Hyperterpenoids A and B: Two pairs of unprecedented 6/6/4/6/6 polycyclic cyclobutane meroterpenoids with potent neuroprotective and anti-inflammatory activities from Hypericum beanii

Hyperterpenoid A (1) and B (2), two pairs of enantiomers, with an unprecedented 6/6/4/6/6 polycyclic skeleton, were isolated from Hypericum beanii. Their absolute configurations were elucidated by extensive NMR and single-crystal X-ray diffraction methods and the related plausible biogenetic pathways, significant neuroprotective activity and potential anti-inflammatory activity were also presented.