Antiviral Activities of Pyridine Fused and Pyridine Containing Heterocycles, A Review (from 2000 to 2020)

Heterocyclic compounds play a critical role in medicinal chemistry and many available drugs contain heterocyclic rings. A six-membered heterocyclic compound pyridine showed various applications that acts as an important solvent, reagent, and precursor in agrochemicals and pharmaceuticals. Due to the increase of drug resistance, there is an obvious medical need to develop new antiviral agents. Various derivatives of pyridine scaffold display abroad biological activities such as anti-microbial, anti-viral, antioxidant, anti-diabetic, anti-cancer, anti-malaria, analgesic and anti-inflammatory activities, psychopharmacological antagonistic, anti-amoebic agents, and anti-thrombic activity. Due to the high importance of pyridine derivatives, in the present review, we tried to collect and classify many pyridine derivatives based on their structures from 2000 to 2020. Pyridine derivatives were classified into two general categories including pyridine containing heterocycles and pyridine fused rings. Structure-activity relationship (SAR) and the action mechanism of derivatives were also investigated. According to the recent studies, these derivatives exhibited good antiviral activity against different types of viruses such as the human immunodeficiency viruses (HIV), the hepatitis C virus (HCV), the hepatitis B virus (HBV), Respiratory syncytial virus (RSV), and Cytomegalovirus (CMV). These derivatives inhibited viral application with different action mechanism such as RT inhibition, polymerase inhibition, Inhibition of RNase H activity, inhibition of maturation, inhibition of the viral thymidine kinase, AAK1 (Adaptor-Associated Kinase 1) inhibition, GAK (Cyclin G-associated kinase) inhibition, inhibition of post-integrational event, inhibition of HDAC6, CCR5 antagonistic activity, DNA and RNA replication inhibition, gene expression inhibition, cellular NF-jB signaling pathway and neuraminidase (NA) inhibition, protein synthesis inhibition, and generally inhibition of viral replication cycle. This paper summarily expressed the past and present results about the discovery of novel lead compounds with good antiviral activity. Studies exhibited that almost all of the evaluations were performed by way of in vitro testing and is necessary to investigate in vivo and clinical testing for having better evaluations in the future. We believe that pyridine derivatives can be used as promising antiviral agents and needs to perform more broad investigations in this field.