Viral Infections. steps of Viral Replication, Classification of antiviral agents, Synthesis of Acyclovir

1. Anti-Viral
Presented by :-
Nabi Hasan
ASU2017010100233

3. Viral Infections

4. 1. Adsorption: Attachment of virus to host cell
2. Penetration: Penetration of virus into cell
3. Uncoating: Cell enzymes (lysosymes) strip off the protein coat of virus and expose the
genome
4. Transcription: Production of viral mRNA from the viral genome
5. Translation: viral genome enters the nucleoplasm and utilizes the host nucleic acid
machinery for the synthesis of new viral protein
6. Assembly: New viral coat assembles into capsid and viral genome
7. Release of new virus: release of new viruses after budding and rupture of host cells

7. Therapy

8. Classification of antiviral agents
DNA Polymerase Inhibitors Purine Analogues: Acyclovir, Gancyclovir,
Pyrimidine Analogues: Isoxuridine, Trifluridine
mRNA Synthesis Inhibitors Ribavirin
Amantadine hydrochloride, Rimantadine hydrochlorid
Inhibition of viral penetration and Uncoating
Reverse Transcriptase Inhibitors Zidovudine, Lamivudine, Didanosine
Protease Inhibitors Saquinavir, Indinavir, Ritonavir, Nelfinavir, Amprenavir, Lopinavir
Integration inhibition Zintevir

9. Acyclovir (Purine Analogue)
A widely used antiviral drug especially in the treatment of herpes
Nucleoside Analogue
Guanosine

11. Synthesis of Acyclovir

12. Gancyclovir (Purine Analogue)

13. Idoxuridine
• Idoxuridine is an anti-herpesvirus antiviral drug. It is a nucleoside analogue
• Idoxuridine is first phosphorylated by the host cell to an active triphosphate form
• The phosphorylated drug is incorporated during viral nucleic acid synthesis by a false
pairing system that replaces thymidine, this results in chain termination

14. Amantadine hydrochloride Rimantadine hydrochloride

15. Para-amino salicylic acid
It inhibits bacterial folate pathway

16. Second-Line Drugs
Rifabutin
Structurally and mechanistically similar to Rifampacin

17. Cycloserine
• An antibiotic obtained from Streptomyces Orchidaceus
• It is an analogue of D-alanine
• Inhibit cell wall synthesis

18. Streptomycin
• An antibiotic obtained from Streptomyces griseus
• It is first clinically useful anti-tubercular Drug
• Acts only on extracellular bacilli
• It inhibits protein synthesis by binding with 30S unit of ribosome
Capreomycin sulphate
• An antibiotic obtained from Streptomyces capreolus
• Inhibit protein synthesis

19. Thank You