Purification and Component Analysis of Total Flavonoids from Sea Buckthorn Peel Residue and Its Anti-Pancreatic Lipase

In order to clarify the inhibition of total flavonoids purified extract (TFSE) of sea buckthorn peel residue on pancreatic lipase, this research optimized the purification condition of total flavonoids crude extract (TFCE) of sea buckthorn peel residue using AB-8 macroporous resin by means of static and dynamic adsorption and desorption experiment. Ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-Q-MS) was used to analyze the component of TFSE. In addition, the inhibitory effect and types of TFSE on pancreatic lipase were explored through the method of nitrophenyl butyrate combined with enzymatic reaction kinetics. The results showed that the optimal purification conditions for AB-8 macroporous resin were a sample concentration of 2.2 mg/mL, a sample pH of 5.0, a sample volume of 140 mL, and a sample flow rate of 1.0 mL/min. The volume fraction of ethanol was 75% with the eluent being 120 mL and the elution flow rate being 1.5 mL/min. After separation and purification under these conditions, the purity of TFSE increased from 9.786% to 50.204%. The total of 39 phenolic compounds were identified from TFSE with flavonoids like rutin, catechins, and quercetin-3-O-glucoside being the main compounds. TFSE had a strong inhibition on pancreatic lipase with the IC₅₀ being 12.46 mg/mL. In addition, the inhibition type was determined to be non-competitive inhibition by using double reciprocal plot method of Lineweaver-Burk with an inhibition constant K_i being 10.21 mg/mL. TFSE has better inhibitory activity on pancreatic lipase, which is of great significance for improving the added value of sea buckthorn peel residue products.