Abstract:
Eight compounds were isolated and purified from the ethyl acetate part of 70% acetone extract of
Rehmannia glutinosa by various chromatographic techniques such as silica gel, MCI gel CHP-20, ODS, Toyopearl HW-40C, combined with TLC and semi-preparative HPLC. Their structures were elucidated by modern spectroscopy techniques (NMR, MS, UV, IR), and identified as neomartynoside A (
1), osmanthuside B
6 (
2), martynoside (
3), isomartynoside (
4), (
E)-
p-hydroxycinnamic acid (
5), caffeic acid (
6), ferulic acid (
7), and methyl caffeate (
8). Compound
1 is a new phenylethanol glycoside, which was identified as neomartynoside A. Compound
2 was isolated from
Rehmannia glutinosa for the first time. In addition, compounds
2,
6 and
7 significantly increased relative glucose consumption, showing potential hypoglycemic activity.