[1] Dalfopristin is synthesized from pristinamycine IIa through achieving a stereoselective Michael-type addition of 2-diethylaminoethanethiol on the conjugated double bond of the dehydroproline ring [4] .
However, using hydrogen peroxide with sodium tungstate in a 2-phase medium produces an improved yield, and is therefore the method of choice for large scale production.
While quinupristin/dalfopristin is effective against staphylococci and vancomycin-resistant Enterococcus faecium, in vitro studies have not demonstrated bactericidal activity against all strains and species of common gram-positive bacteria.
This complex inhibits protein synthesis through prevention of peptide-chain formation and blocking the extrusion of newly formed peptide chains.
[5] Enzymatic drug inactivation may occur in staphylococcal and enterococcal species through production of dalfopristin-inactivating acetyltransferase or quinupristin-inactivating hydrolase.
[citation needed] Both dalfopristin and quinupristin are extensively hepatically metabolized, excreted from the feces, and serve as an inhibitor of cytochrome P450 (CYP) 3A4 enzyme pathway.