克拉霉素及其杂质KL和KO的电喷雾串联质谱分析  

Analysis of Clarithromycin and Its Impurities KL and KO Using ESI-MS/MS

作　　者：蒋可志[1] 金勇 王兆刚 付君平 秦欣荣 侯仲轲 潘远江[1] JIANG Ke-zhi;JIN Yong;WANG Zhao-gang;FU Jun-ping;QIN Xin-rong;HOU Zhong-ke;PAN Yuan-jiang(Chemistry Department,Zhejiang University,Hangzhou 310007,China;Zhejiang Guobang Pharmaceutical Co.LTD,Shaoxing 312369,China)

机构地区：[1]浙江大学化学系,浙江杭州310007 [2]浙江国邦药业有限公司,浙江绍兴312369

出　　处：《质谱学报》2021年第1期8-15,I0001,共9页Journal of Chinese Mass Spectrometry Society

摘　　要：作为微生物次级代谢产物衍生物,克拉霉素产品存在大量杂质,需要对部分微量杂质进行进一步的结构分析。本研究采用电喷雾串联质谱(ESI-MS/MS)技术与量化计算相结合,系统地研究了克拉霉素K及其杂质KL和KO的质谱碎裂规律。发现其质子化离子在串联质谱中主要发生一系列涉及侧链基团的碎裂反应,在高质量区存在丢失CH4O、C8H(12)O3和(C8H(12)O3+CH4O),在低质量区存在丢失大环内酯单元产生特征离子m/z 158.1(5a-P)和m/z 316.2(3a-1P),或发生脱氧氨基糖苷的开环产生特征离子m/z 116.1(5c-P)。本研究通过总结克拉霉素及其杂质的质谱碎裂规律,为克拉霉素其他杂质及其代谢产物的结构分析提供参考。Clarithromycin has significant antibacterial effect against Gram positive bacteria,and has been widely used as an important clinical antibiotic at present.As a derivative of microbial secondary metabolites,however,clarithromycin products have a large number of impurities,and some trace impurities also need further structural analysis.In this study,the mass spectrometric fragmentation reactions of clarithromycin K and its impurities of KL and KO were systematically studied by electrospray ionization tandem mass spectrometry(ESI-MS/MS)and quantum calculation.Quantum calculation showed that the amino N atom of deoxyaminoglycosides(the No.5 side chain unit)is the most preferred protonation site in the structure of clarithromycin.Upon collisional activation,the protonated molecules undergo a serie of proton migration and fragmentation reactions on side chain groups as the followings:1)The ionizing proton transfers to the O5 a atom in the No.5 side chain group and triggers the loss of macrolides to form an oxonium ion of the dehydrided deoxyaminoglycoside(K5 a-P,m/z 158.1).2)The ionizing proton transfers to the O5 b atom in the No.5 side chain group,which triggers the ring-opeaning reaction of the deoxyaminoglycosides group to give a characteristic fragment ion of N-(3-hydroxybutylidene)-N-methylmethanaminium(K5 c-P,m/z 116.1).3)Migration of the ionizing proton to the O6 atom results in the loss of methanol.4)Migration of the ionizing proton to the O3 a atom results in the formation of K3 a,which undergoes migration of the pyranose unit due to the nucleophilic attack of the O5 d atom of the No.5 side chain unit,and the subsequent loss of macrolides to form an oxonium ion at m/z 316.2(K3 a-1 P).5)K3 a can also undergo nucleophilic reaction due to the nucleophilic attack of the O3 c atom of the para hydroxyl,and subsequent fragmentation to produce the characteristic ion K3 a-2 P by losing C8H12O3,and further cleavage to give the characteristic ion K3 a-2 P-P via the loss of methanol.The impurities of KL and KO have high

关 键 词：克拉霉素 电喷雾串联质谱(ESI-MS/MS) 质谱碎裂反应 量化计算 

分 类 号：O657.63[理学—分析化学]