Screening α-glucosidase inhibitors from traditional Chinese drugs by capillary electrophoresis with electrophoretically mediated microanalysis.

In the present study, we report the study by a combination of electrophoretically mediated microanalysis method with a partial technique for screening alpha-glucosidase inhibitors from 21 traditional Chinese drugs. In the setup, substrates and enzymes were introduced into the capillary as distinct plugs, the electrophoretic conditions for enzyme reaction and separation of substrates and products were different in the composition and pH of the background electrolyte, which make more enzyme reactions possible. Part of the capillary was filled with the optimal buffer for the enzyme reaction, whereas the rest was filled with the background electrolyte optimal for the separation of substrates and products. With the optimal condition, the Michaelis-Menten constant and the inhibitive mechanism of acarbose were studied, which were in the same range as previous literature data. Furthermore, the inhibitory ratios of enzymatic activity (IRE) of 21 traditional Chinese drugs were determined. The classical method has superiorities over traditional assay methods, which not only minimizes the false-positive results but also simplifies the experimental processes. It could be used for screening inhibitors in natural extract.