Comparative Analysis of Lonicera japonica Flower from Different Harvesting Periods Based on UV Fingerprint and Chemometrics / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the quality variation of Lonicera japonica flower from different harvesting periods by ultraviolet visible（UV-Vis） fingerprint combined with chemometrics. MethodTwenty-five L. japonica flower samples from five harvesting periods， including young bud stage，green bud stage，white bud stage，silver and golden flower stages， were collected， with five samples for each stage. UV-Vis fingerprints of L. japonica flower from different harvesting periods were established in the context of the optimum extraction method based on the single factor experiment. The results showed that the absorption values at 209，216，226，250，280，303，318， and 350 nm were significantly different. Moreover，after data pretreatment and normalization，multivariate statistical analyses， such as principal component analysis （PCA），partial least squares discriminant analysis （PLS-DA），and orthogonal PLS-DA （OPLS-DA）were performed by SIMCA-P+ to establish the quality variation model of L. japonicas flower from harvesting periods. ResultAs revealed by PCA and PLS-DA， L. japonicas flower samples from five harvesting periods were clustered separately and closely in a harvesting time-dependent manner， suggesting that the content of components contained in samples from different harvesting periods was highly distinct and correlated with harvesting periods. The pairwise comparison of OPLS-DA indicated that triterpenoids or volatile oils were the main components causing the changes from the young bud stage to the green bud stage，and the content of them decreased. The main components from the green bud stage to the white bud stage were triterpenoids （or iridoids），volatile oils，phenolic acids， or flavonoids，and the content of them decreased， which was consistent with the HPLC result of chlorogenic acid. From the white bud stage to the silver flower stage， the main components were iridoids （increasing in content） and triterpenoids （or volatile oils） （decreasing in content）. The main altered components from the silver flower stage to the golden flower stage were triterpenoids （or volatile oils） whose content increased. ConclusionThis method is simple and feasible， which can provide references for the quality control of Chinese medicine.