Chemical characterization of Sambucus nigra L. flowers aqueous extract and its biological implications

The main goal of this study was to chemically characterize an aqueous S. nigra flower extract and validate it as a bioactive agent. The elderflower aqueous extraction was performed at different temperatures (50, 70 and 90 °C). The extract obtained at 90 °C exhibited the highest phenolic content and antiradical activity. Therefore, this extract was analyzed by GC-MS and HPLC-MS, which allowed the identification of 46 compounds, being quercetin and chlorogenic acid derivatives representative of 86% of the total of phenolic compounds identified in hydrophilic fraction of the aqueous extract. Naringenin (27.2%) was the major compound present in the lipophilic fraction. The antiproliferative effects of the S. nigra extract were evaluated using the colon cancer cell lines RKO, HCT-116, Caco-2 and the extracts antigenotoxic potential was evaluated by the Comet assay in RKO cells. The RKO cells were the most susceptible to S. nigra flower extract (IC50=1250 µg mL1). Moreover, the extract showed antimicrobial activity against Gram-positive bacteria, particularly Staphylococcus aureus and S. epidermidis. These results show that S. nigra-based extracts can be an important dietary source of bioactive phenolic compounds that contribute to health-span improving life quality, demonstrating their potential as nutraceutical, functional foods and/or cosmetic components for therapeutic purposes.This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and for Scientific Employment Stimulus 2017 (CEECIND/01507/2017) provided to Ana M. Sousa.info:eu-repo/semantics/publishedVersio

Microwave-Assisted Extraction of Polyphenols from Eucalyptus Bark—A First Step for a Green Production of Tannin-Based Coagulants

Tannins are natural polyphenolic compounds widely found in plants. The production of natural coagulants for water treatment is one of their new applications. Polyphenols extraction is the first step for synthesizing tannin-based coagulants. Eucalyptus globulus bark (EGB), an abundant by-product of the pulp and paper industry, usually applied as fuel for energy production, was used in this work as a tannin source. The extraction of polyphenols from EGB was studied using water as a solvent. Extraction assays employing different extraction techniques were conducted. Microwave-assisted extraction showed superior performance and was further optimized. The influence of irradiation time, water-to-bark ratio, and temperature were evaluated using Response Surface Methodology. The extraction yield and the total phenolic content of the extract were modeled as function of the extraction conditions. The overall best conditions that maximize both responses were obtained through multi-response optimization. Optimized values (15% of extraction yield and a phenolic content of 354 mg of gallic acid equivalents per gram of extract) were predicted for an extraction time of 15 s, a liquid-to-solid ratio of 48.5 mL/g, and 141 °C. The extract generated under these conditions presented a condensed tannin content of 645 mg/g, expressed in terms of catechin equivalents. EGB presented good tannin-extractable contents to produce natural coagulants

Epidemiological aspects of hepatitis C virus infection among renal transplant recipients in central Brazil

Submitted by Franciele Moreira ([email protected]) on 2019-09-26T13:36:51Z No. of bitstreams: 2 Artigo - Silvia Marçal Botelho - 2008.pdf: 322136 bytes, checksum: 234f7f6db171ccf5d8b4d7fd42a39a6f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2019-09-26T13:41:26Z (GMT) No. of bitstreams: 2 Artigo - Silvia Marçal Botelho - 2008.pdf: 322136 bytes, checksum: 234f7f6db171ccf5d8b4d7fd42a39a6f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2019-09-26T13:41:26Z (GMT). No. of bitstreams: 2 Artigo - Silvia Marçal Botelho - 2008.pdf: 322136 bytes, checksum: 234f7f6db171ccf5d8b4d7fd42a39a6f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2008-08An investigation was conducted involving 255 renal transplant recipients in the state of Goiás, Central Brazil, to determine the prevalence of hepatitis C virus (HCV), its risk factors, the genotypes involved, and the level of alanine aminotransferase (ALT) present in the patients. All serum samples were tested for anti-HCV antibodies and HCV RNA. Forty-one patients were anti-HCV and/or HCV RNA positive, resulting in an overall HCV infection prevalence of 16.1% (95% CI: 11.9-21.3). A multivariate analysis of risk factors showed that a history of blood transfusions without anti-HCV screening, the length of time spent on hemodialysis, and renal transplantation before 1994 are all associated with HCV positivity. In HCV-positive patients, only 12.2% had ALT levels above normal. Twenty-eight samples were genotyped as genotype 1, subtypes 1a (62.5%) and 1b (31.3%), and two samples (6.2%) were genotype 3, subtype 3a. These data show a high prevalence of HCV infection and low ALT levels in the studied population. The risk factor analysis findings emphasize the importance of public health strategies such as anti-HCV screening of candidate blood and organ donors, in addition to the stricter adoption of hemodialysis-specific infection control measures. The present study also demonstrates that HCV genotype 1 (subtype 1a) is predominant in this populatio

Epidemiological aspects of hepatitis C virus infection among renal transplant recipients in Central Brazil

An investigation was conducted involving 255 renal transplant recipients in the state of Goiás, Central Brazil, to determine the prevalence of hepatitis C virus (HCV), its risk factors, the genotypes involved, and the level of alanine aminotransferase (ALT) present in the patients. All serum samples were tested for anti-HCV antibodies and HCV RNA. Forty-one patients were anti-HCV and/or HCV RNA positive, resulting in an overall HCV infection prevalence of 16.1% (95% CI: 11.9-21.3). A multivariate analysis of risk factors showed that a history of blood transfusions without anti-HCV screening, the length of time spent on hemodialysis, and renal transplantation before 1994 are all associated with HCV positivity. In HCV-positive patients, only 12.2% had ALT levels above normal. Twenty-eight samples were genotyped as genotype 1, subtypes 1a (62.5%) and 1b (31.3%), and two samples (6.2%) were genotype 3, subtype 3a. These data show a high prevalence of HCV infection and low ALT levels in the studied population. The risk factor analysis findings emphasize the importance of public health strategies such as anti-HCV screening of candidate blood and organ donors, in addition to the stricter adoption of hemodialysis-specific infection control measures. The present study also demonstrates that HCV genotype 1 (subtype 1a) is predominant in this populatio

Antimicrobial Activity of Silver Camphorimine Complexes against Candida Strains

Hydroxide [Ag(OH)L] (L = IVL, VL, VIL, VIIL), oxide [{AgL}2}(μ-O)] (L = IL, IIL, IIIL, VL, VIL) or chloride [AgIIL]Cl, [Ag(VIL)2]Cl complexes were obtained from reactions of mono- or bicamphorimine derivatives with Ag(OAc) or AgCl. The new complexes were characterized by spectroscopic (NMR, FTIR) and elemental analysis. X-ray photoelectron spectroscopy (XPS), ESI mass spectra and conductivity measurements were undertaken to corroborate formulations. The antimicrobial activity of complexes and some ligands were evaluated towards Candida albicans and Candida glabrata, and strains of the bacterial species Escherichia coli, Burkholderia contaminans, Pseudomonas aeruginosa and Staphylococcus aureus based on the Minimum Inhibitory Concentrations (MIC). Complexes displayed very high activity against the Candida species studied with the lowest MIC values (3.9 µg/mL) being observed for complexes 9 and 10A against C. albicans. A significant feature of these redesigned complexes is their ability to sensitize C. albicans, a trait that was not found for the previously investigated [Ag(NO3)L] complexes. The MIC values of the complexes towards bacteria were in the range of those of [Ag(NO3)L] and well above those of the precursors Ag(OAc) or AgCl. The activity of the complexes towards normal fibroblasts V79 was evaluated by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Results showed that the complexes have a significant cytotoxicity

Periods of constant and falling-rate for infrared drying of carrot slices Períodos de secagem constante e decrescente de fatias de cenoura por infravermelho

The aim of this work was to study the infrared drying process of carrot slices and to determine coefficients related to the heat and mass transfer of the process. Fresh carrots were used, dried until constant weight in a dryer with infrared heating source. Different models were utilized to fit the experimental data of constant and falling drying rate periods. It was verified that the coefficients of heat and mass transfer, during the constant drying rate, significantly increased with temperature on rise. The Diffusion Approximation, Two Terms, Midili and Verna models satisfactory represented the falling period of drying rate of carrot slices. The effective diffusion coefficient increased with temperature and this relationship can be represented by the Arrhenius equation, obtaining activation energy to the drying process of 29.092 kJ mol-1.<br>Com este trabalho objetivou-se estudar o processo de secagem por infravermelho das fatias de cenoura e determinar alguns coeficientes referentes à transferência de calor e massa do processo. Utilizaram-se cenouras frescas, secadas até massa constante em um secador com fonte de aquecimento por infravermelho. Aos dados experimentais se ajustaram diferentes modelos para os períodos de taxa de secagem constante e decrescentes. Verificou-se que os coeficientes transferência de calor e massa, referentes ao período de secagem constante, aumentaram significativamente com o aumento da temperatura e que os modelos Aproximação da Difusão, Dois Termos, Midili e Verna representaram satisfatoriamente o período de secagem decrescente das fatias de cenoura. O coeficiente de difusão efetivo aumentou com a temperatura e esta relação pode ser representada pela Equação de Arrhenius, obtendo-se uma energia de ativação para o processo de secagem de 29,092 kJ mol-1

Avô imigrante, pai lavrador, neto cafeicultor: análise de trajetórias intergeracionais na América Portuguesa (séculos XVIII e XIX)

O presente artigo tem como ponto de partida o acompanhamento de três trajetórias individuais inseridas no contexto da história de Minas Gerais, entre os séculos XVIII e XIX. Analisaremos as formas de ascensão social e o processo de diferenciação desses indivíduos uma vez que suas origens não se prendiam às carreiras clássicas dos conquistadores, homens de negócios e burocratas. Ao longo prazo, estas trajetórias resultaram na integração dessas gerações a elite rural do sudeste brasileiro.The present article has as its starting point the following of three individual trajectories placed in the context of the history of Minas Gerais, between the 18th and 19th Centuries. We will analyze the forms of social ascension and the process of differentiation of these individuals since their origins did not stick to the classic carriers of the conquerors, business men and bureaucrats. In the long term, these trajectories resulted in the integration of these generations with the rural elite of the southeast region of Brazil