Bioassay-guided isolation of an abetiane-type diterpenoid from Prunella vulgaris That protects against concanavalin A-induced autoimmune hepatitis. - GreenMedInfo Summary

is a widely used edible Chinese medicinal plant. In the present study, two new abietane-type diterpenoids, abietoquinones A () and B (), were isolated from this plant by an immunosuppressive bioassay-guided isolation procedure. Their structures were elucidated unambiguously by NMR spectroscopic analysis, single-crystal X-ray crystallography, and electronic circular dichroism calculations. Compoundsandbear a cyclohex-2-ene-1,4-dione moiety, which is uncommon among abietane diterpenes. Also, abietoquinone A () suppressed murine splenocyte proliferation and decreased the production of proinflammatory cytokines induced by concanavalin A (Con A) in vitro. In Con A-challenged mice, preinjection withsignificantly ameliorated liver injury. Additionally, abietoquinone A () exhibited inhibitory activities against the proliferation of murine splenocytes and human T cells induced by anti-CD3/anti-CD28 monoclonal antibodies (mAbs).