Browsing by Author "Lappin, A. Graham"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    New benzimidazolequinones as trypanosomicidal agents
    (2021) Lopez-Lira, Claudia; Tapia, Ricardo A.; Herrera, Alejandra; Lapier, Michel; Maya, Juan D.; Soto-Delgado, Jorge; Oliver, Allen G.; Lappin, A. Graham; Uriarte, Eugenio
    Herein, the design and synthesis of new 2-phenyl(pyridinyl)benzimidazolequinones and their 5-phenoxy derivatives as potential anti-Trypanosoma cruzi agents are described. The compounds were evaluated in vitro against the epimastigotes and trypomastigote forms of Trypanosoma cruzi. The replacing of a benzene moiety in the naphthoquinone system by an imidazole enhanced the trypanosomicidal activity against Trypanosoma cruzi. Three of the tested compounds (11a-c) showed potent trypanosomicidal activity and compound 11a, with IC50 of 0.65 mu M on the trypomastigote form of T. cruzi, proved to be 15 times more active than nifurtimox. Additionally, molecular docking studies indicate that the quinone derivatives 11a-c could have a multitarget profile interacting preferentially with trypanothione reductase and Old Yellow Enzyme.
  • No Thumbnail Available
    Item
    Synthesis and characterization of low-melting ferrocenyl salts: a study of thermal and photochemical redox reactions
    (2018) Diaz, Carlos; Ferraudi, Guillermo; Lappin, A. Graham; Oliver, Allen; Isaacs, Mauricio
    The syntheses of bis(trifluoromethane) sulfonimide N-(ferrocenylmethyl) N,N,N-trimethyl ammonium salt 1 and bis(trifluoromethane) sulfonimide N',N-bis(ferrocenylmethyl) inmidazolium salt 2 are reported. The compounds show low melting points, 76 degrees and 125 degrees C, respectively, and were characterized by spectroscopic techniques H-1-NMR, mass spectrometry, FT-IR spectroscopy, cyclic voltammetry, and XRD crystallographic analysis. Cyclic voltammetry results demonstrate that both salts have a quasi-reversible electrochemical behavior, similar to the reversible one shown by ferrocene under the same conditions. In the case of 1, a coupled chemical reaction was detected at slow scan rates after the oxidation. Transient species in the redox processes were investigated using flash photolysis and pulse radiolysis. In both cases, transient spectra of the products were similar to transient spectra observed for ferrocene. The decay kinetics of the oxidized and reduced transients were examined and mechanistic information was obtained. The experimental results show the potential uses of the two complexes as catalytic materials for electrochemical applications.