Trypanothione reductase is a flavoenzyme unique to trypanosomatid parasites. Here we show that unsaturated Mannich bases irreversibly inactivate trypanothione reductase from Trypanosoma cruzi, the causative agent of Chagas' disease. The inhibitory potency of the compounds strongly increased upon storage of the DMSO stock solutions. HPLC, NMR, and mass spectrometry data of potential intermediates revealed a divinyl ketone as the active compound inactivating the enzyme. ESI- and MALDI-TOF mass spectrometry of trypanothione reductase modified by the Mannich base or the divinyl ketone showed specific alkylation of the active site Cys52 by a 5-(2'chlorophenyl)-3-oxo-4-pentenyl substituent. The reaction mechanism and the site of alkylation differ from those in Plasmodium falciparum thioredoxin reductase where the C-terminal redox active dithiol is modified. After deamination, unsaturated Mannich bases are highly reactive in polycondensation with trypanothione. Interaction of these compounds with both trypanothione and trypanothione reductase could account for their potent trypanocidal effect against Trypanosoma brucei.
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http://dx.doi.org/10.1021/jm0504860 | DOI Listing |
Molecules
January 2025
Department of Biochemistry and Organic Chemistry, Institute of Chemistry, São Paulo State University (UNESP), Araraquara 14800-060, SP, Brazil.
Leishmaniasis is a neglected tropical disease caused by a protozoan of the genus Leishmania, which has visceral and cutaneous forms. The symptoms of leishmaniasis include high fever and weakness, and the cutaneous infection also causes lesions under the skin. The drugs used to treat leishmaniasis have become less effective due to the resistance mechanisms of the protozoa.
View Article and Find Full Text PDFChem Biodivers
January 2025
Department of Pharmaceutical Sciences, Postgraduate Program in Pharmaceutical Sciences, Federal University of Pernambuco/UFPE, Recife, Brazil.
Leishmaniasis is a neglected disease caused by parasites of the genus Leishmania sp. that causes approximately 1 million cases and 650,000 deaths annually worldwide. Its treatment has several limitations mainly due to high toxicity and clinical resistance, and the search for alternatives is highly desirable.
View Article and Find Full Text PDFIn Silico Pharmacol
December 2024
Laboratory of Cell and Molecular Biology, Department of Botany, Centre of Advanced Study, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019 India.
Visceral Leishmaniasis, caused by is the second most deadly parasitic disease, causing over 65,000 deaths annually. Synthetic drugs available in the market, to combat this disease, have numerous side effects. In this backdrop, we aim to find safer antileishmanial alternatives with minimal side effects from mushrooms, which harbour various secondary metabolites with promising efficacy.
View Article and Find Full Text PDFChem Biodivers
December 2024
Departamento de Ingeniería Agrícola y Alimentos, Facultad de Ciencias Agrarias, Universidad Nacional de Colombia-Sede Medellín, Medellín, Antioquia, Colombia.
Coumarin-chalcone hybrids are promising compounds that could be used as lead structures in the fight against parasitic diseases. In this work, 16 hybrids of coumarin-chalcone (3-cinnamoyl-2H-chromen-2-ones) were synthesized, and their in vitro biological activity was evaluated against intracellular amastigotes of Leishmania braziliensis and Trypanosoma cruzi, as well as their cytotoxicity in the U-937 cell line. Compounds (E)-3-(3-(3-ethoxy-4-hydroxyphenyl)acryloyl)-7-methoxy-2H-chromen-2-one (H) and (E)-7-(diethylamino)-3-(4-(methoxyphenyl)acryloyl)-2H-chromen-2-one (H) showed the highest antileishmanial activity with EC values of 18.
View Article and Find Full Text PDFBioorg Chem
January 2025
School of Pharmacy, Federal University of Ouro Preto, 35402-163 Ouro Preto, MG, Brazil. Electronic address:
Chagas disease (CD) is a life-threatening illness caused by the protozoan Trypanosoma cruzi and there are only two drugs currently available for pharmacotherapy of this neglected infection (benznidazole and nifurtimox). Their limited efficacy in chronic phase of the disease, problems of toxicity and the growing resistance by the protozoan are directly associated to high rates of drug discontinuation by the patients. In the context of the search for new trypanocidal drug candidates, our group has been working with the chemical manipulation of eugenol to obtain new agents active against T.
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