Piroxicillin is a broad-spectrum antibiotic. In vitro it is more active than piperacillin, apalcillin and mezlocillin especially against the following strains; E. coli, Ps. aeruginosa, Ps. stutzeri, K. pneumoniae, Eb. cloacae, Ser. marcescens, Proteus, Sh. flexneri, Y. enterocolitica, Cb. freundii, Acb. calcoaceticus, Bacteroides and Sc. faecalis. It shows very low MIC values against clinically important Gram-negative bacteria, primarily Pseudomonas aeruginosa. The action of piroxicillin is bactericidal.

Adicillin (Penicillin N) is a penicillin derivative produced by Cephalosporium acremonium. Adicillin is dextrorotatory. Inactivated by penicillinase as is penicillin G, but differs from the common penicillin by its antibacterial activity and hydrophilic character. Active against Sarcina lutea, Proteus vulgaris, Salmonella typhimurium, Diplococcus pneumoniae. Shows practically no activity against B. subtilis and Staph. aureus. The toxicity is somewhat less than that of penicillin G, although penicillin N is excreted more slowly.

Trospectomycin is an aminocyclitol antibiotic similar in structure to spectinomycin. The drug was originally developed by Pharmacia & Upjohn. It is a 6'-propyl analogue of spectinomycin, and lacks the aminosugars in glycosidic linkage which are thought to be responsible for the ototoxicity and nephrotoxicity associated with the aminoglycosides. The mechanism of action of trospectomycin is similar to that of its parent compound, spectinomycin: it binds to the bacterial 30S ribosome and inhibits protein synthesis. The transport mechanism for its delivery to its target site does not appear to be oxygen dependent, and this explains the in-vitro activity of trospectomycin against anaerobic organisms. Trospectomycin has activity against a broad spectrum of pathogenic organisms including Streptococcus, Haemophilus, Gardnerella, Neisseria, Peptococcus, Peptostreptococcus, Bacteroides, Mobiluncus, Chlamydia, Mycoplasma and Ureaplasma spp. Results of in-vivo testing suggest potential utility in a variety of clinical conditions including non-gonococcal urethritis, chlamydial cervicitis, gonorrhoea, pelvic inflammatory disease, pneumonia, anaerobic infections and meningitis. Trospectomycin progressed to late stage clinical trials for treatment of pelvic inflammatory disease (chlamydia) before being abandoned for commercial reasons as the third generation cephalosporins and second generation macrolides in development and use were judged superior at the time.

Cefedrolor is a broad-spectrum cephalexin antibiotic patented by pharmaceutical company Bristol-Myers Co.

Amicycline is an anti-bacterial agent, an antibiotic of tetracycline class.

Premafloxacin is an 8-methoxy fluoroquinolone derivative patented by American pharmaceutical company Warner-Lambert Co. as an antibacterial agent. In preclinical studied. Premafloxacin was equivalent to ciprofloxacin, enrofloxacin, and danofloxacin in activity against the gram-negative bacilli but was much more active than the comparison antimicrobial agents (against the staphylococci, streptococci, and anaerobes. Premafloxacin acts as a topoisomerase IV inhibitor with enhanced activity against Staphylococcus aureus.

Lexithromycin is an early semi-synthetic erythromycin, prepared by reaction of the 9-keto moiety to methyl oxime. Lexithromycin has improved absorption in vivo over erythromycin due to increased hydrophopicity and pH stability. Like all erythromycins, lexithromycin shows broad spectrum antibacterial activity and acts by binding to the 30S and 50S ribosomal sub-units, blocking protein synthesis. Formulations containing lexithromycin were tested in clinical trials as treatment for HIV but were discontinued.

Suncillin is an antibacteria and antifungal agent produced in Phytera's laboratory from a cell culture of a plant. Suncillin was patented by Bristol-Myers Co. In 1968 for the Pseudomonas bacteria treatment but was never marketed.

There is a little information around sancycline. It is known, that it was synthesized by Conover and co-workers in 1962 and it was antibacterial compound. It was proposed that sancycline binds to the 30S of bacterial ribosomal subunit and inhibiting protein translation by blocking entry of aminoacyl-tRNA into the ribosome A site.