Daniel Jan Strub et al.
Essential oils and aromatic extracts (oleoresins, absolutes, concretes, resinoids) are often used as food flavorings and constituents of fragrance compositions. The flavor and fragrance industry observed significant growth in the sales of some natural materials during the COVID‐19 outbreak. Some companies worldwide are making false claims regarding the effectiveness of their essential oils or blends (or indirectly point toward this conclusion) against coronaviruses, even though the available data on the activity of plant materials against highly pathogenic human coronaviruses are very scarce. Our exploratory study aimed to develop pioneering knowledge and provide the first experimental results on the inhibitory properties of hundreds of flavor and fragrance materials against SARS‐CoV‐2 main and papain‐like proteases and the antiviral potential of the most active protease inhibitors.
The results of this study give the scientific community the selection criteria for further in vitro and in vivo testing of the most promising EOs, AEs, and isolated natural compounds. They can also be used for the rational design of SARS-CoV-2 protease inhibitors. Even though important countermeasures for the spread of SARS-CoV-2 are in motion (i.e., the introduction of vaccines), these results will be important to the field because though coronaviruses can change, the coronaviral proteases are conserved (broad application of results in potential future outbreaks).