Unusual terpenylated acylphloroglucinols from Dryopteris wallichiana

► An extract of the rhizomes and roots of the fern Dryopteris wallichiana was examined. ► Four terpenylated phloroglucinols and four known compounds were obtained. ► The absolute configuration of wallichins A-D was established by ECD calculations. ► All evaluated compounds showed moderate nematocidal activity. ► Some qualitative structure-activity relationships could be derived.