Antioxidant and Cytoprotective Effects of New Diarylheptanoids from .

(Zingiberaceae) has been an important food spice and vegetable in southern China. Fifteen phenolic compounds (-) including three new diarylheptanoids, rhynchanines A-C (-) and one new phenylpropanoid, 4--methylstroside B (), were isolated from rhizomes. The structures of new compounds were elucidated by comprehensive analyses through NMR, HRMS technique, acid hydrolysis, and Mosher's reaction. Among them, compound is the first isolated natural product and its NMR data are reported. Most of the isolated compounds, especially - and , showed significant antioxidant activities on DPPH, ABTS radical scavenging, and FRAP assays. Furthermore, the antioxidant phenolic compounds were evaluated for their cytoprotective capacity against HO-induced oxidative stress in HepG-2 cells. Compounds and could significantly inhibit reactive oxygen species production, and compounds , , and could remarkably prevent the cell apoptosis. Then, the rhizome, which contained phenolic compounds, might serve as a functional food for potential application on preventing oxidative stress-connected diseases.