Drugs which interact with DNA Flashcards
1
Q
How do nucleic acids act as targets for drugs (10)
A
- Antimetabolites interact with nucleic acids by blocking normal metabolic pathways by:
- Replacing an endogenous compound with another resulting in a product which cannot continue in the pathway
- Inhibiting an enzyme in the metabolic pathway
- anti-folates interfere with the process of converting folic acid into tetrahydrofolate, inhibiting DNA synthesis and preventing cell replication.
- purine antimetabolites inhibit DNA synthesis by inhibiting several enzymes in purine biosynthesis
- pyrimidine antimetabolites work by inhibiting DNA synthesis by inhibiting several enzymes in purine biosynthesis.
- Enzyme inhibitors inhibit transcription by inhibiting topoisomerases, which are enzymes responsible for the supercoiling, cleavage and rejoining of DNA. the conversion of uridine monophosphate (UMP) to other pyrimidine nucleotides– and have antitumour action.
- Intercalating agents insert themselves between the bases of the DNA helix which, causes the DNA helix to unwind partially and inhibits transcription.
- Alkylating agents covalently bond to nucleic acid chains and frequently form intrastrand or interstrand cross-links – inhibit transcription.
- Chain-cleaving agents result in the breaking of nucleic acid into fragments. The exact mechanism of action is uncertain.
2
Q
What is an anti-folate (metabolite) drug example
A
methotrexate
3
Q
What is a purine antimetabolite drug example
A
6-mercaptopurine
4
Q
What is a pyrimidine antimetabolite drug example
A
5-fluorouracil
5
Q
What is an enzyme inhibitor drug example
A
Lisinopril
6
Q
What are an intercalating agents drug examples (2)
A
anticancer agents mitoxantrone and doxorubicin
7
Q
What are alkylating agents drug examples (2)
A
nitrogen mustards such as Mustine
pro-electrophiles such as temozolomide.
8
Q
What is a chain-cleaving agent drug example
A
bleomycin
