IRIDOID GLYCOSIDES OF Verbascum saccatum

Article abstract of DOI:10.1007/BF00579957

An aqueous solution of a methanolic extract of the epigeal part of Verbascum saccatum C.Koch (1.4 kg) was washed with organic solvents and chromatographed on columns of alumina, polyamide, and silica gel, leading to the isolation of 3.6 g of a new iridoid glycoside - saccatoside (I) - in the form of an amorphous substance with <α>²⁰_D -200 +/- 2.5 deg (c 0.2; methanol).The structure of (I), corresponding to 6-O-(2''-p-coumaroyl-α-L-rhamnopyranosyl)catalpol, was shown on the basis of the spectral characteristics of (I) and of its octaacetyl derivative (II) (mp 99 deg C, <α>²⁰_D -150 +/- 2.5 deg) and alkaline hydrolysis to 6-O-α-L-rhamnopyranosylcatalpol (III).In addition to (I), aucubin and (III) were detected chromatographically in the iridoid fraction.Details of the IR, NMR, and 13C spectra of (I) and (II) and of the mass spectrum of (II) are given.