Structural elucidation

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Spectroscopy study on structural elucidation of flavonoids from Solanum jabrense Agra & Nee e S. paludosum Moric.

Spectroscopy study on structural elucidation of flavonoids from Solanum jabrense Agra & Nee e S. paludosum Moric.

A distinção entre flavonas (H-3) e flavonois (RO-3) foi verifi- cada pela ausência do sinal de carbono metínico em torno de δ C 103 (CH-3 de flavonas) e a presença do sinal de C-3 em to[r]

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New Triterpenes from Maytenus robusta: Structural Elucidation Based on NMR Experimental Data and Theoretical Calculations

New Triterpenes from Maytenus robusta: Structural Elucidation Based on NMR Experimental Data and Theoretical Calculations

The 13 C-NMR data of the group of low-intensity signals (named triterpene 10 ) present a signal at C 180.1 which is characteristic of a carboxylic carbon.. The signals at C 148.7 an[r]

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A New Benzophenone from Garcinia benthamiana

A New Benzophenone from Garcinia benthamiana

Abstract: A detailed phytochemical study on the stem bark of Garcinia benthamiana has afforded a new benzophenone, benthamianone (1), together with congestiflorone (2), a mixture of stigmasterol (3) and γ- sitosterol (4) as well as a mixture of phloroglucinol (5) and methyl palmitate (6). The structural elucidation of these compounds was performed through analysis of their spectroscopic data (NMR spectra and MS). This is the first report on the phytochemistry of Garcinia benthamiana.

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J. Braz. Chem. Soc.  vol.27 número8

J. Braz. Chem. Soc. vol.27 número8

told, we had 8 plenary lectures, 14 invited lectures, 12 short lectures, and 284 posters. One last effort was demanded, though, a special natural products issue in our Journal of the Brazilian Chemical Society, paying tribute to our biodiversity. This indeed was achieved thanks to the contributions of many renowned international scientists and speakers, from Brazil and all over the world. This special issue covers all aspects of the research on natural products such as isolation, structural, elucidation, bioactivities displayed in 6 reviews and 15 articles, focusing the chemistry and biosynthesis of plants, microorganisms and others. We are certainly grateful to all contributors and we hope this issue will remain special for many generations.
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REPOSITORIO INSTITUCIONAL DA UFOP: Stereochemistry of 16α-hydroxyfriedelin and 3-oxo-16-methylfriedel-16-ene established by 2D NMR spectroscopy.

REPOSITORIO INSTITUCIONAL DA UFOP: Stereochemistry of 16α-hydroxyfriedelin and 3-oxo-16-methylfriedel-16-ene established by 2D NMR spectroscopy.

The identification of 1, 2, 3, 5 and 6 was initially developed through TLC using patterns of PCTT compounds which are commonly isolated from species of the Celastraceae family, and followed by the comparison of the NMR spectral features with literature data [5, 17]. The structural elucidation, including the stereochemistry of compounds 4 and 7, was based on the chemical shifts assignments obtained from 1D ( 1 H, 13 C and DEPT-135) and 2D (HMQC, HMBC, COSY and NOESY) NMR spectral data and mass spectrometry (GC-MS).

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6 Determination of Antioxidant Compounds in Foodstuff

6 Determination of Antioxidant Compounds in Foodstuff

Near infrared spectrometry (NIRS) is another sensitive technology to help in the structural elucidation of antioxidants. This technique has been Th described as fast, noninvasive, low cost, non-polluting and nondestructive in the analysis of food matrices [90, 225]. It is a spectroscopic method that uses the near-infrared region of the electromagnetic spectrum within the wavelength range of about 700 nm to 2500 nm. Near-infrared spectros- copy is a technique extensively used in agriculture for the determination of the quality of grain, fruits, vegetables, meat, among other agricultural products. Several studies are described in the literature reporting the use of NIRS for the determination of natural antioxidants: total carotenoids [226]; individual carotenoids such as lycopene and lutein [227,  228]; β-carotene [228]; malvidin-3-glucoside and tannins [229]; and polysac- charides [230]. In other studies, Pissard et al. [231] and Blanco-Díaz et al. [232] also determined ascorbic acid using NIRS. Polypeptides, fatty acids, esters and acids were also determined in cheese by this technology [233]; and fucoidan from Malaysian seaweeds [234].
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Aplicação da análise de séries temporais para detecção e prognóstico de danos em estruturas inteligentes

Aplicação da análise de séries temporais para detecção e prognóstico de danos em estruturas inteligentes

As it can be noticed, the creation of predictive models is the main key for damage prognosis. After the current damage level is characterized by a SHM technique, it is evaluated in terms of failure mechanics and a damage law (KULKARNI; ACHENBACH, 2008). Since crack propagation is mainly caused by fatigue, different methods have been used to characterize and predict loading (LING; MAHADEVAN, 2012). A different approach is to attempt to model the structure’s response under different levels of damage. This was performed by Albakri and Tarazaga (2014) who created electromechanical impedance signatures based on spectral element method. The prediction behavior of the model was verified by subsequent reductions in the stiffness of the modeled structure beside changes in the damage width and location. Another approach is to use statistical models to track changes in the structural condition.
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PROPEC-Programa de Pós Graduação em Engenharia Cívil :: APPROACHES FOR AUTOMATED DAMAGE DETECTION IN STRUCTURAL HEALTH MONITORING

PROPEC-Programa de Pós Graduação em Engenharia Cívil :: APPROACHES FOR AUTOMATED DAMAGE DETECTION IN STRUCTURAL HEALTH MONITORING

Over the last decades, several techniques have been developed in the context of Structural Health Monitoring (SHM) programs. However, when it comes to novelty (or damage) detection, these methods are inevitably based on human decisions. Moreover, most of the strategies already published in this topic mainly focus on modal identification procedures and tracking their outputs i.e., structural modal parameters. Such approaches usually lead to high computational costs and can still be insensitive to minor changes in structural behavior, thus missing crucial damage scenarios in their initial manifestations. To circumvent these drawbacks, recent researches showed that the use of symbolic representations derived directly from raw time-domain data (e.g. acceleration measurements) could provide more damage- sensitive responses with lower computational effort. Indeed, good results have been achieved by representing raw measurements in terms of their statistical distributions over time. Nevertheless, the lack of information regarding the frequency spectrum represents a decisive drawback. Therefore, this paper presents a novel symbolic object, which considers both time and frequency responses of structural dynamic measurements. Then, the proposed methodology employs a k-medoids clustering over such objects within a moving time- window framework and uses a single-valued index to indicate whether a novelty is present in the acquired data. Two practical studies – a 3D frame tested in laboratory and a motorway bridge – show that the proposed approach provide an unsupervised and adaptive scheme for SHM applications.
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Rev. Bras. Hematol. Hemoter.  vol.29 número2

Rev. Bras. Hematol. Hemoter. vol.29 número2

what main hematological changes in aging are independently associated to diseases and physiological dysfunction? To contribute to the elucidation of this question, the present study was performed with four general objectives: (1) to identify the prevalence of apparently healthy elderly subjects (HE); (2) to compare the hematological parameters between AHE and a young adult group (YA); (3) to compare nutritional indicators between AHE and elderly people who have some dysfunction or morbidity (HD) and to compare nutritional indicators between anemic and non-anemic HE.

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Efeitos do ambiente enriquecido nos níveis centrais e periférico de BDNF e sua relação com o desempenho na tarefa de reconhecimento de objetos em ratos

Efeitos do ambiente enriquecido nos níveis centrais e periférico de BDNF e sua relação com o desempenho na tarefa de reconhecimento de objetos em ratos

Studies with animal models showed that cellular, structural and behavioral changes induced by environmental enrichment are related to increased levels of BDNF in the brain. These evidences suggest that BDNF could be an interesting biomarker of the effects of lifestyle on cognition and other behavioral parameters in humans. To test this hypothesis, we analyzed the effects of environmental enrichment on long term memory for object recognition and on BDNF levels of hippocampus, frontal cortex and serum of rats exposed to an experimental protocol that could be more easily translated to human intervention studies. Animals were maintained for 10 weeks in a social (standard laboratory conditions) or enriched (increased opportunity for physical exercise a learning experiences) condition. In the 7 th week they were submitted to behavioral testing (open field and novel object memory task) and at the end of the 10 th week they were killed and BDNF levels were analyzed. Animals maintained in the enriched condition showed enhanced performance on the memory task in the absence of any significant alteration in central or peripheral BDNF levels. The results of this study are important to highlight the need to develop experimental protocols using animal models that more closely resemble the characteristics of studies with humans and motivate more investigations to determine the conditions under which BDNF could be a biomarker of the effects of environment enrichment.
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Immunological assays employed for the elucidation of an histoplasmosis outbreak in São Paulo, SP

Immunological assays employed for the elucidation of an histoplasmosis outbreak in São Paulo, SP

In summary, this report demonstrated as well as pro- ven the potential usefulness of two different serological as- says as complementary for elucidation of cases, especially when the mycological tests were not requested and or avail- able. The IB assay showed more sensitivity, in turn, the DI is more suitable to monitor disease prognosis. Furthermore the use of a more sensitive method such as IB has allowed us to provide the Vigilância Epidemiológica de Areias a rapid and reliable response allowing appropriate action to be taken.

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High Resolution Mass Spectrometry Elucidation of Captopril’s Ozonation and Chlorination By-Products

High Resolution Mass Spectrometry Elucidation of Captopril’s Ozonation and Chlorination By-Products

The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focus- ing on the identification, mass spectrometry and elucidation of its by-pro- ducts by applying direct infusion and high performance liquid chromatogra- phy, electrospray ionization high resolution mass spectrometry, in the nega- tive ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorina- tion, there was complete oxidation of captopril, i . e ., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the forma- tion of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay.
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Isolation and Structure Elucidation of a New Triterpenoid from Prunus cerasoides D. Don

Isolation and Structure Elucidation of a New Triterpenoid from Prunus cerasoides D. Don

Prunus is a genus of trees and shrubs, including the plums, cherries, peaches, apricots, and almonds. It is traditionally placed within the rose family, rosaceae [1]. The plant Prunus cerasoides D. Don is found in East Asia and commonly known as the Wild Himalayan Cherry. Its range extends in the Himalayas from Himachal Pradesh in India to southwest China and Burma. It grows in the forest from 1200 to 2400 meters above sea level [2–3]. The fruits and the leaves give a dark green dye. Seeds can be used in the manufacture of necklaces and rosaries. The wood is hard, strong, durable and aromatic, and branches are used as walking sticks. The branches and stems of the plant are also used for the treatment of gravel, kidney stones, asthma, thirst, leucoderma, liprosy, vomiting, and as antipyretic and refrigerant [4–5]. Because of their considerable value as both food and ornamental plants, many Prunus species have been introduced to the various parts of the World. All the members of the genus contain amygdalin and prunasin, which break down in water to form hydrocyanic acid (cyanide or prussic acid). In small amounts this exceedingly poisonous compound has been shown to stimulate respiration, and improve digestion. In excess, however, it can cause respiratory failure and even death [1]. Previously, some flavonoids and steroidal derivatives have been reported from P. cerasoides [2–3]. In the present paper, we report the isolation and structure elucidation of a new derivative of pentacyclic triterpenoids, named prunol (1).
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UNIVERSIDADE FEDERAL DE UBERLÂNDIA FACULDADE DE ENGENHARIA AERONÁUTICA VICTOR HUGO ALVES BORGES

UNIVERSIDADE FEDERAL DE UBERLÂNDIA FACULDADE DE ENGENHARIA AERONÁUTICA VICTOR HUGO ALVES BORGES

Os métodos de monitoramento de integridade estrutural (Structural Health Monitoring - SHM) são utilizados para inspecionar e detectar danos em estruturas.. E um dos métodos que está mostrando resultados promissores é o de monitoramento de integridade estrutural baseado em Impedância eletromecânica (Impedance-based Structural Health Monitoring - ISHM). Esta ferramenta destaca- se como uma técnica versátil, que pode ser facilmente aplicada em estruturas complexas devido à portabilidade dos instrumentos, facilidade e agilidade no processamento de dados, gerando informações em tempo real sobre a estrutura. Este método baseia-se no princípio da impedância eletromecânica (EMI), que utiliza a interação entre as propriedades mecânicas e elétricas de um transdutor piezoelétrico acoplado ou incorporado em uma estrutura para medir as assinaturas de impedância. Com essas assinaturas, é possível avaliar qualitativamente a presença do dano. E para quantificar as mudanças nas assinaturas de impedância, são utilizadas funções matemáticas chamada métricas de danos. Apesar das vantagens do método de impedância, esta técnica ainda apresenta algumas desvantagens, como influência nas medições da variação de temperatura, de cargas estáticas e dinâmicas, provocando falsos positivos na detecção de dano. Com isso, este artigo se concentra na aplicação do método SHM baseado em Impedância, realizando dois experimentos em estruturas sob vibrações externas, cargas estáticas e variações de temperatura para analisar sua influência nas assinaturas de impedância. Para isso, foi feito uma viga de alumínio com um transdutor piezoelétrico. Além disso, para avaliar a detecção de danos da técnica sob várias condições de contorno, foi simulado um dano na estrutura , no caso, foi removido a porca e o parafuso da viga.
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Elucidation of the binding mechanism of coumarin derivatives with human serum albumin.

Elucidation of the binding mechanism of coumarin derivatives with human serum albumin.

parallel) and 17.8% random coil which is in close agreement with our previous reports [30–34]. From our results, it was found that upon complexation of HSA with different coumarin derivatives (0.001, 0.003 and 0.005 mM), the a-helical content decreased from 57 to 47, 53 and 43% with a increase in b-sheets from 25 to 31, 29 and 33% and random coils from 18 to 22, 19 and 24% for CD enamide, CD enoate and CDM enamide, respectively (Table S2, Figure 5).The proportion of secondary structural elements undergoes marginal variation at low concentrations of coumarin derivatives (Figure 5). However, at the higher concentrations of coumarin derivatives, there was a noticeable change in the secondary structure of protein. These results suggest that the secondary structure of HSA became partially unfolded due to HSA-coumarin derivatives complexes formation. Secondary structural conformational changes occur as interior flexibility of the IB–IIA domain of HSA due to binding of different coumarin derivatives which have been shown from docking studies. Recently, our group reported that N-trans-p-coumaroyltyramine, a natural compound bound to HSA, leads to conformational changes due to inherent flexibility at the IIA domain [33]. Similar results were observed upon binding of other ligands (pentacyclic triterpenoids derivatives of betulinic acid and feruloyl maslinic acid, trimethoxy flavone, coumaroyltyramine and b-sitosterol) to HSA, thus indicating a major decrease of a- helices and an increase of b-sheets as well as random coils [30–34].
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Arq. NeuroPsiquiatr.  vol.68 número6

Arq. NeuroPsiquiatr. vol.68 número6

Results: hirty nurses answered the questionnaire. All participants came to the conclusion that newborn feels pain; both behavioral and physiological parameters were used to evaluate it. he irst and second evaluations using the NIPS, however without elucidation of parame- ters revealed 18 (30%) newborns diagnosed with pain and 42 (70%) diagnosed with no pain. he third and fourth evaluations, after elucidation about NIPS revealed an in- creased number of infants diagnosed with pain (n=39, 65%) and a decreased number of newborns diagnosed with no pain (n=21, 35%).

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Transcriptional repression of E-cadherin by human papillomavirus type 16 E6.

Transcriptional repression of E-cadherin by human papillomavirus type 16 E6.

Key observations in elucidation of the mechanism of E6 regulation of E-cadherin transcription are that DNMT activity is increased in E6 expressing cells and that exposure to an inhibitor[r]

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Viral diseases and human evolution

Viral diseases and human evolution

Although we have good examples of viruses that reflect human history, the possible elucidation of the origin of most group of viruses, based on the biogeographical distribution of its ge[r]

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Integrating Protein Structural Information

Integrating Protein Structural Information

Molecular biology changed in 1953 with the publication of a structural model of DNA by Watson and Crick (Watson and Crick 1953). Aside from its importance in this field, this model illustrates the combination of theoretical considerations and empirical data that is necessary for modelling macromolecular structures. Watson and Crick were aware of the X-Ray diffraction patterns of DNA crystals that indicated DNA formed a helical structure, and of the near-unitary ratios of adenine to thymine and guanine to cytosine always found in DNA. These data had direct implications for DNA structure. In addition, there were theoretical considerations on atomic radii, bond angles and distances, hydrogen bonding and, especially, the ability of DNA to be copied in living organisms. In short, the relevant information was diverse and broadly divided into two categories: observation data on the structure to model and other information on its purpose, similar molecules, and general chemistry.
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art fnafreire structural properties

art fnafreire structural properties

In this paper the structural characteristics of the B-site modified calcium titanate ceramics was discussed. The compounds were prepared by the conventional solid-state method and they were studied using XRD, IR, Raman scattering spectroscopy and micro- wave properties. The samples belongs to the Pbmn spatial group. A refinement analysis was performed and discussed. A quantitative phase analysis (QPA) of the samples, originated from the refinement procedure, was obtained and we can observe a good agreement with a previously published single-crystal study.

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