RESUMO
A new series of pyrazolo[3,4-g]isoquinoline derivatives, diversely substituted at the 4- or 8-position, were synthesized. The results of the kinase inhibitory potency study demonstrated that the introduction of a bromine atom at the 8-position was detrimental to Haspin inhibition, while the introduction of an alkyl group at the 4-position led to a modification of the kinase inhibition profiles. Altogether, the results obtained demonstrated that new pyrazolo[3,4-g]isoquinolines represent a novel family of kinase inhibitors with various selectivity profiles.
Assuntos
Isoquinolinas , Isoquinolinas/farmacologia , Relação Estrutura-AtividadeRESUMO
A computational model for human transketolase was proposed, showing that thiamine diphosphate activation was based on His110 in place of His481 reported in yeast transketolase. In addition, a complete catalytic reaction pathway was investigated using d-xylulose-5-phosphate and d-ribose-5-phosphate as substrates, showing at every step a perfect superimposition of our model with high-resolution crystallographic structures 3MOS, 4KXV, and 4KXX. This study shows that H2N4' of the active thiamine diphosphate "V form" no longer has a self-activating role but allows self-stabilization of the cofactor and of the Breslow intermediate. These advances in our knowledge of the human transketolase mechanism offer interesting prospects for the design of new drugs, this enzyme being involved in several diseases, and for a better understanding of the reactions catalyzed by transketolases from other sources.
Assuntos
Tiamina Pirofosfato , Transcetolase , Catálise , Cristalografia , Humanos , Cinética , Saccharomyces cerevisiae/metabolismo , Tiamina Pirofosfato/metabolismo , Transcetolase/metabolismoRESUMO
New pyrido[3,4-g]quinazoline derivatives were prepared and evaluated for their inhibitory potency toward 5 protein kinases (CLK1, DYRK1A, GSK3, CDK5, CK1). A related pyrido[4,3-h]quinazoline scaffold with an angular structure was also synthesized and its potency against the same protein kinase panel was compared to the analogous pyrido[3,4-g]quinazoline. Best results were obtained for 10-nitropyrido[3,4-g]quinazoline 4 toward CLK1 with nanomolar activities.
Assuntos
Inibidores de Proteínas Quinases/síntese química , Proteínas Quinases/metabolismo , Piridinas/química , Quinazolinas/química , Quinase 5 Dependente de Ciclina/antagonistas & inibidores , Quinase 5 Dependente de Ciclina/metabolismo , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/metabolismo , Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Estrutura Terciária de Proteína , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Quinazolinas/metabolismo , Relação Estrutura-AtividadeRESUMO
We propose the first computational model for transketolase (TK), a thiamine diphosphate (ThDP)-dependent enzyme, using a quantum mechanical/molecular mechanical method on the basis of crystallographic TK structures from yeast and Escherichia coli, together with experimental kinetic data reported in the literature with wild-type and mutant TK. This model allowed us to define a new route for ThDP activation in the enzyme environment. We evidenced a strong interaction between ThDP and Glu418B of the TK active site, itself stabilized by Glu162A. The crucial point highlighted here is that deprotonation of ThDP C2 is not performed by ThDP N4' as reported in the literature, but by His481B, involving a HOH688A molecule bridge. Thus, ThDP N4' is converted from an amino form to an iminium form, ensuring the stabilization of the C2 carbanion or carbene. Finally, ThDP activation proceeds via an intermolecular process and not by an intramolecular one as reported in the literature. More generally, this proposed ThDP activation mechanism can be applied to some other ThDP-dependent enzymes and used to define the entire TK mechanism with donor and acceptor substrates more accurately.
Assuntos
Modelos Moleculares , Proteínas de Saccharomyces cerevisiae/química , Tiamina Pirofosfato/química , Transcetolase/química , Complexo Vitamínico B/química , Substituição de Aminoácidos , Sítios de Ligação , Biocatálise , Domínio Catalítico , Biologia Computacional , Bases de Dados de Proteínas , Dimerização , Transferência de Energia , Ativação Enzimática , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Conformação Molecular , Simulação de Dinâmica Molecular , Mutação , Teoria Quântica , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Homologia Estrutural de Proteína , Termodinâmica , Tiamina Pirofosfato/metabolismo , Transcetolase/genética , Transcetolase/metabolismo , Complexo Vitamínico B/metabolismoRESUMO
The synthesis of new diversely substituted pyrido[3,4-g]quinazolines is described. The inhibitory potencies of prepared compounds toward a panel of five CMGC protein kinases (CDK5, CLK1, DYRK1A, CK1, GSK3), that are known to play a potential role in Alzheimer's disease, were evaluated. The best overall kinase inhibition profile was found for nitro compound 4 bearing an ethyl group at the 5-position.
Assuntos
Proteínas Tirosina Quinases/antagonistas & inibidores , Quinazolinas/síntese química , Quinazolinas/farmacologia , Sítios de Ligação , Ativação Enzimática/efeitos dos fármacos , Nitrocompostos/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/classificação , Piridinas/síntese química , Piridinas/química , Piridinas/farmacologia , Quinazolinas/químicaRESUMO
A derivative of the staurosporine aglycon (K252c), in which the lactam ring was replaced by a pyrazole moiety, was synthesized. The resulting indolopyrazolocarbazole (3) inhibited Pim isoforms 1-3 whereas it did not impair the activity of two known targets of K252c, protein kinase C isoforms α and γ. Compound 3 exhibited moderate cytotoxic activity toward human leukemia and colon carcinoma cell lines (K562 and HCT116), strongly suggesting that this new scaffold deserves further investigations for treatment of malignancies associated with Pim activity.
Assuntos
Pirazóis/química , Estaurosporina/síntese química , Estaurosporina/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Células K562 , Modelos Moleculares , Proteína Quinase C/efeitos dos fármacos , Proteína Quinase C-alfa/efeitos dos fármacos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Estaurosporina/química , Relação Estrutura-AtividadeRESUMO
A new series of nitro or amino substituted pyrazolo[4,3-a]phenanthridines was synthesized in 6 steps from 5-bromo-6-nitroindazole. The evaluation of their inhibitory potency toward Pim kinases demonstrated that the nitro series could be considered as an interesting starting point for the development of new Pim kinase inhibitors, especially Pim-3. A preferential binding mode was suggested by molecular modeling experiments for nitro series and Pim-1/Pim-3 ATP-binding sites. Moreover, the most active compounds exhibited antiproliferative activities toward PC3 cells in the micromolar range.
Assuntos
Fenantridinas/farmacologia , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Pirazóis/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Fenantridinas/síntese química , Fenantridinas/química , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-AtividadeRESUMO
The synthesis of new pyrrolocarbazoles substituted at N-1/N-10 positions is described. All the compounds tested demonstrated moderate to high Pim-1/Pim-3 kinase inhibitory potency. The most active inhibitors identified in this series (3, 17) have an alkyl chain bridging the N-1 and N-10 positions. These compounds (3, 17) exhibited apoptosis-inducing activity toward acute myeloid leukemia IPC-81 cells, but not toward normal fibroblasts.
Assuntos
Carbazóis/química , Carbazóis/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carbazóis/síntese química , Linhagem Celular Tumoral , Humanos , Leucemia Mieloide Aguda/enzimologia , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/síntese química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Pirróis/síntese química , Pirróis/química , Pirróis/farmacologiaRESUMO
The synthesis and Pim kinase inhibition potency of a new series of pyrrolo[2,3-g]indazole derivatives is described. The results obtained in this preliminary structure-activity relationship study pointed out that sub-micromolar Pim-1 and Pim-3 inhibitory potencies could be obtained in this series, more particularly for compounds 10 and 20, showing that pyrrolo[2,3-g]indazole scaffold could be used for the development of new potent Pim kinase inhibitors. Molecular modeling experiments were also performed to study the binding mode of these compounds in Pim-3 ATP-binding pocket.
Assuntos
Indazóis/química , Indazóis/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Pirróis/química , Pirróis/farmacologia , Cristalografia por Raios X , Modelos Moleculares , Proteínas Proto-Oncogênicas c-pim-1/química , Relação Estrutura-AtividadeRESUMO
New 1,6-dihydropyrazolo[4,3-c]carbazoles and 3,6-dihydropyrazolo[3,4-c]carbazoles were prepared and evaluated for their Pim kinase inhibitory potencies as well as their antiproliferative activities toward two prostatic cancer cell lines. Pyrazolocarbazole 15a was found to be a potent Pim kinase modulator with inhibitory potency toward the three isoforms. Compound 6c strongly inhibited Pim-3 with weaker effect toward Pim-1 and Pim-2, and thus could be used as an interesting molecular tool to study Pim-3 biological functions.
Assuntos
Carbazóis/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Carbazóis/síntese química , Carbazóis/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Masculino , Modelos Moleculares , Neoplasias da Próstata/tratamento farmacológico , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirazóis/síntese química , Pirazóis/química , Pirazóis/farmacologiaRESUMO
BACKGROUND: The subjective visual vertical (SVV, the visual estimation of gravitational direction) is commonly considered as an indicator of the sense of orientation. The present study examined the impact of two methodological factors (the angle size of the stimulus and the participant's gender) on deviations of the SVV caused by head tilt. Forty healthy participants (20 men and 20 women) were asked to make visual vertical adjustments of a light bar with their head held vertically or roll-tilted by 30° to the left or to the right. Line angle sizes of 0.95° and 18.92° were presented. RESULTS: The SVV tended to move in the direction of head tilt in women but away from the direction of head tilt in men. Moreover, the head-tilt effect was also modulated by the stimulus' angle size. The large angle size led to deviations in the direction of head-tilt, whereas the small angle size had the opposite effect. CONCLUSIONS: Our results showed that gender and line angle size have an impact on the evaluation of the SVV. These findings must be taken into account in the growing body of research that uses the SVV paradigm in disease settings. Moreover, this methodological issue may explain (at least in part) the discrepancies found in the literature on the head-tilt effect.
Assuntos
Movimentos da Cabeça/fisiologia , Cabeça/fisiologia , Orientação/fisiologia , Propriocepção/fisiologia , Adulto , Feminino , Humanos , Masculino , Fatores Sexuais , Percepção Espacial/fisiologia , Percepção Visual/fisiologiaRESUMO
Di- and trimeric quinoline derivatives have been recently described as potential modulators of Bcl-2 family protein interactions. However, only a few trimeric compounds have been described so far and an enlargement of the number of analogs of this class is needed to expand the structure-activity relationship study. Therefore, the synthesis of six new trimeric quinoline derivatives is reported. Moreover molecular modeling experiments were performed to study the conformational arrangement of compound 36 in Bak binding site of Bcl-x(L), showing that these compounds could be potential ligands for Bcl-x(L).
Assuntos
Modelos Moleculares , Quinolinas/química , Quinolinas/síntese química , Sítios de Ligação , Polimerização , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Relação Estrutura-Atividade , Proteína Killer-Antagonista Homóloga a bcl-2/química , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/metabolismoRESUMO
The synthesis of new pyrrolo[2,3-a]carbazole derivatives diversely substituted at the C-6 to C-9 positions is described. These compounds were tested for their kinase inhibitory potencies toward three kinases (Pim-1, Pim-2, Pim-3) as well as for their in vitro antiproliferative activities toward a human fibroblast primary culture and three human solid cancer cell lines (PC3, DU145, and PA 1). Moreover, molecular docking studies were performed to explain the enhanced inhibitory activity of the most active compound 3d.
Assuntos
Antineoplásicos/síntese química , Carbazóis/química , Inibidores de Proteínas Quinases/síntese química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Antineoplásicos/química , Antineoplásicos/toxicidade , Sítios de Ligação , Carbazóis/síntese química , Carbazóis/toxicidade , Linhagem Celular , Simulação por Computador , Humanos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/toxicidade , Proteínas Serina-Treonina Quinases/metabolismo , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-pim-1/metabolismoRESUMO
Mechanical Allodynia (MA), a frequent chronic pain symptom caused by innocuous stimuli, constitutes an unmet medical need, as treatments using analgesics available today are not always effective and can be associated with important side-effects. A series of 3,5-disubstituted pyridin-2(1H)-ones was designed, synthesized and evaluated in vivo toward a rat model of inflammatory MA. We found that the series rapidly and strongly prevented the development of MA. 3-(2-Bromophenyl)-5-(phenylamino)pyridin-2(1H)-one 69, the most active compound of the series, was also able to quickly reverse neuropathic MA in rats. Next, when 69 was evaluated toward a panel of 50 protein kinases (PK) in order to identify its potential biological target(s), we found that 69 is a p38α MAPK inhibitor, a PK known to contribute to pain hypersensitivity in animal models. 3,5-Disubstituted pyridin-2(1H)-ones thus could represent a novel class of analgesic for the treatment of MA.
Assuntos
Analgésicos/uso terapêutico , Hiperalgesia/tratamento farmacológico , Piridonas/uso terapêutico , Analgésicos/síntese química , Analgésicos/química , Animais , Relação Dose-Resposta a Droga , Estrutura Molecular , Medição da Dor , Piridonas/síntese química , Piridonas/química , Ratos , Relação Estrutura-AtividadeRESUMO
The synthesis and solution conformation of homo-oligomers of beta-aminoacids, beta-N-mannofuranosyl-3-ulosonic acids, have been studied by NMR, MD simulation, and circular dichroism. These oligomers feature a spirocyclic disubstitution and a N,O-acetal functionality at the beta-carbon of the backbone, an unprecedented situation in the realm of beta-peptides. Our study shows that tetramer 10 and hexamer 11 adopt a characteristic secondary structure. In the hexamer 11, NMR investigations coupled with MD simulations suggest the preference for a double C(8) turn forming conformation.
Assuntos
Furanos/química , Manose/química , Peptídeos/química , Peptídeos/síntese química , Dissacarídeos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Soluções/químicaRESUMO
The first synthesis of functionalized beta-peptoid macrocycles is reported. X-ray crystallographic structure of tetramer 9 reveals a C2-symmetrical derivative with unexpected all-cis-amide bonds and spatial disposition of the appendages toward the two opposite faces of the ring. Quantum calculations suggest that 9 is locked in this layout. These macrocycles constitute novel promising templates for multimeric ligation of biologically active ligands. The concept was exemplified by chemical decoration of tetramer 9 via "click" reactions.
Assuntos
Peptídeos Cíclicos/síntese química , Peptoides/síntese química , Cristalografia por Raios X , Ciclização , Modelos Moleculares , Peptídeos Cíclicos/química , Peptoides/química , Conformação Proteica , EstereoisomerismoRESUMO
A short and efficient synthesis, based on a one-step double elimination, of a key intermediate in the synthesis of various glucocorticosteroids has been developed. This method can be carried out on large scale for further industrial applications. The synthesis allowed us to identify a novel prednisolone derivative 10 and its anti-inflammatory activity was determined in an in vivo model of inflammation. In order to understand the regioselectivity of the double elimination under various conditions, mechanistic studies were undertaken and confirmed the experimental results. We also propose a mechanism for the formation of the new steroid 10 studied by molecular modeling.
Assuntos
Glucocorticoides/química , Glucocorticoides/síntese química , Animais , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Técnicas de Química Sintética , Edema/tratamento farmacológico , Glucocorticoides/farmacologia , Glucocorticoides/uso terapêutico , Masculino , Camundongos , Modelos Moleculares , Conformação Molecular , Prednisolona/síntese química , Prednisolona/química , Prednisolona/farmacologia , Prednisolona/uso terapêuticoRESUMO
The design and synthesis of new pyrido[3,4-g]quinazoline derivatives is described as well as their protein kinase inhibitory potencies toward five CMGC family members (CDK5, CK1, GSK3, CLK1 and DYRK1A). The interest for this original tricyclic heteroaromatic scaffold as modulators of CLK1/DYRK1A activity was validated by nanomolar potencies (compounds 12 and 13). CLK1 co-crystal structures with two inhibitors revealed the binding mode of these compounds within the ATP-binding pocket.
Assuntos
Desenho de Fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/química , Quinazolinas/síntese química , Quinazolinas/farmacologia , Sequência de Aminoácidos , Técnicas de Química Sintética , Cristalografia por Raios X , Humanos , Modelos Moleculares , Conformação Proteica , Inibidores de Proteínas Quinases/química , Quinazolinas/química , Relação Estrutura-AtividadeRESUMO
The characterization of biorelevant media simulating the upper part of the gastrointestinal tract in the fasted and fed states was investigated by classical determination of physicochemical parameters such as pH, osmolality, surface tension and results were compared to in vivo physiological data. Incorporation of fatty material, in order to better simulate the influence of high fat meal was also performed. Stability and characterization of this medium was studied and compared to classical FeSSIF. Micelle characterization and computer dynamic simulation were performed in order to understand the interaction between lecithin and taurocholate and possible interactions between mixed micelle and drugs. The addition of NaTc, lecithin, and/or fatty materials has no influence on pH and osmolality, whereas the presence of fatty material modifies the surface tension. Values of FaSSIF and FeSSIF are in accordance with in vivo parameters and the presence of micelles can simulate the gastrointestinal environment. Modelization of micelles by computer simulation led to a model of mixed micelles in which structures of NaTc interact either by their hydrophilic or hydrophobic phase to give a bilayer stable model in which the lecithin molecule can insert its long carbon chain. The micelle structure is stable and can enhance dissolution of hydrophobic molecules by hydrophobic interaction with the numerous hydrophobic spaces available in the multilayer hydrophilic/hydrophobic layer.
Assuntos
Jejum , Trato Gastrointestinal/fisiologia , Micelas , Simulação por Computador , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Tensão SuperficialRESUMO
The Pim protein kinases (provirus insertion site of Moloney murine leukemia virus) have been identified as important actors involved in tumor cell survival, proliferation, migration and invasion. Therefore, inhibition of Pim activity by low molecular weight compounds is under investigation as a part of anticancer therapeutic strategies. We have synthesized a series of pyrrolo[2,3-a]carbazole derivatives that significantly inhibited Pim protein kinases at submicromolar concentrations. Particularly, benzodiazocine derivative 1 potently inhibited Pim-1 and -3 isoforms in in vitro kinase assays (IC50 8 nM and 13 nM, respectively), whereas Pim-2 activity was less affected (IC50 350 nM). We show here that no inhibitory effect of 1 was detectable at 1 µM against other 22 serine/threonine and tyrosine kinases. In addition, 1, possessing a planar pyrrolocarbazole scaffold, demonstrated no significant binding to DNA, nor was it a potent topoisomerase I inhibitor, suggesting that 1 is likely to be highly selective for Pim-1 and -3. Importantly, whereas 1 exerted a negligible cytotoxicity for human colon carcinoma HCT116 cell line at concentrations >10 µM within 72 h of cell exposure, it synergized at nontoxic concentrations with the antitumor drug doxorubicin (Dox) in killing HCT116 cells: IC50 of Dox alone and Dox+1 were ~200 nM and ~25 nM, respectively. These data strongly suggest that 1 emerges as a prospective antitumor drug candidate due to its selectivity to individual Pim protein kinases and the ability to potentiate the efficacy of conventional chemotherapeutics.