Structure-activity relationship studies on novel antiviral agents for norovirus infections

Ferla, Salvatore ORCID: https://orcid.org/0000-0002-5918-9237, Varricchio, Carmine ORCID: https://orcid.org/0000-0002-1673-4768, Knight, William, Ho, Pui Kei, Saporito, Fabiana, Tropea, Beatrice, Fagan, Giulio, Flude, Ben Matthew, Bevilacqua, Federica, Santos-Ferreira, Nanci, Van Dycke, Jana, Neyts, Johan, Brancale, Andrea ORCID: https://orcid.org/0000-0002-9728-3419, Rocha-Pereira, Joana and Bassetto, Marcella ORCID: https://orcid.org/0000-0002-2491-5868 2021. Structure-activity relationship studies on novel antiviral agents for norovirus infections. Microorganisms 9 (9) , 1795. 10.3390/microorganisms9091795

PDF - Published Version Available under License Creative Commons Attribution. Download (897kB)

Abstract

Human norovirus is the leading cause of acute gastroenteritis worldwide, affecting every year 685 million people. Norovirus outbreaks are associated with very significant economic losses, with an estimated societal cost of 60 billion USD per year. Despite this, no therapeutic options or vaccines are currently available to treat or prevent this infection. An antiviral therapy that can be used as treatment and as a prophylactic measure in the case of outbreaks is urgently needed. We previously described the computer-aided design and synthesis of novel small-molecule agents able to inhibit the replication of human norovirus in cell-based systems. These compounds are non-nucleoside inhibitors of the viral polymerase and are characterized by a terminal para-substituted phenyl group connected to a central phenyl ring by an amide-thioamide linker, and a terminal thiophene ring. Here we describe new modifications of these scaffolds focused on exploring the role of the substituent at the para position of the terminal phenyl ring and on removing the thioamide portion of the amide-thioamide linker, to further explore structure-activity relationships (SARs) and improve antiviral properties. According to three to four-step synthetic routes, we prepared thirty novel compounds, which were then evaluated against the replication of both murine (MNV) and human (HuNoV) norovirus in cells. Derivatives in which the terminal phenyl group has been replaced by an unsubstituted benzoxazole or indole, and the thioamide component of the amide-thioamide linker has been removed, showed promising results in inhibiting HuNoV replication at low micromolar concentrations. Particularly, compound 28 was found to have an EC50 against HuNoV of 0.9 µM. Although the most active novel derivatives were also associated with an increased cytotoxicity in the human cell line, these compounds represent a very promising starting point for the development of new analogues with reduced cytotoxicity and improved selectivity indexes. In addition, the experimental biological data have been used to create an initial 3D quantitative structure-activity relationship model, which could be used to guide the future design of novel potential anti-norovirus agents.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Pharmacy
Additional Information:	This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Publisher:	MDPI
ISSN:	2076-2607
Date of First Compliant Deposit:	1 September 2021
Date of Acceptance:	17 August 2021
Last Modified:	07 Jan 2024 03:18
URI:	https://orca.cardiff.ac.uk/id/eprint/143809

Actions (repository staff only)

Edit Item