Chemicals and Materials

CRP samples (Batch number: 201712) were acquired from Xinhui Hele Tea Art Co. Ltd. (Jiangmen, China), and were authenticated by Prof. Wenbo Liao from Sun Yat-sen University. Corresponding voucher specimens were kept in our laboratory. Reserpine injection was purchased from Guangdong Bangmin Pharmaceutical Co., Ltd. (Jiangmen, China). The reference standards of hesperidin, naringin, neohesperidin and rutin were obtained from National Institute for Control of Biological and Pharmaceutical Products of China (Beijing, China). Hesperetin, naringenin, nobiletin and mass spectrometry (MS) grade formic acid were purchased from Sigma-Aldrich (St. Louis, MO, United States). MS grade acetonitrile was purchased from Fisher Scientific (Pittsburgh, PA, United States). All water used was distilled and further purified by a Milli-Q system (Millipore, Milford, MA, United States). Other reagents used in the experiment were of analytical grade.