LAUSR

Abstract The chemical investigation of whole plants Euphorbia stracheyi Boiss from China led to the isolation of one new ent-kaurane diterpene, ent-Kaurane-16β,17,19-triol-3-one (1), along with three known ent-kaurane diterpenoids (2–4) as ent-Kaurane-3α,16β,17-triol (2)，ent-16S,17-dihydroxy-kaurane-3-one (3) and ent-3S,16S,17-trihydroxy-kaurane-2-one (4). Their structures were elucidated by extensive spectroscopic analyses including 1D, 2D NMR, HR-ESI-MS, and by comparison with the literature. Compound 2 was a new natural product and firstly isolated from nature, while compounds (3–4) were isolated from E. stracheyi for the first time. All isolated compounds (1–4) were evaluated for their cytotoxic activities against five human cancer cell lines (including A-549, SMMC-7721, HL-60, MCF-7 and SW-480). Graphical Abstract