Pharmacologic treatment for herpesvirus infections has targeted the virus-specific enzyme, thymidine kinase (TK ), with nucleoside analogs.
This medicine contains the active ingredient emtricitabine, which is a type of medicine called a nucleoside reverse transcriptase inhibitor.
Attached to the other side of the sugar is a phosphoric acid unit, linking the nucleoside to the neighboring sugar.
However, the unsubstituted nucleosides could lightly yield the fragment ions of the nucleoside base and sugar ring.
The phosphorylation of purine nucleosides to form nucleotides by nucleoside kinase is an alternative pathway of purine salvage.