Two new alkaloids possessing the 1-phenylethyltetrahydroisoquinoline skeleton, dysoxyline (1) and S-(+)-homolaudanosine (2), have been isolated from Dysoxylum lenticellare Gillespie (family Meliaceae) along with known homoerythrina alkaloids 3-epischelhammericine (3) and 2,7-dihy. drohomoerysotrine (4). Also isolated was a new alkaloid with a novel dibenz[d,f]azecine skeleton, dysazecine (5). The macrocycle 5 represents the trapping of a biosynthetic intermediate in the postulated conversion of the phenylethylisoquinoline skeleton to the homoerythrina skeleton. None of these alkaloid skeleta have been found previously in plants of the Meliaceae. © 1983, American Chemical Society. All rights reserved.