New arbutin derivatives from the leaves of Heliciopsis lobata with cytotoxicity.

Heliciopsis lobata is a medicinal plant, which is exclusively used to treat tumor in Li folk region. Two new arbutin derivatives, 6'-((E)2-methoxy-5-hydroxycinnamoyl) arbutin (1) and 2'-((E)2, 5-dihydroxycinnamoyl) arbutin (2) along with five known compounds (3-7), were isolated from the leaves of Heliciopsis lobata. Their structures were elucidated on the basis of extensive spectroscopic interpretations. They were evaluated for their potential anticancer activity. Compounds 6 and 7 exhibited cytotoxicity against MGC-803 cells with IC50 values being 44.1 and 11.3 μg·mL(-1), respectively. Additionally, compounds 1, 2 and 5-7 exhibited a moderate inhibition of MGC-803 cells invasion; compound 2 at 20 μg·mL(-1) inhibited the invasion of MGC-803 cells by 43.0%, compared with the controls.