Phenylethanoid glycosides from Digitalis ferruginea subsp. ferruginea (=D. aurea Lindley) (Scrophulariaceae)

Abstract

Two new phenylethanoid glycosides, ferruginoside A (3,4-dihydroxy-β- phenylethoxy-O-β-D-glucopyranosyl(1→6)-2-O-caffeoyl-β-D-glucopyranoside) and ferruginoside B (3,4-dihydroxy-β-phenylethoxy-O-β-D-glucopyranosyl- (1→+6)-β-D-glucopyranoside) were isolated, along with the known compounds lugrandoside and transferulic acid, from the aerial parts of D. ferruginea subsp. ferruginea. For structural elucidation of the isolates, chemical transformation (acetylation, methylation, alkaline hydrolysis), one and two dimensional (COSY, HMQC, HMBC, ROESY) NMR techniques and FAB-MS were used.