New Flavonoid Glycosides from Elsholtzia rugulosa Hemsl.

Elsholtzia rugulosa Hemsl. is known in China as a local herbal tea, medicinal herb and honey plant. Chemical examination of E. rugulosa led to the isolation of two new flavonoid glycosides, apigenin 4 '-O-alpha-D-glucopyranoside (1) and 5,7,3 ',4 '-tetrahydroxy-5 '-C-prenylflavone-7-O-beta-D-glucopyranoside (2), together with nine known flavonoids. Their structures were elucidated on the basis of spectroscopic evidence.