The structure of procumbide

Abstract

A revised structure for procumbide (2), an iridoid glucoside from Harpagophytum procumbens, is proposed, based on ¹H and ¹³C n.m.r, spectral information and ¹H homonuclear Overhauser enhancements. The revised structure is an isomer of antirrhinoside, differing only in the stereochemistry at C6.