Sierra Larkspur

Description

Delphinium glaucum, known by the common names Sierra larkspur, mountain larkspur, and glaucous larkspur, is a species of wildflower in the genus Delphinium, which belongs to the buttercup family, Ranunculaceae. It is native to western North America from Arizona to Alaska, growing in moist mountainous environments such as riverbanks and meadows. The earliest phytochemical research on D.glaucum (then known as D. brownii ) was that of Richard Manske, working at the National Research Laboratories in Ottawa, Canada, in 1938, who isolated an alkaloid that he was unable to purify adequately, and the common plant-sugar, mannitol. A few years later, John Goodson, at the Wellcome Chemical Research Laboratories in London, England, isolated what he believed to be the same alkaloid, in purer form, from seeds of Delphinium elatum, and named it "methyl-lycaconitine". Further work to identify the chemical constituents of D. glaucum (still called D. brownii) was carried out by Michael Benn and his co-workers at the National Research Council laboratories in Ottawa, Canada in 1963. These chemists confirmed the presence of methyllycaconitine in the plant, and also isolated another, structurally related diterpenoid alkaloid, which they named browniine. Delphinium glaucum (still under the name D. brownii) was studied again by Mike Benn's research group, at the University of Calgary, in Canada, with the objective of identifying the compounds responsible for its toxicity. These researchers again found methyllycaconitine and browniine in the plant, but also a closely related alkaloid, browniine-14-acetate, as well as the alkaloid magnoflorine, belonging to the aporphine class. Of these, methyllycaconitine was found to be the most toxic.