Recent work showed that 4-{A/-methyl-A/-nitrosamino)-1-(3pyridyl)-1-butanone (NNK) was present in some cured tobacco and was more carcinogenic than N'-nitrosonornicotine (NNN). In the present investigation, the concentration relationships of NNK, NNN, and their probable precursors, i.e., nitrite, nitrate, and alkaloids, were determined: (a) after the growth of Ky 14 burley tobacco under differe...

Pilocarpus microphyllus Stapf ex Wardleworth (jaborandi, Rutaceae) is one of the most important Brazilian medicinal species owing to its content of pilocarpine (PIL), an alkaloid used for treating glaucoma and xerostomia. This species contains another alkaloid, epiisopiloturine (EPI), which has demonstrated effectiveness against schistosomiasis. The aim of this work was to assess seasonal chang...

A controlled feeding study was undertaken to determine the physiological and production effects of consuming perennial ryegrass alkaloids (fed via seed) under extreme heat in sheep. Twenty-four Merino ewe weaners (6 months; initial BW 30.8 ± 1.0 kg) were selected and the treatment period lasted 21 days following a 14 day acclimatisation period. Two levels of two factors were used. The first fac...

Poison frogs contain an alkaloid-based chemical defense that is sequestered directly from a diet of alkaloid-containing arthropods. Geographic and temporal variation in alkaloid defense is common in poison frogs and is generally attributed to differences in the availability of alkaloid-containing arthropods. Variable chemical defense in poison frogs may have important consequences for predator-...

Cissampelos capensis, commonly known by the Afrikaans name "dawidjies" or "dawidjieswortel", is the most important and best known medicinal plant of the family Menispermaceae used by the Khoisan and other rural people in the western region of South Africa. The main alkaloids in the leaves, stems and rhizomes were isolated and identified. Several of the main compounds were previously found in sp...

Antimicrotubule Vinca alkaloids, such as vinblastine and vincristine, interfere with the dynamics of microtubules and have shown significant cell killing activity in a variety of tumor cells through induction of apoptosis. The mechanism by which Vinca alkaloids induce apoptosis is not entirely clear. In this study, we found that glucocorticoids inhibit Vinca alkaloid-induced apoptosis without a...

Studies on the antioxidant and antimicrobial activities of Mitragyna speciosa leaf extracts are lacking. In this study the antioxidant properties of water, methanolic and alkaloid M. speciosa leaf extracts were evaluated using the DPPH (2,2-diphenyl-1- picrylhydrazyl) radical scavenging method. The amount of total phenolics and flavanoid contents were also estimated. The DPPH IC(50) values of t...

OBJECTIVES Evaluation of the Sophora alopecuroides var. alopecuroides seed effects on morphine withdrawal syndrome in mice and determination of the alkaloid composition of the seed total extract. MATERIALS AND METHODS The effects of the seed total extract, alkaloid fraction and major compound matrine on the mice morphine withdrawal syndrome were compared to saline and methadone. Mice were mad...

Low larkspurs (Delphinium nuttalliunum Pritz., Delphinium andersonii Gray) and plains larkspur (Delphinium geyeri Greene) often poison cattle grazing on western North American rangelands. The dominant toxic alkaloid in larkspur is methyllycaconitine (MLA); other very toxic alkaloids in low and plains larkspurs are nudicauline and geyerline. Toxic alkaloid concentrations in larkspur near or abov...