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covid final submittted 20-4-2020.docx (821.5 kB)

Molecular Docking Studies of N-Acetyl Cysteine, Zinc Acetyl Cysteine and Niclosamide on SARS Cov 2 Protease and Its Comparison with Hydroxychloroquine

submitted on 21.04.2020, 06:03 and posted on 22.04.2020, 12:17 by Roopa Guthappa


Respected Sir/Madam


Respected Sir/Madam

Sub: submission of preprint of article to Chemarxiv for online publication.

I am herewith submitting the preprint of an article entitled “Molecular docking studies of N-acetyl cysteine, zinc acetyl cysteine and niclosamide on SARS Cov 2 protease and its comparison with hydroxychloroquine” for possible publication in “Chemarxiv”.

In this article, we have evaluated the binding abilities of N-acetyl cysteine, zinc acetyl cysteine and niclosamide (antiviral drug) with SARS-COV-2 protease. All the four compounds investigated are effective and selectively bind to active sites of main protease. N-acetyl cysteine being a derivative of cysteine interacts with Cys-145, His-163, Gly-143 of COV-2 protease, zinc acetyl cysteine binds to Gly-143, Ser-144, Cys-145, Glu-166 of COV-2 protease and niclosamide bind to Glu-166, Cys-145, His 41 of main protease. The data has been compared with hydroxychloroquine which effectively binds to Cys-145, Glu-166, Arg-188. The binding affinities of N-acetyl cysteine, zinc-acetyl cysteine and niclosamide are -4.24, -4.29 and -7.5 kcal mol-1 while for hydroxychloroquine it is -6.66 kcal mol-1. Niclosamide with its lowest binding energy interacts with His-41 and Cys-145 which may be the first molecule to show such binding interaction. The results indicate that N-acetyl cysteine, zinc-acetyl cysteine and niclosamide can also be explored for the treatment for SARS COV-2 as an alternative for hydroxychloroquine.

I hope that the manuscript will full fill the journal’s requirements and will get accepted for publication.

Thanking you

With regards

Roopa Guthappa


Email Address of Submitting Author


Independent Researcher, Gayathrinagar



ORCID For Submitting Author

Declaration of Conflict of Interest

no conflict of interest


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