Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
ACS Appl Mater Interfaces ; 13(38): 45149-45160, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34520182

RESUMO

The removal of uremic toxins from patients with acute kidney injury is a key issue in improving the quality of life for people requiring peritoneal dialysis. The currently utilized method for the removal of uremic toxins from the human organism is hemodialysis, performed on semipermeable membranes where the uremic toxins, along with small molecules, are separated from proteins and blood cells. In this study, we describe a mixed-linker modulated synthesis of zirconium-based metal-organic frameworks for efficient removal of uremic toxins. We determined that the efficient adsorption of uremic toxins is achieved by optimizing the ratio between -amino functionalization of the UiO-66 structure with 75% of -NH2 groups within organic linker structure. The maximum adsorption of hippuric acid and 3-indoloacetic acid was achieved by UiO-66-NH2 (75%) and by UiO-66-NH2 (75%) 12.5% HCl prepared by modulated synthesis. Furthermore, UiO-66-NH2 (75%) almost completely adsorbs 3-indoloacetic acid bound to bovine serum albumin, which was used as a model protein to which uremic toxins bind in the human body. The high adsorption capacity was confirmed in recyclability test, which showed almost 80% removal of 3-indoloacetic acid after the third adsorption cycle. Furthermore, in vitro cytotoxicity tests as well as hemolytic activity assay have proven that the UiO-66-based materials can be considered as potentially safe for hemodialytic purposes in living organisms.


Assuntos
Hipuratos/isolamento & purificação , Ácidos Indolacéticos/isolamento & purificação , Rins Artificiais , Estruturas Metalorgânicas/química , Ácidos Ftálicos/química , Toxinas Urêmicas/isolamento & purificação , Adsorção , Animais , Chlorocebus aethiops , Eritrócitos/efeitos dos fármacos , Células HEK293 , Hipuratos/química , Humanos , Ácidos Indolacéticos/química , Estruturas Metalorgânicas/síntese química , Estruturas Metalorgânicas/toxicidade , Ácidos Ftálicos/síntese química , Ácidos Ftálicos/toxicidade , Toxinas Urêmicas/química , Células Vero , Zircônio/química
2.
World J Microbiol Biotechnol ; 37(9): 159, 2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34420104

RESUMO

Botrytis cinerea, the causal agent of gray mold is one of the major devastating fungal pathogens that occurs in strawberry cultivation and leads to massive losses. Due to the rapid emergence of resistant strains in recent years, an ecofriendly disease management strategy needs to be developed to control this aggressive pathogen. Bacillus velezensis CE 100 exhibited strong antagonistic activity with 53.05% against B. cinerea by dual culture method. In the present study, 50% of culture filtrate supplemented into PDA medium absolutely inhibited mycelial growth of B. cinerea whereas the highest concentration (960 mg/L) of different crude extracts including ethyl acetate, chloroform, and n-butanol crude extracts of B. velezensis CE 100, strongly inhibited mycelial growth of B. cinerea with the highest inhibition of 79.26%, 70.21% and 69.59% respectively, resulting in severe damage to hyphal structures with bulging and swellings. Hence, the antifungal compound responsible was progressively separated from ethyl acetate crude extract using medium pressure liquid chromatography. The purified compound was identified as methyl hippurate by nuclear magnetic resonance and mass spectrometry. The inhibitory effect of methyl hippurate on both spore germination and mycelial growth of B. cinerea was revealed by its dose-dependent pattern. The spore germination rate was completely restricted at a concentration of 3 mg/mL of methyl hippurate whereas no mycelial growth was observed in agar medium supplemented with 4 mg/mL and 6 mg/mL of methyl hippurate by poisoned food method. Microscopic imaging revealed that the morphologies of spores were severely altered by long-time exposure to methyl hippurate at concentrations of 1 mg/mL, 2 mg/mL and 3 mg/mL and hyphae of B. cinerea were severely deformed by exposure to methyl hippurate at concentrations of 2 mg/mL, 4 mg/mL and 6 mg/mL. No significant inhibition on tomato seed germination was observed in treatments with methyl hippurate (2 mg/mL) for both 6 h and 12 h soaking period as compared to the controls. Based on these results, B. velezensis CE 100 could be considered a potential agent for development of environmentally friendly disease control strategies as a consequence of the synergetic interactions of diverse crude metabolites and methyl hippurate.


Assuntos
Bacillus/química , Botrytis/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Hipuratos/farmacologia , Bacillus/metabolismo , Botrytis/crescimento & desenvolvimento , Fungicidas Industriais/química , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/metabolismo , Hipuratos/química , Hipuratos/isolamento & purificação , Hipuratos/metabolismo , Hifas/efeitos dos fármacos , Hifas/crescimento & desenvolvimento , Solanum lycopersicum/microbiologia , Doenças das Plantas/microbiologia , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento
3.
Artigo em Inglês | MEDLINE | ID: mdl-32240053

RESUMO

Salicylates are among the most known anti-inflammatory drugs, used both in human and veterinary medicine. They also occur naturally in plants. Residues of salicylic acid in tissues and eggs may occur after drug administration or exposure of animals to feed material with high salicylate content. An animal study was performed on laying hens. The birds received sodium salicylate or acetylsalicylic acid (10 mg/kg b.w.) for 7 days or were given corn containing 1.18 mg/kg of salicylic acid. Samples of liver, muscle and plasma were collected at 0, 4, 8, 24 and 72 h after treatment; eggs were collected daily for 14 days. Salicylic acid and its metabolites: gentisic acid, salicyluric acid and gentisuric acid were determined using liquid chromatography coupled with tandem mass spectrometry. In both liver and muscle, the residues after administration of sodium salicylate were initially higher than for acetylsalicylic acid but they depleted at the same time. The deposition and depletion profile of salicylic acid in eggs was similar for groups receiving both drugs; the plateau level reached 248 ± 61.5 µg/kg and 275 ± 82.1 µg/kg. The concentration of salicylic acid in tissues and eggs of animals receiving salicylic acid was low. Gentisic acid was found in individual samples of liver, muscle and eggs from all treated groups. The exposure of hens to the salicylates at feed additive levels and to naturally occurring salicylates results in low residue concentrations and fast depletion of salicylic acid. The eggs do not pose any risk to consumers sensitive to salicylates.


Assuntos
Resíduos de Drogas/análise , Análise de Alimentos , Contaminação de Alimentos/análise , Hipuratos/química , Óvulo/química , Ácido Salicílico/análise , Administração Oral , Animais , Galinhas , Hipuratos/administração & dosagem , Fígado/química , Músculos/química , Ácido Salicílico/administração & dosagem , Ácido Salicílico/metabolismo
4.
Bioorg Chem ; 97: 103640, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32086051

RESUMO

Inhibitors of aldose reductase are rate-limiting enzymes and could play a key role to prevent the complications of diabetes. In our attempt to develop novel inhibitors of aldose reductase, the derivatives of rhodanine-3-hippuric acid-pyrazole hybrid were synthesized and characterised by spectral data. The biological studies reveal that all the compounds show an excellent activity against ALR2 with IC50 values ranging from 0.04 to 1.36 µM. Among these the synthesised compounds 6a-m, 6g and 6e showed specific inhibitory activity with IC50 values of 0.04 and 0.06 µM respectively against ALR2 and found to be more potent than epalrestat (IC50 = 0.87 µM), the only aldose reductase inhibitor currently used in the therapy. Molecular docking analysis using the AR-NADP+ complex as a receptor was performed with all the synthesized compounds. All the compounds exhibit a well-defined binding mode within the AR active site, similarly to previous described AR inhibitors, with the anion head group bound to the catalytic center, blocking thus its activity. By forming hydrogen bonds with Tyr48 and His110 of the protein from ALR2 (PDB ID: 2FZD), the compounds 6g and 6e interrupt the proton donation mechanism, which is necessary for the catalytic activity of ALR2.


Assuntos
Aldeído Redutase/antagonistas & inibidores , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Rodanina/análogos & derivados , Rodanina/farmacologia , Aldeído Redutase/química , Aldeído Redutase/metabolismo , Desenho de Fármacos , Descoberta de Drogas , Hipuratos/química , Hipuratos/farmacologia , Humanos , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade
5.
Carbohydr Res ; 487: 107887, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31830633

RESUMO

A new practical utility for ß-stereoselective L-rhamnopyranosylations are conducted using rhamnosyl trichloroacetimidate donors in the presence of N-benzoylglycine/thiourea cooperative catalysis. This method represents the first instance where amino acid derivative N-benzoylglycine is used as a catalyst for ß-L-rhamnopyranosylations. This method represents the first instance where environmentally benign amino acid derivative, such as N-benzoylglycine which is reported as less toxic and can be used as efficient catalyst for smooth transformation under eco friendly conditions. On the other hand ß-stereoselectivity of rhamnosyl trichloroacetimidate donors protected with O-picoloyl groups at remote positions (C-2 and C-3) has been investigated while the glycosylation reactions of 2-O-picoloyl group substituted l-rhamnosyl donor displays predominant ß-stereoselectivity. Reaction proceeded smoothly with moderate to high yield under mild reaction conditions at room temperature with 10 mol% catalyst loadings and tolerant of a wide range of glycoside acceptors.


Assuntos
Hipuratos/química , Tioureia/química , Glicosilação , Estrutura Molecular , Estereoisomerismo
6.
ACS Appl Mater Interfaces ; 11(47): 43843-43856, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31663727

RESUMO

Protein-bound uremic toxins (PBUTs) can cause noxious effects in patients suffering from renal failure as a result of inhibiting the transport of proteins and inducing their structural modification. They are difficult to remove through standard hemodialysis (HD) treatment. Herein, we report an organic bioelectronic HD device system for the effective removal of PBUTs through electrically triggered dissociation of protein-toxin complexes. To prepare this system, we employed electrospinning to fabricate electrically conductive quaternary composite nanofiber mats-comprising multiwalled carbon nanotubes (MWCNTs), poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS), poly(ethylene oxide) (PEO), and (3-glycidyloxypropyl)trimethoxysilane (GOPS)-on conventional polyethersulfone (PES) dialysis membranes. These composite nanofiber platforms exhibited (i) long-term water resistance (due to cross-linking among PSS, PEO, and GOPS), (ii) high adhesion strength on the PES membrane (due to GOPS functioning as an adhesion promoter), (iii) enhanced electrical properties [due to the MWCNTs and PEDOT:PSS promoting effective electrical stimulation (ES) operation in devices containing bioelectronic interfaces (BEI)], and (iv) good anticoagulant ability and negligible hemolysis of red blood cells. We employed this organic BEI electronic system as a novel single-membrane HD device to study the removal efficiency of four kinds of uremic toxins [p-cresol (PC), indoxyl sulfate, and hippuric acid as PBUTs; creatinine as a non-PBUT] as well as the effects of ES on lowering the protein binding ratio. Our organic BEI devices provided a high rate of removal of PC with low protein loss after 4 h of a simulated dialysis process. It also functioned with low complement activation, low contact activation levels, and lower amounts of platelet adsorption, suggesting great suitability for use in developing next-generation bioelectronic medicines for HD.


Assuntos
Nanotubos de Carbono/química , Proteínas/química , Diálise Renal/instrumentação , Toxinas Biológicas/química , Uremia/terapia , Adsorção , Cresóis/sangue , Cresóis/química , Eletrônica/instrumentação , Hipuratos/sangue , Hipuratos/química , Humanos , Indicã/sangue , Indicã/química , Polímeros/química , Toxinas Biológicas/sangue , Uremia/sangue
7.
Talanta ; 199: 290-295, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30952260

RESUMO

A chitosan membrane composed by 60% (w/w) chitosan and 40% (w/w) Aliquat®336 has been proposed as a new biopolymeric support for electromembrane extraction. The new support has been characterized by Scanning Electron Microscopy, resulting a 30-35 µm thickness. Amoxicillin, nicotinic acid, hippuric acid, salicylic acid, anthranilic acid, ketoprofen, naproxen and ibuprofen have been successfully extracted using the proposed support. Better enrichment factors were obtained for the acidic polar analytes than for the non-steroidal anti-inflammatory compounds (ranging from 118 for hippuric acid and 20 for ibuprofen). Electromembrane extraction was developed applying a DC voltage of 100 V, 1-octanol as supported liquid membrane and 20 min of extraction. The target analytes have also been satisfactorily extracted from human urine samples, providing high extraction efficiencies. The chitosan membrane is presented as a promising alternative for supporting liquid membrane compared to commonly used materials for this purpose.


Assuntos
Biopolímeros/química , Quitosana , Técnicas Eletroquímicas , Amoxicilina/química , Amoxicilina/isolamento & purificação , Hipuratos/química , Hipuratos/isolamento & purificação , Humanos , Ibuprofeno/química , Ibuprofeno/isolamento & purificação , Cetoprofeno/química , Cetoprofeno/isolamento & purificação , Naproxeno/química , Naproxeno/isolamento & purificação , Niacina/química , Niacina/isolamento & purificação , Ácido Salicílico/química , Ácido Salicílico/isolamento & purificação , ortoaminobenzoatos/química , ortoaminobenzoatos/isolamento & purificação
8.
Mini Rev Med Chem ; 19(9): 708-719, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30058483

RESUMO

In this review, specific therapeutic and medicinal advantages including antiviral, antibacterial, antifungal and antitumor, strategies for drug designing, structure-activity relationship, advances in the syntheses of azo and hippuric acid derivatives of more than 50 compounds have been discussed since 2009-2018. It is found that phenyl-diazenyl azo derivatives and pyridinyl substituted hippuric acid derivatives showed promising antiretroviral potential. The incorporation of azo functionality to the respective quinolones and coumarin moieties and the insertion of thiocarbazone to hippuric acid displayed immense antibacterial activities. While, azo and hippuric acid derivatives of triazole and phenyl species gave maximum fungicidal as well as cytotoxic activities.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Compostos Azo/química , Compostos Azo/farmacologia , Hipuratos/química , Hipuratos/farmacologia , Animais , Anti-Infecciosos/síntese química , Antineoplásicos/síntese química , Compostos Azo/síntese química , Infecções Bacterianas/tratamento farmacológico , Desenho de Fármacos , Hipuratos/síntese química , Humanos , Micoses/tratamento farmacológico , Neoplasias/tratamento farmacológico , Relação Estrutura-Atividade , Viroses/tratamento farmacológico
9.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 75(Pt 4): 750-762, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32830731

RESUMO

In order to comprehend the binding of an important metabolite, hippuric acid, with human serum albumin and to understand its chemical and electronic nature, an experimental charge-density analysis has been carried out using high-resolution diffraction data collected under cryogenic conditions, and all the results have been compared with theoretical findings using the B3LYP/6-311++g(2d,2p) level of theory. The structure displays very strong classical hydrogen bonds as well as other noncovalent interactions, which have been fully characterized using Hirshfeld surface analysis and Bader's quantum theory of atoms in molecules. Contact analysis on the Hirshfeld surfaces shows that the O...H, C...H and C...N intermolecular interactions are enriched and gives their relative strengths. Topological analysis of the electron density shows the charge concentration/depletion of hippuric acid bonds in the crystal structure. Electrostatic parameters such as atomic charges and dipole moments were calculated. The mapping of atomic basins and the calculation of respective charges show the atomic volumes of each atom as well as their charge contributions in the hippuric acid crystal structure. The dipole-moment calculations show that the molecule is very polar in nature. Calculations of the electrostatic potential show that the chain part of the molecule has a higher concentration of negative charge than the ring, which might be instrumental in its strong binding with the polar residues of site II of human serum albumin.


Assuntos
Hipuratos/química , Hipuratos/metabolismo , Albumina Sérica Humana/metabolismo , Sítios de Ligação , Fenômenos Químicos , Cristalização , Cristalografia por Raios X , Elétrons , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Ligação Proteica , Eletricidade Estática
10.
Chem Commun (Camb) ; 55(8): 1020-1023, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30452037

RESUMO

We describe covalently binding modulators of the activity of human prolyl hydroxylase domain 2 (PHD2) and studies towards a strategy for photocapture of PHD2 substrates. Reversible active site binding of electrophile bearing compounds enables susbsequent covalent reaction with a lysine residue (K408) in the flexible C-terminal region of PHD2 to give a modified protein that retains catalytic activity.


Assuntos
Inibidores Enzimáticos/metabolismo , Hipuratos/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Azidas/química , Azidas/efeitos da radiação , Catálise , Domínio Catalítico , Inibidores Enzimáticos/química , Células HeLa , Hipuratos/química , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/antagonistas & inibidores , Prolina Dioxigenases do Fator Induzível por Hipóxia/química , Ligantes , Lisina/química , Ligação Proteica , Raios Ultravioleta
11.
J Sep Sci ; 41(2): 501-508, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29082608

RESUMO

In the current study, a novel technique for extraction and determination of trans,trans-muconic acid, hippuric acid, and mandelic acid was developed by means of ion-pair-based hollow fiber liquid-phase microextraction in the three-phase mode. Important factors affecting the extraction efficiency of the method were investigated and optimized. These metabolites were extracted from 10 mL of the source phase into a supported liquid membrane containing 1-octanol and 10% w/v of Aliquat 336 as the ionic carrier followed by high-performance liquid chromatography analysis. The organic phase immobilized in the pores of a hollow fiber was back-extracted into 24 µL of a solution containing 3.0 mol/L sodium chloride placed inside the lumen of the fiber. A very high preconcentration of 212- to 440-fold, limit of detection of 0.1-7 µg/L, and relative recovery of 87-95% were obtained under the optimized conditions of this method. The relative standard deviation values for within-day and between-day precisions were calculated at 2.9-8.5 and 4.3-11.2%, respectively. The method was successfully applied to urine samples from volunteers at different work environments. The results demonstrated that the method can be used as a sensitive and effective technique for the determination of the metabolites in urine.


Assuntos
Benzeno/análise , Cromatografia Líquida de Alta Pressão , Estireno/urina , Tolueno/urina , 1-Octanol/química , Hipuratos/química , Humanos , Concentração de Íons de Hidrogênio , Íons , Limite de Detecção , Microextração em Fase Líquida , Ácidos Mandélicos/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Solventes , Ácido Sórbico/análogos & derivados , Ácido Sórbico/química , Espectrofotometria Ultravioleta , Temperatura , Urinálise
12.
Molecules ; 22(12)2017 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-29206156

RESUMO

Cyanobacteria are able to produce a wide range of secondary metabolites, including toxins and protease inhibitors, with diverse biological activities. Microginins are small linear peptides biosynthesized by cyanobacteria species that act against proteases. The aim of this study was to isolate and identify microginins produced by the LTPNA08 strain of Microcystis aeruginosa, as well as to verify their potential to inhibit angiotensin-converting enzyme (ACE; EC. 3.4.15.1) using in vitro and in silico methods. The fractionation of cyanobacterial extracts was performed by liquid chromatography and the presence of microginins was monitored by both LC-MS and an ACE inhibition assay. Enzyme inhibition was assayed by ACE with hippuryl-histidyl-leucine as the substrate; monitoring of hippuric acid was performed by HPLC-DAD. Isolated microginins were confirmed by mass spectrometry and were used to carry out the enzymatic assay. Molecular docking was used to evaluate microginin 770 (MG 770) and captopril (positive control), in order to predict similar binding interactions and determine the inhibitory action of ACE. The enzyme assay confirmed that MG 770 can efficiently inhibit ACE, with an IC50 equivalent to other microginins. MG 770 presented with comparable interactions with ACE, having features in common with commercial inhibitors such as captopril and enalaprilate, which are frequently used in the treatment of hypertension in humans.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Anti-Hipertensivos/química , Proteínas de Bactérias/química , Microcystis/química , Peptidil Dipeptidase A/química , Inibidores de Proteases/química , Inibidores da Enzima Conversora de Angiotensina/isolamento & purificação , Anti-Hipertensivos/isolamento & purificação , Proteínas de Bactérias/isolamento & purificação , Sítios de Ligação , Ensaios Enzimáticos , Hipuratos/química , Humanos , Microcystis/metabolismo , Simulação de Acoplamento Molecular , Oligopeptídeos/química , Inibidores de Proteases/isolamento & purificação , Ligação Proteica , Conformação Proteica , Especificidade por Substrato
13.
J Korean Med Sci ; 32(12): 2051-2057, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29115090

RESUMO

To determine the relationship between the oral ingestion volume of xylene and methyl hippuric acid (MHA) in urine, we measured MHA in 11 patients whose ingested xylene volume was identified. The best-fit equation between urine MHA and ingested amount of xylene was as follows: y (ingested amount of xylene, mL/kg) = -0.052x² + 0.756x (x = MHA in urine in g/g creatinine). From this equation, we estimated the ingested xylene volume in 194 patients who had ingested pesticide of which the formulation was not available. Our results demonstrated that oxadiazole, dinitroaniline, chloroacetamide, organophosphate, and pyrethroid were xylene-containing pesticide classes, while the paraquat, glyphosate, glufosinate, synthetic auxin, fungicide, neonicotinoid, and carbamate classes were xylene-free pesticides. Sub-group univariate analysis showed a significant association between MHA levels in urine and ventilator necessity in the pyrethroid group. However, this association was not observed in the organophosphate group. Our results suggest that MHA in urine is a surrogate marker for xylene ingestion, and high urine MHA levels may be a risk factor for poor clinical outcome with some pesticide poisoning.


Assuntos
Hipuratos/urina , Praguicidas/intoxicação , Xilenos/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Cromatografia Líquida de Alta Pressão , Feminino , Hipuratos/química , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/patologia , Fatores de Risco , Índice de Gravidade de Doença , Centros de Atenção Terciária , Ventiladores Mecânicos , Xilenos/intoxicação
14.
J Pharm Biomed Anal ; 138: 109-117, 2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-28192718

RESUMO

Acetylsalicylic acid (Aspirin, ASA) is a famous drug for cardiovascular diseases in recent years. Effects of ASA dosage on the metabolic profile have not been fully understood. The purpose of our study is to establish a rapid and reliable method to quantify ASA metabolites in biological matrices, especially for glucuronide metabolites whose standards are not commercially available. Then we applied this method to evaluate the effects of ASA dosage on the metabolic and excretion profile of ASA metabolites in rat urine. Salicylic acid (SA), gentisic acid (GA) and salicyluric acid (SUA) were determined directly by UHPLC-MS/MS, while salicyl phenolic glucuronide (SAPG) and salicyluric acid phenolic glucuronide (SUAPG) were quantified indirectly by measuring the released SA and SUA from SAPG and SUAPG after ß-glucuronidase digestion. SUA and SUAPG were the major metabolites of ASA in rat urine 24h after ASA administration, which accounted for 50% (SUA) and 26% (SUAPG). When ASA dosage was increased, the contributions dropped to 32% and 18%, respectively. The excretion of other three metabolites (GA, SA and SAPG) however showed remarkable increases by 16%, 6% and 4%, respectively. In addition, SUA and SUAPG were mainly excreted in the time period of 12-24h, while GA was excreted in the earlier time periods (0-4h and 4-8h). SA was mainly excreted in the time period of 0-4h and 12-24h. And the excretion of SAPG was equally distributed in the four time periods. We went further to show that the excretion of five metabolites in rat urine was delayed when ASA dosage was increased. In conclusion, we have developed a rapid and sensitive method to determine the five ASA metabolites (SA, GA, SUA, SAPG and SUAPG) in rat urine. We showed that ASA dosage could significantly influence the metabolic and excretion profile of ASA metabolites in rat urine.


Assuntos
Aspirina/metabolismo , Aspirina/urina , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Aspirina/química , Glucuronatos/química , Glucuronatos/urina , Glucuronidase/química , Glucuronídeos/química , Glucuronídeos/urina , Hipuratos/química , Hipuratos/urina , Masculino , Metaboloma/fisiologia , Ratos , Ratos Sprague-Dawley , Salicilatos/química , Salicilatos/urina , Ácido Salicílico/química , Ácido Salicílico/urina
15.
Sensors (Basel) ; 17(1)2016 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-28036064

RESUMO

In this study, a homogeneous method featuring simple, one-step detection was developed to analyze hippuric acid (HA), a major metabolite of toluene. High sensitivity was achieved with the facile immobilization of poly(vinylimidazole) (PVI) on an indium tin oxide (ITO) electrode. Using a previously developed approach, pentacyanoferrate was coordinated with pyridyl-N ligands, and the redox-active Fe(II/III) centers were bound to Ni(II) ions on the electrode via electrostatic cyanide bridges. The detection was accomplished by the competitive binding of free HA and pentacyanoferrate-(4-aminomethylpyridine-hippuric acid) (Fe-HA, the electron transfer mediator) to the HA antibody on the Ni(II) ions-modified PVI-ITO (Ni-PVI-ITO) electrode. The electrical and physicochemical characterization of the electrode was carried out by cyclic voltammetry, differential pulse voltammetry, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy. At low mediator concentrations, the electrical signals were proportional to the HA concentration between 0.1 µg/mL and 1.0 mg/mL. The same method may be extended to other small organic molecules.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Hipuratos/química , Imunoensaio/métodos , Oxirredução , Espectroscopia Fotoeletrônica/métodos
16.
J Med Chem ; 59(12): 5847-56, 2016 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-27232368

RESUMO

Multidrug resistance-associated protein 4 (MRP4) and organic anion transporter 3 (OAT3) mediate the efflux of organic anions from the brain and heart. In this study, we have developed a probe for estimating the activity of these transporters in these tissues using positron emission tomography. Several (11)C-labeled hippuric acid ester derivatives were screened with the expectation that they would be hydrolyzed in situ to form the corresponding (11)C-labeled organic acids in target tissues. Among the compounds screened, benzyl [(11)C]hippurate showed favorable hydrolysis rates and uptake properties in the target tissues of mice. Subsequent evaluation using transporter knockout mice revealed that radioactivity was retained in the brain and heart of Oat3(-/-) and Mrp4(-/-) mice, respectively, compared with that of control mice after the intravenous administration of benzyl [(11)C]hippurate. Benzyl [(11)C]hippurate could therefore be used as a probe for estimating the activities of OAT3 and MRP4 in mouse brain and heart, respectively.


Assuntos
Encéfalo/metabolismo , Hipuratos/farmacocinética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Administração Intravenosa , Animais , Radioisótopos de Carbono , Coração , Hipuratos/administração & dosagem , Hipuratos/síntese química , Hipuratos/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas à Resistência a Múltiplos Medicamentos/deficiência , Transportadores de Ânions Orgânicos Sódio-Independentes/deficiência , Tomografia por Emissão de Pósitrons , Distribuição Tecidual
17.
ACS Comb Sci ; 17(8): 452-8, 2015 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-26145510

RESUMO

In this article, an original one-pot method is utilized to synthesize a variety of derivatives of naphtho[2,1-b]furan-2(1H)-one via a pseudo-four-component domino reaction of aryl aldehydes, acetic anhydride, hippuric acids, and 2-naphthols catalyzed by HSW@SPIONs. This reaction illustrates an array of attractive features including, with particular interest in this report, a convenient and unique process of creating and utilizing a powerful recyclable nanocatalyst.


Assuntos
Anidridos Acéticos/química , Aldeídos/química , Hipuratos/química , Lactonas/síntese química , Nanopartículas de Magnetita/química , Naftalenos/síntese química , Naftóis/química , Óxidos/química , Dióxido de Silício/química , Compostos de Tungstênio/química , Catálise , Lactonas/química , Estrutura Molecular , Naftalenos/química
18.
J Labelled Comp Radiopharm ; 58(1): 14-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25545452

RESUMO

The objective of this study was to evaluate four new (68) Ga-labeled 1,4,7,10-cyclododeca-1,4,7,10-tetraacetic acid (DOTA)/1,4,7-triazacyclononane-1,4,7-triacetic acid derived (NODAGA)-glycine/hippurate conjugates and select a lead candidate for potential application in positron emission tomography (PET) renography. The non-metallated conjugates were synthesized by a solid phase peptide synthesis method. The (68) Ga labeling was achieved by reacting an excess of the non-metallated conjugate with (68) GaCl4 (-) at pH -4.5 and 10-min incubation either at room temperature for NODAGA or 90 °C for DOTA. Radiochemical purity of all (68) Ga conjugates was found to be >98%. (68) Ga-NODAGA-glycine displayed the lowest serum protein binding (0.4%) in vitro among the four (68) Ga conjugates. Biodistribution of (68) Ga conjugates in healthy Sprague Dawley rats at 1-h post-injection revealed an efficient clearance from circulation primarily through the renal-urinary pathway with <0.2% of injected dose per gram remaining in the blood. The kidney/blood and kidney/muscle ratios of (68) Ga-NODAGA-glycine were significantly higher than other (68) Ga conjugates. On the basis of these results, (68) Ga-NODAGA-glycine was selected as the lead candidate. (68) Ga-NODAGA-glycine PET renograms obtained in healthy rats suggest (68) Ga-NODAGA-glycine as a PET alternate of (99m) Tc-Diethylenetriaminepentaacetic acid (DTPA).


Assuntos
Complexos de Coordenação/farmacocinética , Glicina/análogos & derivados , Glicina/química , Compostos Heterocíclicos com 1 Anel/farmacocinética , Hipuratos/química , Tomografia por Emissão de Pósitrons , Renografia por Radioisótopo , Compostos Radiofarmacêuticos/farmacocinética , Acetatos/química , Animais , Complexos de Coordenação/síntese química , Feminino , Glicina/síntese química , Glicina/farmacocinética , Compostos Heterocíclicos com 1 Anel/síntese química , Compostos Heterocíclicos com 1 Anel/química , Compostos Radiofarmacêuticos/síntese química , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
19.
Sensors (Basel) ; 14(10): 18886-97, 2014 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-25313491

RESUMO

By directly coordinating hippuric acid (HA) to the ferrate (Fe) as an electron transfer mediator, we synthesized a Fe-HA complex, which shows a good electrochemical signal and thus enables the electrochemical immunoanalysis for HA. We electrodeposited organic films containing imidazole groups on the electrode surface and then bonded Ni ion (positive charge) to induce immobilization of Fe-HA (negative charge) through the electrostatic interaction. The heterogeneous competitive immunoassay system relies on the interaction between immobilized Fe-HA antigen conjugate and free HA antigen to its antibody (anti-HA). The electric signal becomes weaker due to the hindered electron transfer reaction when a large-sized HA antibody is bound onto the Fe-HA. However, in the presence of HA, the electric signal increases because free HA competitively reacts with the HA antibody prior to actual reaction and thus prevents the HA antibody from interacting with Fe-HA at the electrode surface. This competition reaction enabled an electrochemical quantitative analysis of HA concentration with a detection limit of 0.5 µg mL(-1), and thus allowed us to develop a simple and rapid electrochemical immunosensor.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Hipuratos/isolamento & purificação , Imunoensaio/métodos , Ferro/química , Anticorpos/química , Anticorpos/imunologia , Antígenos/imunologia , Antígenos/isolamento & purificação , Hipuratos/química , Hipuratos/imunologia , Humanos , Limite de Detecção , Níquel/química , Tolueno/química
20.
J Pharm Biomed Anal ; 92: 98-104, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24503197

RESUMO

Hydrophilic interaction chromatography-mass spectrometry (HILIC-MS) was used for anionic metabolic profiling of urine from antibiotic-treated rats to study microbial-host co-metabolism. Rats were treated with the antibiotics penicillin G and streptomycin sulfate for four or eight days and compared to a control group. Urine samples were collected at day zero, four and eight, and analyzed by HILIC-MS. Multivariate data analysis was applied to the urinary metabolic profiles to identify biochemical variation between the treatment groups. Principal component analysis found a clear distinction between those animals receiving antibiotics and the control animals, with twenty-nine discriminatory compounds of which twenty were down-regulated and nine up-regulated upon treatment. In the treatment group receiving antibiotics for four days, a recovery effect was observed for seven compounds after cessation of antibiotic administration. Thirteen discriminatory compounds could be putatively identified based on their accurate mass, including aconitic acid, benzenediol sulfate, ferulic acid sulfate, hippuric acid, indoxyl sulfate, penicillin G, phenol and vanillin 4-sulfate. The rat urine samples had previously been analyzed by capillary electrophoresis (CE) with MS detection and proton nuclear magnetic resonance ((1)H NMR) spectroscopy. Using CE-MS and (1)H NMR spectroscopy seventeen and twenty-five discriminatory compounds were found, respectively. Both hippuric acid and indoxyl sulfate were detected across all three platforms. Additionally, eight compounds were observed with both HILIC-MS and CE-MS. Overall, HILIC-MS appears to be highly complementary to CE-MS and (1)H NMR spectroscopy, identifying additional compounds that discriminate the urine samples from antibiotic-treated and control rats.


Assuntos
Ânions/química , Ânions/urina , Antibacterianos/farmacologia , Urina/química , Animais , Cromatografia Líquida/métodos , Eletroforese Capilar/métodos , Hipuratos/química , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética/métodos , Masculino , Espectrometria de Massas/métodos , Metaboloma/efeitos dos fármacos , Metabolômica/métodos , Penicilina G/química , Análise de Componente Principal/métodos , Ratos , Ratos Wistar , Estreptomicina/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...