Two New Withanolides from the Aerial Parts of Datura innoxia

Abstract

Two new steroidal lactones of the withanolide group named as withametelinol (1a) and withametelinone (2) have been isolated from the aerial parts of Datura innoxia along with withametelin. The structures of the new constituents have been established as (20R,22R)-21,24-epoxy-12α-hydroxy-1-oxowitha-2,5,25(27)-trienolide and (20R,22R)-21,24-epoxy-1,12-dioxowitha-2,5,25(27)-trienolide through spectroscopic studies including one- and two-dimensional (COSY-45, NOESY, HMQC, HMBC) n.m.r. spectroscopy and chemical transformations.