Two alkaloids, named Chinese bittersweet alkaloid I and II, were isolated from the seeds of Chinese bittersweet (Celastrus angulatus M.). Their structures were identified as (-)-2 alpha-(2'-pyrrolyl)-4 alpha-methoxycarbonyl-1,3-oxazacyclohexane and 2 alpha-(2'-pyrrolyl)-4 alpha-methoxycarbonyl-5 beta-[(2-methyl)-heptyl]-1,3-oxazacyclohexane, respectively, by spectroscopic methods. (C) 1999 Elsevier Science Ltd. All rights reserved.