Composition and Activity Analysis of Alcohol Extract of Quezui Tea Based on UHPLC−Q−Orbitrap HRMS

To explore its active ingredients, this paper analyzed its alcohol extract based on UHPLC−Q−Orbitrap HRMS, and further studied its antioxidant activity and tyrosinase inhibitiory activity. The results showed that 1321 metabolites were identified from the alcohol extract, of which 1085 metabolites, including 11 superclasses were matched to the human metabolic database(HMDB). The high content of the active metabolites such as phenylpropanoids and polyketides include neoliquiritin, quercetin 3−arabinoside, acenocoumarol, quercetin 3−O−glucoside, epicatechin−(2β→7, 4β→8)−epicatechin−(4β→8)−epicatechin, organoheterocyclic compounds include caffeine, nucleosides, nucleotides, and analogues include vidarabine, as well as caffeyl compounds include quercetin 3−O−glucoside, 3−O−feruloylquinic acid, chlorogenic acid, and 2−O−caffeoylarbutin. In addition, the scavenging rates of DPPH·, ABTS⁺·, and ·OH of the Quezui tea alcohol extract can reach 93.56%, 99.04%, and 94.82%, respectively. And the total reduction capacity increased with the increase of the total polyphenols concentration of alcohol extract, and the effect was very close to the positive control ascorbic acid. The inhibition rates of monophenolase and diphenolase were 81.50% and 58.58%, respectively.