UCP1173, propargyl-linked antifolate, is an antibacterial agent. UCP1173 inhibits DHFR enzymes, with IC50 values of 0.014 µM for DfrB, 0.19 µM for DfrG, 0.27 µM for DfrA, and 0.091 µM for DfrK. UCP1173 inhibits growth of Staphylococcus aureus clinical isolates carrying dfrA, dfrG, or dfrK resistance genes. UCP1173 can be used for the research of bacterial infections[1].