Acarbose

p-Nitrophenyl palmitate, p-nitrophenyl α-d-glucopyranoside (p-NPG), pancreatic lipase, orlistat, acarbose and 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) were all purchased from Shanghai Macklin Biochemical Technology Co., Ltd., Shanghai, China. α-Glucosidase, gallic acid, rutin, ginsenoside Re, vitamin C and anhydrous glucose were obtained from Shanghai Yuanye Biotechnology Co., Ltd., Shanghai, China. Folin–Ciocalteu reagent was purchased from Sangon Bioengineering (Shanghai) Co., Ltd., Shanghai, China. The total antioxidant (FRAP) kit was purchased from Nanjing Jiancheng Biological Engineering Research Institute Co., Ltd., Nanjing, China. The rest of the chemicals, reagents, consumables and culture media were purchased from National Pharmaceutical Chemical Reagent Co., Ltd., Shanghai, China.

Wild rice Z. latifolia was collected from Jiangling County, Jingzhou City, Hubei Province, China (30°13′10″ N; 112°34′5″ E), in September 2017. The sample was obtained by manually harvesting mature plant tassels, drying and then dehulling them to obtain the seeds. The seeds were ground to a fine powder in a mechanical grinder and then sieved through a 0.45 mm sifter.
(+)-Catechin (C), (−)-epicatechin (EC), and (−)-epigallocatechin (EGC), DPPH (2,2-diphenyl-1-picrylhydrazyl), α-glucosidase (type I, from Saccharomyces cerevisiae), and pancreatic lipase (type II, from porcine pancreas) were purchased from Sigma-Aldrich Chemical Co., (St. Louis, MO, USA). Ascorbic acid, acarbose, and orlistat were obtained from Macklin Biochemical Co., Ltd. (Shanghai, China). Phloroglucinol was from Aladdin Reagents Co., Ltd. (Shanghai, China). HPLC and LC–MS grade solvents were bought from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). The D101 macroporous resin and Sephadex LH-20 were from Solarbio Science & Technology Co., Ltd. (Beijing, China) and GE Healthcare Bio-Sciences AB (Uppsala, Sweden), respectively. Precoated silica gel plates (GF254, Qingdao Marine Chemical Co., Ltd., Qingdao, China) were used for thin layer chromatography (TLC) analysis, and spots were visualized by spraying with anisaldehyde-sulfuric acid agent.

Standard gallic acid, ethyl gallate, quercetin, and myricitrin compounds were purchased from Chengdu DST Biotechnology Co., Ltd. (Chengdu, China). The molecules 7-O-galloyltricetiflavan and gallocatechin-7-gallate were isolated from A. clypearia in our laboratory. Salmonella (CMCC 50115), Bacillus subtilis (ATCC 6633), Klebsiella pneumoniae (ATCC 13883), Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853) were supplied by the Guangdong Microbial Culture Collection Center. α-Glucoside (S10050-100UN), α-amylase (S31320-50k), and p-nitrophenyl-d-glucopyranoside were purchased from Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China). Soluble starch was purchased from Damao Chemical Reagent Factory (Tianjin, China), 3,5-Dinitrosalicylic acid was provided by Solabao Biotechnology Co., Ltd. (Shanghai, China), and acarbose was obtained from Macklin Biochemical Technology Co., Ltd. (Shanghai, China). Ethanol, petroleum ether, dichloromethane, ethyl acetate, and n-butanol were purchased from Zhiyuan Chemical Reagent Co., Ltd. (Tianjin, China). Ultrapure water was prepared using a Milli-Q water purification system (Millipore, Bedford, MA, USA).