Isopimarane-type diterpenoids from the rhizomes of Kaempferia galanga L. and their biological activities

Abstract

Fourteen isopimarane diterpenoids (1–14) were isolated from the rhizomes of Kaempferia galanga, including four new compounds (1–4). The isolated secondary metabolites were identified through analysis of spectroscopic (1 D and 2 D NMR) and mass spectrometric data, together with X-ray diffraction studies. Compounds 4–5, 7–11, and 13 showed strong antimalarial activities, with IC50 values in the range of 1.46–3.99 μg/mL. Moreover, compounds 4, 5, 8, and 12 showed cytotoxicity against KB cell line with IC50 values in the range of 6.13–38.2 μg/mL, while compounds 4, 5, and 12 showed cytotoxicity against MCF-7 cell line with IC50 values in the range of 11.75–47.4 μg/mL. Eventually, the isolated compounds were screened against six bacterial strains and Mycobacterium tuberculosis, demonstrating weak to moderate activities.