95% ethanol extract of Alpinia oxyphylla, together with six known compounds 7-12. The inhibitory effects of compounds 1-12 on a-glucosidase were evaluated, and compounds 1, 3 and 6 showed moderate bioactive effect, with inhibitory rates of 10.3%, 10.0% and 11.5%,respectively, compared to the positive control acarbose (41.9%) at 20 g/mL.