Two new ent-kaurane diterpenoids from<i>Pteris semipinnata</i>

Abstract

In this study, two new compounds and six known compounds were isolated from the aerial parts of Pteris semipinnata. The chemical structures of these two new compounds were elucidated as 6β,11α-dihydroxy-15-oxo-ent-kaur-16-en-19-oic acid (1) and 7α,11α-dihydroxy-15-oxo-ent-kaur-16-en-19-oic acid (2) by the extensive spectral methods including 2D NMR and HR-MS techniques.