OBJECTIVES To determine the relative quantities of two hepatotoxic pyrrolizidine alkaloids, symphytine and echimidine, in teas prepared from comfrey leaves (Symphytum officinale), and to determine the potential contribution of the N-oxide forms of these alkaloids to levels of the parent alkaloids. DESIGN Comfrey leaves were purchased from three commercial sources and used to prepare tea in a ...

Many hemiparasites, including several members of the Castilleja genus (Scrophulariaceae), obtain secondary compounds from their host plants. Both Castilleja miniata in subalpine Colorado and C. indivisa in central Texas have reduced herbivory when obtaining alkaloids from the hosts Lupinus argenteus and L. texensis (Fabaceae), respectively. However, pollinators were not deterred from visiting C...

Aconitum species accumulate highly toxic diterpene alkaloids, which have attracted considerable interest because of their complex structure, interesting chemistry and noteworthy physiological effects. The authors carried out phytochemical analysis of two Aconitum species native to the Carpathian Basin, aiming the isolation of diterpene alkaloids. The multistep chromatographic purification of th...

Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine. Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chromatographic methods. Herein, tandem mass spectrometry combined with liquid chromatography separation prov...

Allowable limits for cereal ergot alkaloids in livestock feeds are being re-examined, and the objective of this study was to compare nutrient digestibility, growth performance and carcass characteristics of ram lambs fed a range of alkaloid concentrations, including the maximum currently allowed in Canada (2 to 3 ppm). Four pelleted diets were fed: control, with no added alkaloids; 930; 1402; a...

On a preliminary screening, substantial leishmanicidal activity was observed for the petroleum ether and alkaloidal extracts of the stem bark of Unonopsis buchtienii, the alkaloids and sterols isolated from these were studied. Of the alkaloids, liriodenine exhibited the highest activity against Leishmania major and L donovani (IC100 = 3.12 micrograms/mL). On the other hand, O-methylmoschatoline...

Objectives: To determine the relative quantities of two hepatotoxic pyrrolizidine alkaloids, symphytine and echimidine, in teas prepared from comfrey leaves (Symphytum officinale), and to determine the potential contribution of the Noxide forms of these alkaloids to levels of the parent alkaloids. Design: Comfrey leaves were purchased from three commercial sources and used to prepare tea in a m...

A total of seventeen alkaloids, comprising six macroline (including alstofolinine A, a macroline indole incorporating a butyrolactone ring-E), two ajmaline, one sarpagine, and eight akuammiline alkaloids, were isolated from the stem-bark and leaf extracts of the Malayan Alstonia macrophylla. The structure and relative configurations of these alkaloids were established using NMR, MS and in sever...