Detail chemistry of Chloramphenicol

1. Glimpses of Other Antibiotic :
Medicinal Chemistry III
Ms. Mandakini S.Holkar
(M. Pharm.)
For Third Year B. Pharm. Program as per
PCI syllabus, New Delhi

2. Chloramphenicol
Chloramphenicol was discovered after being isolated from
Streptomyces venezuelae in 1947.
It contains chlorine and is obtained from an actinomycete, and thus,
named as Chloromycetin.
Chloramphenicol is an broad spectrum antibiotic useful for the
treatment of a number of bacterial infections.
The most serious adverse effect of chloramphenicol is bone marrow
depression
It is specifically recommended for the treatment of serious infections
caused by H. influnzae, S. typhi (typhoid), S. pneumoniae,

4. SAR of Chloramphenicol
1. SAR of p-nitrophenyl group:
a. Replacement of the nitro group by other substituent’s reduction in
activity.
b. Shifting of the nitro group from the para position also reduces the
antibacterial activity.
c. Replacement of phenyl group by alicyclic moieties results in less potent
compounds.
d. The p-nitrophenyl groups may be replaced by other aryl structures without
appreciable loss of activity.

5. 2. SAR of dichloroacetamido side -chain:
a. Other dihaloderivatives of the side-chain sligjtly less active
b. In case of trihaloderivatives claimed that 2 NHCOCF3 derivtive
1.7 times as active as chloramphenicol.

6. 3. SAR of 1,3-propanediol :
a. The primary alcoholic group on C1 atom if modified decrease in
activity hence alcoholic group essential for activity
b. Stereochemistry of side chain is essential for activity.

7. Reference:
 Willams and Thomas L.Lemke Foye’s Principles of
Medicinal Chemistry Fifth edition
 Rang H.P. and Dale M.M.: Pharmacology, Churchill
Livingstone, Edinbergh.
 Dr.S.S.Kadam and K.R.Mahadik Principles of
Medicinal Chemistry Volume -I

8. msholkar@cop.sveri.ac.in