Three new sesquiterpenoid alkaloids, cangorin K (1), dimacroregelines C (2) and D (3), as well as two known sesquiterpenoids (4–5), were isolated from the roots of Tripterygium wilfordii Hook. f. The structures of new compounds were characterised by extensive 1D and 2D NMR spectroscopic analyses, as well as HRESIMS data, and the known compounds were established by 1 D NMR spectra referring to the literatures. Cytotoxicity evaluation of these compounds against two human tumour lines...