Which of the following antitumor agents works by impairing de novo purine synthesis? (Delhi PG 2010)
De novo synthesis refers to the synthesis of complex molecules from simple molecules such as sugars or amino acids, as opposed to their being recycled after partial degradation.
· Methotrexate and pemetrexed are the inhibitors of dihydrofolate reductase (DHFRase).
· These drugs also inhibit Thymidylate synthase (TS) and the enzymes involved in early purine synthesis like glycinamide ribonucleotide formyltransferase (CART).
· These drugs are thus involved in inhibiting the denovo purine synthesis.