Search
Now showing items 31-40 of 895
A comparative analysis of the chemical nature of defensive secretions of Gonyleptidae (Arachnida : Opiliones : Laniatores)
(Biochemical Systematics and Ecology, 2005-12-01) [Artigo]
The arachnids of the order Opiliones (harvestmen) produce substances used in defense. In the present paper, we analyzed 22 species of Gonyleptidae to explore the use of defensive substances in taxonomy and evolutionary ...
Aromatic compounds from three Brazilian Lauraceae species
(Química Nova, 2010-01-01) [Artigo]
Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of São Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees & Mart. ex Nees resulted in the isolation ...
Antifungal activity of flavonoids from Heteropterys byrsonimifolia and a commercial source against Aspergillus ochraceus: In silico interactions of these compounds with a protein kinase
(Crop Protection, 2014-08-01) [Artigo]
To contribute to the development of new methods to reduce the contamination of coffee beans with Aspergillus ochraceus and ochratoxin A, a toxin produced by this fungus, the present work initially aimed to select plant ...
Antifungal amides from Piper hispidum and Piper tuberculatum
(Phytochemistry, 2000-11-01) [Artigo]
Piper hispidum and Piper tuberculatum accumulate amides bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties. The isolation and characterization of several representatives including two hitherto unreported ...
Improvement of Pro-Oxidant Capacity of Protocatechuic Acid by Esterification
(Plos One, 2014-10-23) [Artigo]
Pro-oxidant effects of phenolic compounds are usually correlated to the one-electron redox potential of the phenoxyl radicals. Here we demonstrated that, besides their oxidizability, hydrophobicity can also be a decisive ...
Aspectos químicos, biológicos e etnofarmacológicos do gênero Cassia
(Química Nova, 2006-11-01) [Artigo]
Species of Cassia are widely distributed in tropical and subtropical regions throughout the world, and have been extensively investigated chemically and pharmacologically.They are known to be a rich source of phenolic ...
Breve revisão de métodos de determinação de resíduos do herbicida á cido 2,4-diclorofenoxiacético (2,4-D)
(Química Nova, 2003-03-01) [Artigo]
This paper supplies a revision about the main techniques of extraction, clean-up and pre-concentration of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water and soil samples, as well as chromatographic methods ...
Antimalarial activity of piperidine alkaloids from Senna spectabilis and semisynthetic derivatives
(Journal of the Brazilian Chemical Society, 2014-10-01) [Artigo]
In our continuing work looking for new anti-infective lead compounds from Brazilian biomes, the two known piperidine alkaloids ( - )-cassine and ( - )-spectaline were isolated from the flowers of Senna spectabilis (syn. ...
Continuous vs. segmented second-dimension system gradients for comprehensive two-dimensional liquid chromatography of sugarcane (Saccharum spp.)
(Analytical and Bioanalytical Chemistry, 2014-07-01) [Artigo]
A comprehensive two-dimensional liquid chromatography system in combination with photodiode array and mass spectrometry detection was developed for analysis of polyphenols in sugarcane (Saccharum spp.) leaf extracts. To ...
A simple and environmentally friendly reflectometric method for the rapid quantitative analysis of captopril in pharmaceutical formulations
(Eurasian Journal of Analytical Chemistry, 2011-12-01) [Artigo]
This paper describes a simple, environmentally friendly and rapid quantitative spot test procedure for the determination of captopril (CPT) in bulk drug and in pharmaceutical formulations by using diffuse reflectance ...