Pharma & Specialty Chemical Standards

Aciclovir (IUPAC name: 9-(2-hydroxyethoxymethyl)guanine) is a guanine nucleoside analog with molecular formula C8H11N5O3 and molecular weight 225.2 g/mol. It features a modified sugar moiety, where a hydroxyethyl group replaces the typical ribose structure. Therapeutically, it targets herpesvirus infections (HSV-1, HSV-2, VZV). Physicochemically, it is a white crystalline solid, water-soluble (pKa ~2.5), and exhibits low oral bioavailability. Mechanism of action involves phosphorylation by viral thymidine kinase, forming aciclovir triphosphate, which competitively inhibits viral DNA polymerase, causing chain termination during DNA synthesis. Its selectivity arises from preferential phosphorylation by viral enzymes over host enzymes.