Probing the aurone scaffold against Plasmodium falciparum: Design, synthesis and antimalarial activity

• Published in: European journal of medicinal chemistry Vol. 80; pp. 523 - 534
• Main Authors: Carrasco, Marta P., Newton, Ana S., Gonçalves, Lídia, Góis, Ana, Machado, Marta, Gut, Jiri, Nogueira, Fátima, Hänscheid, Thomas, Guedes, Rita C., dos Santos, Daniel J.V.A., Rosenthal, Philip J., Moreira, Rui
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 10-06-2014; Elsevier
• Subjects: Antimalarials - chemistry; Antimalarials - pharmacology; Antimalarials - toxicity; Aurones; Benzofurans - chemistry; Benzofurans - pharmacology; Benzofurans - toxicity; Cell Line, Tumor; Cell Survival - drug effects; Cross-coupling reactions; Drug Design; Drug Interactions; Humans; Inhibitory Concentration 50; Malaria; Plasmodium falciparum; Plasmodium falciparum - cytology; Plasmodium falciparum - drug effects; Vacuoles - drug effects; Plasmodium falciparum; Malaria; Cross-coupling reactions; Aurones
• ISSN: 0223-5234; 1768-3254
• DOI: 10.1016/j.ejmech.2014.04.076

A library comprising 44 diversely substituted aurones derivatives was synthesized by straightforward aldol condensation reactions of benzofuranones and the appropriately substituted benzaldehydes. Microwave enhanced synthesis using palladium catalyzed protocols was introduced as a powerful strategy for extending the chemical space around the aurone scaffold. Additionally, Mannich-base derivatives, containing a 7-aminomethyl-6-hydroxy substitution pattern at ring A, were also prepared. Screening against the chloroquine resistant Plasmodium falciparum W2 strain identified novel aurones with IC50 values in the low micromolar range. The most potent compounds contained a basic moiety, with the ability to accumulate in acidic digestive vacuole of the malaria parasite. However, none of those aurones revealed significant activity against hemozoin formation and falcipain-2, two validated targets expressed during the blood stage of P. falciparum infection and functional in digestive vacuole of the parasite. Overall, this study highlight (i) the usefulness of aurones as platforms for synthetic procedures using palladium catalyzed protocols to rapidly deliver lead compounds for further optimization and (ii) the potential of novel aurone derivatives as promising antimalarial compounds.
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•Novel synthetic aurone derivatives synthesized and screened against Plasmodium falciparum.•Aurones are a useful platform for synthetic procedures using palladium catalyzed protocols to rapidly deliver lead compounds.•Compound 7b showed antimalarial activity in low micromolar concentration.•Report shows the potential of this scaffold for antiplasmodial lead optimization.