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M. Ramos Silva A. Matos Beja J. A. Paixo L. Alte da Veiga A. J. F. N. Sobral A. M. d'A. Rocha Gonsalves 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1263-1264
In the title compound, C16H17NO4, the benzyloxycarbonyl group is anti to the pyrrolic N atom. The molecules are joined into head‐to‐head dimers by hydrogen bonds involving the carboxylic acid groups. There is orientational disorder of these groups over two positions with approximately equal occupancy. A weaker hydrogen bond between the pyrrolic N atom and the carbonyl O atom of the benzyloxycarbonyl group joins the dimers into chains running parallel to the [110] direction. 相似文献
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CM Silva MF Duarte ML Mira MH Florêncio K Versluis AJ Heck 《Rapid communications in mass spectrometry : RCM》1999,13(12):1098-1103
Fast atom bombardment, combined with high-energy collision-induced tandem mass spectrometry, has been used to investigate gas-phase metal-ion interactions with captopril, enalaprilat and lisinopril, all angiotensin-converting enzyme inhibitors.Suggestions for the location of metal-binding sites are presented. For captopril, metal binding occurs most likely at both the sulphur and the nitrogen atom. For enalaprilat and lisinopril, binding preferably occurs at the amine nitrogen. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Pedro Silva Sofia M. Fonseca Cláudia T. Arranja Hugh D. Burrows Ana M. Urbano Abilio J. F. N. Sobral 《Photochemistry and photobiology》2010,86(5):1147-1153
A new 5,10,15,20-tetra-(phenoxy-3-carbonyl-1-amino-naphthyl)-porphyrin was prepared by an isocyanate condensation reaction and its photophysical properties fully evaluated, both in terms of photostability and singlet oxygen production. It shows considerably enhanced photostability when compared with the parent 5,10,15,20-tetra-(3-hydroxy-phenyl)-porphyrin, with the photodegradation quantum yields for T(NAF)PP and T(OH)PP being 4.65 × 10−4 and 5.19 × 10−3, respectively. Its photodynamic effect in human carcinoma HT-29 cells was evaluated. The new porphyrin showed good properties as a sensitizer in photodynamic therapy with an in vitro cytotoxicity IC50 value of 6.80 μg mL−1 for a 24 h incubation. In addition to the potential of this compound, the synthetic route used provides possibilities of extension to a wide range of new sensitizers. 相似文献
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M. A. da Silva P. J. A. Sobral T. G. Kieckbusch 《Journal of Thermal Analysis and Calorimetry》2006,84(2):435-439
Differential scanning calorimetry (DSC) was used
to determine phase transitions of freeze-dried camu-camu pulp in a wide range
of moisture content. Samples were equilibrated at 25°C over saturated
salt solutions in order to obtain water activities (aw)
between 0.11–0.90. Samples with aw>0.90
were obtained by direct water addition. At the low and intermediate moisture
content range, Gordon–Taylor model was able to predict the plasticizing
effect of water. In samples, with aw>0.90,
the glass transition curve exhibited a discontinuity and T’g was practically constant (–58.8°C), representing the glass transition
temperature of the maximally concentrated phase(Tg
). 相似文献
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Togashi DM Romão RI Gonçalves da Silva AM Sobral AJ Costa SM 《Physical chemistry chemical physics : PCCP》2005,7(22):3874-3883
Langmuir monolayers (LM) and Langmuir-Blodgett (LB) films of pure lipophilic meso-tetra(4-dodecylaminosulfophenyl)porphyrin (PC12) and mixed with the anionic surfactant sodium hexadecylsulfate (SHS) were studied. The molecular packing and structure of PC12 and PC12-4SHS with variable surface pressure were investigated by surface pressure-area measurements, steady-state absorption, fluorescence emission and anisotropy, as well as by fluorescence lifetime imaging microscopy (FLIM). At low surface pressure, the porphyrin molecules are organized with the rings tilted on the water surface whereas at high surface pressure the porphyrin rings achieve a more perpendicular arrangement. Using the FLIM images a gradual change of aggregates into large "islands" is observed. Different patterns are observed in the pure PC12 multilayer films (n = 3 and 5) with ordered patches superimposed which are not observed in the PC12-4SHS multilayer LB films. 相似文献
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Lúcio AS Almeida JR Barbosa-Filho JM Pita JC Branco MV Diniz Mde F Agra Mde F da-Cunha EV da Silva MS Tavares JF 《Molecules (Basel, Switzerland)》2011,16(8):7125-7131
Phytochemical investigation of Anaxagorea dolichocarpa Sprague & Sandwith led to isolation of three azaphenanthrene alkaloids: eupolauramine, sampangine and imbiline 1. Their chemical structures were established on the basis of spectroscopic data from IR, HR-ESI-MS, NMR (including 2D experiments) and comparison with the literature. Sampangine and imbiline 1 are being described in the Anaxagorea genus for the first time. Eupolauramine and sampangine show concentration-dependent antitumoral activity in leukemic cells K562 with IC(50) of 18.97 and 10.95 μg/mL, respectively. 相似文献
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