Synthesis of Azaisoflavones and Evaluation of Their Inhibitory Effects on IL-5

Sophoricoside analogs are natural isoflavonoids isolated from fruits of Sophora japonica L. and exhibited an inhibitory effect on IL -5. Many synthetic variations on isoflavonoids has been reported. but relatively few examples of quinolone analogs have been described. As part of our endeavor to develop novel and effective IL-5 inhibitor, we have synthesized azaisoflavones by cyclization of the key intermediate, 2'-aminochalocone obtained from substituted aniline. The synthesized azaisoflavones were evaluated for their inhibitory activtities on IL-5 comparing with natural Sophoricoside analogs. None of the azaisoflavones showed promixing inhibitory effects In the assay. Nevertheless. assay data Indicated that 5.7-phenolic hycroxy groups on the A-ring and alkyl subsitiuent on N1 seemed to play an importnt role in the IL-5 bioassay.