College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China.
J Agric Food Chem. 2012 May 30;60(21):5431-7. doi: 10.1021/jf3017173. Epub 2012 May 17.
Defatted peanut meal hydrolysate (DPMH) was purified using ultrafiltration, gel filtration chromatography, and high-performance liquid chromatography. A tripeptide with strong oxygen radical absorbance capacity (ORAC) was isolated and identified as Tyr-Gly-Ser by ESI-MS/MS. It was then synthesized to measure its antioxidant properties in different systems. The ORAC value of Tyr-Gly-Ser was 3-fold higher than that of glutathione (GSH), and it displayed a stronger protective effect on linoleic acid peroxidation and H(2)O(2)-induced oxidative injury in rat pheochromocytoma line PC12 cells than GSH (p < 0.05). However, Tyr-Gly-Ser showed negligible DPPH radical scavenging activity, reducing power, and no metal chelating ability. The results suggested that Tyr-Gly-Ser displayed antioxidant activity via the hydrogen atom transfer mechanism, and the Tyr at the N-terminal was the hydrogen donor. The ORAC assay was recommended as a reliable and effective method to measure the antioxidant activity in the course of antioxidant peptide isolation.
脱脂花生粉水解产物（DPMH）通过超滤、凝胶过滤色谱和高效液相色谱进行了纯化。分离出一种具有强氧自由基吸收能力（ORAC）的三肽，并通过 ESI-MS/MS 鉴定为 Tyr-Gly-Ser。然后合成了该三肽以在不同体系中测量其抗氧化性质。Tyr-Gly-Ser 的 ORAC 值比谷胱甘肽（GSH）高 3 倍，并且它对大鼠嗜铬细胞瘤 PC12 细胞中亚油酸过氧化和 H（2）O（2）诱导的氧化损伤的保护作用强于 GSH（p < 0.05）。然而，Tyr-Gly-Ser 对 DPPH 自由基几乎没有清除活性、还原能力，也没有金属螯合能力。结果表明，Tyr-Gly-Ser 通过氢原子转移机制发挥抗氧化活性，并且 N 末端的 Tyr 是氢供体。建议使用 ORAC 测定法作为在抗氧化肽分离过程中测量抗氧化活性的可靠和有效的方法。
