Potential Antimalarials. XXII. Some 2,4-Diamino-5-(3- and 4-trifluoromethylphenyl and 3,4-methylenedioxyphenyl)pyrimidines

1996 ◽  
Vol 49 (6) ◽  
pp. 647 ◽  
Author(s):  
GB Barlin ◽  
B Kotecka ◽  
KH Rieckmann
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Activity ◽  
Drug Resistant

A series of 10 pyrimethamine analogues containing 3'- and 4'-trifluoromethyl and 3',4'-methylenedioxy groups has been prepared and tested for in vitro antimalarial activity against the FC-27 and K-1isolates of Plasmodium falciparum. Several of these compounds were almost as active as pyrimethamine against the drug-sensitive FC-27 isolate, and like pyrimethamine , they were much less active against the drug-resistant K-1 isolate. The 4'-trifluoromethyl compunds, however, showed much smaller differences.

Hybrid molecules with potential in vitro antiplasmodial and in vivo antimalarial activity against drug‐resistant Plasmodium falciparum

2019 ◽  
Vol 40 (3) ◽  
pp. 931-971 ◽  
Author(s):  
Lian‐Shun Feng ◽  
Zhi Xu ◽  
Le Chang ◽  
Chuan Li ◽  
Xiao‐Fei Yan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Activity ◽  
Drug Resistant ◽  
Hybrid Molecules

scholarly journals Potent and Selective Activity of a Combination of Thymidine and 1843U89, a Folate-Based Thymidylate Synthase Inhibitor, against Plasmodium falciparum

2000 ◽  
Vol 44 (4) ◽  
pp. 1047-1050 ◽  
Author(s):  
Lei Jiang ◽  
Pei-Chieh Lee ◽  
John White ◽  
Pradipsinh K. Rathod
Keyword(s):  
Plasmodium Falciparum ◽  
Thymidylate Synthase ◽  
Mammalian Cells ◽  
De Novo ◽  
Antimalarial Activity ◽  
Malarial Parasite ◽  
Drug Resistant ◽  
Additional Tool ◽  
Synthase Inhibitor

ABSTRACT Unlike mammalian cells, malarial parasites are completely dependent on the de novo pyrimidine pathway and lack the enzymes to salvage preformed pyrimidines. In the present study, first, it is shown that 1843U89, even without polyglutamylation, is a potent folate-based inhibitor of purified malarial parasite thymidylate synthase. The binding was noncompetitive with respect to methylenetetrahydrofolate, and 1843U89 had a Ki of 1 nM. The compound also had potent antimalarial activity in vitro. Plasmodium falciparum cells in culture were inhibited by 1843U89, with a 50% inhibitory concentration of about 70 nM. The compound was effective against drug-sensitive as well as drug-resistant clones ofP. falciparum. As predicted by the biochemistry of the parasite, the potent inhibition of parasite proliferation by 1843U89 could not be reversed with 10 μM thymidine. In contrast, in the presence of 10 μM thymidine, mammalian cells were unaffected by 1843U89 even at concentrations as high as 0.1 mM, thus offering a selectivity window of more than 1,000-fold. On this basis, folate-based thymidylate synthase inhibitors may represent a powerful additional tool that can be used to combat drug-resistant malaria.

scholarly journals Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro

Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1250-1255 ◽  
Author(s):  
S Whitehead ◽  
TE Peto
Keyword(s):  
Plasmodium Falciparum ◽  
Growth Inhibition ◽  
Antimalarial Activity ◽  
Clinical Malaria ◽  
Inhibitory Effect ◽  
Parasite Development ◽  
And Control ◽  
Speed Of Onset

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.

scholarly journals In vitro activities of novel catecholate siderophores against Plasmodium falciparum.

1996 ◽  
Vol 40 (9) ◽  
pp. 2094-2098 ◽  
Author(s):  
B Pradines ◽  
F Ramiandrasoa ◽  
L K Basco ◽  
L Bricard ◽  
G Kunesch ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Mechanism Of Action ◽  
Ribonucleotide Reductase ◽  
Antimalarial Activity ◽  
Iron Chelators ◽  
Resistant Clone ◽  
Iron Deprivation ◽  
Level Of Activity ◽  
Susceptible Clone

The activities of novel iron chelators, alone and in combination with chloroquine, quinine, or artemether, were evaluated in vitro against susceptible and resistant clones of Plasmodium falciparum with a semimicroassay system. N4-nonyl,N1,N8-bis(2,3-dihydroxybenzoyl) spermidine hydrobromide (compound 7) demonstrated the highest level of activity: 170 nM against a chloroquine-susceptible clone and 1 microM against a chloroquine-resistant clone (50% inhibitory concentrations). Compounds 6, 8, and 10 showed antimalarial activity with 50% inhibitory concentrations of about 1 microM. Compound 7 had no effect on the activities of chloroquine, quinine, and artemether against either clone, and compound 8 did not enhance the schizontocidal action of either chloroquine or quinine against the chloroquine-resistant clone. The incubation of compound 7 with FeCI3 suppressed or decreased the in vitro antimalarial activity of compound 7, while no effect was observed with incubation of compound 7 with CuSO4 and ZnSO4. These results suggest that iron deprivation may be the main mechanism of action of compound 7 against the malarial parasites. Chelator compounds 7 and 8 primarily affected trophozoite stages, probably by influencing the activity of ribonucleotide reductase, and thus inhibiting DNA synthesis.

scholarly journals Synthesis and in Vitro Antimalarial Activity of Alkyl Esters Gallate as a Growth Inhibitors of Plasmodium Falciparum

2018 ◽  
Vol 34 (2) ◽  
pp. 655-662 ◽  
Author(s):  
Ade Arsianti ◽  
Hendry Astuti ◽  
Fadilah Fadilah ◽  
Daniel Martin Simadibrata ◽  
Zoya Marie Adyasa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Activity ◽  
Growth Inhibitors ◽  
Alkyl Esters

scholarly journals Synthesis, antimalarial activity evaluation and molecular docking studies of some novel dispiro-1,2,4,5-tetraoxanes

2015 ◽  
Vol 10 (4) ◽  
pp. 917 ◽  
Author(s):  
Mukesh Kumar Kumawat ◽  
Dipak Chetia
Keyword(s):  
Plasmodium Falciparum ◽  
Molecular Docking ◽  
Resistant Strain ◽  
Antimalarial Activity ◽  
Binding Pocket ◽  
Docking Studies ◽  
Spectroscopic Techniques ◽  
Molecular Docking Studies ◽  
Activity Screening

<p class="Abstract">Seven novel dispiro-1,2,4,5-tetraoxane derivatives were synthesized and characterized by a number of analytical and spectroscopic techniques. The molecules were subsequently screened for in vitro antimalarial activity against chloroquine resistant strain of <em>Plasmodium falciparum</em> (RKL-9). At antimalarial activity screening, two compounds, namely 5d (MIC = 15.6 µg/mL or 64.5 µM) and 5f (MIC = 15.6 µg/mL or 54.6 µM) were found to be about 1.5 times more potent against chloroquine resistant strain-RKL-9 compared to chloroquine (MIC = 25.0 µg/mL or 78.3 µM). Molecular docking studies of potent ligands were also performed in cysteine protease binding pocket residues of falcipain-2 as a target protein.</p><p> </p>

scholarly journals Overexpression of Plasmodium falciparum M1 Aminopeptidase Promotes an Increase in Intracellular Proteolysis and Modifies the Asexual Erythrocytic Cycle Development

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1452
Author(s):  
Carolina C. Hoff ◽  
Mauro F. Azevedo ◽  
Adriana B. Thurler ◽  
Sarah El Chamy Maluf ◽  
Pollyana M. S. Melo ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Activity ◽  
Fold Increase ◽  
Cysteine Proteases ◽  
Aminopeptidase Activity ◽  
Lower Sensitivity ◽  
Wild Type ◽  
Erythrocytic Cycle ◽  
Transgenic Parasite

Plasmodium falciparum, the most virulent of the human malaria parasite, is responsible for high mortality rates worldwide. We studied the M1 alanyl-aminopeptidase of this protozoan (PfA-M1), which is involved in the final stages of hemoglobin cleavage, an essential process for parasite survival. Aiming to help in the rational development of drugs against this target, we developed a new strain of P. falciparum overexpressing PfA-M1 without the signal peptide (overPfA-M1). The overPfA-M1 parasites showed a 2.5-fold increase in proteolytic activity toward the fluorogenic substrate alanyl-7-amido-4-methylcoumarin, in relation to the wild-type group. Inhibition studies showed that overPfA-M1 presented a lower sensitivity against the metalloaminopeptidase inhibitor bestatin and to other recombinant PfA-M1 inhibitors, in comparison with the wild-type strain, indicating that PfA-M1 is a target for the in vitro antimalarial activity of these compounds. Moreover, overPfA-M1 parasites present a decreased in vitro growth, showing a reduced number of merozoites per schizont, and also a decrease in the iRBC area occupied by the parasite in trophozoite and schizont forms when compared to the controls. Interestingly, the transgenic parasite displays an increase in the aminopeptidase activity toward Met-, Ala-, Leu- and Arg-7-amido-4-methylcoumarin. We also investigated the potential role of calmodulin and cysteine proteases in PfA-M1 activity. Taken together, our data show that the overexpression of PfA-M1 in the parasite cytosol can be a suitable tool for the screening of antimalarials in specific high-throughput assays and may be used for the identification of intracellular molecular partners that modulate their activity in P. falciparum.

scholarly journals Antimalarial activity of betulinic acid and derivatives in vitro against Plasmodium falciparum and in vivo in P. berghei-infected mice

2009 ◽  
Vol 105 (1) ◽  
pp. 275-279 ◽  
Author(s):  
Matheus Santos de Sá ◽  
José Fernando Oliveira Costa ◽  
Antoniana Ursine Krettli ◽  
Mariano Gustavo Zalis ◽  
Gabriela Lemos de Azevedo Maia ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Betulinic Acid ◽  
Antimalarial Activity

Total synthesis and antimalarial activity of mortiamides A–D

2019 ◽  
Vol 55 (52) ◽  
pp. 7434-7437 ◽  
Author(s):  
Christopher Bérubé ◽  
Dominic Gagnon ◽  
Alexandre Borgia ◽  
Dave Richard ◽  
Normand Voyer
Keyword(s):  
Plasmodium Falciparum ◽  
Total Synthesis ◽  
Resistant Strain ◽  
Antimalarial Activity ◽  
Drug Resistant

This work describes the first total synthesis of mortiamides and their anti-malarial activity against a multi-drug resistant strain of Plasmodium falciparum.

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