Stability of quercetin in DMEM and cell culture with A549 cells

Abstract Quercetin is evidently unstable in Dulbecco's modified Eagle's medium (DMEM) at 37°C. However, the underlying mechanism of this instability is not clear yet. The stability and new degradation products of quercetin in DMEM at 37°C were investigated via in UPLC‐MS‐MS analysis. With increasing incubation time, quercetin formed various degradation products derived from its dimer and there were numerous isomers formed during this process. Ascorbic acid significantly improved the stability of quercetin by protecting quercetin from auto‐oxidation in this medium. Ascorbic acid also remarkably enhanced the stability of quercetin in DMEM in the presence of A549 cells and obviously increased the antiproliferative effect of quercetin toward A549 cells.