13 rezultatima
Investigation of the aerial parts of Schizanthus tricolor yielded seven isomeric tropane alkaloids: 3alpha-(1-methylitaconyl)-6beta-senecioyloxytropane (1), 3alpha-(1-methylitaconyl)-6beta-angeloyloxytropane (2), 3alpha-(1-methylmesaconyl)-6beta-senecioyloxytropane (3),
Three tropane alkaloids, named schizanthines N, O, and P (1-3), have been isolated from the crude alkaloid extract of the endemic Chilean plant Schizanthus tricolor. On the basis of extensive NMR studies and MS fragmentation analysis, their structures were determined to be
The relative lack of specificity of atropine as a competitive antagonist of muscarinic receptors is a frequent cause of undesirable parasympathetic side effects. Consequently, new tropane alkaloids with potentially greater selectivity are usually seen with real interest. The cholinergic antagonistic
Two new hygroline and tropane alkaloids, 4-hydroxybenzenepropanoylhygroline (1) and 3α,4β-dihydroxy-6β-angeloyoxytropane (2) have been isolated from the aerial parts of Schizanthus hookeri and S. tricolor, respectively, two plants indigenous from Chile. Their structures were elucidated by
A rapid in vitro propagation system leading to formation of shoots from callus, roots, and plantlets was developed for Schizanthus hookeri Gill. (Solanaceae), an endemic Chilean plant. The genus Schizanthus is of particular interest due to the presence of several tropane alkaloids. So far, in vitro
This study presents a very fast GC analysis applied for the baseline separation of isomeric tropane alkaloids extracted from the stem-bark of Schizanthus grahamii (Solanaceae). The work provided a challenging application where isothermal analysis in conjunction with very short narrow bore columns (3
Schizanthus grahamii is an endemic Chilean plant that is known to contain tropane alkaloids. Five new alkaloids, grahamines A-E (1-5), were isolated and characterized by extensive spectroscopic analysis. Their structures were determined to be
The potential of non-aqueous capillary electrophoresis was investigated for the separation of four isomeric tropane alkaloids, namely 3alpha-senecioyloxy-7beta-hydroxytropane, 3alpha-hydroxy-7beta-senecioyloxytropane, 3alpha-hydroxy-7beta-angeloyloxytropane and 3alpha-hydroxy-7beta-tigloyloxytropane
Two fully automated HPLC-NMR methods are reported and compared for the structure elucidation of four isomeric tropane alkaloids from the stem-bark of an endemic Chilean plant, Schizanthus grahamii Gill. (Solanaceae). The first approach interfaced a conventional HPLC column to NMR by means of a loop
This study presents the outstanding chromatographic selectivity of a porous graphitic carbon support for the separation of four isomeric tropane alkaloids from the stem-bark of Schizanthus grahamii (Solanaceae). Capillary liquid chromatography coupled to mass spectrometry was studied after the
A purified stem bark extract from Schizanthus grahamii was analyzed by combining capillary gas chromatography with a selective nitrogen phosphorus detector, mass spectrometry and Fourier transform infrared spectroscopy. Several positional and configurational tropane isomers were detected and their
The strict application of IUPAC rules for the numbering of tropane alkaloids is not always applied by authors and there is hence a lot of confusion in the literature. In most cases, the notation of 3, 6/7-disubstituted derivatives has been chosen arbitrarily, based on NMR and MS data, without taking
The absolute configuration (AC) of 6beta-hydroxy-3alpha-senecioyloxytropane (1), 3alpha-hydroxy-6beta-tigloyloxytropane (2), 3alpha-hydroxy-6beta-senecioyloxytropane (3), and 3alpha-hydroxy-6beta-angeloyloxytropane (4) was assigned as (1R,3R,5S,6R) using density functional theory (DFT) calculations