Penicillin Antibiotic Chemistry

1. CHEMISTRY OF PENICILLIN
 BY- ROHIT PESHANE
B- PHARM 6TH SEMISTER
ANURAR COLLEGE OF PHARMACY
WARTHI BHANDARA

2. CONTENTS:
BETA-LACTAM ANTIBIOTICS
HISTORY OF PENICILLIN
NOMENCLATURE OF PENICILLINS
STEREOCHEMISTRY OF PENICILLIN
CLASSIFICATION OF PENICILLIN

3. BETA-LACTAM ANTIBIOTICS :
Antibiotic Defination:
Antibiotics are the chemical substances produced by
microorganism, which at high dilution can inhibit the
growth or multiplication or kill the other microorganism.
Waskman and woodruff coin the the term antibiotic in 1942.
Beta-antibotics :
1) Cyclic amide is called as lactam.
2) Beta position of cyclic amide contain
nitrogen atom, hence it is called as
beta-lactam ring.
3) Four membered cycling ring is also
known as azetidine ring hence beta-
lactam ring is also known as
azetidinone ring

4. Beta-lactam Antibiotic :
Beta-lactam antibioticsincludesfollowing
Classes:-
1. Penicillin
2. Cephalosporin
3. Beta-lactamase inhibitors
4. Monobactams

5. Penicillin :-
 Penicillin is a fussion of two rings that is
beta-lactam ring and thiazolidinering.
 Penicillin is the frist antibioticsused in
mens.

6. History of penicillin:-
 Penicillin the wrolds frist antibiotic was accidentally discovered by British
scientist Alexander Flemmingin 1928.
In 1928 Alexandar Flemming discovered the compound produced by the
fungus.
 The fungusis known as penicillin notatum.
 Flemming noted that a fungusgrowing on his bacterial plate had killed off
the surroundig bacteria.
 In 1939 during second wrold war Howard Florey and Ernst Chain at oxfard
England started research and Penicillin G are avialable for theraupetic trial
in 1941.
 Flemming ,Florey and Chain recived a Nobel Prize In 1945 for
Medicine for their work on penicillin.
 The bio-synthesisof penicillin upto1958 to 1959 depend upon the penicillin
notatum and penicillin chrysogenum in deep vat culture.
 Later the culture technique and extractiontechniqueare modified.

7. Nomenclature of Penicillin :-
 The nomenclature of penicillin are done by two systems :-
1.Chemical Abstract System:
According to chemical abstract system sulfer atom is assigned 1st
position and nitrogen atom assigned the 4th position and compound is
called as 1-thia-4aza-bicyclo(3.2.0)–heptanes.
2. USP System:
USP system is the reverse of chemical abstract system.
In which the nitrogen aton assign the 1st position and sulfer atom
assigned the 4th position hence the compound is called 1-aza-4thia-
bicyclo(3.2.0)-heptanes.

8. Nomenclature of penicillin :
There are three form for nomenclature of penicillin;
(1).The frist form uses the the name penam for the
unsubstituted bicyclo system including
group.
amide crbonyl
According this form thre penicillin are named as 5-
acylamino-2,2dimethyl penam-3-carboxylic acid.
(2).The second form uses the name penicillanic acid .
Penicillanic acid is a penam that consist of 3-3dimethyl -7-
oxo-4-thia-1-azabicyclo(3.2.0)heptane bearing a
carboxylic group at 2nd position.

9. Nomenclature of penicillin
(3)The third form is the trivial system.
In this system 6-carbonyl amino penicillanic acid portion of the
molecule is known as the penicillin and the different penivillin are
distinguished on the basis of R group on the acyl amino side chain.
IUPAC NAME:-
2S,5R,6R,-3-3dimethyl-7-
oxo-6[(2-benzylamino)]-1-
aza-4-thia-
bicyclo[3.2.0]heptane-2-
CarboxylicAcid.

10. Nomenclature of Penicillin :

11. Stereochemistry of penicillin :
 The penicilin molecule contain three chiral carbon atoms
5)and (C-6).
(C-2),(C-
 All the naturally occuring and synthetic and semisynthetic penicillin
have the same absolute configurationat three chiral center.
 The carbon atom bearing the Acylaminogroup (c-6)has the
L- configuration whereas the carbon to which carboxylic group are
attached has the D- configuration.
 Thus the Acylamino and carboxyl group are trans to each other.
 The atom comprising the 6-amino penicillanic Acid portion is derived Bio-
syntheticaly from two amino acids ,L-cystiene ( S-1,C-5,C-6 C-7 and
6- amino) and L-valine (3,3dimethyl,C-2,C-3,N-4 and 2 carboxyl).
 The absolute stereochemistry of the penicillin is 2:S5:R6:R .

12. Classification of Penicillin :
(1)Acid-resistance alternative to penicillin G :
Eg.Phenoxymethyl penicillin (penicillin V )
(2)Penicillinase-resistance Penicillins
Eg.Methicillin, Cloxacillin, Dicloxacilin
(3)Extended spectrum penicillins
(a)Aminopenicillins:Ampicillin,Bacampacillin,Amoxicillin.
(b)Carboxypenicillins: Carbepenicillin.
(c)Ureidopenicillins:Piperacillin, Mezlocillin.
Beta-lactamase inhibitors : Clavulanic acid, Sulbactam,

13. THANK
YOU