Cytotoxic phenylpropanoid glycosides from Fagopyrum tataricum (L.) Gaertn.

Fagopyrum tataricum (L.) Gaertn (tartary buckwheat) is an ancient dicotyledonous crop belonging to Polygonaceae family. Besides its benefits for human consumption, tartary buckwheat is also an important folk medicine in China for its antioxidant, antitumour, hypotensive, hypoglycaemic and hypolipidaemic activities. Phytochemical investigation of the ethyl acetate fraction of tartary buckwheat roots led to the isolation of seven new phenylpropanoid glycosides, tatarisides A-G (1-7), together with a known phenylpropanoid glycoside, diboside A (8). Their structures were elucidated by means of spectroscopic methods. All compounds (1-8) were evaluated for their cytotoxic activity against four human cancer cell lines (A-549, HCT116, ZR-75-30 and HL-60). Tatariside C (3) was the most active compound with IC50 values of 6.44-7.49μg/ml against the four tested cell lines.