Hypseudohenrin H, a highly-cyclized polycyclic polyprenylated acylphloroglucinol derivative from Hypericum pseudohenryi

Hypseodohenrin H (1), a cyclization product of nor-BPAPs with a 6/5/5 tricyclic ring system was characterized, along with it ring opening product, 1,7-seco-norhypseodohenrin (2). Their structures were elucidated by NMR, MS, and XRD analysis. Different from other cyclization product of nor-BPAPs that underwent a free radical process, the transformation from 1 to 2 was an ionic process. The bioactivity screening results showed that compounds 1 and 2 exhibited potent hepatoprotective activity with EC50 value of 5.99 μM and 3.65 μM, respectively.