Comparison of Nonheme Manganese- and Iron-Containing Flavone Synthase Mimics

Round 1

Reviewer 1 Report

This paper deals with non-heme Mn- and Fe-containing flavone synthase mimetics.

Formal points:

Please add to all references DOI (as requested in the template).

Doublecheck all references - use correct abbreviations for the journals.

For the titles of the papers, pls use small letters - not like e.g. ref #13.

Italicize all names of taxa (microorganisms etc.) - in references and in the whole MS. Italicize all ortho etc.

Add the section "Author contributions" as in the template.

It seems that you used an old template, pls. note that from 2/21 new template must be used. Doublecheck pls. instructions for authors, template for MS and refer to some very recent papers from this journal.

Use for all units in the tables square brackets (all tables). Remove grid from tables (e.g. Tab. 3.

Doublecheck writing of units, e.g. l. 343 must be μL - and elsewhere.

line 384 should be ...The relative reactivity..

Synthesis of flavones is very topical problem and they find more and more application in various biological application. Therefore any new method avoiding typical multi-step synthesis of these complex skeletons are welcome. This paper present novel, applicable methodology for preparation of the complex compounds. Methods are fully appropriate and results are well documented with respective and detailed spectral (NMR, MS) analyses. 

Altogether, this is very good and interesting paper that deserves publication after the minor revision.

Author Response

Dear reviewer, I have made the necessary changes (format of tables, references, doi numbers...) and have clearly marked them in the revised version. I also included "Author Contributions" and "Supplementary Materials."

I hope that our paper in the present form is suitable for the publication.

Best regards,

József Kaizer

Reviewer 2 Report

Flavones are groups of natural compounds which are found in vegetables, grains, bark, roots, stems and flowers. These natural products are now considered as an important component in a variety of medicinal and cosmetic applications. Flavones show a wide range of biological activity, such as antioxidant effects and inhibition of cell proliferation. Flavones can be synthesized by various methods including from o-hydroxyacetophenone, and oxidation of flavanones using various stoichiometric inorganic and organic reagents. The oxidation of flavanones by heme and nonheme iron-dependent enzymes is one of the most important steps during the biosynthesis of flavones.

The manuscript examines of nonheme manganese- and iron-containing flavone synthase mimics.

Authors performed stoichiometric and catalytic oxidation reactions of flavanone with spectroscopically well-characterized nonheme oxoiron(IV) intermediates compared to their analogous oxomanganese(IV) compounds. The catalytic activity of three iron and two manganese complexes was investigated by oxidizing flavanone using the oxidant mCPBA. They reported the first example of efficient oxidation of flavanone by iron and manganese complexes.

The structure of the synthesized compounds is unambiguously proved on the basis of NMR spectral data and HPLC-MS. In addition, a single-crystal structure was obtained for the new Fe(II) complex.

The article is clear and well written, it can be of great interest to the readers.

Author Response

Dear reviewer, I have made the necessary changes (format of tables, references, doi numbers) and have clearly marked them in the revised version. I also included "Author Contributions" and "Supplementary Materials."

I hope that our paper in the present form is suitable for the publication.

Best regards,

József Kaizer