The structures of four diarylheptanoid glycosides from the female flowers of Alnus serrulatoides

Abstract

Four diarylheptanoid monoglycosides (2a), (2b), (3), and (4), in addition to the hydroxy ketone (1), were isolated from the female flowers of Alnus serrulatoides. On the basis of the physicochemical and the X-ray crystallographic analyses, these were characterized as (5S)-1,7-bis(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one (1), (5S)-1-(4-hydroxyphenyl)-7-(3,4-dihydroxyphenyl)-5-(β-D-xylo-pyranosyloxy)heptan-3-one (2a), (5S)-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-5-(β-D-xylo-pyranosyloxy)heptan-3-one (2b), (5S)-1,7-bis(3,4-dihydroxyphenyl)-5-(β-D-xylopyranosyloxy)-heptan-3-one (3), and (5S)-1,7-bis(3,4-dihydroxyphenyl)-5-(β-D-glucopyranosyloxy)heptan-3-one (4), respectively. Of these compounds, the glycosides (2a), (2b), and (4) are new.