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1.
iScience ; 25(8): 104771, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35982797

RESUMO

Bromocriptine is approved as a diabetes therapy, yet its therapeutic mechanisms remain unclear. Though bromocriptine's actions have been mainly attributed to the stimulation of brain dopamine D2 receptors (D2R), bromocriptine also targets the pancreas. Here, we employ bromocriptine as a tool to elucidate the roles of catecholamine signaling in regulating pancreatic hormone secretion. In ß-cells, bromocriptine acts on D2R and α2A-adrenergic receptor (α2A-AR) to reduce glucose-stimulated insulin secretion (GSIS). Moreover, in α-cells, bromocriptine acts via D2R to reduce glucagon secretion. α2A-AR activation by bromocriptine recruits an ensemble of G proteins with no ß-arrestin2 recruitment. In contrast, D2R recruits G proteins and ß-arrestin2 upon bromocriptine stimulation, demonstrating receptor-specific signaling. Docking studies reveal distinct bromocriptine binding to α2A-AR versus D2R, providing a structural basis for bromocriptine's dual actions on ß-cell α2A-AR and D2R. Together, joint dopaminergic and adrenergic receptor actions on α-cell and ß-cell hormone release provide a new therapeutic mechanism to improve dysglycemia.

2.
J Med Chem ; 62(22): 10391-10401, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31663733

RESUMO

Sterol 14α-demethylases (CYP51) are the cytochrome P450 enzymes required for biosynthesis of sterols in eukaryotes, the major targets for antifungal agents and prospective targets for treatment of protozoan infections. Human CYP51 could be and, for a while, was considered as a potential target for cholesterol-lowering drugs (the role that is now played by statins, which are also in clinical trials for cancer) but revealed high intrinsic resistance to inhibition. While microbial CYP51 enzymes are often inhibited stoichiometrically and functionally irreversibly, no strong inhibitors have been identified for human CYP51. In this study, we used comparative structure/functional analysis of CYP51 orthologs from different biological kingdoms and employed site-directed mutagenesis to elucidate the molecular basis for the resistance of the human enzyme to inhibition and also designed, synthesized, and characterized new compounds. Two of them inhibit human CYP51 functionally irreversibly with their potency approaching the potencies of azole drugs currently used to inhibit microbial CYP51.


Assuntos
Inibidores de 14-alfa Desmetilase/química , Inibidores de 14-alfa Desmetilase/farmacologia , Esterol 14-Desmetilase/química , Esterol 14-Desmetilase/genética , Inibidores de 14-alfa Desmetilase/síntese química , Animais , Domínio Catalítico , Cristalografia por Raios X , Desenho de Fármacos , Humanos , Estrutura Molecular , Mutagênese Sítio-Dirigida , Proteínas de Protozoários/antagonistas & inibidores , Esterol 14-Desmetilase/metabolismo
3.
ACS Med Chem Lett ; 10(4): 463-468, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30996780

RESUMO

Small molecule inhibitors of the HIV-1 nucleocapsid protein (NC) are considered as promising agents in the treatment of HIV/AIDS. In an effort to exploit the privileged 2-amino-4-phenylthiazole moiety in NC inhibition, here we conceived, synthesized, and tested in vitro 18 NC inhibitors (NCIs) bearing a double functionalization. In these NCIs, one part of the molecule is deputed to interact noncovalently with the NC hydrophobic pocket, while the second portion is designed to interact with the N-terminal domain of NC. This binding hypothesis was verified by molecular dynamics simulations, while the linkage between these two pharmacophores was found to enhance antiretroviral activity both on the wild-type virus and on HIV-1 strains with resistance to currently licensed drugs. The two most interesting compounds 6 and 13 showed no cytotoxicity, thus becoming valuable leads for further investigations.

4.
J Med Chem ; 61(23): 10910-10921, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30451500

RESUMO

Sterol 14α-demethylases (CYP51) are cytochrome P450 enzymes essential for sterol biosynthesis in eukaryotes and therapeutic targets for antifungal azoles. Multiple attempts to repurpose antifungals for treatment of human infections with protozoa (Trypanosomatidae) have been undertaken, yet so far none of them have revealed sufficient efficacy. VNI and its derivative VFV are two potent experimental inhibitors of Trypanosomatidae CYP51, effective in vivo against Chagas disease, visceral leishmaniasis, and sleeping sickness and currently under consideration as antiprotozoal drug candidates. However, VNI is less potent against Leishmania and drug-resistant strains of Trypanosoma cruzi and VFV, while displaying a broader spectrum of antiprotozoal activity, and is metabolically less stable. In this work we have designed, synthesized, and characterized a set of close analogues and identified two new compounds (7 and 9) that exceed VNI/VFV in their spectra of antiprotozoal activity, microsomal stability, and pharmacokinetics (tissue distribution in particular) and, like VNI/VFV, reveal no acute toxicity.


Assuntos
Inibidores de 14-alfa Desmetilase/química , Inibidores de 14-alfa Desmetilase/farmacologia , Doença de Chagas/tratamento farmacológico , Desenho de Fármacos , Esterol 14-Desmetilase/metabolismo , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/fisiologia , Inibidores de 14-alfa Desmetilase/metabolismo , Inibidores de 14-alfa Desmetilase/uso terapêutico , Antiprotozoários/química , Antiprotozoários/metabolismo , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Estabilidade de Medicamentos , Humanos , Microssomos/metabolismo , Modelos Moleculares , Conformação Proteica , Esterol 14-Desmetilase/química
5.
J Med Chem ; 61(13): 5679-5691, 2018 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-29894182

RESUMO

Because of the increase in the number of immunocompromised patients, the incidence of invasive fungal infections is growing, but the treatment efficiency remains unacceptably low. The most potent clinical systemic antifungals (azoles) are the derivatives of two scaffolds: ketoconazole and fluconazole. Being the safest antifungal drugs, they still have shortcomings, mainly because of pharmacokinetics and resistance. Here, we report the successful use of the target fungal enzyme, sterol 14α-demethylase (CYP51), for structure-based design of novel antifungal drug candidates by minor modifications of VNI [( R)- N-(1-(2,4-dichlorophenyl)-2-(1 H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzamide)], an inhibitor of protozoan CYP51 that cures Chagas disease. The synthesis of fungi-oriented VNI derivatives, analysis of their potencies to inhibit CYP51s from two major fungal pathogens ( Aspergillus fumigatus and Candida albicans), microsomal stability, effects in fungal cells, and structural characterization of A. fumigatus CYP51 in complexes with the most potent compound are described, offering a new antifungal drug scaffold and outlining directions for its further optimization.


Assuntos
Aspergillus fumigatus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Desenho de Fármacos , Imidazóis/síntese química , Imidazóis/farmacologia , Esterol 14-Desmetilase/metabolismo , Inibidores de 14-alfa Desmetilase/síntese química , Inibidores de 14-alfa Desmetilase/química , Inibidores de 14-alfa Desmetilase/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Aspergillus fumigatus/enzimologia , Candida albicans/enzimologia , Domínio Catalítico , Técnicas de Química Sintética , Cristalografia por Raios X , Imidazóis/química , Ligantes , Modelos Moleculares , Esterol 14-Desmetilase/química
6.
Parasitology ; 145(14): 1820-1836, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29642960

RESUMO

The efficiency of treatment of human infections with the unicellular eukaryotic pathogens such as fungi and protozoa remains deeply unsatisfactory. For example, the mortality rates from nosocomial fungemia in critically ill, immunosuppressed or post-cancer patients often exceed 50%. A set of six systemic clinical azoles [sterol 14α-demethylase (CYP51) inhibitors] represents the first-line antifungal treatment. All these drugs were discovered empirically, by monitoring their effects on fungal cell growth, though it had been proven that they kill fungal cells by blocking the biosynthesis of ergosterol in fungi at the stage of 14α-demethylation of the sterol nucleus. This review briefs the history of antifungal azoles, outlines the situation with the current clinical azole-based drugs, describes the attempts of their repurposing for treatment of human infections with the protozoan parasites that, similar to fungi, also produce endogenous sterols, and discusses the most recently acquired knowledge on the CYP51 structure/function and inhibition. It is our belief that this information should be helpful in shifting from the traditional phenotypic screening to the actual target-driven drug discovery paradigm, which will rationalize and substantially accelerate the development of new, more efficient and pathogen-oriented CYP51 inhibitors.


Assuntos
Inibidores de 14-alfa Desmetilase/uso terapêutico , Família 51 do Citocromo P450/antagonistas & inibidores , Fungos/efeitos dos fármacos , Parasitos/efeitos dos fármacos , Animais , Antifúngicos/farmacologia , Fungemia/tratamento farmacológico , Fungemia/mortalidade , Humanos , Modelos Moleculares , Ligação Proteica , Especificidade por Substrato , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma cruzi/efeitos dos fármacos
7.
J Biol Chem ; 292(16): 6728-6743, 2017 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-28258218

RESUMO

With some advances in modern medicine (such as cancer chemotherapy, broad exposure to antibiotics, and immunosuppression), the incidence of opportunistic fungal pathogens such as Candida albicans has increased. Cases of drug resistance among these pathogens have become more frequent, requiring the development of new drugs and a better understanding of the targeted enzymes. Sterol 14α-demethylase (CYP51) is a cytochrome P450 enzyme required for biosynthesis of sterols in eukaryotic cells and is the major target of clinical drugs for managing fungal pathogens, but some of the CYP51 key features important for rational drug design have remained obscure. We report the catalytic properties, ligand-binding profiles, and inhibition of enzymatic activity of C. albicans CYP51 by clinical antifungal drugs that are used systemically (fluconazole, voriconazole, ketoconazole, itraconazole, and posaconazole) and topically (miconazole and clotrimazole) and by a tetrazole-based drug candidate, VT-1161 (oteseconazole: (R)-2-(2,4-difluorophenyl)-1,1-difluoro-3-(1H-tetrazol-1-yl)-1-(5-(4-(2,2,2-trifluoroethoxy)phenyl)pyridin-2-yl)propan-2-ol). Among the compounds tested, the first-line drug fluconazole was the weakest inhibitor, whereas posaconazole and VT-1161 were the strongest CYP51 inhibitors. We determined the X-ray structures of C. albicans CYP51 complexes with posaconazole and VT-1161, providing a molecular mechanism for the potencies of these drugs, including the activity of VT-1161 against Candida krusei and Candida glabrata, pathogens that are intrinsically resistant to fluconazole. Our comparative structural analysis outlines phylum-specific CYP51 features that could direct future rational development of more efficient broad-spectrum antifungals.


Assuntos
Antifúngicos/química , Azóis/química , Candida albicans/enzimologia , Proteínas Fúngicas/química , Esterol 14-Desmetilase/química , Esteróis/biossíntese , Animais , Cristalização , Heme/química , Humanos , Cinética , Ligantes , Testes de Sensibilidade Microbiana , Ligação Proteica , Conformação Proteica , Prótons , Ratos
8.
J Lipid Res ; 57(8): 1552-63, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27313059

RESUMO

Rapidly multiplying cancer cells synthesize greater amounts of cholesterol to build their membranes. Cholesterol-lowering drugs (statins) are currently in clinical trials for anticancer chemotherapy. However, given at higher doses, statins cause serious side effects by inhibiting the formation of other biologically important molecules derived from mevalonate. Sterol 14α-demethylase (CYP51), which acts 10 steps downstream, is potentially a more specific drug target because this portion of the pathway is fully committed to cholesterol production. However, screening a variety of commercial and experimental inhibitors of microbial CYP51 orthologs revealed that most of them (including all clinical antifungals) weakly inhibit human CYP51 activity, even if they display high apparent spectral binding affinity. Only one relatively potent compound, (R)-N-(1-(3,4'-difluorobiphenyl-4-yl)-2-(1H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzamide (VFV), was identified. VFV has been further tested in cellular experiments and found to decrease proliferation of different cancer cell types. The crystal structures of human CYP51-VFV complexes (2.0 and 2.5 Å) both display a 2:1 inhibitor/enzyme stoichiometry, provide molecular insights regarding a broader substrate profile, faster catalysis, and weaker susceptibility of human CYP51 to inhibition, and outline directions for the development of more potent inhibitors.


Assuntos
Inibidores de 14-alfa Desmetilase/química , Antineoplásicos/química , Esterol 14-Desmetilase/química , Antifúngicos , Antiprotozoários/química , Domínio Catalítico , Linhagem Celular Tumoral , Colestadienóis/química , Cristalografia por Raios X , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligação de Hidrogênio , Lanosterol/química , Modelos Moleculares , Ligação Proteica , Conformação Proteica em alfa-Hélice
9.
Eur J Med Chem ; 121: 169-180, 2016 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-27240272

RESUMO

The development of new anti-tubercular agents represents a constant challenge mostly due to the insurgency of resistance to the currently available drugs. In this study, a set of 60 molecules were selected by screening the Asinex and the ZINC collections and an in house library by means of in silico ligand-based approaches. Biological assays in Mycobacterium tuberculosis H37Ra ATCC 25177 strain highlighted (±)-1-(4-chlorophenyl)-2-(1H-imidazol-1-yl)ethyl-4-(3,4-dichlorophenyl)piperazine-1-carboxylate (5i) and 3-(4-chlorophenyl)-5-(2,4-dimethylpyrimidin-5-yl)-2-methylpyrazolo[1.5-a]pyrimidin-7(4H)-one (42) as the most potent compounds, having a Minimum Inhibitory Concentration (MIC) of 4 and 2 µg/mL respectively. These molecules represent a good starting point for further optimization of effective anti-TB agents.


Assuntos
Antituberculosos/química , Antituberculosos/farmacologia , Simulação por Computador , Descoberta de Drogas , Ligantes , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas
10.
J Enzyme Inhib Med Chem ; 30(1): 166-72, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24517367

RESUMO

Metal ions, especially copper, zinc and iron, play an important role in the neurodegeneration process because they can affect protein misfolding, leading to the formation of the amyloid deposits and oxidative stress leading to reactive oxygen species (ROS). Here we report the synthesis and evaluation as antioxidant and metal chelating agents of 3,4-dihydroxybenzoic acid derivatives. Synthesized compounds were tested by the 2,2-diphenyl-2-picrylhydrazyl (DPPH) method showing a radical scavenging ability (EC50=0.093-0.118 µM) higher than Trolox used as reference. Furthermore, these compounds were able to bind both iron and copper, especially the iron (III), by the formation of hexa-coordinated complexes. Synthesized compounds were tested to evaluate their ability to inhibit acetyl- and butyryl-cholinesterase; the obtained results have demonstrated that they are selective inhibitors of AChE (Ki=1.5-18.9 µM) and result weakly active versus butyrylcholinesterase (BChE).


Assuntos
Acetilcolinesterase/química , Antioxidantes/síntese química , Quelantes/síntese química , Inibidores da Colinesterase/síntese química , Hidroxibenzoatos/síntese química , Animais , Antioxidantes/química , Compostos de Bifenilo/antagonistas & inibidores , Butirilcolinesterase/química , Quelantes/química , Inibidores da Colinesterase/química , Cromanos/química , Complexos de Coordenação/química , Cobre/química , Desenho de Fármacos , Hidroxibenzoatos/química , Ferro/química , Cinética , Simulação de Acoplamento Molecular , Picratos/antagonistas & inibidores , Relação Estrutura-Atividade , Torpedo
11.
J Med Chem ; 57(15): 6704-17, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-25033013

RESUMO

Chagas disease, which was once thought to be confined to endemic regions of Latin America, has now gone global, becoming a new worldwide challenge with no cure available. The disease is caused by the protozoan parasite Trypanosoma cruzi, which depends on the production of endogenous sterols, and therefore can be blocked by sterol 14α-demethylase (CYP51) inhibitors. Here we explore the spectral binding parameters, inhibitory effects on T. cruzi CYP51 activity, and antiparasitic potencies of a new set of ß-phenyl imidazoles. Comparative structural characterization of the T. cruzi CYP51 complexes with the three most potent inhibitors reveals two opposite binding modes of the compounds ((R)-6, EC50=1.2 nM, vs (S)-2/(S)-3, EC50=1.0/5.5 nM) and suggests the entrance into the CYP51 substrate access channel and the heme propionate-supporting ceiling of the binding cavity as two distinct areas of the protein that enhance molecular recognition and therefore could be used for the development of more effective antiparasitic drugs.


Assuntos
Inibidores de 14-alfa Desmetilase/química , Carbamatos/química , Imidazóis/química , Esterol 14-Desmetilase/metabolismo , Tripanossomicidas/química , Trypanosoma cruzi/enzimologia , Inibidores de 14-alfa Desmetilase/síntese química , Inibidores de 14-alfa Desmetilase/farmacologia , Carbamatos/síntese química , Carbamatos/farmacologia , Cristalografia por Raios X , Desenho de Fármacos , Imidazóis/síntese química , Imidazóis/farmacologia , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Estereoisomerismo , Esterol 14-Desmetilase/química , Tripanossomicidas/síntese química , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos
12.
ISRN Org Chem ; 2014: 621592, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24955255

RESUMO

The use of electrogenerated acetonitrile anion allows the alkylation of N-Boc-4-aminopyridine in very high yields, under mild conditions and without by-products. The high reactivity of this base is due to its large tetraethylammonium counterion, which leaves the acetonitrile anion "naked." The deprotection of the obtained compounds led to high yields in N-alkylated 4-aminopyridines. Nonsymmetrically dialkylated 4-aminopyridines were obtained by subsequent reaction of monoalkylated ones with t-BuOK and alkyl halides, while symmetrically dialkylated 4-aminopyridines were obtained by direct reaction of 4-aminopyridine with an excess of t-BuOK and alkyl halides. Some mono- and dialkyl-4-aminopyridines were selected to evaluate antifungal and antiprotozoal activity; the dialkylated 4-aminopyridines 3ac, 3ae and 3ff showed antifungal towards Cryptococcus neoformans; whereas 3cc, 3ee and 3ff showed antiprotozoal activity towards Leishmania infantum and Plasmodium falciparum.

13.
Bioorg Med Chem Lett ; 24(6): 1502-5, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24582984

RESUMO

The aim of this study was to evaluate the caffeic acid (1) and ester derivatives (2-10) against Candida albicans biofilm and to investigate whether these compounds are able to inhibit the biofilm formation or destroy pre-formed biofilm. Caffeic acid ester 7, cinnamic acid ester 8 and 3,4-dihydroxybenzoic acid ester 10 are more active than fluconazole, used as reference drug, both on biofilm in formation with MIC50 values of 32, 32 and 16µg/mL, respectively, and in the early stage of biofilm formation (4h) with MIC50 values of 64, 32 and 64µg/mL, respectively. These esters result also more active than fluconazole on mature biofilm (24h), especially 8 and 10 with MIC50 values of 64µg/mL.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Ácidos Cafeicos/química , Ácidos Cafeicos/farmacologia , Candida albicans/fisiologia , Antifúngicos/síntese química , Ácidos Cafeicos/síntese química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana
14.
J Chem Inf Model ; 53(6): 1463-74, 2013 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-23617317

RESUMO

Pharmacophoric mapping is a useful procedure to frame, especially when crystallographic receptor structures are unavailable as in ligand-based studies, the hypothetical site of interaction. In this study, 71 pyrrole derivatives active against M. tuberculosis were used to derive through a recent new 3-D QSAR protocol, 3-D QSAutogrid/R, several predictive 3-D QSAR models on compounds aligned by a previously reported pharmacophoric application. A final multiprobe (MP) 3-D QSAR model was then obtained configuring itself as a tool to derive pharmacophoric quantitative models. To stress the applicability of the described models, an external test set of unrelated and newly synthesized series of R-4-amino-3-isoxazolidinone derivatives found to be active at micromolar level against M. tuberculosis was used, and the predicted bioactivities were in good agreement with the experimental values. The 3-D QSAutogrid/R procedure proved to be able to correlate by a single multi-informative scenario the different activity molecular profiles thus confirming its usefulness in the rational drug design approach.


Assuntos
Antituberculosos/química , Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Pirróis/química , Pirróis/farmacologia , Relação Quantitativa Estrutura-Atividade , Desenho de Fármacos , Humanos , Modelos Moleculares , Oxazolidinonas/química , Oxazolidinonas/farmacologia , Tuberculose/tratamento farmacológico
15.
ACS Med Chem Lett ; 4(6): 538-41, 2013 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-24900706

RESUMO

The antiparasitic activity of azole and new 4-aminopyridine derivatives has been investigated. The imidazoles 1 and 3-5 showed a potent in vitro antichagasic activity with IC50 values in the low nanomolar concentration range. The (S)-1, (S)-3, and (S)-5 enantiomers showed (up to) a thousand-fold higher activity than the reference drug benznidazole and furthermore low cytotoxicity on rat myogenic L6 cells.

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