Seven filicinic acid–based
meroterpenoids (1–7), possessing
6/6/11, 6/6/7/5, or 6/6/10 ring
systems, were isolated from Hypericum japonicum.
All of them have novel skeletons with the incorporation of sesquiterpenoid
moieties to an acylated filicinic acid. Compounds 2a and 4 exhibited significant efficacy on anti-Epstein–Barr
virus, with EC50 values of 0.57 and 0.49 μM, respectively.
Furthermore, compounds 2a and 4 were well
accommodated to the binding pocket of 2GV9 predicted by the molecular
docking.