Electrospray ionization tandem mass spectrometric studies to probe the interaction of Cu(II) with amoxicillin

• Published in: Chinese chemical letters Vol. 25; no. 1; pp. 39 - 45
• Main Authors: Sekar, Ramaiyan, Kailasa, Suresh Kumar, Chen, Yuan-Chin, Wu, Hui-Fen
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2014
• Subjects: Amoxicillin; Copper ion; ESI-MS; ESI-MS; Copper ion; Amoxicillin
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2013.10.012

This study describes the application of electrospray ionization mass spectrometry (ESI-MS) to the investigation of copper ion interaction with amoxicillin. ESI mass spectra of Cu–amoxicillin complexes show complex ions at m/z 828, 792, 753, 731, 428, 388 and 366 corresponding to [63Cu+(2A-H)+2H2O]+, [63Cu+(2A-H)]+, [2A+Na]+, [2A+H]+, [63Cu+(A-H)]+, [A+Na]+ and [A+H]+ (where A=amoxicillin), respectively. This study describes the application of electrospray ionization mass spectrometry (ESI-MS) to investigate copper ion interaction with amoxicillin. ESI mass spectra of Cu–amoxicillin complexes show complex ions at m/z 828, 792, 753, 731, 428, 388 and 366 corresponding to [63Cu+(2A-H)+2H2O]+, [63Cu+(2A-H)]+, [2A+Na]+, [2A+H]+, [63Cu+(A-H)]+, [A+Na]+ and [A+H]+ (where A=amoxicillin). Based on the observed m/z values of Cu–amoxicillin complex ions, it is found that the Cu–amoxicillin ratios are 1:1 and 1:2, and the copper ions exhibited three feasible coordination numbers (2, 4 and 6) with amoxicillin complexes. The structures and coordination numbers of copper–amoxicillin complex ions were probed from their collisionally activated dissociation (CAD) spectra. Based on these results, it is confirmed that the copper ions could form stable tetrahedral and octahedral complexes with amoxicillin. This study validates the applicability of ESI-MS for probing copper–amoxicillin complex ions.