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

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.