| abstract |
Provided by the present invention are cephem derivatives represented by general formulae (IA) or (IB) or (IC) wherein Ar is an optionally substituted lipophilic phenyl, naphthyl or pyridyl group; L1 and L2 are (C1-C6)alkyl optionally substituted with hydroxy or keto and/or optionally interrupted with a vinyl group, S, O, aryl, heteroaryl, (a) or (b); in which R1 is H or (C1-C6)alkyl; A is CO2H, PO3H, SO3H, tetrazole, squaric acid or a hydroxyl group; and Q is a quaternized nitrogen group. The derivatives are gram-positive antibacterial agents especially useful in the treatment of diseases caused by methicillin-resistant Staphylococcus aureus. |