Cytisine-like alkaloids from the seeds of Ormosia hosiei Hemsl. et Wils

Two new cytisine-like alkaloids, hositisines C (1) and D (2), were isolated from the seeds of Ormosia hosiei along with four known compounds, (-)-tinctorine (3), β-adenosine (4), 2′-deoxyadenosine (5), and 7, 2′, 4′-trihydroxy-5-methoxyisoflavanone (6). Their structures were established using extensive spectroscopic techniques (UV, IR, CD, HRESIMS, 1 D and 2 D NMR). In the cytotoxic activity, compounds 1–3 and 5-fluorouracil (positive control) displayed inhibitory effects against HepG2 cells, exhibiting IC₅₀ values of 44.52 ± 7.83 μM, 111.49 ± 12.76 μM, 127.72 ± 18.67 μM, and 16.37 ± 3.82 μM.