Acarbose

All of the solvents were analytical grade, of high-performance liquid chromatography-mass spectrometry (HPLC-MS) quality (>99%) and were obtained from Merck (Darmstadt, Germany). Deionized water (DIW) was used for the extractions and was of Milli-Q quality for liquid chromatography (LC) and UV-VIS spectrophotometric measurements. The delphinidin-3-O-rutinoside was purchased from Phytolab (Vestenbergsgreuth, Germany). The phenolic acid standards (protocatechuic acid, p-hydroxybenzoic acid, gallic acid, gentisic acid, vanillic acid, salicylic acid, syringic acid, caffeic acid, p-coumaric acid, m-coumaric acid, ferulic acid, o-coumaric acid and chlorogenic acid) were purchased from Sigma-Aldrich (Poole, Dorset, UK). The acarbose was purchased from J&K (Beijing, China), α-Amylase solution from Sigma Aldrich (Steinheim, Germany), 3,5-dinitrosalicylic acid (DNS) from Fluorochem (Hadfield, UK) and Na-K tartrate tetrahydrate (p. A.) from Chemsolute (Roskilde, Denmark). All of these pure standards were used for identification and quantification purposes.

Sucrase and maltase were obtained from the intestinal brush border of Wistar rats [31 (link)]. (Institute of Laboratory Animal Science, CAMS & PUMC, Beijing, China, approved number: No. 00001042). α-Amylase, DAB, and miglitol were purchased from Sigma-Aldrich (St. louis, MO, USA), FA was purchased from MedChem Express (Nanjing, China), SZ-A and 1-DNJ were provided by Institute of Materia Medica, Chinese Academy of Medical Sciences (the content of 1-DNJ in SZ-A was 35%), and acarbose was purchased from J&K Scientific (Beijing, China). Each stock solution was prepared with distilled water. All other solvents and chemicals were of analytical purity.

C. morifolium flowers were purchased from Tongxiang Shine Herb Health products Co., Ltd., (Jiaxing, China). The plant material was powdered and stored in a sealed bag until use. 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH), trifluoroacetic acid (TFA), 1-phenyl-3-methyl-5-pyrazolone (PMP), trichloroacetic acid (TCA), butyl hydroxyanisole (BHA), 4-nitrophenyl-β-D-glucopyranoside (pNPG), and α-glucosidase (biological reagent, 50 U/mg) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Acarbose, 1,10-phenanthroline, bovine serum albumin (BSA), and monosaccharide standards (glucose, fructose, rhamnose, galactose, xylose, arabinose) were purchased from J & K Scientific Co., Ltd. (Beijing, China). All other chemicals used were of analytical grade.