the diphosphate of the antiherpetic agent acyclovir [ 9- [ ( 2-hydroxyethoxy ) methyl ] guanine ] has been shown to inhibit purine nucleoside phosphorylase with unique potency ( tuttle , j. v. , and krenitsky , t. a . ( 1984 ) j. biol . chem . 259 , 4065-4069 ) .
C0001367
acyclovir
C0018321
guanine