Kaneyuki T, Noda Y, Traber M G, Mori A, Packer L
Faculty of Health and Welfare Science, Department of Nutritional Science, Okayama Prefectural University, Soja, Japan.
Biochem Mol Biol Int. 1999 Jun;47(6):979-89. doi: 10.1080/15216549900202103.
Radical scavenging by reconstituted lyophilized powders of water extracts from 16 common vegetables was measured using electron spin resonance (ESR) with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), hydroxyl radicals, (.OH) or superoxide anion radicals (O2.-), as DMPO-OH or DMPO-OOH spin adducts. On a dry weight basis, eggplant, and red, yellow and green bell pepper extracts showed potent superoxide anion radical scavenging activities (SOD-like activities). Ascorbate oxidase- or heat-treatments, decreased SOD-like activities in bell pepper extracts suggesting that ascorbate accounts for much of their free radical scavenging activity. Eggplant epidermis extract exhibited the most potent hydroxyl radical scavenging and SOD-like activities. Eggplant SOD-like activity did not decrease after ascorbate oxidase treatment, but decreased following ultrafiltration demonstrating that SOD-like activity is partially due to high molecular weight substances. Nasunin, an anthocyanin in eggplant epidermis, showed markedly potent superoxide anion radical scavenging activity, while it inhibited hydroxyl radical generation probably by chelating ferrous ion.
采用电子自旋共振（ESR），以5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）作为自旋捕获剂，检测16种常见蔬菜水提取物冻干粉末对羟基自由基（·OH）或超氧阴离子自由基（O₂⁻·）的清除能力，分别生成DMPO-OH或DMPO-OOH自旋加合物。以干重计，茄子以及红、黄、绿甜椒提取物表现出较强的超氧阴离子自由基清除活性（类超氧化物歧化酶活性）。抗坏血酸氧化酶处理或热处理后，甜椒提取物中的类超氧化物歧化酶活性降低，这表明抗坏血酸是其自由基清除活性的主要成分。茄子表皮提取物表现出最强的羟基自由基清除活性和类超氧化物歧化酶活性。茄子的类超氧化物歧化酶活性在抗坏血酸氧化酶处理后未降低，但超滤后降低，这表明类超氧化物歧化酶活性部分归因于高分子量物质。茄子表皮中的花青素纳斯菌素表现出显著的超氧阴离子自由基清除活性，同时它可能通过螯合亚铁离子来抑制羟基自由基的产生。
