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Transcript of SAPONİNS
PHARMACOLOGICAL AND BIOLOGICAL PROPERTIES
Saponins are high molecular-weight glycosides, consisting of a sugar moiety linked to a
triterpene or steroid aglycone.
The classical definition of saponins is based on their surface activity; many saponins havedetergent properties, give stable foams in water, show haemolytic activity,
have a bitter taste and are
toxic to fish.
Some saponin containing plants have been employed for hundreds of years as soaps and this fact reflected in their common names: soapwort (saponaria officinalis), soaproot(Chlorogalum pomeridianum), soapberry(Sapindus saponaria), soapnut(sapindus mukurossi)
Indeed, the name 'saponin' comes from the Latin word
Saponins are constituents of many plant drugs and folk medicines, especially from the Orient.
Consequently, great interest has been shown in their characterization and in the investigation of their pharmacological and biological properties
The most common sources of saponins are the higher plants, but increasing numbers are being found in lower marine animals. So far, they have only been found in marine phylum Echinodermata and particularly in species of the classes Holothuroidea(sea cucumbers) and Asteriodea (starfishes)
The aglycon or non-saccharide portion of the saponin molecule is called the genin or sapogenin. Depending on the type of genin present, the saponins can be divided into three major classes:
Steroid alkaloid glycosides
All saponins have in common the attachment of one or more sugar chains to the aglycone.
saponins have a single sugar chain normally attached at C-3. Bidesmosidic saponins have two sugar chains and tridesmosidic have three sugar chain. Tridesmosidic saponins are seldom found.
Bidesmosidic saponins are easily transformed into monodesmosidic saponins by, for example, hydrolysis of the esterified sugar at C-28 in triterpene saponins; they
many of the characteristic properties and activities of monodemosidic saponins.
The saccharide moiety may be linear or branched, wtih 11 being the highest number of monosaccharide units yet found in a saponin. As a rule, however, most of the saponins so far isolated tend to have relatively short sugar chains, containing 2-5 monosaccharide residues.
The most common monosaccharide moietes found are:
D glucuronic acid
D galacturonic acid
Saponins are extremely widely distributed in the plant kingdom. Even by 1927, Kofler had listed 472 saponin containing plants and it's known that
over 90 families contain saponins.
Gubanov (1970) found, in a systematic investigation 1730 central asian plant species, that %76 of the families contained saponins.
Saponins occur in plants which are used as human food: soybeans, chick peas, peanuts, mung beans, asparagus, garlic, peppers, potatoes, tea and leguminous forege species
Saponin content depends on factors such as the cultivar, the age, the physiological state and geographical location of the plant.
The saponin distrubition among the organs of a plant varies considerably. In the garden marigold (Calendula officinalis, Asteraceae), for example, saponins with a glucuronic acid moiety at C-3 oleanolic acid are found in the flowers, while a glucose moiety at the same position is found in the saponins from the roots. The flowers contain %3.57 and roots contain %2.59 of their dry weight in the form of saponins
The widespread occurence of saponins has meant that an awereness of these glycosidic plant constituents and their
effect existed for centuries.
The list of biological activities associated with saponins is very long.
New activities are continually being discovered. Antisweetness and utero-contraction are just two of these.
1- Fungicidal Activity
Numerous early examples of antifungal saponins exist in the literature.
The strongest activities are exhibited by the monodesmosidic saponins. Shorter carbohydrate chains lead to lower water solubility and weaker antifungal activity.
Saponins are specially very effective to plant pathogenic fungus.
Although strongly antifungal activity,
triterpene glycosides have virtually no antibacterial activity. Some are weakly active againist the gram positive bacteria but show no effect on gram negative bacteria.
Glycyrrhizin inhibits the growth of several DNA and RNA viruses but has no effect on protein synthesis and replication of uninfected cells. Herpes simplex virus particles are also irreversibly inactivated and antiviral action againist varicella-zoster virus has been documented.
Saponins Chemistry and Pharmacology of Natural Products K. Hostettmann, A. Marston Cambridge University Press, 2005