creators_name: Hoque, Israful
creators_name: Singh, Nittu
creators_name: Ghosh Dastidar, Uddipta
creators_name: Martin, Alna Kuriyickal
creators_name: Joshi, Akshay
creators_name: Sardana, Yogesh
creators_name: Singh Chawla, Ravneet
creators_name: Das, Nirmal
creators_name: Patra, Binita
creators_name: Devi, Renuga
creators_name: Das, Satyajeet
creators_name: Das, Dipankar
creators_name: Kumar, Sahil
creators_name: Ringe, Rajesh P
creators_name: Bokara, Kiran Kumar
creators_name: Thakur, Krishan Gopal
creators_name: Talukdar, Arindam
type: article
datestamp: 2026-02-01 14:20:54
lastmod: 2026-02-01 14:20:54
metadata_visibility: show
title: Strategic design and optimization of Umifenovir analogues: Balancing antiviral efficacy and hERG toxicity against SARS-CoV-2
abstract: Arbidol (ARB, Umifenovir), a broad-spectrum antiviral from Russia, lacks Food and Drug Administration (FDA) approval due to insufficient clinical data and undocumented toxicity concerns. Its indole scaffold, with six unique substitutions, enables optimization for improved efficacy. This study optimized ARB's antiviral potency and safety by modifying the N1, C2, C3, and C4 positions. Antiviral efficacy was evaluated in SARS-CoV-2-infected VERO E6 cells, while optimization was guided by absorption, distribution, metabolism, and excretion (ADME), in vivo pharmacokinetic (PK) and hERG. Early modifications at N1 and C2 produced compounds 10 and 14 (IC50 = 1.5 μM), surpassing ARB (IC50 = 9.0 μM). Further refinements yielded compounds 42 (IC50 = 1.1 μM) and 56 (IC50 = 0.24 μM), resolving hERG toxicity (>30 μM). C3 modifications led to lead compounds 77, 79, and 81 (IC50 = 0.67-0.7 μM), achieving superior potency while eliminating hERG toxicity. Mechanism of entry inhibition and immunofluorescence confirmed compound 77 significantly reduced SARS-CoV-2 within Vero cells, supporting their preclinical potential.
date: 2025-05
publication: J. Med. Chem.
volume: 68
number: 9
publisher: American Chemical Society (ACS)
pagerange: 9371-9406
citation:   Hoque, Israful and Singh, Nittu and Ghosh Dastidar, Uddipta and Martin, Alna Kuriyickal and Joshi, Akshay and Sardana, Yogesh and Singh Chawla, Ravneet and Das, Nirmal and Patra, Binita and Devi, Renuga and Das, Satyajeet and Das, Dipankar and Kumar, Sahil and Ringe, Rajesh P and Bokara, Kiran Kumar and Thakur, Krishan Gopal and Talukdar, Arindam  (2025) Strategic design and optimization of Umifenovir analogues: Balancing antiviral efficacy and hERG toxicity against SARS-CoV-2.  J. Med. Chem., 68 (9).  pp. 9371-9406.