Identification, Design and Biological Evaluation of Heterocyclic Quinolones Targeting <i>Plasmodium falciparum</i> Type II NADH:Quinone Oxidoreductase (PfNDH2)
作者:Suet C. Leung、Peter Gibbons、Richard Amewu、Gemma L. Nixon、Chandrakala Pidathala、W. David Hong、Bénédicte Pacorel、Neil G. Berry、Raman Sharma、Paul A. Stocks、Abhishek Srivastava、Alison E. Shone、Sitthivut Charoensutthivarakul、Lee Taylor、Olivier Berger、Alison Mbekeani、Alasdair Hill、Nicholas E. Fisher、Ashley J. Warman、Giancarlo A. Biagini、Stephen A. Ward、Paul M. O’Neill
DOI:10.1021/jm201184h
日期:2012.3.8
Following a program undertaken to identify hit compounds against NADH:ubiquinone oxidoreductase (PfNDH2), a novel enzyme target within the malaria parasite Plasmodium falciparum, hit to lead optimization led to identification of CK-2-68, a molecule suitable for further development. In order to reduce ClogP and improve solubility of CK-2-68 incorporation of a variety of heterocycles, within the side chain of the quinolone core, was carried out, and this approach led to a lead compound SL-2-25 (8b). 8b has IC(50)s in the nanomolar range versus both the enzyme and whole cell P. falciparum (IC50 = 15 nM PfNDH2; IC50 = 54 nM (3D7 strain of P. falciparum) with notable oral activity of ED50/ED90 of 1.87/4.72 mg/kg versus Plasmodium berghei (NS Strain) in a murine model of malaria when formulated as a phosphate salt. Analogues in this series also demonstrate nanomolar activity against the bc(1) complex of P. falciparum providing the potential added benefit of a dual mechanism of action. The potent oral activity of 2-pyridyl quinolones underlines the potential of this template for further lead optimization studies.