Strychnine is a highly toxic, colorless, bitter, crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine, when inhaled, swallowed, or absorbed through the eyes or mouth, causes poisoning which results in muscular convulsions and eventually death through asphyxia. While it has no known medicinal effects, in the past the convulsant effect was believed to be beneficial in small doses. The most common source is from the seeds of the Strychnos nux-vomica tree.
Strychnos nux-vomica, the strychnine tree, also known as nux vomica, poison nut, semen strychnos, and quaker buttons, is a deciduous tree native to India and to southeast Asia. It is a medium-sized tree in the family Loganiaceae that grows in open habitats. Its leaves are ovate and 2–3.5 inches (5.1–8.9 cm) in size.
The Loganiaceae are a family of flowering plants classified in order Gentianales. The family includes up to 13 genera, distributed around the world's tropics. There are not any great morphological characteristics to distinguish these taxa from others in the order Gentianales.
Strychnos is a genus of flowering plants, belonging to the family Loganiaceae. The genus includes about 100 accepted species of trees and lianas, and more than 200 that are as yet unresolved. The genus is widely distributed around the world's tropics and is noted for the presence of poisonous indole alkaloids in the roots, stems and leaves of various species. Among these alkaloids are the well-known and virulent poisons strychnine and curare.
Curare is a common name for various plant extract alkaloid arrow poisons originating from indigenous peoples in Central and South America. Used as a paralyzing agent for hunting and for therapeutic purposes, Curare only becomes active by a direct wound contamination by a poison dart or arrow or via injection. These poisons function by competitively and reversibly inhibiting the nicotinic acetylcholine receptor (nAChR), which is a subtype of acetylcholine receptor found at the neuromuscular junction. This causes weakness of the skeletal muscles and, when administered in a sufficient dose, eventual death by asphyxiation due to paralysis of the diaphragm. Curare is prepared by boiling the bark of one of the dozens of plant alkaloid sources, leaving a dark, heavy paste that can be applied to arrow or dart heads. Historically, curare has been used as an effective treatment for tetanus or strychnine poisoning and as a paralyzing agent for surgical procedures.
Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups and are thus called terpene indole or secologanin tryptamine alkaloids. Containing more than 4100 known different compounds, it is one of the largest classes of alkaloids. Many of them possess significant physiological activity and some of them are used in medicine. The amino acid tryptophan is the biochemical precursor of indole alkaloids.
Alcuronium chloride is a neuromuscular blocking (NMB) agent, alternatively referred to as a skeletal muscle relaxant. It is a semi-synthetic substance prepared from C-toxiferine I, a bis-quaternary alkaloid obtained from Strychnos toxifera. C-toxiferine I itself has been tested for its pharmacological action and noted to be a very long acting neuromuscular blocking agent For a formal definition of the durations of actions associated with NMB agents, see page for gantacurium. The replacement of both the N-methyl groups with N-allyl moieties yielded N,N-diallyl-bis-nortoxiferine, now recognized as alcuronium.
Arrow poisons are used to poison arrow heads or darts for the purposes of hunting and warfare. They have been used by indigenous peoples worldwide and are still in use in areas of South America, Africa and Asia. Notable examples are the poisons secreted from the skin of the poison dart frog, and curare, a general term for a range of plant-derived arrow poisons used by the indigenous peoples of South America.
Strychnos spinosa, the Natal orange, is a tree indigenous to tropical and subtropical Africa. It produces, sweet-sour, yellow fruits, containing numerous hard brown seeds. Greenish-white flowers grow in dense heads at the ends of branches. The fruits tend to appear only after good rains. It is related to the deadly Strychnos nux-vomica, which contains strychnine. The smooth, hard fruit are large and green, ripen to yellow colour. Inside the fruit are tightly packed seeds, which may be toxic, surrounded by a fleshy, brown, edible covering. Animals such as baboon, monkeys, bushpig, nyala and eland eat the fruit. The leaves are a popular food source for browsers such as duiker, kudu, impala, steenbok, nyala and elephant.
Strychnos benthami is a species of plant in the Loganiaceae family. It is endemic to Sri Lanka.
Strychnos chromatoxylon is a species of plant in the Loganiaceae family. It is found in Cameroon, Central African Republic, and Ivory Coast.
Strychnos tetragona is a species of plant in the Loganiaceae family. It is endemic to Sri Lanka.
Strychnos ignatii is a tree in the Loganiaceae family, native to the Philippines, particularly in Catbalogan and parts of China. The plant was first described by the Moravian (Czech) Jesuit working in the Philippines, brother Georg Kamel who named its seeds "the beans of St. Ignatius", in honour of the founder of his religious order.
Toxiferine is a curare toxin. It is a bisindole alkaloid derived from Strychnos toxifera and a nicotinic acetylcholine receptor antagonist. This alkaloid is the main toxic component of Calabash curare, and one of the most toxic plant alkaloids known. The lethal dose (LD50) for mice has been determined as 10 - 60 µg/kg by intravenous administration. It is a muscle relaxant that causes paralysis of skeletal muscle, which takes approximately 2 hours to recovery for a moderate dose, and 8 hours of total paralysis with a 20-fold paralytic dose. The paralysis can be antagonized by Neostigmine
Strychnos madagascariensis, the black monkey orange, is an African tropical and sub-tropical tree belonging to the Loganiaceae family. It is a tree with characteristically large fruit but can confused with some other species of the genus.
Strychnos usambarensis is a shrub or small tree up to 15m tall or a 70m long liane of Sub-Saharan Africa, occurring in forest and woodland, mountain ravines and coastal bush, often on rocky slopes and named for the Usambara Mountains of Tanzania. The species is found from Guinea east to Nigeria, from Congo east to Kenya and south to kloofs of the Magaliesberg of South Africa. Bantu tribes from Rwanda and Tanzania produce an arrow poison from the root bark and leaves of this species, sometimes combining it with extracts from other plants.
Macusine B is an inhibitor of adrenergic alpha-receptors and tryptamine receptors.
Pieter Willem Leenhouts was a Dutch botanist. He worked at the Rijksherbarium from 1947 until his official retirement in 1991, and then was an honorary member of staff until 1999. He was editor of Blumea from 1973 to 1999.
Strychnos icaja is a species belonging to the plant family Loganiaceae, native to West Tropical Africa. It is a very large, tropical rainforest liana which may attain a length of 100 m (330 ft).
