Discovery, synthesis, and optimization of antimalarial 4(1H)-quinolone-3-diarylethers.
The historical antimalarial compound endochin served as a structural lead for optimization. Endochin-like quinolones (ELQ) were prepared by a novel chemical route and assessed for in vitro activity against multidrug resistant strains of Plasmodium falciparum and against malaria infections in mice. Here we describe the pathway to discovery of a potent class of orally active antimalarial 4(1H)-quinolone-3-diarylethers. The initial prototype, ELQ-233, exhibited low nanomolar IC50 values against all tested strains including clinical isolates harboring resistance to atovaquone. ELQ-271 represented the next critical step in the iterative optimization process, as it was stable to metabolism and highly effective in vivo. Continued analoging revealed that the substitution pattern on the benzenoid ring of the quinolone core significantly influenced reactivity with the host enzyme. This finding led to the rational design of highly selective ELQs with outstanding oral efficacy against murine malaria that is superior to established antimalarials chloroquine and atovaquone.
VA Medical Center , 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States.
Aaron
A
Nilsen
Galen P
GP
Miley
Isaac P
IP
Forquer
Michael W
MW
Mather
Kasiram
K
Katneni
Yuexin
Y
Li
Sovitj
S
Pou
April M
AM
Pershing
Allison M
AM
Stickles
Eileen
E
Ryan
Jane Xu
JX
Kelly
J Stone
JS
Doggett
Karen L
KL
White
David J
DJ
Hinrichs
Rolf W
RW
Winter
Susan A
SA
Charman
Lev N
LN
Zakharov
Ian
I
Bathurst
Jeremy N
JN
Burrows
Akhil B
AB
Vaidya
Michael K
MK
Riscoe
D000818:Animals; D000962:Antimalarials / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D055808:Drug Discovery; D057809:HEK293 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D010963:Plasmodium falciparum / Q000187:drug effects*; D015363:Quinolones / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D021241:Spectrometry, Mass, Electrospray Ionization
D000962:Antimalarials; D015363:Quinolones