Kim JH, Park YI, Hur M, Park WT, Moon YH, Koo SC, Yun-Chan H, Lee IS, Park J. The inhibitory activity of
methoxyl flavonoids derived from Inula britannica flowers on SARS-CoV-2 3CLpro.
Int J Biol Macromol 2022:S0141-8130(22)02237-1. [PMID:
36208809 DOI:
10.1016/j.ijbiomac.2022.10.008]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/26/2022] [Accepted: 10/02/2022] [Indexed: 11/21/2022]
Abstract
In our ongoing efforts to identify effective natural antiviral agents, four methoxy flavonoids (1-4) were isolated from the Inula britannica flower extract. Their structures were elucidated using nuclear magnetic resonance. Flavonoids 1-4 exhibited inhibitory activity against SARS- CoV-2 3CLpro with IC50 values of 41.6 ± 2.5, 35.9 ± 0.9, 32.8 ± 1.2, and 96.6 ± 3.4 μM, respectively. Flavonoids 1-3 inhibited 3CLpro in a competitive manner. Based on molecular simulations, key amino acids that form hydrogen bond with inhibitor 3 were identified. Finally, we found that inhibitors (1-3) suppressed HCoV-OC43 coronavirus proliferation at micromole concentrations.
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