5,5′-Oxybis(1,3,7-trihydroxy-9H-xanthen-9-one): A New Xanthone from the Stem Bark of Garcinia porrecta (Clusiaceae)
Round 1
Reviewer 1 Report
The authors have modified the last version of the manuscript, eliminating information related to the evaluation of antitumor activity. Although that data was not very promising and the authors have evaluated only one tumor cell line (without justifying the choice of that line…), it was more data related to the isolated xanthone. However, I consider that this “short note” focused only on the isolation and characterization of xanthone will find a suitable interest for a number of readers of Molbank and can be accepted in the current form.
Author Response
Answer to Reviewer-1
Comments:
The authors have modified the last version of the manuscript, eliminating information related to the evaluation of antitumor activity. Although that data was not very promising and the authors have evaluated only one tumor cell line (without justifying the choice of that line…), it was more data related to the isolated xanthone. However, I consider that this “short note” focused only on the isolation and characterization of xanthone will find a suitable interest for a number of readers of Molbank and can be accepted in the current form.
Answers: We had already modified in line with reviewers and editor suggestion.
Author Response File: Author Response.docx
Reviewer 2 Report
The NMR spectra provided look cleaner compared to the ones submitted in an earlier version of the manuscript, however, in the experimental method the purification looks exactly the same. How was the cleaner sample obtained? shouldn't be this described in the experimental section?
Author Response
Answer to reviewer-2
Comments:
The NMR spectra provided look cleaner compared to the ones submitted in an earlier version of the manuscript, however, in the experimental method the purification looks exactly the same. How was the cleaner sample obtained? shouldn't be this described in the experimental section?
Answer: Actually, we do not measure NMR spectra due to the limitation of quantity, we only provide original FID of the NMR spectra.
Indeed meta Hs can have a small J coupling. I did find a similar compound in the literature, 1,3,7-trihydroxy-5-methoxyxanthone, and the small J couplings are observable, also the compound gentisein that the authors compare to has this small coupling.
If the shimming is not very good, the splitting might not be observable, or if the sample it is too concentrated then the peaks can be broad and this will also result in missing the J coupling.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Your response makes no sense and does not answer my question.
Author Response
Answer to Reviewer
Comments:
- The NMR spectra provided look cleaner compared to the ones submitted in an earlier version of the manuscript, however, in the experimental method the purification looks exactly the same. How was the cleaner sample obtained? shouldn't be this described in the experimental section?
- Your response makes no sense and does not answer my question.
Answers:
In the experimental method the purification exactly the same. The isolated remains in small quantities and impossible to purify and measure NMR again. So, we only provide original FID of the NMR spectra.
Author Response File: Author Response.docx