Natural and semi-synthetic antibiotics

Rifaximin: an oral semi-synthetic antibiotic from rifamycin SV; targets bacterial RNA polymerase to halt growth.

N-[(2E)-6,6-Dimethyl-2-hepten-4-ynyl]-1-naphthalenemethanamine (DHEA) is a human metabolite and an endogenous hormone. DHEA has been shown to have antifungal activity against Candida albicans in vitro. It also possesses an inhibitory effect on the growth of some fungi that are resistant to azole drugs, such as Coccidioides immitis, Cryptococcus neoformans and Blastomyces dermatitidis. DHEA has been used in the treatment of pediatric patients with chronic granulomatous disease and is currently being evaluated for use in other pediatric conditions.

(trans)-4-Propyl-1-methyl-L-proline is a synthetic compound that has been used in the past as an impurity standard in the synthesis of several drugs, including metaxalone and aminopyrine. It is also found to have pharmacological effects on its own and was used as a drug product for the treatment of rheumatoid arthritis. (trans)-4-Propyl-1-methyl-L-proline is not listed in any pharmacopoeia or international list of approved drugs.

Lincomycin B is a chemical compound that belongs to the group of antimicrobial agents. It is used in the treatment of viral infections and has been shown to have an effect against HIV-1, herpes simplex virus, and influenza A virus. Lincomycin B inhibits protein synthesis by binding to the ribosomes in bacteria and inhibiting peptide elongation. The optimum concentration for this compound is 0.2 mM with a minimum inhibitory concentration of 1 mM. Lincomycin B can be synthesized by reacting sodium hydroxide solution with hydrochloric acid or hydroxide solution at a temperature range from 30 °C to 70 °C.