New Compounds from the Roots and Stems ofTrigonostemon liiand Their Cytotoxic Activities

A new carboline alkaloid, Trifiline D (1) and a new degraded diterpenoid, Trigoxyphin X (4) were isolated from the roots and stems of Trigonostemonlii. Their structures were elucidated by extensive spectroscopic analyses including 1D- and 2D-NMR techniques. Compound 1 exhibited weak inhibitory activity against MCF-7, A-549, MGC-803, and COLO-205 with IC50 values ranging from 27.4 to 35.4 mu M.