Pharmaceutical Potential of Pyrimidines as Antiviral Agents

Antiviral drugs are a class of medicines particularly used for the treatment of viral infections. Drugs that combat viral infections are called antiviral drugs. Viruses are among the major pathogenic agents that cause a number of serious diseases in humans, animals and plants. Viruses cause many diseases in humans, from self-resolving diseases to acute fatal diseases. The strategies for the development of antiviral drugs are generally focused on two different approaches, i.e., targeting the viruses themselves or the host cell factors. Antiviral drugs that directly target viruses include the inhibitors of virus attachment, inhibitors of virus entry, uncoating inhibitors, polymerase inhibitors, protease inhibitors, nucleotide reverse transcriptase, inhibitors of nucleoside and the inhibitors of integrase. The inhibitors of protease (ritonavir, atazanavir and darunavir), viral DNA polymerase (acyclovir, tenofovir, valganciclovir and valacyclovir) and integrase (raltegravir) are listed among the top 200 drugs by sales during the2010. Still, there are no effective antiviral drugs available for many viral infections. There is a couple of drugs for herpes viruses, many for influenza and some new antiviral drugs for treating hepatitis C infection and HIV. This chapter gives an overview of the pyrimidines and hetero annulated pyrimidines that have been reported to be active against viral infections; identification of novel pyrimidine leads may be used in the designing of new potent, selective and less toxic novel therapeutic agents having promising antiviral activity. An effort has been made to compile all the possible information regarding antiviral pyrimidines and bring them together to make easy availability of the existing literature on the subject. The objective of this chapter is to provide the structural and antiviral activity information as well as methods being used for the screening of the antiviral activity and antiviral potential IC50/ED50/CC50 values of the reported active pyrimidines are briefly discussed.

Keywords: Antiviral drugs, Antiviral pyrimidines, Inhibitory actions, Mechanisms of action.