Monobactams
Aztreonam is the archetypal monobactam. Other monobactams include tigemonam, nocardicin A, carumonam and tabtoxin. An example of a monobactam that lacks antibiotic activity, but is used clinically for other purposes, is the cholesterol absorption inhibitor ezetimibe which is used to treat hypercholesterolemia.
The antibacterial activity of the clinically established monobactam ATM is mediated mainly by inhibition of penicillin binding protein 3 (PBP3), interfering with peptidoglycan synthesis and cell division (septation)
Aztreonam may be administered intramuscularly or intravenously; absorption after oral administration is poor. The primary route of elimination is the urine.
Monobactams are a class of beta-lactam antibiotics with a broad spectrum of antibacterial activity, and have a structure which renders them highly resistant to beta-lactamases. Unlike penams and cephems, monobactams do not have any ring fused to its four-member lactam structure.
The monobactams are antibiotics possessing only the β-lactam moiety, are active against Gram-negative bacteria and are considered inactive against Gram-positive bacteria.
Monobactams have a sulfonate group instead of a carboxylate group that is directly attached to the nitrogen atom of the β-lactam ring without an additional ring structure. Various additional moieties are attached to both sides of the core ring structures.
Monobactams can inhibit the transformation of peptidoglycan-synthesis process of bacteria, resulting in bacteria loses the ability of resistance to osmotic pressure and burst. Peptidoglycan is essential, especially for gram-positive bacteria cell wall structural integrity.





