Overall level characterization method of COMT enzyme activity and application thereof

The invention discloses an overall level characterization method of COMT enzyme activity. The overall level characterization method is characterized in that daphnetin or a derivative thereof is used as a substrate, the substrate is subjected to a C-8-site methyl substitution reaction under the action of COMT enzyme and is treated by sulfotransferase and glucuronic acid hydrolase to generate an 8-O-methylated product, and the activity of the COMT enzyme in each biological sample is determined by quantitatively detecting the contents of the substrate and 8-O-methyl metabolite thereof in unit time. According to the method provided by the invention, the activity level of COMT enzyme in a living body can be represented from the overall level, daphnetin or the derivative thereof can only be converted into 8-methyl metabolite thereof, the specificity is good, and the detection accuracy is high; the detection sensitivity is good, and the safety is relatively high; and when the method is applied to a kit, the activity