N-Substituted acridone alkaloids from Toddaliopsis bremekampii (Rutaceae: Toddalioideae) of south-central Africa.

Toddaliopsins A-D, four novel 1,2,3-trioxygenated acridone alkaloids, have been isolated from the leaves of Toddaliopsis bremekampii. Toddaliopsins B-D are the first reported acridone alkaloids with substituted N-methyl groups, in the light of which the chemotaxonomic relationship of Toddaliopsis and Vepris is discussed. Toddaliopsin C possesses moderate anti-inflammatory activity, which may be related to the hydroxy group present at C-1.