Indoloquinazoline alkaloids from Euodia rutaecarpa and their cytotoxic activities.

Nine indoloquinazoline alkaloids (1-9) were isolated from the dried and nearly ripe fruits of Euodia rutaecarpa (Juss.) Benth. (Euodiae Fructus), along with limonin and β-sitosterol. Their structures were elucidated on the basis of their spectroscopic data. Among them, compounds 1 and 2 were new compounds and characterized as (7R,8S)-7-hydroxy-8-methoxy-rutaecarpine and (7R,8S)-7-hydroxy-8-ethoxy-rutaecarpine, respectively, and 1-hydroxy-rutaecarpine (3) and (7R,8S)-7,8-dihydroxy-rutaecarpine (4) were isolated from Euodiae Fructus for the first time. The nine indoloquinazoline alkaloids were evaluated for their cytotoxic activities against human promyelocytic leukemia HL-60 cells and human gastric carcinoma N-87 cells.