Germacrane Sesquiterpene Dilactones from Mikania micrantha and Their Antibacterial and Cytotoxic Activity
, Shao-Bo Liu 1, Shan-Xuan Zhang 1, Meng-Fei Liu 1, Jin-Long Duan 1, Jin-Kui Ouyang 1, Jia-Tao Hu 1, Fen-Yu Fu 1 and Jian-Wen Tan 1,*Round 1
Reviewer 1 Report
I read this manuscript with great interest. It is a good article with certain innovation. The methods and conclusions adopted are reliable, and the data are also rich.
Minor issues,
1. Can you give each a concise common name for the four new compounds so that they can be easily indexed in the future.
2. Part 3.4, The initials of the four new compound names are suggested to be capitalized.
3. The arrow color in Figure 3 is best represented by red, because gray and black are not easy to distinguish.
4. Part 3.2, It is suggested to give the longitude and latitude of the picking site and indicate who identified the sample.
Author Response
- Can you give each a concise common name for the four new compounds so that they can be easily indexed in the future.
Our response: A concise common name for each of the four new compounds has now been respectively added in the last sentence of the paragraphs for each of the new compounds in the disccusion section.
- Part 3.4, The initials of the four new compound names are suggested to be capitalized.
Our response: The initial letter of each of the four new compound names has now been revised to their capitalized style.
- The arrow color in Figure 3 is best represented by red, because gray and black are not easy to distinguish.
Our response: The color of the arrows in Figure 3 has now been revised to red.
- Part 3.2, It is suggested to give the longitude and latitude of the picking site and indicate who identified the sample.
Our response: We have now added the information for the person who identified the sample in the revised version manuscript.
Reviewer 2 Report
The Authors of the submitted manuscript presented a work where they have isolated sesquiterpene dilactones from the plant M. micrantha. The isolated compounds were tested regarding their antibacterial activity on 7 strains of bacteria and 4 different types of cell lines.
The manuscipt is well designed and the series of experiments are clearly described.
On the other hands, please find my comments:
line 49-52: at its native homeland in Mexico, M. micrantha 49 has long been used as a traditional folk remedy for the treatments of skin diseases... in Jamaica as a 51 traditional herbal medicine to treat skin itches and athlete’s foot.
Among the 4 cell lines I cannot find any immortalized keratinocyte cell lines.
Please explain the selection criterias of the cell lines!
In Table 3. MIC values of compounds 1−9 are given in µg/mL, while in Table 4. the IC50 values of compounds 1–9, are represented in µM!
Please, consider to compare those values using the same unit of concentration!
Compounds 1-9 were separated from the EtOAc extract.
Please consider to discuss the aqueous solublity of compound, this would be neccesary, since all of your experiments were condusted in aqueous media!
Author Response
On the other hands, please find my comments:
line 49-52: at its native homeland in Mexico, M. micrantha has long been used as a traditional folk remedy for the treatments of skin diseases... in Jamaica as a traditional herbal medicine to treat skin itches and athlete’s foot.
Our response: We have now optimized the sentence as “it is very interesting to know that, in Mexico, M. micrantha has long been used as a traditional folk remedy for the treatments of skin diseases, snake bites and scorpion stings. Also, this plant has long been used in Jamaica as a traditional herbal medicine to treat skin itches and athlete’s foot”.
Among the 4 cell lines I cannot find any immortalized keratinocyte cell lines.
Please explain the selection criterias of the cell lines!
Our response: We use these four cancer cell lines in the cytotoxic assay because they were presently available for us. We will consider to include immortalized keratinocyte cell lines in the bioassy in our further studies.
In Table 3. MIC values of compounds 1−9 are given in µg/mL, while in Table 4. the IC50 values of compounds 1–9, are represented in µM!
Please, consider to compare those values using the same unit of concentration!
Our response: After careful analysis and comparison with related literatures, we think to maintain the present unit ‘µg/mL’ for the MIC values and the unit ‘mM’ for the cytotoxicity would be proper, because in our experiment, the concentrations for testing the MIC values of those compounds were initially preset in µg/mL. In the research afterwards, we will consider to preset the initial concentrations in the unit of µM for the MIC test.
Compounds 1-9 were separated from the EtOAc extract.
Please consider to discuss the aqueous solublity of compound, this would be neccesary, since all of your experiments were condusted in aqueous media!
Our response: We have carefully considered this suggestion. However, since that in our bioassay these compounds for the tests were all well dispersed (dissolved) in the corresponding aqueous media by using DMSO and slight ultrasonic solubilization, and the use of DMSO has already been mentioned in the experimental part, so we think it might not be quite necessary to again add a special description about the water solubility in the discussion section.
