Chalcone skeleton promotes transcription of gp91‐phox gene but inhibits expression of gp91‐phox protein, and hydroxyl groups in hydroxychalcones participate in the stable expression of gp91‐phox protein

The effects of chalcone and butein on the induction of the superoxide anion (O2‐)‐generating system were studied in U937 cells by all‐trans retinoic acid (RA). The chalcone skeleton, a common structural motif in them, significantly enhanced the transcription of gp91‐phox in an epigenetic manner. In contrast, chalcone and butein showed opposite effects on the induction of the O2‐‐generating activity by RA and the expression of gp91‐phox protein. Chalcone inhibited, whereas butein promoted, the induction of O2‐‐generating activity by RA and the expression of gp91‐phox protein. These data raise the possibility that modification of the chalcone skeleton could produce more effective differentiation‐promoting agents.