alkaloid

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alkaloid

 [al´kah-loid]
one of a large group of organic, basic substances found in plants. They are usually bitter in taste and are characterized by powerful physiologic 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.
vinca a's see vinca alkaloids.

al·ka·loid

(al'kă-loyd),
Originally, any one of hundreds of plant and fungal products distinguished by alkaline (basic) reactions, but now restricted to heterocyclic nitrogenous and often complex structures possessing pharmacologic activity; their trivial names usually end in -ine (for example, morphine, atropine, colchicine). Alkaloids are synthesized by plants and are found in the leaf, bark, seed, or other parts, usually constituting the active principle of the crude drug; they are a loosely defined group, but may be classified according to the chemical structure of their main nucleus. For medicinal purposes, due to improved water solubility, the salts of alkaloids (for example, morphine sulfate, codeine phosphate) are usually used. see also individual alkaloid or alkaloid class.
Synonym(s): vegetable base

alkaloid

(ăl′kə-loid′)
n.
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.

alkaloid

Herbal medicine
Any of a number of medicinally active compounds produced by plants; alkaloids are often active in small amounts and toxic in large amounts; well-known alkaloids produced by plants include caffeine, codeine, morphine, nicotine, quinine and strychnine.

al·ka·loid

(al'kă-loyd)
Originally, any one of hundreds of plant products distinguished by alkaline (basic) reactions, but now restricted to heterocyclic nitrogen-containing and often complex structures possessing pharmacologic activity; their trivial names usually end in -ine (e.g., morphine, atropine, colchicine). Alkaloids are synthesized by plants and are found in the leaf, bark, seed, or other parts, usually constituting the active principle of the crude drug; they are a loosely defined group but may be classified according to the chemical structure of their main nucleus. For medicinal purposes, due to improved water solubility, the salts of alkaloids are typically used.

Alkaloid

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

al·ka·loid

(al'kă-loyd)
Heterocyclic nitrogenous and often complex structures possessing pharmacologic activity; synthesized by plants and are found in the leaf, bark, seed, or other parts, usually constituting the active principle of the crude drug; they comprise a loosely defined group.