New eremophilanes from Farfugium japonicum

Eighteen new eremophilanes (dimeric lactones, lactams, carboxylic acid, methyl ester, tetranor- and dinor-ketones, furanoeremophilane, enoleremophilanolide, epoxyeremophilanolide, and hydroxy- or methoxyeremophilanolides) have been isolated from the methanol extract of fresh rhizomes of Farfugium japonicum (Compositae), and their structures have been determined on the basis of high-resolution 2D NMR and X-ray crystallographic analyses as well as by chemical transformations.