Diterpenoids from the bark of Torreya grandis and their cytotoxicity activity

Four previously undescribed diterpenoids (2-5) were isolated from the bark of Torreya grandis, along with ten known analogues. The structures of the compounds were elucidated using NMR, HR-ESIMS, and ECD calculation. The cytotoxic effects of the isolated compounds on HCT-116, AsPC-1, and HepG2 cells were evaluated using the MTT assay. Compound 6 exhibited significant cytotoxicity against HepG2 cells. Further experiments revealed that compound 6 could arrest the G2 phase process in HepG2 cells through the JAK2/STAT3 signaling pathway.