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1.
Molecules ; 26(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34299653

RESUMO

The formation of most multicomponent crystals relies on the interaction of hydrogen bonds between the components, so rational crystal design based on the expected hydrogen-bonded supramolecular synthons was employed to establish supramolecular compounds with desirable properties. This theory was put into practice for metformin to participate in more therapeutic fields to search for a fast and simple approach for the screening of candidate crystal co-formers. The prediction of intermolecular synthons facilitated the successful synthesis of a new multicomponent crystal of metformin (Met) and barbital (Bar) through an anion exchange reaction and cooling crystallization method. The single crystal X-ray diffraction analysis demonstrated the hydrogen bond-based ureide/ureide and guanidine/ureide synthons were responsible for the self-assembly of the primary structural motif and extended into infinite supramolecular heterocatemeric structures.


Assuntos
Barbital/química , Metformina/química , Modelos Moleculares , Cristalografia por Raios X , Ligação de Hidrogênio , Estrutura Molecular
2.
J Am Coll Nutr ; 38(5): 415-423, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30696389

RESUMO

Objective: Tea (Camellia sinensis Linn.; family: Theaceae) is popular as a stimulant beverage across the globe and is also utilized as a functional antioxidant in alternative medicine. This study has evaluated the impact of seasonal variation on phyto-constituents of tea. Method: The antiproliferative potential of methanolic extracts of tea leaves collected in the rainy season (MECR) was compared with the extract of tea leaves collected in the autumn season (MECA) of the same mother plant. Evaluation of in vivo antitumor activity was carried out in adult female Swiss albino mice groups inoculated with Ehrlich ascites carcinoma (EAC) cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to compare efficacy of MECR with that of MECA in the EAC cell line. Both qualitative and quantitative tests for phytochemical constituents present in MECA and MECR were performed. Antitumor efficacy of both the extracts was determined by evaluating different tumor markers showing dose-dependent cytotoxicity. Results: Statistically significant reduction in EAC-induced tumor was observed in MECR treated mice compared to MECA treated ones. Cell decimation was significantly higher with MECR treatment, where restoration of different parameters including tissue structures returned to normal. Moreover, gas chromatography-mass spectrometry (GC-MS) study revealed the presence of cyclobarbital and benzazulene derivative in MECR, which is thought to be a novel source of these chemicals. Conclusions: To our knowledge, there is no report that has attempted to reveal nutritional changes in terms of efficacy and variation in anticancer constituents in tea leaves, plucked in two seasons. This study revealed a novel source of barbital and benzazulene derivative. The unique presence of cyclobarbital and benzazulene, as revealed from GC-MS data, in methanolic extract of tea leaves collected during the rainy season (MECR) may have contributed to its enhanced in vitro (adopting MTT assay) and in vivo (on EAC-infected Swiss albino mice) cytotoxicity vis-à-vis antiproliferative properties compared to methanolic extract of tea leaves collected during the autumn season (MECA). The nature of plucking leaves in the two selected seasons is different.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Metanol/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Chá/química , Animais , Antineoplásicos Fitogênicos/química , Barbital/farmacologia , Camellia sinensis , Carcinoma de Ehrlich , Linhagem Celular Tumoral , Feminino , Metanol/química , Camundongos , Extratos Vegetais/química , Estações do Ano
3.
J Phys Chem A ; 122(11): 3031-3044, 2018 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-29481082

RESUMO

Experimental charge density distribution studies, complemented by quantum mechanical theoretical calculations, of a host-guest system composed of a macrocycle (1) and barbital (2) in a 1:1 ratio (3) have been carried out via high-resolution single-crystal X-ray diffraction. The data were modeled using the conventional multipole model of electron density according to the Hansen-Coppens formalism. The asymmetric unit of macrocycle 1 contained an intraannular ethanol molecule and an extraannular acetonitrile molecule, and the asymmetric unit of 3 also contained an intraannular ethanol molecule. Visual comparison of the conformations of the macrocyclic ring shows the rotation by 180° of an amide bond attributed to competitive hydrogen bonding. It was found that the intraannular and extraannular molecules inside were orientated to maximize the number of hydrogen bonds present, with the presence of barbital in 3 resulting in the greatest stabilization. Hydrogen bonds ranging in strength from 4 to 70 kJ mol-1 were the main stabilizing force. Further analysis of the electrostatic potential among 1, 2, and 3 showed significant charge redistribution when cocrystallization occurred, which was further confirmed by a comparison of atomic charges. The findings presented herein introduce the possibility of high-resolution X-ray crystallography playing a more prominent role in the drug design process.


Assuntos
Barbital/química , Compostos Macrocíclicos/química , Teoria Quântica , Sítios de Ligação , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular
4.
Int J Pharm ; 493(1-2): 434-8, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26253375

RESUMO

The effect of salt formulation on the electrostatic property of active pharmaceutical ingredients was investigated. The electrostatic property of weak acids (carboxylic acids and amide-enole type acid) and their sodium salts was evaluated by a suction-type Faraday cage meter. Free carboxylic acids showed negative chargeability, whereas their sodium salts showed more positive chargeability than the free acids. However, no such trend was observed for amide-enole type acids.


Assuntos
Ácidos Carboxílicos/química , Barbital/química , Química Farmacêutica , Dantroleno/química , Omeprazol/química , Sais/química , Eletricidade Estática
5.
Chem Asian J ; 9(10): 2831-41, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25080369

RESUMO

In our previous paper, we reported that a dimeric Zn(2+) complex with a 2,2'-bipyridyl linker (Zn2L(1)), cyanuric acid (CA), and a Cu(2+) ion automatically assemble in aqueous solution to form 4:4:4 complex 3, which selectively catalyzes the hydrolysis of mono(4-nitrophenyl)phosphate (MNP) at neutral pH. Herein, we report that the use of barbital (Bar) instead of CA for the self-assembly with Zn2L(1) and Cu(2+) induces 2:2:2 complexation of these components, and not the 4:4:4 complex, to form supramolecular complex 6 a, the structure and equilibrium characteristics of which were studied by analytical and physical measurements. The finding show that 6 a also accelerates the hydrolysis of MNP, similarly to 3. Moreover, inspired by the crystal structure of 6 a, we prepared barbital units that contain functional groups on their side chains in an attempt to produce supramolecular phosphatases that possess functional groups near the Cu2(µ-OH)2 catalytic core so as to mimic the catalytic center of alkaline phosphatase (AP).


Assuntos
Barbital/química , Cobre/química , Compostos Heterocíclicos/química , Zinco/química , Cristalografia por Raios X , Espectrofotometria Ultravioleta , Água/química
6.
Mol Pharm ; 11(1): 338-50, 2014 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-24283960

RESUMO

Barbital is a hypnotic agent that has been intensely studied for many decades. The aim of this work was to establish a clear and comprehensible picture of its polymorphic system. Four of the six known solid forms of barbital (denoted I(0), III, IV, and V) were characterized by various analytical techniques, and the thermodynamic relationships between the polymorph phases were established. The obtained data permitted the construction of the first semischematic energy/temperature diagram for the barbital system. The modifications I(0), III, and V are enantiotropically related to one another. Polymorph IV is enantiotropically related to V and monotropically related to the other two forms. The transition points for the pairs I(0)/III, I(0)/V, and III/IV lie below 20 °C, and the transition point for IV/V is above 20 °C. At room temperature, the order of thermodynamic stability is I(0) > III > V > IV. The metastable modification III is present in commercial samples and has a high kinetic stability. The solid-state NMR spectra provide information on aspects of crystallography (viz., the asymmetric units and the nature of hydrogen bonding). The known correlation between specific N-H···O═C hydrogen bonding motifs of barbiturates and certain IR characteristics was used to predict the H-bonded pattern of polymorph IV.


Assuntos
Barbital/química , Cristalização , Varredura Diferencial de Calorimetria , Cristalografia por Raios X , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Termodinâmica , Difração de Raios X
8.
Artigo em Inglês | MEDLINE | ID: mdl-23220533

RESUMO

Copper guanine and barbital complexes were prepared and characterized by elemental analyses and spectral measurements. The data typified the formation of stoichiometries 1:1 (M:L) with possible Cu-Cu interaction "association". The complexes are with different geometries: square planar, square pyramidal and tetrahedral. The mode of bonding was identified by IR spectra. EPR spectra of the powdered complexes were recorded at X band at the room temperature. Different ESR parameters were calculated and discussed: g(//), g(⊥), A(//), [g], G, F, K, α(2). Molecular modeling techniques and quantum chemical methods have been performed for copper complexes to correlate the chemical structures of the complexes with their physical molecular properties. Bond lengths, bond orders, bond angles, dihedral angles, close contact, dipole moment (µ), sum of the total negative charge (STNC), electronegativity (χ), chemical potential (Pi), global hardness (η), softness (σ), the highest occupied molecular orbital energy (E(HOMO)), the lowest unoccupied molecular orbital energy (E(LUMO)) and the energy gap (ΔE) were calculated using PM3 semi-empirical and Molecular Mechanics (MM+) methods. The study displays a good correlation between the theoretical and experimental data which confirms the reliability of the quantum chemical methods.


Assuntos
Barbital/química , Complexos de Coordenação/química , Cobre/química , Guanina/química , Espectroscopia de Ressonância de Spin Eletrônica , Modelos Moleculares , Teoria Quântica , Espectrofotometria Infravermelho
9.
Se Pu ; 29(11): 1082-6, 2011 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-22393695

RESUMO

A simple, precise and sensitive gas chromatography-mass spectrometry (GC-MS) method coupled with pulse splitless injection technique was developed for the determination of 10 sedative-hypnotics (barbital, amobarbital, phenobarbital, oxazepam, diazepam, nitrazepam, clonazepam, estazolam, alprazolam, triazolam) in human plasma. The drugs spiked in plasma were extracted with ethyl acetate after alkalization with 0.1 mol/L NaOH solution. The organic solvent was evaporated under nitrogen stream, and the residues were redissolved by ethyl acetate. The separation was performed on an HP-5MS column (30 m x 250 microm x 0.25 microm). The analytes were determined and identified using selected ion monitoring (SIM) mode and scan mode, respectively. The internal standard method was used for the determination. The target analytes were well separated from each other on their SIM chromatograms and also on the total ion current (TIC) chromatograms. The blank extract from human plasma gave no peaks that interfered with all the analytes on the chromatogram. The calibration curves for 10 sedative-hypnotics showed excellent linearity. The correlation coefficients of all the drugs were higher than 0.9954. The recoveries of the drugs spiked in human plasma ranged from 92.28% to 111.7%, and the relative standard deviations (RSDs) of intra-day and inter-day determinations were from 4.09% to 14.26%. The detection limits ranged from 2 to 20 microg/L. The method is simple, reliable, rapid and sensitive for the determination and the quantification of 10 sedative-hypnotics in human plasma and seems to be useful in the practice of clinical toxicological cases.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Hipnóticos e Sedativos/sangue , Barbital/sangue , Estazolam/sangue , Humanos , Oxazepam/sangue
10.
Anal Chim Acta ; 679(1-2): 1-6, 2010 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-20951851

RESUMO

A rapid method for sensitive ultraviolet detection of multiple psychotropic drugs in human plasma was developed on a low-cost and expediently fabricated hybrid microfluidic device. The device was composed of one fused-silica capillary with a sampling fracture, a poly(methyl methacrylate) board with four reservoirs, and a printed circuit board. At the optimal separation and detection conditions, the baseline separation of three kinds of psychotropic drugs including barbiturates (phenobarbital and barbital), benzodiazepines (nitrazepam, clonazepam, chlordiazepoxide, alprazolam and diazepam) and tricyclic antidepressant drugs (amitriptyline) was achieved within 200 s with separation efficiency up to 3.80 × 10(5) plates m(-1). The linear ranges for ultraviolet detection were from 2.0 to 1000.0 µg mL(-1) for chlordiazepoxide and 1.0 to 1000.0 µg mL(-1) for other seven drugs. Combining with solid-phase extraction, this novel protocol could successfully be used to screen naturally existing psychotropic drugs in a known human plasma sample. The minimum detectable concentration was down to 27 ng mL(-1) for phenobarbital spiked in plasma. This work provided a promising way to initially screen different psychotropic drugs with high resolution, rapid separation and low-cost.


Assuntos
Eletroforese em Microchip/instrumentação , Eletroforese em Microchip/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Psicotrópicos/sangue , Amitriptilina/sangue , Barbital/sangue , Benzodiazepinas/sangue , Equipamentos Descartáveis , Desenho de Equipamento , Feminino , Humanos , Limite de Detecção , Masculino , Fenobarbital/sangue , Fotometria , Reprodutibilidade dos Testes , Extração em Fase Sólida
11.
J Phys Chem A ; 114(34): 9237-45, 2010 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-20681553

RESUMO

A computational study of the structural and thermochemical properties of N-phenyl (open) and N-alkyl (cyclic) ureas, through the use of M05-2X and B3LYP density functional theory calculations has been carried out. The consistency of the literature experimental results has been confirmed, and using mainly isodesmic reactions, the unknown Delta(f)H(0)(g) of the other urea derivatives were estimated. The experimental results together with the theoretical information have permitted the study of the effect of phenyl, p- and m-chlorophenyl, alkyl, and carbonyl substitutions on the thermodynamical stability of urea and its cyclic derivatives. The peculiar behavior of the N-tert-butyl substituent in cyclic ureas has been related to geometric deformations.


Assuntos
Barbital/química , Carbanilidas/química , Hidantoínas/química , Imidazolidinas/química , Compostos de Metilureia/química , Teoria Quântica , Temperatura , Ureia/química , Modelos Moleculares , Conformação Molecular , Compostos de Fenilureia/química , Termodinâmica
12.
Se Pu ; 28(1): 23-33, 2010 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-20458916

RESUMO

A rapid method for the simultaneous determination of 42 psychoactive drugs and their metabolites (barbitals, benzodiazepines, tricyclic antidepressants, phenothiazines, etc. ) in human plasma and urine was developed using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). After a simple protein precipitation step, the analysis of the drugs and the metabolites was achieved on an Acquity UPLC BEH C18 column by using the gradient elution with ammonium acetate and methanol-acetonitrile (1: 1, v/v) as the mobile phases, and detected by electrospray ionization-tandem mass spectrometry in the multiple reaction monitoring (MRM) mode operated simultaneously in both positive and negative modes by rapid switching, and quantified by matrix-match standard solution. The average recoveries were 60.2% - 125% and 64.5% - 126% for the drugs in plasma and urine except those of perphenazine, thioridazine and chloropromazine in plasma were 37.6% - 57.5%, 36.3% - 48.3%, 52.4% -67.4%, respectively; trazodone and diazepam in urine were 100% -142% and 108% - 177%, respectively. The relative standard deviations (RSDs) of all the drugs in plasma and urine were within 0.8% - 26% and 2.6%18% (n = 6), respectively. The detection limits of the 4 barbitals ranged from 20 to 100 mg/L and those of the other drugs ranged from 0.05 to 2.0 mg/L. The method is simple, selective and sensitive to detect drugs for both clinical and forensic purposes.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Psicotrópicos/sangue , Psicotrópicos/urina , Espectrometria de Massas em Tandem/métodos , Antidepressivos Tricíclicos/sangue , Antidepressivos Tricíclicos/urina , Barbital/sangue , Barbital/urina , Benzodiazepinas/sangue , Benzodiazepinas/urina , Análise Química do Sangue/métodos , Humanos , Psicotrópicos/metabolismo
13.
J Chromatogr A ; 1217(17): 2821-31, 2010 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-20227703

RESUMO

This work describes a liquid chromatography-tandem mass spectrometry (LC-MS/MS) procedure for multiplex screening, ultratrace quantification and reliable confirmation of barbital series residues in animal-derived food matrices. The method is developed based on a distinct dependency of the electrospray ionization (ESI) response of nine structural homologues on LC eluent properties and gas-phase ion chemistry during the ESI process. The "wrong-way-round" negative ionization aspect has been explored to optimize the compatibility of the hyphenated LC-MS/MS technique, which facilitates detection limits at 30-100-fold lower than 0.01 ppm without derivatization or post-column basification step. A mobile phase using methanol modified with 0.01% acetic acid is adopted to achieve an approximately 2-9-fold increase in signal-to-noise ratio over the results under suboptimal conditions. There is no significant differential matrix effects or deuterium isotope effects on chromatographic retention and ESI responsiveness at all levels across the different analyte-matrix pairs. Mean recoveries ranged from 79.6% (barbital) to 108% (secobarbital) at fortified levels of 0.5-20 ng/g within relative standard deviations less than 11%. Between-run repeatability and within-laboratory reproducibility were 3-11% and 5-13%, respectively. An ion ratio criterion for valid detection limit data for simultaneous screening of homologous multiresidues in complex sample matrices is proposed. The satisfactory applicability of the newly described procedure to 43 real samples including pork, poultry meat, swine liver, fish tissue and shrimp muscle demonstrated the LC-MS/MS technique with facile sample handling can serve as an attractive alternative analytical method accepted for regulatory purpose.


Assuntos
Barbital/análise , Cromatografia Líquida/métodos , Resíduos de Drogas/análise , Carne/análise , Espectrometria de Massas em Tandem/métodos , Animais , Peixes , Hipnóticos e Sedativos/análise , Limite de Detecção , Aves Domésticas , Suínos
14.
Toxins (Basel) ; 2(4): 552-71, 2010 04.
Artigo em Inglês | MEDLINE | ID: mdl-22069599

RESUMO

The potent experimental renal carcinogenesis of ochratoxin A (OTA) in male rats makes the dietary contaminant a potential factor in human oncology. We explored whether the tumour promoter sodium barbitate could shorten the otherwise long latency between exposure to toxin and tumourigenesis. Young rats, of a hybrid in which mononuclear leukaemia was rare, were given feed contaminated (5 ppm) with OTA for 36 weeks to initiate renal tumourigenesis. Some individuals were thereafter given sodium barbitate (500 ppm in drinking water) for life. Pathological outcomes were studied at or near the end of natural life. Renal tumours in males given barbitate became evident after latency of one year, but only slightly before those without barbitate. In contrast, female mammary tumourigenesis was advanced by at least 6 months synchronously in all rats given the OTA-barbitate regimen compared to tumourigenesis in controls. Diagnosis of malignant mammary angiosarcoma in a female given the OTA-barbitate regimen is a new finding in the rat. The long latency of OTA-induced renal tumourigenesis was not notably susceptible to accelerated promotion by barbitate, contrasting with an apparently marked effect of barbitate on development of mammary tumours.


Assuntos
Barbital/toxicidade , Neoplasias Renais/induzido quimicamente , Neoplasias Mamárias Experimentais/induzido quimicamente , Micotoxinas/toxicidade , Ocratoxinas/toxicidade , Animais , Feminino , Masculino , Ocratoxinas/sangue , Projetos Piloto , Ratos , Ratos Endogâmicos F344 , Ratos Sprague-Dawley
15.
Hybridoma (Larchmt) ; 28(2): 145-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19382846

RESUMO

In this study, we prepared monoclonal antibodies against morphine, methadone, babital, methamphetamine, and phencyclidine, then developed a dot-ELISA method by such antibodies to test their efficacy in clinical application and the screening of urine samples. It was found that there were 36 narcotics-positive drug users, including 28 morphine positive, six methamphetamine positive, and two positive for both. All the results were confirmed by commercial drug testing kits.


Assuntos
Anticorpos Monoclonais/biossíntese , Barbital/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Metadona/imunologia , Metanfetamina/imunologia , Morfina/imunologia , Fenciclidina/imunologia , Detecção do Abuso de Substâncias/métodos , Anticorpos Monoclonais/urina , Humanos
16.
Cell Mol Biol (Noisy-le-grand) ; 55(1): 23-8, 2009 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-19267998

RESUMO

The N-methyl-diethyl-aspartate (NMDA) receptor has been reported to play an important role in several acute and chronic neuropathologic syndromes. 5-aminolevulinic acid (ALA) accumulates in acute porphyrias due to a deficiency in the heme biosynthetic pathway. Considering that glutamate uptake inhibition caused by ALA could be one of the reasons conducing to porphyric neuropathy, it was of interest to evaluate the effect of porphyrinogenic agents on NMDA glutamatergic system. To this end receptor levels and apparent affinity (Kd) were analyzed in mice brain cortex and cerebellum. NMDA levels were diminished after chronic Isoflurane anaesthesia in brain cortex. In cerebellum, a diminution was observed after acute Enflurane and Isoflurane and allylisopropylacetamide, while ethanol administration showed a significant increase. ALA administration diminished NMDA levels only in cerebellum. Affinity constant was only reduced in brain cortex after chronic Isoflurane treatment. In conclusion, glutamatergic system appears to be involved in the action of some of the porphyrinogenic drugs studied mainly in cerebellum. Receptors regulation should therefore be considered an important mechanism in the cellular response to specific drugs, with the aim of designing new therapies and elucidating the mechanisms leading to porphyric neuropathy and acute attack triggering.


Assuntos
Porfirinogênios/farmacologia , Ácido Aminolevulínico/farmacologia , Animais , Barbital/farmacologia , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Enflurano/farmacologia , Etanol/farmacologia , Griseofulvina/farmacologia , Isoflurano/farmacologia , Masculino , Camundongos , Receptores de N-Metil-D-Aspartato/metabolismo
17.
Immunopharmacol Immunotoxicol ; 30(3): 489-501, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18668394

RESUMO

Larrea divaricata is a plant widely used in folk medicine in Argentina. This work aimed to study the mechanisms of decoction activity on the release of oxygen reactive species. Decoction increased the binding of zymosan-FITC and superoxide production. Cadmium decreased the superoxide production as well as malonate and barbital. Decoction decreased the release of hydrogen peroxide. Decoction increased the reduction of MTT but not when malonate and barbital were included. Together, decoction increased the expression of dectin-1 leading to increased superoxide production. It is possible that decoction increases the activity of peroxidase, and decreases the Cu, Zn-superoxide dismutase.


Assuntos
Peróxido de Hidrogênio/metabolismo , Larrea , Macrófagos Peritoneais/efeitos dos fármacos , Extratos Vegetais/farmacologia , Receptores de Complemento/efeitos dos fármacos , Superóxidos/metabolismo , Animais , Barbital/farmacologia , Cloreto de Cádmio/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Larrea/química , Lectinas Tipo C , Macrófagos Peritoneais/metabolismo , Masculino , Malonatos/farmacologia , Proteínas de Membrana/metabolismo , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Componentes Aéreos da Planta , Receptores de Complemento/metabolismo , Zimosan/metabolismo
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(3): 648-51, 2008 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-18536434

RESUMO

The mechanism of interaction mechanism of barbital sodium with bovine serum albumin (BSA) was studied by fluorescence spectroscopy. According to the thermodynamics parameters, the main sort of binding force of the interaction is electrostatic force, and binding BBTS to BSA is a spontaneous supermolecular interaction in which entropy increases and Gibbs free energy decrease. The formation constants of them were analyzed according to Stern-Volmer equation and double-reciprocal equation, and are smaller at high temperature than at low temperature. It is confirmed that the combination reaction of BBTS with BSA is a static quenching process. The change in the micro-circumstance of amino of bovine serum albumin was analyzed by synchronous fluorescence spectrometry.


Assuntos
Barbital/química , Soroalbumina Bovina/análise , Termodinâmica , Animais , Bovinos , Estrutura Molecular , Soroalbumina Bovina/química , Espectrometria de Fluorescência
19.
Artigo em Inglês | MEDLINE | ID: mdl-17521958

RESUMO

Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes of barbital, thiouracil, adenine, amino acids (methionine, lysine and alanine) and some mixed ligands were prepared and characterized by elemental analyses, IR, electronic spectra, magnetic susceptibility and ESR spectra. Coordination of the metallic centre to the oxygen and nitrogen atoms of barbital, thiouracil, amino acids and coordinate to amino group and nitrogen atom of adenine occurred. Electronic spectra and magnetic susceptibility measurements were utilized to infer the structure of the complexes which are octahedral for Mn(II), Fe(III), Co(II), Ni(II) and Cd(II) and tetrahedral for Mn(II), Cu(II), Zn(II) complexes. ESR spectra were observed for copper complexes with a d(x2)-(y2) ground state with small g(||) values indicating strong interaction between the ligands and their metal ions.


Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Purinas/química , Purinas/síntese química , Pirimidinas/química , Pirimidinas/síntese química , Adenina/química , Barbital/química , Elétrons , Ligantes , Magnetismo , Metais/química , Espectrofotometria Infravermelho , Tiouracila/química
20.
Cell Mol Neurobiol ; 27(6): 717-29, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17676386

RESUMO

(1) We evaluated the involvement of brain mitochondrial and microsomal cytochrome P-450 in the metabolization of known porphyrinogenic agents, with the aim of improving the knowledge on the mechanism leading to porphyric neuropathy. We also compared the response in brain, liver and kidney. To this end, we determined mitochondrial and microsomal cytochrome P-450 levels and the activity of NADPH cytochrome P-450 reductase. (2) Animals were treated with known porphyrinogenic drugs such as volatile anaesthetics, allylisopropylacetamide, veronal, griseofulvin and ethanol or were starved during 24 h. Cytochrome P-450 levels and NADPH cytochrome P-450 reductase activity were measured in mitochondrial and microsomal fractions from the different tissues. (3) Some of the porphyrinogenic agents studied altered mitochondrial cytochrome P-450 brain but not microsomal cytochrome P-450. Oral griseofulvin induced an increase in mitochondrial cytochrome P-450 levels, while chronic Isoflurane produced a reduction on its levels, without alterations on microsomal cytochrome P-450. Allylisopropylacetamide diminished both mitochondrial and microsomal cytochrome P-450 brain levels; a similar pattern was detected in liver. Mitochondria cytochrome P-450 liver levels were only diminished after chronic Isoflurane administration. In kidney only mitochondrial cytochrome P-450 levels were modified by veronal; while in microsomes, only acute anaesthesia with Enflurane diminished cytochrome P-450 content. (4) Taking into account that delta-aminolevulinic acid would be responsible for porphyric neuropathy, we investigated the effect of acute and chronic delta-aminolevulinic acid administration. Acute delta-aminolevulinic acid administration reduced brain and liver cytochrome P-450 levels in both fractions; chronic delta-aminolevulinic acid administration diminished only liver mitochondrial cytochrome P-450. (5) Brain NADPH cytochrome P-450 reductase activity in animals receiving allylisopropylacetamide, dietary griseofulvin and delta-aminolevulinic acid showed a similar profile as that for total cytochrome P-450 levels. The same response was observed for the hepatic enzyme. (6) Results here reported revealed differential tissue responses against the xenobiotics assayed and give evidence on the participation of extrahepatic tissues in porphyrinogenic drug metabolization. These studies have demonstrated the presence of the integral Phase I drug metabolizing system in the brain, thus, total cytochrome P-450 and associated monooxygenases in brain microsomes and mitochondria would be taken into account when considering the xenobiotic metabolizing capability of this organ.


Assuntos
Encéfalo/metabolismo , Sistema Enzimático do Citocromo P-450/fisiologia , Microssomos/metabolismo , Mitocôndrias/metabolismo , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Porfiria Aguda Intermitente/induzido quimicamente , Alilisopropilacetamida/farmacocinética , Ácido Aminolevulínico/farmacologia , Animais , Barbital/farmacocinética , Encéfalo/efeitos dos fármacos , Etanol/farmacocinética , Griseofulvina/farmacocinética , Hipnóticos e Sedativos/farmacocinética , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Desentoxicação Metabólica Fase I/fisiologia , Camundongos , Fármacos Fotossensibilizantes/farmacocinética , Porfiria Aguda Intermitente/metabolismo
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