Screening and identiﬁcation of the main metabolites of 2-amino-9H-pyrido[2,3-b]indole (AαC) in liver microsomes and rat urine by using UPLC-Q-TOF-MS/MS.
2-Amino-9H-pyrido[2,3-b]indole (AαC), which has been reported to be 40-258ng per cigarette, was regarded as a probable human carcinogen (Group 2B) and harmful composition in Hoffman list. Thus, it is of great significance to develop an effective method for the accurate identification of AαC and its metabolites. In the present study, we have investigated for the first time the in vivo and in vitro metabolites of AαC using ultra performance liquid chromatography combined with diode array detector and time-of-flight mass spectrometry (UPLC-DAD and UPLC-Q-TOF-MS/MS). A comparative study showed that the metabolic patterns of AαC in beagle, mouse, rat and human liver microsomes were of significant difference with these in rat urine. For the metabolism of AαC in liver microsomes, nine metabolites of AαC, including five hydroxy metabolites, two quinone metabolites and two N-dimer metabolites, have been found. However, metabolism of AαC in rats is a phase II process with complex enzyme catalysis, 23 metabolites including C- and N-oxidation, O- and N-glycosylation, O- and N-sulfonation, and N-acetylation were identified in rat urine. In addition, five new N-acetyl-AαC-OH metabolites were identified for the first time, indicating a possible new pathway for the metabolism. This study significantly enriched our knowledge about the metabolism of AαC, and will be useful for a better understanding of its harmfulness and toxicity.
Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China; School of Material Science and Engineering, Zhengzhou University, Zhengzhou 450001, China.
Kai
K
Hu
Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.
Ge
G
Zhao
Technology Center of Henan Tobacco Industrial Co., Ltd., Zhengzhou, China.
Yufeng
Y
Fu
Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.
Sheng
S
Wang
College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China.
Hang
H
Yuan
Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.
Fuwei
F
Xie
College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China.
Shusheng
S
Zhang
Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.
Huimin
H
Liu
School of Material Science and Engineering, Zhengzhou University, Zhengzhou 450001, China.
Minying
M
Liu
D000818:Animals; D002243:Carbolines / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D008297:Male; D053858:Metabolic Networks and Pathways; D008862:Microsomes, Liver / Q000378:metabolism*; D051381:Rats; D053719:Tandem Mass Spectrometry / Q000379:methods*
D002243:Carbolines; C017822:2-amino-9H-pyrido(2,3-b)indole
2-Amino-9H-pyrido[2,3-b]indole; Liver microsomes; Metabolites; Rat urine; ：UPLC-Q-TOF-MS/MS