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

/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.
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.

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

[al′kəloid]
Etymology: Ar, al + galiy; Gk, eidos, form
any of a large group of nitrogen-containing organic compounds produced by plants, including many pharmacologically active substances, such as atropine, caffeine, cocaine, morphine, nicotine, and quinine.

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.

alkaloid (al´kəloid),

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.

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.
References in periodicals archive ?
The alkaloid fractions were analyzed by gas chromatographymass spectrometry (GC-MS).
Alkaloid and terpenoids are main secondary metabolites that have many physiological and pharmacological properties to living cells (56).
Even though whole body solvent-soak extraction is often used for fire ant venom alkaloid analysis, some researchers have questioned whether soaking the whole body in hexane can accurately recover the same venom composition that is released from the sting.
Alkaloid Sambiloto as an immunomodulator administered to rats after infected with Salmonella typhimurium:
Alkaloids were present in the highest quantity in fruit extract (13.
2012) Antitussive, expectorant and anti-inflammatory activities of four alkaloids isolated from Bulbus of Fritillaria wabuensis.
After concentration in vacuum, the purified alkaloid fraction was obtained as a brown residue and the yield was 0.
Among the analyzed species, E is the dominant alkaloid in E.
citrinum strain was determined as the best producer of ergot alkaloids with ergot alkaloid concentration 1.
The ergot alkaloid production profile of this species is very significant, specially the ergotamine and ergocriptine.
However, Amerindian tribes had discovered the effects of the alkaloids long before then, when they learned how to secure alkaloid secretions from the skin of poison frogs of one genus to make poison darts for hunting.