Retraction Note to: Discovery of (E)- N-(4-cyanobenzylidene)-6-fluoro-3-hydroxypyrazine-2-carboxamide (cyanorona-20): the first potent and specific anti-COVID-19 drug

[This retracts the article DOI: 10.1007/s11696-021-01640-9.]. © Institute of Chemistry, Slovak Academy of Sciences 2022.