Hybeanones A and B, Two Highly Modified Polycyclic Polyprenylated Acylphloroglucinols from Hypericum beanii

Comprehensive Summary Hybeanones A and B ( 1 and 2 ), two highly oxygenated and rearranged polycyclic polyprenylated acylphloroglucinols (PPAPs), were isolated from the aerial parts of Hypericum beanii . Their structures comprising absolute configurations were elucidated by spectroscopic analysis, single‐crystal X‐ray diffraction, and quantum chemical calculations. Compounds 1 and 2 are defined by a newly assembled cyclopentanone unit fused to a tricyclic γ ‐lactone unit via a ketone carbonyl. The breakage of C‐1/C‐2 linkage via retro‐Claisen reaction, attack from C‐1 to C‐19, and Baeyer‐Villiger oxidation at C‐1/C‐23 bond were presumed to be the key steps in the assembly of 1 and 2 . The isolates 1 and 2 showed potential acetylcholinesterase (AchE) inhibitory activities, with IC 50 values of 21.34 ± 1.48 and 18.79 ± 2.36 μmol/L, respectively.