Licenciatura em Química (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/26
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APP - Artigo Publicado em Periódico
TAE - Trabalho Apresentado em Evento
TCC - Trabalho de Conclusão de Curso
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Resultados da Pesquisa
Item Atividade antimicrobiana de análogos da piperina(2018-08-02) Bezerra, Leonardo Alexandre Barros; Ramos, Clécio Souza; http://lattes.cnpq.br/3782004073843685; http://lattes.cnpq.br/3961756201958567The structural modification of natural compounds is of significant importance for medicinal chemistry, from 1981 to 2014 1328 medicines were approved for commercialization, of which 51.5% are of natural origin and 26.8% are derived from phytochemicals. An example is the natural amide piperine, which is the target of several biological investigations, and which has demonstrated the potential to act as a precursor to new compounds with application in the modulation of biological phenomena with the 1,2,4 oxadiazole nucleus, which are a class of heterocyclic that exhibit a range of biological activities and that can be used for the synthesis of potential microbial agents. This work aims to report the extraction of piperine by microwave. Reflux hydrolysis of piperine to obtain piperinic acid in moderate yields. Obtaining the ethyl piperininate esters and 3,4 methylenedioxy ethyl cinnamate with excellent yields. The synthesis of amidoximes using the conventional methodology of stirring with hydroxylamine hydrochloride, sodium carbonate and the corresponding nitriles with the substituents (p-nitro, p-toluyl, m-toluyl, benzo, piperonyl, 4-pyridine) in yields of 37% -98%. Using the methodology of synthesis of oxadiazole by microwave using ethyl cyano acetate esters with piperonylamidoxime, ethyl ester 3,4-methylenedioxy cinnamate with 4-pyridine and p-toluyl amidoxime in the presence of K2CO3 and DMF. All oxadiazol precursors were elucidated by IV and the 1,2,4-oxadiazoles synthesized characterized by 1H and 13C NMR. Some compounds were tested bactericidal activities, where the 1,2,4-oxadiazoles presented excellent results against Staphylococcus aureus and Klebsiella pneumoniae and one of the compounds presented luminescent activity a little reported in the 1,2,4 oxadiazoles.Item Síntese e caracterização de novos materiais luminescentes à base de glutamato e ítrio(2019-12-09) Valença, Maria Eduarda de Goes; Falcão, Eduardo Henrique Lago; Vila Nova, Suzana Pereira; http://lattes.cnpq.br/7716018904442218; http://lattes.cnpq.br/0614524019382645; http://lattes.cnpq.br/5887132704910210This work focuses on the synthesis of new luminescent materials using as precursors the commercial monosodium glutamate and rare earth ions (yttrium, neodymium and europium), which presented a gel aspect. The methodology used follows a previous work, in which a material containing glutamate and neodymium was obtained. The hypothesis raised was that it would be possible to obtain a similar material replacing the neodymium by the yttrium, based on the similar chemical properties between these two metals. This substitution is justified by the fact that neodymium is about three times more expensive than yttrium. Initially, materials containing only glutamate and yttrium were obtained, which presented a gel aspect, varying the proportions between the metal and the ligand. The proportion (in millimol) that contains the smallest amount of metal in relation to the binder and still forms the material with gel aspect is 1:10, metal-ligand, respectively. However, the proportion chosen to continue the work was 1:5, because it was also employed in the previous work. To the yttrium and glutamate gel were added varying amounts (1 to 50% mol) of neodymium and europium in order to assign luminescent properties to the material. The characterization of the materials included the techniques of infrared spectroscopy, Raman spectroscopy and luminescence spectroscopy. The infrared spectra of the material containing only yttrium and glutamate showed a profile similar to those of the material containing only neodymium and glutamate. The materials containing yttrium, neodymium and glutamate also followed the same profile, while those containing yttrium, europium and glutamate varied minimally. The Raman spectra of the yttrium and glutamate materials coincided with those of neodymium and glutamate. However, those of europium and glutamate materials varied substantially compared to the others. This suggests that the yttrium coordinates to the glutamate similarly to the neodymium does, but the europium coordinates differently. The luminescence spectra were obtained for the material containing only neodymium and for the material containing yttrium and neodymium. The characteristic Nd3+ transitions were observed, and the intensities varied according to the amount of neodymium present in each sample.Item Estudo sobre a influência das ligações [pi] na luminescência de novos complexos contendo íons lantanídeos(2019-07-17) Cavalcante, Caroliny Oliveira; Belian, Mônica Freire; http://lattes.cnpq.br/2626644337183959; http://lattes.cnpq.br/2665095680217539Researches about lanthanides ions have a growing interest in consequence of its photophysic properties, through several applications, among them; lasers, contrast agents, etc. These properties elapse from energy absorption of binder and emission in visible region because of metal type as example Eu3+ complexes which emit in red region. This process of energy transfer is called Antenna Effect. The carboxilate groups bond skillfully with these trivalent cations, for being Pearson’s hard bases and usually present high absorption and energy transfer. Some energy binder-metal transfer mechanisms are known, in which its study is necessary to creation of much more luminescence complexes, thus as spectroscopic studies and knowledge about binder’s triplet states, wherein such states are obtained from Gd3+ complexes’ phosphorescence. Because of that were synthetize complexes of trans-3(3-tienil)-acrylic acid and 4(2-tienil)-butyric acid with Eu3+ and Gd3+, mixing proportions; 3:1 and 4:1. The acids, carboxilates and all complexes were characterized by Infrared Spectroscopy, and done a spectroscopic study through Eletronic Luminescense Spectroscopy. In which were noticed the symmetric and asymmetric bands of group OCO-, besides maximum of excitation and emission of each Eu3+ complex. The emissions intensity on 5D0 -7F2 hypersensible transitions from ion were higher in Eu-ATA-3:1 and Eu-ATB-4:1, with diference between state T1 of binder and state D2 of ion near 440 cm-1 e 550 cm-1, respectively.