6,7-seco-ent-Kaurane diterpenoids from lsodon sculponeatus and their bioactivity

One new 6,7-seco-ent-kaurane diterpenoid, sculponin T (1), was isolated from the aerial parts of Isodon sculponeatus, along with four known analogs, sculponeatin J (2), sculponeatin K (3), sculponeatin C (4), and sculponeatin Q (5). Their structures were elucidated by extensive spectroscopic analysis and by comparison with data reported in the literature. Significant cytotoxic activity was observed for compound 2 against five human tumor cell lines with IC₅₀ values ranging from 1.8 μmol/L to 3.3 μmol/L, and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with IC₅₀ value of 3.3 μmol/L.