Three adducts of butenolide and apigenin glycoside from the leaves of Machilus japonica.

Chemical investigation of the EtOH extract of the leaves of Machilus japonica var. kusanoi resulted in the isolation of three compounds with a unique skeleton, i.e., apigenosylides A-C (4-6), together with five known flavonoid glycosides. Some of these compounds possess moderate inhibitory activity against alpha-glucosidase. The structures of the new compounds were elucidated on the basis of spectrometric analyses. They possess an unprecedented skeleton comprising the adduct of a butenolide moiety and apigenin glycoside linked via a 1,2-dioxane moiety.