Computational analysis of the interactions of a novel cephalosporin derivative with β-lactamases

Design, Synthesis, and Evaluation of Cephamycin-Based Antisporulation Agents targeting Clostridioides difficile

With the aim of discovering small molecule inhibitors of the sporulation process in Clostridioides difficile, we prepared a series of C-7 α-(4-substituted-1H-1,2,3-triazol-1-yl)acetamide analogues of cefotetan, a known inhibitor of the C. difficile sporulation-specific protein target CdSpoVD. These analogues were evaluated using both in vitro binding assays with CdSpoVD and antisporulation assays against C. difficile. Further design concepts were aided utilizing the predicted docking scores (DS) using both AlphaFold (AF) models, and a crystal structure of the CdSpoVD protein (PDB 7RCZ). Despite being 1 order of magnitude more potent as a sporulation inhibitor than cefotetan, in vivo studies on compound 6a in a murine-model of C. difficile infection demonstrated comparable spore shedding capabilities as cefotetan. Importantly, compound 6a had no concerning broad spectrum antibacterial activities, toxicity, or hemolytic activity and thus has potential for further drug development.

The Odd Couple(s): An Overview of Beta-Lactam Antibiotics Bearing More Than One Pharmacophoric Group

β-lactam antibiotics are among the most important and widely used antimicrobials worldwide and are comprised of a large family of compounds, obtained by chemical modifications of the common scaffolds. Usually these modifications include the addition of active groups, but less frequently, molecules were synthesized in which either two β-lactam rings were joined to create a single bifunctional compound, or the azetidinone ring was joined to another antibiotic scaffold or another molecule with a different activity, in order to create a molecule bearing two different pharmacophoric functions. In this review, we report some examples of these derivatives, highlighting their biological properties and discussing how this strategy can lead to the development of innovative antibiotics that can represent either novel weapons against the rampant increase of antimicrobial resistance, or molecules with a broader spectrum of action.

New compounds for a good old class: Synthesis of two Β-lactam bearing cephalosporins and their evaluation with a multidisciplinary approach

Antimicrobial resistance is spreading massively in the world and is becoming one of the main health threats of the 21st century. One of the possible strategies to overcome this problem is to modify the known classes of antibiotics in a rational way, with the aim of tuning their efficacy. In this paper, we present the synthesis and the evaluation of the biological activity of a series of two β-lactam bearing cephalosporin derivatives, in which an additional isolated azetidinone ring, bearing different substituents, is joined to the classical cephalosporanic nucleus by a chain of variable length. A computational approach has been also applied in order to predict the molecular interactions between some representative derivatives and selected penicillin-binding proteins, the natural targets of β-lactam antibiotics. All these derivatives are active against Gram-positive bacteria, with MIC₁₀₀ comparable or even better than that of the reference antibiotic ceftriaxone, and show no or very low cytotoxic activity on different cell lines. Overall, these molecules appear to be able to exert their activity in particular against microorganisms belonging to some of the species more involved in the development of multidrug resistance.