Abstract: Eleven compounds were isolated from Pericarpium Juglantis, and their structures were identified as 2-hydroxy-1,4-naphthoquinone (1), 5-hydroxy-1,4-naphthoquinone (2), 2,5-dihydroxy-1,4-naphthoquinone (3), 2,5-dihydroxy-1,4-naphthoquinone (4), 2,5-dihydroxy-1,4-naphthoquinone (5), 5-methoxy-1,4-naphthoquinone (6), 5,7-dihydroxychromone (7), isovanillic acid (8), gallic acid (9), β-sitosterol (10), and β-daucosterol (11) by means of their physic-chemical properties and spectroscopic ways. In the cytotoxic assay, 3 and 4 exhibited significant inhibitory effects against HepG2 cancer cell lines with IC₅₀ value of 5.0±0.6 mol/L and 7.0±0.5 mol/L, respectively. And 2 and 5 showed significant inhibitory effects against HL-60 cancer cell lines with IC₅₀ value of 9.3±1.2 mol/L and 2.3±0.2 mol/L, respectively.

Key words: Juglans mandshurica, chemical constituents, structural identification, cytotoxic activity