Analytical grade organic solvents were utilized for grape pomace extraction and open column chromatography, while HPLC grade methanol (Fisher Scientific, Atlanta, GA, USA) and de-ionized water from Milli-Q Integral Water Purification System (EMD Millipore, Gibbstown, NJ, USA) were used for HPLC analysis. Intestinal acetone powders from rat and 4-nitrophenyl-α-D-glucopyranoside (pNPG) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Acarbose was obtained from LKT Laboratories, Inc. (St. Paul, MN, USA). HP-20 Diaion Resin Styrenic Adsorbent and silica gel 40–60 µm were purchased from Sorbent Technologies (Atlanta, GA, USA) and Acros Organics (Morris Plains, NJ, USA), respectively. TLC Silica Gel 60 F254 was acquired from EMD Millipore.
Optical rotations were recorded on a Perkin-Elmer 341 polarimeter (Perkin Elmer, Norwalk, CT, USA). Digilab Excalibur Series FTS 3000MX spectrophotometer (Digilab, Inc., Marlborough, MA, USA) was used for the measurement of IR spectrum. NMR spectra were recorded on a Varian Mercury 400 MHz instrument (Varian, Inc., Palo Alto, CA, USA). Chemical shifts are presented in δ values. J values are presented in Hz. HRESIMS of the compounds was analysed on a Waters LCT Premier High Resolution Exact Mass Spectrometer (Waters Corp., Milford, MA, USA), while EIMS analysis took place using a VG 70-250-S Mass Spectrometer (Micromass Corp., Manchester, UK).
Optical rotations were recorded on a Perkin-Elmer 341 polarimeter (Perkin Elmer, Norwalk, CT, USA). Digilab Excalibur Series FTS 3000MX spectrophotometer (Digilab, Inc., Marlborough, MA, USA) was used for the measurement of IR spectrum. NMR spectra were recorded on a Varian Mercury 400 MHz instrument (Varian, Inc., Palo Alto, CA, USA). Chemical shifts are presented in δ values. J values are presented in Hz. HRESIMS of the compounds was analysed on a Waters LCT Premier High Resolution Exact Mass Spectrometer (Waters Corp., Milford, MA, USA), while EIMS analysis took place using a VG 70-250-S Mass Spectrometer (Micromass Corp., Manchester, UK).