Limonoids from the leaves and stems of Toona ciliata

Abstract

Three new norlimonoids, toonaciliatins A (1), F (6), and G (7), four new limonoids, toonaciliatins B-E (2-5), and five known compounds, 5alpha,6beta,8alpha-trihydroxy-28-norisotoonafolin (8), toonaciliatins H (9) and I (10), febrifugin (11), and khayasin T (12), were isolated from the leaves and stems of Toona ciliata. Compounds 1-3 have an unusual 1-en-3-one system with a 1,11-oxygen bridge, limonoids 11 and 12 have a mexicanolide-type structural frame, and others are typical A,B-seco- (4, 5, 9, and 10) or B-seco-29-nor- (3, 6, 7, and 8) limonoids. Toonaciliatins H (9) and I (10) were obtained for the first time as natural products. The structures were established by extensive spectroscopic methods, particularly 1D and 2D NMR techniques.