Structure, Mechanism of action and Uses of Chloramphenicol

 

Chloramphenicol: Structure, Mechanism of Action, and Uses

Structure:

Chloramphenicol is an antibiotic with a chemical structure consisting of:

• A nitrobenzene ring.
• Two hydroxyl groups (-OH) attached to a propanediol chain.
• A dichloroacetyl side chain (CCl₂).

The IUPAC name of chloramphenicol is: 2,2-Dichloro-N-[1,3-dihydroxy-1-(4-nitrophenyl)propan-2-yl]acetamide.

Mechanism of Action:

Chloramphenicol inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. Specifically, it prevents the peptidyl transferase enzyme from adding new amino acids to the growing peptide chain, thereby halting the translation process. This action is bacteriostatic (stops bacterial growth) and can be bactericidal (kills bacteria) in certain species depending on the concentration.

Chloramphenicol is effective against a wide range of gram-positive and gram-negative bacteria, including anaerobes. However, its use is limited due to potential severe side effects.

Uses:

Chloramphenicol is used to treat serious bacterial infections where other antibiotics might be ineffective or contraindicated, including:

• Typhoid fever (caused by Salmonella typhi).
• Bacterial meningitis (particularly in cases where penicillin cannot be used).
• Eye infections (as an ointment or eye drops for bacterial conjunctivitis).
• Rickettsial infections (like Rocky Mountain spotted fever).

It is often reserved for serious infections due to the risk of bone marrow suppression (aplastic anemia).

Structure of Chloramphenicol:

Below is the structure of chloramphenicol, showing its nitrobenzene ring, hydroxyl groups, and dichloroacetyl group:

    Cl     O

    |     ||

H2N-C-CH(OH)-CH(OH)-C6H4-NO2

    |

    Cl

The structure represents a dichloroacetyl amide group attached to a hydroxylated propanediol chain, with a nitro-substituted benzene ring.

This antibiotic is used cautiously in clinical settings, given its potency and side effects, making it a critical option when treating resistant or life-threatening infections.