Carbonate radicals play a crucial role in the mechanism of resveratrol degradation in bicarbonate solution

) is a key factor promoting the resveratrol (Res) degradation in culture media, yet the underlying mechanism remains unclear. This study investigated the role of carbonate radicals in the bicarbonate-promoted Res degradation in aqueous systems. The Res degradation and hypotaurine-taurine conversion, an indicator of carbonate radical formation, were analyzed by the high-performance liquid chromatography, while radical generation was monitored by the electron paramagnetic resonance (EPR) spectroscopy. Significant Res degradation occurred in the bicarbonate solutions even under the mildly acidic conditions, whereas the degradation in the NaOH was observed only at pH 8.7. The EPR analysis revealed the reactive radical formation, and the taurine production confirmed the presence of carbonate radicals. The addition of hypotaurine, superoxide dismutase, or dimethyl sulfoxide markedly suppressed the Res degradation, taurine formation, and the EPR signals. These results demonstrate that the carbonate radicals play a critical role in the Res oxidative degradation in the bicarbonate systems, and a mechanistic pathway is therefore proposed.