α-Glucosidase inhibition and antioxidant activity of an oenological commercial tannin. Extraction, fractionation and analysis by HPLC/ESI-MS/MS and 1H NMR
| Autor: | Carmela Spatafora, Nunzio Cardullo, Vincenzo Cunsolo, Corrado Tringali, Vera Muccilli |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
DPPH
Plant polyphenols Oenological tannins Quercus robur a-Glucosidase inhibition HPLC/ESI-MS/MS 1H NMR Fractionation Chemical Fractionation High-performance liquid chromatography Antioxidants Analytical Chemistry chemistry.chemical_compound 0404 agricultural biotechnology Tandem Mass Spectrometry Tannin Glycoside Hydrolase Inhibitors Gallic acid Chromatography High Pressure Liquid chemistry.chemical_classification Grandinin Chromatography Polyphenols 04 agricultural and veterinary sciences General Medicine Magnetic Resonance Imaging 040401 food science chemistry Polyphenol Tannins Food Science Castalagin |
| Popis: | Two batches of the oenological tannin Tan'Activ R, (toasted oak wood - Quercus robur), were extracted with ethanol. A fractionation on XAD-16 afforded four fractions for each extract. Extracts and fractions were evaluated for antioxidant activity (DPPH), polyphenol content (GAE) and yeast α-glucosidase inhibitory activity. Comparable results were obtained for both columns, fractions X1B and X2B showing the highest antioxidant activity. Fractions X1C and X2C notably inhibited α-glucosidase, with IC50=9.89 and 8.05μg/mL, respectively. Fractions were subjected to HPLC/ESI-MS/MS and (1)H NMR analysis. The main phenolic constituents of both X1B and X2B were a monogalloylglucose isomer (1), a HHDP-glucose isomer (2), castalin (3) gallic acid (4), vescalagin (5), and grandinin (or its isomer roburin E, 6). X1C and X2C showed a complex composition, including non-phenolic constituents. Fractionation of X2C gave a subfraction, with enhanced α-glucosidase inhibitory activity (IC50=6.15μg/mL), with castalagin (7) as the main constituent. |
| Databáze: | OpenAIRE |
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