Synthesis and NLRP3-Inflammasome Inhibitory Activity of the Naturally Occurring Velutone F and of Its Non-Natural Regioisomeric Chalconoids
, Mariasole Perrone 2,3,†, Sonia Missiroli 2,3, Paolo Pinton 2,3,4, Paolo Marchetti 1, Giovanni Strazzabosco 1, Giulia Turrin 1, Davide Illuminati 1, Virginia Cristofori 1, Anna Fantinati 5, Martina Fabbri 1, Carlotta Giorgi 2,3,*, Claudio Trapella 1,3,* and Vinicio Zanirato 1Round 1
Reviewer 1 Report
The authors of the article take up the current topic of searching for analogues of a relatively new compound, which is velutone F. The search results in finding 3 active derivatives (22,23,28) with NLRP3-inflammasome inhibitors activity. The authors present ingenious pathways for the synthesis of individual substrates, demonstrating the knowledge of chemical synthesis. The obtained structures are confirmed by the spectra of NMR, IR, MS and HRMS spectroscopy. In addition, biological tests confirm very good, and sometimes better biological properties than the mentioned F velutone (1). Each section has a typical layout (Introduction, Results and discussion, Materials and methods, Conclusions). The whole thing is combined into a logically planned whole of research that has been properly carried out. The authors did not notice some shortcomings, which, however, do not affect the substantive reception of the work.
Main remarks:
1) Line 26: abbreviations should not be italicized.
2) Line 46: "Velutone F" should be in normal font, no italics.
3) If relationships 22, 23, 28 and others were new, it should be emphasized in the text, including the abstract.
4) Line 115: "Millettia velutina" should be in italics.
5) In the descriptions under the diagrams of all syntheses there is no differentiation of subscripts, eg it should be "H2SO4" and not "H2SO4", etc. Please correct.
6) "trans" in names should be italic.
7) Lines 146, 162: "O" should be in italics.
8) Line 221: why was step "d" not performed using microwaves? Please explain.
9) Entire article and charts: it should be "mL" and not "ml". The same for "ng/mL", "ug/mL" etc. Please correct.
10) Line 268: "in vitro" and "in vivo" should be in italics.
11) Line 235: there should probably be a different section number. Number 3 is the "Materials and Methods" section. Please check and correct the numbering of the individual sections.
12) The signature in Figure 3 should not be in italics.
13) Materials and methods: Please add manufacturers, cities and countries for each equipment used.
14) Line 293: on what equipment was the HRMS performed. Please add.
15) Section 3.18: it should be "g" and not "gr"
16) Line 527: "a microwave vial" - please add the type - glass, quartz, Teflon and its volume. If it is mentioned in some other synthesis, please also specify. This can also be added to the materials and methods at the beginning of section 3.
17) What was the purity of the chalcones used in biological research? On what basis was it determined? Please add.
18) Please write in the text of the manufacturer Sn-B-zeolite.
19) Line 581: it should be "Cs2CO3" and not "CsCO3".
20) Lines 610, 620: the compound name should be in italics.
21) Full article: there are sometimes missing spaces between numbers and units, numbers and signs of degrees Celsius. Please carefully track and correct.
22) I hope that the "non published materials" submitted for review will also be published as "supplementary materials"
Author Response
Ferrara, August 04 2022
Object: manuscript ID ijms-1839410, answer to Reviewer 1
Dear editor,
Thank you for having reviewed the manuscript and for considering it of potential interest for IJMS readers.
We report here below the reviewers’ questions / comments and our circumstantiated answers to all the points raised.
Reviewers answers:
Reviewer #1:
Comments:
R1 Line 26: abbreviations should not be italicized.
A1 Corrected
R2 Line 46: "Velutone F" should be in normal font, no italics.
A2 Corrected
R3 If relationships 22, 23, 28 and others were new, it should be emphasized in the text, including the abstract.
A3 The authors added in the text and also in the abstract a line to emphasized the novel molecular structures
R4 Line 115: "Millettia velutina" should be in italics.
A4 Corrected
R5 In the descriptions under the diagrams of all syntheses there is no differentiation of subscripts, eg it should be "H2SO4" and not "H2SO4", etc. Please correct.
A5 Corrected
R6 "trans" in names should be italic.
A6 Corrected
R7 Lines 146, 162: "O" should be in italics.
A7 Corrected
R8 Line 221: why was step "d" not performed using microwaves? Please explain.
A8 The reaction was carried out also in microwave condition, the yield and also the reaction time did not change from the classical heating and we decide to do the reaction in classical condition to increase the amount of compound synthesized.
R9 Entire article and charts: it should be "mL" and not "ml". The same for "ng/mL", "ug/mL" etc. Please correct.
A9 Corrected
R10 Line 268: "in vitro" and "in vivo" should be in italics.
A10 Corrected
R11 Line 235: there should probably be a different section number. Number 3 is the "Materials and Methods" section. Please check and correct the numbering of the individual sections.
A11 Corrected
R12 The signature in Figure 3 should not be in italics.
A12 Corrected
R13 Materials and methods: Please add manufacturers, cities and countries for each equipment used.
A13 We added in the material and methods all the information required by the reviewer.
R14 Line 293: on what equipment was the HRMS performed. Please add.
A14 We insert in the line 293 the instrument used for HRMS analysis
R15 Section 3.18: it should be "g" and not "gr"
A15 Corrected.
R16 Line 527: "a microwave vial" - please add the type - glass, quartz, Teflon and its volume. If it is mentioned in some other synthesis, please also specify. This can also be added to the materials and methods at the beginning of section 3.
A16 We added the information regarding the microwave vials in the materials and methods.
R17 ) What was the purity of the chalcones used in biological research? On what basis was it determined? Please add.
A17 The purity grade of the final chalcones used for biological analysis has been assessed by HPLC and HPLC-HRMS. All the HPLC spectra and HRMS spectra are in the supporting information file.
R18 Please write in the text of the manufacturer Sn-B-zeolite.
A18 done.
R19 Line 581: it should be "Cs2CO3" and not "CsCO3".
A19 Corrected
R20 Lines 610, 620: the compound name should be in italics.
A20 The authors changed the italics font.
R21 Full article: there are sometimes missing spaces between numbers and units, numbers and signs of degrees Celsius. Please carefully track and correct.
A21 Corrected
R22 I hope that the "non published materials" submitted for review will also be published as "supplementary materials"
A22 We hope so.
The new version of the manuscript should now fulfill the requirements for publication in the International Journal of Molecular Science.
We look forward to hearing from you soon.
With my very best regards
Prof. Claudio Trapella
Reviewer 2 Report
refer to the attached document
Comments for author File: 
Comments.pdf
Author Response
Ferrara, August 04 2022
Object: manuscript ID ijms-1839410, answer to Reviewer 2
Dear editor,
Thank you for having reviewed the manuscript and for considering it of potential interest for IJMS readers.
We report here below the reviewers’ questions / comments and our circumstantiated answers to all the points raised.
Reviewers answers:
Reviewer #2:
R1 line 8: 1Department of Chemistry change with 1Department of Chemistry
A1 Corrected
R2 line 78: in Figure 1 the word Velutone F it should be placed under the chemical structure and not sideways.
A2 Corrected
R3 scheme 1: remove the structure name “ 3-furanoic acid”, in a synthetic scheme it is not required to report the IUPAC nomenclature. In a similar way, remove “velutone F”, number 1 is sufficient.
A3 The IUPAC name has been removed from the schemes in all the manuscript.
R4 scheme 1: compound 4 has been synthesized starting from 3 (3.2. Methyl 3-(1,1,4-trimethoxy-4-oxobutyl)furan-2-carboxylate (4) [17]. A solution of compound (3) (0.9 gr, 3.75 mmol, 1 equiv.), HC(OMe)3(2.1 mL, 19.48 mmol, 5.2 equiv) line 319) while in the scheme it is synthesized starting from 2. Modify appropriately, in a similar way, compound 7 has been synthesized from 6.
A4 The scheme 1 has been changed to accomplish the referee request and has been clarified the reaction pathway.
R5 lines 119-123: Synthetic pathway A for target compound 1. Reagents and conditions: (a) i: LDA, THF, -78 °C, succinic anhydride; ii: dil.HCl; 35%; (b) MeOH, H2SO4, 90%; (c) HC(OMe)3, p-TsOH, MeOH rfx, 36 h, 90%; (d) i: t-BuOK, THF, -78 °C; ii: dil.HCl, 62%; (e) MeI, Cs2CO3, DMF, rt, 16 h, 96%; (f) i: LiAlH4, Et2O, 12 h; ii: PCC, CH2Cl2, rt, 1.5 h, 60% two steps; (g) MeCN, MW, 135 °C, 1.5 h, 70%. Use the appropriate formalisms. in particular the subscripts. Moreover, change rfx with reflux.
A5 We did the correction of all subscripts and also changed rfx with reflux.
R6 Line 130: tert-BuOH change with tert-BuOH.
A6 Corrected
R7 Scheme 2: as for the scheme 1 use the appropriate formalism (lines 136-143). Remove the IUPAC name (2,5-dimethoxy benzaldehyde) in the scheme.
A7 Corrected accordingly with scheme1 suggestion.
R8 Scheme 3: as the authors wrote “the resulting compound 18 was cyclized to 19 under the action of PPA (Sn zeolite also showed to efficiently promote this transformation [28]” but in the scheme 19 was synthesized from 8. Please make the concept clearer.
A8 The scheme was modified in accord with referee suggestion.
R9 lines 209-211: use the appropriate formalism and change rfx with reflux.
A9 Corrected
R10 scheme 4: as the authors wrote “compound 25 in two steps from phenol 8, namely: etherification with bromoacetone followed by acid-promoted cyclization of the resulting aryloxy acetone derivative 24” change the scheme appropriately.
A10 We did all the correction required by the reviewer.
R11 In the material and methods section starting from “A solution of compound (3) change with “A solution of compound 3” (lines 319-320) and in similar way “Title compound (4)” with “Title compound 4”. Please replace throughout the section (lines 330, 336, 340, 347, 351….
A11 All the correction required has been done.
The new version of the manuscript should now fulfill the requirements for publication in the International Journal of Molecular Science.
We look forward to hearing from you soon.
With my very best regards
Prof. Claudio Trapella
Round 2
Reviewer 2 Report
in schemes 3 and 4 compound 8 (3,5 dimethoxy phenol as reported) correspond to compound 9 (see scheme 2). Compound 8 is 1-Phenyl-2-(triphenyl-5-phosphaneylidene) ethan-1-one (8) [16] as authors wrote. It must be added that the correct IUPAC name is 1-phenyl-2-(triphenylphosphoranylidene)ethanone. In the end if compound 8 was synthesized as reported in literature, it is not necessary to report the synthesis (see lines 384-394). Change the numbering in the text as well.
Author Response
Dear reviewer,
Thank you for having reviewed the manuscript and for considering it of potential interest for IJMS readers.
We report here below the reviewers’ questions / comments and our circumstantiated answers to all the points raised.
Reviewers answers:
Reviewer #2:
R1: in schemes 3 and 4 compound 8 (3,5 dimethoxy phenol as reported) correspond to compound 9 (see scheme 2). Compound 8 is 1-Phenyl-2-(triphenyl-l5-phosphaneylidene) ethan-1-one (8) [16] as authors wrote. It must be added that the correct IUPAC name is 1-phenyl-2-(triphenylphosphoranylidene)ethanone. In the end if compound 8 was synthesized as reported in literature, it is not necessary to report the synthesis (see lines 384-394). Change the numbering in the text as well.
A1: In schemes 3 and 4 we reported the right number of the compound, which it was 9 as the referee noticed.
At the line 94 the IUPAC name of 8 is been corrected.
Lines 391-410 is been removed as suggested from referee because the synthesis of 8 was reported in literature.
We changed numbers in the text as well as suggested from referee #2.
The new version of the manuscript should now fulfill the requirements for publication in the International Journal of Molecular Science.
We look forward to hearing from you soon.
With my very best regards
Prof. Claudio Trapella
