Chiral Pyrazolo[4,3-e][1,2,4]triazine Sulfonamides—Their Biological Activity, Lipophilicity, Protein Affinity, and Metabolic Transformations

Round 1

Reviewer 1 Report

The article describes the analysis of pyrazolo[4,3-e][1,2,4]triazine sulfonamides through in silico mechanism  at molecular level by molecular docking method. The article is original and interesting however a few quiestion marks should be answered before publication.

The abstract should rewritten partially as the authors make suggestion about their previous work regarding the topic. The abstract should be restricted to describe the findings of the current article.

A more throughout presentation of the compounds should be introduced in the Introduction section.

The iconography is very good, congratulation to the authors. 

Possible pharmacological use can be speculated, what can be be the use in therapy of the compounds ?

All presented sulfonamides were obtained using multistep procedure and occurred to be inactive against cancer cell lines. Also the compounds were characterized by a small affinity for plasma proteins which could be advantageous in further potential in vivo studies. Their lipophilicity may be connected with large polarity of molecules confirmed by large values of dipole moments theoretically calculated for investigated sulfonamides using DFT method.
The investigated pyrazolotriazines were sensitive to metabolic transformations with phase I enzymes, what led to the hydroxylation and dealkylation products, whereas phase II transformations were not observed, maybe it can be speculated that the proposed I phase metabolites would be
responsible for the deactivation of studied compounds. What about the perspectives of the compounds ?

There are a few grammar errors in the manuscript, which should be corrected before publication.

Author Response

Answers to reviewers' comments

On behalf of the authors, thank you very much for your review of our manuscript.

Rev. 1

1. The abstract should rewritten partially as the authors make suggestion about their previous work regarding the topic. The abstract should be restricted to describe the findings of the current article.

The abstract and the introduction have been modified.

2. Possible pharmacological use can be speculated, what can be be the use in therapy of the compounds ?

So far, this group of compounds has been studied as inhibitors of enzymes (PDE5, urease and tyrosinase) and their anticancer potential. Due to the various properties of sulfonamides, in further studies we will check their bactericidal and fungicidal properties.

3. All presented sulfonamides were obtained using multistep procedure and occurred to be inactive against cancer cell lines. Also the compounds were characterized by a small affinity for plasma proteins which could be advantageous in further potential in vivo studies. Their lipophilicity may be connected with large polarity of molecules confirmed by large values of dipole moments theoretically calculated for investigated sulfonamides using DFT method.
   The investigated pyrazolotriazines were sensitive to metabolic transformations with phase I enzymes, what led to the hydroxylation and dealkylation products, whereas phase II transformations were not observed, maybe it can be speculated that the proposed I phase metabolites would be responsible for the deactivation of studied compounds. What about the perspectives of the compounds ?

Research on this group of compounds is continued and includes their further structural modifications and the search for new directions of biological activity.

4. There are a few grammar errors in the manuscript, which should be corrected before publication.

The errors in the text have been corrected.

Reviewer 2 Report

The manuscript presents an interesting work.

However, it needs minor revision to become acceptable for publication.

In 4.5 Molecular docking

• there is complenmentarity but the correct form is complementarity;
• in PBD:2Y9X there is a LECTIN-LIKE FOLD PROTEIN in complex with the tyrosinase. Do you consider this protein in the docking?

Please check the manuscript, because there are some repeated words. For example in in…

Author Response

Answers to reviewers' comments

On behalf of the authors, thank you very much for your review of our manuscript.

Rev. 2

The manuscript presents an interesting work.

However, it needs minor revision to become acceptable for publication.

1. In 4.5 Molecular docking

• there is complenmentarity but the correct form is complementarity;

It has been corrected.

• in PBD:2Y9X there is a LECTIN-LIKE FOLD PROTEIN in complex with the tyrosinase. Do you consider this protein in the docking?

However, the presence of the lecithin-like fold protein has practically no effect on the docking result due to the distance of amino acid residues of this protein greater than 6 Å (about 25 Å; [29] W. T. Ismaya, H. J. Rozeboom, A. Weijn, J. J. Mes, F. Fusetti, H. J. Wichers, B. W. Dijkstra, Biochemistry 2011, 50, 5477-5486) from the active site of the enzyme occupied by tropolone inhibitor."

Please check the manuscript, because there are some repeated words. For example in in…

The text has been checked and corrected.