Amphenicols are a class of

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

with a

phenylpropanoid The phenylpropanoids are a diverse family of organic compounds that are biosynthesized by plants from the amino acids phenylalanine and tyrosine in the shikimic acid pathway. Their name is derived from the six-carbon, aromatic phenyl group and ...

structure. They function by blocking the enzyme

peptidyl transferase The peptidyl transferase center (, PTC) is an Aminoacyltransferases, aminoacyltransferase ribozyme (RNA enzyme) located in the large subunit of the ribosome. It forms peptide bonds between adjacent amino acids during the Translation (genetics), ...

on the

50S 50 S is the larger subunit of the 70S ribosome of prokaryotes, i.e. bacteria and archaea. It is the site of inhibition for antibiotics such as macrolides, chloramphenicol, clindamycin, and the pleuromutilins. It includes the 5S ribosom ...

ribosome Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order s ...

subunit of

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

. Examples of amphenicols include

chloramphenicol Chloramphenicol is an antibiotic useful for the treatment of a number of bacterial infections. This includes use as an eye ointment to treat conjunctivitis. By mouth or by intravenous, injection into a vein, it is used to treat meningitis, pl ...

thiamphenicol Thiamphenicol (also known as thiophenicol and dextrosulphenidol) is an antibiotic. It is the methyl-sulfonyl analogue of chloramphenicol and has a similar spectrum of activity, but is 2.5 to 5 times as potent. Like chloramphenicol, it is insolub ...

, azidamfenicol, and

florfenicol Florfenicol (marketed by Schering-Plough Animal Health under the brand name Nuflor) is a fluorinated synthetic analog of thiamphenicol, mainly used as a antibiotic in veterinary medicine. Florfenicol is available a generic medication. Veter ...

. The first-in-class compound was chloramphenicol, introduced in 1949. Chloramphenicol was initially discovered as a natural product and isolated from the soil bacteria ''

Streptomyces venezuelae ''Streptomyces venezuelae'' is a species of soil-dwelling Gram-positive bacterium of the genus ''Streptomyces''. ''S. venezuelae'' is filamentous. In its spore-bearing stage, hyphae perfuse both above ground as aerial hyphae and in the soi ...

''; however, all amphenicols are now made by chemical synthesis.

References

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