Synthesis, biological evaluation of chrysin derivatives as potential immunosuppressive agents

A series of novel chrysin derivatives was firstly synthesized and evaluated on their immunosuppressive activity in the search for potential immunosuppressive agents. Among them, compounds 5c displayed the most potent immunosuppressive inhibitory activity with IC(50) of 0.78 μM, which was comparable to that of cyclosporin A (IC(50) = 0.06 μM). The preliminary mechanism of compound 5c inhibition effects was also detected by flow cytometry (FCM), and the compound exerted immunosuppressive activity via inducing the apoptosis of activated lymph node cells in a dose dependent manner. Furthermore, the estimated LD(50) (in mg/kg) in vivo of compound 5c is 738.2, which indicated that compound 5c was low toxic.