Background: The yellow-leafgl1mutant ofLagerstroemia indicaexhibits an altered phenylpropanoid metabolism pathway compared to wild-type (WT). However, details on the metabolites associated with leaf color variation, including color-specific metabolites with bioactive constituents, are not fully understood. Methods: Chemical and metabolomics approaches were used to compare metabolite composition and antioxidant capacity between thegl1mutant and WT leaves. Results: The mutant exhibited an irregular xylem structure with a significantly lower phenolic polymer lignin content and higher soluble phenolic compounds. Untargeted metabolomics analysis identified phenolic compounds, particularly lignans, as key differential metabolites betweengl1and WT, with a significant increase in the mutant. The neolignan derivative balanophonin-4-O-D-glu was identified as a characteristic metabolite in thegl1mutant. The soluble phenolic compounds of thegl1mutant exhibited higher FRAP, ABTS, DPPH, and hydroxyl radical scavenging activity than in WT. Correlation analysis showed a positive relationship between antioxidant capacity and phenolic compounds inL. indica. Conclusions: Metabolites associated with leaf color variation in theL. indicayellow-leafgl1mutant demonstrated high antioxidant capacity, particularly in scavenging hydroxyl radicals.
Weihang Lu,Tao Chen,Cheng Shen,Denglang Zou,Juyuan Luo,Shuo Wang,Zhibo Song,Jing Jia,Yulin Li
In the present study, an efficient strategy has been established for rapid screening of potential α-glucosidase inhibitors from the waste leaves of Rheum tanguticum by activity-oriented extraction and enrichment optimization, UPLC-QTOF-MS/MS, molecular docking, and in vitro validation. With α-glucosidase inhibitory activity as the evaluation index, the extraction process was optimized by response surface methodology and the enrichment process by macroporous resins was optimized by adsorption and desorption experiments. The active flavonoids yield was 8.85 mg/g under the optimized extraction conditions. After AB-8 macroporous resins enrichment, the active flavonoids purity increased from 2.89 % to 47.6 %, a 17-fold increase, while the IC 50 of α-glucosidase reduced from 13.97 mg/mL to 412 μg/mL, a 33.9-fold reduction. Thirty-six flavonoids in the active flavonoids fraction were identified by UPLC-QTOF-MS/MS. Molecular docking screening, in vitro activity assay and multispectral approaches verification confirmed the potential of six flavonoids as novel α-glucosidase inhibitors.