Discovery of bioactive polycyclic polyprenylated acylphloroglucinols with adamantine/homoadamantane skeletons from Hypericum wilsonii.

In this work, nine previous undescribed polycyclic polyprenylated acylphloroglucinols with adamantine/homoadamantane skeletons, cumilcinols A-I (1-9), along with six known analogues, were isolated and identified from the stems, leaves and flowers of Hypericum wilsonii. Their structures were determined by HRESIMS, NMR spectroscopic analysis, single-crystal X-ray crystallography as well as electronic circular dichroism calculations and comparisons. Compound 2 formed a unique furan ring bearing a rare acetal functionality. In bioassays, hyperacmosin G (13) could significantly inhibit the production of NO in LPS-stimulated RAW264.7 cell (IC = 4.350 ± 1.146 μM), and increased expression of related transcription factors at the gene level, inhibit the nuclear translocation of NF-κBp65, and reduce the protein expression of COX-2. Additionally, compound 5 showed significant inhibitory activity on Con A-induced T-lymphocyte proliferation (IC = 4.803 ± 3.149 μM), and treatment of 5 could reduce the increased ratio of CD4 and CD8 subpopulations induced by Con A in vitro. Those results indicated 13 possesses potential anti-inflammatory activity, and 5 exhibits a certain degree of immunosuppressive activity.