Hyperoside

The chemical reference standards isoquercitrin, luteolin, naringenin, and kaempferol were provided by Chengdu Herbpurify biotechnology CO., LTD (Chengdu, China); Phlorizin, Phloretin, and Trilobatin were purchased from Sichuan Wei Keqi Biotechnology Co., Ltd (Sichuan, China); eriodictyol and hyperoside were provided by Chengdu Push biotechnology CO., LTD (Chengdu, China); quercetin and apigenin were provided by Chengdu Alfa biotechnology CO., LTD (Chengdu, China); baicalein and wogonin were obtained from Chengdu Desite biotechnology CO., LTD (Chengdu, China). The purities of all chemical reference standards were above 98% by HPLC-DAD.
Acetonitrile and methanol of chromatography grade were provided by MERCK (Darmstadt, Germany); The ultrapure water was produced by a milli-Q water purification system (Millipore, Milford, MA, United States); formic acid of LC-MS grade and all other reagents of analytical grade were purchased from Aladdin Industrial Corporation.
P. freyniana was collected from Tong-Dao country of Huaihua (109.86 longitude, 26.03 latitude), Hunan province and were identified by Professor Wei Cai (Hunan Provincial Key Laboratory of Dong Medicine, Hunan University of Medicine). The voucher specimen was deposited at School of Pharmaceutical Sciences, Hunan University of Medicine.

Liquid chromatography (LC)-grade methanol, acetonitrile, and formic acid were purchased from Merck (Darmstadt, Germany). Ultra-pure water (18.2 MΩ · cm) was prepared using a Milli-Q system (Millipore, Bedford, MA, USA). The reference standards of apigenin, kaempferol, luteolin, myricetin, quercetin, taxifolin, puerarin, vitexin, astragaline, hyperoside, isoquercitrin, kaempferol-3-O-rutinoside, rutin, gallic acid, epicatechin, (-)-gallocatechin, (-)-epigallocatechin, epigallocatechin gallate, (-)-gallocatechin gallate, (-)-epicatechin gallate, procyanidin B1, procyanidin B2, protocatechuic acid, trans-p-coumaric acid, caffeic acid, quinic acid (QA), chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, caffeine, theobromine, L-theanine, hesperidin, and the internal standard (IS) daidzein were purchased from Chengdu Push Bio-technology Co., Ltd. (Chengdu, China). The purities of the above references were higher than 98%.