Base de dados : MEDLINE
Pesquisa : D02.355.071 [Categoria DeCS]
Referências encontradas : 1018 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 102 ir para página                         

  1 / 1018 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28425292
[Au] Autor:Silva GH; Zeraik ML; de Oliveira CM; Teles HL; Trevisan HC; Pfenning LH; Nicolli CP; Young MCM; Mascarenhas YP; Abreu LM; Saraiva AC; Medeiros AI; Bolzani VDS; Araujo AR
[Ad] Endereço:Instituto de Ciências Exatas e Tecnológicas, Universidade Federal de Viçosa , Rio Paranaíba, Minas Gerais 38810-000, Brazil.
[Ti] Título:Lactone Derivatives Produced by a Phaeoacremonium sp., an Endophytic Fungus from Senna spectabilis.
[So] Source:J Nat Prod;80(5):1674-1678, 2017 May 26.
[Is] ISSN:1520-6025
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Three new isoaigialones, A, B, and C (1-3), along with aigialone (4), were isolated from the crude EtOAc extract of a Phaeoacremonium sp., an endophytic fungus obtained from the leaves of Senna spectabilis. The structures of these compounds were elucidated based on the analysis of spectroscopic data. Compounds 2 and 4 were active against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum. This is the first report of metabolites produced by an Phaeoacremonium sp., associated with S. spectabilis.
[Mh] Termos MeSH primário: Acetais/isolamento & purificação
Acetais/farmacologia
Antifúngicos/isolamento & purificação
Antifúngicos/farmacologia
Ascomicetos/química
Cladosporium/química
Cetonas/isolamento & purificação
Cetonas/farmacologia
Lactonas/isolamento & purificação
Folhas de Planta/química
Senna (Planta)/química
[Mh] Termos MeSH secundário: Acetais/química
Antifúngicos/química
Cetonas/química
Lactonas/química
Lactonas/metabolismo
Lactonas/farmacologia
Estrutura Molecular
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Antifungal Agents); 0 (Ketones); 0 (Lactones); 0 (aigialone); 0 (isoaigialone A); 0 (isoaigialone B); 0 (isoaigialone C)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170925
[Lr] Data última revisão:
170925
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170421
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jnatprod.5b00828


  2 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28359674
[Au] Autor:Innocenti R; Lenci E; Menchi G; Pupi A; Trabocchi A
[Ad] Endereço:Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 13, 50019 Sesto Fiorentino, Florence, Italy.
[Ti] Título:Design and synthesis of bicyclic acetals as Beta Secretase (BACE1) inhibitors.
[So] Source:Bioorg Med Chem;25(19):5077-5083, 2017 Oct 01.
[Is] ISSN:1464-3391
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Taking advantage of the structural similarity between aspartic proteases, small-molecule peptidomimetic inhibitors that already showed activity towards Secreted Aspartic Protease 2 as anti-Candida agents and HIV protease inhibitors were exploited as potential BACE1 inhibitors. A focused library of 6,8-dioxa-3-azabicyclo[3.2.1]-octane peptidomimetic scaffolds was synthesized and assayed towards BACE1 enzyme, resulting in the identification of a thiolactam-containing hit compound possessing IC in the low micromolar range, and confirming the bicyclic acetal portion as a potential transition state analogue in the interaction with catalytic aspartic acid residues.
[Mh] Termos MeSH primário: Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores
Ácido Aspártico Endopeptidases/antagonistas & inibidores
Compostos Azabicíclicos/química
Compostos Azabicíclicos/farmacologia
Inibidores Enzimáticos/química
Inibidores Enzimáticos/farmacologia
Peptidomiméticos/química
Peptidomiméticos/farmacologia
[Mh] Termos MeSH secundário: Acetais/síntese química
Acetais/química
Acetais/farmacologia
Sequência de Aminoácidos
Secretases da Proteína Precursora do Amiloide/química
Secretases da Proteína Precursora do Amiloide/metabolismo
Ácido Aspártico Endopeptidases/química
Ácido Aspártico Endopeptidases/metabolismo
Compostos Azabicíclicos/síntese química
Desenho de Drogas
Inibidores Enzimáticos/síntese química
Inibidores da Protease de HIV/química
Inibidores da Protease de HIV/farmacologia
Seres Humanos
Simulação de Acoplamento Molecular
Peptidomiméticos/síntese química
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Azabicyclo Compounds); 0 (Enzyme Inhibitors); 0 (HIV Protease Inhibitors); 0 (Peptidomimetics); EC 3.4.- (Amyloid Precursor Protein Secretases); EC 3.4.23.- (Aspartic Acid Endopeptidases); EC 3.4.23.46 (BACE1 protein, human)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171016
[Lr] Data última revisão:
171016
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170401
[St] Status:MEDLINE


  3 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28032267
[Au] Autor:Brandt K; Dötterl S; Francke W; Ayasse M; Milet-Pinheiro P
[Ad] Endereço:Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.
[Ti] Título:Flower Visitors of Campanula: Are Oligoleges More Sensitive to Host-Specific Floral Scents Than Polyleges?
[So] Source:J Chem Ecol;43(1):4-12, 2017 Jan.
[Is] ISSN:1573-1561
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The pollen diet provided by adult bees to their offspring varies immensely. While some species collect pollen on several plants irrespective of their phylogenetic relatedness (polyleges), others collect only on plants within a genus or family (oligoleges). Floral scents play a central role in bee-plant interactions. To locate flowers, polyleges are assumed to rely on compounds commonly found as floral scent constituents, whereas oligoleges rely on unusual compounds to recognize host flowers unambiguously. Campanula flowers are visited by both polylectic and oligolectic species, and their scent bouquets consist of common and unusual (e.g., spiroacetals) volatiles. In a comparative approach, we performed electroantennographic analyses to investigate the antennal responses of three polyleges and three oligoleges to three common volatiles and four spiroacetals. We hypothesized that: 1) oligoleges and polyleges should respond similarly to common flower volatiles, and 2) Campanula oligoleges should be more sensitive to spiroacetals than are polyleges. In corroboration, we found that antennal sensitivity to common volatiles was similar among bees irrespective of pollen diet, whereas oligoleges of Campanula were more sensitive to spiroacetals than polyleges. Newly emerged bees of the Campanula oligolege Chelostoma rapunculi rely on spiroacetals for recognizing host-flowers, and our results suggest that this might also be true for other Campanula oligoleges, since Chelostoma campanularum and Hoplitis mitis also were able to perceive these specific volatiles at very low concentrations. Together, our results provide interesting insights into the significance of olfactory adaptations in oligolectic and polylectic bee species.
[Mh] Termos MeSH primário: Abelhas/fisiologia
Campanulaceae
Flores/química
Odorantes/análise
Polinização
[Mh] Termos MeSH secundário: Acetais/análise
Animais
Antenas de Artrópodes/fisiologia
Fenômenos Eletrofisiológicos
Feminino
Especificidade da Espécie
Compostos de Espiro/análise
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Spiro Compounds)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161230
[St] Status:MEDLINE
[do] DOI:10.1007/s10886-016-0802-z


  4 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27995365
[Au] Autor:Mitchell RF; Curkovic T; Mongold-Diers JA; Neuteboom L; Galbrecht HM; Tröger A; Bergmann J; Francke W; Hanks LM
[Ad] Endereço:Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. mitchellr@uwosh.edu.
[Ti] Título:Evidence that Cerambycid Beetles Mimic Vespid Wasps in Odor as well as Appearance.
[So] Source:J Chem Ecol;43(1):75-83, 2017 Jan.
[Is] ISSN:1573-1561
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We present evidence that cerambycid species that are supposed mimics of vespid wasps also mimic their model's odor by producing spiroacetals, common constituents of vespid alarm pheromones. Adults of the North American cerambycids Megacyllene caryae (Gahan) and Megacyllene robiniae (Forster) are conspicuously patterned yellow and black, and are believed to be mimics of aculeate Hymenoptera, such as species of Vespula and Polistes. Adult males of M. caryae produce an aggregation-sex pheromone, but both sexes produce a pungent odor when handled, which has been assumed to be a defensive response. Headspace aerations of agitated females of M. caryae contained 16 compounds with mass spectra characteristic of spiroacetals of eight distinct chemical structures, with the dominant compound being (7E,2E)-7-ethyl-2-methyl-1,6-dioxaspiro[4.5]decane. Headspace samples of agitated males of M. caryae contained five of the same components, with the same dominant compound. Females of M. robiniae produced six different spiroacetals, one of which was not produced by M. caryae, (2E,7E)-2-ethyl-7-methyl-1,6-dioxaspiro[4.5]decane, and five that were shared with M. caryae, including the dominant (2E,8E)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane. The latter compound is the sole spiroacetal produced by both males and females of a South American cerambycid species, Callisphyris apicicornis (Fairmaire & Germain), which is also thought to be a wasp mimic. Preliminary work also identified spiroacetals of similar or identical structure released by vespid wasps that co-occur with the Megacyllene species.
[Mh] Termos MeSH primário: Mimetismo Biológico
Coleópteros/metabolismo
Odorantes/análise
Vespas/metabolismo
[Mh] Termos MeSH secundário: Acetais/análise
Acetais/metabolismo
Animais
Feminino
Masculino
Feromônios/análise
Feromônios/metabolismo
Compostos de Espiro/análise
Compostos de Espiro/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Pheromones); 0 (Spiro Compounds)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161221
[St] Status:MEDLINE
[do] DOI:10.1007/s10886-016-0800-1


  5 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27834880
[Au] Autor:Asare-Nkansah S; Wünsch B
[Ad] Endereço:Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms-Universität Münster, Corrensstraße 48, D-48149 Münster, Germany. asn12002@yahoo.com.
[Ti] Título:Double Intramolecular Transacetalization of Polyhydroxy Acetals: Synthesis of Conformationally-Restricted 1,3-Dioxanes with Axially-Oriented Phenyl Moiety.
[So] Source:Molecules;21(11), 2016 Nov 09.
[Is] ISSN:1420-3049
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:The synthesis of conformationally-restricted 1,3-dioxanes with a phenyl moiety fixed in an axial orientation at the acetalic center is described. Starting with diethyl 3-hydroxyglutarate ( ), benzaldehyde acetal and acetophenone ketal bearing a protected 1,3,5-trihydroxypentyl side chain in the -position were prepared. The first acid-catalyzed intramolecular transacetalization gave a mixture of diastereomeric 2-benzofurans (ratio of diastereomers 2:2:1:1). After OH group deprotection, the second intramolecular transacetalization afforded tricyclic alcohol (2-(1,5-epoxy-1,3,4,5-tetrahydro-2-benzoxepin-3-yl]ethan-1-ol). Analogous cyclizations led to the corresponding silyl ether (19%) and azide (13%). Whereas tricyclic alcohol was obtained as a 1:1 mixture of diastereomers, the silyl ether and the azide afforded only one diastereomer. This observation indicates a faster cyclization of the minor diastereomers providing the thermodynamically-favored compounds with equatorially-oriented substituents in the 3-position of the tricyclic 1,5-epoxy-2-benzoxepine system. In general, acetophenone-derived ketalic compounds ( -series) required very mild reaction conditions and gave lower yields than the corresponding acetalic compounds ( -series).
[Mh] Termos MeSH primário: Acetais/química
Dioxanos/química
Dioxanos/síntese química
[Mh] Termos MeSH secundário: Acetilação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Dioxanes)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170407
[Lr] Data última revisão:
170407
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161112
[St] Status:MEDLINE


  6 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27543351
[Au] Autor:Chen N; Collier MA; Gallovic MD; Collins GC; Sanchez CC; Fernandes EQ; Bachelder EM; Ainslie KM
[Ad] Endereço:Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, NC, USA.
[Ti] Título:Degradation of acetalated dextran can be broadly tuned based on cyclic acetal coverage and molecular weight.
[So] Source:Int J Pharm;512(1):147-157, 2016 Oct 15.
[Is] ISSN:1873-3476
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Microparticles (MPs) derived from acid-sensitive biopolymers enable rapid degradation and cargo release under acidic conditions, such as at tumor microenvironments, within lysosomal/phagosomal compartments inside phagocytic cells, or at sites of inflammation. One such acid-sensitive biopolymer, acetalated dextran (Ace-DEX), has tunable degradation rates and pH-neutral degradation byproducts consisting of dextran, acetone, and ethanol. By studying the degradation profiles of Ace-DEX MPs with varying cyclic acetal coverage (CAC) and dextran molecular weight (MW), we concluded that MPs composed of low CAC or high MW polymer degraded the fastest at both pH 7.4 and 5.0. To further understand the properties of this unique polymer, we encapsulated a model drug resiquimod, which is a toll-like receptor (TLR) 7/8 agonist, into Ace-DEX MPs of different polymer CAC and dextran MW. It was observed that resiquimod was released faster from MPs of lower CAC or higher MW. By evaluating the activation of RAW macrophages cultured with different types of resiquimod-loaded Ace-DEX MPs, we found that MPs of lower CAC or higher MW promoted greater nitrite production and resulted in more robust cell activation. Our results indicate we can precisely control the degradation profile, release kinetics, and bioactivity of encapsulated cargos by altering CAC and MW, furthering Ace-DEX MPs' novelty as a drug carrier.
[Mh] Termos MeSH primário: Acetais/química
Acetais/farmacocinética
Dextranos/química
Dextranos/farmacocinética
[Mh] Termos MeSH secundário: Sobrevivência Celular/efeitos dos fármacos
Células Cultivadas
Liberação Controlada de Fármacos
Concentração de Íons de Hidrogênio
Imidazóis/química
Imidazóis/farmacocinética
Imidazóis/farmacologia
Macrófagos/efeitos dos fármacos
Peso Molecular
Polímeros/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Dextrans); 0 (Imidazoles); 0 (Polymers); V3DMU7PVXF (resiquimod)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160821
[St] Status:MEDLINE


  7 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27341397
[Au] Autor:Gonzalez C; Kavoosi S; Sanchez A; Wnuk SF
[Ad] Endereço:Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA.
[Ti] Título:Reduction of sugar lactones to hemiacetals with lithium triethylborohydride.
[So] Source:Carbohydr Res;432:17-22, 2016 Sep 02.
[Is] ISSN:1873-426X
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Reduction of ribono-1,4-lactones and gulono-1,4-lactone as well as ribono-1,5-lactone and glucono-1,5-lactones with LTBH (1.2 equiv.) in CH2Cl2 at 0 °C for 30 min provided the corresponding pentose or hexose hemiacetals in high yields. Commonly used in carbohydrate chemistry protecting groups such as trityl, benzyl, silyl, acetals and to some extent acyls are compatible with this reduction.
[Mh] Termos MeSH primário: Acetais/síntese química
Gluconatos/química
Lactonas/química
Ribose/análogos & derivados
[Mh] Termos MeSH secundário: Acetais/química
Boroidretos/química
Lítio/química
Estrutura Molecular
Oxirredução
Ribose/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Borohydrides); 0 (Gluconates); 0 (Lactones); 3327-63-7 (ribonolactone); 681HV46001 (Ribose); 9FN79X2M3F (Lithium); WQ29KQ9POT (beta-glucono-1,5-lactone)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170902
[Lr] Data última revisão:
170902
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160625
[St] Status:MEDLINE


  8 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27213304
[Au] Autor:Guidi S; Noè M; Riello P; Perosa A; Selva M
[Ad] Endereço:Department of Molecular Sciences and Nanosystems, Centre for Sustainable Technologies, Ca' Foscari University of Venice, Via Torino 155, 30175 Venezia Mestre, Italy. sandro.guidi@unive.it.
[Ti] Título:Towards a Rational Design of a Continuous-Flow Method for the Acetalization of Crude Glycerol: Scope and Limitations of Commercial Amberlyst 36 and AlF3·3H2O as Model Catalysts.
[So] Source:Molecules;21(5), 2016 May 18.
[Is] ISSN:1420-3049
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:The acetalization of six different types of glycerol including pure, wet, and crude-like grade compounds of compositions simulating those of crude glycerols produced by the biodiesel manufacture, was carried out with two model ketones such as acetone and 2-butanone. The reaction was investigated under continuous-flow (CF) conditions through a comparative analysis of an already known acetalization catalyst such as Amberlyst 36 (A36), and aluminum fluoride three hydrate (AlF3·3H2O, AF) whose use was never previously reported for the synthesis of acetals. At 10 bar and 25 °C, A36 was a highly active catalyst allowing good-to-excellent conversion (85%-97%) and selectivity (99%) when either pure or wet glycerol was used as a reagent. This catalyst however, proved unsuitable for the CF acetalization of crude-like glycerol (CG) since it severely and irreversibly deactivated in a few hours by the presence of low amounts of NaCl (2.5 wt %) which is a typical inorganic impurity of raw glycerol from the biorefinery. Higher temperature and pressure (up to 100 °C and 30 bar) were not successful to improve the outcome. By contrast, at 10 bar and 100 °C, AF catalyzed the acetalization of CG with both acetone and 2-butanone, yielding stable conversion and productivity up to 78% and 5.6 h(-1), respectively. A XRD analysis of fresh and used catalysts proved that the active phase was a solid solution (SS) of formula Al2[F1-x(OH)x]6(H2O)y present as a component of the investigated commercial AF sample. A hypothesis to explain the role of such SS phase was then formulated based on the Brønsted acidity of OH groups of the solid framework. Overall, the AF catalyst allowed not only a straightforward upgrading of CG to acetals, but also a more cost-efficient protocol avoiding the expensive refining of raw glycerol itself.
[Mh] Termos MeSH primário: Acetais/síntese química
Compostos de Alumínio/química
Fluoretos/química
Glicerol/química
[Mh] Termos MeSH secundário: Acetais/química
Acetona/química
Biocombustíveis
Butanonas/química
Catálise
Temperatura Alta
Pressão
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Aluminum Compounds); 0 (Biofuels); 0 (Butanones); 1364PS73AF (Acetone); 6PT9KLV9IO (methylethyl ketone); PDC6A3C0OX (Glycerol); Q80VPU408O (Fluorides); Z77H3IKW94 (aluminum fluoride)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170417
[Lr] Data última revisão:
170417
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160524
[St] Status:MEDLINE


  9 / 1018 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27150898
[Au] Autor:Macura-Karbownik A; Chladek G; Zmudzki J; Kasperski J
[Ad] Endereço:Chair of Prosthetics and Dental Materials, Department of Dental Prosthetics, Medical University of Silesia in Katowice, School of Medicine with the Division of Dentistry in Zabrze, Zabrze, Poland.
[Ti] Título:Chewing efficiency and occlusal forces in PMMA, acetal and polyamide removable partial denture wearers.
[So] Source:Acta Bioeng Biomech;18(1):137-44, 2016.
[Is] ISSN:1509-409X
[Cp] País de publicação:Poland
[La] Idioma:eng
[Ab] Resumo:PURPOSE: Thermoplastic materials, such as acetal (AC) and polyamide (PA), constitute an alternative to polymethyl methacrylate (PMMA) based resins as the materials for removable partial dentures. However, none of the previous studies compared chewing efficiency and occlusal forces in the wearers of dentures made of various materials. Therefore, the aim of this study was to determine and compare the chewing efficiency and occlusal forces in PMMA, PA and AC RPDs' wearers. The hypothesis was that the type of denture base material shows a significant effect on chewing efficiency (expressed as a degree of food fragmentation) and occlusal force. METHODS: The experiment included the group of 30 patients using removable partial dentures. The dentures made of PMMA, acetal and polyamide were tested in each patient. Each denture was worn for 90 days, with a random sequence of the denture manufacturing and insertion. After 7, 30 and 90 days of each denture wear, chewing efficiency coefficient was determined with the aid of a sieving method, and occlusal force was measured with a dynamometer. RESULTS: The use of dentures made of PMMA or acetal was reflected by a marked increase in chewing efficiency and occlusal force. None of these parameters changed significantly with the time of denture wear. Moreover, no significant correlation was found between chewing efficiency and occlusal forces. CONCLUSIONS: Denture base material exerts significant effects on the degree of food fragmentation and the level of occlusal forces. The use of dentures and clasps made of materials with lower modulus of elasticity is associated with lower chewing efficiency and lower occlusal forces.
[Mh] Termos MeSH primário: Acetais/farmacologia
Força de Mordida
Prótese Parcial Removível
Mastigação/efeitos dos fármacos
Nylons/farmacologia
Polimetil Metacrilato/farmacologia
[Mh] Termos MeSH secundário: Adulto
Feminino
Seres Humanos
Masculino
Meia-Idade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Nylons); 9011-14-7 (Polymethyl Methacrylate)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170113
[Lr] Data última revisão:
170113
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160507
[St] Status:MEDLINE


  10 / 1018 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27085740
[Au] Autor:Huang M; Furukawa T; Retailleau P; Crich D; Bohé L
[Ad] Endereço:Institut de Chimie des Substances Naturelles, CNRS-ICSN UPR2301, Université Paris-Sud, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
[Ti] Título:Further studies on cation clock reactions in glycosylation: observation of a configuration specific intramolecular sulfenyl transfer and isolation and characterization of a tricyclic acetal.
[So] Source:Carbohydr Res;427:21-8, 2016 Jun 02.
[Is] ISSN:1873-426X
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The use of the 2-O-(2-trimethylsilylmethallyl) group as intramolecular nucleophile and cation clock reaction in the glucopyranose series depends on the nature of the glycosyl donor. As previously reported, with trichloroacetimidates the anticipated intramolecular Sakurai reaction proceeds efficiently and is an effective clock, whereas with sulfoxides complications arise. The source of these complications is now shown to be an intramolecular sulfenyl transfer reaction between the tethered allylsilane and the activated sulfoxide. These results illustrate how a different unimolecular clock reaction may be required for a given cation when it is generated from different donors in order to avoid side reactions. The synthesis and cyclization of a 2-O-(3-hydroxypropyl) glucopyranosyl sulfoxide leading on activation to the formation of a trans-fused acetal is also described. The formation of this crystallographically-established trans-fused acetal is discussed in terms of the high effective concentration of the intramolecular nucleophile which leads to a high degree of a SN2 character in the displacement of the α-glucosyl triflate or at the level of the corresponding α-CIP. The possible use of such intramolecular alcohols as clock reactions and their limitations is discussed.
[Mh] Termos MeSH primário: Acetais/síntese química
Sulfóxidos/química
[Mh] Termos MeSH secundário: Acetais/química
Configuração de Carboidratos
Cátions/química
Cristalografia por Raios X
Ciclização
Glicosilação
Modelos Moleculares
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetals); 0 (Cations); 0 (Sulfoxides)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170602
[Lr] Data última revisão:
170602
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160418
[St] Status:MEDLINE



página 1 de 102 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