This invention provides novel β-lactamase inhibitors of the
aryl- and heteroarylsulfonamidomethylphosphonate monoester class having
nitrogen-based cations or quarternary
ammonium groups. The compounds inhibit three classes of β-
lactamases and synergize the antibacterial effects of β-
lactam antibiotics (e.g.,
imipenem and
ceftazidime) against those micro-organisms normally resistant to the β-
lactam antibiotics as a result of the presence of the β-
lactamases. Formula (I) or pharmaceutically acceptable salt thereof.