7-aminocephalosporanicacid (7-ACA) is convenient starting material for the industrial production of various kinds of semisynthetic cephalosporin antibiotics. In many cases, chemical modifications at the C-7 position is required. Industrially, 7-ACA is derived by chemical or enzymatic deacylation from cephalosporin C, which is fermentatively produced by Acremonium chrysogenum. 7-ACA is a stable only at neutral pHs, enzymatic manipulations are desirable for chemical modifications in the production of cephalosporin related compounds.

Cefetamet pivoxil is an oral third-generation cephalosporin which is hydrolysed to form the active agent, cefetamet. Cefetamet has excellent in vitro activity against the major respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and group A beta-haemolytic streptococci; it is active against beta-lactamase-producing strains of H. influenzae and M. catarrhalis, but has poor activity against penicillin-resistant S. pneumoniae. Cefetamet has marked activity against Neisseria gonorrhoeae and possesses a broad spectrum of activity against Enterobacteriaceae. Both staphylococci and Pseudomonas spp. are resistant to cefetamet. Cefetamet pivoxil has been investigated in the treatment of both upper and lower community-acquired respiratory tract infections and has demonstrated equivalent efficacy to a number of more established agents, namely cefaclor, amoxicillin and cefixime. In complicated urinary tract infections, cefetamet pivoxil showed similar efficacy to cefadroxil, cefaclor and cefuroxime axetil. Cefetamet pivoxil was effective in the treatment of otitis media, pneumonia, pharyngotonsillitis and urinary tract infections in children. Cefetamet is not extensively bound to plasma proteins. Cefetamet has a relatively small apparent volume of distribution consistent with that of other beta-lactam antibiotics. The absorption and disposition of cefetamet in human subpopulations [i.e. children, elderly (< 75 years of age), renal impairment, liver disease and patients taking concomitant drugs] have been studied extensively. Only impaired renal function appears to significantly alter the elimination of this drug. Cefetamet pivoxil exerts its bactericidal action by inhibition the final transpeptidation step of peptidoglycan synthesis in the bacterial cell wall by binding to one or more of the Penicillin-binding Proteins (PBPs).