2.1. Chemicals and Reagents

Methanol, ethyl acetate, n−butanol, dichloromethane, petroleum ether, and ethanol were of analytical grade and purchased from Fuyu Fine Chemical Co., Ltd. (Tianjin, China). α−Glucosidase (from yeast), phosphate−buffered saline (PBS), and streptozotocin (STZ) were purchased from Sigma−Aldrich (St Louis, MO, USA). Na₂CO₃, 4−nitrophenyl α−D−galactopyranoside (PNPG), acarbose, and TBST buffer were obtained from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). Bicinchoninic acid (BCA) protein assay kit was purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing China). Pre−stained protein marker was obtained from New Cell & Molecular Biotech Co., Ltd. (Suzhou, China). RAC−alpha serine/threonine−protein kinase (AKT1), peroxisome proliferator−activated receptor gamma (PPARG), prostaglandin G/H synthase 2 (PTGS2), β−actin, and HRP−conjugated Affinipure Goat Anti−Mouse IgG (H + L) were purchased from Proteintech Group, Inc. (Rosement, PA, USA).