Iridoid glycosides and lignans from the fruits of Gardenia jasminoides Eills

Four previously undescribed iridoid glycosides, including two bis-iridoid glycosides, and three undescribed lignans, together with 16 known analogues, were isolated from the fruits of Gardenia jasminoides Eills. Their structures were elucidated on basis of spectroscopic methods, and the absolute configurations of three of the unknown compounds were determined by interpretation of their electronic circular dichroic (ECD) and [α]20D data. The α-glucosidase inhibitory effects of the isolated compounds were evaluated and all the compounds exhibited slightly inhibitory activity with the values of IC50 greater than 50 μM.