Health and Environment Department, Environmental Resources & Technologies, Austrian Institute of Technology, A-2444 Seibersdorf, Austria.
Food Funct. 2010 Dec;1(3):262-8. doi: 10.1039/c0fo00085j. Epub 2010 Nov 18.
In order to provide some insight into the chemical basis for the antioxidant behaviour of bitter tea, the Chinese medicinal beverage derived from leaves of Ilex kudincha or Ilex latifolia, free radicals generated during the oxidation of aqueous extracts of dried leaves have been investigated by electron paramagnetic resonance (EPR) spectroscopy. With both beverages, the major components in the EPR spectra after accelerated autoxidation under alkaline conditions or oxidation with the superoxide anion radical were comparable to those derived from reactions of caffeoylquinic acids. Thus these reaction products have sufficient stability for biological activity, and the present results suggest that such molecules contribute appreciably to the antioxidant chemistry of these beverages.
为了深入了解苦丁茶抗氧化行为的化学基础，这种中国药用饮料是由枸骨冬青或苦丁冬青的叶子制成的，我们通过电子顺磁共振波谱法（EPR）研究了在加速碱氧化或超氧阴离子自由基氧化过程中，干茶叶水提物中产生的自由基。在加速碱氧化或用超氧阴离子自由基氧化后，两种饮料的 EPR 图谱中的主要成分与咖啡酰奎宁酸的反应产物相似。因此，这些反应产物具有足够的稳定性以发挥生物活性，并且本研究结果表明，此类分子对这些饮料的抗氧化化学性质有重要贡献。
