n-alkylamino analogs of Vitamin K3: Electrochemical, DFT and anticancer activity of their oxidized and one electron reduced form

• Published in: Journal of molecular structure 2019-03, Vol.1179, p.443-452
• Main Authors: Chadar, Dattatray, Banerjee, Priyabrata, Saha, Sourav Kr, Bhand, Sujit, Patil, Rajendra, Salunke-Gawali, Sunita
• Format: Article
• Language: English
• Subjects: Aminonaphthoquinone; Anticancer activity; Catechol; Semiquinone; Vitamin K3
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2018.11.024

Synthesis, characterization and anticancer activity of reduced form of n-alkylamino analogs of Vitamin K3 (1Na to 8Na) are undertaken. Molecular structure and molecular association of oxidized form of 2-ethylamino-3-methyl-1,4-naphthoquinone (2) and 2-hexylamino-3-methyl-1,4-naphthoquinone (6) were studied by single crystal X-ray analysis. 2 crystallize in monoclinic C2/c and 6 in P21 space group. The reduced form of eight homologated analogs of 2-(n-alkylamino)-3-methyl-1,4-naphthoquinone (1Na to 8Na) were synthesized using sodium metal as reductant at 0 °C in methanol. The formations of naphthosemiquinone radical in 1 to 6 have been confirmed from their EPR spectra. Polycrystalline powder X-band EPR spectra of 1 to 6 shows signals ∼2.0020 ± 0.0026 at 133 K. Anticancer activity of 2-(n-alkylamino)-3-methyl-1,4-naphthoquinone (1Na to 8Na) and one electron reduced forms have been evaluated against breast cancer (HeLa) cell line, 1 and 1Na showed promising anticancer activity. [Display omitted] •Reduced form of aminonaphthoquinones of vitamin K3 synthesized chemically.•Radical signatures are confirmed by EPR studies.•Redox behavior is studied by cyclic voltammetry.•Compounds were optimized to three different redox forms by DFT.•Anticancer activity evaluated for oxidized and reduced form of the compounds.