alkaloid

(redirected from alkaloidal)
Also found in: Dictionary, Thesaurus, Encyclopedia.

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 reproductive consequences associated with inducible alkaloidal responses in wild tobacco.
Ontogeny and cytochemistry of alkaloidal vesicles in laticifers of Papaver somniferum, American Jour.
Anti-bacterial, antifungal, anti-plasmodial, and cytotoxic activities have been reported for the root bark alkaloidal extract of the plant Albertisia villosa and an isolated bisbenzylisoquinoline--cycleanine, which validates its traditional use in Congolese medicine for treatment of malaria and other infectious diseases (Lohombo-Ekomba, M.
divaricata as well as its potential therapeutic benefits especially of the alkaloidal and non-alkaloidal constituents.
Anti-inflammatory Activities of Methanolic Extract and Alkaloidal Components from Corydalis Tuber, Biol.
The alkaloidal fraction from the roots of Cyclea barbata contain two new bisbenzylisoquinoline alkaloids, namely, (-)-2'-norlimacine and (+)-cycleabarbatine (Guinaudeau et al.
The hypoglycemic activity of alkaloidal fraction of the plant has been demonstrated (Patel and Mishra, 2011).
In this communication, we present a comparative study of the leishmanicidal activity of the crude ethanolic extract, its fractions and also the two major alkaloidal metabolites (-)-cassine/(-)-spectaline, trying to establish a relationship between the presence of piperidine alkaloidal constituents and leishmanicidal activity.
Alkaloidal responses to damage in Nicotiana native to North America.
Plant antitumor agents-1, the isolation and structure of camptothecin, a novel alkaloidal leukemia and tumor inhibitor from Camptotheca acuminata.
Therefore, AChE inhibition of the whole alkaloidal extract was investigated.