NCIt definition : The hydrochloride salt form of proguanil, a synthetic biguanide derivative of pyrimidine
and an folate antagonist with antimalarial property. Upon hydrolysis, proguanil is
converted to its active cyclic triazine metabolite, cycloguanil, by a cytochrome P450
dependent reaction. Cycloguanil selectively inhibits the bifunctional dihydrofolate
reductase-thymidylate synthase (DHFR-TS) of plasmodium parasite, thereby disrupting
deoxythymidylate synthesis and ultimately blocking DNA and protein synthesis in the
parasite.;