our approach to overcome the problem of rapid catabolism and general toxicity encountered with 5-halogenated analogues of deoxyuridine ( 5-bromo , chloro or iododeoxyuridine ) , which has limited their use as tumor radiosensitizers , is to utilize 5-chlorodeoxycytidine ( cldc ) with tetrahydrouridine ( h4u ) .
C0011535
deoxyuridine
C0020811
iododeoxyuridine