State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
J Agric Food Chem. 2010 Jan 13;58(1):587-93. doi: 10.1021/jf9028656.
Alcalase-treated zein hydrolysate (ZH) was separated by gel filtration, ultrafiltration, and reversed-phase HPLC, and the scavenging activities for 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+), 1,1-diphenyl-2-picrylhydrazyl (DPPH*), and superoxide anion (O2*-) radicals of different peptide fractions were measured to establish the antioxidant efficacy. Results showed that the ability to stabilize water-soluble free radicals (ABTS*+) by ZH components was insensitive to the peptide size, whereas that against ethanol-soluble free radicals (DPPH*) and O2*- was molecular weight dependent. Antioxidative peptides of <1 kDa were further separated by HPLC into 30 components, of which those with great hydrophobicity exhibited strong DPPH* and O2*- scavenging ability and those with intermediate hydrophobicity displayed the maximum ABTS*+ scavenging activity. Two dominant components (fractions 8 and 17) were further purified and identified by LC-PDA-ESI-MS to be Tyr-Ala and Leu-Met-Cys-His, respectively. The results demonstrated that the free radical scavenging activity of ZH depended on the radical species and was strongly related to the molecular weight and hydrophobicity of the constituting peptides.
经 Alcalase 处理的玉米醇溶蛋白水解物 (ZH) 通过凝胶过滤、超滤和反相 HPLC 进行分离，测量不同肽段对 2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）（ABTS*+）、1,1-二苯基-2-苦基肼（DPPH*）和超氧阴离子（O2*-）自由基的清除活性，以确定其抗氧化功效。结果表明，ZH 成分稳定水溶性自由基（ABTS*+）的能力对肽的大小不敏感，而对乙醇溶性自由基（DPPH*）和 O2*-的清除能力则与分子量有关。<1 kDa 的抗氧化肽进一步通过 HPLC 分离成 30 个组分，其中疏水性强的组分具有较强的 DPPH和 O2-清除能力，而疏水性中等的组分则具有最大的 ABTS*+清除活性。两种主要成分（第 8 部分和第 17 部分）通过 LC-PDA-ESI-MS 进一步纯化和鉴定，分别为 Tyr-Ala 和 Leu-Met-Cys-His。结果表明，ZH 的自由基清除活性取决于自由基种类，与构成肽的分子量和疏水性密切相关。
