Study on flavonoids from green walnut husks of Juglans mandshurica / 中草药

ABSTRACT

Objective: To study the chemical constituents from the green walnut husks of Juglans mandshurica. Methods: The chemical constituents from the green walnut husks of J. mandshurica were isolated and purified by repeated silica gel, Sephadex LH-20 column chromatography and ODS column chromatography, and their structures were identified by NMR spectral analysis. Results: A total of 14 compounds were isolated from the green walnut husks of J. mandshurica, and identified as apigenin (1), tricin (2), eupatilin (3), 3,7,8,3’-tetrahydroxy-4’-methoxyflavone (4), 3,5-dihydroxy-7-methoxy-3’,4-methylenedioxyflavone (5), taxifolin (6), quercetin-3-O-(6″-galloyl)-β-D-galactopyranoside (7), quercetin-3-O-(4″-O-acetyl)-α-L-rhamnopyranoside (8), engeletin (9), isoengeletin (10), kaempferol-3-O-β-D-glucopyranoside (11), quercetin-3-O-β-D-glucuronide (12), quercetin-3-O-β-D- glucopyranoside (13), and myricetin-3-O-β-D-glucuronide (14). Conclusion: Compounds 1-10, 12, and 14 are isolated from the green walnut husks of J. mandshurica for the first time.