淡豆豉异黄酮苷及其苷元的电喷雾离子阱质谱分析

Electron spray ion trap mass spectrometry of isoflavones and isoflavone aglycones of Semen Sojae Praeparatum

目的应用电喷雾离子阱质谱(ESI-MS)技术对3种淡豆豉异黄酮苷及其苷元进行质谱裂解分析,通过主要特征碎片离子研究其裂解规律。方法在正负离子检测模式下,分别对3种淡豆豉异黄酮苷及其苷元采用离子阱质谱的多级离子(ESI-MSn)碰撞裂解方式,分析异黄酮苷和苷元的特征碎片离子。结果正离子模式下从大豆苷和大豆素中获得了m/z 417、255、227、199、137、119等特征质谱峰,从黄豆苷和黄豆素中获得了m/z 447、285、270、229等特征质谱峰,从染料木素苷和染料木素中获得了m/z 433、271、253、243、215、153等特征质谱峰。负离子模式下从大豆苷和大豆素中获得了m/z 461、415、253、225、209、197等特征质谱峰,从黄豆苷和黄豆素中获得了m/z 491、445、283、268等特征质谱峰,从染料木素苷和染料木素中获得了m/z 477、269、268、225等特征质谱峰。结论在正离子模式下,大豆苷和大豆素主要通过丢失-Glu、-CO裂解和Retro Diels-Alder(RDA)裂解;黄豆苷和黄豆素主要通过丢失-Glu、-CO、-CH3而发生裂解;染料木素苷和染料木素主要通过丢失-Glu、-CO、-H2O裂解和RDA裂解。在负离子模式下,异黄酮苷生成加HCOO-的加合离子峰,大豆苷和大豆素主要通过丢失-Glu、-CO、-2CO、-CO2裂解;黄豆苷和黄豆素主要通过丢失-Glu、-H、-CH3发生裂解;染料木素苷和染料木素主要通过丢失-Glu、-H、-CO2裂解。

Objective To analyze the fragments of 3 isoflavones and their isoflavone aglycones of Semen Sojae Praeparatum by electron spray ion trap mass spectrometry （ESI-MS）, and to study the fragmentation pathway by major fragment ions. Methods Samples were fed into the instrument in the positive and negative modes, and the fragments of the samples were yielded by multi-stage ion trap mass spectrometry （ESI-MSn）. The fragment ions of isoflavones and their isoflavone aglycones were analyzed. Results In the positive mode, ion peaks m/z 417, 255, 227, 199, 137, and 119 were detected for daidzin and daidzein; m/z 447, 285, 270, and 229 for glycitin and glycitein; and m/z 433, 271, 253, 243, 215, and 153 for genistin and genistein. In negative mode, ion peaks m/z 461, 415, 253, 225, 209, and 197 were detected for daidzin and daidzein; m/z 491, 445, 283, and 268 for glycitin and glycitein; and m/z 477, 269, 268, and 225 for genistin and genistein. Conclusion In the positive mode, daidzin and daidzein are fragmented by losing -Glu and -CO and Retro Diels-Alder （RDA） reaction; glycitin and glycitein are fragmented by losing -Glu, -CO, and -CH3; genistin and genistein are fragmented by losing -Glu, -CO, -H2O and RDA reaction. In negative mode, ions fragment ／[M＋HCOO／]- is produced by isoflavone glucosides, and daidzin and daidzein are fragmented by losing -Glu, -CO, -2CO and -CO2; glycitin and glycitein are fragmented by losing -Glu, -H, and -CH3; and genistin and genistein are fragmented by losing -Glu, -H, and -CO2. 