title: Pre-column incubation followed by fast liquid chromatography analysis for rapid screening of natural methylglyoxal scavengers directly from herbal medicines: case study of Polygonum cuspidatum.
abstract: Methylglyoxal (MGO), a very reactive metabolite of glucose, plays a pivotal role in the pathogenesis of several chronic diseases associated with diabetes, and it has been validated as an attractive target for them. In the present study, a simple and effective method, namely pre-column incubation followed by fast high performance liquid chromatography based on superficially porous particles (shell), coupled with diode array detection and tandem mass spectrometry (UHPLC-DAD-MS(n)), was proposed for rapid and high-throughput screening of natural MGO scavengers directly from the crude extract of Polygonum cuspidatum Sieb. et Zucc, a well-known traditional Chinese medicine which was used for treatment of diabetic complications. The hypothesis is that upon reaction with MGO, the peak areas of components with MGO scavenging potency in the chromatogram will be significantly reduced or disappear, and the structural characterization could be achieved by UHPLC-DAD-MS(n) hyphenated technique. First of all, 12 compounds in P. cuspidatum were well separated within shorter time (~12 min) than previous methods and identified, and two of them, i.e. 3,5,4'-trihydroxystilbene-3-O-(6″-galloyl)-glucoside (3) and emodin-8-O-(6'-malonyl)-glucoside (8) were firstly reported ingredients. After incubation with MGO, four stilbene derivatives were demonstrated to possess potential MGO trapping activities. Furthermore, it was proved that both polydatin (piceid) and resveratrol exhibited effective MGO-trapping capacity by UHPLC analysis, and they could significantly inhibit the formation of advanced glycation end products (AGEs) in the human serum albumin (HSA)-MGO assay, indicating that they were potential candidate agents for delaying and preventing diabetic complications. Additionally, MGO trapping mechanism exploration by UHPLC-MS(n) showed that the positions 2 and 4 of the A ring of stilbene were major active sites for trapping MGO to form both mono- and di-MGO adducts, however, the glucosylation of the hydroxyl group would significantly decrease the trapping efficiency. Collectively, the current work provides a very promising method for rapid discovery of natural MGO scavengers directly from complex matrices such as herbal medicines with huge resources.
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, China. tdpharm@126.com
authors.forename: Dan
authors.initials: D
authors.lastname: Tang
authors.forename: Jia-Xiao
authors.initials: JX
authors.lastname: Zhu
authors.forename: An-Guo
authors.initials: AG
authors.lastname: Wu
authors.forename: You-Hua
authors.initials: YH
authors.lastname: Xu
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Duan
authors.forename: Zhao-Guang
authors.initials: ZG
authors.lastname: Zheng
authors.forename: Ru-Shang
authors.initials: RS
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D045468:Fallopia japonica / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry; D017127:Glycation End Products, Advanced / Q000032:analysis / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000379:methods*; D028321:Plant Preparations / Q000737:chemistry* / Q000378:metabolism*; D011765:Pyruvaldehyde / Q000032:analysis / Q000378:metabolism*; D000077185:Resveratrol; D012709:Serum Albumin / Q000737:chemistry; D013267:Stilbenes / Q000737:chemistry
chemical_list: D005960:Glucosides; D017127:Glycation End Products, Advanced; D028321:Plant Preparations; D012709:Serum Albumin; D013267:Stilbenes; D011765:Pyruvaldehyde; D000077185:Resveratrol; C058229:polydatin