Fig. 1
From: Cyclization-blocked proguanil as a strategy to improve the antimalarial activity of atovaquone
Schematic showing metabolism of proguanil to cycloguanil. a Proguanil (1) is metabolised to form the cyclization product cycloguanil (4) and the hydrolysis product 4-chlorophenylbiguanide (5). b Due to the lack of a methine proton in tBuPG (6), it is unable to undergo oxidative transformation into imine (3) and therefore cannot produce cycloguanil (4)
