title: Discovery of xanthine oxidase inhibitors from a complex mixture using an online, restricted-access material coupled with column-switching liquid chromatography with a diode-array detection system.
abstract: To find potential lead compounds for antigout drug discovery, an automated online, restricted-access material coupled with column-switching liquid chromatography with a diode-array detection (RAM-LC-DAD) system was developed for screening of xanthine oxidase (XO) inhibitors and their affinity rankings in complex mixtures. The system was first evaluated by analyzing a mixture of six compounds with known inhibition of XO. Nonspecific binding to the denatured XO was investigated and used as the control for screening. Subsequently, the newly developed system was applied to screening of a natural product, Oroxylum indicum extract, and four compounds which could specifically interact with XO were found and identified as oroxin B, oroxin A, baicalin, and baicalein. The results were verified by a competitive binding test using the known competitive inhibitor allopurinol and were further validated by an inhibition assay in vitro. The online RAM-LC-DAD system developed was shown to be a simple and effective strategy for the rapid screening of bioactive compounds from a complex mixture.
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: De-qiang
authors: DQ
authors: Li
authors: Jing
authors: J
authors: Zhao
authors: Shao-ping
authors: SP
authors: Li
authors: Qing-wen
authors: QW
authors: Zhang
mesh_terms: D029402:Bignoniaceae / Q000737:chemistry*; D001667:Binding, Competitive; D002851:Chromatography, High Pressure Liquid; D055808:Drug Discovery / Q000295:instrumentation / Q000379:methods*; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D009862:Online Systems / Q000295:instrumentation*; D010936:Plant Extracts / Q000737:chemistry; D011485:Protein Binding; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D014969:Xanthine Oxidase