半胱氨酸类生物分子是生物体中一类关键的抗氧化剂，在维护生命健康和延缓衰老过程中发挥着不可替代的作用。研究结果表明在生理环境下该类抗氧化剂氧化过程可能经历多种可逆或者不可逆氧化反应途径（即二硫键、S-N键等氧化还原反应过程和R-SO3H等不可逆反应过程）。本项目以这类抗氧化剂在机体内的几种典型的氧化还原反应为原型，拟采用电喷雾流动管离子氧化反应源方法、气相慢电子速度成像技术和高精度理论计算方法，确认简单分子的关键反应中间体和产物结构信息及其相对稳定性，并研究在气-液界面条件下改变pH值等条件对其反应过程的影响，深入理解抗氧化剂对生命健康调控的微观反应机制。探索复杂的抗氧化剂(如谷胱甘肽)的氧化过程以及反应过程中存在的中间体等，为揭示S-S、S-N键的形成和R-SO3H的氧化还原循环过程提供重要的参考价值，并探索可能存在的新的氧化还原途径，为生命健康监测和疾病防治提供新的线索和方案。

As a key antioxidant in vivo, cysteine and its derivatives play a vital role in the maintenance of health and anti-aging. The results suggest that the cysteine-containing antioxidants are possibly oxidized via several reversible or irreversible reaction pathways under oxidative conditions in cell physiological environment (reversible reaction: disulfide bond and S-N bond species et al.; irreversible reaction: R-SO3H species). In the present proposal, as the prototype of redox reaction of the cysteine-containing antioxidants in vivo, the research focuses on the identification of the key reaction intermediates and products in the gas phase via electronspray ionization flow tube oxidation reaction source, slow electron velocity map imaging and high accuracy theoretical calculation methods. The results will shed light on the deeply understanding of the microscopic oxidation mechanism of the antioxidants to the regulation in health. To explore the oxidation mechanism of the complex antioxidants (such as glutathione), the research is performed to reveal the formation of disulfide bond, S-N bond and R-SO3H species. The possible new reaction pathways revealed in the research will provide new clues and proposals for the health monitoring and disease controlling.