1
|
Peng L, Ma L, Ran Y, Chen Y, Zeng Z. Metal-free three-component synthesis of thioamides from β-nitrostyrenes, amines and elemental sulfur. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
2
|
Zhang X, Cheng S. Intramolecular Halogen Atom Coordinated H Transfer via Ion-Neutral Complex in the Gas Phase Dissociation of Protonated Dichlorvos Derivatives. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:2246-2254. [PMID: 28681359 DOI: 10.1007/s13361-017-1736-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 05/25/2017] [Accepted: 06/08/2017] [Indexed: 06/07/2023]
Abstract
Intramolecular halogen atom coordinated H transfer reaction in the gas phase dissociation of protonated dichlorvos derivatives has been explored by electrospray ionization tandem mass spectrometry. Upon collisional activation, protonated dichlorvos underwent dissociation reaction via cleavage of the P-O bond to give reactive ion-neutral complex (INC) intermediate, [dimethoxylphosphinoylium + dichloroacetaldehyde]. Besides direct dissociation of the complex, intramolecular chlorine atom coordinated H transfer reaction within the complex takes place, leading to the formation of protonated dimethyl chlorophosphate. To investigate the fragmentation mechanism, deuterium-labeled experiments and several other halogen-substituted (Br and F) analogs of dichlorvos were prepared and evaluated, which display a similar intramolecular halogen transfer. Density functional theory (DFT)-based calculations were performed and the computational results also support the mechanism. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Xiaoping Zhang
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, 330013, People's Republic of China.
| | - Shuai Cheng
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, 330013, People's Republic of China
| |
Collapse
|
3
|
Chai Y, Shao Y, Wang L, Wang L. Loss of benzaldehyde in the fragmentation of protonated benzoylamines: Benzoyl cation as a hydride acceptor in the gas phase. JOURNAL OF MASS SPECTROMETRY : JMS 2017; 52:664-671. [PMID: 28708326 DOI: 10.1002/jms.3969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/04/2017] [Accepted: 07/12/2017] [Indexed: 06/07/2023]
Abstract
In electrospray ionization tandem mass spectrometry of protonated 1-benzoylamines (1-benzoylpiperadine, 1-benzoylmorpholine, and 1-benzoyl-4-methylpiperazine), the dominant fragmentation pathway was amide bond cleavage to form benzoyl cation and neutral amine. Meanwhile, in their fragmentations, an interesting loss of benzaldehyde (106 Da) was observed and identified to derive from hydride transfer reaction between the benzoyl cation and amine. A stepwise mechanism for loss of 106 Da (benzene and CO) could be excluded with the aid of deuterium labeling experiment. Theoretical calculations indicated that hydride transfers from amines (piperadine, morpholine, and 1-methylpiperazine) to benzoyl cation were thermodynamically permitted, and 1-methylpiperazine was the best hydride donor among the 3 amines. The mass spectrometric experimental results were consistent with the computational results. The relative abundance of the iminium cation (relative to the benzoyl cation) in the fragmentation of protonated 1-benzoyl-4-methylpiperazine was higher than that in the fragmentation of the other 2 protonated 1-benzoylamines. By comparing the fragmentations of protonated 1-benzyl-4-methylpiperazine and protonated 1-benzoyl-4-methylpiperazine and the energetics of their hydride transfer reactions, this study revealed that benzoyl cation was a hydride acceptor in the gas phase, but which was weaker than benzyl cation.
Collapse
Affiliation(s)
- Yunfeng Chai
- Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, China
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Yunlong Shao
- Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing, 100124, China
| | - Lu Wang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Lin Wang
- Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing, 100124, China
| |
Collapse
|
4
|
Do JA, Noh E, Yoon SB, Lee JH, Park SK, Mandava S, Baek SY, Lee J. Collision-induced dissociation pathways of H 1-antihistamines by electrospray ionization quadrupole time-of-flight mass spectrometry. Arch Pharm Res 2017; 40:736-745. [PMID: 28601982 DOI: 10.1007/s12272-017-0921-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/14/2017] [Indexed: 11/25/2022]
Abstract
Over the past decades, mass spectrometry technologies have been developed to obtain mass accuracies of one ppm or less. Of the newly developed technologies, quadrupole time-of-flight mass spectrometry (Q-TOF-MS) has emerged as being well suited to routine and high-throughput analyses of pharmaceuticals. Dietary supplements and functional foods have frequently been found to be contaminated with pharmaceuticals. In our continuous efforts to develop methodologies to protect public health against adulterated dietary supplements, we have constructed a mass spectral database for 21 H1-antihistamines encountered as adulterants by using liquid chromatography-electrospray ionization (LC-ESI)/Q-TOF-MS, and have proposed their possible collision-induced dissociation pathways. This database will be very useful for the rapid and accurate detection of H1-antihistamines (known) and their analogues (unknown) illegally added to dietary supplements as well as in other sample matrices.
Collapse
Affiliation(s)
- Jung-Ah Do
- Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju-si, 28159, Republic of Korea
| | - Eunyoung Noh
- Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju-si, 28159, Republic of Korea
| | - Soon-Byung Yoon
- Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju-si, 28159, Republic of Korea
| | - Ji Hyun Lee
- Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju-si, 28159, Republic of Korea
| | - Sung-Kwan Park
- Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju-si, 28159, Republic of Korea
| | - Suresh Mandava
- College of Pharmacy, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Sun Young Baek
- Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju-si, 28159, Republic of Korea.
| | - Jongkook Lee
- College of Pharmacy, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon, Gangwon-do, 24341, Republic of Korea.
| |
Collapse
|