Abstract A series of 3-nitrochromenes were designed and synthesized. These compounds showed good inhibitory activity against thioredoxin reductase (TrxR) and the proliferation of A549 cancer cells. The structure–activity relationship analysis indicates that the 3- nitrochromene scaffold is the crucial pharmacophore for achieving good inhibitory activity. The bromo-substitutions at the 6-and 8-position of 3-nitrochromene significantly increase ...