753 resultados para Chlorinated Alkaloids


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Includes bibliographical references.

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Mode of access: Internet.

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"Project 16030 ELZ; Program element 1BA027."

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Three new alkaloids, the two pyrrolidine type alkaloids (1 and 2) and 6E-pandanamine (3), together with five known alkaloids (4-8), were isolated from the leaves of Pandanus amaryllifolius collected in West Java, Indonesia. All the new alkaloids have two alpha-methyl alpha,beta-unsaturated gamma-lactone moieties, while compound 2 also has an additional seven-membered ring, which has not been encountered before in Pandanus alkaloids. Two different extraction methods, namely, a solvent partitioning extraction and acid-base treatment, were tested, giving secondary and tertiary amines, respectively. Spectroscopic and chemical studies showed that the tertiary amines isolated from the acid-base treatment were artifacts formed during the extraction process. This finding suggests that the use of conventional acid-base treatment in isolating Pandanus alkaloids should be reviewed since it can introduce artifacts.

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A new indole alkaloid, akuammiginone (1), and a new glycosidic indole alkaloid, echitamidine-N-oxide 19-O-beta-D-glucopyranoside (2), together with the five known alkaloids, echitaminic acid (3), echitamidine N-oxide (4), N-b-demethylalstogustine N-oxide (5), akuammicine N-oxide (6), and N-b-demethylalstogustine (7), were isolated from the trunk bark of Alstonia scholaris collected in Timor, Indonesia. The structures of all compounds were elucidated by spectroscopic methods. This is the first report of compounds 3-5 and 7 in A. scholaris. Some NMR assignments of the known compounds were revised.

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Two new indole alkaloids, polyneuridine-N-oxide (1) and 17-hydroxy-10-methoxy-yohimbane (2), together with seven known alkaloids were isolated from the roots of Ochrosia acuminata collected in Savu, Indonesia. 9-Methoxyellipticine (3) and ellipticine (4) were responsible for the antitumor activities of the extract. The structures of all compounds were elucidated using MS and NMR methods.

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Rapid access to the ABCE ring system of the C-20 diterpene alkaloids was achieved by silver (I) promoted intramolecular Friedel-Crafts arylation of a functional group specific 5-bromo-3-azabicyclo[3.3.1]nonane derivative. (c) 2005 Elsevier Ltd. All rights reserved.

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The alkaloid content of Senecio madagascariensis collected from Australia and Hawaii was examined. Alkaloids were identified from the above ground whole plant (stems, leaves and flowers) by GUMS analysis and included: senecivernine, senecionine, integerrimine, senkirkine, mucronatinine, retrosine, usaramine, otosenine, acetylsenkirkine, desacetyldoronine, florosenine and doronine. Plant material collected from the Hawaiian Islands was found to be identical in pyrrolizidine alkaloid content to that from a single composite collection made from northern New South Wales, Australia. Overall, no appreciable differences in alkaloid content were found between locations, whereas variation among individual plants was evident. The average total pyrrolizidine alkaloid content varied from a low of 217 mu g/g to a high of 1990 mu g/g (dry weight basis) among the locations. Based on comparable alkaloid content and documented pyrrolizidine alkaloidosis cases from Australia, S. madagascariensis may pose a significant risk to livestock grazing heavily infested ranges on the Hawaiian Islands. (c) 2006 Elsevier Ltd. All rights reserved.

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Cylindrospermopsin (CYN), a potent cyanobacterial hepatotoxin produced by Cylindrospermopsis raciborskii and other cyanobacteria, is regularly found in water supplies in many parts of the world and has been associated with the intoxication of humans and livestock.Water treatment via chlorination can degrade the toxin effectively but result in the production of several byproducts. In this study, male and female Balb/c mice were injected via the intraperitoneal (IP) route with a single dose of 10 mg/kg 5-chlorouracil and 10 mg/kg 5-chloro-6-hydroxymethyluracil; these two compounds are the predicted chlorinated degradation products of CYN.DNA was isolated from the mouse livers and examined for strand breakage by alkaline gel electrophoresis (pH 12). The median molecular length (MML) of the DNA distributed in the gel was determined by estimating the midpoint of the DNA size distribution by densitometry. The toxicity of 5-chlorouracil (as measured by DNA strand breakage) was significantly influenced by time from dosing. There was no significant difference in MML between mice dosed with 5-chloro-6-hydroxymethyluracil and the controls. In another experiment, mice were dosed with 0, 0.1, 1, 10 and 100 mg/kg body weight 5-chlorouracil and 0, 0.1, 1, 10 and 20 mg/kg 5-chloro-6-hydroxymethyluracil via IP injection. The heart, liver, kidney, lung and spleen were removed, fixed and examined under electron microscopy. Liver was the main target organ. The EM results revealed marked distortion on the nuclear membrane of liver cells in mice dosed with 1.0 mg/kg 5-chlorouracil or 10 mg/kg 5-chloro-6-hydroxymethyluracil, or higher.