The manuscript describes the investigations related to designed and synthesized copper complexes, which was full characterized. Theoretical studied supported the structures of the complexes wit missing crystal structure not determinated. Cytotoxic activity of the compounds was tested on cell lines MCF7 and HepG2 cancer cells and non-tumorigenic cells. Generation of ROS was elevated.

From my point of view, the title is correct. The organization and the aims are clear, and reading is easy. Abstract describes the study performed and the objectives of the paper. In my opinion, references are relevant and recent. The background is appropriate and the importance of the developed study is mentioned. Researcher goals are clear and the introduction is in relation with the conclusions and the work. The used methodology was clear and the relevant references were cited. The syntheses of the new compounds were carful described, as well as, the theoretical studies. The biological studies were correctly implement and detailed in the manuscript.

Data are results are relevant, clear and correctly discussed. The results were properly obtained an interpreted to achieve the objectives of the paper. The results of the properties and cytotoxicity of the compounds were compared in order to indicate the better potential anticancer agent. The discussion is developed in order to response to the question stablished by the author. The structures of the new complexes was interesting as metallo drugs and were correctly described. The possible mechanism of cell death caused by the compounds is indicated and suitably addressed.

The conclusion is in accordance with the aims of the paper. Conclusions highlight the more relevant results and the importance of them. The conclusion described briefly the used methodology.

The stability is an important factor for potential drug. Thus, authors could include the stability of the compounds in aqueous solution.

Finally, many copper complexes were synthetized and tested as anticancer agents in the recent years. Author could include more examples of them.