Buxubodines E–G: three new triterpenoidal alkaloids from Buxus bodinieri and their cardioprotective activity

Three new triterpenoidal alkaloids, buxubodines E–G (1–3), along with two known analogues, were isolated from the methanol extract of the leaves and twigs of Buxus bodinieri. Their structures, all featuring a 6/7/6/5 tetracyclic skeleton, were elucidated through comprehensive spectroscopic analysis, including 1D and 2D NMR (1H-1H COSY, HSQC, HMBC, and NOESY) and HRESIMS data. In bioassays of the new isolates, compound 2 demonstrated more potent protective effects against doxorubicin-induced injury in H9C2 cardiomyocytes compared with the positive control cyclovirobuxinum D.