title: Identification of tyrosinase specific inhibitors from Xanthium strumarium fruit extract using ultrafiltration-high performance liquid chromatography.
abstract: In this study, a strategy based on ultrafiltration-high performance liquid chromatography coupled with diode array detection (UF-HPLC-DAD) was proposed for screening tyrosinase specific inhibitors in Xanthii fructus. The false negatives were distinguished by optimizing the UF-HPLC-DAD parameters to reduce the background noise; the false positives were distinguished by introducing a blocked tyrosinase in the control group for comparison. To obtain the best blocker, the competitive experiments were performed using various known ligands. Using this strategy, three competitive inhibitors (protocatechuic acid; 3,5-di-O-caffeoylquinic acid; and 1,5-di-O-caffeoylquinic acid) and one mixed-type inhibitor (chlorogenic acid) were identified. These results were verified using tyrosinase inhibition assay, kinetic analysis, and structural simulation of the complex. Our experimental results suggest that the proposed strategy could be useful for high-throughput identification of tyrosinase specific inhibitors in natural products.
authors.affiliation: Department of Food Science and Nutrition, Hallym University, Chuncheon 200-702, South Korea; Institute of Korean Nutrition, Hallym University, Chuncheon 200-702, South Korea.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Food Science and Nutrition, Hallym University, Chuncheon 200-702, South Korea; Institute of Korean Nutrition, Hallym University, Chuncheon 200-702, South Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Hwang
authors.affiliation: College of Food Science and Engineering, Liaoning Medical University, Jinzhou 121-000, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Food Science and Nutrition, Hallym University, Chuncheon 200-702, South Korea; Institute of Korean Nutrition, Hallym University, Chuncheon 200-702, South Korea; Institute of Natural Medicine, Hallym University, Chuncheon 200-702, South Korea. Electronic address: limss@hallym.ac.kr.
authors.forename: Soon Sung
authors.initials: SS
authors.lastname: Lim
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D014462:Ultrafiltration / Q000379:methods*; D031210:Xanthium / Q000737:chemistry*
chemical_list: D004791:Enzyme Inhibitors; D014442:Monophenol Monooxygenase
keywords: Binding affinity; HPLC; Tyrosinase inhibitor; Ultrafiltration; Xanthium strumarium