RESUMO
The anodic oxidation of a natural antioxidative catechol, hydroxytyrosol, was developed in an acetonitrile/dimethylsulfoxide (or acetonitrile/water) solvent mixture to produce in a stable way the resulting non-activated o-quinone and generate structural analogues. 2-Amino-2,3-dihydro-1,4-benzodioxane derivatives were obtained as two regioisomers in good to high overall yields (65-90%) and 1 : 3 ratios, through an inverse electron demand Diels-Alder (IEDDA) reaction between the electrogenerated o-quinone and tertiary enamines. The insertion of an electron withdrawing (or electron donating) group on the catechol modified their relative proportions, so that the reaction became regiospecific. With some aliphatic enamines, a competitive 1,6-Michael addition took place, affording 2-hydroxy-1,2,4,5-tetrahydrobenzo[d]oxepine compounds.
RESUMO
A series of achiral indole analogues of the selective sirtuin inhibitor EX-527 (a racemic, substituted 1,2,3,4 tetrahydrocarbazole) was designed to stabilize the bioactive conformation, and synthesized. These new indoles were evaluated against the isolated sirtuin enzymes SIRT1 and SIRT2, and against a panel of nine human cell lines. Structure-activity relationship studies demonstrated the influence of the substituent at position 3 of the indole. The most potent SIRT1 inhibitor 3h, bearing an isopropyl substituent, was as potent as EX-527, and more selective for SIRT1 over SIRT2. Compound 3g, bearing a benzyl substituent, inhibited both sirtuins at micromolar concentration and was more cytotoxic than EX-527 on several cancer cell lines.
Assuntos
Indóis/farmacologia , Sirtuína 1/antagonistas & inibidores , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Indóis/síntese química , Indóis/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Sirtuína 1/metabolismo , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Oligo-analgesia is common in the emergency department (ED). This study aimed at reporting, when initiated by triage nurse, the superior efficacy of inhaled methoxyflurane plus standard of care (m-SoC) analgesia versus placebo plus SoC (p-SoC) for moderate-to-severe trauma-related pain in the hospital ED. METHODS: A randomised, double-blind, placebo-controlled trial was conducted at eight EDs. Adults with pain score ≥4 (11-point numerical rate scale, NRS) at admission were randomised to receive one or two inhalers containing m-SoC or p-SoC. Primary outcome measure was time until pain relief ≤30 mm, assessed on the 100-mm Visual Analogic Scale (VAS). RESULTS: A total of 351 patients were analysed (178 m-SoC; 173 p-SoC). Median pain prior to first inhalation was 66 mm, 75% had severe pain (NRS 6-10). Median time to pain relief was 35 min [95% confidence interval (CI), 28-62] for m-SoC versus not reached in p-SoC (92 - not reached) [hazard ratio), 1.93 (1.43-2.60), P < 0.001]. Pain relief was most pronounced in the severe pain subgroup: hazard ratio, 2.5 (1.7-3.7). As SoC, 24 (7%) patients received weak opioids (6 versus 8%), 4 (1%) strong opioid and 44 (13%) escalated to weak or strong opioids (8 versus 17%, respectively, P = 0.02). Most adverse events were of mild (111/147) intensity. CONCLUSIONS: In this study, we report that methoxyflurane, initiated at triage nurse as part of a multimodal analgesic approach, is effective in achieving pain relief for trauma patients. This effect was particularly pronounced in the severe pain subgroup.
Assuntos
Dor Aguda , Analgesia , Anestésicos Inalatórios , Metoxiflurano , Dor Aguda/tratamento farmacológico , Adulto , Analgésicos Opioides , Anestésicos Inalatórios/uso terapêutico , Método Duplo-Cego , Serviço Hospitalar de Emergência , Hospitais , Humanos , Metoxiflurano/uso terapêuticoRESUMO
Aggregation of amyloid ß peptide (Aß) is an important event in the progression of Alzheimer's disease. Therefore, among the available therapeutic approaches to fight with disease, inhibition of Aß aggregation is widely studied and one of the promising approach for the development of treatments for Alzheimer's disease. Thiosemicarbazone compounds are known for their variety of biological activities. However, the potential of thiosemicarbazone compounds towards inhibition of Aß peptide aggregation and the subsequent toxicity is little explored. Herein, we report synthesis and x-ray crystal structure of novel compound 3-acetyl coumarin thiosemicarbazone and its efficacy toward inhibition of Aß(1-42) peptide aggregation. Our results indicate that 3-acetyl coumarin thiosemicarbazone inhibits Aß(1-42) peptide aggregation up to 80% compared to the parent 3-acetyl coumarin which inhibits 52%. Further, 3-acetyl coumarin thiosemicarbazone provides neuroprotection against Aß-induced cytotoxicity in SH-SY5Y cell line. These findings indicate that thiosemicarbazone modification renders 3-acetyl coumarin neuroprotective properties.
Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/toxicidade , Cumarínicos/química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/toxicidade , Agregados Proteicos/efeitos dos fármacos , Tiossemicarbazonas/química , Tiossemicarbazonas/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Humanos , Modelos Moleculares , Conformação Molecular , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologiaRESUMO
Tryptophanase is a bacterial enzyme involved in the degradation of tryptophan to indole, pyruvate and ammonia, which are compounds that are essential for bacterial survival. Tryptophanase is often overexpressed in stressed cultures. Large amounts of endogenous tryptophanase were purified from Escherichia coli BL21 strain overexpressing another recombinant protein. Tryptophanase was crystallized in space group P6522 in the apo form without pyridoxal 5'-phosphate bound in the active site.
Assuntos
Antiácidos/farmacologia , Proteínas de Escherichia coli/química , Escherichia coli/enzimologia , Triptofanase/química , Técnicas de Cultura de Células , Cristalização , Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/isolamento & purificação , Humanos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Triptofanase/isolamento & purificação , Difração de Raios XRESUMO
A series of phosphinic glutamate derivatives (e.g.LSP1-2111) have been proven to be potent agonists of metabotropic glutamate (mGlu) receptors and shown promising in vivo activity. However, so far all were synthesized and tested as a mixture of two diastereomers whose absolute and relative configurations are not known. In this study, the stereomers were separated on a Crownpack CR(+) column and their absolute configuration was assessed by means of a diastereoselective synthesis. Both separated L-stereomers activated the mGlu4 receptor with EC50's of 0.72 and 4.4 µM for (1S,1'S)-and (1S,1'R)-LSP1-2111, respectively.
Assuntos
Ácido Glutâmico/química , Compostos Organofosforados/química , Ácido Glutâmico/farmacologia , Células HEK293 , Humanos , Modelos Moleculares , Conformação Molecular , Receptores de Glutamato Metabotrópico/agonistasRESUMO
During biogenesis of the 40S and 60S ribosomal subunits, the pre-40S particles are exported to the cytoplasm prior to final cleavage of the 20S pre-rRNA to mature 18S rRNA. Amongst the factors involved in this maturation step, Fap7 is unusual, as it both interacts with ribosomal protein Rps14 and harbors adenylate kinase activity, a function not usually associated with ribonucleoprotein assembly. Human hFap7 also regulates Cajal body assembly and cell cycle progression via the p53-MDM2 pathway. This work presents the functional and structural characterization of the Fap7-Rps14 complex. We report that Fap7 association blocks the RNA binding surface of Rps14 and, conversely, Rps14 binding inhibits adenylate kinase activity of Fap7. In addition, the affinity of Fap7 for Rps14 is higher with bound ADP, whereas ATP hydrolysis dissociates the complex. These results suggest that Fap7 chaperones Rps14 assembly into pre-40S particles via RNA mimicry in an ATP-dependent manner. Incorporation of Rps14 by Fap7 leads to a structural rearrangement of the platform domain necessary for the pre-rRNA to acquire a cleavage competent conformation.
Assuntos
Adenilato Quinase/genética , Regulação Fúngica da Expressão Gênica , Proteínas Nucleares/genética , Nucleosídeo-Trifosfatase/genética , Proteínas Ribossômicas/genética , Subunidades Ribossômicas Menores de Eucariotos/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Difosfato de Adenosina/química , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Adenilato Quinase/química , Adenilato Quinase/metabolismo , Sequência de Aminoácidos , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Modelos Moleculares , Mimetismo Molecular , Dados de Sequência Molecular , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Nucleosídeo-Trifosfatase/química , Nucleosídeo-Trifosfatase/metabolismo , Pyrococcus abyssi/genética , Pyrococcus abyssi/metabolismo , RNA Ribossômico 18S/química , RNA Ribossômico 18S/genética , RNA Ribossômico 18S/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Ribossômicas/química , Proteínas Ribossômicas/metabolismo , Subunidades Ribossômicas Maiores de Eucariotos/genética , Subunidades Ribossômicas Maiores de Eucariotos/metabolismo , Subunidades Ribossômicas Menores de Eucariotos/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Alinhamento de SequênciaRESUMO
BACKGROUND: S100B protein measurement in blood is proposed to exclude the presence of computed tomography (CT) lesions after minor head injury (MHI). We aimed to validate S100B as an accurate and valuable screening tool for MHI diagnosis in a large multicenter study, as well as: 1) to evaluate whether a second S100B blood level determination 3 h after the first one would be informative; 2) to compare the bioclinical performances of the two commercially available automated methods of measurement of S100B for the screening of patients. METHODS: Four thousand and thirty MHI subjects were enrolled in a prospective observational multicenter study; results for serum S100B measurement determined within 3 h after the clinical event (H0) then at H3 were compared to that of cranial CT scans performed with 6 h following the presentation to emergency department. Both the Diasorin and the Roche Diagnostics assays were systematically performed. RESULTS: Cerebral lesions on CT scan were identified with sensitivity and negative-predictive value (NPV) of 96.3% and 99.4% (Diasorin, 1 dissonant case), and of 100% and 100% (Roche Diagnostics, no dissonant case). Sensitivity and NPV at H3 appeared lower than those at H0, due to the rapid decrease in S100B levels. CONCLUSIONS: Serum S100B level on admission of patients with MHI is an accurate and useful screening tool to exclude intracranial lesions. Performing a second late S100B level determination is not informative. The two automated immunoassays appear usable in a similar manner, although the two methods are not interchangeable.
Assuntos
Lesões Encefálicas/sangue , Lesões Encefálicas/diagnóstico , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Adulto , Consumo de Bebidas Alcoólicas/sangue , Automação , Isquemia Encefálica/sangue , Isquemia Encefálica/diagnóstico , França , Humanos , Imunoensaio , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
We have recently reported that cationic thiosulfonato ruthenium complexes [(p-cymene)Ru(bipy)(SSO(2)Ar)](+) (bipy: 2-2'-bipyridine, Ar: phenyl or p-tolyl) react with thiolates (RS(-), R = alkyl or aryl) by cleavage of the S-SO(2) bond and formation of a new S-S bond. In this work, we report that the outcome of the reaction is different if the hydrosulfide anion (R = H) is used, the product obtained being the hydrogen(sulfido) derivative [(p-cymene)Ru(bipy)(SH)](+). The bipy ligand is crucial in this result, and its replacement by ethylenediamine leads to a different product, the trisulfido-bridged dinuclear complex [[(p-cymene)Ru(en)(S)](2)S](2+). These two new species have been fully characterized, including by X-ray diffraction studies, and the two different mechanisms leading to their formation are discussed.
Assuntos
Diaminas/química , Compostos Organometálicos/química , Rutênio/química , Compostos de Sulfidrila/química , Sulfetos/química , Ácidos Sulfônicos/química , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese químicaRESUMO
Through use of the reversible protonation of an iron(II) complex containing a deprotonated carboxamido moiety, we prepared and fully characterized the first hydrogen(sulfido)iron(II) complex stabilized by an intramolecular hydrogen bond, which acts as a H(2)S donor in solution.
Assuntos
Complexos de Coordenação/síntese química , Compostos Ferrosos/síntese química , Compostos de Sulfidrila/síntese química , Complexos de Coordenação/química , Compostos Ferrosos/química , Ligação de Hidrogênio , Modelos Moleculares , Compostos de Sulfidrila/químicaRESUMO
New series of acids and hydroxamic acids linked to five-membered heterocycles including furan, oxazole, 1,2,4- or 1,3,4-oxadiazole, and imidazole were synthesized and tested as inhibitors against the Fe(II) , Co(II) , and Mn(II) forms of E. coli methionine aminopeptidase (MetAP) and as antibacterial agents against wild-type and acrAB E. coli strains. 2-Aryloxazol-4-ylcarboxylic acids appeared as potent and selective inhibitors of the Co(II) MetAP form, with IC(50) values in the micromolar range, whereas 5-aryloxazol-2-ylcarboxylic acid regioisomers and 5-aryl-1,2,4-oxadiazol-3-ylcarboxylic acids were shown to be inefficient against all forms of EcMetAP. Regardless of the heterocycle, all the hydroxamic acids are highly potent inhibitors and are selective for the Mn(II) and Fe(II) forms, with IC(50) values between 1 and 2 µM. One indole hydroxamic acid that we previously reported as a potent inhibitor of E. coli peptide deformylase also demonstrated efficiency against EcMetAP. To gain insight into the positioning of the oxazole heterocycle with reversed substitutions at positions 2 and 5, X-ray crystal structures of EcMetAP-Mn complexed with two such oxazole hydroxamic acids were solved. Irrespective of the [metal]/[apo-MetAP] ratio, the active site consistently contains a dinuclear manganese center, with the hydroxamate as bridging ligand. Asp 97, which adopts a bidentate binding mode to the Mn2 site in the holoenzyme, is twisted in both structures toward the hydroxamate bridging ligand to favor the formation of a strong hydrogen bond. Most of the compounds show weak antibacterial activity against a wild-type E. coli strain. However, increased antibacterial activity was observed mainly for compounds with a 2-substituted phenyl group in the presence of the nonapeptide polymyxin B and phenylalanine-arginine-ß-naphthylamide as permeabilizer and efflux pump blocker, respectively, which boost the intracellular uptake of the inhibitors.
Assuntos
Aminopeptidases/antagonistas & inibidores , Antibacterianos/química , Inibidores Enzimáticos/química , Proteínas de Escherichia coli/antagonistas & inibidores , Escherichia coli/enzimologia , Ácidos Hidroxâmicos/química , Aminopeptidases/metabolismo , Antibacterianos/síntese química , Antibacterianos/farmacologia , Sítios de Ligação , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/metabolismo , Compostos Ferrosos/química , Compostos Heterocíclicos/química , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/farmacologia , Manganês/química , Metionil Aminopeptidases , Estrutura Terciária de Proteína , Relação Estrutura-AtividadeRESUMO
The reaction of the thiosulfonato complexes [(p-cym)Ru(bipy)(S-SO(2)R)](+) (R = Ph, p-Tol) with the thiolates R'S(-) (R' = alkyl or aryl) leads to S-S bond cleavage and to the quantitative formation of the corresponding disulfanido derivatives [(p-cym)Ru(bipy)(S-SR')](+). The aryldisulfanido complexes also react with benzyl thiolate by S-S bond cleavage to give [(p-cym)Ru(bipy)(SSCH(2)Ph)](+).
Assuntos
Compostos Organometálicos/química , Rutênio/química , Ácidos Sulfônicos/química , Enxofre/química , Ligantes , Modelos Moleculares , Conformação Molecular , Compostos Organometálicos/síntese químicaRESUMO
A review of mathematical modeling in metal metabolism is presented. Both endogenous and exogenous metals are considered. Four classes of methods are considered: Petri nets, multi-agent systems, determinist models based on differential equations and stochastic models. For each, a basic theoretical background is given, then examples of applications are given, detailed and commented. Advantages and disadvantages of each class of model are presented. A special attention is given to determinist differential equation models, since almost all models belong to this class.
Assuntos
Metais/metabolismo , Modelos Teóricos , Animais , HumanosRESUMO
COMMD1 (copper metabolism gene MURR1 (mouse U2af1-rs1 region1) domain) belongs to a family of multifunctional proteins that inhibit nuclear factor NF-kappaB. COMMD1 was implicated as a regulator of copper metabolism by the discovery that a deletion of exon 2 of COMMD1 causes copper toxicosis in Bedlington terriers. Here, we report the detailed characterization and specific copper binding properties of purified recombinant human COMMD1 as well as that of the exon 2 product, COMMD(61-154). By using various techniques including native-PAGE, EPR, UV-visible electronic absorption, intrinsic fluorescence spectroscopies as well as DEPC modification of histidines, we demonstrate that COMMD1 specifically binds copper as Cu(II) in 1:1 stoichiometry and does not bind other divalent metals. Moreover, the exon 2 product, COMMD(61-154), alone was able to bind Cu(II) as well as the wild type protein, with a stoichiometry of 1 mol of Cu(II) per protein monomer. The protection of DEPC modification of COMMD1 by Cu(II) implied that Cu(II) binding involves His residues. Further investigation by DEPC modification of COMMD(61-154) and subsequent MALDI MS mapping and MS/MS sequencing identified the protection of His101 and His134 residues in the presence of Cu(II). Fluorescence studies of single point mutants of the full-length protein revealed the involvement of M110 in addition to H134 in direct Cu(II) binding. Taken together, the data provide insight into the function of COMMD1 and especially COMMD(61-154), a product of exon 2 that is deleted in terriers affected by copper toxicosis, as a regulator of copper homeostasis.
Assuntos
Proteínas de Transporte/metabolismo , Cobre/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Proteínas de Transporte/genética , Proteínas de Transporte/isolamento & purificação , Clonagem Molecular , Dietil Pirocarbonato/química , Dimerização , Espectroscopia de Ressonância de Spin Eletrônica , Eletroforese em Gel de Poliacrilamida , Histidina/química , Humanos , Metionina/química , Dados de Sequência Molecular , Estrutura Quaternária de Proteína , Alinhamento de Sequência , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em TandemRESUMO
The isolation and the X-ray crystal structure of physiological copper(II)-L-histidine complex are reported. The neutral five-coordinate complex shows distorted square pyramidal geometry with bidentate and tridentate L-histidine ligands. The basic character of the pendent imidazole group and H-bonding interactions of bidentate L-histidine ligand are important for copper transport. The unique structural features help explain the origin of its thermodynamic stability and kinetic reactivity in human blood along with the ternary copper(II)-amino acid complexes. The role of L-histidine in interaction with copper(II)-albumin, in cellular uptake of copper, and in treatment of Menkes disease can be studied using these results.
Assuntos
Cobre/química , Histidina/química , Compostos Organometálicos/química , Cobre/metabolismo , Cristalografia por Raios X , Histidina/metabolismo , Humanos , Ligação de Hidrogênio , Ligantes , Síndrome dos Cabelos Torcidos/metabolismo , Síndrome dos Cabelos Torcidos/terapia , Estrutura Molecular , Compostos Organometálicos/metabolismoRESUMO
The crystal structure of a novel copper(II) complex with a potentially hexadentate Schiff base ligand derived from l-histidine has been solved by a single-crystal X-ray diffraction method at pH 7.4. The copper(II) ion is coordinated asymmetrically by a tetradentate ligand with the amino and imidazole imido nitrogen atoms on one side versus imino nitrogen and carboxylate oxygen atoms on the other side in a distorted square-planar geometry. The formation of an infinite chain through carboxylate coordination is observed. The novel ligand is obtained by the reaction between the l-histidine molecules coordinated to copper(II) and 4-hydroxy-4-methylpentan-2-one formed by aldol condensation of acetone. This complex provides insights into a possible structural arrangement between copper(II) and l-histidine which is physiologically important and abundantly present in biological systems.
Assuntos
Cobre/química , Histidina/análogos & derivados , Compostos Organometálicos/química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Estrutura Molecular , Bases de Schiff/químicaRESUMO
X-ray absorption spectroscopy provides valuable information on metallic speciation and so has a wide range of applications in bioinorganic systems. In this paper, low-molar-mass metallic complexes as used in pharmaceutical science are focused on. The results of structural studies on metal-based drugs applied as disease treatments, nutritional supplements or tools for diagnostic methods are presented. Then metal speciation (spatial and chemical distribution) in biological samples through micro-XANES imaging experiments are dealt with. Problems arising from the analysis of noisy data collected from these diluted samples are discussed.