Design and synthesis of potent inhibitors of the malaria aspartyl proteases plasmepsin I and II. Use of solid-phase synthesis to explore novel statine motifs.
Picomolar to low nanomolar inhibitors of the two aspartic proteases plasmepsin (Plm) I and II, from the malaria parasite Plasmodium falciparum, have been identified from sets of libraries containing novel statine-like templates modified at the amino and carboxy terminus. The syntheses of the novel statine templates were carried out in solution phase using efficient synthetic routes and resulting in excellent stereochemical control. The most promising statine template was attached to solid support and diversified by use of parallel synthesis. The products were evaluated for their Plm I and II inhibitory activity as well as their selectivity over cathepsin D. Selected inhibitors were, in addition, evaluated for their inhibition of parasite growth in cultured infected human red blood cells. The most potent inhibitor in this report, compound 16, displays Ki values of 0.5 and 2.2 nM for Plm I and II, respectively. Inhibitor 16 is also effective in attenuating parasite growth in red blood cells showing 51% inhibition at a concentration of 5 microM. Several inhibitors have been identified that exhibit Ki values between 0.5 and 74 nM for both Plm I and II. Some of these inhibitors also show excellent selectivity vs cathepsin D.
Johansson
Per-Ola
PO
Department of Chemistry, Linköping University, S-581 83 Linköping, Sweden.
Chen
Yantao
Y
Belfrage
Anna Karin
AK
Blackman
Michael J
MJ
Kvarnström
Ingemar
I
Jansson
Katarina
K
Vrang
Lotta
L
Hamelink
Elizabeth
E
Hallberg
Anders
A
Rosenquist
Asa
A
Samuelsson
Bertil
B
D000181:Acrylonitrile / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D000962:Antimalarials / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D002402:Cathepsin D / Q000037:antagonists & inhibitors / Q000737:chemistry; D020650:Combinatorial Chemistry Techniques; D004151:Dipeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008958:Models, Molecular; D018716:Molecular Mimicry; D010963:Plasmodium falciparum / Q000187:drug effects; D015800:Protozoan Proteins; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology
C487574:2-(1H-benzimidazol-2-yl)-3-(5-nitrothiophen-2-yl)acrylonitrile; D000962:Antimalarials; D004151:Dipeptides; D015800:Protozoan Proteins; D013876:Thiophenes; D016282:Aspartic Acid Endopeptidases; C089643:plasmepsin; C100637:plasmepsin II; D002402:Cathepsin D; D000181:Acrylonitrile