Rearranged Homoadamantane-Type Polycyclic Polyprenylated Acylphloroglucinols from Hypericum pseudohenryi

Hypseudohenones A–C (1–3), the first rearranged homoadamantane-type polycyclic polyprenylated acylphloroglucinols, were isolated from Hypericum pseudohenryi. Their structures with an unprecedented tricyclo[4.3.1.13,8]undecane-2,4,10-trione core were determined by spectroscopic analysis, quantum-chemical calculations, and X-ray crystallography. A method for determining the relative configuration at C-3 was established by the peak shape of H-28 or J-value of H-3/H-28. Moreover, 2–3exhibited significant AChE inhibitory activity, and the interactions of 2–3with AChE were evaluated by molecular docking.