A new phenyl glycoside from the aerial parts of Equisetum hyemale.

A new phenyl glycoside, 2-(sophorosyl)-1-(4-hydroxyphenyl) ethanone (9), was isolated from the ethanolic extract of the aerial parts of Equisetum hyemale L., together with eight known compounds (1-8). The structures of these compounds were elucidated using a combination of spectroscopic analyses and chemical method. Of these nine compounds, 4 and 7 showed hepatoprotective effects towards tacrine-induced cytotoxicity in Hep 3B cells with EC50 values of 42.7 +/- 1.5 and 132.6 +/- 2.8 mu M, respectively.