Cytotoxicent-Kaurane Diterpenoids fromIsodon nervosus

Abstract Four new ent ‐kaurane diterpenoids, rabdonervosins G–J ( 1 – 4 , resp.), were isolated from the leaves and stems of Isodon nervosus. Their structures were elucidated by extensive spectroscopic analyses, including 1D‐, 2D‐NMR and HR mass spectra. Compound 2 showed potent cytotoxicity against the HepG2 and PC‐9/ZD cell lines with IC 50 values of 2.36 and 6.07 μ M , respectively, and compound 3 exhibited cytotoxicity against the HepG2 and CNE2 cell lines with IC 50 values of 8.64 and 9.77 μ M , respectively.