Development and Validation of a HPLC–PDA Method for the Simultaneous Determination of Berberine, Palmatine, Geniposide, and Paeoniflorin in Haedoksamul-tang
Round 1
Reviewer 1 Report
The work presents in the paper is very simple but interesting at the same time. It is worth note that Asia countries have a long story in terms of botanical medicine, and founding more information in the literature about them is a pleasure.
Despite this, I have some points that the authors must clarify:
- p 3.1: all compounds studied in this work have a very particular UV-spectrum with 3-4 lambs max. For the method optimization, the wavelengths chosen are: "230, 230, 240, and 230 nm were selected for berberine, palmatine, geniposide, and paeoniflorin, respectively" . Why did you choose those and not those at 340 nm? I suppose that a natural extract has different minor compounds with a variable absorbance at 230 nm, reaching as well as the solvent cut-off (methanol: 210 nm). The author should motivate the chosen and an eventual explanation regarding the low interference not encountered.
- The extract should be rich in other bioactive compounds as phenols, anthocyanins etc. Why did the author detect any traces? it will be necessary that the author will show a chromatogram at 300 nm, in this way the evidence of method specificity will be confirmed.
- Fig 3. the axis are missed of the unit of measurement
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
- R 34: revise text (,,used to be used...“ )
2.1. Unclear text: ,, Structures of the eight ? compounds….”. Revise (if it’s necessary) the text of entire paragraph
2.3. Justify the use of aqueous HTS solution, while standards are methanolic solutions
2.5. The validation study should be completed with data on the stability of solutions (especially aqueous HST solution)
3.3.: Declare how many tests were performed (n=?)
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Thank you to the authors for the detailed responses. By now, some aspects are more clarified.
