Dalfopristin (mesylate), 1 MG

Dalfopristin is a semi-synthetic analogue of ostreogrycin A (virginiamycin M, pristinamycin IIA, streptogramin A) formed by addition of diethylaminoethylthiol to the 2-pyrroline group of ostreogrycin, followed by oxidation to the sulfone. The structural changes provide a more hydrophobic compound with a readily ionisable group for generating a salt.

Dalfopristin is used commercially in synergistic combination with quinupristin (70:30). There is little published data on the synthesis, biological or antibiotic activity of dalfopristin alone, however the combination product is highly effective, including activity against antibiotic resistant strains.