it is known that these compounds cause inhibition of thymidylate synthetase and , hence , depletion of deoxythymidine triphosphate ( dttp ) and an increased ratio of deoxycytidine triphosphate ( dctp ) to dttp in the deoxyribonucleotide pools that are used for dna synthesis in mammalian cells .
C0040085
thymidylate synthetase
C0598312
dna synthesis