α glucosidase from saccharomyces cerevisiae ec 3.2.1.20

The black tea used in our experiment (Lipton – Earl Grey bergamot flavor) was purchased from a local supermarket (Stop and Shop, Framingham, MA, USA). α-Glucosidase from Saccharomyces cerevisiae (EC 3.2.1.20) as well as porcine pancreatic α-amylase (EC 3.2.1.1) were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). Unless noted, all chemicals were also purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). All solvents used were HPLC grade.

Gardenia (G. jasminoides Ellis) from the Hubei province in China was provided and characterized by Hubei HaoYSJ Biotechnology Co. Limited (Yichang, China). The voucher specimens of gardenia (No. 190925) were deposited in the College of Food Science and Technology, Huazhong Agricultural University. The α-glucosidase from Saccharomyces cerevisiae (EC 3.2.1.20) was obtained from Sigma-Aldrich (St. Louis, MO, USA). The p-nitrophenyl (pNPG), α-D-glucosidase (purity > 99%), and acarbose (purity > 95%) were purchased from Yuanye Biological Technology (Shanghai, China). The AB-8 macroporous adsorption resin (0.3–1.25 mm particle size) was purchased from Nankai Hecheng Science & Technology Co. (Tianjin, China). The crocin I and geniposide (HPLC grade) were purchased from Shanghai Yuanye Biotechnology Co. (Shanghai, China). The methanol and acetic acid (HPLC grade) were obtained from J.T. Baker Co. (Phillipsburg, NJ, USA) and Aladdin Industrial Co. (Shanghai, China), respectively. The water was purified using a Milli-Q system supplied by Millipore (Billerica, MA, USA). All the other reagents were of an analytical grade.

The analytical grade chemicals and reagents were used as such in experiments without any purification. Decibel melting point apparatus was used for checking the melting point of the synthesized compounds and are reported as uncorrected. The silica gel-precoated aluminum sheets for thin-layer chromatography (TLC) were employed to keep a vigil of the reaction progress. FT-IR (Diffuse Reflectance Method (DRS) -8000A, Shimadzu, Japan) spectrophotometer was utilized for recording infrared spectra and the Bruker Avance III, 400 MHz NMR spectrometer was employed for nuclear magnetic resonance spectra (¹H NMR, ¹³C NMR; Chemical shift δ values- ppm). α-Glucosidase from Saccharomyces cerevisiae (EC 3.2.1.20, Sigma Aldrich) and α-amylase from malt (232-588-1, HiMedia) have been used for in vitro studies.