Alkaloids Sentence Examples
The chief constituents of colchicum are two alkaloids, colchicine and veratrine.
Certain of these are alkaloids, others appear to be albumoses.
They possess a delicate Laticiferous layer of protoplasm, with numerous small nuclei lining Tissue the walls, while the interior of the tube (corresponding with the cell-vacuole) contains a fluid called latex, consisting of an emulsion of fine granules and drops of very various substances suspended in a watery medium in which various other substances (salts, sugars, rubber-producers, tannins, alkaloids and various enzymes) are dissolved.
The cell sap contains various substances in solution such as sugars, inulin, alkaloids, glucosides, organic acids and various inorganic salts.
Coca, any preparation or admixture of, containing more than 0.1% but less than 1 of coca alkaloids.Advertisement
In its medicinal use glycerin is an excellent solvent for such substances as iodine, alkaloids, alkalis, &c., and is therefore used for applying them to diseased surfaces, especially as it aids in their absorption.
The limits of space prevent any systematic account of the separation of the rare metals, the alkaloids, and other classes of organic compounds, but sources where these matters may be found are given in the list of references.
The first class includes those substances which require no preliminary treatment, and comprises the amides and ammonium compounds, pyridines, quinolines, alkaloids, albumens and related bodies; the second class requires preliminary treatment and comprises, with few exceptions, the nitro-, nitroso-, azo-, diazoand amidoazo-compounds, hydrazines, derivatives of nitric and nitrous acids, and probably cyanogen compounds.
This, and allied alkaloids, have formed the subject of many investigations by Wyndham Dunstan and his pupils in England, and by Martin Freund and Paul Beck in Berlin.
Hydrolysis gives acetic acid and benzaconine, the chief constituent of the alkaloids picraconitine and napelline; further hydrolysis gives aconine.Advertisement
Other related alkaloids are lycaconitine and myoctonine which occur in wolfsbane, Aconitum lycoctonum.
It has a strong and characteristic odour, and a hot sweetish taste, is soluble in ten parts of water, and in all proportions in alcohol, and dissolves bromine, iodine, and, in small quantities, sulphur and phosphorus, also the volatile oils, most fatty and resinous substances, guncotton, caoutchouc and certain of the vegetable alkaloids.
In regard to methods and apparatus, mention should be made of his improvements in the technique of organic analysis, his plan for determining the natural alkaloids and for ascertaining the molecular weights of organic bases b y means of their chloroplatinates, his process for determining the quantity of urea in a solution - the first step towards the introduction of precise chemical methods into practical medicine - and his invention of the simple form of condenser known in every laboratory.
It is also a decomposition product of many alkaloids.
Auric chloride combines with the hydrochlorides of many organic bases - amines, alkaloids, &c. - to form characteristic compounds.Advertisement
This work led naturally to the synthesis of many terpenes and members of the camphor group; also to the investigation of various alkaloids and natural colouring matters.
A chemical classification of alkaloids is difficult on account of their complex constitution.
Konigs, expressed the opinion that the alkaloids were derivatives of pyridine or quinoline.
This view has been fairly well supported by later discoveries; but, in addition to pyridine and quinoline nuclei, alkaloids derived from isoquinoline are known.
The purely chemical literature on the alkaloids is especially voluminous; and from the assiduity with which the constitutions of these substances have been and are still being attacked, we may conclude that their synthesis is but a question of time.Advertisement
Piperine, conine, atropine, belladonine, cocaine, hyoscyamine and nicotine have been already synthesized; the constitution of several others requires confirmation, while there remain many important alkaloids - quinine, morphine, strychnine, &c. - whose constitution remains unknown.
The following classification is simple and convenient; the list of alkaloids makes no pretence at being exhaustive.
In addition to the above series there are a considerable number of compounds derived from purin which are by some writers classed with the alkaloids.
Reference should also be made to the articles on the individual alkaloids for further details as to their medicinal and chemical properties.
He is known for a long series of researches on the constitution of alkaloids and of the albuminoid bodies, and for the preparation of several new series of platinum compounds and of hyposulphurous acid, H 2 S 2 O 4.Advertisement
Subsequently 3 he subjected the ultra-violet absorption of the alkaloids to a careful 1 Wied.
The bean usually contains a little more than 1% of alkaloids.
As alkaloids are insoluble in alkaline solutions, the oxide and carbonate - especially the former - may be given in alkaloidal poisoning.
It is an exceedingly good solvent, especially for fats, alkaloids and iodine.
Invisible to the microscope, but rendered visible by reagents, are glycogen, Mucor, Ascomycetes, yeast, &c. In addition to these cell-contents we have good indirect evidence of the existence of large series of other bodies, such as proteids, carbohydrates, organic acids, alkaloids, enzymes, &c. These must not be confounded with the numerous substances obtained by chemical analysis of masses of the fungus, as there is often no proof of the manner of occurrence of such bodies, though we may conclude with a good show of probability that some of them also exist preformed in the living cell.
It is to be noted that children, who are particularly susceptible to the influence of certain of the other potent alkaloids, such as morphine and strychnine, will take relatively large doses of atropine without ill-effect.
He also studied the alkaloids and organic acids, introduced a classification of the metals according to the facility with which they or their sulphides are oxidized by steam at high temperatures, and effected a comparison of the chemical composition of atmospheric air from all parts of the world.
The alkaloids are therefore methyl truxillylecgonines.
It is incompatible with mineral acids, alkalis, salts of iron, antimony, lead and silver, alkaloids and gelatin.
Pain may be stopped by removing the cause of irritation, as, for example, by the extraction of a carious tooth or by rendering the nerveendings insensitive to irritation, as by the application of cocaine; by preventing its transmission along the spinal cord by antipyrin, phenacetin, acetanilide, cocaine, &c.; or by dulling the perceptive centre in the brain by means of opium or its alkaloids, by anaesthetics, and probably also, to a certain extent, by antipyrin and its congeners.
The remedy most trusted to in this disease is opium and its alkaloids, morphine and codeine.
Brieger, in his earlier work, found that alkaloids were formed by bacteria in a variety of conditions, and that some of them were poisonous.
These alkaloids he called ptomaines.
Amongst the latter, the vegetable poisons of known constitution, alkaloids, glucosides, &c., are to be placed.
A small amount of opium alkaloids only is manufactured in India.
That these alkaloids are closely related may be suspected from their empirical formulae, viz.morphine = C17H19N03, codeine = C18H21N03, thebaine = C19H21N03.
The presence of the phenanthrene nucleus and the chain system CH 3 N C C follows from the fact that these alkaloids, by appropriate treatment, yield a substituted phenanthrene and also dimethylaminoethanol (CH3)2N CH2 CH20H.
Of the other alkaloids narceine is hypnotic, like morphine and codeine, whilst thebaine, papaverine and narcotine have an action which resembles that of strychnine, and is, generally speaking, undesirable or dangerous if at all well marked.
Tannic acid, for instance, precipitates codeine as a tannate, salts of many of the heavy metals form precipitates of meconates and sulphates, whilst the various alkalis, alkaline carbonates and ammonia precipitate the important alkaloids.
By this process of preparation a considerable portion of the narcotine, caoutchouc, resin, oil or fatty and insoluble matters are removed, and the prolonged boiling, evaporating and baking over a naked fire tend to lessen the amount of alkaloids present in the extract.
The only alkaloids likely to remain in the prepared opium, and capable of producing well-marked physiological results, are morphine, codeine and narceine.
It is a decomposition product of various alkaloids (nicotine, sparteine, cinchonine, &c.), being formed when they are strongly heated either alone or with zinc dust.
In 1810 Gomez of Lisbon obtained a mixture of alkaloids which he named cinchonino, by treating an alcoholic extract of the bark with water and then adding a solution of caustic potash.
In 1820 Pelletier and Caventou proved that the cinchonino of Gomez contained two alkaloids, which they named quinine and cinchonine.
Later quinidine and cinchonidine were discovered, and subsequently several other alkaloids, but in smaller quantity.
The alkaloids exist in the bark chiefly in combination with cinchotannic and quinic acids.
This method is to exhaust the powdered bark with water acidulated with hydrochloric acid and then to precipitate the alkaloids by caustic soda.
The sulphates of the alkaloids thus obtained are not equally soluble in water, and the quinine sulphate can be separated by fractional crystallization, being less soluble in water than the other sulphates.
A mixture of the cinchona alkaloids, consisting principally of cinchonidine sulphate, with smaller quantities of the sulphates of quinine and cinchonine, is sold under the name of "quinetum" at a cheaper rate than quinine.
The chemical constitution of quinine and the allied alkaloids is not definitely settled, although certain relationships are well established.
The other alkaloids of cinchona bark - quinidine, cinchonidine, and cinchonine - also possess similar properties, but all are much less effective than quinine.
Grafting, however, has not been found to answer the purpose, since the stock and the graft have been found to retain their respective alkaloids in the natural proportion just as if growing separately.
The alkaloids are contained, according to Howard, chiefly in the cellular tissue next to the liber.
From analyses of the leaves, bark and root, it appears that quinine is present only in small quantities in the leaves, in larger quantity in the stem bark, and increasing in proportion as it approaches the root, where quinine appears to decrease and cinchonine to increase in amount, although the root bark is generally richer in alkaloids than that of the stem.
In medicine it is largely employed in the form of bromides of potassium, sodium and ammonium, as well as in combination with alkaloids and other substances.
Unlike tannic acid, gallic acid does not precipitate albumen or salts of the alkaloids, or, except when mixed with gum, gelatin.
The oxyquinolines possess a certain importance owing to their relationship to the alkaloids.
Numerous derivatives of isoquinoline are obtained in the decomposition of various vegetable alkaloids.
Some of these, such as resins, gums, essential oils and fats, are readily obtained as natural exudations or by very simple manipulations, while others, such as the alkaloids, glucosides and vegetable acids, often require to be extracted by very complex processes.
The active principles in some of these bitters have been isolated pure, and have been found to be alkaloids or neutral compounds.
Morphine and the other opium alkaloids (codeine, narcotine, laudanine, &c.) have two prominent actions - a narcotic followed by a tetanic action.
Compared with morphine, codeine and the other alkaloids are only slightly narcotizing.
Several of the other alkaloids found in cinchona bark act very much like quinine.
The cinchona alkaloids have a specifically poisonous effect on the parasites of malaria when present in human blood, and are poisonous to all low organisms.
It appears to contain at least two alkaloids - cannabinine and tetano-cannabine - of which the former is volatile.
Ethnic groups in West Africa use plants containing these alkaloids to treat malaria.
It is one of the most useful solvents for extracting alkaloids, the active ingredients in many plant medicines.
Examples of novel natural products from higher plants are given and include alkaloids, terpenoids, phenolics and quinones.
The accumulation of poisonous alkaloids can result in liver sclerosis, which may not be obvious for up to eighteen months.
Not recommended for internal use due to toxic alkaloids.
The bridged ring fragment is common to morphine and related alkaloids of pharmacological importance.
Butchers Broom contains active alkaloids that have many physiological effects.
Ibogaine is one of several alkaloids found in the West African shrub called Tabernanthe Iboga.
A drawback with the vinca alkaloids has been the lack of a medicine that can be given by mouth.
Effects on animals The pyrrolizidine alkaloids are rapidly absorbed from the gastro-intestinal tract.
However, potatoes also contain a number of other inherent toxicants such as tropane alkaloids, terpenoids, saponins, protease inhibitors and lectins.
Studies indicate at least six of these oxindole alkaloids can increase immune function by up to 50% in relatively small amounts.
He was interested in many alkaloids including atropine (1) and the structurally similar cocaine (3) molecule.
Ergot alkaloids The ergot alkaloids The ergot alkaloids have been used to treat migraine attacks for over 50 years.
Leaves produced containing higher levels of poisonous cyanogenic glycosides, alkaloids & other compounds.
The separation of the alkaloids belongs rather to the earlier part of the 19th century, but the administration of these more accurate medications by means of hypodermic injection (see Therapeutics) belongs to the latter.
He was a nephew of Franz Xaver Pettenkofer (1783-1850), who from 1823 was surgeon and apothecary to the Bavarian court and was the author of some chemical investigations on the vegetable alkaloids.
Its use as a local anaesthetic (see Anaesthesia) makes it the most valuable of the coca alkaloids, and it is much used in ophthalmic practice.
Those that are not labeled this way may contain pyrrolizidine alkaloids which can cause liver damage.
Vinblastine and vincristine are plant alkaloids obtained from the periwinkle plant.
However, certain alkaloids present in the herb work similarly to the ephedrine found in ephedra, making some individuals doubt its safety.
These four alkaloids exist in combination in tobacco chiefly as malates and citrates.