Base de dados : MEDLINE
Pesquisa : B01.650.940.800.575.912.250.618.100.050.060.600 [Categoria DeCS]
Referências encontradas : 1783 [refinar]
Mostrando: 1 .. 10   no formato [Longo]

página 1 de 179 ir para página                         

  1 / 1783 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:29329094
Autor:Sentkowska A; Pyrzynska K
Endereço:University of Warsaw, Heavy Ion Laboratory, Pasteura 5A, 02-093 Warsaw, Poland. Electronic address: sentkowska@slcj.uw.edu.pl.
Título:Hydrophilic interaction liquid chromatography in the speciation analysis of selenium.
Fonte:J Chromatogr B Analyt Technol Biomed Life Sci; 1074-1075:8-15, 2018 Feb 01.
ISSN:1873-376X
País de publicação:Netherlands
Idioma:eng
Resumo:The hydrophilic interaction liquid chromatography (HILIC) coupled to mass spectrometry was employed to study retention behavior of selected selenium compounds using two different HILIC stationary phases: silica and zwitterionic. Two organic solvents - acetonitrile and methanol - were compared as a component of mobile phase. Separation parameters such as a content of organic modifier, the eluent pH and inorganic buffer concentration were investigated. Based on all observations, methanol seems to be beneficial for the separation of studied compounds. The optimal HILIC separation method involved silica column and eluent composed of 85% MeOH and CH COONH (8 mM, pH 7) was compared to RP method in terms of time of the single run, the separation efficiency and limit of detection.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Acetonitriles); 0 (Plant Extracts); 0 (Selenium Compounds); H6241UJ22B (Selenium); Y4S76JWI15 (Methanol); Z072SB282N (acetonitrile)


  2 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28503942
Autor:Wang ZD; Li LH; Xia H; Wang F; Yang LG; Wang SK; Sun GJ
Endereço:a Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, and Department of Nutrition & Food Hygiene, School of Public Health , Southeast University , Nanjing , China.
Título:Optimisation of steam distillation extraction oil from onion by response surface methodology and its chemical composition.
Fonte:Nat Prod Res; 32(1):112-115, 2018 Jan.
ISSN:1478-6427
País de publicação:England
Idioma:eng
Resumo:Oil extraction from onion was performed by steam distillation. Response surface methodology was applied to evaluate the effects of ratio of water to raw material, extraction time, zymolysis temperature and distillation times on yield of onion oil. The maximum extraction yield (1.779%) was obtained as following conditions: ratio of water to raw material was 1, extraction time was 2.5 h, zymolysis temperature was 36° and distillation time was 2.6 h. The experimental values agreed well with those predicted by regression model. The chemical composition of extracted onion oil under the optimum conditions was analysed by gas chromatography-mass spectrometry technology. The results showed that sulphur compounds, like alkanes, sulphide, alkenes, ester and alcohol, were the major components of onion oil.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Plant Oils); 0 (Steam); 0 (Sulfides); 059QF0KO0R (Water); 4P3VLD98FL (onion oil)


  3 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:29287997
Autor:Machado KDC; Sousa LQ; Lima DJB; Soares BM; Cavalcanti BC; Maranhão SS; Noronha JDC; Rodrigues DJ; Militão GCG; Chaves MH; Vieira-Júnior GM; Pessoa C; Moraes MO; Sousa JMCE; Melo-Cavalcante AAC; Ferreira PMP
Endereço:Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, Brazil.
Título:Marinobufagin, a molecule from poisonous frogs, causes biochemical, morphological and cell cycle changes in human neoplasms and vegetal cells.
Fonte:Toxicol Lett; 285:121-131, 2018 Mar 15.
ISSN:1879-3169
País de publicação:Netherlands
Idioma:eng
Resumo:Skin toad secretion present physiologically active molecules to protect them against microorganisms, predators and infections. This work detailed the antiproliferative action of marinobufagin on tumor and normal lines, investigate its mechanism on HL-60 leukemia cells and its toxic effects on Allium cepa meristematic cells. Initially, cytotoxic action was assessed by colorimetric assays. Next, HL-60 cells were analyzed by morphological and flow cytometry techniques and growing A. cepa roots were examined after 72 h exposure. Marinobufagin presented high antiproliferative action against all human tumor lines [IC values ranging from 0.15 (leukemia) to 7.35 (larynx) µM] and it failed against human erythrocytes and murine lines. Human normal peripheral blood mononuclear cells (PBMC) were up to 72.5-fold less sensitive [IC 10.88 µM] to marinobufagin than HL-60 line, but DNA strand breaks were no detected. Leukemia treaded cells exhibited cell viability reduction, DNA fragmentation, phosphatidylserine externalization, binucleation, nuclear condensation and cytoplasmic vacuoles. Marinobufagin also reduced the growth of A. cepa roots (EC : 7.5 µM) and mitotic index, caused cell cycle arrest and chromosomal alterations (micronuclei, delays and C-metaphases) in meristematic cells. So, to find out partially targeted natural molecules on human leukemia cells, like marinobufagin, is an amazing and stimulating way to continue the battle against cancer.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antineoplastic Agents); 0 (Bufanolides); 3KBT25GV2B (marinobufagenin)


  4 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28941906
Autor:Yang Z; Chambers H; DiCaprio E; Gao G; Li J
Endereço:Department of Biology, College of Life Science, Huzhou University, Huzhou, Zhejiang, China.
Título:Internalization and dissemination of human norovirus and Tulane virus in fresh produce is plant dependent.
Fonte:Food Microbiol; 69:25-32, 2018 Feb.
ISSN:1095-9998
País de publicação:England
Idioma:eng
Resumo:Human norovirus (NoV) is a leading cause of fresh produce associated outbreaks. Previous research indicates that the roots of growing leafy greens and berries internalize human NoV. However the effect of plant type and inoculum level on internalization rates has not been directly compared. In this study we compared the internalization and dissemination rates of human NoV and its surrogate, Tulane virus (TV) in green onion, radishes, and Romaine lettuce. We also evaluated the effect inoculum level and plant growth matrix on the rate of viral internalization. In the hydroponic growth system, we detected internalization and dissemination of human NoV RNA in green onions. In hydroponically growing green onions inoculated with high titer TV, we found higher rates of internalization and dissemination compared to green onions inoculated with low titer TV. In soil growth systems, no infectious TV was detected in either green onion or radishes. However, in Romaine lettuce plants grown in soil approximately 4 log PFU/g was recovered from all tissues on day 14 p.i. Overall, we found that the type of plant, growth matrix, and the inoculum level influences the internalization and dissemination of human NoV and TV.
Tipo de publicação: JOURNAL ARTICLE


  5 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28573682
Autor:Yu J; Zhang S; Zhang L
Endereço:School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China.
Título:Evaluation of the extent of initial Maillard reaction during cooking some vegetables by direct measurement of the Amadori compounds.
Fonte:J Sci Food Agric; 98(1):190-197, 2018 Jan.
ISSN:1097-0010
País de publicação:England
Idioma:eng
Resumo:BACKGROUND: During vegetable cooking, one of the most notable and common chemical reactions is the Maillard reaction, which occurs as a result of thermal treatment and dehydration. Amadori compound determination provides a very sensitive indicator for early detection of quality changes caused by the Maillard reaction, as well as to retrospectively assess the heat treatment or storage conditions to which the product has been subjected. In this paper, a hydrophilic interaction liquid chromatographic-electrospray ionization-tandem mass spectrometric method was developed for the analysis of eight Amadori compounds, and the initial steps of the Maillard reaction during cooking (steaming, frying and baking) bell pepper, red pepper, yellow onion, purple onion, tomato and carrot were also assessed by quantitative determination of these Amadori compounds. RESULTS: These culinary treatments reduced moisture and increased the total content of Amadori compounds, which was not dependent on the type of vegetable or cooking method. Moreover, the effect of steaming on Amadori compound content and water loss was less than that by baking and frying vegetables. Further studies showed that the combination of high temperature and short time may lead to lower formation of Amadori compounds when baking vegetables. CONCLUSION: Culinary methods differently affected the extent of initial Maillard reaction when vegetables were made into home-cooked products. © 2017 Society of Chemical Industry.
Tipo de publicação: EVALUATION STUDIES; JOURNAL ARTICLE
Nome de substância:0 (Plant Extracts)


  6 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28735238
Autor:Matos LA; Cunha ACS; Sousa AA; Maranhão JPR; Santos NRS; Gonçalves MMC; Dantas SMMM; Sousa JMCE; Peron AP; Silva FCCD; Alencar MVOB; Islam MT; Aguiar RPS; Melo-Cavalcante AAC; Bonecker CC; Junior HFJ
Endereço:Departamento de Ciências Biológicas, Universidade Federal do Piauí, Campus Ministro Petrônio Portela, Av. Universitária, CEP - 64.049-550, Brazil.
Título:The influence of heavy metals on toxicogenetic damage in a Brazilian tropical river.
Fonte:Chemosphere; 185:852-859, 2017 Oct.
ISSN:1879-1298
País de publicação:England
Idioma:eng
Resumo:Anthropogenic activities in tropical rivers favor the eutrophication process, which causes increased concentration of heavy metals. The presence and bioaccumulation of metals are directly related to the presence of genotoxic damage in aquatic organisms. Thus, we evaluated the presence of heavy metals (Fe, Zn, Cr, Cu and Al) and performed toxicogenetic tests in surface (S) and bottom (B) of water samples of the Poti river (Piaui/Brazil). Cytotoxicity and genotoxicity tests were performed in Allium cepa, and micronucleus (MN) and comet assay were performed in Oreochromis niloticus. The chemical analysis showed concentrations above the limit for Cu, Cr, Fe and Al according to Brazilian laws, characterizing anthropogenic disturbance in this aquatic environment. Toxicogenetic analysis presented significant cytotoxic, mutagenic and genotoxic effects in different exposure times and water layers (S and B), especially alterations in mitotic spindle defects, MN formations, nuclear bud and DNA strand breaks. Correlations between Fe and cytotoxicity, and Al and mutagenicity were statistically significant and point out to the participation of heavy metals in genotoxic damage. Therefore, Poti river water samples presented toxicogenetic effects on all bioindicators analyzed, which are most likely related to heavy metals pollution.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Metals, Heavy); 0 (Mutagens); 0 (Water Pollutants, Chemical)


  7 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28708375
Autor:Silvaroli JA; Pleshinger MJ; Banerjee S; Kiser PD; Golczak M
Endereço:Department of Pharmacology, School of Medicine, Case Western Reserve University , Cleveland, Ohio, United States.
Título:Enzyme That Makes You Cry-Crystal Structure of Lachrymatory Factor Synthase from Allium cepa.
Fonte:ACS Chem Biol; 12(9):2296-2304, 2017 Sep 15.
ISSN:1554-8937
País de publicação:United States
Idioma:eng
Resumo:The biochemical pathway that gives onions their savor is part of the chemical warfare against microbes and animals. This defense mechanism involves formation of a volatile lachrymatory factor (LF) ((Z)-propanethial S-oxide) that causes familiar eye irritation associated with onion chopping. LF is produced in a reaction catalyzed by lachrymatory factor synthase (LFS). The principles by which LFS facilitates conversion of a sulfenic acid substrate into LF have been difficult to experimentally examine owing to the inherent substrate reactivity and lability of LF. To shed light on the mechanism of LF production in the onion, we solved crystal structures of LFS in an apo-form and in complex with a substrate analogue, crotyl alcohol. The enzyme closely resembles the helix-grip fold characteristic for plant representatives of the START (star-related lipid transfer) domain-containing protein superfamily. By comparing the structures of LFS to that of the abscisic acid receptor, PYL10, a representative of the START protein superfamily, we elucidated structural adaptations underlying the catalytic activity of LFS. We also delineated the architecture of the active site, and based on the orientation of the ligand, we propose a mechanism of catalysis that involves sequential proton transfer accompanied by formation of a carbanion intermediate. These findings reconcile chemical and biochemical information regarding thioaldehyde S-oxide formation and close a long-lasting gap in understanding of the mechanism responsible for LF production in the onion.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Butanols); 0 (Sulfoxides); 94Z73U61UH (thiopropanal S-oxide); D7F26UNN0B (crotonyl alcohol); EC 5.3.- (Intramolecular Oxidoreductases); EC 5.3.- (lachrymatory factor synthase, Allium cepa)


  8 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28646437
Autor:Becaro AA; Siqueira MC; Puti FC; de Moura MR; Correa DS; Marconcini JM; Mattoso LHC; Ferreira MD
Endereço:Programa de Pós-Graduação em Biotecnologia (PPGBiotec), Centro de Ciências Exatas e Tecnologia, Universidade Federal de São Carlos (UFSCar), São Carlos, SP, 13565-905, Brazil.
Título:Cytotoxic and genotoxic effects of silver nanoparticle/carboxymethyl cellulose on Allium cepa.
Fonte:Environ Monit Assess; 189(7):352, 2017 Jul.
ISSN:1573-2959
País de publicação:Netherlands
Idioma:eng
Resumo:Several mutagenic agents may be present in substances released in the environment, which may cause serious environmental impacts. Among these substances, there is a special concern regarding the widespread use of silver nanoparticles (AgNP) in several products due to their widely known bactericidal properties, including in the medical field and the food industry (e.g., active packaging). The assessment of the effects of AgNP released in the environment, having different concentrations, sizes, and being associated or not to other types of materials, including polymers, is therefore essential. In this research, the objective was to evaluate the genotoxic and cytotoxic effects of AgNP (size range between 2 and 8 nm) on root meristematic cells of Allium cepa (A. cepa). Tests were carried out in the presence of colloidal solution of AgNP and AgNP mixed with carboxymethylcellulose (CMC), using distinct concentrations of AgNP. As a result, when compared to control samples, AgNP induced a mitotic index decrease and an increase of chromosomal aberration number for two studied concentrations. When AgNP was in the presence of CMC, no cytotoxic potential was verified, but only the genotoxic potential for AgNP dispersion having concentration of 12.4 ppm.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Mutagens); 3M4G523W1G (Silver); K679OBS311 (Carboxymethylcellulose Sodium)


  9 / 1783 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28612608
Autor:Ren F; Reilly K; Kerry JP; Gaffney M; Hossain M; Rai DK
Endereço:Teagasc Food Research Centre , Ashtown, Dublin D15 KN3K, Ireland .
Título:Higher Antioxidant Activity, Total Flavonols, and Specific Quercetin Glucosides in Two Different Onion (Allium cepa L.) Varieties Grown under Organic Production: Results from a 6-Year Field Study.
Fonte:J Agric Food Chem; 65(25):5122-5132, 2017 Jun 28.
ISSN:1520-5118
País de publicação:United States
Idioma:eng
Resumo:We carried out a 6-year study to assess the effect of conventional, organic, and mixed cultivation practices on bioactive compounds (flavonoids, anthocyanins) and antioxidant capacity in onion. Total flavonoids, total anthocyanins, individual flavonols, individual anthocyanins, and antioxidant activity were measured in two varieties ('Hyskin' and 'Red Baron') grown in a long-term split-plot factorial systems comparison trial. This is the first report of repeated measurements of bioactive content over an extensive time period in a single crop type within the same trial. Antioxidant activity (DPPH and FRAP), total flavonol content, and levels of Q 3,4' D and Q 3 G were higher in both varieties under fully organic compared to fully conventional management. Total flavonoids were higher in 'Red Baron' and when onions were grown under organic soil treatment. Differences were primarily due to different soil management practices used in organic agriculture rather than pesticide/ herbicide application.
Tipo de publicação: COMPARATIVE STUDY; JOURNAL ARTICLE
Nome de substância:0 (Antioxidants); 0 (Flavonols); 0 (Glucosides); 0 (Plant Extracts); 9IKM0I5T1E (Quercetin)


  10 / 1783 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
PMID:28605976
Autor:Mansour HA; Mahfouz H; Maher N
Endereço:Botany Department, Faculty of Science, Ain Shams University , Abassia, Cairo , Egypt.
Título:Anti-mutagenic potential of algal extracts on chromosomal aberrations in Allium cepa L.
Fonte:Acta Biol Hung; 68(2):137-149, 2017 Jun.
ISSN:0236-5383
País de publicação:Hungary
Idioma:eng
Resumo:In the present study, sodium azide (SA) toxicity and the anti-mutagenic effects of different algal extracts at 0.1% and 0.2% concentrations were studied on the mitotic index (MI), chromosomal and nuclear aberrations using Allium cepa L. root assay. Moreover, phytochemical screening of photosynthetic pigments, antioxidants compounds, total antioxidant, DPPH scavenging activity, polysaccharides, and phenolic contents were done for two red seaweeds (Laurencia obtusa (Hudson) Lamouroux and Polysiphonia morrowii Harvey) and for one brown seaweed (Dictyopteris delicatula Lamouroux). Treatment with 300 µg/ml sodium azide (SA) induced the highest number of aberrations in A. cepa root. A highly significant decrease in the MI appeared after treatment with SA, whereas its value increased following different algal extracts treatments. The highest anti-mutagenic inhibition activity of Dictyopteris delicatula added at 0.2% concentration was 72.96%, 69.84%, 56.89% and 43.59% with the algal polyphenol, polysaccharide, aqueous and methanol extract treatments, respectively. The different algal extracts minimized the genotoxicity and exhibited anti-mutagenic potential against SA in a dose-dependent manner. Phytochemical studies showed that Dictyopteris delicatula contained the highest total phenol, chlorophyll-a and carotenoid quantity. Moreover it exhibited the highest total antioxidant and DPPH scavenging activities. Total polysaccharides and the weight percentage of sulphated polysaccharides were relatively higher in Polysiphonia morrowii followed by Laurencia obtusa. Hydroquinone and bromophenol were detected only in the studied brown and red seaweeds, respectively. Polysiphonia morrowii and Laurencia obtusa contained the highest quantity of galactose, rhmnose and xylose, while Dictyopteris delicatula contained fucose and mannitol as main monosaccharide units. In conclusion, the studied seaweeds may be considered as rich sources of natural antioxidants. Meanwhile the investigated different algal extracts can minimize the genotoxicity in a dose-dependent manner and exhibit anti-mutagenic potential against the mutagenic substance sodium azide.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antimutagenic Agents); 0 (Free Radical Scavengers); 0 (Plant Extracts); 968JJ8C9DV (Sodium Azide)



página 1 de 179 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde