Cytotoxic Diterpenoids from Isodon adenolomus.

Abstract: Aim: To study the chemical constituents of the aerial parts of Isodon adennolmus collected in the Shangrila region of Yunnan Province, China. Method: Compounds 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. Results: One ent-abietane, two abietane, and seven ent-kaurane diterpenoids were isolated and identified. Conclusion: Compounds 1–3 are new diterpenoids. Compounds 2–4 and 10 showed moderate inhibitory effects on several of the five tumor cell lines. [Copyright &y& Elsevier]