Focusing on 2, 2′-pyridoin (1, 1, 2-di (2-pyridyl)-1, 2-ethenediol) and its synthetic derivatives as the lead compound of the potent antioxidative enediol, their protective effect against oxidative stress was evaluated on the HL-60 cell system. 2, 2′-Pyridoins showed no remarkable cytotoxic effect on HL-60 cells. The derivatives 1, 2, 3, 5, and 6 inhibited H2O2-induced cell death and intracellular oxidative stress more significantly than ascorbic ...