Phytochemical investigation on the 95% EtOH extract of the Traditional Chinese Medicine (TCM) Euphorbia royleana (Ba-wang-bian in Chinese) led to the isolation of 11 diterpenoids (1-11) and two triterpenoids (12 and 13). Among them, compounds 1 and 2 were new ingenane and ingol diterpenoids, respectively. Their structures were elucidated by a combination of spectroscopic analyses (1 D and 2 D NMR, HRMS, ECD, UV, and IR data) and chemical methods. Compounds 12 and 13 exhibited moderate cytotoxicities in vitro against human lung cancer cell line A549 with IC50 values of 14.84 ± 0.56 and 27.11 ± 1.65 µM, respectively.
Keywords: Euphorbia royleana; Euphorbiaceae; cytotoxicities; diterpenoids.