This powerpoint presentation will help to know about introduction of bioisosterism by Biotechnology point of view. Hope this powerpoint presentation will your reference.
4. BIOISOSTERES- Burger defines, “substitute or groups
with chemical or physical similarities
Produce similar biological properties
Replacement or modification of functional group with
other having similar properties called bioisosteric
replacement
5. Why isosteric replacement?
Greater selectivity
Less side effects
Deceased toxicity
Improved pharmacokinetics
Increase stability
6. UTILITY OF BIOISOSTERES
Improving potency
Enhancing selectivity
Altering physical properties
Reducing or redirecting metabolism
Eliminating or modifying toxicophores
Acquiring novel intellectual property
8. Classical bioisosteres are further classified:
Univalent atoms and groups (C, N, O, S, -Cl, -Br)
Bivalent atoms and groups (R-O-R, R-S-R, R-NH-R)
Trivalent atoms and groups (-CH=, -N=, R-N=R)
Tetravalent atoms and groups (=C=, =N=, =P=)
Ring equivalent
9. Non – classical bioisosteres don’t have same number
of atoms
It don’t fit for steric and electronic rules
But produce similar biological activity
a) Halogens (Cl, F, Br)
b) Ethers (-R-O-R, -S-)
c) Hydroxy groups (-OH)
d) Carboxylic acid group (-R-COOH, R-SOOH)
e) Catechol
10. CHANGES OCCUR:
Some changes resulting from bioisosteric replacement
1. Structural (size, shape, H-bonding)
2. Receptor interactions (lipid or water solubility)
3. Pharmacokinetics (lipophilicity, hydrophilicity, Pka, H-
bonding)
11. For example;
Cyclopropyl group used as bioisosteric for an alkaline
group in prodrugs and opioid antagonists
Replacing a functional group, important for target binding,
but problematic on one way or other
For example, thiourea group was present as important
binding group in early histamine antagonist but was
responsible for toxic side effects
replacing it with bioisosteric allow binding without
toxicity
12.
13. REFERENCE
Prof. S.V. Amrutkar slideshare in SCRIBD
www.tubakhanslideshare//slideshare.com
Graham L.Patrick book An introduction to medical
chemistry