Isolation and Characterization of Flavonolignan from Cucumis bisexualis and Their Hepatoprotective Activities

Cucumis bisexualis is a delicious fruit with diverse constituents and multiple bioactivities. A novel flavonolignan, named 2-(3′-methoxyphenyl)-(4′→1′′)-O-β-D-glucopyranosyl-7′′′-(4′′′-methoxyphenyl)-pyrano-chromene-4,9′′′-dione (1), and five known flavonolignan derivatives (2–6) were isolated from C. bisexualis for the first time. These compounds (1–6) were identified by their spectral data and reported references. The hepatoprotective activities of compounds (1–6) on HepG2 cells were evaluated with quercetin as positive control. As a result, compounds 1, 3, 4 were found to exhibit moderate hepatoprotective activity.