摘要
应用化学发光方法研究了4种儿茶素及其组合物对超氧阴离子自由基(O·2-)和羟自由基(OH·)的清除能力,并对其之间的清除能力进行了比较。结果表明:EGCG、ECG、EGC和EC的O·2-清除率为50%时的浓度SC50分别为4.2、4.9、5.2和6.2μmol/L,而OH·清除率为50%时的浓度SC50则分别为0.22、0.25、0.26和0.30μmol/L。4种儿茶素的浓度相同时,其O·2-和OH·清除率的大小顺序为:EGCG>ECG>EGC>EC。并应用正交试验设计方法来优化4种儿茶素的组合,结果表明:清除O·2-和OH·的最佳组合是EGCG∶ECG∶EGC∶EC为3∶3∶1∶1。EGCG对自由基清除率影响是最大和最显著的。在4种儿茶素的组合中,当EGCG所占的比例较大时,其组合物的自由基清除率比单体的自由基清除率要大。文中最后还模拟了不同茶叶中4种儿茶素所占的比例不同时,其清除自由基的能力的大小。本研究为利用儿茶素的不同配伍寻找一种更能发挥其药用功效的复合物提供了一条新的途经。
The objectives of this paper were to study the free-radical scavenging abilities of four catechins and their blended composite toward superoxide radical anion （O^＊2^-） and hydroxyl radical （OH^＊）, and to make a comparison with each other using a chemiluminescence technique. The results showed that EGCG, ECG, EGC and EC could scavenge O^＊2^- at SC50 values of 4.2, 4.9, 5.2 and 6.2 μmol/L respectively, and scavenge OH＇ at SC50 values of 0. 22, 0. 25, 0. 26 and 0. 30μmol/L respectively. The scavenging rates at the same total concentration of four catechins were as follows： EGCG 〉 ECG 〉 EGC 〉 EC. In addition, orthogonal experimental was used to obtain the optimal ratio of four catechins. The optimal blended composite of scavenging rate toward O^＊2^- and OH^＊ were found to be EGCG ： ECG ： EGC ： EC 3 ： 3 ： 1 ： 1. EGCG was the most important factor and was of the most significance. The scavenging rate of four-catechin composite was higher than those of corresponding individual catechins while EGCG in the composite was high in proportion.
出处
《林产化学与工业》
EI
CAS
CSCD
2005年第4期26-30,共5页
Chemistry and Industry of Forest Products
基金
国家重点基础研究"973计划"资助项目(G1998051201)
广东省科技计划资助项目(2003C20405)
