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.
References in periodicals archive ?
There are considerable variations in the venom alkaloid chemistry among different castes (workers, soldiers, and female alates) in some fire ant species (Brand et al.
Alkaloid Sambiloto as an immunomodulator administered to rats after infected with Salmonella typhimurium:
Rodriguez-Nogales et al., "Intestinal antiinflammatory effects of total alkaloid extract from Fumaria capreolata in the DNBS model of mice colitis and intestinal epithelial CMT93 cells," Phytomedicine, vol.
The phytochemical studies indicated that GE contains a series of active constituents such as alkaloids, triterpenes, iridoid, and phenylpropanoids [5-8].
Conclusion: The present study demonstrated that the alkaloid extract from MS alleviates ethanol withdrawal severity with no side effect on REM sleep.
Intraspecific variability in the alkaloid metabolism of Galanthus elwesii.
Considering the above observations, the following analytical method including the best conditions for the alkaloid determination was composed: capillary voltage 3500 V, fragmentor energy from v 150, gas temperatures from 350[degrees]C, drying gas flows from 12L/min, nebulizer from 35 psig, skimmer from 65 V, and collision energies CID from 20 to 30 V.
Among the analyzed species, E is the dominant alkaloid in E.
Maximum alkaloid production measured was at pH 5.0 (2 mg/l) and at 25C (2.01 mg/l) (Fig.
Partial reconstruction of the ergot alkaloid pathway by heterologous gene expression in Aspergillus nidulans.