<unk>  is a carboxypenicillin.  It is almost invariably sold and used in combination with clavulanate as Timentin®.  Because it is a penicillin, it also falls within the larger class of beta-lactam antibiotics. Its main clinical use is as an injectable antibiotic for the treatment of gram negative bacteria, in particular, Pseudomonas aeruginosa.
Chemically,<unk>  is C15H16N2O6S2 (CAS number 34787-01-4). It is provided as a white or pale yellow powder. It is highly soluble in water, but should only be dissolved immediately before use to prevent degradation.
Ticarcillin
Plicamycin
Sultamicillin
Vancomycin 
Piperacillin
Meropenem
Piperacillin sodium
Colistin