Related Experiment Video
Updated: May 26, 2025

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
Pyrazolo[3,4-d]pyrimidine-based neplanocin analogues identified as potential de novo pharmacophores for dual-target
Mohan Kasula1,2, Masaaki Toyama3, Ramakrishnamraju Samunuri2,4
1Department of Chemistry, Forbesganj College, Purnea Univeristy-854318 India kasula.mohan@gmail.com.
Abstract:
The discovery of selective and potent inhibitors through de novo pathways is essential to combat drug resistance in chronic hepatitis B (CHB) infections. Recent studies have highlighted that neplanocin A (NepA) derivatives are biologically selective inhibitors of the hepatitis B virus (HBV). In this study, we designed, synthesized, and evaluated various pyrazolo[3,4-d]pyrimidine-based NepA analogues (4a-h) for their anti-HBV activity. Notably, analogue 4g demonstrated significant activity against HBV replication, with EC50 (HBV DNA) = 0.96 μM, CC50 > 100 μM and EC50 (HBsAg) = 0.82 μM, showing selective inhibition of HBsAg secretion. The SAR analysis concluded that replacing the polar 4-NH2 group with -CH3 also acted as a weak H-bonding donor, and the presence of 3-iodo was found to be desirable for the activity/toxicity profile. The nucleoside analogues exhibited a distinct mechanism of action compared to existing nucleoside analogues for the selective inhibition of HBsAg secretion. Based on these findings, compound 4g represents a promising lead molecule for the development of new anti-HBV agents with unique mechanisms of action.
Related Concept Videos
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Basicity of Heterocyclic Aromatic Amines
Nomenclature of Aryl and Heterocyclic Amines
Five-Membered Heterocyclic Aromatic Compounds: Overview
Diazonium Group Substitution: –OH and –H
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
