Spectronic 300 array spectrophotometer

Optical rotations were obtained with a Perkin-Elmer 341 polarimeter (Boston, MA, USA). UV spectra were measured on a Milton Roy Spectronic 300 Array spectrophotometer, and IR was recorded on a Perkin-Elmer FT-IR 1760x spectrophotometer (Boston, MA, USA). High-resolution electrospray ionization mass spectra (HR-ESI-MS) were recorded with a Bruker micro TOF mass spectrometer (Billerica, MA, USA). NMR spectra were obtained with a Bruker Avance DPX-300 FT-NMR spectrometer (Billerica, MA, USA). Vacuum liquid chromatography (VLC) and column chromatography (CC) were performed on silica gel 60 (Merck, 70–230 µm, Darmstadt, Germany), silica gel 60 (Merck, 230–400 nm) or Sephadex LH-20 (Pharmacia, Piscataway, NJ, USA). Yeast α-glucosidase enzyme, p-nitrophenol-α-d-glucopyranoside, pancreatic lipase, and 4-methylumbelliferyl oleate were purchased from Sigma Chemical, Inc. (St. Louis, MO, USA), and acarbose from Fluka Chemical (Buchs, Switzerland).

UV spectra were measured on a Milton Roy Spectronic 300 Array spectrophotometer, and the IR was recorded on a Perkin-Elmer FT-IR 1760x spectrophotometer (Boston, MA, USA). High-resolution electrospray ionization mass spectra (HR-ESI-MS) were recorded with a Bruker micro TOF mass spectrometer (Billerica, MA, USA). NMR spectra were obtained with a Bruker Avance DPX-300 or Avance III HD 500FT-NMR spectrometer (Billerica, MA, USA). MeOH, EtOAc, n-butanol, hexane, CH₂Cl₂, yeast α-glucosidase, p-NPG, glucose oxidase (GO) assay kit, sodium dodecyl sulfate (SDS), 3-(4,5- dimethyl thiazol-2-yl)-5-diphenyl tetrazolium bromide (MTT), and acarbose were obtained from Sigma-Aldrich (St. Louis, MO, USA). Alpha minimal essentialmedium (α-MEM), fetal bovine serum (FBS), and penicillin-streptomycin (10,000 IU/mL) were purchased from Thermo Fisher Scientific (Grand Island, NY, USA). Insulin (100 IU/mL) was acquired from Biocon (Bangalore, India). Silica gel (SiO₂) and TLC plates were obtained from Merck (Darmstadt, Germany), and Sephadex LH-20 was from Pharmacia (Piscataway, NJ, USA).

UV spectra were recorded on a Milton Roy Spectronic 300 Array spectrophotometer (Rochester, Monroe, NY, USA), and IR spectra were obtained on a Perkin-Elmer FT-IR 1760X spectrophotometer (Norwalk, Fairfield, CT, USA). Optical rotation was measured on a Perkin-Elmer 341 polarimeter (Norwalk, Fairfield, CT, USA). Mass spectra were recorded on a Bruker micro TOF mass spectrometer (ESI-QqTOF-MS) (Manchester, UK). NMR spectra were recorded on a Bruker Avance DPX-300 FT-NMR spectrometer or a Bruker Avance III HD 500 NMR spectrometer (Rheinstetten, Germany). Column chromatography (CC) was performed on silica gel 60 (Kieselgel 60, 70–320 µm, Merck, Darmstadt, Germany), silica gel 60 (Kieselgel 60, 230–400 µm, Merck, Darmstadt, Germany), C-18 (Kieselgel 60 RP-18, 40–63 µm, Merck, Darmstadt, Germany), Diaion HP (Mitsubishi Chemical, Tokyo, Japan) and Sephadex LH-20 (25–100 µm, GE Healthcare, Göteborg, Sweden).