ABSTRACT
This study aims to develop an HPLC-DAD method for simultaneous determination of 11 components(6 phenolic acids and 5 iridoids) in Lonicera japonica flowers(LjF) and leaves(LjL), and compare the content differences of LjF at different development stages, LjL at different maturity levels, and between LjF and LjL. One-way ANOVA, principal component analysis(PCA), and orthogonal partial least-squares discriminant analysis(OPLS-DA) were employed to compare the content of the 11 components. The content of total phenolic acids, total iridoid glycosides, and total 11 components in LjF showed an overall downward trend with the development of flowers. The content of total phenolic acids, total iridoid glycosides, and total 11 components in young leaves were higher than those in mature leaves. The results of PCA showed that the samples at different flowering stages had distinguishable differences in component content. The VIP value of OPLS-DA showed that isochlorogenic acid A, chlorogenic acid, and secologanic acid were the main differential components of LjF at different development stages or LjL with different maturity levels. LjF and LjL have certain similarities in chemical composition while significant differences in component content. The content of total phenolic acids in young leaves was significantly higher than that in LjF at various development stages. The content of total iridoid glycosides in young leaves was similar to that in LjF before white flower bud stage. The total content of 11 components in young leaves was significantly higher than that in LjF at green flower bud stage, before and during completely white flower bud stage. LjL have great potential for development. Follow-up research on the pharmacodynamic equivalence of LjF and LjL(especially young leaves) should be carried out to speed up the development and application of LjL.