Drug Repurposing by Siderophore Conjugation: Synthesis and Biological Evaluation of Siderophore-Methotrexate Conjugates as Antibiotics.

Drug repurposing is considered a promising strategy to fight antimicrobial resistance (AMR). Methotrexate (Mtx), a classical anticancer drug, could strongly inhibit bacterial dihydrofolate reductase (DHFR). However, its poor permeability into bacteria and potent human cytotoxicity make it unsuitable as an antibacterial.

Synthesis of Vitamin B-Antibiotic Conjugates with Greatly Improved Activity against Gram-Negative Bacteria.

There is an urgent need to discover new antibiotics and improve the efficacy of known antibiotics against Gram-negative bacteria. "Trojan horse" conjugates are novel and promising antibiotics. Herein we report the design and synthesis of vitamin-B-ampicillin conjugates, which exhibited more than 500 times improved activity against compared with ampicillin itself.

Iridium-Catalyzed Cycloisomerization of -Tethered 1,7-Enynes: Construction of an Azabicyclo[5.1.0]octene System.

An efficient method for the synthesis of azabicyclo[5.1.0]octenes through cycloisomerization of nitrogen-tethered 1,7-enynes catalyzed by [IrCp*Cl] was developed.