Supplemental online material Antiviral activity of curcumin and its analogs selected by an artificial intelligencesupported activity prediction system in SARS-CoV-2-infected VeroE6 cells
Koji Teshima, Takeshi Tanaka, Zhengmao Ye, Ken Ikeda, Takao Matsuzaki, Tamotsu Shiroma, Ayumu Muroya, Masato Hosoda, Mayo Yasugi, Hirotsugu Komatsu
Curcumin has been reported to exert its anti-SARS-CoV-2 activity by inhibiting the binding of spike receptor-binding domain (RBD) to angiotensin-converting enzyme-2 (ACE2). To identify more potent compounds, we evaluated the antiviral activities of curcumin and its analogs in SARS-CoV-2-infected cells. An artificial intelligence-supported activity prediction system was used to select the compounds, and 116 of the 334 curcumin analogs were proposed to have spike RBD-ACE2 binding inhibitory activity. These compounds were narrowed down to eight compounds for confirmatory studies. Six out of the eight compounds showed antiviral activity with EC50 values of less than 30 µM and binding inhibitory activity with IC20 values of less than 30 µM. Structure-activity relationship analyses revealed that the double bonds in the carbon chain connecting the two phenolic groups were essential for both activities. X-ray co-crystallography studies are needed to clarify the true binding pose and design more potent derivatives.
Cells African green monkey kidney cell line VeroE6 and VeroE6 expressing the transmembrane serine protease TMPRSS2 (VeroE6/TMPRSS2, Matsuyama et al. 2020) were purchased from the National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan. VeroE6 cells were cultured in minimal essential medium (MEM; Sigma-Aldrich, MO, USA) supplemented with 10% fetal bovine serum (FBS) and antibiotics. VeroE6/TMPRSS2 cells were cultured in Dulbecco's modified Eagle's medium (DMEM; Thermo Fisher Scientific, MA, USA) supplemented with 5% FBS and 1 mg/mL G418 (Nacalai, Kyoto, Japan). The cells were grown at 37°C in a CO2 incubator. Virus SARS-CoV-2 viral strain JPN/TY/WK/521 was provided by the National Institute of Infectious Diseases, Tokyo, Japan. Viruses were propagated in monolayers of VeroE6/TMPRSS2 cells in DMEM supplemented with 2% FBS and 1 mg/mL G418 at a multiplicity of infection of 0.01. Virus titration Infectivity was titrated by a focus-forming assay as described previously (Yasugi et al. 2013 ) with slight modifications. Viruses were serially diluted 10-fold in DMEM supplemented with 2% FBS and infected with confluent VeroE6 cells for 8 h. The cells were fixed with 4% paraformaldehyde for 15 min and washed with phosphate-buffered saline (PBS) three times. After the cells were permeabilized with 0.1% Triton ® X-100 for 15 min and washed with PBS three times, they were incubated with rabbit anti-nucleocapsid monoclonal antibody (Thermo Fisher Scientific) at a..
References
Kanda, Investigation of the freely available easy-to-use software 'EZR' for medical statistics, Bone Marrow Transplant
Komatsu, Ikeda, Tanaka, Matsuzaki, Development of practical artificial intelligence system for drug discovery and its application to activity prediction of small molecule protein-protein interaction modulators, J Biol Macromol
Komatsu, Tanaka, Matsuzaki, Efficient drug discovery approach for PPI and ubiquitin-proteasome targets with unique in silico screening and AI-based activity prediction technologies, Medical Science Digest
Komatsu, Tanaka, Ye, Ikeda, Matsuzaki et al., Identification of SARS-CoV-2 main protease inhibitors from FDA-approved drugs by artificial intelligence-supported activity prediction system, J Biomol Struct Dyn
Matsuyama, Nao, Shirato, Kawase, Saito et al., Enhanced isolation of SARS-CoV-2 by TMPRSS2-expressing cells, Proc Natl Acad Sci
Sato, Kashiwakura, Yamaguchi, Yoshino, Tanaka et al., Discovery of a novel small-molecule interleukin-6 inhibitor through virtual screening using artificial intelligence, Med Chem
Yasugi, Kubota-Koketsu, Yamashita, Kawashita, Du et al., Human monoclonal antibodies broadly neutralizing against influenza B virus, PLoS Pathog,
doi:10.1371/journal.ppat.1003150
