Transcript No Slide Title

Patrick
An Introduction to Medicinal Chemistry 3/e
Chapter 22
ANTIULCER AGENTS
Part 2: Helicobacter pylori
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Contents
Part 2: Helicobacter pylori
21. Features of H. pylori (3 slides)
22. Treatment of H. pylori
[5 slides]
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21. Features of H. pylori
•
Spiral, curved bacterium
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Grows best in oxygen concentrations of 5%
•
Naturally present in the stomachs of many people
•
Attaches to a sugar molecule on the surface of the cells lining
the stomach wall
•
The organism secretes proteins and toxins that inflame the
stomach lining
•
Responsible for the recurrence of esters
•
The organism is protected by the mucus layer
•
A pH gradient across the mucus layer means that the pH is near
neutral at the stomach lining
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21. Features of H. pylori
Stomach contents
pH = 2
Mucus layer
pH = 4
H. pylori
pH = 7
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21. Features of H. pylori
•
Bacterium produces urease enzyme
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Neutralises any acid in the local environment
O
H2N
Ure a
Ure ase
2 NH3 +
NH2
CO2
H2O
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22. Treatment of H. pylori
•
•
Triple therapy of a proton pump inhibitor and two antibiotics
Antibiotics work better at a higher pH than is normally present
in stomach
The proton pump inhibitor is present to raise the pH
•
Example
OH
NH2
O
N
OMe
H
N
S
S
N
H
Me
MeO
N
HO
N
Me
N
O
O
Me
Omeprazole
O2N
Amoxicillin
CO2H
N
Metronidazole
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