Hymenosides A-F, Six New Hemiterpene Glucosides from the Japanese Fern Hymenophyllum barbatum.

Abstract
In the course of investigation of the bitter-tasting substances of the Japanese fern Hymenophyllum barbatum belonging to the family Hymenophyllaceae, six new hemiterpene glucosides called hymenosides A-F (1-6) have been isolated from the methanol extract, together with an acyclic bis-bibenzyl derivative, perrottetin H. This paper deals with the structure elucidation of the newly isolated glucosides.