LAUSR

Abstract Phytochemical investigation of the bark of Juglans mandshurica led to the isolation of two new coumarins, juglansoside A–B (1–2), along with five known compounds (3–7). The structures of new compounds were elucidated by comprehensive spectroscopic analyses. All compounds were evaluated for their cytotoxicity in vitro using two human hepatocellular carcinoma cell lines (Hep3B and HepG2). Among them, compounds 1 and 2 displayed moderate cytotoxicity against HepG2 cells with IC50 values of 61.07 μM and 64.46 μM, respectively. Compounds 4 and 5 were moderately active, with IC50 values of 55.40 μM and 66.97 μM against Hep3B cells, respectively. Moreover, Annexin V-FITC/PI staining assay was used to investigate whether the cytotoxic activities of 1–2 and 4–5 were due to cell apoptosis. The results indicated that 1–2 markedly induced apoptosis in HepG2 cells, and 4–5 effectively caused apoptosis in Hep3B cells.