Simultaneous determination of oleanolic acid and ursolic acid by RP-HPLC in the leaves of Eriobotrya japonica Lindl.
- 作者：Xiao-Hong Xu ; Qing Su ; sophia8807@yahoo.com.cn ; Zhi-He Zang
- 关键词：RP-HPLC ; Oleanolic acid (OA) ; Ursolic acid (UA) ; Triterpenic acid
- 刊名：Journal of Pharmaceutical Analysis
- 出版年：2012
- 期刊代码：pca389_20951779
- 类别：pha
- 出版时间：June, 2012
- 卷：2
- 期：3
- 页码：238-240
- 文件大小：336 K
摘要
Oleanolic acid (OA) and ursolic acid (UA) are isomeric triterpenic acids and only one methyl's position is different between them. OA and UA always exist in the same plant, so it is difficult to separate them when determining contents by RP-HPLC. In this study, a very simple mobile phase for HPLC was developed to simultaneously determine UA and OA, and the factors affecting separation were also discussed. The mobile phase is methanol: water (95:5) with flow rate 0.4 mL/min. The retention time for OA and UA was 20.58 and 21.57 min, respectively, the resolution was 1.61. The average contents of OA and UA of three Loquat leaves sets were 1.4 mg/g and 5.6 mg/g, respectively. Regarding the HPLC, we found that changing mobile phase, adjusting the pH value or adding ion-pairing agent could not affect the separation between UA and OA greatly. While adjustment of the flow rate and column temperature could improve the resolution greatly.