Folin-Ciocalteureagent,gallic acid, catechinand otherpolyphenolicstandardswere purchasedfrom SichuanWeikeqiBiologicalTechnologyCo., Ltd. (China).1,1-Diphenyl-2-picrylhydrazyl(DPPH),2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonicacid)diammoniumsalt(ABTS),2,4,6-tris(2-pyridyl)-s-triazine(TPTZ),trolox,α-amylase,α-glucosidaseand 4-nitrophenyl-α-D-gluco-pyranoside(α-PNPG)wereobtainedfromSigma–Aldrich(USA).

Shikimic acid was obtained from Sichuan Weikeqi Biological Technology Co., Ltd. The solution used was a 0.1 M NaOH + 10 mM SA which were prepared with doubly distilled water (Millipore Milli-Q system, USA) or deuterium water (D2O) (Cambridge Isotope Laboratories Inc., Shanghai). All the other reagents are of analytical grade.

Quinic acid (1), shikimic acid (3), fraxin (22), eculetin (24), fraxidin (31), taxifolin (41), and quercitrin (67) were purchased from Weikeqi Standards Corporation, Sichuan, China. P-coumaric acid (98), isoferulic acid (135), and ferulic acid (136) were purchased from Shanghai Pure One Biotechnology, China. Phlorizin (61) was provided by Dr Zhao. The 4, 5-dihydroxy-7-rhamnyl-2H-chromen-2-one (44), quercetin-3-O-β-D-glucuronide (57), and 5-hydroxy-7, 8-dimethoxy-flavanone (88) were isolated from the whole plants of S. glabra, while isofraxidin-7-O-sulfate (100), and isofraxidin-7-O-α-D-glucuronide (101) were isolated from the urine collected following oral administration of isofraxidin to the author.