Distribution of ursolic acid and oleanolic acid in the leaves and flowers of Erobotrya japonica and changes of triterpene acids contents in the leaves at different harvest time / 中国药学杂志

ABSTRACT

OBJECTIVE: To find out the distribution of ursolic acid and oleanolic acid in fresh leaves, fallen leaves and flowers of Eriobotrya japonica Lindl, and to explore the variation in contents of the triterpene acids in the leaves at different harvest time. METHODS: Samples were collected in the campus once every month for 12 months. Determination of ursolic and oleanolic acid was carried out by ultra-high performance liquid cromatography (UPLC) with an acquity BEH 18 column (2.1 mm × 100 mm, 1.7 μm) using methanol-water-glacial acetic acid-triethylamine (250:50:0.10:0.05) as the mobile phase. The flow rate was 0.25 mL · min-1. The detection wavelength was set at 210 nm. RESULTS: The contents of ursolic and oleanolic acids in Erobotrya japonica leaves were significantly higher compared with those in Erobotrya japonica flowers. The contents of the two triterpene acids in the fallen leaves were higher than those in the fresh leaves. The annual curves of dynamic changes of the two triterpene acids contents in Erobotrya japonica leaves showed that the total triterpene acids contents in the Erobotrya japonica leaves collected at the different time varied from 0.874% to 0.988%. CONCLUSION: The distribution of the contents of ursolic and oleanolic acid in the fresh leaves, fallen leaves and flowers was different, and there was minor variation in the contents of the two triterpene acids in fresh Erobotrya japonica leaves collected at the different harvest time. This study therefore provides evidence that the Erobotrya japonica leaves included in Chinese Pharmacopoeia (2010 edition, Volume I) can be harvested all the year round. Furthennore, the results suggest that the optimal harvesting time oi Erobotrya japonica leaves should be between pre-defoliation period and defoliation period.