TY - JOUR
T1 - Bioisosteric transformations and permutations in the triazolopyrimidine scaffold to identify the minimum pharmacophore required for inhibitory activity against plasmodium falciparum dihydroorotate dehydrogenase
AU - Marwaha, Alka
AU - White, John
AU - El-mazouni, Farah
AU - Creason, Sharon A.
AU - Kokkonda, Sreekanth
AU - Buckner, Frederick S.
AU - Charman, Susan A.
AU - Phillips, Margaret A.
AU - Rathod, Pradipsinh K.
PY - 2012/9/13
Y1 - 2012/9/13
N2 - Plasmodium falciparum causes approximately 1 million deaths annually. However, increasing resistance imposes a continuous threat to existing drug therapies. We previously reported a number of potent and selective triazolopyrimidine-based inhibitors of P. falciparum dihydroorotate dehydrogenase that inhibit parasite in vitro growth with similar activity. Lead optimization of this series led to the recent identification of a preclinical candidate, showing good activity against P. falciparum in mice. As part of a backup program around this scaffold, we explored heteroatom rearrangement and substitution in the triazolopyrimidine ring and have identified several other ring configurations that are active as PfDHODH inhibitors. The imidazo[1,2-a]pyrimidines were shown to bind somewhat more potently than the triazolopyrimidines depending on the nature of the amino aniline substitution. DSM151, the best candidate in this series, binds with 4-fold better affinity (PfDHODH IC50 = 0.077 μM) than the equivalent triazolopyrimidine and suppresses parasites in vivo in the Plasmodium berghei model.
AB - Plasmodium falciparum causes approximately 1 million deaths annually. However, increasing resistance imposes a continuous threat to existing drug therapies. We previously reported a number of potent and selective triazolopyrimidine-based inhibitors of P. falciparum dihydroorotate dehydrogenase that inhibit parasite in vitro growth with similar activity. Lead optimization of this series led to the recent identification of a preclinical candidate, showing good activity against P. falciparum in mice. As part of a backup program around this scaffold, we explored heteroatom rearrangement and substitution in the triazolopyrimidine ring and have identified several other ring configurations that are active as PfDHODH inhibitors. The imidazo[1,2-a]pyrimidines were shown to bind somewhat more potently than the triazolopyrimidines depending on the nature of the amino aniline substitution. DSM151, the best candidate in this series, binds with 4-fold better affinity (PfDHODH IC50 = 0.077 μM) than the equivalent triazolopyrimidine and suppresses parasites in vivo in the Plasmodium berghei model.
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U2 - 10.1021/jm300351w
DO - 10.1021/jm300351w
M3 - Article
C2 - 22877245
AN - SCOPUS:84866308294
SN - 0022-2623
VL - 55
SP - 7425
EP - 7436
JO - Journal of Medicinal Chemistry
JF - Journal of Medicinal Chemistry
IS - 17
ER -