异黄酮同分异构体的ESI-IT-TOF质谱特征及区别

Identification and Mass Spectrometric Characterization of Isomeric Isoflavone Aglycones by ESI-IT-TOF Mass Spectrometry

采用电喷雾-离子阱-飞行时间串联质谱(ESI-IT-TOF)技术,在正/负离子检测模式下对芒柄花素及其同分异构体7甲-氧基异黄酮的质谱裂解规律进行了系统研究.实验结果表明,该化合物在正、负离子模式下均得到了5级高分辨质谱.结果显示,二者在负离子模式下的碎片相同,而在正离子模式下的碎片裂解不同.根据正负离子模式的5级高分辨质谱推导了两者的可能裂解规律,丰富了异黄酮的ESI-MSn数据,为其它异黄酮类化合物的分析鉴定提供了有效的质谱方法.

mass spectrometric method based on the combined with electrospray ionization/ion trap/time-of- flight（ESI-IT-TOF） mass spectrometer was used for systematic research of 7-methoxy-4＇-hydroxy isoflavone and formononetin. MS5 spectra both in positive and negative ion modes with a high resolution were obtained. Different product ions were observed in positive ion mode, while almost the same product ions were observed in negative ion mode. With the high selectivity of parent ions and precise formulae of each fragment, fragmentation mechanisms were proposed with a high reliability. The established method could be used for the sensitive and rapid identification of isoflavonoids.