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Helivypolide G. A novel dimeric bioactive sesquiterpene lactone
(2004-08-23)
Helivypolide G was isolated from leaves of Helianthus annuus L. cv. Stella. In the course of our ongoing research for new allelochemicals from Helianthus annuus, a novel dimeric bioactive sesquiterpene lactone, helivypolide ...
Cromatografia em contra-corrente de gotejamento na separação de substâncias fenólicas de Neuropogon aurantiaco-ater
(2001-12-01)
This work reports the separation of phenolic compounds present in the metabolic extract of the lichen Neuropogon aurantiaco-ater (Usniaceae). The crude extract was fractionated by droplet counter-current chromatography ...
Interaction of local anesthetics with a peptide encompassing the IV/S4-S5 linker of the Na+ channel
(Elsevier B.V., 2006-08-20)
The peptide pIV/S4-S5 encompasses the cytoplasmic linker between helices S4-S5 in domain IV of the voltage-gated Na+ channel, residues 1644-1664. (2)The interaction of two local anesthetics (LA), lidocaine and benzocaine, ...
Lactate detection by MRS in mitochondrial encephalopathy: Optimization of technical parameters
(Blackwell Publishing, 2008-01-01)
Mitochondriopathies are a heterogeneous group of diseases with variable phenotypic presentation, which can range from subclinical to lethal forms. They are related either to DNA mutations or nuclear-encoded mitochondrial ...
Preconcentration and determination of metal ions from fuel ethanol with a new 2,2'-dipyridylamine bonded silica
(2013-02-01)
A silica surface chemically modified with [3-(2,2'-dipyridylamine) propyl] groups was prepared, characterized, and evaluated for its metal ion preconcentration in fuel ethanol. To our knowledge, we are the first authors ...
Study of adsorption and preconcentration by using a new silica organomodified with [3-(2,2′-dipyridylamine)propyl] groups
(2013-02-01)
In this work, a silica surface chemically modified with [3-(2,2′-dipyridylamine)propyl] groups, named [3-(2,2′- dipyridylamine)propyl]silica (Si-Pr-DPA) was prepared, characterized, and evaluated for its heavy metal ...
Screening Brazilian commercial gasoline quality by hydrogen nuclear magnetic resonance spectroscopic fingerprintings and pattern-recognition multivariate chemometric analysis
(Elsevier B.V., 2010-06-30)
The identification of gasoline adulteration by organic solvents is not an easy task, because compounds that constitute the solvents are already in gasoline composition. In this work, the combination of Hydrogen Nuclear ...
Analysis of the molecular association of rifampicin with hydroxypropyl-²-cyclodextrin
(Divisão de Biblioteca e Documentação do Conjunto das Químicas da Universidade de São Paulo, 2004-03-01)
Foram preparados complexos de inclusão de rifampicina (RP) com hidroxipropil-²-ciclodextrina (HP²CD). A solubilidade da RP em água aumentou linearmente com a concentração de ciclodextrina na faixa de concentração utilizada ...
Identificação de diterpenos clerodânicos em diferentes órgãos de Casearia sylvestris Swartz
(2009-09-01)
Casearia sylvestris Swartz (Salicaceae) is a tree or shrub distributed widely in Brazil, where it is used in popular medicine. Several bioactive clerodane diterpenes typical of Casearia have been isolated from this species ...