New prenylhydroquinone glycosides from Phagnalon rupestre.
Three new hydroquinone glycosides were isolated from the MeOH extract of the aerial parts of Phagnalon rupestre. Their structures were elucidated as 1-O-beta-glucopyranosyl-1,4-dihydroxy-2-(3',3'-dimethylallyl)benzene (1), 1-O-beta-glucopyranosyl-1,4-dihydroxy-2-(3'-hydroxymethyl-3'-methylallyl)benzene (2), and 1-O-(4' '-O-caffeoyl)-beta-glucopyranosyl-1,4-dihydroxy-2-(3',3'-dimethylallyl)benzene (3) by spectroscopic methods.