RESUMO
Apigenin is a natural flavonoid which is claimed to have many pharmacological activities ranging from simple anti-inflammatory to anticancer action. However, poor dissolution slowed the advancement of this drug through the development pipelines. The objective of this work was to probe ethanol-aided kneading of apigenin with arginine as a new strategy for enhanced dissolution rate. The work was extended to develop rapidly disintegrating tablets of apigenin. Apigenin was mixed with increasing molar ratios of arginine before ethanol-aided kneading. The resulting products were examined using Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction in addition to probing the dissolution characteristics of apigenin. The analytical techniques highlighted the existence of new crystalline species with a possibility of salt formation. The recorded alterations in the crystalline properties were associated with a significant enhancement in the dissolution rate of apigenin. The presence of arginine did not have any negative effect of the cytotoxic power of apigenin. Optimum formulation was successfully prepared as rapidly disintegrating tablets which showed fast liberation of apigenin. The study introduced arginine as a potential excipient for enhanced dissolution of apigenin after ethanol-assisted kneading.
Assuntos
Apigenina/síntese química , Arginina/síntese química , Química Farmacêutica/métodos , Desenvolvimento de Medicamentos/métodos , Etanol/síntese química , Apigenina/metabolismo , Apigenina/farmacologia , Arginina/metabolismo , Arginina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Etanol/metabolismo , Etanol/farmacologia , Células HCT116 , Humanos , Solubilidade , Comprimidos , Difração de Raios X/métodosRESUMO
Marine sponges of the genusSuberea produce variety of brominated tyrosine alkaloids which display diverse range of biological activities including antiproliferative, antimicrobial and antimalarial activities. In continuation of our search for biologically active marine natural products for antibacterial compounds, we report here the synthesis and evaluation of biological activity of panel of ianthelliformisamines and subereamine analogues using the literature known acid-amine coupling reaction. Several derivatives of Ianthelliformisamine were achieved by the coupling of Boc-protected polyamine chain with brominated aromatic acrylic acid derivatives by varying the bromine substituents on aromatic acid derivatives, amine spacer as well as geometry of the double bond, and then Boc-deprotection using TFA. Similarly, subereamine analogues were also synthesized employing coupling reaction between various brominated phenyl acrylic acids with commercially available chiral amino ester derivatives followed by ester hydrolysis. We screened these synthetic analogues for antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) strains. One of the compound 7c showed bactericidal activity against Staphylococcus aureus with an IC50 value of 3.8 µM (MIC = 25 µM).
Assuntos
Antibacterianos/farmacologia , Arginina/análogos & derivados , Produtos Biológicos/farmacologia , Escherichia coli/efeitos dos fármacos , Hidrocarbonetos Bromados/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Tirosina/análogos & derivados , Antibacterianos/síntese química , Antibacterianos/química , Arginina/síntese química , Arginina/química , Arginina/farmacologia , Produtos Biológicos/síntese química , Produtos Biológicos/química , Relação Dose-Resposta a Droga , Escherichia coli/crescimento & desenvolvimento , Células HEK293 , Humanos , Hidrocarbonetos Bromados/síntese química , Hidrocarbonetos Bromados/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Staphylococcus aureus/crescimento & desenvolvimento , Relação Estrutura-Atividade , Tirosina/síntese química , Tirosina/química , Tirosina/farmacologiaRESUMO
In this study, glimepiride and l-arginine (GA) binary mixtures at various molar ratios were prepared to evaluate whether they could improve the poor water solubility and dissolution characteristics of glimepiride. It was shown that glimepiride and arginine form a eutectic mixture, a type of crystalline solid dispersions, at a 1:1 M ratio and eutectic temperature of 426.9 K using a phase diagram constructed using differential scanning calorimetry (DSC) and thermo-microscopy. The preserved characteristic powder X-ray diffraction (PXRD) patterns and infrared (IR) spectra of each material in those of GA binary mixtures confirmed the formation of eutectic mixture without molecular interaction in solid state. The formation of GA eutectic mixture (GAEM) resulted in the improvement of solubility through pH modification and the intermolecular interaction of glimepiride and l-arginine in aqueous mediums, thereby wettability and dissolution rate of glimepiride were also enhanced. The intermolecular interaction between glimepiride and l-arginine at a 1:1 stoichiometry of the complex in solution state was identified by phase solubility, stoichiometric determination, and solution state nuclear magnetic resonance (NMR) spectroscopy. Specific molecular interactions such as hydrogen bonding and hydrophobic interaction were suggested as main mechanisms of GA complexation in solution. Therefore, this study concludes that the GAEM could be an effective way to improve the solubility and dissolution rate of glimepiride.
Assuntos
Arginina/síntese química , Arginina/metabolismo , Química Farmacêutica/métodos , Compostos de Sulfonilureia/síntese química , Compostos de Sulfonilureia/metabolismo , Solubilidade , Difração de Raios X/métodosRESUMO
Designing novel 18F-labeled amino acid derivatives for targeted amino acid transporters is an attractive strategy for the development of therapeutic and diagnostic agents for cancer therapy. In this work, we have developed a novel 3-fluoropropyl analog of arginine, namely, (2S,4S)4-[18F]FPArg, [18F]1, to be used as a probe for studying arginine metabolism. Optically pure and labeled with 18F and 19F, (2S,4S)4-(3-fluoropropyl)arginine was synthesized and isolated in high radiochemical purity (>95%). In vitro uptake assays in human MCF-7â¯cells revealed that [18F]1 enters cells mainly via sodium-independent cationic amino acid transporters and was inhibited >62% by arginine. [18F]1 showed a high cellular uptake of 7.3⯱â¯0.24% and 6.07⯱â¯0.3% uptake/100â¯mg protein after incubation in MCF-7 and MDA-MB-231â¯cells for 120â¯min, respectively. In vivo biodistribution studies demonstrated that [18F]1 provided high tumor uptake and high tumor to muscle ratios (5:1â¯at the 30 and 60â¯min time points). In vivo PET imaging studies demonstrated tumor-specific uptake in nude mice bearing MCF-7 breast tumors with an excellent tumor-to-muscle ratio. These results suggest that [18F]1 is a promising tracer for clinical breast cancer imaging and may be used to diagnose and monitor diseases that are associated with arginine metabolism.
Assuntos
Arginina/análogos & derivados , Arginina/síntese química , Neoplasias da Mama/diagnóstico por imagem , Radioisótopos de Flúor/química , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/síntese química , Animais , Arginina/metabolismo , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Estabilidade de Medicamentos , Feminino , Humanos , Camundongos Nus , Estrutura Molecular , Compostos Radiofarmacêuticos/metabolismo , Relação Estrutura-Atividade , Distribuição TecidualRESUMO
A novel biotin and arginine modified hydroxypropyl-ß-cyclodextrin (biotin-Arg(pbf)-HP-ß-CD) was successfully synthesized. The hydroxyl groups of HP-ß-CD on the primary faces were coupled with carboxyl groups of biotin using arginine as the functional spacer. Using biotin-Arg(pbf)-HP-ß-CD as the carrier, paclitaxel (PTX)-loaded nanoparticles were developed by modified emulsion solvent evaporation method. The optimized PTX-loaded biotin-Arg(pbf)-HP-ß-CD nanoparticles had a mean diameter of 121.9 nm and zeta potential of -57.7 mV. Transmission electron microscopy (TEM) observation revealed that the nanoparticles were spherical in shape. XRD spectra confirmed the successful encapsulation of PTX. Moreover, in vitro and in vivo evaluations were performed to demonstrate the superior antitumor activity of the PTX-loaded nanoparticles. The cellular uptake study demonstrated the biotin receptor-mediated endocytosis of biotin-Arg(pbf)-HP-ß-CD nanoparticles and the increase of cellular uptake by introduction of biotin and arginine. It can be concluded that the biotin-Arg(pbf)-HP-ß-CD nanoparticles are efficient tumor-targeting drug delivery systems for PTX.
Assuntos
2-Hidroxipropil-beta-Ciclodextrina/química , Antineoplásicos/uso terapêutico , Portadores de Fármacos/química , Nanopartículas/química , Paclitaxel/uso terapêutico , 2-Hidroxipropil-beta-Ciclodextrina/síntese química , 2-Hidroxipropil-beta-Ciclodextrina/toxicidade , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Arginina/análogos & derivados , Arginina/síntese química , Arginina/toxicidade , Biotina/análogos & derivados , Biotina/síntese química , Biotina/toxicidade , Carcinoma/tratamento farmacológico , Portadores de Fármacos/síntese química , Portadores de Fármacos/toxicidade , Feminino , Humanos , Células MCF-7 , Camundongos , Nanopartículas/toxicidade , Paclitaxel/química , Paclitaxel/farmacologia , Tamanho da Partícula , Neoplasias do Colo do Útero/tratamento farmacológico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND/AIM: We investigated the inhibitory action of medium molecular weight heparinyl phenylalanine (MHF) on type I hypersensitivity in comparison with medium molecular weight heparinyl arginine (MHR). MATERIALS AND METHODS: MHF and MHR were synthesized from heparin (HE) to decrease the side-effect of HE based on its anticoagulant action and used in this study. RESULTS: MHF demonstrated a significant inhibitory action on 48-h homologous passive cutaneous anaphylaxis in rats. Although MHF did not affect the death of mice injected with a lethal dose of histamine, it significantly prolonged the survival time of mice administered a lethal dose of compound 48/80. On the other hand, MHR did not inhibit type I hypersensitivity. CONCLUSION: The inhibitory action of MHF on the type I allergic reaction was due to a reduction or delay in histamine release from mast cells. MHF may be a potent anti-allergic agent.
Assuntos
Anticoagulantes/administração & dosagem , Histamina/toxicidade , Hipersensibilidade Imediata/tratamento farmacológico , Fenilalanina/administração & dosagem , Anafilaxia/sangue , Anafilaxia/tratamento farmacológico , Anafilaxia/patologia , Animais , Anticoagulantes/síntese química , Anticoagulantes/química , Arginina/administração & dosagem , Arginina/síntese química , Arginina/química , Modelos Animais de Doenças , Heparina/síntese química , Heparina/química , Hipersensibilidade Imediata/sangue , Hipersensibilidade Imediata/patologia , Masculino , Mastócitos/efeitos dos fármacos , Camundongos , Peso Molecular , Fenilalanina/síntese química , Fenilalanina/química , RatosRESUMO
In this study, chitosan/poly(ethylene oxide) (PEO)/lauric arginate (LAE) composite nanofibrous films were fabricated via electrospinning. The addition of LAE did not change the physical properties of chitosan/PEO in acetic aqueous solutions, but increased the fluorescent intensity of chitosan by electrostatic interactions, resulting in uniform and bead-free nanofibers with an average diameter of 150 nm. The Fourier transform infrared spectra and thermal analysis indicated that the LAE molecules were homogeneously dispersed within the chitosan/PEO nanofibers. The formation of electrostatic and hydrogen bonding interactions induced by the LAE addition changed the inter- and intramolecular interactions between PEO and chitosan and further affected the mobility of the polymer molecules, leading to the increased crystallinity and decreased melting point. The hydrophilicity of the nanofibrous films was significantly increased by the incorporation of LAE, as indicated by the decreasing water contact angle from 39° to 10°. Meanwhile, the chitosan/PEO/LAE nanofibrous films showed LAE concentration dependent antimicrobial activity against Escherichia coli and Staphylococcus aureus, suggesting enhanced antimicrobial activity. The fluorescent staining experiments demonstrated that the antimicrobial mechanism of the nanofibrous films was cell membrane damage.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Arginina/análogos & derivados , Embalagem de Alimentos/instrumentação , Nanofibras/química , Polietilenoglicóis/farmacologia , Antibacterianos/química , Arginina/síntese química , Arginina/química , Arginina/farmacologia , Quitosana/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Interações Hidrofóbicas e Hidrofílicas , Nanofibras/toxicidade , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Polímeros/síntese química , Polímeros/química , Polímeros/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Eletricidade EstáticaRESUMO
A chiral ligand exchange capillary electrochromatography (CLE-CEC) protocol was designed and implemented for d,l-amino acids enantioseparation with poly(maleic anhydride-styrene-methacryloyl-l-arginine methyl ester) as the coating. The block copolymer was synthesized through the reversible addition fragmentation chain transfer reaction. In the constructed CLE-CEC system, poly (methacryloyl-l-arginine methyl ester) moiety of the block copolymer played the role as the immobilized chiral ligand and Zn (II) was used as the central ion. Key factors, including pH of buffer solution, ratio of Zn (II) to ligands, the mass ratio of monomers in the block copolymer, which affect the enantioresolution were investigated. Comparing with the bare capillary, the CLE-CEC enantioresolution was enhanced greatly with the coating one. 5 Pairs of d,l-amino acids enantiomers obtained baseline separation with 5 pairs partly separated. The mechanism of enhancement enantioresolution of the developed CLE-CEC system was explored briefly. Further, good linearities were achieved in the range of 25.0⯵M-5.0â¯mM for quantitative analysis of d-glutamine (r2â¯=â¯0.997) and l-glutamine (r2â¯=â¯0.991). Moreover, the proposed CLE-CEC assay was successfully applied in the kinetics study of glutaminase by using l-glutamine as the substrate.
Assuntos
Aminoácidos/análise , Eletrocromatografia Capilar/métodos , Glutaminase/metabolismo , Aminoácidos/química , Arginina/análogos & derivados , Arginina/síntese química , Arginina/química , Soluções Tampão , Concentração de Íons de Hidrogênio , Cinética , Ligantes , EstereoisomerismoRESUMO
Agonism of the 5-HT2C receptor represents one of the most well-studied and clinically proven mechanisms for pharmacological weight reduction. Selectivity over the closely related 5-HT2A and 5-HT2B receptors is critical as their activation has been shown to lead to undesirable side effects and major safety concerns. In this communication, we report the development of a new screening paradigm that utilizes an active site mutant D134A (D3.32) 5-HT2C receptor to identify atypical agonist structures. We additionally report the discovery and optimization of a novel class of nonbasic heterocyclic amide agonists of 5-HT2C. SAR investigations around the screening hits provided a diverse set of potent agonists at 5-HT2C with high selectivity over the related 5-HT2A and 5-HT2B receptor subtypes. Further optimization through replacement of the amide with a variety of five- and six-membered heterocycles led to the identification of 6-(1-ethyl-3-(quinolin-8-yl)-1H-pyrazol-5-yl)pyridazin-3-amine (69). Oral administration of 69 to rats reduced food intake in an ad libitum feeding model, which could be completely reversed by a selective 5-HT2C antagonist.
Assuntos
Arginina/análogos & derivados , Flavonas/química , Receptor 5-HT2C de Serotonina/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Arginina/síntese química , Arginina/química , Arginina/farmacologia , Encéfalo/metabolismo , Células CACO-2 , Permeabilidade da Membrana Celular , Comportamento Alimentar/efeitos dos fármacos , Flavonas/síntese química , Flavonas/farmacologia , Células HEK293 , Humanos , Masculino , Membranas Artificiais , Camundongos Knockout , Microssomos Hepáticos/metabolismo , Mutação , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2B de Serotonina/metabolismo , Receptor 5-HT2C de Serotonina/genética , Agonistas do Receptor 5-HT2 de Serotonina/síntese química , Agonistas do Receptor 5-HT2 de Serotonina/farmacocinética , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Relação Estrutura-AtividadeRESUMO
A new series of semisynthetic flavone-based small molecules mimicking antimicrobial peptides has been designed from natural icaritin to combat drug-resistant Gram-positive bacterial infections. Compound 6 containing two arginine residues exhibited excellent antibacterial activity against Gram-positive bacteria, including MRSA, and very low toxicity to mammalian cells, resulting in a high selectivity of more than 511, comparable to that of several membrane-active antibiotics in clinical trials. Our data show for the first time that icaritin derivatives effectively kill bacteria. Meanwhile, this is the first study deploying a biomimicking strategy to design potent flavone-based membrane targeting antimicrobials. 6 showed rapid bactericidal activity by disrupting the bacterial membrane and can circumvent the development of bacterial resistance. Importantly, 6 was highly efficacious in a mouse model of corneal infection caused by MRSA and Staphylococcus aureus.
Assuntos
Antibacterianos/síntese química , Arginina/análogos & derivados , Flavonas/síntese química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Arginina/síntese química , Arginina/farmacologia , Arginina/toxicidade , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Sobrevivência Celular , Farmacorresistência Bacteriana , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Flavonas/farmacologia , Flavonas/toxicidade , Hemólise , Humanos , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Mimetismo Molecular , Coelhos , Staphylococcus aureus , Relação Estrutura-AtividadeRESUMO
Hyperpolarization enhances the intensity of the NMR signals of a molecule, whose in vivo metabolic fate can be monitored by MRI with higher sensitivity. SABRE is a hyperpolarization technique that could potentially be used to image nitric oxide (NO) production in vivo. This would be very important, because NO dysregulation is involved in several pathologies, including cardiovascular ones. The nitric oxide synthase (NOS) pathway leads to NO production via conversion of l-arginine into l-citrulline. NO is a free radical gas with a short half-life in vivo (≈5s), therefore direct NO quantification is challenging. An indirect method - based on quantifying conversion of an l-Arg- to l-Cit-derivative by 1H NMR spectroscopy - is herein proposed. A small library of pyridyl containing l-Arg derivatives was designed and synthesised. In vitro tests showed that compounds 4a-j and 11a-c were better or equivalent substrates for the eNOS enzyme (NO2- production=19-46µM) than native l-Arg (NO2- production=25µM). Enzymatic conversion of l-Arg to l-Cit derivatives could be monitored by 1H NMR. The maximum hyperpolarization achieved by SABRE reached 870-fold NMR signal enhancement, which opens up exciting future perspectives of using these molecules as hyperpolarized MRI tracers in vivo.
Assuntos
Arginina/síntese química , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico/metabolismo , Animais , Arginina/análogos & derivados , Arginina/metabolismo , Biocatálise , Bovinos , Espectroscopia de Ressonância Magnética , Óxido Nítrico/análise , Óxido Nítrico Sintase Tipo III/química , Óxido Nítrico Sintase Tipo III/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Especificidade por SubstratoRESUMO
UNLABELLED: L-Arginine is an a-amino acid which plays important roles in different diseases or processes, such as Alzheimer disease, inflammatory process, healing and tissue regeneration and it also could be useful as an anti-atherosclerotic agent. AIM: Considering the large amount of studies on the beneficial effects of different antioxidants, this paper is focused on the evaluation of the antioxidant potential of some imine derivatives, synthesized by the authors and described in a previous article. MATERIAL AND METHODS: The evaluation of the antioxidant power was performed using phosphomolydenum-reducing antioxidant power (PRAP) and ferric reducing antioxidant power (FRAP) assays, tests described in the literature and which are used with some minor modifications. RESULTS: It was found that most of the imine derivatives are more active than the L-Arginine in the PPAP and FRAP assays. The most active derivative was the compound obtained by condensation of L-arginine with 2,3-dihydroxybenzaldehyde (2k) and 2-nitrobenzaldehyde (2g). CONCLUSIONS: Following the described protocol, some imine derivatives of L-arginine were evaluated in terms of antioxidant potential using in vitro methods. The most favorable influence was obtained by the aromatic substitution with nitro and hydroxyl, the corresponding derivatives being the most active derivatives compared to L-arginine.
Assuntos
Antioxidantes/farmacologia , Arginina/síntese química , Benzaldeídos/síntese química , Catecóis/síntese química , Avaliação Pré-Clínica de Medicamentos , Iminas/farmacologia , Antioxidantes/síntese química , Avaliação Pré-Clínica de Medicamentos/métodos , Iminas/síntese química , Técnicas In VitroRESUMO
Naturally occurring N(ω)-hydroxy-l-arginine (NOHA, 1) is the best substrate of NO synthases (NOS). The development of stable and bioavailable prodrugs would provide a pharmacologically valuable strategy for the treatment of cardiovascular diseases that are associated with endothelial dysfunction. To improve NOHAs druglike properties, we demonstrate that O-substitution by (glycosylic) acetal formation greatly increased the chemical stability of the hydroxyguanidine moiety and provided a nontoxic group that could be easily bioactivated by glycosidases. A straightforward synthetic concept was devised and afforded a series of diversely substituted prodrugs by O-conjugation of the hydroxyguanidine moiety with different monosaccharides. Systematic exploration of their bioactivation profile revealed that glucose-based prodrugs were more efficiently bioactivated than their galactose counterparts. NOS-dependent cytosolic NO release was quantified by automated fluorescence microscopy in a cell-based assay with murine macrophages. Glucose-based prodrugs performed particularly well and delivered cellular NO levels comparable to 1, demonstrating proof-of-concept.
Assuntos
Arginina/análogos & derivados , Doadores de Óxido Nítrico/química , Pró-Fármacos/química , Animais , Arginina/síntese química , Arginina/química , Arginina/farmacologia , Linhagem Celular , Desenho de Fármacos , Galactose/química , Glucose/química , Glicosilação , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/síntese química , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/metabolismo , Pró-Fármacos/síntese química , Pró-Fármacos/farmacologia , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Water-soluble prodrug strategy is a practical alternative for improving the drug bioavailability of sparingly-soluble drugs with reduced drug efficacy. Many water-soluble prodrugs of sparingly-soluble drugs, such as the phosphate ester of a drug, have been reported. Recently, we described a novel water-soluble prodrug based on O-N intramolecular acyl migration. However, these prodrug approaches require a hydroxy group in the structure of their drugs, and other prodrug approaches are often restricted by the structure of the parent drugs. To develop prodrugs with no restriction in the structure, we focused on a decomposition reaction of arginine methyl ester. This reaction proceeds at room temperature under neutral conditions, and we applied this reaction to the prodrug strategy for drugs with an amino group. We designed and synthesized novel prodrugs of representative sparingly soluble drugs phenytoin and sulfathiazole. Phenytoin and sulfathiazole were obtained as stable salt that were converted to parent drugs under physiological conditions. Phenytoin prodrug 3 showed a short half-life (t1/2) of 13min, whereas sulfathiazole prodrug 7 had a moderate t1/2 of 40min. Prodrugs 3 and 7 appear to be suitable for use as an injectable formulation and orally administered drug, respectively.
Assuntos
Anti-Infecciosos/química , Anticonvulsivantes/química , Guanidina/química , Fenitoína/química , Pró-Fármacos/química , Sulfatiazóis/química , Anti-Infecciosos/síntese química , Anticonvulsivantes/síntese química , Arginina/análogos & derivados , Arginina/síntese química , Arginina/química , Estabilidade de Medicamentos , Fenitoína/síntese química , Pró-Fármacos/síntese química , Solubilidade , Sulfatiazol , Sulfatiazóis/síntese química , Água/químicaRESUMO
Protein phosphorylation is one of the most common and extensively studied post-translational modifications (PTMs). Compared to the O-phosphorylation on Ser, Thr and Tyr residues, our understanding of arginine phosphorylation is relatively limited, both in prokaryotes and eukaryotes, due to the intrinsic instability of phosphoarginine (pArg) and the lack of a feasible method to produce anti-pArg antibodies. We report the design and synthesis of a stable pArg analog, in which the labile N-P bond is replaced with a non-hydrolyzable C-P bond. Significantly, this analog was successfully used as a hapten to raise an immune response and the first mouse polyclonal antibody that specifically recognizes pArg-containing peptides and proteins was produced using analog-KLH conjugated as the immunogen. The generated antibody shows excellent specificity towards pArg-containing peptides and proteins, and could be used for a variety of biological detection methods. This provides us an invaluable tool to unravel the mystery of the biological function of pArg.
Assuntos
Anticorpos/imunologia , Arginina/análogos & derivados , Animais , Anticorpos/química , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/imunologia , Antígenos/química , Antígenos/imunologia , Arginina/síntese química , Arginina/química , Arginina/imunologia , Desenho de Fármacos , Camundongos , Estrutura Molecular , Compostos Organofosforados/síntese química , Compostos Organofosforados/química , Compostos Organofosforados/imunologia , Peptídeos/química , Peptídeos/imunologia , Proteínas/química , Proteínas/imunologiaRESUMO
Porcine pancreatic carboxypeptidase B (EC 3.4.23.6) was complexed with a stable transition-state analogue, N-sulfamoyl-L-arginine, in which an S atom imitates the sp(3)-hybridized carbon in the scissile-bond surrogate. Crystals were grown in a form belonging to the same space group, P41212, as the uncomplexed enzyme. X-ray data were collected to a resolution of 1.25â Å. The molecule was refined and the positions of non-H atoms of the inhibitor and water molecules were defined using difference Fourier maps. The enzyme-inhibitor complex and 329 water molecules were further refined to a crystallographic R factor of 0.159. The differences in conformation between the complexed and uncomplexed forms of carboxypeptidase B are shown. The inhibitor is bound in a curved conformation in the active-site cleft, and the sulfamide group is bound to the Zn ion in an asymmetric bidentate fashion. The complex is stabilized by hydrogen bonds between the N1/N2 guanidine group of the inhibitor and the Asp255 carboxyl of the enzyme. The side-chain CH2 groups of the inhibitor are in van der Waals contact with Leu203 and Ile247 in the enzyme. This study provides useful clues concerning how the transition state of arginine may bind to carboxypeptidase B and therefore provides an insight into the structural basis of carboxypeptidase B selectivity, which is useful for the rational design of a carboxypeptidase with improved selectivity for industrial recombinant pro-insulin processing.
Assuntos
Arginina/análogos & derivados , Arginina/química , Carboxipeptidase B/química , Sulfonamidas/química , Animais , Arginina/síntese química , Domínio Catalítico , Cristalização , Cristalografia por Raios X , Ligação de Hidrogênio , Ligantes , Soluções , Eletricidade Estática , Sulfonamidas/síntese química , Sus scrofaRESUMO
Compounds 10 (ND-322) and 15 (ND-364) are potent selective inhibitors for gelatinases, matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9). However, both of them are racemates. Herein we report facile synthesis of optically active (R)- and (S)-enantiomers of compounds 10 and 15. And the sulfonyl of 15 was transformed to sulfinyl to obtain four epimeric mixtures. All synthesized thiirane-based compounds were evaluated in MMP2 and MMP9 inhibitory assays. Our results indicated that the configuration of thiirane moiety had little effects on gelatinase inhibition, but the substitution of sulfinyl for sulfonyl was detrimental to gelatinase inhibition. Besides, all target compounds exhibited no inhibition against other two Zn(2+) dependant metalloproteases, aminopeptidase N (APN) and histone deacetylases (HDACs), which confirmed the unique Zn(2+) chelation mechanism of thiirane moiety against gelatinases.
Assuntos
Arginina/análogos & derivados , Gelatinases/antagonistas & inibidores , Inibidores de Metaloproteinases de Matriz/farmacologia , Éteres Fenílicos/farmacologia , Sulfonas/farmacologia , Arginina/síntese química , Arginina/química , Arginina/farmacologia , Relação Dose-Resposta a Droga , Gelatinases/metabolismo , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Inibidores de Metaloproteinases de Matriz/síntese química , Inibidores de Metaloproteinases de Matriz/química , Estrutura Molecular , Éteres Fenílicos/síntese química , Éteres Fenílicos/química , Relação Estrutura-Atividade , Sulfonas/síntese química , Sulfonas/químicaRESUMO
We report a selective ruthenium catalyzed reduction of tertiary amides on the side chain of Fmoc-Gln-OtBu derivatives, leading to innovative unnatural α,ß or γ-amino acids functionalized with tertiary amines. Rapid and scalable, this process allowed us to build a library of basic unnatural amino acids at the gram-scale and directly usable for liquid- or solid-phase peptide synthesis. The diversity of available tertiary amines allows us to modulate the physicochemical properties of the resulting amino acids, such as basicity or hydrophobicity.
Assuntos
Aminas/química , Aminoácidos/síntese química , Arginina/análogos & derivados , Lisina/análogos & derivados , Ornitina/análogos & derivados , Técnicas de Síntese em Fase Sólida/métodos , Amidas/química , Aminas/síntese química , Aminoácidos/química , Arginina/síntese química , Catálise , Lisina/síntese química , Ornitina/síntese química , Oxirredução , Rutênio/química , Técnicas de Síntese em Fase Sólida/economiaRESUMO
Two novel arginine-based cationic surfactants were synthesized using as biocatalyst papain, an endopeptidase from Carica papaya latex, adsorbed onto polyamide. The classical substrate N (α)-benzoyl-arginine ethyl ester hydrochloride for the determination of cysteine and serine proteases activity was used as the arginine donor, whereas decyl- and dodecylamine were used as nucleophiles for the condensation reaction. Yields higher than 90 and 80 % were achieved for the synthesis of N (α)-benzoyl-arginine decyl amide (Bz-Arg-NHC10) and N (α)-benzoyl-arginine dodecyl amide (Bz-Arg-NHC12), respectively. The purification process was developed in order to make it more sustainable, by using water and ethanol as the main separation solvents in a single cationic exchange chromatographic separation step. Bz-Arg-NHC10 and Bz-Arg-NHC12 proved antimicrobial activity against both Gram-positive and Gram-negative bacteria, revealing their potential use as effective disinfectants as they reduced 99 % the initial bacterial population after only 1 h of contact. The cytotoxic effect towards different cell types of both arginine derivatives was also measured. Bz-Arg-NHCn demonstrated lower haemolytic activity and were less eye-irritating than the commercial cationic surfactant cetrimide. A similar trend could also be observed when cytotoxicity was tested on hepatocytes and fibroblast cell lines: both arginine derivatives were less toxic than cetrimide. All these properties would make the two novel arginine compounds a promising alternative to commercial cationic surfactants, especially for their use as additives in topical formulations.
Assuntos
Antibacterianos/farmacologia , Arginina/análogos & derivados , Arginina/farmacologia , Tensoativos/farmacologia , Antibacterianos/síntese química , Antibacterianos/isolamento & purificação , Arginina/síntese química , Arginina/isolamento & purificação , Biocatálise , Sobrevivência Celular/efeitos dos fármacos , Cromatografia por Troca Iônica , Eritrócitos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Hemólise , Células Hep G2 , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Papaína/química , Tensoativos/síntese química , Tensoativos/isolamento & purificaçãoRESUMO
Aiming at molecular tools for the neuropeptide Y Y1 receptor (Y1 R), three types of derivatives of the argininamide-type Y1 R antagonist BIBO3304 were prepared by (i) propionylation at the guanidine group (3), (ii) substitution at the urea moiety with a propionamidobutyl residue (4), and (iii) replacement of ureidomethyl by a propionylaminomethyl group (5). With Ki and Kb values in the range of 1.5-4.3 nM, determined in binding and functional assays, and high selectivity for the Y1 R over the Y2 R, Y4 R, and Y5 R, compounds 4 and 5 were identified as promising candidates for radiolabeling by [(3) H]propionylation according to established protocols.