Synthesis of Amino Acid-Naphthoquinones and In Vitro Studies on Cervical and Breast Cell Lines.

We performed an extensive analysis about the reaction conditions of the 1,4-Michael addition of amino acids to 1,4-naphthoquinone and substitution to 2,3-dichloronaphthoquinone, and a complete evaluation of stoichiometry, use of different bases, and the pH influence was performed. We were able to show that microwave-assisted synthesis is the best method for the synthesis of naphthoquinone-amino acid and chloride-naphthoquinone-amino acid derivatives with 79-91% and 78-91% yields, respectively. The cyclic voltammetry profiles showed that both series of naphthoquinone-amino acid derivatives mainly display one quasi-reversible redox reaction process. Interestingly, it was shown that naphthoquinone derivatives possess a selective antitumorigenic activity against cervix cancer cell lines and chloride-naphthoquinone-amino acid derivatives against breast cancer cell lines. Furthermore, the newly synthetized compounds with asparagine-naphthoquinones (3e and 4e) inhibited ~85% of SiHa cell proliferation. These results show promising compounds for specific cervical and breast cancer treatment.

Effect of the tri-sodium citrate as a complexing agent in the deposition of ZnS by SILAR.

Using the SILAR method Zinc sulfide coatings were deposited on glass slices. The physical properties and the chemical mechanism throughout the variation in concentration of tri-sodium citrate (TSC) as a chelating agent in the synthesis of thin films were investigated. Results shows that ZnS thin films exhibit an average transmittance of 16% in visible light spectra region and a zinc blende structure. The ZnS films synthesized using TSC as a complexing agent, present a smaller average particle size, an average transmittance of 85%, and an adsorption edge at 300-340 nm. Based on our experimental data and analysis, we conclude that the contribution of the oxychloride species, a subproduct in the chemical deposition, is suggested to be related as an impurity level former in the synthesis of ZnS thin films. TSC as a complexing agent in the SILAR technique is a non-toxic option to reduce the generation of the oxychloride species and synthesize a wide band gap semiconductor. Moreover, the use of complexing agents could be extended to other types of semiconductors deposited by SILAR.