Abstract: To study the chemical constituents of ethyl acetate extract from Diaphragma juglandis Fructus for clarifying its pharmacological basis,the high-speed counter-current chromatography,reversed phase C₁₈ column chromatography and preparative high performance liquid chromatography were used for the separation and purification.Their chemical structures were identified by spectroscopic datas including electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR).Ten compounds were isolated and their chemical structures were identified as 2,3-dihydro-3-hydroxy-2-oxo-1H-indole-3-acetic acid (1),juglanin D (2),2-hydroxycinchoninic acid (3),C-veratroylglycol (4),quercetin 3-O-(6″-O-galloyl)-β-galactoside (5),quercetin 3-O-(6″-O-galloyl)-β-glucoside (6),hyperoside (7),isoquercitrin (8),isosclerone (9) and quercetin (10).Compound 3,7 and 8 are isolated from Diaphragma juglandis Fructus for the first time and compound 1,4 and 6 are found in this genus for the first time.The anti-inf1ammatory activity of isolated compounds was evaluated by the levels of NO in LPS-induced RAW264.7 tested by Griess reagent.And compound 10 showed strong anti-inf1ammatory activity.

Key words: Diaphragma juglandis Fructus, chemical constituents, identification, anti-inflammatory activity