Isowilfordine: An alkaloid from Tripterygium wilfordii

A new alkaloid, C43H49NO19, isomeric with wilfordine, was isolated from root extracts of the insecticidal plant, Tripterygium wilfordii. Its structure was deduced from spectroscopic and degradative evidence. The new compound, designated isowilfordine, differs from the parent alkaloid in the substitution pattern of the nicotinic acid moiety.