Specification & Spread
The seeds of strophanathus — semina strophanthi
Strophanthus kombe — strophanthus kombe oliv.
Dogbane family — аросупасеае.
It is a woody vine with subopposite elliptical or ovoid leaves.
It has pentamerous flowers in cymes. Its yellow petals are elongated in long flagging cordlike and often twisted ends.
The fruit is a two-leaf, reaching a length of 1 m and consists of two oppositely arranged spindle-shaped leaflets containing numerous seeds.
The seeds are oblong-elongated, oblate and pubescent with pressed sericate hairs. It is rounded at one end and acuminate at the other, turning into an axis carrying a feather. Their length (without a feather) is 12-18 mm, width is 3-6 mm and thickness is 2-3 mm. Poisonous (!).
Spreading. In the wild form it grows in East Africa along the Zambezi River and in tropical rain forests. In insignificant quantities it is cultivated in tropical regions of Africa and India. It is allowed to harvest seeds of other species of strophanthus which are also grown in tropical Africa (S. gratus (Hook.) Franch and S. hispidus DC). In our country, the cultivation of tropical vines is impossible, so scientists are looking for analogues in the domestic flora. There were found plants in which the aglycone of cardiotonic glycosides is strophanthidine ,as in strophanthus. These are the species of lily-of-the-valley, yellow cress, gold-shining pheasant's eye and etc. However, the sugar component of the glycosides of these plants differs from the carbohydrate part of the glycosides of the strophanthus. Therefore the effect of these glycosides on the heart muscle is somewhat different than the glycosides of the strophanthus.
The need for strophanthus seeds is satisfied by importing.
Habitat. In tropical rain forests and on the edges.
The seeds of strophanthus kombe contain cardiac (cardiotonic) glycosides (up to 8-10%) that are the derivatives of strophanthidine.
The main one is the glycoside K-strophanthoside, which is a trioside (2-3%). The literal prefix K means a source of raw materials (see Kombe).
The sugar part of K-strophantozid consists of:
- beta glucose and
- alpha glucose.
With the stepwise hydrolysis, the secondary glycoside beta K-strophanthin is obtained, which is also a valuable preparation.
Upon the further hydrolysis, cymarin glycoside is formed.
Finally, the cymarose sugar is cleaved off and the aglycone strophanthidine remains, containing the aldehyde group at position C10.
Harvesting and storage of raw materials
Harvesting. It is needed to collect at the time of ripening, free the seeds and remove the axis with the feather.
Drying. In the shadow.
Storage. It is separated from other types of raw materials under lock and key. In pharmacies it is stocked in well-closed cans, in warehouses it is in boxes. The biological activity of seeds is monitored annually. The biological activity of 1 g of strophanthus seeds should be at least 2000 frog unit or 240 cat unit.
External signs of raw materials
The seeds are oblong-elongated in shape, complanated, with a rounded lower end and a acuminate upper one, turning into an axis of a feather, usually broken off at the base. The seed length is 12-18 mm, width is 3-6 mm, thickness is 2-3 mm. The seeds are covered with sericeous subpressed hairs.
The seed colour is greenish grey. After erasing the hairs, the seeds become yellowish brown or light brown.
The smell is weak.
Due to the strong toxicity, taste is not determined(!).
Properties and application
Pharmacotherapeutic group. Cardiotonic agent (cardiac glycosides).
The pharmacological properties of strophanthus
Strophanthin is characterized by high efficiency, speed and short duration of action.
The effect while intravenous administration appears after 5-10 minutes and reaches a maximum after 15-30 minutes.
The systolic effect is especially pronounced in strophanthin. It has relatively little effect on heart rate and conductivity of the His bundle.
Application of strophanthus
The seeds of strophanthus are used to obtain preparations.
K-strophanthin beta consists of aglycone strophanthidine and sugar residue (beta-glucose and cymarosis).
K-strophanthoside additionally has an alpha-D-glucose residue.
The glycosides of strophanthus seeds are the main representatives of the «polar» cardiac glycosides.
It is applied in acute cardiovascular insufficiency, including on the basis of acute myocardial infarction; in severe forms of chronic circulatory failure of II and III stages, especially with the ineffectiveness of treatment with digitalis preparations. This strophanthin, due to the weak influence on the function of the vagus nerve, is assigned with cardiac decompensation with a normal heart rate or bradystolic form of atrial fibrillation. When the tachycardic form of atrial fibrillation, digoxin and celanid are more effective.
With an overdose of strophanthin, premature beats, bigeminy, rhythm dissociation may occur. In these cases it is necessary to reduce the dose with the next injections, increase the intervals between individual infusions and prescribe potassium preparations. With a sudden slowdown of the pulse, the injection is stopped. Nausea and vomiting are possible.
Violant organic changes in the heart and blood vessels, acute myocarditis, endocarditis, expressed cardiosclerosis. It is necessary to be careful having thyrotoxicosis and atrial premature beats because of the possibility of its transition to atrial fibrillation.