Discovery and biological evaluation of dispirocyclic and polycyclic ent-clerodane dimers from Isodon scoparius as novel inhibitors of Toll-like receptor signaling

Three novel ent-clerodane dimers (1–3) were discovered. 2 and 3 exhibited remarkable immunosuppressive activity on the activation of purified B cells and significantly abrogated the downstream pathway of TLR7 signaling.