Structurally diverse coumarin-homoisoflavonoid derivatives with hepatoprotective activities from the fruits of Cucumis bisexualis

Cucumis bisexualis is a favorite wild fruit with high nutritional and medicinal values because of its bioactive constituents. Four previously undescribed coumarin-homoisoflavonoid derivatives (1–4), together with seven known coumarin and homoisoflavonoid derivatives (5–11) were isolated from the fruits of C. bisexualis for the first time. All the compounds were elucidated by their extensive and comprehensive spectroscopic data and references. Compounds (1−11) were evaluated for their hepatoprotective activities in HepG2 cells by the acetaminophen (APAP)-induced damage model at 10.0 μM with bicyclol as the positive control. Among them, compounds 1, 3, 5, and 6 showed moderately hepatoprotective activities to improve the HepG2 cell survival rates from 51.68 ± 2.49% (APAP, 10 mM) to 71.55 ± 4.08%, 65.95 ± 4.39%, 60.77 ± 3.44%, 62.94 ± 2.30%, respectively.