STYRYLPYRONE GLUCOSIDES FROM EQUISETUM

Two styrylpyrone glucosides, 3'-deoxyequisetumpyrone roxy-E-styryl)-2- pyron-3-O-beta-D-glucopyranoside) and hoxy-E-styryl)-2-pyron-3-O-beta- D-glucopyranoside) have been isolated from the rhizomes of Equisetum a rvense. The structures of the new derivatives were elucidated spectros copically. These compounds are accumulated as the main phenolics in rh izomes and gametophytes of all Equisetum species. In these organs, the y represent a sink for compounds derived from hydroxycinnamoyl CoA est ers and malonyl units, whereas sporophytic shoots contain no styrylpyr ones but a considerable variety of flavonoid glycosides.