Four new alkaloids, 6,6a-dehydronorlaureline ({A figure is presented}), isosevanine ({A figure is presented}), isouvariopsine ({A figure is presented}), and O-methylcinnamolaurine ({A figure is presented}) have been isolated fron H. angustifolia, and their structures have been determined. The plant also contains the known aporphines corydine ({A figure is presented}), laurotetanine ({A figure is presented}), boldine ({A figure is presented}), glaucine ({A figure is presented}), and laureline ({A figure is presented}). © 1987.