<p><b>To</b></p>
<p><b>Respected
Sir/Madam</b> </p>
<p>Chemarxiv</p>
<p> </p>
<p><b>Respected
Sir/Madam</b> </p>
<p> </p>
<p><b>Sub</b>: submission of preprint of article to Chemarxiv for online
publication.</p>
<p> </p>
<p>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”.</p>
<p> </p>
<p>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<sup>-1</sup> while for hydroxychloroquine it is -6.66 kcal mol<sup>-1</sup>.
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.</p>
<p>I hope that the manuscript will full fill the
journal’s requirements and will get accepted for publication. </p>
<p>Thanking you</p>
<p> </p>
<p>With regards</p>
<p>Roopa Guthappa</p>
<p><a href="mailto:[email protected]">[email protected]</a></p>