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1.
Bioorg Chem ; 146: 107249, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38493638

RESUMO

One of the deadliest infectious diseases, malaria, still has a significant impact on global morbidity and mortality. Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) catalyzes the fourth step in de novo pyrimidine nucleotide biosynthesis and has been clinically validated as an innovative and promising target for the development of novel targeted antimalarial drugs. PfDHODH inhibitors have the potential to significantly slow down parasite growth at the blood and liver stages. Several PfDHODH inhibitors based on various scaffolds have been explored over the past two decades. Among them, triazolopyrimidines, isoxazolopyrimidines, and pyrrole-based derivatives known as DSM compounds showed tremendous potential as novel antimalarial agents, and one of the triazolopyrimidine-based compounds (DSM265) was able to reach phase IIa clinical trials. DSM compounds were synthesized as PfDHODH inhibitors with various substitutions based on structure-guided medicinal chemistry approaches and further optimised as well. For the first time, this review provides an overview of all the synthetic approaches used for the synthesis, alternative synthetic routes, and novel strategies involving various catalysts and chemical reagents that have been used to synthesize DSM compounds. We have also summarized SAR study of all these PfDHODH inhibitors. In an attempt to assist readers, scientists, and researchers involved in the development of new PfDHODH inhibitors as antimalarials, this review provides accessibility of all synthetic techniques and SAR studies of the most promising triazolopyrimidines, isoxazolopyrimidines, and pyrrole-based PfDHODH inhibitors.


Assuntos
Antimaláricos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Antimaláricos/química , Plasmodium falciparum , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Pirróis/farmacologia , Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química
2.
Eur J Med Chem ; 267: 116163, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38290351

RESUMO

The World Health Organization (WHO) estimated that there were 247 million malaria cases in 2021 worldwide, representing an increase in 2 million cases compared to 2020. The urgent need for the development of new antimalarials is underscored by specific criteria, including the requirement of new modes of action that avoid cross-drug resistance, the ability to provide single-dose cures, and efficacy against both assexual and sexual blood stages. Motivated by the promising results obtained from our research group with [1,2,4]triazolo[1,5-a]pyrimidine and pyrazolo[1,5-a]pyrimidine derivatives, we selected these molecular scaffolds as the foundation for designing two new series of piperaquine analogs as potential antimalarial candidates. The initial series of hybrids was designed by substituting one quinolinic ring of piperaquine with the 1,2,4-triazolo[1,5-a]pyrimidine or pyrazolo[1,5-a]pyrimidine nucleus. To connect the heterocyclic systems, spacers with 3, 4, or 7 methylene carbons were introduced at the 4 position of the quinoline. In the second series, we used piperazine as a spacer to link the 1,2,4-triazolo[1,5-a]pyrimidine or pyrazolo[1,5-a]pyrimidine group to the quinoline core, effectively merging both pharmacophoric groups via a rigid spacer. Our research efforts yielded promising compounds characterized by low cytotoxicity and selectivity indices exceeding 1570. These compounds displayed potent in vitro inhibitory activity in the low nanomolar range against the erythrocytic form of the parasite, encompassing both susceptible and resistant strains. Notably, these compounds did not show cross-resistance with either chloroquine or established P. falciparum inhibitors. Even though they share a pyrazolo- or triazolo-pyrimidine core, enzymatic inhibition assays revealed that these compounds had minimal inhibitory effects on PfDHODH, indicating a distinct mode of action unrelated to targeting this enzyme. We further assessed the compounds' potential to interfere with gametocyte and ookinete infectivity using mature P. falciparum gametocytes cultured in vitro. Four compounds demonstrated significant gametocyte inhibition ranging from 58 % to 86 %, suggesting potential transmission blocking activity. Finally, we evaluated the druggability of these new compounds using in silico methods, and the results indicated that these analogs had favorable physicochemical and ADME (absorption, distribution, metabolism, and excretion) properties. In summary, our research has successfully identified and characterized new piperaquine analogs based on [1,2,4]triazolo[1,5-a]pyrimidine and pyrazolo[1,5-a]pyrimidine scaffolds and has demonstrated their potential as promising candidates for the development of antimalarial drugs with distinct mechanisms of action, considerable selectivity, and P. falciparum transmission blocking activity.


Assuntos
Antimaláricos , Malária Falciparum , Piperazinas , Quinolinas , Humanos , Antimaláricos/farmacologia , Antimaláricos/química , Plasmodium falciparum , Quinolinas/química , Malária Falciparum/tratamento farmacológico , Pirimidinas/química
3.
Expert Opin Ther Pat ; 33(9): 579-596, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37942637

RESUMO

INTRODUCTION: Pyrimidine nucleotides are essential for the parasite's growth and replication. Parasites have only a de novo pathway for the biosynthesis of pyrimidine nucleotides. Dihydroorotate dehydrogenase (DHODH) enzyme is involved in the rate-limiting step of the pyrimidine biosynthesis pathway. DHODH is a biochemical target for the discovery of new antimalarial agents. AREA COVERED: This review discussed the development of patented PfDHODH inhibitors published between 2007 and 2023 along with their chemical structures and activities. EXPERT OPINION: PfDHODH enzyme is involved in the rate-limiting fourth step of the pyrimidine biosynthesis pathway. Thus, inhibition of PfDHODH using species-selective inhibitors has drawn much attention for treating malaria because they inhibit parasite growth without affecting normal human functions. Looking at the current scenario of antimalarial drug resistance with most of the available antimalarial drugs, there is a huge need for targeted newer agents. Newer agents with unique mechanisms of action may be devoid of drug toxicity, adverse effects, and the ability of parasites to quickly gain resistance, and PfDHODH inhibitors can be those newer agents. Many PfDHODH inhibitors were patented in the past, and the dependency of Plasmodium on de novo pyrimidine provided a new approach for the development of novel antimalarial agents.


Assuntos
Antimaláricos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Humanos , Di-Hidro-Orotato Desidrogenase , Antimaláricos/farmacologia , Antimaláricos/química , Plasmodium falciparum/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Patentes como Assunto , Pirimidinas/farmacologia , Inibidores Enzimáticos/farmacologia , Nucleotídeos de Pirimidina/farmacologia
4.
Acta Parasitol ; 68(4): 807-819, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37821729

RESUMO

PURPOSE: Major human parasitic protozoans, such as Plasmodium falciparum and Trypanosoma brucei, cause malaria and trypanosomiasis also known as sleeping sickness. In anti-parasitic drug discovery research, trypanothione reductase (TryR) and P. falciparum dihydroorotate dehydrogenase (Pf-DHODH) enzymes are key drug targets in T. brucei and P. falciparum, respectively. The possibility of co-infection of single host by T. brucei and P. falciparum is because both parasites exist in sub-Saharan Africa and the problem of parasite drug resistance necessitates the discovery of new scaffolds, which are strange to the organisms causing these infectious diseases-new scaffolds may help overcome established resistance mechanisms of the organisms. METHOD: In this study, N,N'-bis[2-(5-bromo-7-azabenzimidazol-1-yl)-2-oxoethyl]ethylene-1,3-diamine and its cyclohexyl-1,2-diamine analogue were explored for their inhibitory potential against TryR and Pf-DHODH by engaging density functional study, molecular dynamic simulations, drug-likeness, in silico and in vitro studies RESULTS/CONCLUSION: Results obtained indicated excellent binding potential of the ligands to the receptors and good ADMET (adsorption, desorption, metabolism, excretion, and toxicity) properties.


Assuntos
Inibidores Enzimáticos , Plasmodium falciparum , Trypanosoma , Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos/farmacologia , Etilenos , Plasmodium falciparum/efeitos dos fármacos , Trypanosoma/efeitos dos fármacos
5.
Future Med Chem ; 15(14): 1295-1321, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37551689

RESUMO

Malaria is a severe human disease and a global health problem because of drug-resistant strains. Drugs reported to prevent the growth of Plasmodium parasites target various phases of the parasites' life cycle. Antimalarial drugs can inhibit key enzymes that are responsible for the cellular growth and development of parasites. Plasmodium falciparum dihydroorotate dehydrogenase is one such enzyme that is necessary for de novo pyrimidine biosynthesis. This review focuses on various medicinal chemistry approaches used for the discovery and identification of selective P. falciparum dihydroorotate dehydrogenase inhibitors as antimalarial agents. This comprehensive review discusses recent advances in the selective therapeutic activity of distinct chemical classes of compounds as P. falciparum dihydroorotate dehydrogenase inhibitors and antimalarial drugs.

6.
Comput Biol Chem ; 101: 107787, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36401950

RESUMO

Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) is a known drug target for the development of antimalarial agents. Herein, we presented integrated structure-guided computational strategies for the design of novel quinolizin-4-ones as PfDHODH inhibitors. PROCHECK and ERRAT analysis were performed for the validation of co-crystal structures of PfDHODH enzyme bound to the inhibitors available on PDB. Based on the results, PDB ID: 6i55 was selected for further structure-guided in silico studies. Five featured-based pharmacophore model (AADRR) was generated, and validated using GH scoring (0.74) and ROC analysis (0.94). Validated structure-based model was further used as a 3D search query to screen the ZINC database. Retrieved database compounds ZINC00386658, ZINC08439293, and ZINC09089086 were found in agreement with query features based on their highest fitness scores. HTVS, SP and XP docking studies with these retrieved hits demonstrated important interactions (His185. Arg265) with PfDHODH. Mapping of features of the pharmacophore model on these retrieved hits along with the role played by scaffolds and functional groups in docking study helped in the selection of quinolizin-4-one as a main scaffold and different functional groups for the design of novel compounds as PfDHODH inhibitors. In silico ADMET prediction study suggested that designed quinolizin-4-ones are "drug-like" candidates and can be synthesised without too many difficulties. In docking study of newly designed compounds, 8d exhibited the highest docking score of - 12.78 kcal/mol and formed important polar interactions (His185. Arg265) with the PfDHODH. PfDHODH-8d complex showed stable RMSD between 2.5 Å and 3 Å during 100 ns MD simulation study. The RMSD, RMSF and RoG analysis of the PfDHODH-8d complex indicated the absolute stability of the complex. Overall, combined in silico study identified quinolizin-4-ones as selective PfDHODH inhibitors.


Assuntos
Antimaláricos , Plasmodium falciparum , Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos/farmacologia , Antimaláricos/farmacologia , Simulação por Computador
7.
Egypt J Med Hum Genet ; 23(1): 119, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37521844

RESUMO

Background: The processes of drug development and validation are too expensive to be subjected to experimental trial and errors. Hence, the use of the insilico approach becomes imperative. To this effect, the drug-likeness and pharmacokinetic properties of the ten (10) previously designed derivatives of 2-anilino 4-amino substituted quinazolines were carried out. Their predicted ligand binding interactions were also carried out by docking them against the Plasmodium falciparum dihydroorotate dehydrogenase (Pf-DHODH) protein target, and the stability of the complex was determined through dynamic simulations. The drug-likeness and pharmacokinetic characteristics were estimated using the online SwissADME software, while the Molegro Virtual Docker (MVD) software was used for molecular docking. And the dynamic simulation was performed for the duration of 100 ns to verify the stability of the docked complex, with the aid of a Schrödinger program, Desmond. Results: The designed derivatives were all found to pass the Lipinski test of drug likeness, while the pharmacokinetic studies result that the skin permeability and molar refractivity values of the derivatives are both within the limits. In addition, except for derivative C-01, most of the derivatives have strong gastrointestinal absorptions and lack Pgp substrate. Furthermore, no derivative inhibited CYP1A2, CYP2C9, or CYP2C19. The docking studies show the better binding affinities between the ligands and Pf-DHODH than those between the atovaquone or chloroquine standards. The derivative C-02, {5-((6,7-dimethoxy-4-((3-nitrobenzyl)amino)quinazolin-2-yl)amino)-2-fluorobenzaldehyde} was found to be the most stable derivative, with a re-rank docking score of - 173.528 kcal/mol and interaction energy of - 225.112 kcal/mol. The dynamic simulation analysis shows that the derivative C-02 forms a stable complex with the protein target over the simulation time. Conclusions: The ability of these ligands to form hydrogen bonds, as well as various other interactions, was cited as a factor responsible for their better binding affinity. These findings could aid further the development of enhanced antimalarial drugs.

8.
Curr Comput Aided Drug Des ; 17(3): 480-491, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32459610

RESUMO

BACKGROUND: Leflunomide (LFM) and its active metabolite, teriflunomide (TFM), have drawn a lot of attention for their anticancer activities, treatment of rheumatoid arthritis and malaria due to their capability to inhibit dihydroorotate dehydrogenase (DHODH) and Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) enzyme. In this investigation, the strength of intramolecular hydrogen bond (IHB) in five analogs of TFM (ATFM) was analyzed employing density functional theory (DFT) using B3LYP/6-311++G (d, p) level and molecular orbital analysis in the gas phase and water solution. A detailed electronic structure study was performed using the quantum theory of atoms in molecules (QTAIM) and the hydrogen bond energies (EHB) of stable conformer obtained in the range of 76-97 kJ/mol, as a medium hydrogen bond. The effect of substitution on the IHB nature was studied by natural bond orbital analysis (NBO). 1H NMR calculations showed an upward trend in the proton chemical shift of the enolic proton in the chelated ring (14.5 to 15.7ppm) by increasing the IHB strength. All the calculations confirmed the strongest IHB in 5-F-ATFM and the weakest IHB in 2-FATFM. Molecular orbital analysis, including the HOMO-LUMO gap and chemical hardness, was performed to compare the reactivity of inhibitors. Finally, molecular docking analysis was carried out to identify the potency of inhibition of these compounds against PfDHODH enzyme. TFM acts as an inhibitor of dihydroorotate dehydrogenase (DHODH) and Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) enzyme. Leflunomide and its active metabolite teriflunomide have been identified as drugs for treatment of some diseases, such as multiple sclerosis (MS), rheumatoid arthritis (RA), malaria, and cancer. Hydrogen bonds play a key role in the interaction between drugs and enzymes. OBJECTIVES: The aim of the present work is to investigate the effect of the strength of intramolecular hydrogen bonds (IHBs) in the active metabolite analogs of leflunomide or analogs of teriflunomide (ATFMs) and study the interaction of these inhibitors against the PfDHODH enzyme using quantum mechanical methods. METHODS: At first, intramolecular hydrogen bonds in five ATFMs were evaluated by the DFT method, quantum theory of atoms in molecules (QTAIM), nuclear magnetic resonance (NMR), natural bond orbital (NBO), and molecular orbital (MO) analyses. Then, the interaction of these inhibitors against the PfDHODH enzyme were compared using molecular docking study. RESULTS: All the computed results confirm the following trend in the intramolecular hydrogen bond strength in five mono-halo-substituted 2-cyano-3-hydroxy-N-phenylbut-2-enamide (ATFM): 5-FATFM> 4-Br-ATFM ≈ 3-Br-ATFM>3-Cl-ATFM>TFM-Z>2-F-ATFM which is in agreement with QTAIM, NMR, and NBO results. Docking results show that 5-F-ATFM (EHB=97kJ/mol) has the minimum MolDock score due to its considerable IHB strength. CONCLUSION: For strong IHBs (EHB>100kJ/mol), C=O and O-H group are involved in the intramolecular interactions and do not contribute to the external interactions. Also, the docking study revealed maximum binding energy between TFM-Z and PfDHODH enzyme.


Assuntos
Crotonatos/farmacologia , Di-Hidro-Orotato Desidrogenase/antagonistas & inibidores , Hidroxibutiratos/farmacologia , Leflunomida/farmacologia , Nitrilas/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Toluidinas/farmacologia , Crotonatos/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Ligação de Hidrogênio , Hidroxibutiratos/química , Leflunomida/análogos & derivados , Leflunomida/química , Modelos Moleculares , Simulação de Acoplamento Molecular , Nitrilas/química , Plasmodium falciparum/enzimologia , Teoria Quântica , Toluidinas/química
9.
Eur J Med Chem ; 209: 112941, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33158577

RESUMO

In this work, we designed and synthesized 35 new triazolopyrimidine, pyrazolopyrimidine and quinoline derivatives as P. falciparum inhibitors (3D7 strain). Thirty compounds exhibited anti-P. falciparum activity, with IC50 values ranging from 0.030 to 9.1 µM. The [1,2,4]triazolo[1,5-a]pyrimidine derivatives were more potent than the pyrazolo[1,5-a]pyrimidine and quinoline analogues. Compounds 20, 21, 23 and 24 were the most potent inhibitors, with IC50 values in the range of 0.030-0.086 µM and were equipotent to chloroquine. In addition, the compounds were selective, showing no cytotoxic activity against the human hepatoma cell line HepG2. All [1,2,4]triazolo[1,5-a]pyrimidine derivatives inhibited PfDHODH activity in the low micromolar to low nanomolar range (IC50 values of 0.08-1.3 µM) and did not show significant inhibition against the HsDHODH homologue (0-30% at 50 µM). Molecular docking studies indicated the binding mode of [1,2,4]triazolo[1,5-a]pyrimidine derivatives to PfDHODH, and the highest interaction affinities for the PfDHODH enzyme were in agreement with the in vitro experimental evaluation. Thus, the most active compounds against P. falciparum parasites 20 (R = CF3, R1 = F; IC50 = 0.086 µM), 21 (R = CF3; R1 = CH3; IC50 = 0.032 µM), 23, (R = CF3, R1 = CF3; IC50 = 0.030 µM) and 24 (R = CF3, 2-naphthyl; IC50 = 0.050 µM) and the most active inhibitor against PfDHODH 19 (R = CF3, R1 = Cl; IC50 = 0.08 µM - PfDHODH) stood out as new lead compounds for antimalarial drug discovery. Their potent in vitro activity against P. falciparum and the selective inhibition of the PfDHODH enzyme strongly suggest that this is the mechanism of action underlying this series of new [1,2,4]triazolo[1,5-a]pyrimidine derivatives.


Assuntos
Antimaláricos/síntese química , Inibidores Enzimáticos/química , Malária Falciparum/tratamento farmacológico , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Pirimidinas/síntese química , Quinolinas/síntese química , Triazóis/síntese química , Antimaláricos/química , Antimaláricos/farmacologia , Cloroquina/farmacologia , Di-Hidro-Orotato Desidrogenase , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Células Hep G2 , Humanos , Simulação de Acoplamento Molecular , Plasmodium falciparum/efeitos dos fármacos , Ligação Proteica , Pirimidinas/farmacologia , Quinolinas/farmacologia , Relação Estrutura-Atividade , Triazóis/farmacologia
10.
Front Mol Biosci ; 7: 105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32582763

RESUMO

The research explores the synthesis of a series of novel hybrid quinazolin-2,4-dione analogs bearing acetyl/amide bridged-nitrogen heterocyclic moieties such as azetidinone, pyrrole, oxazole, oxadiazole, thiazole, pyrazole, and thiazolidine scaffolds 2-16. The newly synthesized compounds were structurally confirmed by means of IR, 1H-NMR, 13C-NMR, MS and elemental analysis. In addition, an in silico molecular docking analysis of new compounds and standard drug (Chloroquine) has been performed to analyze the binding modes of interaction to the putative active site of Plasmodium falciparum Dihydroorotate dehydrogenase (pfDHODH). Aiming to search for potentially better antimalarials, a modern approach has been undertaken to identify new quinazolin-2,4-dione derivatives targeting pfDHODH. The identification of antimalarial activity of the newly synthesized compounds by using experimental techniques is expensive and requires extensive pains and labor. The compound 11 showed the highest binding affinity against pfDHODH. Moreover, the electrostatic potential (ESP) of the docked molecules was also calculated. Further, the pharmacokinetic properties (ADMET) of the prepared compounds were predicted through in silico technique.

11.
Molecules ; 24(22)2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31766184

RESUMO

Based on medicinal chemistry tools, new compounds for malaria treatment were designed. The scaffolds of the drugs used to treat malaria, such as chloroquine, primaquine, amodiaquine, mefloquine and sulfadoxine, were used as inspiration. We demonstrated the importance of quinoline and non-quinoline derivatives in vitro with activity against the W2 chloroquine-resistant (CQR) Plasmodium falciparum clone strain and in vivo against Plasmodium berghei-infected mouse model. Among the quinoline derivatives, new hybrids between chloroquine and sulfadoxine were designed, which gave rise to an important prototype that was more active than both chloroquine and sulfadoxine. Hybrids between chloroquine-atorvastatin and primaquine-atorvastatin were also synthesized and shown to be more potent than the parent drugs alone. Additionally, among the quinoline derivatives, new mefloquine derivatives were synthesized. Among the non-quinoline derivatives, we obtained excellent results with the triazolopyrimidine nucleus, which gave us prototype I that inspired the synthesis of new heterocycles. The pyrazolopyrimidine derivatives stood out as non-quinoline derivatives that are potent inhibitors of the P. falciparum dihydroorotate dehydrogenase (PfDHODH) enzyme. We also examined the pyrazolopyridine and pyrazolopyrimidine nuclei.


Assuntos
Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Desenvolvimento de Medicamentos , Malária/tratamento farmacológico , Plasmodium/efeitos dos fármacos , Animais , Antimaláricos/química , Técnicas de Química Sintética , Relação Dose-Resposta a Droga , Humanos , Malária/parasitologia , Estrutura Molecular , Pirazóis/química , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Piridinas/química , Piridinas/farmacologia , Piridinas/uso terapêutico , Quinolinas/química , Quinolinas/farmacologia , Quinolinas/uso terapêutico
12.
Future Med Chem ; 10(15): 1853-1874, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30019917

RESUMO

Malaria remains one of the most lethal infectious diseases worldwide, and the most severe form is caused by Plasmodium falciparum. In recent decades, the major challenge to treatment of this disease has been the ability of the protozoan parasite to develop resistance to the drugs that are currently in use. Among P. falciparum enzymes, P. falciparum dihydroorotate dehydrogenase has been identified as an important target in drug discovery. Interference with the activity of this enzyme inhibits de novo pyrimidine biosynthesis and consequently prevents malarial infection. Organic synthesis, x-ray crystallography, high-throughput screening and molecular modeling methods such as molecular docking, quantitative structure-activity relationships, structure-based pharmacophore mapping and molecular dynamics simulations have been applied to the discovery of new inhibitors of P. falciparum dihydroorotate dehydrogenase.


Assuntos
Antimaláricos/farmacologia , Inibidores Enzimáticos/farmacologia , Malária/tratamento farmacológico , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/síntese química , Antimaláricos/química , Cristalografia por Raios X , Di-Hidro-Orotato Desidrogenase , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Malária/metabolismo , Modelos Moleculares , Estrutura Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Testes de Sensibilidade Parasitária , Plasmodium falciparum/enzimologia , Relação Estrutura-Atividade
13.
Molecules ; 23(6)2018 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-29794978

RESUMO

The inhibition of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) potentially represents a new treatment option for malaria, as P. falciparum relies entirely on a de novo pyrimidine biosynthetic pathway for survival. Herein, we report a series of pyrimidone derivatives as novel inhibitors of PfDHODH. The most potent compound, 26, showed high inhibition activity against PfDHODH (IC50 = 23 nM), with >400-fold species selectivity over human dihydroorotate dehydrogenase (hDHODH). The brand-new inhibitor scaffold targeting PfDHODH reported in this work may lead to the discovery of new antimalarial agents.


Assuntos
Inibidores Enzimáticos/síntese química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Plasmodium falciparum/enzimologia , Pirimidinonas/síntese química , Di-Hidro-Orotato Desidrogenase , Desenho de Fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Modelos Moleculares , Estrutura Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/química , Pirimidinonas/química , Pirimidinonas/farmacologia , Especificidade da Espécie , Relação Estrutura-Atividade
14.
SAR QSAR Environ Res ; 27(6): 427-40, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27310104

RESUMO

Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) catalyses the fourth reaction of de novo pyrimidine biosynthesis in parasites, and represents an important target for the treatment of malaria. In this study, we describe pharmacophore-based virtual screening combined with docking study and biological evaluation as a rational strategy for identification of novel hits as antimalarial agents. Pharmacophore models were established from known PfDHODH inhibitors using the GALAHAD module with IC50 values ranging from 0.033 µM to 142 µM. The best pharmacophore model consisted of three hydrogen bond acceptor, one hydrogen bond donor and one hydrophobic features. The pharmacophore models were validated through receiver operating characteristic and Günere-Henry scoring methods. The best pharmacophore model as a 3D search query was searched against the IBS database. Several compounds with different structures (scaffolds) were retrieved as hit molecules. Among these compounds, those with a QFIT value of more than 81 were docked in the PfDHODH enzyme to further explore the binding modes of these compounds. In silico pharmacokinetic and toxicities were predicted for the best docked molecules. Finally, the identified hits were evaluated in vivo for their antimalarial activity in a parasite inhibition assay. The hits reported here showed good potential to become novel antimalarial agents.


Assuntos
Antimaláricos/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Plasmodium falciparum/enzimologia , Animais , Antimaláricos/uso terapêutico , Bases de Dados de Compostos Químicos , Di-Hidro-Orotato Desidrogenase , Desenho de Fármacos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Malária/tratamento farmacológico , Camundongos , Simulação de Acoplamento Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Plasmodium berghei , Relação Quantitativa Estrutura-Atividade
15.
SAR QSAR Environ Res ; 27(2): 101-24, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26911561

RESUMO

Plasmodium falciparum, the most fatal parasite that causes malaria, is responsible for over one million deaths per year. P. falciparum dihydroorotate dehydrogenase (PfDHODH) has been validated as a promising drug development target for antimalarial therapy since it catalyzes the rate-limiting step for DNA and RNA biosynthesis. In this study, we investigated the quantitative structure-activity relationships (QSAR) of the antimalarial activity of PfDHODH inhibitors by generating four computational models using a multilinear regression (MLR) and a support vector machine (SVM) based on a dataset of 255 PfDHODH inhibitors. All the models display good prediction quality with a leave-one-out q(2) >0.66, a correlation coefficient (r) >0.85 on both training sets and test sets, and a mean square error (MSE) <0.32 on training sets and <0.37 on test sets, respectively. The study indicated that the hydrogen bonding ability, atom polarizabilities and ring complexity are predominant factors for inhibitors' antimalarial activity. The models are capable of predicting inhibitors' antimalarial activity and the molecular descriptors for building the models could be helpful in the development of new antimalarial drugs.


Assuntos
Antimaláricos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Plasmodium falciparum/efeitos dos fármacos , Relação Quantitativa Estrutura-Atividade , Antimaláricos/química , Di-Hidro-Orotato Desidrogenase , Ligação de Hidrogênio , Ligantes , Modelos Lineares , Simulação de Acoplamento Molecular , Estrutura Molecular , Pirimidinas/biossíntese , Reprodutibilidade dos Testes , Máquina de Vetores de Suporte
16.
Bioorg Med Chem Lett ; 26(2): 265-271, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26707392

RESUMO

Malaria, caused by infections of the human malaria parasites Plasmodium falciparum, is a global infectious parasitic disease. Each year, about three million people died from malaria and the majority of whom are pregnant women and young children. Recently, a number of research attempt to reduce malaria parasite resistance and the toxicity of anti-malarial drugs. Nowadays, Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) was validated as a potent drug target to inhibit malarial activity by blocking pyrimidine biosynthesis. In this study, we employed 3D-QSAR Pharmacophore Generation and Docking-Based Pharmacophore Development to build the pharmacophore by using the collected 67 effective inhibitors against PfDHODH. 3D-QSAR Pharmacophore model, Hypo1, shows the high correlation coefficient (0.935), the lowest RMS deviation (2.15), the predicting accuracy of successful rates to training set (89.4%) and test set compounds (72.4%), respectively, revealing favorable predictive ability and is a reliable for further study. Additionally, Docking-Based Pharmacophore model, DBP-All255, exhibits comparable predictive capability to that of Hypo1, while DBP-Top1 shows poor statistical significance. This study reveals pharmacophore features of Hypo1, built by 3D-QSAR Pharmacophore Generation, are well-complementary to the functional residues in the active site of PfDHODH and is of great reliable for database screening.


Assuntos
Antimaláricos/química , Derivados de Benzeno/química , Compostos Heterocíclicos/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Plasmodium falciparum/enzimologia , Di-Hidro-Orotato Desidrogenase , Ligação de Hidrogênio , Ligantes , Simulação de Acoplamento Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Relação Quantitativa Estrutura-Atividade
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