Antiviral Drugs Nucleoside and Nucleotide Analogs 0 0 C- Guanine HN c一N HN C一N CH CH H2N-C-N C-N NN-CN一CN HOCH2 HOCH2 H H H HO H Deoxyguanosine Acyclovir (a)Structural resemblance between acyclovir and guanine-containing nucleoside Figure 20.16aAntiviral Drugs Nucleoside and Nucleotide Analogs Figure 20.16a