Trigoxyphins A-G: Diterpenes from Trigonostemon xyphophylloides

Six new oxygenated daphnane-type diterpenoids, trigoxyphins A-F (1-6), a phenanthrene-type diterpenoid, trigoxyphin G (7), and two known compounds were isolated from twigs of Trigonostemon xphophylloides. Their structures were established using spectroscopic methods. Compounds 1 and 2 exhibited strong cytotoxic activity against HL60 (IC(50): 0.27 and 0.49 mu M) and A549 (IC(50): 7.5 and 4.9 mu M) tumor cell lines, respectively.