RESUMO
For the development of novel 5-HT(4) receptor ligands we have designed and synthesized two series of 5-methoxytryptamine derivatives varying the substitution on the primary amine. Their biological activities were evaluated in a receptor binding assay where a subset of compounds showed comparable potency to the agonists serotonin and 5-methoxytryptamine. Structure-activity analyses have highlighted promising avenues for further synthetic work and binding modes were proposed by docking these compounds into a homology model of the 5-HT(4) receptor.
Assuntos
Antagonistas do Receptor 5-HT4 de Serotonina/síntese química , Antagonistas do Receptor 5-HT4 de Serotonina/farmacologia , Triptaminas/farmacologia , 5-Metoxitriptamina/análogos & derivados , 5-Metoxitriptamina/síntese química , 5-Metoxitriptamina/metabolismo , 5-Metoxitriptamina/farmacologia , Animais , Células COS , Chlorocebus aethiops , Desenho de Fármacos , Descoberta de Drogas , Humanos , Ligantes , Receptores 5-HT4 de Serotonina/metabolismo , Receptores 5-HT4 de Serotonina/fisiologia , Triptaminas/agonistas , Triptaminas/síntese química , Triptaminas/químicaRESUMO
A series of 30 tripeptides were synthesized and tested as novel 5-HT4 receptor ligands. Receptor binding assays showed that a subset of compounds had reasonable potency relative to the agonists serotonin and 5-methoxytryptamine. Structure-activity analyses and molecular docking have highlighted avenues for further synthetic work.
Assuntos
Descoberta de Drogas , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Receptores 5-HT4 de Serotonina/metabolismo , Sequência de Aminoácidos , Aminas Biogênicas/metabolismo , Humanos , Ligantes , Modelos Moleculares , Receptores 5-HT4 de Serotonina/químicaAssuntos
Qualidade de Vida , Incontinência Urinária por Estresse/psicologia , Incontinência Urinária por Estresse/cirurgia , Procedimentos Cirúrgicos Urológicos/métodos , Vagina/cirurgia , Feminino , Humanos , Estudos Prospectivos , Disfunções Sexuais Fisiológicas/etiologia , Disfunções Sexuais Fisiológicas/terapia , Inquéritos e Questionários , Resultado do Tratamento , Incontinência Urinária por Estresse/complicações , Procedimentos Cirúrgicos Urológicos/instrumentaçãoRESUMO
Gynura procumbens is used in Thai folk medicine to treat topical inflammation, rheumatism, and viral ailments. In the present work, attempts were made to verify the folk medicinal claim that the crude ethanolic extract of G. procumbens has antiinflammatory action and to relate the activity to particular fractions using a croton oil-induced mouse ear inflammation model. The original ethanolic extract of G. procumbens was partitioned between water and ethyl acetate. The residues were subjected to antiinflammatory evaluation. While the water extract did not show any antiinflammatory activity, the administration of the original organic extract significantly inhibited the increase in ear thickness in response to croton oil (n = 5). The activity of 0.75 mg/ear original organic extract showed similar antiinflammatory activity (inhibition 65.2%) to that of 6 mg/ear hydrocortisone 21-hemisuccinate sodium salt (inhibition 64.8%). The organic extract was then fractionated with a series of solvents in order of increasing polarity. Each fraction was dried, dissolved in acetone and monitored using the same bioassay. These experiments showed that the hexane and toluene fractions showed significant inhibitions of 44.6% and 34.8%, respectively. These two fractions had similar activities to 4 mg/ear of hydrocortisone (inhibition 35.0%). The possible chemical constituents in the extracts and fractions were investigated using thin layer chromatography and specific color reagents. These tests showed that steroids might be one class of antiinflammatory compounds in this plant.
Assuntos
Anti-Inflamatórios/uso terapêutico , Asteraceae , Inflamação/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Plantas Medicinais , Animais , Anti-Inflamatórios/farmacologia , Asteraceae/química , Cromatografia em Camada Fina , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/análise , Plantas Medicinais/química , TailândiaRESUMO
Two cases of uterine perforation are described, occurring 11 days and 4 months, respectively, after the insertion of GyneFix, a frameless intra-uterine contraceptive device (IUD). In both the cases initial ultrasound scan showed the intra-uterine position of the device. Removal of the IUD, either by laparoscopy or laparotomy, had to be carried out. Awareness of this complication, insertion of GyneFix by a trained operator, appropriateness of ultrasound scan monitoring and possible underreporting of this complication are discussed.
Assuntos
Dispositivos Intrauterinos/efeitos adversos , Perfuração Uterina/etiologia , Adulto , Remoção de Dispositivo , Feminino , Migração de Corpo Estranho/diagnóstico por imagem , Humanos , Laparoscopia , Fatores de Tempo , Ultrassonografia , Perfuração Uterina/diagnóstico por imagem , Útero/diagnóstico por imagemRESUMO
Genuine stress incontinence is usually managed conservatively in women desirous of further childbearing. Tension-free vaginal taping is a relatively new method of surgical treatment of genuine stress incontinence. We report a case of pregnancy following the procedure. The patient was delivered by elective cesarean section. She remained continent throughout pregnancy and on a 6-month postnatal follow-up.
Assuntos
Gravidez , Incontinência Urinária por Estresse/cirurgia , Vagina/cirurgia , Adulto , Procedimentos Cirúrgicos Ambulatórios , Cesárea , Feminino , Humanos , Incontinência Urinária por Estresse/fisiopatologia , UrodinâmicaRESUMO
The ability of a series of sulphonylurea derivatives to antagonise the vasorelaxant actions of the ATP-dependent K+ channel (K(ATP)) opener, levcromakalim, and the vasoconstrictor responses of the thromboxane A2 mimetic, U46619, were assessed in the pig coronary artery. The sulphonylurea derivatives of glibenclamide caused a rightward shift in the concentration-vasorelaxant response curve obtained to levcromakalim in arterial segments pre-constricted with acetylcholine (0.5 microM). From these shifts pK(B) were calculated to estimate the potency of these compounds as levcromakalim antagonists. Similarly U46619 concentration-vasoconstrictor responses curves were constructed in the absence and in the presence of a sulphonylurea derivative and pK(B) values calculated. Regression analysis of pK(B) values showed that there was a significant correlation between the potency of these compounds in the two systems studied indicating similar structure-activity relationships apply in both cases. That sulphonylureas regulate K(ATP) channel opening is well known and they do so through a specific receptor associated with the channel. The results obtained in this study may indicate that a sulphonylurea receptor may also be associated with thromboxane A2 excitation-contraction coupling.
Assuntos
Benzopiranos/antagonistas & inibidores , Canais de Potássio/efeitos dos fármacos , Endoperóxidos Sintéticos de Prostaglandinas/farmacologia , Pirróis/antagonistas & inibidores , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacologia , Vasoconstritores/farmacologia , Vasodilatadores/antagonistas & inibidores , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Animais , Vasos Coronários/efeitos dos fármacos , Cromakalim , Glibureto/análogos & derivados , Glibureto/farmacologia , Oniocompostos/farmacologia , Compostos Organofosforados/farmacologia , Relação Estrutura-Atividade , SuínosRESUMO
Glibenclamide and analogs were tested for their ability to antagonize the vasorelaxant actions of the K+ channel opener levcromakalim in rat thoracic aorta, and to displace [3H]-glibenclamide binding from rat cerebral cortex membranes. Aortic ring segments were suspended in organ baths to record isometric tension. Tissues were precontracted with K+ (20 mM), and full concentration-relaxation curves were constructed to levcromakalim (0.01-30 microM) in the absence and presence of glibenclamide or analog. The majority of the amidoethylbenzenesulfonylurea based compounds (exemplified by glibenclamide) caused parallel rightward shifts in the levcromakalim concentration-effect curves without effecting the maximum response to levcromakalim. Sulfonamide based compounds were generally inactive, with the exception of the compound DK#1 (laboratory code), which was unusually active as an antagonist of levcromakalim-mediated responses. The compounds were 1,000 to 10,000 times more potent at displacing [3H]-glibenclamide binding from rat cerebral cortex membranes. There was a strong correlation between the activity of amidoethylbenzenesulfonylurea based compounds as antagonists of the effects of levcromakalim and their ability to displace [3H]-glibenclamide binding. The slope of the regression line indicated that structural modification to these compounds has a more dramatic effect on their actions as levcromakalim antagonists than on their ability to displace [3H]-glibenclamide binding. This relationship of activity for the amidoethylbenzenesulfonylureas did not hold in the case of the sulfonamide derivatives. The results show that, for the processes characterized in this study (vascular levcromakalim antagonism vs. sulfonylurea receptor affinity), there are quantitative differences in their sensitivities to sulfonamide/sulfonylurea based compounds. Such differentiation may be important in the development of tissue-specific compounds.
Assuntos
Aorta/efeitos dos fármacos , Benzopiranos/antagonistas & inibidores , Córtex Cerebral/efeitos dos fármacos , Glibureto/análogos & derivados , Pirróis/antagonistas & inibidores , Vasodilatadores/antagonistas & inibidores , Animais , Aorta/metabolismo , Sítios de Ligação , Membrana Celular/metabolismo , Córtex Cerebral/metabolismo , Cromakalim , Glibureto/metabolismo , Glibureto/farmacologia , Técnicas In Vitro , Masculino , Canais de Potássio/efeitos dos fármacos , Ratos , Ratos Endogâmicos WKY , Relação Estrutura-AtividadeRESUMO
The synthesis of a series of mono- and disubstituted N-phenylanthranilic acids is described. Substituents on the phenyl ring include Cl, CN, OH, CF3, Br, I, CH3, OCH3, and OCF2CF2H. These compounds have been tested for their inhibitory effect on triiodothyronine (T3) uptake by H4 hepatocytes. The nonsteroidal antiinflammatory drugs flufenamic acid, mefenamic acid, and meclofenamic acid and the structurally related compounds 2,3-dimethyldiphenylamine and diclofenac were also tested. The most potent compounds were found to be, in order of decreasing activity, meclofenamic acid (2,6-Cl2,3-CH3), flufenamic acid (3-CF3), mefenamic acid (2,3-(CH3)2), and the compounds with 3,5-Cl2 and 3-OCF2CF2H substituents. The least potent compounds had 3-CN and 3-OH substituents. An analysis of quantitative structure-activity relationships (QSAR) for the series of phenylanthranilic acids showed that the inhibition of T3 uptake is highly dependent on the hydrophobicity of the compound. The relationship between uptake inhibition and the calculated octanol-water partition coefficient (clogP) was found to be parabolic, with optimum inhibitory activity found when the clogP of the phenylanthranilic acid was 5.7. It was also found that the 1-carboxylic acid group of the phenylanthranilic acids was not a prerequisite for uptake inhibition to occur, but its removal or alteration resulted in reduced inhibition.
Assuntos
Fígado/metabolismo , Tri-Iodotironina/metabolismo , ortoaminobenzoatos/química , Animais , Fenômenos Químicos , Físico-Química , Ácido Flufenâmico/farmacologia , Fígado/efeitos dos fármacos , Neoplasias Hepáticas Experimentais , Ácido Meclofenâmico/farmacologia , Ácido Mefenâmico/farmacologia , Estrutura Molecular , Ratos , Relação Estrutura-Atividade , Células Tumorais Cultivadas , ortoaminobenzoatos/farmacologiaRESUMO
A series of 3,4-dihydro-1,3-benzoxazine and 3,4-dihydro-1,3-pyridooxazine derivatives was synthesized, and the hydrolysis of the derivatives was studied with proton nuclear magnetic resonance spectroscopy. The oxazine derivatives underwent various degrees of hydrolysis when H2O was added to dimethyl sulfoxide solutions of the compounds. The rates and extents of decomposition of the oxazine ring systems depended on the electronic effects of substituents within the molecules. Examination of the proton nuclear magnetic resonance spectra that were generated during decomposition of the oxazines and trends in stability of the oxazine derivatives suggest the formation of an intermediate in the hydrolysis mechanism.
Assuntos
Oxazinas/análise , Estabilidade de Medicamentos , Hidrólise , Técnicas In Vitro , Espectroscopia de Ressonância MagnéticaRESUMO
The antiarrhythmic drug amiodarone has recently been characterized as the first known thyroid hormone antagonist. Its mode of interaction with the thyroid hormone receptor is therefore of interest. A computational analysis of the conformational flexibility of amiodarone using molecular mechanics and the semiempirical molecular orbital method AM1 has been performed. The molecular mechanics studies show that the low-energy conformations of the benzoylbenzofuran portion of amiodarone can be grouped into 4 distinct classes, while the diethylaminoethoxy side chain is extremely flexible. Conformers representative of the 4 low-energy classes were fitted to an extended thyroid hormone receptor model. Four independent modes in which amiodarone could bind to the thyroid hormone receptor site were evaluated.
Assuntos
Amiodarona/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Amiodarona/química , Sítios de Ligação , Modelos Moleculares , Conformação Molecular , Receptores dos Hormônios Tireóideos/química , TermodinâmicaRESUMO
An investigation of the crystal structure of cytosolic pig-heart aspartate aminotransferase (AAT, E.C.2.6.1.1) was carried out to determine the structural requirements for ligand recognition by the active site. Structural differences were observed between the two active sites of the AAT dimer. The natural ligand, L-aspartate, was docked into both active sites using various methods. However, due to structural differences, the ligand was able to form all the necessary interactions for initial binding in only one of the active sites. The program GRID (P.J. Goodford, J. Med. Chem. 1985, 28, 849-857) was used to predict favorable binding sites for the functional groups of the aspartate ligand. These binding sites corresponded to the position of the docked aspartate ligand, indicating that substrate recognition takes place before any major conformational changes occur within the enzyme.
Assuntos
Aspartato Aminotransferases/química , Gráficos por Computador , Miocárdio/enzimologia , Animais , Aspartato Aminotransferases/metabolismo , Ácido Aspártico/metabolismo , Sítios de Ligação , Galinhas , Citosol/enzimologia , Conformação Proteica , SuínosRESUMO
1. A series of compounds has been prepared which are analogues of the transition state of the reaction catalysed by L-dopa decarboxylase (EC 4.1.1.28). 2. These compounds are reduced adducts of the substrate (L-dopa) and coenzyme (pyridoxal phosphate), as well as analogues of these substances (D-dopa, pyridoxal and salicaldehyde). 3. Compounds were also prepared with an oxazine link between the 3'-oxygen and the nitrogen attached to the 4'-carbon of the aldehyde moiety. 4. None of the D-dopa adducts produced any significant inhibition, but the L-dopa adducts were all active at millimolar levels, with the oxazine derivatives being more active than their parent compounds. 5. Inhibition was competitive with respect to L-dopa, but was neither competitive nor non-competitive with respect to pyridoxal phosphate. 6. The most active compound tested was the oxazine derivative of the L-dopa/salicaldehyde adduct, with an estimated Ki of 58.0 microM. 7. Increased inhibitory activity was observed when enzyme depleted of pyridoxal phosphate was used.
Assuntos
Inibidores das Descarboxilases de Aminoácidos Aromáticos , Inibidores Enzimáticos/classificação , Levodopa/análogos & derivados , Animais , Sítios de Ligação , Ligação Competitiva , Catálise , Rim/enzimologia , Modelos Teóricos , Fosfato de Piridoxal/isolamento & purificação , Fosfato de Piridoxal/fisiologia , SuínosRESUMO
In a study comparing intravenous prostaglandin E2 (PGE2) with extra-amniotic PGE2 for the induction of labour, in patients with unfavourable induction features, we found no difference between the two methods in either safety or efficacy. However, we would not recommend the use of the extra-amninotic route as a routine method because of some technical difficulties.