Synthesis of Aminophenoxazinones and Evaluation of Their Phytotoxicity in the Search for New Natural Herbicides

Round 1

Reviewer 1 Report

The manuscript entitled "Synthesis of aminophenoxazinones and evaluation of their phytotoxicity in the search for new natural herbicides" describes the synthesis and the characterization of a small library of aminophenoxazinones as possible new agrochemicals. The topic is very interesting, the paper is well written and all the data are well presented. There is a complete description of the possible biological action of the library compare to well known molecules. There are some typos (see the file attached) and some compounds need to be fully characterized: in some case the high resolution mass and the IR spectra are missing. My overall suggestion is to accept the manuscript with minor revisions

Comments for author File: Comments.pdf

Author Response

Thank you so much for all your comments. Following your suggestions, we have added the exact mass of the missing compounds obtained that are not previously reported by High Resolution Mass Spectrometry. We have corrected the mistypes you found for us.

Reviewer 2 Report

The manuscript title “Synthesis of aminophenoxazinones and evaluation of their phytotoxicity in the search for new natural herbicides” has scientific worth but required some minor improvements. My comments for authors are as follows:

Reviewer Comments:

1-      In abstract; Line 15: please modify the sentence such as “In this study, ……..”.

2-      Whenever use any abbreviation than explain its full name, first time. Line 97, 100, 104: UPLC-QTOF-ESI?? VWR? Provide full name of all abbreviations used in the MS.

3-      I suggest authors to add a separate conclusion section in the manuscript and highlight your key findings and give some future prospective.

Author Response

• ‘The manuscript title “Synthesis of aminophenoxazinones and evaluation of their phytotoxicity in the search for new natural herbicides” has scientific worth but required some minor improvements. My comments for authors are as follows’

Authors really appreciate your comments and suggestions.

• In abstract; Line 15: please modify the sentence such as “In this study, ……..”.

Done

• Whenever use any abbreviation than explain its full name, first time. Line 97, 100, 104: UPLC-QTOF-ESI?? VWR? Provide full name of all abbreviations used in the MS.

Abbreviations have been defined. VWR is a chemical company that supply us reagents and solvents.

• I suggest authors to add a separate conclusion section in the manuscript and highlight your key findings and give some future prospective.

As suggested conclusion section was added to the MS highlighting the most important findings and the future prospectives.

Reviewer 3 Report

Dear authors, please find my commnets in attached pdf. Regards

Comments for author File: Comments.pdf

Author Response

Thank you for all your comments, the changes are as follows:

• Line 28-29: Refering to Ref. 1 and 2. Data reported here are not Scavo et al or Jabran et al data. The prediction of yiled losses caused by weeds has been estimated by Oerke E, 2006. Please check it once again and correct.

References are updated.

• Line 252: ADD SPACE

Added.

• Line 281: Figure 2. This part belongs rathers to section Matherial and methods than to Results.

We have changed the place of the figure and moved to the section of Materials and methods in line 108. We also have added a section explaining briefly what the synthesis consists of.

• Line 420: Please discuss here what does it mean for production if phytotoxic activity has been demonstrated on wheat. For further investigation and development of natural compounds phytotoxicity to wheat could present a problem for selective herbicide application.

When evaluating the phytotoxic activity of compounds, it is necessary to have an evaluation tool that is sensitive, simple, fast and uses small amounts of sample. In this sense, the etiolated wheat coleoptile bioassay is used. This bioassay is not a seed bioassay. In this case, the coleoptile is used from wheat because it is a robust coleoptile that allows its manipulation. Coleoptiles have undifferentiated meristematic plant cells that serve as a highly sensitive plant cellular model to evaluate the effect that extracts, fractions or products have on them. These results can be observed macroscopically in stimulation or inhibition on the growth of coleoptile with respect to control. If inhibition occurs, the fraction or the product evaluated has phytotoxic activity. If there is no inhibition, this sample is not selected for further tests or studies since it lacks activity. It is the first step when evaluating the phytotoxic potential since if we evaluate on a specific seed we could only know if it is phytotoxic on that particular seed. Therefore, in the first stage, we need to have an evaluation tool with a wide scope such as coleoptile bioassay

Reviewer 4 Report

Interesting study. However, the results relating to phytotoxic activity should be more precise. Portulaca was more susceptible than Lolium. Also, roots were more susceptible than shoots. Still, this information is not present in the abstract or conclusions. That must be corrected.

Some minor comments:

Delete the keywords that are the same as in the title. Add more specific keywords.

Figure 1 Title, DIMBOA to AMPO

ln. 85 "benzoxa of action" wat does this expression mean?

Table 1, abbreviation in table should be AI for pendimethalin, not "PA"

Ln. 334 apart from compounds 3, 5, 7.

Author Response

• ‘Interesting study. However, the results relating to phytotoxic activity should be more precise. Portulaca was more susceptible than Lolium. Also, roots were more susceptible than shoots. Still, this information is not present in the abstract or conclusions. That must be corrected.’

Thank you so much for your observations and comments. We have added in abstract and conclusion sections the suggestions indicated.

Some minor comments:

• Delete the keywords that are the same as in the title. Add more specific keywords.

We have deleted the keywords ‘Phytotoxic’ and ‘Aminophenozaxinones’ and added keywords that complete the title.

• Figure 1 Title, DIMBOA to AMPO

Done.

• Line 85 "benzoxa of action" wat does this expression mean?

It was a mistake. We have already changed it for ‘mode of action’.

• Table 1, abbreviation in table should be AI for pendimethalin, not "PA"

Done.

• Line. 334 apart from compounds 3, 5, 7.

Even the compounds 3 and 7 have lower inhibitory activity than the other compounds, the activity of these compounds at the highest concentration is near or even higher than -40%. For these reasons we only excluded compound 5.