Taste atropine

An alkaloid is a complex organic chemical substance found in plants, which characteristically combines nitrogen with other elements, has a bitter taste, and typically has some toxic, stimulant, analgesic effects. There are many different alkaloids, 30 of which are found in the opium plant. While morphine is the most important alkaloid in opium—for its natural narcotic qualities as well as providing the chemical structure for heroin—another alkaloid, codeine, is also sought after for its medicinal attributes. Other alkaloids include papaverine, narcotine, nicotine, atropine, cocaine, and mescaline. While the concentration of morphine in opium varies depending on where and how the plant is cultivated, it typically ranges from 3 percent to 20 percent. 

Atropina Atropine, C17H23N03, white, acicular crystals, odorless, of bitter taste and alkaline reaction very soluble in alcohol and in chloroform, also soluble in 130 of water at 59°F. It is decomposed by prolonged contact with caustic alkalies and is resolvable into tropine and tropic acid. 

Atropinae Sulphas Atropine sulfate, (C17H23N03)2H2S04, a white powder with a bitter taste and neutral reaction, soluble in 0.4 of water and 6.2 of alcohol at 59°F. 

Despite the supposed universality of bitter taste rejection, many commonly consumed foods and beverages such as fruits, tea, coffee, chocolate, and alcohol have bitterness as a major sensory attribute which, in the overall taste profile of a food, is often appreciated by the consumers. Some alkaloids are certainly responsible for the bitter taste of known food the taste threshold is available only for atropine (0.1 mM), cocaine (0.5 mM), and morphine (0.5 mM) (Table 3.1). 

Atropin forms colorless, silky needles, which are sparingly soluble in cold water, more readily soluble in hot water, very soluble in chloroform. It is odorless, but has a disagreeable, persistent, bitter taste. It is distinctly alkaline, and neutralizes acids with formation of salts. One of these, the sulfate—Atropinse sulphas, IT. S.—is a white, crystalline powder, readily soluble in water, which is the form in which atropin is usually administered. 

There were also some observational foreruimers. In 1932, Snyder (3) described a heritable disability of some people to taste phenylthiocarbamide. In 1943, Savin and Glick (4) noticed a genetic lack of atropine esterase in some rabbits these animals died while eating belladoima leaves, whereas most rabbits were not affected. These cases were perceived as isolated observations they preceded the definition of pharmacogenetics but they helped later investigators to establish pharmacogenetics as a science. 

Oceurs to about 1% in Hyoseyamus mvtieus (f yptian henbane), mandn ora root, henbane, etc. Needles from EtOH. M.p. 108 5°. Sol. EtOH, CHClj, CeHg. Leas sol. H,0, Et,0. [a] f — 22° in 60 EtOH. Resembles atropine in taste and mydriatie action but is physi ally more active. Racemises slowly in EtOH, rapidly on addition of alkali or cm melting. H 0 —> Mroptc acid dZ-tropine. 

Some of our most important medicinal drugs have originated from plants. Lewis and Clark took Peruvian bark, or cinchona bark, with them as a medicine on their 1804 expedition from the eastern United States to the Pacific Coast and back. The bitter essence of cinchona bark is quinine, an amine drug that has been used to combat malaria. Quinine is responsible for the bitter taste of tonic water, a carbonated beverage (Figure 16.4). Some other amines that come from plants are caffeine (from coffee, a stimulant), atropine (from the deadly nightshade, used to dilate the pupil of the eye for eye exams), and codeine (from the opium poppy, used as a painkiller). 

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