Chemical constituents of Ajuga forrestii and their anti-ferroptosis activity

Six new neoclerodane diterpenoids (1-6), along with ten known compounds (7-16), were isolated from Ajuga forrestii. Their structures were elucidated by HRESIMS, 1D and 2D NMR, ECD calculation, and single-crystal X-ray diffraction analysis. The structure of a known neoclerodane diterpene ajudecunoid C (6) was revised based on the reported NMR empirical rules. All the isolates were evaluated for their inhibitory effect on RSL3-induced ferroptosis in HT22 mouse hippocampal neuronal cells. Among them, compounds 8, 9, and 12 significantly inhibited RSL3-induced ferroptosis with EC50 values of 0.45 mu M, 0.076 mu M, and 0.14 mu M.

Automated summary

Six new neoclerodane diterpenoids and ten known compounds were isolated from Ajuga forrestii. Their structures were determined by various analytical techniques. The structure of a known compound was revised based on NMR empirical rules. The compounds were evaluated for their inhibitory effect on RSL3-induced ferroptosis, and compounds 8, 9, and 12 showed significant inhibitory activity.