Cytotoxic diterpenoids were enriched and orientation prepared from the aerial parts of Isodon excisoides target-guided by UPLC-LTQ-Orbitrap-MS. Four diterpenoids were obtained, including a novel compound: 1α-acetoxy-7α, 14β, 20α-trihydroxy-ent-kaur-16-en-15-one (1); together with three known compounds kamebakaurin (2), lasiokaurin (3), enmenol-1-β-glucoside (4). Their structures were elucidated on the basis of spectroscopic methods in conjunction with published data for their analogues. All compounds were tested for their cytotoxic effects against five human cancer cell lines HCT-116, HepG2, A2780, NCI-H1650 and BGC-823, respectively. Compounds 1 and 2 showed obviously cytotoxic activity against the five cancer cell lines with IC50 ranging from 1.06 to 3.60 μM. Compounds 3 and 4 showed selective cytotoxic activity.
Keywords: Isodon excisoides; cytotoxic activity; diterpenoid; orientational preparation.