Study on Quality Evaluation of Flower Buds and Leaves of <i>Lonicera japonica</i> in Saline–Alkali Soil Based on UPLC Fingerprinting and Multicomponent Content Determination

Lonicera japonica Thunb. (LJT) is a clinically used bulk traditional Chinese medicine with high adaptability to grow in saline and alkaline environments. In this study, we established a quality evaluation method for LJT (Lonicerae Japonicae Flos [LJF] and Lonicera Japonica Leaves [LJL]) in saline and alkaline environments based on ultrahigh‐performance liquid chromatography (UPLC) technology, combined with fingerprinting, multivariate statistical analysis, and determination of multicomponent content. First, the fingerprint of LJF was established by UPLC, and a total of 13 peaks were calibrated, and nine chemical components were identified. The LJL fingerprint was established, a total of 16 peaks were calibrated, and 10 chemical components were identified and evaluated for similarity. Then, multivariate statistical analyses such as cluster heat map analysis, principal component analysis (PCA), orthogonal and partial least squares discriminant analysis (OPLS‐DA) were applied to classify LJT into “Yate 1” LJT and other LJT (“Yate 2” LJT and “Yate Liben” LJT). The other LJTs are further categorized into LJF (“Yate 2” LJF and “Yate Liben” LJF) and LJL (“Yate 2” LJL and “Yate Liben” LJL). LJF was further divided into “Yate 2” LJF and “Yate Liben” LJF. Different markers between the groups were screened. Finally, the content of 11 known components in 18 batches of LJT samples was determined. Differences in the content of “Yate 1” LJF, “Yate 2” LJF, and “Yate Liben” LJF were compared by t ‐test. The results showed that the LJF content of the three varieties was significantly higher in saline than in nonsaline areas, or there was no significant difference. The quality evaluation method of saline LJT established in this study can effectively evaluate the quality of saline LJT, provide a reasonable reference for LJT cultivation in saline areas, and provide a scientific basis for the full application of different varieties of LJT herbs.