New Alkaloids from Hippeastrum papilio (Ravenna) Van Scheepen

Abstract

A new phytochemical study of the indigenous Brazilian species Hippeastrum papilio is reported herein. Three novel Amaryllidaceae alkaloids were isolated, including hippapiline (1), papiline (2), and 3-O-demethyl-3-O-(3-hydroxybutanoyl)haemanthamine (3). Their structures were determined by physical and spectroscopic methods. In addition, the known alkaloids, haemanthamine (4), galanthamine (5), narwedine (6), 11β-hydroxygalanthamine (7), apogalanthamine (8), and 9-O-demethyllycosinine B (9) were identified. The unusual cis-B/C-ring fusion for the new homolycorine representative hippapiline was ratified by NMR and CD spectroscopy.