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IUPAC name (5ξ,8ξ,9ξ,12ξ,14ξ)-4,14,15,16,20-Pentahydroxy-4,9-epoxycevan-3-yl acetate | |
Other names Cevane-3β,4β,14,15α,16β,20-hexol, 4,9-epoxy-, 3-acetate | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
PubChem CID | |
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CompTox Dashboard (EPA) | |
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Properties | |
C29H45NO8 | |
Molar mass | 535.678 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Zygacine is a steroidal alkaloid of the genera Toxicoscordion , Zigadenus , Stenanthium and Anticlea of the family Melanthiaceae. [1] These plants are commonly known and generally referred to as death camas. Death camas is prevalent throughout North America and is frequently the source of poisoning for outdoor enthusiasts and livestock due to its resemblance to other edible plants such as the wild onion. [1] Despite this resemblance, the death camas plant lacks the distinct onion odor and is bitter to taste.
The effects of zygacine consumption are lethal. Symptoms in humans include nausea, vomiting, slowed heart rate, low blood pressure and ataxia. [2] Poisoned animals suffer from loss of appetite, lack of coordination, digestive and excretory disorders, labored breathing, racing heartbeat and frequently death. [2]
Suggested treatment of poisoning in humans include administering dopamine and atropine to the patient. [3] For animals, treatment consists of atropine, picrotoxin and activated charcoal. [4]
Scientists first attempted to determine the toxic ingredient(s) of alkaloid extracts of Zygadenus plants in 1913. [5] They were able to isolate zygadenine, the alkamine present in alkaloids of the genus Zigadenus. [5] The minimal pharmacological activity of zygadenine led to subsequent investigations of Zygadenus venenosus and Zygadenus paniculatus which revealed that zygacine was one of the primary toxic components. [5] Although it was first isolated in 1913, the structure and configuration of zygacine weren't reported until 1959. [6]
Zygacine poisoning via ingestion of death camas had been reported in both livestock and humans as early as the nineteenth century. [7] It has been for many years - and continues to be - responsible for the poisonings and deaths of many types of livestock including sheep, cattle, horses, pigs and fowl. [8] A one-time loss of 500 sheep was reported in 1964 [9] and in 1987, 250 sheep died from death camas poisoning. [10] Poisonings generally occur in the early spring when the death camas plant is most abundant and other food sources for livestock are limited. [11] Sheep seem to be poisoned most often due to their grazing behavior as they pull up and consume the entire plant. [2] Moist conditions are more conducive to cattle poisoning as it makes it easier to extract the plant from the soil. [2] Humans have also fallen victim to zygacine poisoning by mistaking the death camas for other edible plants. In 1994, a man presented to the emergency department with gastrointestinal symptoms, a depressed heart rate and low blood pressure after inadvertently eating plant material derived from a species of Zigadenus. [12] He recovered after being treated.
Zygacine is a highly potent compound with an LD50 of 2.0 +/- 0.2 mg/kg when administered intravenously and 132 +/- 21 mg/kg when administered orally to mice. [11] The lethal dose conversions for a 60 kg human, 600 kg cow and 80 kg sheep are included in the table below.
Subject | Human (60 kg) | Cattle (600 kg) | Sheep (80 kg) |
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IV Administration | 108 mg - 132 mg | 1.08 g - 1.32 g | 144 mg - 176 mg |
Oral Administration | 6.66 g - 9.18 g | 66.60 g - 91.80 g | 8.88 g - 12.24 g |
General symptoms of zygacine poisoning among humans and animals alike include but are not limited to gastrointestinal and cardiovascular ailments such as nausea, vomiting, diarrhea and irregular heartbeat. [12]
Within an hour of ingesting the toxic death camas plant, a human will begin to experience nausea, vomiting, abdominal cramping and diarrhea. [12] Other symptoms include low heart rate and blood pressure as well as ataxia and muscle spasms. [12]
Initial signs of zygacine poisoning in animals include frothy salivation around the mouth, followed by nausea and vomiting. [13] Severely poisoned animals will suffer from a loss in appetite, lack of coordination and depression. [2] Sheep, in particular, will stand with their heads and ears dropped with their backs are arched. [2] Intestinal peristalsis, a condition characterized by involuntary movement of the muscles in the digestive tract, results in frequent defecation and urination. [13] Fatally poisoned animals develop a weak and rapid pulse and labored breathing. [13] The shuddering struggle to breathe may be confused with convulsions. [13]
Zygacine is a steroidal alkaloid of the veratrum type. [14] Veratrum alkaloid compounds act by attaching to voltage-gated sodium ion channels, altering their permeability. [15] Veratrum alkaloids cause affected sodium channels to reactivate 1000x slower than unaffected channels. [15] They also block inactivation of sodium channels and change their activation threshold so they remain open even at resting potential. [15] As a result, sodium concentrations within the cell rise, leading to increased nerve and muscle excitability. [12] This biochemical activity causes muscle contractions, repetitive firing of the nerves and an irregular heart rhythm from stimulation of vagal nerves which control the parasympathetic functions of the heart, lungs and digestive tract. [12]
There is no antidote for zygacine poisoning so only the symptoms arising from poisoning in humans are usually treated, of which bradycardia and hypotension are prioritized. These symptoms are initially treated with atropine, a muscarinic receptor antagonist. [16] In a case study in which atropine was not sufficient, hypotension and bradycardia were successfully treated using dopamine. [17] Dopamine increases renal sodium excretion, blood pressure and the heart rate. [18]
For animals, reported effective treatment of zygacine poisoning consists of injection of 2 mg of atropine sulfate and 8 mg of picrotoxin per 45 kg of body weight. [4] Intravenous fluid therapy is used to increase blood pressure. [4] A stomach tube can be used to relieve stomach pressure in bloated animals. [4]
Aconitine is an alkaloid toxin produced by various plant species belonging to the genus Aconitum, known also commonly by the names wolfsbane and monkshood. Monkshood is notorious for its toxic properties.
Conium is a genus of flowering plants in the family Apiaceae. As of December 2020, Plants of the World Online accepts six species.
Melanthieae is a tribe of flowering plants within the family Melanthiaceae. Molecular phylogenetic studies in the 21st century have resulted in a large-scale reassignment of many of its species to different genera; in particular the genus Zigadenus (deathcamases) has been restricted to a single species, Zigadenus glaberrimus. Plants contain alkaloids, making them unpalatable to grazing animals; many are very poisonous to both animals and humans.
Solanine is a glycoalkaloid poison found in species of the nightshade family within the genus Solanum, such as the potato, the tomato, and the eggplant. It can occur naturally in any part of the plant, including the leaves, fruit, and tubers. Solanine has pesticidal properties, and it is one of the plant's natural defenses. Solanine was first isolated in 1820 from the berries of the European black nightshade, after which it was named. It belongs to the chemical family of saponins.
Toxicoscordion venenosum, with the common names death camas and meadow death camas, is a species of flowering plant in the family Melanthiaceae. It is named for its well known toxic qualities, with both its common names and its scientific name referencing this. Because its nectar is also poisonous, it is mainly pollinated by the death camas miner bee, which specializes in collecting the toxic pollen for its young. It is native to western North America from New Mexico to Saskatchewan and west to the Pacific Ocean.
Cicutoxin is a naturally-occurring poisonous chemical compound produced by several plants from the family Apiaceae including water hemlock (Cicuta species) and water dropwort (Oenanthe crocata). The compound contains polyene, polyyne, and alcohol functional groups and is a structural isomer of oenanthotoxin, also found in water dropwort. Both of these belong to the C17-polyacetylenes chemical class.
Taxus cuspidata, the Japanese yew or spreading yew, is a member of the genus Taxus, native to Japan, Korea, northeast China and the extreme southeast of Russia.
Veratridine is a steroidal alkaloid found in plants of the lily family, specifically the genera Veratrum and Schoenocaulon. Upon absorption through the skin or mucous membranes, it acts as a neurotoxin by binding to and preventing the inactivation of voltage-gated sodium ion channels in heart, nerve, and skeletal muscle cell membranes. Veratridine increases nerve excitability and intracellular Ca2+ concentrations.
Veratrum is a genus of flowering plants in the family Melanthiaceae. It occurs in damp habitats across much of temperate and subarctic Europe, Asia, and North America.
Methyllycaconitine (MLA) is a diterpenoid alkaloid found in many species of Delphinium (larkspurs). In common with many other diterpenoid alkaloids, it is toxic to animals, although the acute toxicity varies with species. Early research was focused on identifying, and characterizing the properties of methyllycaconitine as one of the principal toxins in larkspurs responsible for livestock poisoning in the mountain rangelands of North America. Methyllycaconitine has been explored as a possible therapeutic agent for the treatment of spastic paralysis, and it has been shown to have insecticidal properties. Most recently, it has become an important molecular probe for studying the pharmacology of the nicotinic acetylcholine receptor.
Veratrum album, the false helleborine, white hellebore, European white hellebore, or white veratrum is a poisonous plant in the family Melanthiaceae. It is native to Europe and parts of western Asia.
Anticlea elegans, formerly Zigadenus elegans, is also known as mountain deathcamas, elegant camas or alkali grass. It is not a grass, but belongs to the trillium family, Melanthiaceae.
Tutin is a poisonous plant derivative found in New Zealand tutu plants. It acts as a potent antagonist of the glycine receptor, and has powerful convulsant effects. It is used in scientific research into the glycine receptor. It is sometimes associated with outbreaks of toxic honey poisoning when bees feed on honeydew exudate from the sap-sucking passion vine hopper insect, when the vine hoppers have been feeding on the sap of tutu bushes. Toxic honey is a rare event and is more likely to occur when comb honey is eaten directly from a hive that has been harvesting honeydew from passionvine hoppers feeding on tutu plants.
Senecionine is a toxic pyrrolizidine alkaloid isolated from various botanical sources. It takes its name from the Senecio genus and is produced by many different plants in that genus, including Jacobaea vulgaris. It has also been isolated from several other plants, including Brachyglottis repanda, Emilia, Erechtites hieraciifolius, Petasites, Syneilesis, Crotalaria, Caltha leptosepala, and Castilleja.
Zigadenus is a genus of flowering plants now containing only one species, Zigadenus glaberrimus, the sandbog death camas, found in the southeastern United States from Mississippi to Virginia. Around 20 species were formerly included in the genus, but have now been moved to other genera.
Pyrrolizidine alkaloidosis is a disease caused by chronic poisoning found in humans and other animals caused by ingesting poisonous plants which contain the natural chemical compounds known as pyrrolizidine alkaloids. Pyrrolizidine alkaloidosis can result in damage to the liver, kidneys, heart, brain, smooth muscles, lungs, DNA, lesions all over the body, and could be a potential cause of cancer. Pyrrolizidine alkaloidosis is known by many other names such as "Pictou Disease" in Canada and "Winton Disease" in New Zealand. Cereal crops and forage crops can sometimes become polluted with pyrrolizidine-containing seeds, resulting in the alkaloids contaminating flour and other foods, including milk from cows feeding on these plants.
Toxicoscordion nuttallii is a species of poisonous plant native to the south-central part of the United States.
Toxicoscordion fontanum, common name small-flower death camas, is a rare plant species known only from serpentine marshes in California. It is found primarily in the Coast Ranges from Mendocino County to San Luis Obispo County, with an additional report of an isolated population in the Sierra Nevada foothills in Kern County east of Bakersfield.
Taxine alkaloids, which are often named under the collective title of taxines, are the toxic chemicals that can be isolated from the yew tree. The amount of taxine alkaloids depends on the species of yew, with Taxus baccata and Taxus cuspidata containing the most. The major taxine alkaloids are taxine A and taxine B although there are at least 10 different alkaloids. Until 1956, it was believed that all the taxine alkaloids were one single compound named taxine.
Lantadenes are naturally occurring pentacyclic triterpenoids found in the Lantana camara plant. They are known to be poisonous to livestock that graze on the leaves of the plant, causing photosensitivity and hepatotoxicity as major symptoms. Lantadenes A and B are the most abundant and bioactive triterpenoids found in the Lantana camara leaves.