A novel sample preparation and on-line HPLC-DAD-MS/MS-BCD analysis for rapid screening and characterization of specific enzyme inhibitors in herbal extracts: case study of α-glucosidase.
Drug discovery from complex mixture like Chinese herbs is a challenge and extensive false positives make the obtainment of specific bioactive compounds difficult. In the present study, a novel sample preparation method was proposed to rapidly reveal the specific bioactive compounds from complex mixtures using α-glucosidase as a case. Firstly, aqueous and methanol extracts of 500 traditional Chinese medicines were carried out with the aim of finding new sources of α-glucosidase inhibitors. As a result, the extracts of fruit of Terminalia chebula (FTC), flowers of Rosa rugosa (FRR) and Eugenia caryophyllata (FEC) as well as husk of Punica granatum (HPG) showed high inhibition on α-glucosidase. On-line liquid chromatography-diode array detection-tandem mass spectrometry and biochemical detection (HPLC-DAD-MS/MS-BCD) was performed to rapidly screen and characterize α-glucosidase inhibitors in these four extracts. After tentative identification, most of compounds with inhibitory activity in the investigated crude extracts were found to be tannins commonly recognized as non-specific enzyme inhibitors in vitro. Subsequently, the four extracts were treated with gelatin to improve specificity of the on-line system. Finally, two compounds with specific α-glucosidase inhibition were identified as corilagin and ellagic acid. The developed method could discover specific α-glucosidase inhibitors in complex mixtures such as plant extracts, which could also be used for discovery of specific inhibitors of other enzymes.
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
D Q
DQ
Li
J
J
Zhao
J
J
Xie
S P
SP
Li
D002851:Chromatography, High Pressure Liquid; D055808:Drug Discovery; D004610:Ellagic Acid / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000032:analysis*; D035264:Flowers / Q000737:chemistry; D005780:Gelatin / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry; D047348:Hydrolyzable Tannins; D007700:Kinetics; D029561:Lythraceae / Q000737:chemistry; D008516:Medicine, Chinese Traditional; D010936:Plant Extracts / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D028321:Plant Preparations / Q000032:analysis*; D015203:Reproducibility of Results; D027826:Rosa / Q000737:chemistry; D027842:Syzygium / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D013634:Tannins / Q000737:chemistry; D029766:Terminalia / Q000737:chemistry; D000520:alpha-Glucosidases / Q000032:analysis*
D004791:Enzyme Inhibitors; D005960:Glucosides; D047348:Hydrolyzable Tannins; D010936:Plant Extracts; D028321:Plant Preparations; D013634:Tannins; D004610:Ellagic Acid; C049096:corilagin; D005780:Gelatin; D000520:alpha-Glucosidases
Corilagin; Ellagic acid; LC–DAD–MS/MS–BCD; α-Glucosidase inhibitors