Four steroidal alkaloids from the leaves of Buxus sempervirens

Four new steroidal alkaloids, N-20-formylbuxaminol E [(20S)-16 alpha-hydroxy-20-(formylamino)-3 beta-(dimethylamino)-9,10-secobuxa- 9(11),10(19)-diene] (1), O-16-syringylbuxaminol E [(20S)-16 alpha-syringoyl-3 beta-(dimethylamino)-20-(amino)-9,10-seco-buxa- 9(11),10(19)-diene] (2), N-20-acetylbuxamine G [(20S)-20-(acetylamino)-3 beta-(methylamino)-9, 10-seco-buxa-9(11),10(19)-diene] (3) and N-20-acetylbuxamine E [(20S)-20-(acetylamino)-3 beta-(dimethylamino)-9,10(19)-diene] (4) were isolated from the leaves of Buxus sempervirens. Their structures were determined mainly on the basis of 2D NMR studies. (C) 2000 Elsevier Science Ltd. All rights reserved.