? Nightshades | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| [image] A flowering Brugmansia x insignis from the US Botanic Garden | ||||||||||
| Scientific classification | ||||||||||
| ||||||||||
| Genera | ||||||||||
| Acnistus Atropa (Deadly nightshade) Brugmansia (angel's trumpet) Calibrachoa Capsicum (chile peppers) Cestrum Chamaesaracha Combera Crenidium Cuatresia Cyphanthera Cyphomandra Datura (jimsonweed) Hyoscyamus (Henbane) Iochroma Lycium (Boxthorn) Lycopersicon (Tomato) Mandragora (mandrake) Nicandra Nicotiana (Tobacco) Petunia Physalis (Tomatillo) Scopolia Solandra Solanum (Potato, Eggplant) Streptosolen ------ For more genera see Solanaceae in The Families of Flowering Plants |
The nightshades (Family Solanaceae) are a family of dicots, many of which are edible, while others are considered poisonous. The name of the family comes from the Latin solanum "nightshade," but the further etymology of that word is unclear; it has been suggested it originates from the Latin Verb "solari," meaning "soothing." This would presumably refer to alleged soothing pharmacological properties of some of the psychoactive Species found in the family. It is more likely, however, that the name comes from the perceived resemblance that some of the flowers bear to the sun and its rays. The Taxon is also sometimes informally referred to as the Potato family. The family includes the Datura or Jimson weed, Eggplant, mandrake, deadly nightshade or belladonna, Capsicum (Paprika, Chile pepper), Potato, Tobacco, Tomato, and Petunia. The Solanaceae family is characteristically ethnobotanical, that is, extensively utilized by humans. It is an important source of food, spice, and medicine. However, Solanaceae species are often rich in alkaloidal glucosides that can range in their Toxicity to humans and animals from mildly irritating to fatal in small quantities.
One of the most important groups of these compounds are called the Tropane alkaloids. The term "tropane" comes from a Genus in which they are found, Atropa (the belladonna genus). The belladonna genus is so named after the Greek Fate, Atropos, who cut the thread of life. This nomenclature betrays the toxicity and lethality that has long been known to be characteristic of these compounds. Tropane alkaloids are also found in the Datura, Mandragora, and Brugmansia genera, as well as many others in the Solanaceae family. Chemically, the molecules of these compounds have a characteristic bicyclic structure and include Atropine, Scopolamine, and Hyoscyamine. Pharmacologically, they are the most powerful known anticholinergics in existence, meaning they inhibit the neurological signals transmitted by the endogenous Neurotransmitter, Acetylcholine. Symptoms of poisoning include mouth dryness, dilated pupils, Ataxia, Urinary retention, hallucinations, convulsions, Coma, and death. Despite the extreme toxicity of the tropanes, they are important drugs when administered in appropriate (and extremely small) dosages. They can reverse Cholinergic poisoning, which can be caused by overexposure to pesticides and Chemical warfare agents such as Sarin and VX. More commonly, they can halt many types of allergic reactions. Scopolamine is a commonly used opthamalic agent for dilating the pupils to facilitate exploration of the eye. They can also be used as antiemetics in people prone to Motion sickness or receiving Chemotherapy. Atropine has a Stimulant effect on the Central nervous system and heart, whereas scopolamine has a Sedative effect. It should be noted that Cocaine is also considered a tropane alkaloid due to its structural similarity to the aforementioned compounds, but its pharmacology is radically different and it does not occur in the Solanaceae family.
The most famous and controversial alkaloid from the Solanaceae family is Nicotine. Like the tropanes, its pharmacology acts on cholinergic neurons, but with the opposite effect (it is an Agonist as opposed to an antagonist). It has a higher specificity for nicotinic acetylcholine receptors than other ACh proteins. Its effects are well known. Nicotine occurs naturally in the Nicotiana or Tobacco genus.
Capsaicin is structurally unrelated to nicotine or the tropanes, and is found in the Capsicum genus, which includes chile peppers such as Tabasco peppers and habaneros. The compound is not appreciably toxic to animals. However, it stimulates specific pain receptors in most mammals, those which sense heat, in the oral mucosa as well as many other epithelial tissues. This causes a sensation of burning not unlike an actual heat or chemical burn. It is used in high concentration as a deterrent in pepper sprays, and sought after for many culinary dishes for its "spiciness." It is thought that the reason one would deliberately induce pain while eating is the rewarding release of endorphins it has been shown to induce. The "hotness" of capsaicin products and foods is expressed in Scoville units. A scoville unit is the factor by which the capsaicin-containing substance must be diluted to render the resulting solution imperceptible to a tester (for example, a teaspoon of a 5,000 Scoville unit Hot sauce would have to be diluted with 4,999 teaspoons of a sugar water solution to render its potential to cause a sensation on the palate gone).
}}>??2}}}}}|??Author|}}} }}??2
}}
}}??2}}}} |. }} Solanacea.
}}