UPLC-Q-TOF-MS/MS-linked bioactivity-guided elucidation of tissue-specific chemical diversity in Tamarix...

Tamarix austromongolica (TA), an endemic salt-tolerant tree species in northwestern China, remains largely unexplored in terms of its phytochemical composition. In this study, an untargeted metabolomics approach based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS), combined with multivariate statistical analysis, was employed for the first time to systematically characterize the metabolite profiles of six TA parts, namely roots, barks, stems, flowers, seeds, and leaves. A total of 105 metabolites belonging to 20 structural classes were identified, among which flavonoids accounted for 33% of the total metabolite pool. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) revealed significant tissue-specific distribution patterns of metabolomes across the six parts, with flavonoids identified as the core chemical markers driving inter-tissue differentiation. Parallel in vitro anti-inflammatory screening of extracts from the six parts demonstrated that the leaf extract (TAL) possessed the highest safety margin and potent NO inhibitory activity. Network pharmacology and molecular docking analyses indicated that three major flavonoids in TAL-Tricin, Quercetin-3-O-β-d-glucuronide (Q3GA), and Diosmetin-could form high-affinity complexes with MAPK3, a key target in the PI3K-Akt/NF-κB signaling pathway, and molecular dynamics simulations further validated the binding stability of these complexes. This study provides systematic analytical method support and a scientific basis for the phytochemical characterization, bioactive part screening, and quality marker discovery of TA.