Related Experiment Video
Updated: Aug 8, 2026

Early Viral Entry Assays for the Identification and Evaluation of Antiviral Compounds
Published on: October 29, 2015
Antiviral flavans from the leaves of Pithecellobium clypearia
Yaolan Li1, Kam-Tong Leung, Fenghe Yao
1Department of Chemistry, Jinan University, Guangzhou, Guangdong, People's Republic of China.
Abstract:
Two new antiviral flavan derivatives were isolated from a methanol extract of leaves of Pithecellobium clypearia as guided by antiviral assays. The structures were characterized, by spectroscopic analyses, as 7-O-galloyltricetifavan (1) and 7,4'-di-O-galloyltricetifavan (2). Cytopathic effect (CPE) reduction assay showed that both compounds 1 and 2 possess antiviral activity against respiratory syncytial virus (RSV), with 50% inhibition concentration (IC(50)) values of 5 and 10 microg/mL, respectively; influenza A (H1N1) virus, with IC(50) values of 15.7 and 30 microg/mL; Coxsackie B3 (Cox B3) virus, with IC(50) values of 12.5 and 25 microg/mL, respectively; and Herpes simplex virus type 1 (HSV-1) with IC(50) values of 30 and 20 microg/mL, respectively. Cytotoxicity evaluation using the MTT assay showed that both compounds 1 and 2 were also moderately toxic to several cultured cell lines.
Related Concept Videos
Antiviral Nucleoside Inhibitors
Subviral Agents
Inhibitors of Viral Protein Synthesis
Antifungal Agents
Inhibitors Of Virion Release
Introduction to Plant Diversity

