Zanthoxylum bungeanum Essential Oil: Extraction and Component Analysis for α-Glucosidase Inhibitory Activity and the Underlying Mechanism Based on Molecular Docking
Round 1
Reviewer 1 Report
This manuscript researched extraction, main compounds, alpha-glucosidase inhibitory activity, and its mechanism of the Zanthoxylum bungeanum essential oil. The authors' findings are thought to be of some use to the Zanthoxylum bungeanum essential oil. However, I think it will be a better paper if the authors are revised following the attachment file.
Revision points;
1. Abstract
- Line 13: 21 species changed to 20 species. In the materials and methods and results presented, it was found that 19 species of essential oil were used to compare the alpha-glucosidase inhibitory activity with that of Zanthoxylum bungeanum essential oil.
- Line 22: Those are close to the binding energy between anthocyanins…. Did the authors use anthocyanins to evaluate in comparison with the essential oil of Zanthoxylum bungeanum?
2. Introduction
- Line 33 and 49: move the citation to the end of the sentence.
- Line 42-43: e. The aroma of Zanthoxylum bungeanum fruit is because it contains a lot of essential oil. Please explain what kind of essential oil.
3. Materials and Methods
- Did the authors know the extraction method used for extracting the essential oil from other species? If a different method was used, how does it compare in terms of alpha-glucosidase inhibitory activity to the extraction method used for Zanthoxylum bungeanum?
- Line 68: delete “in Table3”
- The unshielded particles and sieved powder were sampled in the ratio of 1:2. This sentence is not clear; please revise it.
- Section 2.3: Please specify the time for sample collection (Line 81) and the temperature of the distillation method (Line 85). In addition, please separate the steam distillation and eutectic solvent procedures.
- Line 86: Please use an article instead of the number.
- After adding sodium carbonate solution(1.0 mol/L)100 μL the reaction was terminated, and the absorbance of the test solution was measured at 405 nm. Please revise it.
4. Results and Discussion
- It is necessary to explain what kind of extraction method is best to extract essential oil from Zanthoxylum bungeanum.
- Figure 1, please provide more detail for the figure legend.
- It is reported that although 26 varieties of Zanthoxylum pericarp extracts and main Inhibitory Ingredients against α-glucosidase were measured13, the inhibitory on α-glucosidase activities of different species of plant essential oils were compared in this paper. This sentence is not clear; please revise it.
- In Figure 2, can the authors provide the name of the arrow and the compounds?
- It will be better to provide all the compounds found in Zanthoxylum bungeanum essential oil.
- Please provide a discussion regarding the absence of limonene and linalool in the essential oil of Zanthoxylum bungeanum.
- It would be better to provide the molecular docking scores or binding affinities (kcal/mol) of the main compounds in a table form.
- The conclusion of this work should be revised to cover all experiments.
Author Response
Dear Editors and Reviewers:
Thank you for your letter and for the reviewers" comments concerning our
manuscript entitled ‘Zanthoxylum bungeanum Essential Oil: Extraction, Component Analysis, against α-Glucosidase Activity and Mechanism’ (applsci-2215924). Those comments are all valuable and very helpful for revising and improving our paper. We have studied comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and the responds to the reviewer's comments are as flowing:
Revision points;
- Line 13: 21 species changed to 20 species. In the materials and methods and results presented, it was found that 19 species of essential oil were used to compare the alpha-glucosidase inhibitory activity with that of Zanthoxylum bungeanum essential oil.
Reply: We were really sorry for our careless mistakes. Thank you for your reminder and corrected in the revised manuscript.
- Line 33 and 49: move the citation to the end of the sentence.
- Line 68: delete “in Table3”
- The unshielded particles and sieved powder were sampled in the ratio of 1:2. This sentence is not clear; please revise it.
Reply: We have corrected it in the revised manuscript.
- Line 42-43: e. The aroma of Zanthoxylum bungeanum fruit is because it contains a lot of essential oil. Please explain what kind of essential oil.
Reply: Zanthoxylum bungeanum has a strong aroma. Because it contains a large number of monoterpenes, which exist in the essential oil of Zanthoxylum bungeanum and volatilize to produce aroma.
- Section 2.3: Please specify the time for sample collection (Line 81) and the temperature of the distillation method (Line 85). In addition, please separate the steam distillation and eutectic solvent procedures.
Reply: We have specified the time ‘1.0h’, the temperature ‘100℃’, and separated the procedures.
- Line 86: Please use an article instead of the number.
Reply: We have replaced it.
- After adding sodium carbonate solution (1.0 mol/L)100 μL the reaction was terminated, and the absorbance of the test solution was measured at 405 nm. Please revise it.
Reply: We have corrected it in the revised manuscript.
- It is necessary to explain what kind of extraction method is best to extract essential oil from Zanthoxylum bungeanum.
Reply: We have explained it and given it in the red text.
- Figure 1, please provide more detail for the figure legend.
Reply：We have added relevant information about the yield rate in Figure 1.
- It is reported that although 26 varieties of Zanthoxylum pericarp extracts and main Inhibitory Ingredients against α-glucosidase were measured13, the inhibitory on α-glucosidase activities of different species of plant essential oils were compared in this paper. This sentence is not clear; please revise it.
Reply: Thank you for your suggestion. We have tried our best to polish the language in the revised manuscript.
- In Figure 2, can the authors provide the name of the arrow and the compounds?
Reply: We feel great thanks for your professional review work on our article. We use essential oils from 20 species as a test material, the chemical composition of each essential oil is complex, in addition to peppercorn essential oil, the chemical composition of other essential oils we have not tested, or the datum are too many to be listed in the table. Many papers also list in this way, such as (1) Lin CH, Chao LK, Lin LY, Wu CS, Chu LP, Huang CH, Chen HC. Analysis of Volatile Compounds from Different Parts of Houttuynia cordata Thunb. Molecules. 2022 Dec 14;27(24):8893. doi: 10.3390/molecules27248893., (2) Liu SM, Wang SJ, Song SY, Zou Y, Wang JR, Sun BY. Characteristic differences in essential oil composition of six Zanthoxylum bungeanum Maxim. (Rutaceae) cultivars and their biological significance. (3) J Zhejiang Univ Sci B. 2017 Oct.;18(10):917-920. doi: 10.1631/jzus.B1700232.’ and so on.
- It will be better to provide all the compounds found in Zanthoxylum bungeanum essential oil.
Reply: The matching rate in MS of other components has not reached 80%,
so it is not certain whether it is accurate.
- It would be better to provide the molecular docking scores or binding affinities (kcal/mol) of the main compounds in a table form.
- The conclusion of this work should be revised to cover all experiments.
Reply：We thank the reviewer for the constructive comments. We have re-written these parts according to the reviewer’s suggestion.
-Those are close to the binding energy between anthocyanins…. Did the authors use anthocyanins to evaluate in comparison with the essential oil of Zanthoxylum bungeanum?
Reply: We compared the data with the literature ‘Promyos N, Temviriyanukul P, Suttisansanee U. Investigation of Anthocyanidins and Anthocyanins for Targeting α-Glucosidase in Diabetes Mellitus. Prev Nutr Food Sci. 2020 Sep 30;25(3):263-271. doi: 10.3746/pnf.2020.25.3.263.’, and found that the binding energy between the components of Zanthoxylum bungeanum essential oil and α-glucosidase is similar to that of anthocyanins.
-Did the authors know the extraction method used for extracting the essential oil from other species? If a different method was used, how does it compare in terms of alpha-glucosidase inhibitory activity to the extraction method used for Zanthoxylum bungeanum?
Reply: Generally, it is steam distillation, but also enzyme assisted extraction, ultrasonic assisted extraction, microwave assisted extraction and so on. Due to the improvement in the method of steam distillation, generally do not change the composition of the compound, so there is no difference in inhibitory activity.
-Please provide a discussion regarding the absence of limonene and linalool in the essential oil of Zanthoxylum bungeanum.
Reply: These two components are found in various literatures. The reason why they are not detected in this paper may be that the mass spectrum fails to recognize them or the geographical distribution causes the difference of components.
We tried our best to improve the manuscript and made some changes in the manuscript. We appreciate for Reviewers' warm work earnestly, and hope that the correction will meet with approval. Once again thank you very much for your comments and suggestions.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Title: Zanthoxylum bungeanum Essential Oil: Extraction, Component Analysis, against α-Glucosidase Activity and Mechanism
General comments
The paper is well written and should be accepted after minor modification
Comments
Ø The title of the manuscript needs modification. As for activity no lab experiment was performed, hence title must contain the word molecular docking study Or In silico study.
Ø Line 26,27. The keywords writing style not correct make capital the first word and too long key words.
Ø Experimental research and field studies on plants (either cultivated or wild), including the collection of plant material, must comply with relevant institutional, national, and international guidelines and legislation. Hence, we request you provide a statement to confirm that all methods were carried out in accordance with the relevant guidelines in the method section.
Ø The abstract should contain the conclusion and future perspective of you work
Ø In table 3 It is better to give your result in the retention index in place of retention time. Retention index, is used to convert retention times into system-independent constants.
Ø Your conclusion is too small please include more information. The conclusion must contain the main finding with a conclusion and recommendation
Author Response
Dear Editors and Reviewers:
Thank you for your letter and for the reviewers" comments concerning our
manuscript entitled ‘Zanthoxylum bungeanum Essential Oil: Extraction, Component Analysis, against α-Glucosidase Activity and Mechanism’ (applsci-2215924). Those comments are all valuable and very helpful for revising and improving our paper. We have studied comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and the responds to the reviewer's comments are as flowing:
The title of the manuscript needs modification. As for activity no lab experiment was performed, hence title must contain the word molecular docking study Or In silico study.
Reply: Thanks for your suggestion. We have corrected it.
Ø Line 26,27. The keywords writing style not correct make capital the first word and too long key words.
Reply: We have reduced keywords.
Ø The abstract should contain the conclusion and future perspective of you work
Reply：We have added relevant content in the revised manuscript.
Ø Your conclusion is too small please include more information. The conclusion must contain the main finding with a conclusion and recommendation
Reply: We accept all the above suggestions and these have been reflected in the revised manuscript.
Ø Experimental research and field studies on plants (either cultivated or wild), including the collection of plant material, must comply with relevant institutional, national, and international guidelines and legislation. Hence, we request you provide a statement to confirm that all methods were carried out in accordance with the relevant guidelines in the method section.
Reply: We have provided you with a plant material collection statement in the revised manuscript.
Ø In table 3 It is better to give your result in the retention index in place of retention time. Retention index, is used to convert retention times into system-independent constants.
Reply: Thank you for your suggestion. Although the expression of retention index is very good, there are also quite a number of literatures using retention time, so we think retention time is also feasible. Such as: Tanapichatsakul C, Khruengsai S, Pripdeevech P. In vitro and in vivo antifungal activity of Cuminum cyminum essential oil against Aspergillus aculeatus causing bunch rot of postharvest grapes. PLoS One. 2020 Nov 24;15(11):e0242862. doi: 10.1371/journal.pone.0242862.
We tried our best to improve the manuscript and made some changes in the manuscript. We appreciate for Reviewers' warm work earnestly, and hope that the correction will meet with approval. Once again thank you very much for your comments and suggestions.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Thank you for improving your manuscript and responding to my query. The manuscript is improving.
