Two new cytotoxic canthin-6-ones, 10-methoxycanthin-6-one (1) and 10-hydroxycanthin-6-one (2) were isolated from the wood of Simaba multiflora (Simaroubaceae). Three canthin-2,6-dione (3), 3-methoxycanthin-2,6-dione (4) and canthin-2,6-dione (5), as well as scopoletin (7) and the novel coumarino-lignan cleomiscosin A (6) were also obtained.