Pachysandra Alkaloids. VIII. Structures of Pachystermine-A and -B, Novel Type Alkaloids Having a β-Lactam Ring

Abstract

Pachystermine-A (I) and -B (II), weakly basic alkaloids isolated from Pachysandra terminalis SIEB. et ZUCC.(Buxaceae), were investigated. The structures and stereochemistry of these alkaloids are now assigned to the formula I and II, respectively. They represent a novel type of 3, 20-diamino-5α-pregnane alkaloid carrying a four-membered β-lactam ring system.