Poisonous plants Hemlock, poison

Natural products that contain caibon-caibon triple bonds aie numerous. Two examples aie tariric acid, from the seed fat of a Guatemalan plant, and cicutoxin, a poisonous substance isolated from water hemlock. 

Even today, accidental human poisonings occasionally occur however most current reports involve ingestion by livestock species. An incident of human poisoning was reported by Frank et al. (1995) in which a six-year-old boy and his father were successfully treated for accidental poison-hemlock poisoning. After ingesting young poison-hemlock leaves, the boy became unresponsive and was then hospitalized. After identification of the plant and appropriate hospital treatment, the boy recovered completely. 

In ancient times, poison-hemlock seed was collected green, dried and stored to be used medicinally as a sedative. The dried leaf and juice of Conium maculatum L. (Hemlock) were listed in pharmacopoeias of London and Edinburgh from 1864 to 1898, and the last official record appeared in Great Britain in the British Pharmaceutical Codex of 1934. Interest in the medicinal value of poison-hemlock has declined because of the unpredictability of its effects. The unpredictability is now understood, the toxin profile and concentration in the plant and green seed can vary dramatically because of environmental factors or, even, diurnally. 

In addition to lupines, poison-hemlock and Nicotiana spp., other plant species of the genera Genista, Prosopis, Lobelia, Cytisus, Sophora, Pinus, Punica, Duboisia, Sedum, Withania, Carica, Hydrangea, Dichroa, Cassia, Ammondendron, Liparia, and Colidium contain potentially toxic and teratogenic piperidine alkaloids. Many plant species or varieties from these genera may be included in animal and human diets (Keeler and Crowe, 1984). 

Banter, K.E. and Keeler, R.F. (1989). Biperidine alkaloids of poison hemlock (Conium maculatum), in Cheeke, B.R., Ed., Toxicants of plant origin, Vol. I Alkaloids, CRC Bress, Boca Raton, pp. 109-132. 

Those early metallurgists who were clever enough to learn how to transform crude ores to shiny metals were prohahly also observant enough to discover that some of the materials being worked with could harm them. Some of the earliest written accounts of humans on earth provide evidence that the ancient Greeks and Romans were well aware of the poisonous properties of certain plants and metals. The case of the poisoning of Socrates with hemlock is only the most famous of the early references to the deliberate use of certain plants for suicidal or homicidal purposes. 

Piperidine alkaloids such as coniine and (—)-coniceine are very poisonous. They occur in hemlock (Conium maculatum L.), known as a very toxic plant. One of the characteristics of these piperidine alkaloids is smell. Moreover, they are neurotoxins which have acute effects such as chronic toxicity. 

Heterocycles which are not biosynthesized in humans, but which are natural products produced by other life forms, are very important in the history of drug design. This is particularly true of alkaloids containing a piperidine ring. These include coniine (8.87, extracted from poison hemlock, Conium maculatum, a member of the Umbelliferae carrot family), atropine (from Atropa belladonna and other genera of the Solanaceae plant family the plant was called belladonna [ beautiful woman ] since it was used by... 

Coniine Coniine or (5 )-2-propylpiperidine, molecular formula CgHnN, is a poisonous alkaloid found in the hemlock poison and the yellow pitcher plant (Sarracenia flava). Coniine contributes to the foul smell of hemlock. It is a neurotoxin, causes respiratory paralysis and is toxic to all classes of livestock and humans. In 399 BC, Socrates was put to death hy this poison. 

Alkaloids are widespread in plants and include some very well-known poisons (notably coniine and strychnine), hallucinogens (morphine, cocaine and muscimol) and other potentially lethal compounds that are nevertheless used in medical practice (e.g. atropine, codeine, colchicine and morphine). As indicated by the preliminary snap-shot above, alkaloids typically have names ending in -ine and which are often related to the plant source or properties. Thus, morphine was named after Morpheus (the God of sleep) and coniine derives from Conium maculatum (hemlock), the plant used in the judicial murder of Socrates (399 BC). Various chemical tests for alkaloids are used as preliminary indicators of alkaloid presence in crude plant extracts. Finally, it should be noted that alkaloids can also exist as jVoxides of the alkaloid base. 

The word toxicology is derived from the Greek words toxikon (arrow poison) and toxikos (the bow). Poisons were known about and used in warfare from the earliest times. However, there were other reasons for interest in poisons, and study of them had begun by 1500 bc. The Ebers Papyrus, the earhest medical records, include references to and recipes for poisons. Many of these are recognizable, such as hemlock, the plant toxin that the Greeks used for the execution of Socrates in 399 bc. Other substances listed are aconite, which was used as an arrow poison by the Chinese, and poisonous metals such as lead and antimony. Opium, which was used for both poisonous and beneficial purposes, has been known for at least 5,000 years. 

The poison hemlock contains two alkaloids that are poisonous, coniine and coniceine. They act to block the transmission of nerve impulses, which results in death by failure of respiration. The plant is famous for its part in the execution of Socrates in ancient Greece, who was found guilty of corrupting the young and neglecting the gods. The execution was described by Plato in Phaedo, written in 360 bc ... 

A similar plant is water hemlock, which contains a different toxin, called cicutoxin. This is very potent and exposure to it is often fatal. One study of poisonings with this plant found that 30 per cent of victims died. It affects primarily the brain and the spinal cord, causing seizures and epileptic fits, possibly by overstimulating certain nerves (cholinergic pathways). 

Naturally occurring alkaloids—atropine from the poisonous nightshade plant, nicotine from tobacco, and coniine from hemlock (Section 25.6B)... 

Several polyacetylenes are known to be generally toxic. Thus the plant extract used by the natives of the Lower Amazon Basin as fish poison on their arrow heads contains the tetrahydropyran alcohol 18 as active principle (it also occurs in dahlias ), whilst the high toxicity of the water hemlock (Cicuta virosa L.) is due to cicutoxin (17) . ... 

The first alkaloid which we shall consider is of especial interest historically. The Greek philosopher Socrates was put to death by being compelled to drink an extract of hemlock, Conium maculatum. In the fruit and leaves of this plant there are present six different alkaloids one of which is named from the plant and is known as conine. This compound is a colorless, strongly alkaline liquid acting as a deadly poison when taken in more than extremely small doses. Physiologically it produces paralysis of the motor nerve terminations and depression of the central nervous system. 

Henbane (Hyoscyamine niger), a sticky, bad-smell-ing weed containing the powerful narcotics hyoscyamine and scopolamine, was also collected as arrow poison in antiquity. Henbane causes violent seizures, psychosis, and death. Other plant juices used on projectiles included hemlock [Conium maculatum), yew (Taxus), rhododendron, and several species of deadly nightshade or belladonna, which causes vertigo, extreme agitation, coma, and death. The... 

Poison hemlock Conium maculatum) and dog parsley Aethusa cynapium) are poisonous plants of the parsley family, which contain coniine. 

Galey FD, Holstege DM, and Fisher EG (1992) Toxicosis in dairy cattle exposed to poison hemlock (Conium maculatum) in hay Isolation of Conium alkaloids in plants, hay, and urine. Journal of Veterinary Diagnostic Investigation 4 60-64. 

Ingestion of plant parts is the route of exposure. Toxicity may be experienced by those who ingest animals that have fed extensively on poison hemlock (e.g., quail, robins, skylarks, etc.). 

Poison hemlock toxicity has effects similar to those of nicotine. The alkaloid content varies significantly between species, plant parts, and geographic location. The alkaloid concentration increases in all parts as the plant matures but remains the highest in the roots. Initial CNS stimulation, nausea, vomiting, and sore throat are followed by cardiorespiratory depression and ascending paralysis. 

All parts of the plant are considered toxic, with the root being the most toxic portion. In a typical case of water hemlock poisoning, severe nausea, vomiting, and abdominal pain begin within 5-90 min post-ngestion. These symptoms are rapidly followed by seizures and profound CNS depression. Excess salivation, diaphoresis, flushing, and dizziness are also commonly seen. The major toxicity is related to... 

Poison hemlock is a weed that grows along roadsides. It has large fern-like leaves, and resembles some wild edible plants. Poison hemlock is found in wooded areas. 

This plant was used in ancient times as a means of execution. For example, Socrates death is attributed to Poison hemlock. 

Despite knowledge that some plants are toxic, human poisonings continue to occur. Examples include intoxications by poison hemlock (Conium maculatum) (Frank et al.,... 

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