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Flashcards in Thread Structures Deck (11)
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1
Q

How does the structure of methotrexate differ from that dihydrofolate?

A
  1. No Hydrogen on far left Nitrogen in ring structure. 2. Ketone in far left ring replaced with NH2 group (and now a double bond in ring structure) 3. No hydrogen on bottom N on righthand ring of far left structure (and now another double in ring structure). 4. Methyl instead of hydrogen on central linking Nitrogen.
2
Q

What are the mechanisms of resistance to methotrexate?

A
  1. Mutations to DHFR enzyme, modifies the folate-binding site so that methotrexate no longer binds. 2. Mutli-drug resistance phenotype due to active efflux of drug. 3. Mutations to the reduced folate carrier which prevent methotrexate uptake.
3
Q
A

Lipophillic antifolate - enter cells by passive diffusion

4
Q
A
5
Q
A
6
Q
A
7
Q
A
8
Q

Lipophillic antifolates

A
9
Q

pyrimidine antagonists

A

5-FU

FdURD

Azacytidine

10
Q

Azacytidine

A
11
Q

How does azacytidine differ in structure to cytidine?

A