Hypersine H, One Undescribed Xanthone From the Hypericum elodeoides Choisy With Anti-Neuroinflammation Activity.

One undescribed xanthone, hypersine H (1), together with three known analogs, 3,7-dihydroxy-1-methoxyxanthone (2), 1,7-dihydroxy-5,6-dimethoxyxanthone (3), and 1,5-dihydroxy-6,7-dimethoxyxanthone (4), were isolated from the whole plant of Hypericum elodeoides Choisy. Their structures, including absolute configurations, were unambiguously elucidated by HR-ESI-MS, extensive NMR spectroscopy, and quantum chemical calculation of electronic circular dichroism (ECD) method. Moreover, the anti-neuroinflammation activities of isolated compounds were evaluated. As a result, Compounds 1-2 decreased the production of nitric oxide (NO) in LPS-stimulated mouse BV2 microglia. Further mechanism study indicated that 1 and 2 exerted anti-neuroinflammation effects by suppressing the expression of pro-inflammatory enzymes, including inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. Above all, compounds 1-2 showed promise as useful therapeutic agents in the treatment of neurodegenerative diseases caused by neuroinflammation.