Purine analogue
Encyclopedia
Purine analogues are antimetabolite
s which mimic the structure of metabolic purine
s.
Antimetabolite
An antimetabolite is a chemical that inhibits the use of a metabolite, which is another chemical that is part of normal metabolism. Such substances are often similar in structure to the metabolite that they interfere with, such as the antifolates that interfere with the use of folic acid...
s which mimic the structure of metabolic purine
Purine
A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....
s.
- AzathioprineAzathioprineAzathioprine is a purine analogue immunosuppressive drug. It is used to prevent organ rejection following organ transplantation and to treat a vast array of autoimmune diseases, including rheumatoid arthritis, pemphigus, inflammatory bowel disease , multiple sclerosis, autoimmune hepatitis, atopic...
is the main immunosuppressive cytotoxic substance. It is widely used in transplantations to control rejection reactions. It is nonenzymatically cleaved to 6-mercaptopurine that acts as a purine analogue and an inhibitor of DNA synthesis. By preventing the clonal expansion of lymphocytes in the induction phase of the immune response, it affects both the cell and the humoral immunityHumoral immunityThe Humoral Immune Response is the aspect of immunity that is mediated by secreted antibodies produced in the cells of the B lymphocyte lineage . B Cells transform into plasma cells which secrete antibodies...
. It also successfully suppresses autoimmunityAutoimmunityAutoimmunity is the failure of an organism to recognize its own constituent parts as self, which allows an immune response against its own cells and tissues. Any disease that results from such an aberrant immune response is termed an autoimmune disease...
. - MercaptopurineMercaptopurineMercaptopurine is an immunosuppressive drug.It is a thiopurine.-Uses:...
- Thioguanine is used to treat acute leukemias and remissions in acute granulocytic leukemias
- FludarabineFludarabineFludarabine or fludarabine phosphate is a chemotherapy drug used in the treatment of hematological malignancies. It has been unofficially and casually referred to as "AIDS in a bottle" amongst healthcare professionals due to its significant immunosuppresive activity.-Indications:Fludarabine is...
inhibits function of multiple DNA polymeraseDNA polymeraseA DNA polymerase is an enzyme that helps catalyze in the polymerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best known for their feedback role in DNA replication, in which the polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand....
s, DNA primase, DNA ligase I and is S phaseS phaseS-phase is the part of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Precise and accurate DNA replication is necessary to prevent genetic abnormalities which often lead to cell death or disease. Due to the importance, the regulatory pathways that govern this...
-specific (since these enzymes are highly active during DNA replication). - PentostatinPentostatinPentostatin is an anticancer chemotherapeutic drug.-Mechanism:It is classified as a purine analog, which is a type of antimetabolite....
and cladribineCladribineCladribine is a drug used to treat hairy cell leukemia and multiple sclerosis. Its chemical name is 2-chlorodeoxyadenosine ....
are adenosine analogs which are primarily used to treat hairy cell leukemiaHairy cell leukemiaHairy cell leukemia is an uncommon hematological malignancy characterized by an accumulation of abnormal B lymphocytes. It is usually classified as a sub-type of chronic lymphoid leukemia...
.