39809-25-1 6H-Purin-6-one, 2-amino-1,9-dihydro-9-(4-hydroxy-3-(hydroxymethyl)butyl)- 9-(4-Hydroxy-3-(hydroxymethyl)butyl)guanine 97845-62-0 BRL 39123 Denavir Penciclovir Penciclovir [USAN:BAN:INN] Penciclovirum [INN-Latin]