Department of Environmental Biological and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100 Caserta, Italy.
Molecules. 2020 Apr 11;25(8):1765. doi: 10.3390/molecules25081765.
Marketed green teas (GTs) can highly vary in their chemical composition, due to different origins, processing methods, and a lack of standardization of GT-based products. Consequently, biological activities become difficult to correlate to the presence/content of certain constituents. Herein, ultra-high-performance liquid chromatography (UHPLC) combined with high-resolution tandem mass spectrometry (HR MS/MS) was successfully applied to six commercial GT products, extracted by ethanol sonication, to disclose their polyphenol profile beyond the well-known catechins. The relative abundance of each class of metabolites was correlated to antiradical and antilipoperoxidant data through hierarchical clustering analysis, since it reasonably affects the beneficial properties of the product that reaches the consumer. The thiobarbituric acid reactive substances (TBARS) assay demonstrated that GT extracts effectively counteracted the UV-induced lipoperoxidation of hemp oil, which is highly rich in Polyunsaturated Fatty Acids (PUFAs), and therefore highly unstable. The Relative Antioxidant Capacity Index (RACI) comprehensively emphasized that gunpower and blend in filter GTs appeared to be the less active matrices, and except for a GT-based supplement, the Sencha GT, which was particularly rich in flavonol glycosides, was the most active, followed by Bancha GT.
市售绿茶（GT）由于来源、加工方法不同，且 GT 产品缺乏标准化，其化学成分差异很大。因此，生物活性很难与某些成分的存在/含量相关联。本研究采用超高效液相色谱（UHPLC）结合高分辨串联质谱（HR MS/MS），对 6 种市售 GT 产品进行乙醇超声提取，揭示了除儿茶素外 GT 的多酚特征。通过层次聚类分析，将各代谢物类别的相对丰度与自由基清除和抗脂类过氧化活性数据相关联，因为这合理地影响了到达消费者手中的产品的有益特性。硫代巴比妥酸反应物质（TBARS）试验表明，GT 提取物能有效抑制富含多不饱和脂肪酸（PUFAs）、高度不稳定的大麻油的 UV 诱导的脂质过氧化。相对抗氧化能力指数（RACI）全面强调，火药和过滤嘴 GT 似乎是活性较低的基质，除了富含黄酮醇糖苷的 Sencha GT 外，最活跃的是 Bancha GT。
