Screening ofα-glucosidase inhibitors in large-leaf yellow tea by offline bioassay coupled with liquid chromatography tandem mass spectrometry  

作　　者：You Wu Zisheng Han Mingchun Wen Chi-Tang Ho Zongde Jiang Yijun Wang Na Xu Zhongwen Xie Jinsong Zhang Liang Zhang Xiaochun Wan 

机构地区：[1]State Key Laboratory of Tea Plant Biology and Utilization,Anhui Agricultural University,Hefei 230036,China [2]International Joint Laboratory on Tea Chemistry and Health Effects of Ministry of Education,Anhui Agricultural University,Hefei 230036,China [3]Department of Food Science,Rutgers University,New Brunswick,NJ 08901,USA

出　　处：《Food Science and Human Wellness》2022年第3期627-634,共8页食品科学与人类健康（英文）

基　　金：supported by Natural Science Foundation of China(32072633,32072634,31201335);earmarked fund for China Agriculture Research System(CARS-19);Anhui Key research and development plan(1804b06020367,202004b11020004);Young Elite Scientist Sponsorship Program by National CAST(2016QNRC001)。

摘　　要：Larger-leaf yellow tea(LYT)is a characteristic type of Chinese tea produced in Huoshan County,Anhui Province,which is made by mature leaves with stems.According to recent report,LYT showed competitive effects in anti-hyperglycemia in comparison to other teas such as green or black tea.However,the bioactive compounds of LYT are still undiscovered so far.For this purpose,5 fractions of LYT were prepared by sequential extraction.The in vitro bioassay results indicated that the ethyl acetate fraction of LYT had the strongest inhibitory effects onα-glucosidase andα-amylase.Fluorescence-quenching analysis and proteinbinding test revealed that the compounds of ethyl acetate fraction could inhibitα-glucosidase andα-amylase activities through binding to enzymes or other mechanisms.All chromatographic peaks of high-performance liquid chromatography(HPLC)of ethyl acetate fraction were separated and collected.The purified compounds were identified by liquid chromatography-mass spectrometry(LC-MS),and subsequently screened by calculating their inhibition ratio onα-glucosidase at the real concentration in LYT infusion.The results showed that(-)-epigallocatechin gallate,(-)-gallocatechin gallate,caffeine,N-ethyl-2-pyrrolidone-substituted flavan-3-ols were effective inhibitors forα-glucosidase.

关 键 词：Larger-leaf yellow tea ANTI-HYPERGLYCEMIA Α-GLUCOSIDASE Mass spectrometry Separation 

分 类 号：O657.63[理学—分析化学] TS272.7[理学—化学]