Six New Constituents from the Fruit of Hypericum patulum and Their Anti-Inflammatory Activity

Abstract

Four new xanthone glucosides, 3-hydroxy-2-methoxyxanthone-4-O-β-D-glucopyranoside (1), 4,8-dihydroxy-2-methoxyxanthone-3-O-β-D-glucopyranoside (2), 2-methoxyxanthone-5-O-β-D-glucopyranoside (3), 4-hydroxy-2-methoxyxanthone-3-O-β-D-glucopyranoside (4), a new phenolic acid, 4,4'-dihydroxy-3,3'-imino-di-benzoic acid monomethyl ester (5), and a new isoquinoline, methyl 6-hydroxy-1-oxo-1,2,3,4-tetrahydroisoquinoline-4-carboxylate (6) were isolated from the fruit of Hypericum patulum. The structural elucidation of the isolated compounds was primarily based on HR-ESI-MS, UV, IR, 1D and 2D NMR. All compounds were evaluated for their inhibitory effect against LPS-induced NO production in RAW 264.7 cells. Compound 2, 3 exhibited moderate inhibitory activity against NO production.

Keywords: Hypericum patulum; RAW 264.7; anti-inflammatory activity; isoquinoline; phenolic acid; xanthone.