Identification and screening of potential anti-pneumonia active ingredients and targets of Qing-Kai-Ling oral liquid via UHPLC-Q-Exactive Orbitrap mass spectrometry based on data post-processing

•An UHPLC-Q-Exactive Orbitrap mass spectrometry method was established. A total of 150 compounds were identified, including 35 amino acids and their derivatives, 36 organic acids, 20 terpenids, 20 alkaloids, 12 glycosides, 7 flavonoids and 20 others.•The rationality of the cracking reaction of the compound was explored and verified by molecular simulation calculation based on DFT, and the structure of the compound was further confirmed.•The potential mechanism of anti-pneumonia action of Qing-Kai-Ling oral liquid was studied by means of network pharmacology. A total of 90 key targets were screened, and several major signaling pathways of PI3K-AKT, MAPK and TNF were focused on. Qing-Kai-Ling oral liquid is commonly used clinically for the treatment of fever and upper respiratory tract infection. Moreover, studies have shown that Qing-Kai-Ling oral liquid has an anti-pneumonia effect. However, owing to its complex pharmacodynamic material basis, its pharmacological research and clinical application are limited. To address this problem, the chemical constituents of Qing-Kai-Ling oral liquid were identified by ultra-high performance liquid chromatography quadrupole-Exactive Orbitrap mass (UHPLC-Q-Exactive Orbitrap MS) and network pharmacology methods, which were used to predict its potential anti-pneumonia target and signalling pathway. A total of 150 compounds were identified and tentatively characterized, including 35 amino acids and their derivatives, 36 organic acids, 20 terpenoids, 20 alkaloids, 12 glycosides, 7 flavonoids, and 20 others. Among them, 14 compounds were accurately identified by comparing their retention time and mass spectrum data with those of reference substances. Additionally, we performed molecular simulation calculations via Density Function Theory to determine the plausibility of the compound cleavage reactions and further confirm compound structures. Furthermore, 90 key targets were screened through network pharmacology, with the particular focus on the PI3K-AKT, MAPK and TNF signalling pathways. This method achieved the first comprehensive identification of the chemical composition of Qing-Kai-Ling oral liquid and elucidated its potential mechanism of anti-pneumonia. The results provide valuable reference and data support for pharmacodynamic substance research and quality control.