新型N-苯甲酰基-脱氢枞胺衍生物的电喷雾离子阱质谱行为研究

利用电喷雾离子阱质谱(ESI-IT-MS)技术,对8个具有潜在杀菌、抗癌生物活性的三类新型N-苯甲酰基-脱氢枞胺衍生物进行了ESI质谱行为研究。结果表明,由于7位、12位及苯甲酰基上取代基的不同,三类衍生物呈现出一定的电离及碎裂特性。在(±)-ESI-MS过程中,7-肟基类衍生物(A)和12-硝基类衍生物(C)比7-羟基类衍生物(B)更易产生二聚体;A易产生[M-H_2O+H]~+,C则更易负离子化。在(+)-ESIMS/MS过程中,A中7-肟基的存在使其易产生特征离子碎裂峰[M-35+H]~+和[M-H_2O+H]~+;A的18位酰基脱水离子峰[M-H_2O+H]~+失去一分子取代苯甲腈产生系列偶数碎裂离子峰;A的7-肟基脱水离子峰[M-H_2O+H]~+失去一分子取代苯甲醛产生系列奇数碎裂离子峰。在(-)-ESI-MS/MS过程中,B比C更稳定,在较高的碰撞能作用下获得的碎裂片段较少;均可通过丢失中性分子N-取代苯甲酰基亚甲胺、取代苯甲醛或取代苯产生系列碎裂离子片段;C的强吸电子基团12-硝基及4'-硝基的存在使其丢失的中性分子易捕获电子而离子化。

Analysis of Novel N-benzoyl Dehydroabietylamine Derivatives through Electrospray Ionization Tandem Mass Spectrometry

Eight novel N-benzoyl dehydroabietylamine derivatives with potential sterilization and anticancer biological activities were analyzed through electrospray ionization tandem mass spectrometry (ESI-IT-MS). The results indicated that three types of derivatives exhibited their own typical ionization and fragmentation process, due to their different 7-and 12-substituents on the dehydroabietylamine ring and different substituents on the benzoyl ring. In (±)-ESI-MS, the dimer ions of 7-oxime derivatives (A) and 12-nitro derivatives (C) could be more readily formed than that of 7-hydroxy derivatives (B). ［M-H₂ O+H］⁺ of A was observed in the positive ion mode. C were prone to be ionized in the negative ion mode. Two typical fragmentation peaks of ［M-35+H］+ and ［M-H₂ O+H］⁺ were observed in (+) -ESI-MS/MS spectra of 7-oxime dehydroabietylamine derivatives . The ion of ［M-H₂ O+H］⁺ formed from 18-acyl of (A) could induce some even fragmentation ion peaks by loss of substituted benzonitrile. The ion of ［M-H₂ O+H］⁺ formed from 7-oxime of (A) can induce some odd fragmentation ion peaks by loss of substituted benzaldehyde. (B) showed more stability than (C) in (-)-ESI-MS/MS process. Fewer fragmentation ions of (B) were obtained even though (B) derivatives were collided with higher energy. Ion fragmentation of (B) and (C) derivatives were induced by loss of neutral molecules of N-substituted benzoyl methylene amine, substituted benzaldehyde or substituted benzene. Due to the strong electron withdrawing ability of 12 and 4-nitro of (C) derivatives, the neutral molecules lost from (C) derivatives can be ionized by capturing one electron.