RESUMO
Sturge-Weber syndrome (SWS) is a capillary-venous malformation affecting the brain, the eye, and the adjacent trigeminal dermatomes of the skin. This illness is usually diagnosed during the first years of life. If left undiagnosed (and consequently untreated), the condition could develop into severe refractory seizures, ischemic strokes, visual loss, and early cognitive impairment. We report a case of a 23-year-old female patient with a port-wine facial stain, presenting her first convulsive episode in adulthood, associated with a moderate dilation of the deep venous system in the angiography, which raised the diagnostic of Sturge-Weber syndrome.
RESUMO
AIM: Cancer has emerged as a growing public health problem in many parts of the world. METHODOLOGY: We describe the synthesis of a series of carbohydrate-based isoquinoline-5,8-diones through the 1,4-addition reaction between 5,8-dioxo-5,8-dihydroisoquinoline and aminocarbohydrates. Halogenated quinones were also synthesized. Their inhibitory effects on the proliferation of human cancer cell lines were studied. RESULTS & CONCLUSION: The most promising compound, derived from isoquinoline-5,8-dione, containing ribofuranosidyl ring, was selectively active in vitro against H1299 cancer cells, with 1.7-fold higher activity than that of vinorelbine tartrate. This result suggests that the glycoconjugate in question may constitute a valuable lead compound to design and synthesize a more active and less toxic derivative with respect to the development of a new antitumor substance.
Assuntos
Antineoplásicos/farmacologia , Carboidratos/farmacologia , Isoquinolinas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Carboidratos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Isoquinolinas/química , Estrutura Molecular , Relação Estrutura-Atividade , Células VeroRESUMO
Chemical investigation of the CH2 Cl2 crude extract from the brown alga Canistrocarpus cervicornis (Dictyotaceae) led to isolation of one new (1) and four previously reported dolastane diterpenes (2-5). Their structures were characterized by 1D- and 2D-NMR spectroscopic techniques, including a full single crystal X-ray diffraction analysis for 1, 2, and 4. In addition, the new structure 1 was assayed as chemical defense inhibiting the feeding by the sea urchin Lytechinus variegatus. This study constitutes an additional report broadening the known spectrum of action and defensive roles of secondary metabolites of the C. cervicornis and Dictyotales species.
Assuntos
Diterpenos/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Lytechinus/efeitos dos fármacos , Phaeophyceae/química , Animais , Brasil , Diterpenos/química , Diterpenos/isolamento & purificação , Modelos Moleculares , Conformação MolecularRESUMO
In the present investigation, we studied the enzymatic synthesis of monoacylglycerols (MAG) and diacylglycerols (DAG) via the esterification of saturated fatty acids (stearic, palmitic and an industrial residue containing 87% palmitic acid) and glycerol in a solvent-free system. Three immobilized lipases (Lipozyme RM IM, Lipozyme TL IM and Novozym 435) and different reaction conditions were evaluated. Under the optimal reaction conditions, esterifications catalyzed by Lipozyme RM IM resulted in a mixture of MAG and DAG at high conversion rates for all of the substrates. In addition, except for the reaction of industrial residue at atmospheric pressure, all of these products met the World Health Organization and European Union directives for acylglycerol mixtures for use in food applications. The products were quantified by (13)C NMR, with the aid of an external reference signal which was generated from a sealed coaxial tube filled with acetonitrile-d3. After calibrating the area of this signal using the classical external reference method, the same coaxial tube was used repeatedly to quantify the reaction products.
Assuntos
Diglicerídeos/análise , Ácidos Graxos/química , Lipase/química , Espectroscopia de Ressonância Magnética/métodos , Monoglicerídeos/análise , Calibragem , Isótopos de Carbono , Catálise , Diglicerídeos/síntese química , Diglicerídeos/química , Esterificação , Monoglicerídeos/síntese química , Monoglicerídeos/química , Padrões de Referência , SolventesRESUMO
BACKGROUND: Nuclear magnetic resonance studies of banana fragments during ripening show an increase on the water transverse relaxation time (T2) and a decrease in water self-diffusion coefficient (D). As T(2) and D are normally directly correlated, we studied these two properties in intact bananas during ripening, in an attempt to rule out the effect of injury on the apparent discrepancies in the behavior of T(2) and D. RESULTS: The results show that injury in bananas causes a decrease in T2 of the water in vacuoles (T(2vac)). They also show that T(2vac) increased and D decreased during ripening, ruling out the injury effect. To explain the apparent discrepancies, we propose a new hypothesis for the increase in T2 values, based on the reduction of Fe3+ ions to Fe2+ by galacturonic acid, produced by the hydrolysis of pectin and a decrease in internal oxygen concentration during ripening. CONCLUSION: As injury alters T2 values it is necessary to use intact bananas to study relaxation times during ripening. The novel interpretation for the increase in T(2vac) based on reduction of Fe+3 and O2 concentration is an alternative mechanism to that based on the hydrolysis of starch in amyloplasts.
Assuntos
Cátions/metabolismo , Frutas/fisiologia , Ácidos Hexurônicos/metabolismo , Musa/fisiologia , Oxigênio/fisiologia , Pectinas/metabolismo , Água/fisiologia , Compostos Férricos/metabolismo , Compostos Ferrosos/metabolismo , Manipulação de Alimentos , Hidrólise , Espectroscopia de Ressonância Magnética/métodos , Vacúolos/fisiologiaRESUMO
Six new nor-beta-lapachones have been synthesized from reaction of 3-bromo-nor-beta-lapachone with arylamines. These derivatives have potent anticancer properties against several cell lines. Here, we report complete unambiguous assignments of (1)H and (13)C chemical shifts of the new compounds. The assignments were made using a combination of one- and two-dimensional NMR techniques ((1)H, (13)C, (1)H-(1)H COSY, (1)H-(13)C HSQC, and (1)H-(13)C HMBC).
Assuntos
Espectroscopia de Ressonância Magnética/métodos , Quinonas/química , Aminas/química , Antineoplásicos/química , Isótopos de Carbono , Furanos/química , Naftalenos/químicaRESUMO
Continuous wave free precession (CWFP) nuclear magnetic resonance is capable of yielding quantitative and easily obtainable information concerning the kinetics of processes that change the relaxation rates of the nuclear spins through the action of some external agent. In the present application, heat flow from a natural rubber sample to a liquid nitrogen thermal bath caused a large temperature gradient leading to a non-equilibrium temperature distribution. The ensuing local changes in the relaxation rates could be monitored by the decay of the CWFP signals and, from the decays, it was possible to ascertain the prevalence of a diffusive process and to obtain an average value for the thermal diffusivity.
RESUMO
The purpose of this communication is to describe a method for rapid and simultaneous determination of longitudinal (T1) and transversel (T2) relaxation times, based on a single continuous wave free precession (CWFP) experiment which employs RF pulses with a pi/2 flip angle. We analyze several examples, involving nuclei such as 1H, 31P, and 19F, where good agreement with T1 and T2 measurements obtained by traditional methods is apparent. We also compare with the more time-consuming steady-state free precession (SSFP) method of Kronenbitter and Schwenk where several experiments are needed to determine the optimum flip angle. The role of an inhomogeneous magnetic field on the observed decays and its effect upon the accuracy of relaxation times obtained by these methods is examined by comparing numerical simulations with experimental data. Possible sources of error and conditions to minimize its effects are described.