N-[(3S,6S,15S,16R,19S,25R)-25-[[(3S)-1-azabicyclo[2.2.2]octan-3-yl]sulfanylmethyl]-3-[[4-(dimethylamino)phenyl]methyl]-12-ethyl-4,16-dimethyl-2,5,11,14,18,21,24-heptaoxo-19-phenyl-17-oxa-1,4,10,13,20-pentazatricyclo[20.4.0.06,10]hexacosan-15-yl]-3-hydroxypyridine-2-carboxamide
Quinupristin is a semi-synthetic derivative of pristinamycin, a natural occurring type B streptogramin. Quinupristin binds to the bacterial 50S ribosomal subunit, thereby inhibiting peptide chain elongation, and causing early termination of normal bacterial protein synthesis. Quinupristin is primarily effective against gram-positive cocci.