The same chromatographic methods are applicable to both the cardenolides and the homologous bufadienolides. In plants, they occur in the form of glycosides. Groups of cardiac steroids Cardioactive steroids are grouped in two categories; Cardenolides Bufadienolides Cardenolides are found. Two classes have been observed in Nature: 1. cardenolides and 2. bufadienolides. The cardenolides have an unsaturated butyrolactone ring.
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Cardioactive glycosides are a kind of steroid glycosides, which act on the human heart. We can distinguish two main aglycone types of the cardioactive glycosides: Medicinally the cardenolide group is more important.
The sugar components of cardioactive glycosides are mainly deoxy-sugars and glucose. If glucose is present in the chain, it can always be found at the end of the chain. The deoxy-sugars are 6-deoxy-sugars e. L-rhamnose, D-fucose, D-digitalose, L-tevetose or 2,6-deoxy-sugars e. Recently, 2-O-methyl and 2-O-acetyl sugars have also been discovered. The biosynthesis of cardenolides and bufadienolides starts from cholesterol C 27 through pregnane derivatives [ by side-chain shortening C 21 ; e.
In the formation of these compounds the incorporation of the active acetyl group of acetyl-CoA plays an important role. Cardenolides dissolve in alcohols eg. Cardioactive glycosides occur rarely in higher plants, their occurrence is not characteristic even at the level of plant families, they are associated rather with some genera or species. Some families with cardiac glycoside-containing taxa are: Cardioactive glycosides exert their pharmacological effect on the heart muscles.
In therapeutic dose they improve cardiac output by increasing the force of heart muscle contraction and increasing the volume of blood pumped into the vascular system positive inotropic action. They can decrease heart rate negative chronotropic action and venous pressure, while diuresis shows an upward tendency.
The action of cardenolic glycosides is always greater than the action of the corresponding aglycones. Cardenolide glycosides are employed in the case of heart insufficiency, which occurs as a consequence of aherosclerosis, hypertonia, asthma cardiale or problems with a cardiac valve valvular or cardiac insufficiency. This biennial or short-lived perennial plant cardnolides native to most of temperate-Europe and North-Africa. It is cultivated as an ornamental and medicinal plant.
Digitalis purpureae folium Purple foxglove leaf.
The drug consists of the dried first- or second-year leaves of Digitalis purpurea L. It contains not less than 0. The characteristic constituents of the drug are cardenolide glycosides 0.
The main glycosides include purpurea glycoside A, purpurea glycoside B czrdenolides purpurea glycoside C, digitoxin, gitoxin and gitalotoxin. Other constituents are steroidal saponins, flavonoids e.
The isolated constituents act on the heart. They have positive inotropic effects. The fine powder of the dried leaves is used in pharmaceutical technology for preparing pellets.
Digitoxin prepared in a pure crystalline form is used to make tablets. The drug or extracts or its pure constituents are very toxic, therefore they should not be used without medical advice.
Cardiac Glycosides |authorSTREAM
This perennial or biennial plant is native to central and south-eastern Europe. It can be cultivated. This plant is protected in Hungary. Digitalis lanatae folium Woolly foxglove leaf. The drug consists of the dried first-year leaves of Digitalis lanata Ehrh. The main glycosides include lanatoside A, lanatoside B, lanatoside C, lanatoside D, lanatoside E, digitoxin, digoxin, acetyldigoxin and glucoverodoxin.
The leaves are used principally for the preparation of lanatosides and digoxin. Digoxin has become the most widely used drug in the treatment of congestive heart failure. Digoxin is more rapidly absorbed from the gastrointestinal tract than the purpurea glycosides. Lanatoside C is less well absorbed than digitoxin but it is less cumulative.
Overall the pharmacological effects of the Digitalis glycosides start approx. Strophanthi semen Strophanthus seed. The drug consists of the bufadienopides seeds without their feathery hairs of Strophanthus kombe Oliver. The cardioactive constituents of the drug in a pure crystalline form are used for the preparation of injections. Cardioactive glycosides of the drug administered in intravenous injections act within a few minutes, and their effect lasts for approx.
Their pharmacological activity is similar to that of Digitalis glycosides, but Strophanthus glycosides do not accumulate, therefore these cardenolides are used in the case of acute cardiac insufficiency as life-saving medicines.
Strophanthus gratus an native to West-Africa. This perennial plant is native to Europe and in the temperate zones of Asia.
It occurs in oak-woods and other deciduous forests. Convallariae herba Lily of the valley. The drug consists of the dried aerial parts collected when the flowers are beginning to open of Convallaria majalis L. The principal glycoside is convallatoxin which on hydrolysis yields strophanthidin and – -rhamnose.
The plant contains several minor cardenolides about 40 glycosides associated with nine different aglycones. Other constituents are steroidal saponins, flavonoids mainly apigenin, luteolin, kaempferol, quercetine and their derivatives and azetidincarboxylic acid. The therapeutic indications include the treatment of cardiac insufficiency, cor pulmonale and cardiac failures associated with oedema formation.
It has diuretic effect. This perennial plant is native to Europe, Caucasus and Siberia. In Hungary it is protected because of its rare occurrence.
It occurs in Mecsek and Bakony mountains. The drug consists of the dried aerial flowering parts of Adonis vernalis L. The principal glycoside is adonitoxin which is the glycoside of adonitoxigenin. The drug also contains strophanthidin-type cardenolides. Other constituents are flavonoid-glycosides, ascorbic acid vitamin C and sugar alcohols.
The cardenolides of the drug are poorly absorbed from the gastrointestinal tract, but they are broken down more quickly than Digitalis cardenolides, therefore they cannot accumulate. The therapeutic indications include nervous cardiac troubles, angina pectoris, cardiac failures associated with oedema formation.
The drug or its extracts and pure constituents are very toxic, therefore they should not be used without medical advice. This perennial woody shrub or small tree is native to South-Europe and West-Asia. It is cultivated as ornamental plant. Nerii folium Oleander leaf. The drug consists of the dried leaves collected during flowering period of Nerium oleander L. The principal glycosides are oleandrin, adynerin, odoroside A and oleasides A-F.
The drug also contains flavonoids such as rutin and kaempferolO-rhamnoglucoside; as well as ursolic and oleanolic acids. The cardenolides of the drug act similarly to the Digitalis cardenolides. The industrial preparations of the drug can be used for the treatment of arrhythmia and circulatory disorders, as well as other cardiac complaints associated with changes in the weather.
Erysimi herba et semen Gray diffuse wallflower flowering shoot and seed. The drug consists of the dried aerial flowering parts and seeds of Erysimum diffusum Ehrh. The characteristic constituents are cardenolides based on strophanthidin aglycone. The seeds contain glucosinolates, sterols and fatty oil. Flavonoids occur mostly in the aerial parts of the plant. Formerly the drug was used for the treatment of mild cardiac insufficiency. At present the plant is not frequently used.
Leonuri cardiacae herba Motherwort, Ph. The drug consists of the whole or cut, dried flowering aerial parts of Leonurus cardiaca L. It contains minimum 0. The characteristic constituents of the drug are bufadienolides. They are glycosides of scillarenin and 5,6-dehydro-scillarenin. Other constituents include diterpenes e. The drug can be used for the treatment of mild cardiac insufficiency and nervous heart complaints.
Leonuri cardiacae herba may be combined with Crategi folium cum flore hawthorn leaf and flower in herbal teas. Adult and elderly daily dose: Baker — Squill Liliaceae. Squill occurs wild as an aggregate of at least six species of varying chromosome number. The plant is native to Mediterranean countries and West Asia. Scillae bulbus Squill bulb. The drug consists of the dried sliced bulbs of Urginea maritima L.
Baker, from which the membranous outer scales have been removed. In white squill there is a mixture of 15 bufadienolides: In red squill the principal glucosides are scillirozide and glucoscillirozide, their aglycone part is scillirosidine.