2α-羟基齐墩果酸与2α-羟基熊果酸的分离及其EI-MS(+)差异性的研究

Research on Isolation of 2α-Hydroxy-oleanolic Acid and 2α-Hydroxy-ursolic Acid and Their EI-MS(+)Differences

摘要: 采用半制备高效液相法从枇杷叶中分离了2α-羟基齐墩果酸与2α-羟基熊果酸,通过UV、电子电离质谱(EI-MS)、NMR、IR对其结构进行了确认。并对其电子电离质谱正离子(EI-MS(+))裂解途径进行了研究,通过比较不同离子碎片的稳定性,提出了利用EI-MS中m/z 248、203和133这3个特征离子碎片丰度差异鉴别这两种物质的方法。

Abstract: 2α-Hydroxy-oleanolic acid and 2α-hydroxy-ursolic acid were isolated from Eriobotrya japonica leaves by preparative reversed-phase high performance liquid chromatography. The structure was confirmed by using UV, EI-MS, NMR and IR. The possitive ion fragmentation pathway was researched by electron ionization mass spectrometry and the stability of ion fragmentation was compared. 2α-Hydroxy-oleanolic acid and 2α-hydroxy-ursolic acid were discerned by comparing the abundance of m/z 248, 203 and 133.