Abstract: Obesity is seriously harmful to human health,therefore,a variety of anti-obesity drugs and alternative therapies are in constant development.In this study,pancreatic lipase immobilized on carboxylic acid-terminated magnetic nanoparticles synthesis conditions were optimized by response surface analysis firstly.Next,pancreatic lipase inhibitors were screened and identified from Polygonum cuspidatum.At last,binding locations of different type inhibitors and complex of pancreatic lipase and colipase were predicted.The results showed that the optimal synthetic conditions were pH 7.48,PL 20.32 mg/mL and 35.40 ℃,pancreatic lipase had been successfully immobilized on magnetic nanoparticles.And after 2 weeks,the enzyme activity still remained over 80%,which can specifically screen out positive inhibitors.In addtion,the enzyme activity kept over 50% after it had been reused for five times.Altogther 6 inhibitors on pancreatic lipase had been screened out from P.cuspidatum,and 4 inhibitors were identified by LCMS/MS and mixed stantand sample.The IC50 and inhibition types were respectively emodin (72.3±2.4 μg/mL,non-competitive inhibition),resveratrol (195.5±3.6 μg/mL,mixed inhibition),physcion (168.8±3.4 μg/mL,anti-competitive inhibition) and emodin-8-O-β-D-glucose (234.3±5.2 μg/mL,non-competitive inhibition).In 4 inhibitors,resveratrol and emodin-8-O-β-D-glucose inhibitors were firstly discovered.Two binding location of different type inhibitors on pancreatic lipase and colipase complex were predicted.

Key words: Polygonum cuspidatum, obesity, pancreatic lipase inhibitor, enzyme-immobilized magnetic nanoparticles