(6R,7R,10R,11R,12E,17E,19E,21S)-6-[2-(diethylamino)ethylsulfonyl]-21-hydroxy-11,19-dimethyl-10-propan-2-yl-9,26-dioxa-3,15,28-triazatricyclo[23.2.1.03,7]octacosa-1(27),12,17,19,25(28)-pentaene-2,8,14,23-tetrone
Dalfopristin is a semi-synthetic derivative of streptogramin A produced by streptomycetes. Dalfopristin inhibits the early phase of protein synthesis in the bacterial ribosome by binding to the 70S subunit, and also alters the configuration of the ribosome to make it more susceptible for streptogramin B binding. Dalfopristin is used in combination with quinopristin, a streptogramin B derivative. This combination is active against most gram-positive organisms, including Enterococcus faecium, and is also active against some gram-negative organisms and mycoplasma.