Discovery of Brominated Alboflavusins With Anti-MRSA Activities

Halogenated Antimicrobial Agents to Combat Drug-Resistant Pathogens

Antimicrobial resistance presents us with a potential global crisis as it undermines the abilities of conventional antibiotics to combat pathogenic microbes. The history of antimicrobial agents is replete with examples of scaffolds containing halogens. In this review, we discuss the impacts of halogen atoms in various antibiotic types and antimicrobial scaffolds and their modes of action, structure-activity relationships, and the contributions of halogen atoms in antimicrobial activity and drug resistance. Other halogenated molecules, including carbohydrates, peptides, lipids, and polymeric complexes, are also reviewed, and the effects of halogenated scaffolds on pharmacokinetics, pharmacodynamics, and factors affecting antimicrobial and antivirulence activities are presented. Furthermore, the potential of halogenation to circumvent antimicrobial resistance and rejuvenate impotent antibiotics is addressed. This review provides an overview of the significance of halogenation, the abilities of halogens to interact in biomolecular settings and enhance pharmacological properties, and their potential therapeutic usages in preventing a postantibiotic era. SIGNIFICANCE STATEMENT: Antimicrobial resistance and the increasing impotence of antibiotics are critical threats to global health. The roles and importance of halogen atoms in antimicrobial drug scaffolds have been established, but comparatively little is known of their pharmacological impacts on drug resistance and antivirulence activities. This review is the first to extensively evaluate the roles of halogen atoms in various antibiotic classes and pharmacological scaffolds and to provide an overview of their ability to overcome antimicrobial resistance.

Halogenated Pyrrolopyrimidines with Low MIC on Staphylococcus aureus and Synergistic Effects with an Antimicrobial Peptide

Currently, there is a world-wide rise in antibiotic resistance causing burdens to individuals and public healthcare systems. At the same time drug development is lagging behind. Therefore, finding new ways of treating bacterial infections either by identifying new agents or combinations of drugs is of utmost importance. Additionally, if combination therapy is based on agents with different modes of action, resistance is less likely to develop. The synthesis of 21 fused pyrimidines and a structure-activity relationship study identified two 6-aryl-7H-pyrrolo [2,3-d] pyrimidin-4-amines with potent activity towards Staphylococcus aureus. The MIC-value was found to be highly dependent on a bromo or iodo substitution in the 4-benzylamine group and a hydroxyl in the meta or para position of the 6-aryl unit. The most active bromo and iodo derivatives had MIC of 8 mg/L. Interestingly, the most potent compounds experienced a four-fold lower MIC-value when they were combined with the antimicrobial peptide betatide giving MIC of 1–2 mg/L. The front runner bromo derivative also has a low activity towards 50 human kinases, including thymidylate monophosphate kinase, a putative antibacterial target.