Discovered as natural products from actinomycetes soil bacteria, the tetracyclines were first reported in the scientific literature in 1948. They were noted for their broad spectrum antibacterial activity and were commercialized with clinical success beginning in the late 1940s to the early 1950s. By catalytic hydrogenation of Aureomycin, using palladium metal and hydrogen, the C7 deschloro derivative was synthesized, producing a compound of higher potency, a better solubility profile, and favorable pharmacological activity; it was subsequently named tetracycline. Tetracyclines are primarily bacteriostatic and exert their antimicrobial effect by the inhibition of protein synthesis by binding to the 30S ribosomal subunit. Tetracycline is active against a broad range of gram-negative and gram-positive organisms. Tetracycline is indicated in the treatment of infections caused by susceptible strains. To reduce the development of drug-resistant bacteria and maintain the effectiveness of tetracycline hydrochloride and other antibacterial drugs, tetracycline hydrochloride should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.

Novobiocin (also known as streptonivicin) is an aminocoumarin antibiotic, active against Staphylococcus epidermidis. Novobiocin and other aminocoumarin antibiotics act as a potent competitive inhibitor of DNA gyrase B. The oral form of the drug was withdrawn from the market in 1999 due to safety or effectiveness reasons. Later it was discovered that novobiocin inhibited Hsp90 and topoisomerase II, and novobiocin was investigated in clinical trials against metastatic breast cancer and non-small cell lung cancer. Topical form of novobiocin was investigated in combination with nalidixic acid for treatment of psoriasis.