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Quinolizidine Alkaloids (quinolizidine + alkaloid)

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Chemistry100%

Selected Abstracts

Synthesis of the Quinolizidine Alkaloids (-)-Lasubine II (I) and (.+-.)-Myrtine (II) by Conjugate Addition and Intramolecular Acylation of Amino Esters with Acetylenic Sulfones.

CHEMINFORM, Issue 26 2005
Thomas G. Back
No abstract is available for this article. [source]

ALKALOID COMPOSITION OF LUPINUS CAMPESTRIS FROM MEXICO

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2001
J. MARTÍNEZ-HERRERA
ABSTRACT The content of quinolizidine alkaloids (QA) in Lupinus campestris, Fabaceae family, was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS), Samples of various organs of Lupinus campestris collected at different monthly stages of the growing plant, were subjected to extraction in a Merck Extrelut column. The quinolizidine alkaloid patterns of stems, leaves, flowers, pods and seeds were assessed and then identified and quantified by GC. Alkaloid structures were identified according to their mass fragmentation patterns, in combination with their indicative Kovats retention index. Alkaloids found in several developmental stages of the plant were mainly: aphyllidine, 5, 6-dehydrolupanine, aphylline, dehydro-oxosparteine, lupanine, ,-isolupanine, hydroxyaphylline and hydroxyaphyllidine, plus two alkaloids that -were not identified. During the third month the relative abundance of total alkaloids were highest. The main alkaloids found in seeds were hydroxyaphylline and hydroxyaphyllidine. [source]

NMR study of quinolizidine alkaloids: relative configurations, conformations,

MAGNETIC RESONANCE IN CHEMISTRY, Issue 4 2005
Phuong Mai Le
Abstract Extracts of fruits and leaves of Connarus paniculatus afford six quinolizidine alkaloids which were identified as piptanthine, 18-epipiptanthine, ormosanine, homoormosanine, podopetaline (monohydrochloride) and homopodopetaline on the basis of high-field NMR studies. 1D and 2D NMR experiments provide complete assignments of the 1H and 13C spectra. In conjunction with detection of nuclear Overhauser effects (NOESY), these results allow detailed structure characterization including determination of relative configurations for the chiral sites and conformational analysis. Exchange phenomena involving nitrogen inversion were detected. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Determination of quinolizidine alkaloids in Sophora tonkinensis by HPCE

PHYTOCHEMICAL ANALYSIS, Issue 4 2005
Pei-lan Ding
Abstract A simple, rapid and reliable high-performance capillary electrophoresis method has been developed to determine quantitatively the alkaloid content of Sophora tonkinensis, a Chinese herb commonly known as shan-dou-gen. A total of seven quinolizidine alkaloids (cytisine, sophocarpine, matrine, lehmannine, sophoranol, oxymatrine and oxysophocarpine) could be readily separated within 15 min. The running buffer was 50 mM phosphate buffer (pH 2.5) containing 1% hydroxypropyl- , -cyclodextrin and 3.3% isopropanol in water. The applied voltage was 25 kV, the capillary temperature was 25°C, the detection wavelength was 200 nm and scopolamine butylbromide was used as internal standard. The method was used to analyse the chemical constituents of two commercial alternatives to shan-dou-gen. The alkaloid constituents of authentic shan-dou-gen gave a specific HPCE electropherogram that could be used to distinguish the drug from potential substitutes. Furthermore, the content of oxymatrine and the total content of the seven quinolizidine alkaloids could be used as quantitative markers in order to assess the quality of S. tonkinensis. Copyright © 2005 John Wiley & Sons, Ltd. [source]