Nature of Electrogenerated Intermediates in Nitro-Substituted Nor-β-lapachones: The Structure of Radical Species during Successive Electron Transfer in Multiredox Centers

Electrochemical, spectroelectrochemical, and theoretical studies of the reduction reactions in nor-β-lapachone derivatives including a nitro redox center showed that reduction of the compounds involves the formation of several radical intermediates, including a biradical dianion resultant from the separate reduction of the quinone and nitro groups in the molecules. Theoretical descriptions of the corresponding Fukui functions <i>f</i>_αα⁺ and <i>f</i>_ββ⁺(<b>r</b>) and LUMO densities considering finite differences and frozen core approximations for describing the changes in electron and spin densities of the system allowed us to confirm these results. A description of the potential relationship with the obtained results and biological activity selectivity indexes suggests that both the formation of stable biradical dianion species and the stability of the semiquinone intermediates during further reduction are determining factors in the description of their biological activity

Synthesis of novel 1,4-naphthoquinone derivatives: antibacterial and antifungal agents

A novel series of substituted 1,4-naphthoquinone derivatives was synthesized and evaluated for antibacterial and antifungal activity. The structures of the novel products were characterized by spectroscopic methods. Among the tested compounds, 3a and 9 are the most effective compounds against M. luteum as potent antibacterial and C. tenuis and A. niger as potent antifungal. These two compounds are promising as biologically active compounds