Alkaloid

alkaloid /al·ka·loid/ (al´kah-loid?) any of a group of organic basic substances found in plants, many of which are pharmacologically active, e.g., atropine, caffeine, morphine, nicotine, quinine, and strychnine.

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ergot alkaloids  a group of chemically related alkaloids either derived from ergot or synthesized; some cause ergotism while others are medicinal.

vinca alkaloids  alkaloids produced by the common periwinkle plant (Vinca rosea); two, vincristine and vinblastine, are used as antineoplastic agents.

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al·ka·loid (lk-loid)

n.

Any of various organic compounds, such as nicotine and morphine, that have basic chemical properties and that usually contain at least one nitrogen atom in a heterocyclic ring.

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Alkaloid

A type of chemical commonly found in plants and often having medicinal properties.

Mentioned in: Chemotherapy

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alkaloid (al´kloid),

n the many nitrogen-containing organic bases derived from plants. They are bitter and physiologically active. A number are useful therapeutic agents.

alkaloid, synthetic,

n a synthetically prepared compound having the chemical characteristics of the alkaloids.

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alkaloid

one of a large group of small organic compounds, mainly derived from amino acids, and containing nitrogen, found in plants. They are water-soluble, usually bitter in taste and are characterized by powerful physiological activity. Examples are morphine, cocaine, atropine, quinine, nicotine and caffeine. The term is also applied to synthetic substances that have structures similar to plant alkaloids, such as procaine. When treated with acids they are converted to water-soluble salts. In cases of poisoning by alkaloids the recommended antidote is tannic acid, but heavy metal salts and iodine also precipitate them. Includes pyrrolizidine and solanaceous alkaloids.