Separation and Pancreatic Lipase Inhibitory Activity of Two Petunidin Anthocyanins from Lycium ruthenicum Murr. by Preparative Medium-Pressure Liquid Chromatography

Abstract

Two anthocyanin monomers were separated from the crude anthocyanin extract from Lycium ruthenicum Murr. (LRM) by sequential preparative medium-pressure liquid chromatography (MPLC) on microporous and gel-type resins, and their structures were identified by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and nuclear magnetic resonance (1H NMR) spectroscopy. Their inhibitory activity against pancreatic lipase was also evaluated. Results indicated that the contents of anthocyanins P1 and P2 in the purified product obtained with macroporous resin D101 were 18.22% and 30.77% and were increased to 84.16% and 81.48% after chromatography on Sephadex LH-20, respectively. P1 and P2 were identified as petunidin 3-O-rutinoside(trans-p-coumarin)-glucoside-5-O-glucoside and petunidin 3-O-rutinoside(trans-p-coumarin)-5-O-glucoside by UPLC-MS/MS and 1H NMR, respectively. Both of them showed an excellent inhibitory activity against pancreatic lipase with half maximal inhibitory concentration (IC50) of 0.250 and 0.224 mg/mL, respectively, which were much lower than that of the crude anthocyanin extract and the macroporous resin D101 purified product. This work provides a basis for further research and utilization of anthocyanins from LRM.

Keywords

• lycium ruthenicum murr.; anthocyanin; petunidin; preparative medium-pressure liquid chromatography; macroporous resin; gel-type resin