Strychnine alkaloids

Alkaloid substances derived from the seeds and bark of plants of the genus Strychnos (family Loganiaceae). This genus serves as the source of poisonous, nitrogen-containing plant materials, such as strychnine (see structure; R&dbnd;H). The seeds of the Asian species of Strychnos contain 2–3% alkaloids, of which about

half is strychnine and the rest is closely related materials; for example, brucine (see structure; R&dbnd;OCH₃) is a more highly oxygenated relative. Strychnine and brucine are isolated by extraction of basified plant residue with chloroform and then, from the chloroform solution, by dilute sulfuric acid. Precipitation from the dilute acid is accomplished with ammonium hydroxide. Strychnine is separated from brucine by fractional crystallization from ethanol. See also Crystallization.

At one time strychnine was used as a tonic and a central nervous system stimulant, but because of its high toxicity (5 mg/kg is a lethal dose in the rat) and the availability of more effective substances, it no longer has a place in human medicine.

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