2. Acridines
• Aacridine is formed when an additional benzene
ring is fused with pyridine ring of quinoline
nucleus. Acridine is overall aromatic, though
having nitrogen
Pyridine
Quinoline Benzene
3. 9-Amino acridine
• has an amino group at C -9
• It is a green fluorescent dye
• In the past, the compound was used as an
antiseptic for treating wounds infections
4. Structure Activity Relationship
• Various types of acridines were synthesized
• Acridine has weak antiseptic and antibacterial
activity
• When a side chain – 2 amino, 5 diethylamino
pentane- is introduced at C-9, the compound
becomes antimalarial
• When methoxy at position 2 and Cl at 6 are
introduced –quinacrine- which is antimalarial
• Quinacrine was the 1st synthetic agent that
was used before quinolines
6. • When methoxy is shifted to position 6 and Cl to
2 (interchanged)-loss of antimalarial activity
• When methoxy is replaced by ethoxy, toxicity is
increased
• When methoxy is rotated to any other position
1, 3, 4, then 50% activity is lost
• When Cl is replaced with other halogens there is
successive loss of activity
7. • Side chain – 2 amino, 5 diethylamino pentane-
has no antimalarial activity but when attached
to aromatic system the compound became
antimalarial
• When at position-1, a N is introduced –
azacrine- which has good antimalarial activity
and rapid onset of action
16. Therapeutic uses
• Treating erythrocytic stage of malaria
• Earlier, was used in treating black water fever
• Have anthalmentic activity against intestinal
parasites
• It is eliminated slowly and have side effects
17. Non-therapeutic use
• Being green fluorescent dye, used to visualize
blood cells, particularly platelets
• Platelets store the dye in dense granules