There are eight most abundant green tea catechins (GTCs) existing in four pairs of eipimers, and carbon-3 configuration represents the only steric difference within each pair. This study aimed to use a new kinetic approach to elucidate the effect of stereochemical changes on the antioxidant activity. A mixture of eight GTCs was treated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) prepared in a series of concentrations, their relative reaction rates towards scavenging DPPH were revealed by the recently introduced parameter, i.e. D_m. The 3-R configuration in (−)-epicatechin, (−)-epigallocatechin and (−)-epigallocatechin gallate gave lower D_m values demonstrating faster kinetics as opposed to their 3-S counterparts, with the only exception of the pair of (−)-catechin gallate and (−)-epicatechin gallate in which 3-S configuration was faster. These results suggested that the kinetic approach adopted in this study could reflect the different antioxidant activity of GTCs attributed by minor steric changes.

四对表异构体中存在八种最丰富的绿茶儿茶素（GTC），并且碳3构型代表每对内唯一的空间差异。这项研究旨在使用一种新的动力学方法来阐明立体化学变化对抗氧化剂活性的影响。八种GTC的混合物用一系列浓度的2,2-二苯基-1-吡啶并肼处理（DPPH）处理，它们对清除DPPH的相对反应速率通过最近引入的参数D _m揭示。（-）-表儿茶素，（-）-表没食子儿茶素和（-）-表没食子儿茶素没食子酸酯中的3- R构型给出了较低的D _m值，表明其动力学较其3- S快对应物，唯一的例外是（-）-儿茶素没食子酸酯和（-）-表儿茶素没食子酸酯对，其中3- S构型更快。这些结果表明，本研究中采用的动力学方法可能反映了由较小的空间变化引起的GTC的不同抗氧化活性。