Spiropatuols A-H: Polycyclic Polyprenylated Acylphloroglucinols from Hypericum patulum with Activity against Concanavalin A-Induced Autoimmune Hepatitis.

Eight new spiropolycyclic polyprenylated acylphloroglucinols, named spiropatuols A-H (1-8), were isolated from the traditional Chinese medicinal herb Hypericum patulum. The structures of compounds 1-8 were characterized using spectroscopic analysis, calculations of nuclear magnetic resonance chemical shifts with DP4+ probability analysis, and electronic circular dichroism calculations. Compounds 2-4 exhibited immunosuppressive activities in an in vitro model of concanavalin A (Con A)-induced murine splenocyte proliferation, with half-maximal inhibitory concentrations of 50, 70, and 200 nM, respectively. Furthermore, in a Con A-challenged autoimmune hepatitis mouse model, compound 2 inhibited Con A-induced activation of mice splenic lymphocytes and alleviated Con A-induced acute liver injury. These results indicate that the metabolites isolated in this study can inform the design of novel immunosuppressors for treating autoimmune hepatitis.