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 ?
Results: The sleep analysis revealed that alkaloid extract from MS did not change any REM parameters which included average duration of each REM episode, total REM time, number of REM episode and REM latency whereas fluoxetine significantly suppressed all REM parameters and delayed REM latency.
The purified alkaloid alseroxylon extract would be less than 5 milligrams per day and in most cases less than 2.
Of its business undertakings in the USA, Alkaloid is especially proud of patenting its technology for the production of the medication Novamorph in 2003 and of its close cooperation with AVEDA, a reputable member of Este Lauder Group, in the production of organic teas, which began in 2005 and has since progressed well.
Robert Vander Meer, research leader in the Imported Fire Ant and Household Insects Unit at the Agricultural Research Service's Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, Florida, partnered with other researchers to determine whether toxic alkaloids from the brilliantly colored skin of poison frogs would deter fire ants.
In addition to tropane alkaloids key products include Calcium sennosides, Colchicine, Enoxolone, Hysocine-N-Butylbromide, Nicotine, Thiocolchicoside and Vinpocetine.
Furthermore, the absence of abortion and vaginal bleeding in the alkaloid-treated animals which were hitherto observed with the crude extract in our previous study suggest zero abortifacient activity for the alkaloid.
Alkaloid fraction of leaves of Achyranthesaspera Linn increased apoptosis in mammary cancer cells (table 1).
Once the defensive alkaloid compound was identified, the researchers observed the behaviour of ants in its presence.
50] values were calculated for different oxindole alkaloid compositions.
A handful of ancient plant groups, including the poppy and buttercup families, produce the class of alkaloids that morphine belongs to, called benzylisoquinoline alkaloids.
Naturally occurring alkaloids such as morphine and the anti-cancer drug vinblastine are already extracted from plants for medical applications.
The results demonstrated that mitragynine as major alkaloid from Mitragyna speciosa reduced the locomotor activity of the rats treated with 1.