Strychnin

DescriptionStrychnine, C21H22N2O2, Mr 334.4, mp 270–280 C (decomp.), forms colorless crystals which are slightly soluble in water, moderately in benzene, ethanol, readily soluble in chloroform [9, p. 1121].

HistoryStrychnine is a white, odorless, toxic crystalline powder with a bitter taste. Strychnine is a well-known poison, but it has also been used in medications. It was one of the first alkaloids to be isolated in pure form when Joseph Bienaimé Caventou (1795 1877) and Pierre Joseph Pelletier (1788 1842) extracted it from Saint Ignatius beans (Strychnos ignatii) in 1818. Caventou and Pelletier subsequently obtained it from its main source Strychnos nux vomica; it is also found in other Strychnos species. Strychnos nux vomica is an evergreen tree native to east India, Southeast Asia, and northern Australia. The seeds of the plant are the main source of strychnine and several other alkaloids (brucine), but it is also obtained from the bark and roots. The seeds are heated and then ground to a powder that contains strychnine. The brownish-gray powder obtained from the ground seeds extracted from the nut is called nux vomica. In commercial production during the 1800s, the seeds were softened by boiling in a dilute sulfuric acid solution and then dried and ground to a powder. Strychnine was extracted from the powder using alcohol and separation techniques to remove impurities. The structure of strychnine was determined by Robert Robinson (1886 1975) in 1946; the next year Robinson received the Nobel Prize in chemistry for his work on alkaloids. Robert Burns Woodward (1917 1979) performed the first complete synthesis of strychnine in 1953.Strychnine was used in its impure powder form centuries before it was isolated. The nuts that yielded the seeds were given names such as poison nut or vomit nuts. Early workers on its properties warned about its poisonous properties and recommended against it internal use.

UsesStrychnine as nux vomica was available in apothecaries throughoutthe 19th century, and strychnine salts such as strychnine sulfate, strychnine nitrate, andstrychnine phosphate were a popular medicine. It was sold as pills, powders, and tinctures.Small quantities of strychnine were added to tonics to serve as stimulants. Because its bittertaste stimulates saliva and gastric production, strychnine was used to counteract the lossof appetite produced by various diseases. Hypodermic injections of strychnine along withdigitalis were prescribed for treating acute heart failure in the early 20th century. Otherconditions for which strychnine was prescribed included paralysis, impotence, alcoholism,and drug addiction.Today strychnine as nux vomica is still available as an herbal ingredient for herbal and homeopathic remedies. The action of nux vomica is attributed to strychnine and brucine. It is recommended for stomach ailments such as atonic dyspepsia, constipation, heart burn, and indigestion. It is reported to relieve nausea during pregnancy. Chinese herbalists use nux vomica externally to treat tumors, headaches, and paralysis. It is recommended for the treatment of Bell's palsy. Strychnine has some uses in modern traditional medicine. It has been used to treat the genetic disorder nonketotic hyperglycinaemia (NKH). NKH is related to glycine metabolism; it can lead to high levels of the inhibitory receptor glycine resulting in seizures. Strychnine is used in neurological research by applying it to areas of the brain or spinal column and observing how the nervous system responds. This method is called strychnine neuronography. Strychnine has been used in conjunction with antivenoms to treat poisonous snake bites. Strychnine is sometimes cut into cocaine, heroin, and other illegal substances in the production of designer drugs. Strychnine was once used liberally as a pesticide, especially to control vertebrates.It is used as a salt in granular bait formulations. In the United States its use has been progressively limited over the years. . In the1980s, its use was curtailed for above-ground applications to reduce toxicity to nontargetspecies, especially birds; by the end of the decade, its use was limited to below ground.Currently, strychnine is only registered for use by the EPA as a below-ground bait pesticidefor use on pocket gophers.