Synthesis of a Conformationally Fixed Bicyclomarin Derivative
Jennifer Greve1, Alexander F Kiefer2, Uli Kazmaier1
1Organic Chemistry, Saarland University, Campus C4.2, 66123, Saarbrücken, Germany.
Chemmedchem
|September 3, 2025
Summary
Researchers synthesized a new bicyclic cyclomarin derivative to improve tuberculosis treatment. While the synthesis was successful, the modified compound exhibited lower activity than the original cyclomarin.
Area of Science:
- Medicinal Chemistry
- Organic Synthesis
- Antimicrobial Drug Discovery
Background:
- Cyclomarin is a potential therapeutic agent against tuberculosis.
- Understanding the structure-activity relationship of cyclomarin is crucial for developing improved analogs.
- The ClpC1 enzyme is a validated target for antitubercular drugs.
Purpose of the Study:
- To synthesize a conformationally fixed, bicyclic cyclomarin derivative.
- To evaluate the antitubercular activity of the novel bicyclic compound.
- To explore the impact of conformational restriction on cyclomarin's efficacy.
Main Methods:
- X-ray crystallography was used to determine the structure of cyclomarin bound to ClpC1.
- Multi-step organic synthesis was employed to construct the bicyclic cyclomarin derivative.
- Antitubercular activity assays were performed to compare the efficacy of the new compound with cyclomarin.
Main Results:
- A novel bicyclic cyclomarin derivative was successfully synthesized.
- The synthesis involved straightforward formation of a linear heptapeptide and two macrolactamizations.
- A low yield was observed in the final benzyl ether cleavage step.
- The resulting bicyclic compound demonstrated reduced antitubercular activity compared to the parent cyclomarin.
Conclusions:
- Conformational restriction of cyclomarin did not enhance its antitubercular activity.
- The synthetic route, while largely successful, presents challenges in the final deprotection step.
- Further structural modifications may be necessary to improve the efficacy of cyclomarin derivatives against tuberculosis.
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