Absolute stereostructures of 3S-phyllodulcin, 3R- and 3S-phyllodulcin glycosides, and 3R- and 3S-thunberginol H glycosides from the leaves of Hydrangea macrophylla seringe var. Thunbergii makino

A new dihydroisocoumarin, 3S-phyllodulcin, and nine new dihydroisocoumarin glycosides, 3R- and 3S-phyllodulcin 3'-O-glucosides, 3R- and 3S-thunbergino l K 8-O-glucosides, 3R- and 3S-thunberginol I 4'-O-glucosides, 3R- and 3S-h ydrangenol 4'-O-apiosylglucosides, and thunberginol I 8-O-gIucoside, were i solated from the leaves of Hydrangea macrophylla SERINGE var, thunbergii MA KINO. The absolute stereostructures of 3S-phyllodulcin, 3R- and 3S-phyllodu lcin 3'-O-glucosides, and 3R- and 3S-thunberginol H 8-O-glucosides were elu cidated on the chemical and physicochemical evidence. Phyllodulcin from the unprocessed leaves was found to be ca. a 5 : 1 enantiomer mixture at the 3 -position.