Screening for potential alpha -Glucosidase inhibitors in Coptis chinensis franch extract using ultrafiltration LC-ESI-MS[n]

ABSTRACT

Naturally existing alpha -glucosidase inhibitors from traditional herbal medicines have attracted considerable interest to treat type 2 diabetes mellitus [T2DM]. Hundreds of herbs have been reported to have the potential to inhibit alpha - glucosidase. However, most common methods to examine the inhibitors of alpha -glucosidase are usually time-consuming. In the current study, the screening of alpha -glucosidase ligands from Coptis chinensis Franch extract was undertaken by ultrafiltration liquid chromatography coupled to electrospray ionization tandem mass spectrometry [ultrafiltration LCESI-MS[n]]. Resultantly, the enzyme inhibition studies showed that Coptis chinensis Franch extract carries the strongest alpha - glucosidase inhibitory activity among the five kinds of Chinese herbal extracts. Subsequently, five compounds that could bind to alpha -glucosidase in the Coptis chinensis Franch extract were found using ultrafiltration liquid chromatography, and their structures were identified by ESI-MS[n] to be coptisine, epiberberine, jatrorrhizine, berberine, palmatine. Cumulatively, these results were anticipated to be encouraging for applying the Coptis chinensis Franch extracts as efficient anti-diabetic drug candidates