Evaluation of the Utilization Value of Different Germplasm of Lonicera japonica Thunb Branches and Leaves Based on Phenolic Acid Components

The branches and leaves of 8 varieties of Lonicera japonica as materials, a high-performance liquid chromatography detection method for 8 phenolic acid components was established to determine the content characteristics of phenolic acids in the samples. The content determination results were evaluated by multivariate statistical methods such as cluster analysis, factor comprehensive analysis, and partial least squares discriminant analysis (PLS-DA). The results indicated that the established method for determining the content of 8 phenolic acids in the branches and leaves of L. japonica was stable, reliable and simple. The variation range of phenolic acids total content in the branches and leaves of 8 varieties of L. japonica was 19.4162~33.6684 mg·g⁻¹, and 40.9900~80.3068 mg·g⁻¹, respectively. The total content of phenolic acids varied greatly among different varieties, with 'Beihua No.1' had the highest total content in both branches and leaves, and 'Juhua No.1' had the lowest total content. Cluster analysis found that among the branches of 'Beihua No.1' was clustered separately into one group, with higher content of each component than other varieties. Factor comprehensive analysis showed that the comprehensive score of 'Beihua No.1' was >1. PLS-DA analysis identified isochlorogenic acid A, isochlorogenic acid C, ferulic acid and chlorogenic acid as the main components that might cause differences in phenolic acid content in branches. Among leaves, 'Beihua No.1' and 'Jiufeng No.1' were clustered into one category, and their comprehensive factor analysis scores were both greater than 1. PLS-DA analysis identified chlorogenic acid, caffeic acid and ferulic acid as the main components that might cause differences in phenolic acid content in leaves. In summary, there were differences in the main phenolic acid composition characteristics of different varieties. In terms of phenolic acid content, the branches and leaves of 'Beihua No.1' and 'Jiufeng No.1' have more advantages. This study provides a scientific basis for the utilization of L. japonica branches and leaves.