Abstract: Objective To identify the bioactive components in Jinhua Qinggan granules (JHQGs) that interact with the PACT protein in order to provide references for the development of antiviral drugs. Methods High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to detect the blood components of JHQGs. A CM5 chip blank control group and JHQG group were set up. The PACT protein was immobilized on the CM5 chip, and surface plasmon resonance (SPR) technology was used for the fishing and recovery of JHQGs with the PACT protein chip. Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was used to identify the components in the recovered samples and detect the bioactive components in JHQGs that could specifically bind to the PACT protein. Molecular docking was performed on the identified components to evaluate binding energies. Results A total of 14 bioactive components were identified out of JHQGs. In the positive ion mode, six active components were identified, namely glycyrrhetinic acid, puerarin, baicalein, formononetin, vitexin, and 6-O-methylwogonoside. In the negative ion mode, eight active components were identified, namely artemetin, 3α-hydroxyglycyrrhetinic acid, baicalin, genistein, (-)-MenthylO-Beta-D-Glucoside, catechin, paeoniflorin, and licoflavone A. Among them, the four components with stronger binding affinity to the PACT protein were baicalin, glycyrrhetinic acid, paeoniflorin, and licoflavone A, with binding affinities of -7.1, -6.9, -6.6, and -6.5, respectively. Conclusion For the first time, the PACT protein chip combined with UPLC-Q-TOF-MS has been effectively used to identify the ligand compounds in JHQGs that bind to PACT protein, suggesting that the PACT protein could serve as a potential target for the anti-respiratory viral activity of JHQGs.

Key words: Jinhua Qinggan Granules, Active Components, Anti-Respiratory Virus, PACT Protein, Target, Ligand Comp-ounds