Cytotoxic Diterpenoids from Isodon adenolomus

AimTo study the chemical constituents of the aerial parts of Isodon adennolmus collected in the Shangrila region of Yunnan Province, China.MethodCompounds 1–10 were separated and purified by silica gel and C18 reversed phase silica gel column chromatography. The structures were elucidated by extensive spectroscopic methods (IR, UV, MS and NMR), and the absolute configuration of 1 was determined by single crystal X-ray diffraction analysis. Compounds 2–5 and 10 were evaluated for their in vitro cytotoxicity against human tumor cell lines, HL-60, SMMC-7721, A-549, MCF-7, and SW-480.ResultsOne ent-abietane, two abietane, and seven ent-kaurane diterpenoids were isolated and identified.ConclusionCompounds 1–3 are new diterpenoids. Compounds 2–4 and 10 showed moderate inhibitory effects on several of the five tumor cell lines.