Identification by LC/MS(n) of degradates of a novel carbapenem antibiotic in an aqueous matrix
Increased drug resistance in Staphylcocci and Enterococci to currently available antibiotics has significantly limited therapeutic options. Recently, a novel carbapenem antibiotic (Compound A) with a releasable side chain adjacent to the carbapenem was investigated to combat methicillin- and vancomy...
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Published in | Journal of pharmaceutical and biomedical analysis Vol. 29; no. 1-2; pp. 173 - 181 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
England
20.06.2002
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Subjects | |
Online Access | Get full text |
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Summary: | Increased drug resistance in Staphylcocci and Enterococci to currently available antibiotics has significantly limited therapeutic options. Recently, a novel carbapenem antibiotic (Compound A) with a releasable side chain adjacent to the carbapenem was investigated to combat methicillin- and vancomycin-resistant Staphylococci and vancomycin-resistant Enterococci. The major advantage of Compound A over existing antibiotics can be attributed to the fact that cleavage of the side chain upon beta-lactam ring opening retained anti-bacterial activity while expelling the immunodominant epitope of the presumed beta-lactam hapten. In this work, LC/MS methods were developed to identify degradates of Compound A in an aqueous matrix utilized in assessing product safety and supporting analytical method and formulation development. A total of eight significant degradates were observed in this Compound A sample by LC/MS(n) and other techniques. Detailed structural analysis of degradates based upon LC/MS(n) data and other supporting results will be described in this work. Proposed molecular structures were confirmed by synthesis and use of authentic standards for several degradates. Degradates 1 and 4 were identified as degradates formed through the reversal of Michael reaction from Degradate 3 that is apparently formed by hydrolysis. Degradates 2 and 8 were found to be Hofmann elimination degradates. Degradates 5 and 6 are believed to be formed through dimerization of two parent molecules followed by the reversal of Michael reaction. Finally, Degradate 7 is attributed to a displacement reaction. Potential degradation pathways based upon these preliminary studies will also be discussed. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0731-7085 |
DOI: | 10.1016/S0731-7085(02)00008-0 |