C‐Ring Aromatized Abietane Diterpenoids from Lycopus lucidus

The phytochemical research of the extract of Lycopus lucidus, led to twelve aromatic C‐ring abietane diterpenoids (1‐12), including three new structures (1‐3) obtained. The structures including absolute configurations of the new compounds were elucidated via HRESIMS, NMR, combined with the ECD calculations. Among them, compound 1 is a rare 17‐norditerpenoid, and compound 2 is a 19‐norditerpenoid. Moreover, compound 3 is a rearranged 18(4→3)‐abeo‐abietane diterpenoid. The bioassay results showed that new compound 3 exhibited potential cytotoxicity on HEL cells, with an IC50 value of 14.59 ± 0.55 μM. Besides, compound 9 showed remarkable cytotoxicity against HEL cells, with the IC50 value of 0.93 ± 0.11 μM (Stronger than that of the positive control, doxorubicin, IC50 = 0.95 ± 0.12 μM). Furthermore, the flow cytometry revealed that compound 9 exerts anti‐tumor effect should be relation to induce HEL cells apoptosis.