New neo-clerodane diterpenoids from Scutellaria strigillosa with cytotoxic activities.

AbstractTwo new neo-clerodane diterpenoids, named scutestrigillosins D and E (1 and 2), were isolated from the whole plant Scutellaria strigillosa. Their structures were established on the basis of detailed physical data analyses. In vitro, two new compounds exhibited cytotoxic activities against four tumor cell lines (HONE-1, P-388, MCF7, and HT29), and gave IC50 values in the range of 3.4–8.9 μΜ.