Terpenoids such as geraniol and citral are known to have antibacterial, antifungal and anti-cancerous properties; however, their mechanism of action is least understood. In this study, the antifungal mechanism of monoterpene alcohol (geraniol) and monoterpene aldehyde (citral) was studied using Saccharomyces cerevisiae throughout 120 h duration and over a maximum tolerable dosage of 0.5% (v/v). Cell growth studies using optical density readings at 600 nm (OD λ=600 nm), Cell viability using MTT assay, Na + /K + leakage into media, osmotic stress using flame photometry, detection of metabolites like dehydroergosterol (DHE), H 2 O 2 using fluorescence spectroscopy, changes in functional group analysis using FT-IR, elemental analysis using EDAX, DNA damage using gel electrophoresis and cellular structural changes using SEM were carried out. Growth inhibition studies using OD λ=600 nm and MTT assays suggest that both geraniol and citral inhibited the growth kinetics significantly up to 0.1% v/v at and significantly increased beyond 0.1% at all the studied time points. Both the monoterpenoids induced the osmotic stress in S. cerevisiae measured as a change in reduction in pH, [H] + concentration, with elevation in [Na] + and [K] + leakage into the media. Geraniol treatment reduced the levels of metabolites, dehydroergosterol (DHE) and H 2 O 2 , in a time-dependent manner whereas citral only affected their levels at 120 h. Energy dispersive X ˗ ray spectroscopy (EDAX) studies suggest that both the monoterpenoids treatment differentially modulated the cellular elemental contents. Geraniol (0.03% v/v) and not the citral treatment induced DNA damage. Cellular structural analysis showed that both monoterpenoids have differential damaging effects to S. cerevisiae. This study shows that having an aldehyde and alcohol group on the terpenoids strongly affect the anti-fungal activity.

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<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^-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.</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:roopag81@yahoo.com">roopag81@yahoo.com</a></p>

<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^-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.</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:roopag81@yahoo.com">roopag81@yahoo.com</a></p>