Structure elucidation of cordifolin A, a novel cucurbitacin from Fevillea cordifolia, using one and two dimensional n.m.r. techniques

Abstract

Cordifolin A (3)[3β,16α-dihydroxy-20,25-epoxy-19(10 → 9β)-abeo-10α-lanost-5-en-11,22-dione] was isolated from the methanol-soluble fraction of the 1% tartaric acid extract of dried seeds of Fevillea cordifolia L. (Cucurbitaceae) used in Jamaican folk medicine. Structure elucidation was based primarily on the use of multi-pulse n.m.r. techniques, especially combination of long range and direct ¹H,¹H INADEQUATE and ¹H, ¹³C chemical shift correlation spectra. Biosynthesis of this novel triterpene apparently involves cyclization of the side chain to give a six-membered ether ring which is unprecedented among cucurbitacins.