Hyperacmosin N, new acylphloroglucinol derivative with complicated caged core from Hypericum acmosepalum

Abstract Three new polycyclic polyprenylated acylphloroglucinol derivatives, hyperacmosins N–P (1–3), were isolated from the air-dried aerial parts of Hypericum asmosepalum. Especially, compound 1 possessed a rare hexacyclic core, which was formed via oxidation and radical cyclization. Their structures were established by NMR, HRMS (ESI), and experimental electronic circular dichroism (ECD) spectra. The plausible biogenetic pathways of 1-3 were proposed, which gave an insight for future biomimetic synthesis of the novel compounds.