Chemotypes of Species of the Genus Thymus L. in Carpathians Region of Ukraine—Their Essential Oil Qualitative and Quantitative Characteristics and Antimicrobial Activity

Round 1

Reviewer 1 Report

This work describes the extraction of essential oils from species of the genus Thymus L. The composition of obtained oils was analyzed and their antimicrobial activity was evaluated.

The authors presented an interesting study with some interesting results. The current work could be considered for publication after considering the following comments:

 

1. In the introduction part: delete lines 35-43.

2. Page 5 L163: what do you mean by "..using a mixture of hexane to collect the solvent". Using hexane, or a mixture of hexane with other solvent. Please check. Which solvent? hydrodistillation means water as solvent.

3. Check references: Page 7 L 244; Page 13 L 395;

4. Check numbering in the conclusion

Author Response

Dear reviewer, thank you for your comments. We have tried correct all your comments.

Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript needs to be improved before it can be accepted. My comments are listed below:

-Introduction: it is not well organized, I suggest the authors to delete irrelevant texts and introduce the background in a logical way. Other details include:

L35-43 seems to be part of the author guides, they should be deleted from the text.-L56: “t was found…”?

-Results:

Table1: “GC profil (%)” it should be profile?

Table 3 & 4: needs to explain what are the data in the table.

-Discussion:

L395: “Tymchenko I.A. et al., 2007” only include the first author’s surname.

Figure 2 &3 are results, should be moved to the results section, not the discussion section.

-Conclusions: it should be summarized into one paragraph.

L543：it should be 3 instead of 2

Author Response

Dear reviewer, tank you for your comments. We tried to correct all.

Author Response File: Author Response.docx

Reviewer 3 Report

1. I advice to short the conclusions and underline only the most important;

2. Please describe more precisely the distillations details (mass of plant used, flask volume, apparatus type etc.);

3.  Vorrect "linalol";

4. Provide bellow Table 1 the percentage of totally identified compounds;

5. If possible, provide values of retention indices to the Table compounds;

6. Which isomer of thyuon was identified?;

7. Correct typo in  "β-caryophylene"

8. What is a value for trace ( I mean below 0,05% or something like that)?

9. Change commas to dots in all Tables;

10. Correct typo in "α- terpinen";

11. Are there any information about voucher specimen deposited in local herbarium?

12. Correct typo in "bornylacetate";

13. Which isomer of cineole you meant? 1,8 I guess?

14. Add info, why polar column was chosen;

15. The components were identified according to their retention 175 time, and the got values were compared with literature data;

16. The components were identified according to their retention  time, and the got values were compared with literature data. Please precise which data? Perhaps retention indices?

 

 

 

Author Response

Dear reviewer, thank you for your comments. We tried to correct all,

Author Response File: Author Response.docx

Reviewer 4 Report

Dear Editor(S) and authors, 

The manuscript (Chemotypes of species of the genus Thymus L. in Carpathians region of Ukraine – their essential oil qualitative and quantitative characteristics and antimicrobial activity) needs many corrects and modifications.

1-At the end of the manuscript abstract , the main conclusion should be added clearly.

2-The introduction needs to add some modern references in several places, see line 72-73. I suggest to  read and add some references such as (Vargas-Sánchez, R. D., Ibarra-Arias, F. J., del Mar Torres-Martínez, B., Sánchez-Escalante, A., & Torrescano-Urrutia, G. R. (2019). Use of natural ingredients in Japanese quail diet and their effect on carcass and meat quality—A review. Asian-Australasian Journal of Animal Sciences, 32(11), 1641.,

‏Najar, B., Pistelli, L., Ferri, B., Angelini, L. G., & Tavarini, S. (2021). Crop Yield and Essential Oil Composition of Two Thymus vulgaris Chemotypes along Three Years of Organic Cultivation in a Hilly Area of Central Italy. Molecules, 26(16), 5109.‏

3-The aim of manuscript is weak and unclear, please rewrite again.

4-Many work methods without adding scientific references,  see  Essential Oil (EO) distillation of the Thymus spesies Samples and Analyses of the Essential Oils , and this reduces the value of scientific research. I suggest adding 

1-Al-fekaiki, D. F., Niamah, A. K., & Al-Sahlany, S. T. G. (2017). Extraction and identification of essential oil from Cinnamomum zeylanicum barks and study the antibacterial activity. Journal of microbiology, biotechnology and food sciences, 2017, 312-316.

2-Hao, R., Roy, K., Pan, J., Shah, B. R., & Mraz, J. (2021). Critical review on the use of essential oils against spoilage in chilled stored fish: A quantitative meta-analyses. Trends in Food Science & Technology, 111, 175-190.

5-  The method of Antimicrobial Activity is unclear and there are many questions about it . How many bacteria numbers are in 0.5 McFarland standard?, Have you left the dishes for a period of time in the refrigerator?, How did you incubate the dishes in the incubator? This method needs to add reference  (Al-Sahlany, S. T. G. (2016). Effect of Mentha piperita essential oil against Vibrio spp. isolated from local cheeses. Pak. J. Food Sci, 26(2), 65-71.‏).

6-Table 3 and table 4 The tested microorganisms numbered 5 in working methods See page 6 lines 184-186, why in the table there were 4?  When the result of Enterococcus faecalis?

7-Figure 3, The tested microorganisms numbered 5 in working methods See page 6 lines 184-186, why in the table there were 4?  When the result of Enterococcus faecalis?

8-Table 1 and Table2 need to add the percentage of top area and retention time so that the reader can know the concentration of the apparent compounds, these tables are not clear and ambiguous.

9-Figures 2 and 3 need to add statistical analysis.

10-The conclusions in the manuscript need to be rewritten again, it contains many results and this is not permissible in academic writing, the conclusion must be clear and not a result.

‏11-Linguistically, the manuscript needs to be reviewed by specialists because it contains some errors in the grammar.

Author Response

Dear reviewer! Thank you for your comments, we tried to correct all.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

In table 3 and table 4, indicate what are those numbers? for example, are they the diameter of the inhibition zone? 

Author Response

thank you for your comments

Author Response File: Author Response.doc

Reviewer 3 Report

Authors did some improvements. 

Please correct also:

a) "cis-r-ment-2- en-1-ol" (it should be "cis-p-ment-2- en-1-ol);

b) what is "lambda terpinene (L. 93)? Perhaps gamma? 

c) diisooctyl ether of phthalic acid is an artefact (plasticiser). Please remove it from manuscript. Even, if was "found" by authors;

d) what is % hm?

e) above 32# of EOs components (sample 1.3, as well as a 2.1.Table 1 were not identified).  It is a huge number. Especially, when you identify some components as trace (0.2%). Please re-check,  what was missed?

f) European Pharmacopoeia methods (Eu. Pharm. 8, 2018) did not write about this  column, which was used. Please re-check it or write about equipment availability, your previous experiences etc.

 

Author Response

thank you for your comments

Author Response File: Author Response.doc

Reviewer 4 Report

Dear editor (s), 

The authors made all the necessary adjustments to the manuscript to make it better, and I now propose that it be published as is.

Author Response

thank you for your comments

Author Response File: Author Response.doc