Ren Lingling, Xue Xingya, Zhang Feifang, Xu Qing, Liang Xinmiao
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
J Sep Sci. 2007 Apr;30(6):833-42. doi: 10.1002/jssc.200600246.
RP-HPLC is the main method for the analysis of alkaloids. However, peak tailing is a problem that commonly occurs in the separation of alkaloids. In order to overcome this, three kinds of RP columns were compared for the analysis of protoberberine alkaloids in Coptidis Rhizoma and Phellodendri Cortex in this work. XTerra MS C18 column was the best one which gave the best symmetry factor under the same conditions. With this column, a good separation of the crude extracts of C. Rhizoma and P. Cortex was achieved using 0.1% v/v formic acid buffer and methanol as mobile phase. At the same time, the crude extracts of C. Rhizoma and P. Cortex were analyzed by the LC-ESI-MSn and LC-atmospheric pressure chemical ionization (APCI)-MSn methods. In the analysis of HPLC-ESI/MSn, structures of five protoberberine alkaloids were elucidated, compared to authentic standards, and data from the literature. At the same time, the structure of a novel compound was elucidated. In the HPLC-APCI/ MSn analysis, there was an interesting phenomenon that the relative abundance of the ions M+ and [M + 2]+ was different for different alkaloids. The possible fragmentation pathways of protoberberine alkaloids in APCI/MS analysis were studied for the first time in the present work.
反相高效液相色谱法（RP-HPLC）是生物碱分析的主要方法。然而，峰拖尾是生物碱分离中常见的问题。为了克服这一问题，本研究比较了三种反相柱用于分析黄连和黄柏中的原小檗碱型生物碱。XTerra MS C18柱是最佳选择，在相同条件下其对称因子最佳。使用该柱，以0.1%（v/v）甲酸缓冲液和甲醇为流动相，实现了黄连和黄柏粗提物的良好分离。同时，采用液相色谱-电喷雾电离多级质谱（LC-ESI-MSn）和液相色谱-大气压化学电离多级质谱（LC-APCI-MSn）方法对黄连和黄柏的粗提物进行了分析。在HPLC-ESI/MSn分析中，与标准品及文献数据相比，阐明了5种原小檗碱型生物碱的结构。同时，阐明了一种新化合物的结构。在HPLC-APCI/MSn分析中，出现了一个有趣的现象，即不同生物碱的离子M+和[M + 2]+的相对丰度不同。本研究首次对APCI/MS分析中原小檗碱型生物碱可能的裂解途径进行了研究。
