and nonlinear optical response properties: A quantum chemical approach. *J. Mol. Graph. Model.* 102, 107766. doi:10.1016/j.jmgm.2020.107766

Muthu, S., Ramachandran, G., Paulraj, R. I., and Swaminathan, T. (2014). Quantum mechanical study of the structure and spectroscopic (FTIR, FT-Raman), first-order hyperpolarizability and NBO analysis of 1, 2-benzoxazol-3-ylmethane sulfonamide. *Spectrochim. Acta Part A Mol. Biomol. Spectrosc.* 128, 603–613. doi:10.1016/j.saa.2014.02.183

Omrani, A. S., Saad, M. M., Baig, K., Bahloul, A., Abdul-Matin, M., Alaidaroos, A. Y., et al. (2014). Ribavirin and interferon alfa-2a for severe Middle East respiratory syndrome coronavirus infection: A retrospective cohort study. *Lancet Infect. Dis.* 14, 1090–1095. doi:10.1016/s1473-3099(14)70920-x

Parrinello, M., and Rahman, A. (1981). Polymorphic transitions in single crystals: A new molecular dynamics method. *J. Appl. Phys.* 52, 7182–7190. doi:10.1063/1.328693

Pearson, R. G. (1986). Absolute electronegativity and hardness correlated with molecular orbital theory. *Proc. Natl. Acad. Sci. U. S. A.* 83, 8440–8441. doi:10.1073/pnas.83.22.8440

Pearson, R. G. (1990). Hard and soft acids and bases—the evolution of a chemical concept. *Coord. Chem. Rev.* 100, 403–425. doi:10.1016/0010-8545(90)85016-1

Phillips, J. C. (1961). Generalized koopmans' theorem. *Phys. Rev.* 123, 420–424. doi:10.1103/PhysRev.123.420

Pillaiyar, T., Manickam, M., Namasivayam, V., Hayashi, Y., and Jung, S. H. (2016). An overview of severe acute respiratory syndrome-coronavirus (SARS-CoV) 3CL protease inhibitors: Peptidomimetics and small molecule chemotherapy. *J. Med. Chem.* 59, 6595–6628. doi:10.1021/acs.jmedchem.5b01461

Ruan, Z., Liu, C., Guo, Y., He, Z., Huang, X., Jia, X., et al. (2020). SARS-CoV-2 and SARS-CoV: Virtual screening of potential inhibitors targeting RNA-dependent RNA polymerase activity (NSP12). *J. Med. Virol.* 93, 389–400. doi:10.1002/jmv.26222

Salvatore, M. J., King, A. B., Graham, A. C., Onishi, H. R., Bartizal, K. F., Abruzzo, G. K., et al. (1998). Antibacterial activity of lonchocarpol A. *J. Nat. Prod.* (Gorakhpur). 61 (5), 640–642. doi:10.1021/np9703961

Sastry, G. M., Adzhigirey, M., Day, T., Annabhimoju, R., and Sherman, W. (2013). Protein and ligand preparation: Parameters, protocols, and influence on virtual screening enrichments. *J. Comput. Aided. Mol. Des.* 27, 221–234. doi:10.1007/s10822-013-9644-8

Schrödinger (2018). *Schrödinger release 201 8-4: Maestro schrödinger*. New York, NY: LLC.

Schrödinger (2020). *Schrödinger release 2020-2: Prime, schrödinger*. New York, NY: LLC.

Seah, I., and Agrawal, R. (2020). Can the coronavirus disease 2019 (COVID-19) affect the eyes? A review of coronaviruses and ocular implications in humans and animals. *Ocul. Immunol. Inflamm.* 28, 391–395. doi:10.1080/09273948.2020.1738501

Stewart, J. J. P. (1990). MOPAC: A semiempirical molecular orbital program. *J. Comput. Aided. Mol. Des.* 4, 1–103. doi:10.1007/BF00128336

Sylaja, B., Gunasekaran, S., and Srinivasan, S. (2017). Vibrational, NLO, NBO, NMR, frontier molecular orbital and molecular docking studies of diazepam. *Mater. Res. Innovations* 22, 1–13. doi:10.1080/14328917.2017.1324356

Tripathi, S. K., Muttineni, R., and Singh, S. K. (2013). Extra precision docking, free energy calculation and molecular dynamics simulation studies of CDK2 inhibitors. *J. Theor. Biol.* 334, 87–100. doi:10.1016/j.jtbi.2013.05.014

Vellingiri, B., Jayaramayya, K., Iyer, M., Narayanasamy, A., Govindasamy, V., Giridharan, B., et al. (2020). COVID-19: A promising cure for the global panic. *Sci. Total Environ.* 725, 138277. doi:10.1016/j.scitotenv.2020.138277

Wang, S. Q., Du, Q. S., Zhao, K., Li, A. X., Wei, D. Q., and Chou, K. C. (2007). Virtual screening for finding natural inhibitor against cathepsin-L for SARS therapy. *Amino Acids* 33 (1), 129–135. doi:10.1007/s00726-006-0403-1

World Health Organization (2004). SARS: Clinical trials on treatment using a combination of traditional Chinese medicine and western medicine. Beijing: World Health Organization.

Wu, C. Y., Jan, J. T., Ma, S. H., Kuo, C. J., Juan, H. F., Cheng, Y. S. E., et al. (2004). Small molecules targeting severe acute respiratory syndrome human coronavirus. *Proc. Natl. Acad. Sci. U. S. A.* 101 (27), 10012–10017. doi:10.1073/pnas.0403596101

Xu, C., Ke, Z., Liu, C., Wang, Z., Liu, D., Zhang, L., et al. (2020). Systemic *in silico* screening in drug discovery for Coronavirus Disease (COVID-19) with an online interactive web server. *J. Chem. Inf. Model.* 60, 5735–5745. doi:10.1021/acs.jcim.0c00821

Yu, M.-S., Lee, J., Lee, J. M., Kim, Y., Chin, Y.-W., Jee, J.-G., et al. (2012). Identification of myricetin and scutellarein as novel chemical inhibitors of the SARS coronavirus helicase, NSP13. *Bioorg. Med. Chem. Lett.* 22 (12), 4049–4054. doi:10.1016/j.bmcl.2012.04.081

Zumla, A., Chan, J. F., Azhar, E. I., Hui, D. S., and Yuen, K. Y. (2016). Corona viruses-drug discovery and therapeutic options. *Nat. Rev. Drug Discov.* 15, 327–347. doi:10.1038/nrd.2015.37
and nonlinear optical response properties: A quantum chemical approach. *J. Mol. Graph. Model.* 102, 107766. doi:10.1016/j.jmgm.2020.107766

Muthu, S., Ramachandran, G., Paulraj, R. I., and Swaminathan, T. (2014). Quantum mechanical study of the structure and spectroscopic (FTIR, FT-Raman), first-order hyperpolarizability and NBO analysis of 1, 2-benzoxazol-3-ylmethane sulfonamide. *Spectrochim. Acta Part A Mol. Biomol. Spectrosc.* 128, 603–613. doi:10.1016/j.saa.2014.02.183

Omrani, A. S., Saad, M. M., Baig, K., Bahloul, A., Abdul-Matin, M., Alaidaroos, A. Y., et al. (2014). Ribavirin and interferon alfa-2a for severe Middle East respiratory syndrome coronavirus infection: A retrospective cohort study. *Lancet Infect. Dis.* 14, 1090–1095. doi:10.1016/s1473-3099(14)70920-x

Parrinello, M., and Rahman, A. (1981). Polymorphic transitions in single crystals: A new molecular dynamics method. *J. Appl. Phys.* 52, 7182–7190. doi:10.1063/1.328693

Pearson, R. G. (1986). Absolute electronegativity and hardness correlated with molecular orbital theory. *Proc. Natl. Acad. Sci. U. S. A.* 83, 8440–8441. doi:10.1073/pnas.83.22.8440

Pearson, R. G. (1990). Hard and soft acids and bases—the evolution of a chemical concept. *Coord. Chem. Rev.* 100, 403–425. doi:10.1016/0010-8545(90)85016-1

Phillips, J. C. (1961). Generalized koopmans' theorem. *Phys. Rev.* 123, 420–424. doi:10.1103/PhysRev.123.420

Pillaiyar, T., Manickam, M., Namasivayam, V., Hayashi, Y., and Jung, S. H. (2016). An overview of severe acute respiratory syndrome-coronavirus (SARS-CoV) 3CL protease inhibitors: Peptidomimetics and small molecule chemotherapy. *J. Med. Chem.* 59, 6595–6628. doi:10.1021/acs.jmedchem.5b01461

Ruan, Z., Liu, C., Guo, Y., He, Z., Huang, X., Jia, X., et al. (2020). SARS-CoV-2 and SARS-CoV: Virtual screening of potential inhibitors targeting RNA-dependent RNA polymerase activity (NSP12). *J. Med. Virol.* 93, 389–400. doi:10.1002/jmv.26222

Salvatore, M. J., King, A. B., Graham, A. C., Onishi, H. R., Bartizal, K. F., Abruzzo, G. K., et al. (1998). Antibacterial activity of lonchocarpol A. *J. Nat. Prod.* (Gorakhpur). 61 (5), 640–642. doi:10.1021/np9703961

Sastry, G. M., Adzhigirey, M., Day, T., Annabhimoju, R., and Sherman, W. (2013). Protein and ligand preparation: Parameters, protocols, and influence on virtual screening enrichments. *J. Comput. Aided. Mol. Des.* 27, 221–234. doi:10.1007/s10822-013-9644-8

Schrödinger (2018). *Schrödinger release 201 8-4: Maestro schrödinger*. New York, NY: LLC.

Schrödinger (2020). *Schrödinger release 2020-2: Prime, schrödinger*. New York, NY: LLC.

Seah, I., and Agrawal, R. (2020). Can the coronavirus disease 2019 (COVID-19) affect the eyes? A review of coronaviruses and ocular implications in humans and animals. *Ocul. Immunol. Inflamm.* 28, 391–395. doi:10.1080/09273948.2020.1738501

Stewart, J. J. P. (1990). MOPAC: A semiempirical molecular orbital program. *J. Comput. Aided. Mol. Des.* 4, 1–103. doi:10.1007/BF00128336

Sylaja, B., Gunasekaran, S., and Srinivasan, S. (2017). Vibrational, NLO, NBO, NMR, frontier molecular orbital and molecular docking studies of diazepam. *Mater. Res. Innovations* 22, 1–13. doi:10.1080/14328917.2017.1324356

Tripathi, S. K., Muttineni, R., and Singh, S. K. (2013). Extra precision docking, free energy calculation and molecular dynamics simulation studies of CDK2 inhibitors. *J. Theor. Biol.* 334, 87–100. doi:10.1016/j.jtbi.2013.05.014

Vellingiri, B., Jayaramayya, K., Iyer, M., Narayanasamy, A., Govindasamy, V., Giridharan, B., et al. (2020). COVID-19: A promising cure for the global panic. *Sci. Total Environ.* 725, 138277. doi:10.1016/j.scitotenv.2020.138277

Wang, S. Q., Du, Q. S., Zhao, K., Li, A. X., Wei, D. Q., and Chou, K. C. (2007). Virtual screening for finding natural inhibitor against cathepsin-L for SARS therapy. *Amino Acids* 33 (1), 129–135. doi:10.1007/s00726-006-0403-1

World Health Organization (2004). SARS: Clinical trials on treatment using a combination of traditional Chinese medicine and western medicine. Beijing: World Health Organization.

Wu, C. Y., Jan, J. T., Ma, S. H., Kuo, C. J., Juan, H. F., Cheng, Y. S. E., et al. (2004). Small molecules targeting severe acute respiratory syndrome human coronavirus. *Proc. Natl. Acad. Sci. U. S. A.* 101 (27), 10012–10017. doi:10.1073/pnas.0403596101

Xu, C., Ke, Z., Liu, C., Wang, Z., Liu, D., Zhang, L., et al. (2020). Systemic *in silico* screening in drug discovery for Coronavirus Disease (COVID-19) with an online interactive web server. *J. Chem. Inf. Model.* 60, 5735–5745. doi:10.1021/acs.jcim.0c00821

Yu, M.-S., Lee, J., Lee, J. M., Kim, Y., Chin, Y.-W., Jee, J.-G., et al. (2012). Identification of myricetin and scutellarein as novel chemical inhibitors of the SARS coronavirus helicase, NSP13. *Bioorg. Med. Chem. Lett.* 22 (12), 4049–4054. doi:10.1016/j.bmcl.2012.04.081

Zumla, A., Chan, J. F., Azhar, E. I., Hui, D. S., and Yuen, K. Y. (2016). Corona viruses-drug discovery and therapeutic options. *Nat. Rev. Drug Discov.* 15, 327–347. doi:10.1038/nrd.2015.37