Marcelo Sobral da Silva

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Many natural substances with proven anti-inflammatory activity have been isolated throughout the years. The aim of this review is to review naturally sourced alkaloids with anti-inflammatory effects reported from 2000 to 2010. The assays were conducted mostly in vivo, and carrageenan-induced pedal edema was the most used experimental model. Of the 49(More)
This review of the current literature aims to study correlations between the chemical structure and gastric anti-ulcer activity of tannins. Tannins are used in medicine primarily because of their astringent properties. These properties are due to the fact that tannins react with the tissue proteins with which they come into contact. In gastric ulcers, this(More)
Chemical studies of Praxelis clematidea R.M. King & Robinson resulted in the isolation of six flavones: Apigenine, genkwanine, 7,4'-dimethylapigenin, trimethylapigenin, cirsimaritin and tetramethylscutellarein, which were tested for their toxicity against Staphylococcus aureus SA-1199B, a strain possessing the NorA efflux pump. Efflux pumps are integral(More)
A novel alkaloid named bowdichine (1), only the third with a diaza-adamantane skeleton containing an unusual N-acetyl enamine moiety, and the known alkaloids acosmine (2), ormosanine (3) and podopetaline (4) have been isolated from the stem bark of Bowdichia virgilioides. The structures were elucidated on the basis of spectral data, mainly 1D and 2D NMR of(More)
Aplysina is the best representative genus of the family Aplysinidae. Halogenated substances are its main class of metabolites. These substances contribute greatly to the chemotaxonomy and characterization of the sponges belonging to this genus. Due to their pharmacological activities, these alkaloids are of special interest. The chemistry of halogenated(More)
Two new diterpenes of the ent-trachylobane type were isolated from the stems of Xylopia langsdorffiana, ent-7alpha-acetoxytrachyloban-18-oic acid (1) and ent-7alpha-hydroxytrachyloban-18-oic acid (2). The structures of these isolates were deduced by spectroscopic data interpretation. X-ray crystallography of 1 was used to confirm its structure. The(More)
Flavonoids are phenolic compounds, secondary metabolites of plants that cause several benefits to our health, including helping the treatment against cancer. These pharmacological properties are associated with the ability of flavonoids in attenuating the generation of reactive oxygen species, acting as chelate compounds or affecting the oxi-redox cycle. In(More)
Iridoids and ecdysteroids are found in some genera of the family Verbenaceae. In such cases, they are used as chemotaxonomic markers for the difficult task of taxonomic identification by using morphological characteristics of plants belonging to this family. The present work describes the distribution of ecdysteroids in plants from the genus Vitex from a(More)
The cardiovascular effects induced by labdane-302, a diterpene isolated from the stems of Xylopia langsdorffianna St. Hill and Tull, were evaluated in male Wistar rats. In normotensive, conscious animals, labdane-302 produced dose-dependent hypotension and tachycardia. These effects were significantly attenuated after pre-treatment with L-NAME (20 mg/kg,(More)
Erythroxylum, the most representative genus of the Erythroxylaceae family, presents tropane alkaloids as main constituents. This class of compounds greatly contributes to the chemotaxonomic characterization of plants of this genus, and it has important medical uses and shows toxic effects. This review describes 186 tropane alkaloids in the 35 species of(More)