Transcript Lecture №14
MP and MPM containing steroidal saponins Saponins (Latin sapo, soap) are characterized by their property of producing a frothing aqueous solution, possessing a high surface activity. They also have haemolytic properties, and then injected into the blood stream are highly toxic. They can cause the death of cold blooded animals such as frogs, worms and fish even in 1:1000000 dilution. Their molecule consists of the aglycone called sapogenin and carbohydrates (sugars). According to the structure of aglycone two kinds of saponins are recognised- the steroidal ( C27 commonly tetracyclic triterpenoids - neutral) and the pentacyclic triterpenoids types (C30, acidic properties ). Both of these have a glycosidal linkage at C3 and have a common biogenetic origin via mevalonic acid and isoprenoid units. Steroidal saponins Iso-line monodesmoside Normal line monodesmoside cyclopentane perhydro phenanthrene Steroidal saponins Steroidal saponins are less widely distributed in nature than the pentacyclic triterpenoid type. Sapogenins are derivatives of cyclopentanperhydropenantrene. Some species of Strophantus and Digitalis contain both steroidal saponins and cardiac glycosides. Steroidal saponins are found in plants of such families as: Liliaceae, Amaryllidaceae, Dioscoreaceae, Schrophulariaceae, Zygophyllaceae etc. Steroidal saponins are of great pharmaceutical importance because of their relationship to compounds such as the sex hormones, cortisone, diuretic steroids, vitamin D and the cardiac glycosides. Some are used as starting materials for the synthesis of these compounds. Triterpenoid saponins In many triterpenoid saponins oleanolic acid is sapogenin. They are abundant in many dicotyledonous families, particularly the Caryophyllaceae, Sapindaceae, Polygalaceae and Sapotaceae, Ranunculaceae, Papaveraceae, Araliaceae, Rubiaceae and Compositeae. Altogether some 70 families are involved. Triterpenoidal Saponins 1. Saponins, whose aglycones are represented by pentacyclic compounds α-amyrin α-amyrin lupeol hopan Saponins may be containing from 1 to 11 monosaccharides and their derivatives. D-glucose, D-galactose, D-xylose, L-rhamnose, D-glucoronic and D-galacturonic acids are the most common. They form linear or branched chains, and may join by means of hydroxyl and carboxyl groups to aglycones in various position. Methods of obtaining For obtaining of saponins from MPM water or diluted alcohols are used. Aglycones are well soluble in organic solvents. Biological action Saponins stimulate secretion of bronchial glands, enhance cough center and thus are widely used as expectorants. Also they are used as adaptogenic drugs (ginseng, aralia), regulate water-mineral balance (glycyrrhiza), have antiinflammatory, diuretic and laxative properties. Steroidal saponins are source for production of corticosteroids (cortisone hormones) and in treatment of atherosclerosis. Dioscoreae rhizomata cum radicibus Wild Yam rhizome with root Dioscorea nipponica Wild Yam, Makino, China root, Devil’s Bones Dioscoreaceae Constituents. An acrid resin, steroid saponin dioscin, starch, calcium oxalate, etc. Uses. Represents rich source of the principles used as a cortisone precursors. Folia Agavae Agava Americana- Century plant Agavaceae Constituents. Leaves contain steroidal saponins- gecogenin, manogenin, gitogenin. Uses. Leaves are used for the production of steroidal hormones. Herba Tribuli terrestris Tribulus terrestris- cathead, caltrop Zygophyllaceae Constituents. Herb contains steroidal glycosides (2%) and dioscine, tihogenin, hecogenin and gracyllin are among them; flavonoid glycosides, tannins, ascorbic acid. Uses. Liquid extract has diuretic, antisclerotic and hypotensive effects, stimulates secretion of gastric juice. Tribusponin is used for prevention and treatment of atherosclerosis. Drugs also have anabolic properties (tribestan). Foenugraeci semina Fenugreek seed Trigonella foenum-graecumFenugreek (Greek Hay Seed, Bird’s Foot) Fabaceae Constituents. Mucilage (galactomannan - about 28 %.), trigonelline, choline, an odorous oil and proteins (about 22 %.), steroid saponin, that have diosgenin as aglicon. Uses. Main application is for the production of steroidal hormones. Extract is part of Phytolysin. The ground drug is employed in domestic medicine for the preparation of poultices, enemata, and plasters; in veterinary cattle and condition powders.