Discovery and synthesis of novel glyrrhizin-analogs containing furanoylpiperazine and the activity against myocardial injury in sepsis

The signaling pathway mediated by high mobility group protein B1 (HMGB1) plays a key role in myocardial injury during sepsis. Glyrrhizin (GL) is a natural product that inhibits HMGB1 biological activities through forming GL-HMGB1 complex; the research shows its aglycone (GA) is the main pharmacophore binding to HMGB1, while the glycosyl mainly altering its pharmacokinetic properties and enhances the stability of the complex. GL is often metabolized to GA in the gastrointestinal tract, which has a lower efficacy in the treatment of HMGB1-mediated diseases. To obtain the GL analogs with higher activity and better pharmacokinetic properties, 24 GL analogs were synthesized by simplification the glycosyl of GL. Among all the compounds, compound 11 with furanoylpiperazine was screened. The pharmacokinetics experiments showed that compound 11 is converted to 11a in vivo, and 11 serves as its prodrug. Compound 11a displayed a lower cytotoxicity to RAW264.7 cells and three types of cardiomyocyte lines, with IC