title: An ultrafiltration high-performance liquid chromatography coupled with diode array detector and mass spectrometry approach for screening and characterising tyrosinase inhibitors from mulberry leaves.
abstract: Tyrosinase is a key enzyme in melanin synthesis. Its inhibitor may be used to efficiently treat hyperpigmentation and widely applied in cosmetic products and food supplements. In the present study, a new assay based on ultrafiltration high-performance liquid chromatography coupled with diode array detector and mass spectrometry (HPLC-DAD-MS) was developed for the rapid screening and identification of ligands for tyrosinase. Experiments were carried out to select the optimal binding conditions, tyrosinase concentration, and incubation time. Non-specific binding to the denatured tyrosinase was also investigated. Twelve compounds with tyrosinase binding activity were found in mulberry leaf extracts. The identities of these compounds were characterised by HPLC-DAD-MS(n). Particularly, two compounds, namely, quercetin-3-O-(6-O-malonyl)-β-D-glucopyranoside and kaempferol-3-O-(6-O-malonyl)-β-D-glucopyranoside, were identified as new tyrosinase inhibitors. The screening results were verified by tyrosinase inhibition assays. Experimental results proved that the proposed method could rapidly screen tyrosinase inhibitors in complex mixtures.
authors.affiliation: Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Yang
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lijuan
authors.initials: L
authors.lastname: Sun
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiumei
authors.initials: X
authors.lastname: Gao
authors.forename: Yiyu
authors.initials: Y
authors.lastname: Cheng
mesh_terms: D000363:Agaricales / Q000201:enzymology*; D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000379:methods; D055808:Drug Discovery / Q000191:economics; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013058:Mass Spectrometry / Q000191:economics / Q000379:methods; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D031625:Morus / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D011485:Protein Binding; D014462:Ultrafiltration
chemical_list: D004791:Enzyme Inhibitors; D014442:Monophenol Monooxygenase