Now showing items 1-10 of 77
Relações lineares múltiplas entre deslocamentos químicos em RMN 13C de haletos alifáticos
(Eclética Química, 1999-01-01) [Artigo]
Os deslocamentos químicos de RMN 13C de carbonos a , b , g e d de 17 conjuntos de haletos (F, Cl Br e I) alifáticos, inclusive compostos mono, bi e tricíclicos, podem ser reproduzidos por uma equação linear de duas constantes ...
Jatrowedione, a lathyrane diterpene from Jatropha weddelliana
(Phytochemistry, 1998-08-01) [Artigo]
3-Acetylaleuritolic acid, sitosterol and a novel lathyrane diterpene, jatrowedione, have been isolated from the roots of Jatropha weddelliana. The elucidation of the structure of the latter was accomplished by detailed NMR ...
Antifungal iridoids from the stems of Tocoyena formosa
(Journal of the Brazilian Chemical Society, 1996-07-01) [Artigo]
A new antifungal iridoid compound, together with three active known iridoids, galioside, galioside aglucone, and apodanthoside, as well as 3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl quinovic acid and quercetin- ...
Separation of flavonoids and naphthopyrones from four Brazilian Paepalanthus species by droplet countercurrent chromatography
(Revista Brasileira de Plantas Medicinais, 1999-12-01) [Artigo]
A general procedure was developed for the simultaneous separation of flavonoids and naphthopyrones from the polar extracts of the capitula from Brazilian everlasting plants is described. The ethanolic extracts of several ...
Gas Chromatographic Determination of Cyprodinil, Fludioxonil, Pyrimethanil, and Tebuconazole in Grapes, Must, and Wine
(Journal of AOAC International, 1997-07-01) [Artigo]
A rapid and simple gas chromatographic method for determinating cyprodinil, fludioxonil, pyrimethanil, and tebuconazole in grapes, must, and wine is described. An on-line microextraction method was used with a one-step ...
Determination and persistence of methiocarb in artichokes
(Italian Journal of Food Science, 1996-12-01) [Artigo]
A simple and rapid method for the determination of methiocarb in artichokes by high-performance liquid chromatography with UV detection is described. No derivatization is needed and the limit of determination (0.01 ppm) ...
Terpenes from Aristolochia triangularis
(Phytochemistry, 1990-12-01) [Artigo]
Phytochemical examination of Aristolochia triangularis led to the isolation of allantoin, nerolidol, sitosterol, dibenzylbutyrolactone type lignans and ent-kaurane type diterpenes. This is the first report on the isolation ...
8-benzylberbine alkaloids from Aristolochia gigantea
(Phytochemistry, 1992-12-01) [Artigo]
Phytochemical examination of Aristolochia gigantea led to the isolation of 10 alkaloids, belonging to the new 8-benzylberbine type. Eight of them occurred as glucosides. The structural assignments were based on analysis ...
Caffeic acid esters and triterpenes of Alibertia macrophylla
(Phytochemistry, 1991-12-01) [Artigo]
A hydroalcoholic extract of the leaves of Alibertia macrophylla afforded the esters of caffeic acid and 2-phenylethanol or 2-methyl butane-1,4-diol. The leaves also contain caffeic acid. The acetone extract of the stems ...
DDT and HCH residues in the blood serum of malaria control sprayers
(Bulletin of Environmental Contamination and Toxicology, 1996-11-01) [Artigo]