Structural Characterization and In Vitro Antioxidant, Hypoglycemic and Hypolipemic Activities of a Natural Polysaccharide from Liupao Tea

Round 1

Reviewer 1 Report

My main comments:

- keywords must not duplicate with the title

- introduction: novum emphasis is missing; please specify: research problem, purpose, research hypothesis

- methodology - this is a big mess; please create descriptions in a clearer way; any equipment used, please state according to the formula: name (model, manufacturer, city, country)

- 2.6.2 - what concentration of PNPG was used? Was a drug used for comparison, e.g. acarbose? if so, at what concentration?

- 2.7 - please provide FULL AND DETAILED DESCRIPTIONS

- 2.8 - if the number of samples is less than 20, use non-parametric analysis

- Graphs 4-7 - not very legible, low quality; please enlarge them, make them editorially uniform, provide better quality

- conclusions-refer to the hypothesis posed in the introduction

The language of the text is very hard to read - linguistic correction by a Native Speaker is necessary.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments for author File: Comments.docx

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The work was adequately conducted and presents some elements of novelty in the elucidation of the polysaccharide. Some points must be corrected .

Pg 1, L38-40: Add supporting references to statements.

Pg 2 L45-48: Add supporting references to assertions.

Pg 3, L129-131: It better describes the methodology used. How the data were processed, and the criteria used to obtain the structure. Structural evaluation by spectrophotometry is normally performed in FTIR, given the limitations of UV/Vis for sugar elucidation. Since in section 2.3.4 the use of FTIR is mentioned.

Section 2.3.3: Provide more details of the chromatographic analysis. Elution solvent, column temperature, flow, and method linearity and detection limits.

Section 2.4.1: Was the antioxidant capacity assessment method developed by Chen’s? Explain the reaction time of only 20 min. for DPPH, as it is too short for most common methodologies.

Section 2.7: replace title with spectrophotometric analysis of sugars, proteins and total polyphenols. For the hallucination of chemical composition requires instrumental techniques at the molecular level.

Fig 2C. Unable to observe UV/Vis absorption bands

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Accept in present form

Author Response

Dear review：

Thank you very much for your comments and professional advice.  Those opinions help to improve academic rigor of our article. Thank you very much for your approval of the revised manuscript.

Best wishes for you！

Sincerely,

Lu Wei, Li Huang, Lijuan Du, Qinju Sun, Can Chen, Jie Tang, Jianwen Teng and Baoyao Wei.

Author Response File: Author Response.doc