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Any of various organic compounds that are usually basic and contain at least one nitrogen atom in a heterocyclic ring, occurring chiefly in flowering plants. Many alkaloids, such as nicotine, quinine, cocaine, and morphine, are known for their poisonous or medicinal attributes.
al′ka·loi′dal (-loid′l) adj.
(Elements & Compounds) any of a group of nitrogenous basic compounds found in plants, typically insoluble in water and physiologically active. Common examples are morphine, strychnine, quinine, nicotine, and caffeine
1. any of a large class of bitter-tasting, nitrogen-containing, alkaline ring compounds common in plants and including caffeine, morphine, nicotine, quinine, and strychnine.adj.
2. resembling an alkali; alkaline.
Any of a large class of complex organic compounds that contain nitrogen and mostly occur in plants. Alkaloids have a wide range of physiological effects and many uses in medicine, but they can also be toxic. Morphine, quinine, and nicotine are all alkaloids.
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|Noun||1.||alkaloid - natural bases containing nitrogen found in plants|
atropine - a poisonous crystalline alkaloid extracted from the nightshade family; used as an antispasmodic and to dilate the eye pupil; also administered in large amounts as an antidote for organophosphate nerve agents or organophosphate insecticides
hyoscyamine - a poisonous crystalline alkaloid (isometric with atropine but more potent); used to treat excess motility of the gastrointestinal tract
pilocarpine - cholinergic alkaloid used in eyedrops to treat glaucoma
hyoscine, scopolamine - an alkaloid with anticholinergic effects that is used as a sedative and to treat nausea and to dilate the pupils in ophthalmic procedures; "transdermal scopolamine is used to treat motion sickness"; "someone sedated with scopolamine has difficulty lying"
physostigmine - used in treatment of Alzheimer's disease and glaucoma
cinchonine - an alkaloid derivative of the bark of cinchona trees that is used as an antimalarial drug
ephedrine - white odorless powdered or crystalline alkaloid from plants of the genus Ephedra (especially Ephedra sinica) or made synthetically; used as a bronchodilator to treat bronchitis and asthma
ergonovine, Ergotrate Maleate - an alkaloid derived from ergot (trade name Ergotrate Maleate) that is less toxic than ergot; induces muscular contraction of the uterus and is administered after childbirth or abortion
ergotamine - an alkaloid derived from ergot that is less toxic than ergot; causes constriction of blood vessels and is used to treat migraine
pseudoephedrine - poisonous crystalline alkaloid occurring with ephedrine and isomorphic with it
nicotine - an alkaloid poison that occurs in tobacco; used in medicine and as an insecticide
strychnine - an alkaloid plant toxin extracted chiefly from nux vomica; formerly used as a stimulant
brucine - a bitter alkaloid poison resembling strychnine and extracted from nux vomica
betaine - a sweet tasting alkaloid that occurs in sugar beets
organic compound - any compound of carbon and another element or a radical
caffein, caffeine - a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects
rauwolfia - any of several alkaloids extracted from the shrub Rauwolfia serpentina