You can watch this lecture on youtube https://www.youtube.com/watch?v=7_oFbKXamac Complete Chapter of Anti-malarial Drugs Part -1 Introduction -Stages Of Malaria -Chemical classification -SAR of Anti-Malarial Drugs

1. Complete Chapter of
Anti-malarial Drugs Part -1
-Introduction
-Stages Of Malaria
-Chemical classification
-SAR of Anti-Malarial Drugs
B. Pharm 6th
Semester &
Pharm.D 3rd Year

2. Malaria is one of the most widespread diseases.
The causative agent is a group of parasitical protozoa of the
Plasmodium genus transmitted by the female Anopheles mosquito.
Its original treatment was quinine that became the prototypical
molecule for the first generation of synthetic antimalarial drugs.
One of the most effective preventions is controlling the mosquito
population that is the vector carrying the parasite to humans.
Introduction

3. Malaria is caused by four species of the one-cell protozoan of the Plasmodium
genus.
Plasmodium falciparum: This species is estimated to cause approximately 50%
of all malaria. It causes the most severe form of the disease . it infects up to
65% of the patient’s erythrocytes.
Plasmodium vivax: This species is the second most common species causing
about 40% of all malarial cases. It can be very chronic in recurrence because it
can re-infect liver cells.
Plasmodium malariae: Although causing only 10% of all malarial cases, relapses
are very common.
Plasmodium ovale: This species is least common.

5. Chemical Classification
1. Cinchona alkaloids

6. 2. 4-Aminoquinolines

7. 2. 4-Aminoquinolines(Continue………….)

8. 2. 4-Aminoquinolines(Continue………….)

9. 3. 8-Aminoquinolines

10. 3. 8-Aminoquinolines(Continue………..)

11. 3. 8-Aminoquinolines(Continue………..)
Tafenoquine

12. 4. Polycyclic Antimalarial Drugs
Doxycycline

13. 4. Polycyclic Antimalarial Drugs(Continue….)

14. 5. Artemisinin and artemisinin-derived compounds.

15. 6. 9-Amino acridine

16. 7. Biguanides
Cycloguanil

17. 8. Naphthoquinones

18. 9. Pyrimidine analogue 10. Sulfonamide analogue

19. 11. Fosmidomycin analogue

20. Site of Action of Anti-Malarial Drugs

22. SAR of Anti-Malarial Drugs

24. Alkyl Side chain
R=-CH2-(CH2)1-5-N(C2H5)2

25. SAR of 8-Amino quinoline
1. Introduction of OCH3 group at 6th Position increases the activity.
2. If -OCH3 Group is replaced by -OC2H5 ,the compound became less active and more toxic in
nature.
3. If -OCH3 is replaced by CH3 the compound became inactive.
4. Presence of quinoline ring is necessary for antimalarial activity.
5. When pyridine ring is converted to piperidine (saturated) the compound became inactive.
6. When side chain is introduced at amino group at position 8 the antimalarial activity increases.
7. Introduction of halogens increases toxicity.
8. Pentyl side chain gives maximum activity, increase or decrease of chain result is reduction of
activity.
9. The branched side chain when converted into straight chain pentaquine is obtained, It has less
antimalarial activity as compared to both pamaquine and primaquine.

26. SAR of Artemisinin
1. Tetracyclic structure with a trioxane ring and a lactone
ring.
2. Trioxane ring contains a peroxide bridge, the active
moiety of the molecule.
3. Presence of a ‘Trioxane’ moiety which consists of the
Endoperoxide & Doxepin oxygens that is evidently
displayed by a simplified version of 3- Aryltrioxanes.

27. 4. Reduction of Artemisinin to Dihydroartemisinin gives rise to a chiral
centre,that may ultimately lead to the formation of ‘Prodrugs’ which could
either be oil soluble or water soluble.
5. Like the simpler Aryltrioxanes the two prevailing stereoisomers Artemether,
Artesunate which are found to be active.
6. 1,2,4 trioxane ring had a potency greater than Artemisinin itself but lacked
stability in vivo.
7. Ether substituted drugs, Artemether & Arteether are
oil soluble & can be administered i/m & converted to
dihydroartemisinin in vivo.