The stem bark of Luvunga angustifolia yielded a new acridone alkaloid, 5-methoxyarborinine [1), and several known compounds. Several known compounds were also isolated from Limonia acidissima. Pleiospermium alatum afforded a rare coumarin glycoside, apiosylskimmin [5], and two known limonoids 6 and 7. Nmr studies of 6 demonstrated strong nOe effects due to ''through-space'' coupling and led to revision of some previous carbon signal assignments. A probable biosynthetic relationship between some limonoids of the Rutaceae is suggested.