Selectively guanidinylated aminoglycosides as antibiotics.
The emergence of virulent, drug-resistant bacterial strains coupled with a minimal output of new pharmaceutical agents to combat them makes this a critical time for antibacterial research. Aminoglycosides are a well-studied, highly potent class of naturally occurring antibiotics with scaffolds amenable to modification, and therefore, they provide an excellent starting point for the development of semisynthetic, next-generation compounds. To explore the potential of this approach, we synthesized a small library of aminoglycoside derivatives selectively and minimally modified at one or two positions with a guanidine group replacing the corresponding amine or hydroxy functionality. Most guanidino-aminoglycosides showed increased affinity for the ribosomal decoding rRNA site, the cognate biological target of the natural products, when compared with their parent antibiotics, as measured by an in vitro fluorescence resonance energy transfer (FRET) A-site binding assay. Additionally, certain analogues showed improved minimum inhibitory concentration (MIC) values against resistant bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA). An amikacin derivative holds particular promise with activity greater than or equal to the parent antibiotic in the majority of bacterial strains tested.
Department of Chemistry & Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
Richard J
RJ
Fair
Mary E
ME
Hensler
Wdee
W
Thienphrapa
Quang N
QN
Dam
Victor
V
Nizet
Yitzhak
Y
Tor
D000617:Aminoglycosides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D015195:Drug Design; D006146:Guanidines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008968:Molecular Conformation; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D006146:Guanidines