Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang 310008, People's Republic of China.
Clinical Laboratory of Integrative Medicine, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, People's Republic of China.
J Agric Food Chem. 2020 Oct 28;68(43):12164-12172. doi: 10.1021/acs.jafc.0c03952. Epub 2020 Oct 19.
Fresh green tea (GT) is commonly considered to have better sensory flavor and higher commercial value than long-term-stored GT; however, the chemical variations during storage are unclear. In this study, the chemical profiles of stored GT were surveyed among time-series samples from 0 to 19 months using a nontargeted metabolomics method. Seven -ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) increased from 0.022 ± 0.019 to 3.212 ± 0.057 mg/g within 19 months (correlation coefficients with storage duration ranging from 0.936 to 0.965), and they were the most significantly increased compounds among the 127 identified compounds. Two representative EPSFs (-EGCG-cThea and -EGCG-cThea) possess potential anti-inflammatory properties by suppressing the expression, phosphorylation, and nuclear translocation of nuclear factor kappa-B (NF-κB) p65 in lipopolysaccharide-stimulated macrophages based on western blotting and immunofluorescence results. In conclusion, EPSFs were found to be marker compounds for stored GT and showed potential anti-inflammatory activity by regulating the NF-κB signaling pathway.
新鲜绿茶（GT）通常被认为具有更好的感官风味和更高的商业价值，而长期储存的 GT 则不然；然而，其在储存过程中的化学变化尚不清楚。在这项研究中，使用非靶向代谢组学方法，对从 0 到 19 个月的时间序列样本中储存的 GT 的化学特征进行了调查。七种 -乙基-2-吡咯烷酮取代的黄烷-3-醇（EPSF）在 19 个月内从 0.022±0.019 增加到 3.212±0.057mg/g（与储存时间的相关系数范围为 0.936 至 0.965），在鉴定出的 127 种化合物中，它们是增加最显著的化合物。两种代表性的 EPSF（-EGCG-cThea 和 -EGCG-cThea）通过抑制脂多糖刺激的巨噬细胞中核因子 kappa-B（NF-κB）p65 的表达、磷酸化和核易位，具有潜在的抗炎特性，基于 Western blot 和免疫荧光结果。总之，EPSF 被发现是储存 GT 的标记化合物，并通过调节 NF-κB 信号通路显示出潜在的抗炎活性。
