Cefoxitin is a cephamycin antibiotic often grouped with the second-generation cephalosporins. It is active against a broad range of gram-negative bacteria including anaerobes. The methoxy group in the 7a position provides cefoxitin with a high degree of stability in the presence of beta-lactamases, both penicillinases and cephalosporinases, of gram-negative bacteria. The bactericidal action of cefoxitin results from inhibition of cell wall synthesis.

Cefazolin is a semisynthetic cephalosporin analog with broad-spectrum antibiotic action due to inhibition of bacterial cell wall synthesis. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, cefazolin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins. Cefazolin is used to treat bacterial infections of the skin, moderately severe bacterial infections involving the lung, bone, joint, stomach, blood, and urinary tract. It is clinically effective against infections caused by staphylococci and streptococci species of Gram positive bacteria. This drug also can be used for perioperative prophylaxis.

Rofleponide is a third generation synthetic glucocorticosteroid. This compound has high affinity for the rat thymus glucocorticoid receptor and showed a very high biotransformation rate in the human liver. Rofleponide was being investigated for its anti-inflammatory, immunosuppressive and anti-anaphylactic activity. It was evaluated in phase II clinical trials for its safety and efficacy in allergic rhinitis and asthma, and in a preclinical study for use in inflammatory bowel disease, but development of this drug was discontinued. Rofleponide was never marketed.

Ceftiolene (42980RP) is a new cephalosporin with a broad antibacterial spectrum similar to cefotaxime or ceftriaxone. The affinities of ceftiolene for penicillin-binding proteins are very comparable with those of ceftriaxone and cefotaxime for Escherichia coli, and generally greater than those of latamoxef (moxalactam) for the higher molecular weight PBPs of E. coli. Enterobacter cloacae. The affinity of ceftiolene for PBP1 of Staphylococcus aureus is greater than those of cefotaxime or latamoxef but comparable with these antibiotics for PBP3. The bacteriolytic activity of ceftiolene at defined concentrations against Gram-negative organisms is similar to that of ceftriaxone and significantly better than that of the other third-generation cephalosporins tested.

Penicillic acid (PA) is a polyketide mycotoxin produced by several species of Aspergillus and Penicillium species showed antibacterial activity against various plant pathogenic bacteria and can be as a lead molecule for the development of synthetic agrochemicals to control plant bacterial diseases. In addition, PA induces single-strand DNA breaks and inhibits DNA synthesis, demonstrating mutagenic and cytotoxic effects. Penicillic acid irreversibly inhibits GDP-mannose dehydrogenase (DMG), an alginate synthesis enzyme, interrupting the committed step in alginate biosynthesis.

Gemifloxacin is an oral broad-spectrum quinolone antibacterial agent used in the treatment of acute bacterial exacerbation of chronic bronchitis and mild-to-moderate pneumonia. Gemifloxacin mesylate is marketed under the brand name Factive, indicated for the treatment of bacterial infection caused by susceptible strains such as S. pneumoniae, H. influenzae, H. parainfluenzae, or M. catarrhalis, S. pneumoniae (including multi-drug resistant strains [MDRSP]), M. pneumoniae, C. pneumoniae, or K. pneumoniae. Gemifloxacin has in vitro activity against a wide range of Gram-negative and Grampositive microorganisms. Gemifloxacin is bactericidal with minimum bactericidal concentrations (MBCs) generally within one dilution of the minimum inhibitory concentrations (MICs). Gemifloxacin acts by inhibiting DNA synthesis through the inhibition of both DNA gyrase and topoisomerase IV (TOPO IV), which are essential for bacterial growth. Streptococcus pneumoniae showing mutations in both DNA gyrase and TOPO IV (double mutants) are resistant to most fluoroquinolones. Gemifloxacin has the ability to inhibit both enzyme systems at therapeutically relevant drug levels in S. pneumoniae (dual targeting), and has MIC values that are still in the susceptible range for some of these double mutants.

Sparfloxacin is a synthetic fluoroquinolone broad-spectrum antimicrobial agent in the same class as ofloxacin and norfloxacin. Sparfloxacin has in vitro activity against a wide range of gram-negative and gram-positive microorganisms. Sparfloxacin exerts its antibacterial activity by inhibiting DNA gyrase, a bacterial topoisomerase. DNA gyrase is an essential enzyme which controls DNA topology and assists in DNA replication, repair, deactivation, and transcription. Quinolones differ in chemical structure and mode of action from (beta)-lactam antibiotics. Quinolones may, therefore, be active against bacteria resistant to (beta)-lactam antibiotics. Although cross-resistance has been observed between sparfloxacin and other fluoroquinolones, some microorganisms resistant to other fluoroquinolones may be susceptible to sparfloxacin. In vitro tests show that the combination of sparfloxacin and rifampin is antagonistic against Staphylococcus aureus. The bactericidal action of sparfloxacin results from inhibition of the enzymes topoisomerase II (DNA gyrase) and topoisomerase IV, which are required for bacterial DNA replication, transcription, repair, and recombination. Sparfloxacin is used for the treatment of adults with the following infections caused by susceptible strains microorganisms: community-acquired pneumonia (caused by Chlamydia pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, or Streptococcus pneumoniae) and acute bacterial exacerbations of chronic bronchitis (caused by Chlamydia pneumoniae, Enterobacter cloacae, Haemophilus influenzae, Haemophilus parainfluenzae, Klebsiella pneumoniae, Moraxella catarrhalis,Staphylococcus aureus, or Streptococcus pneumoniae). Sparfloxacin has trade names Spacin in Bangladesh, Zagam and Zagam Respipac. Zagam is no longer available in the United States.

Enoxacin is an oral broad-spectrum fluoroquinolone antibacterial agent used in the treatment of urinary tract infections and gonorrhea. Enoxacin is bactericidal drugs, eradicating bacteria by interfering with DNA replication. Like other fluoroquinolones, enoxacin functions by inhibiting bacterial DNA gyrase and topoisomerase IV. The inhibition of these enzymes prevents bacterial DNA replication, transcription, repair and recombination. Enoxacin is active against many Gram-positive bacteria. After oral administration enoxacin is rapidly and well absorbed from the gastrointestinal tract. The antibiotic is widely distributed throughout the body and in the different biological tissues. Tissue concentrations often exceed serum concentrations. The binding of enoxacin to serum proteins is 35 to 40%. The serum elimination half-life, in subjects with normal renal function, is approximately 6 hours. Approximately 60% of an orally administered dose is excreted in the urine as unchanged drug within 24 hours. Enoxacin, like other fluoroquinolones, is known to trigger seizures or lower the seizure threshold. The compound should not be administered to patients with epilepsy or a personal history of previous convulsive attacks as may promote the onset of these disorders.

Loracarbef (KT3777) is carbacephem antibiotic structurally identical to cefaclor, except that the sulfur atom of position 1 of the cephem nucleus has been replaced by carbon. It showed good affinity for penicillin-binding proteins. At low concentrations (< 2 mg/L) in vitro, it inhibits Streptococcus pneumoniae, S. pyogenes, beta-haemolytic streptococci groups B, C and G. Proteus mirabilis and Moraxella catarrhalis, including beta-lactamase-producing strains. At therapeutic plasma concentrations it is also active in vitro against most strains of Staphylococcus aureus, S. saprophyticus, Escherichia coli and beta-lactamase-positive and -negative strains of Haemophilus influenzae. Loracarbef has been indicated in the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms.