Gypsophila paniculata saponins have been used for a long time under the generic name of saponin. They have the typical properties of saponins, such as detergent, emulsive, hemolytic, and membrane-toxic substances. Research has been carried out in various biological fields, for example in studies on virus (Rous sarcoma virus), on cell membranes (of chicken liver and erythrocyte ghosts) (), in the preparation of vaccines to enhance the immune response (Freund’s adjuvent), or for use as a commercial product, known as Saponin pure white (Merck). This product has also been widely employed as a standard for hemolytic tests in most saponin determinations, and was previously reported to be extracted from roots and rhizomes of Gypsophila paniculata (). These Gypsophila paniculata saponins, as well as digitonin, have been studied for their water insoluble complexes with cholesterol ().
Distribution and Importance of the Genus Gypsophila
The genus Gypsophila (from the Greek gypsos: gypsum, calc, and philos: friend) contains 125 species native to the temperate regions of Eurasia (21 species in Europe), living on old walls or on gypseous ground (). A few of them are encountered in Egypt, Australia, and one species in New Zealand, probably introduced (). Among these various species, only a few are of commercial interest, for example, Gypsophila elegans M. Bieb. (found from Ukraine to Iran) and Gypsophila paniculata (baby’s breath), found from Central Europe to Central Asia are the species most often planted for their medicinal and ornamental interest. The latter species is used for wedding bouquets ().Gypsophila patrini Ser. is used as a copper indicator in Russia, Gypsophila struthium Loefl. as soap in the Mediterranean Basin and Gypsophila rokejeka Del. (found in Egypt and the eastern Mediterranean Basin) in halva with sesame seeds and honey (). This chapter describes work on Gypsophila paniculata L.
Gypsophila paniculata is well known to contain saponins with various applications of commercial interest. They are used for the composition of photosensitive surfaces in photography, and of shampoos (). More recently, these saponins were described as being apparently responsible for spermicidal and antiinflammatory effects ().
The Plant: Gypsophila paniculata
Gypsophila paniculata L. (baby’s breath) () is a perennial plant belonging to the family Caryophyllaceae. It is a herb which can reach 1.50 m in height, the most important part being underground. The roots are ramified with long, thick branches. The upper shoot is erect, with leaves reduced to an enlarged and flattened petiole. The elongate bipartite cymes contain many small (2-4 mm), closely gathered, white or pink flowers, which are composed of a short calyx (2 mm) split almost to the bottom. Flowering occurs in July and August ().
Saponins of Gypsophila paniculata
Gypsogenin () is the main pentacyclic triterpenoidal aglycone of these saponins and was described many years ago (). Substituted on the OH 3 and on the COOH 28 by two chains of different glycosides, these saponins, called bidesmosidic, are among the highest glycosylated. A saponin called gypsoside () was first extracted from G. pacifica (), and found next in G. paniculata (). This saponin, containing nine glycosides, appears to be the same as the “gypsophila saponin” first described by Van der Haar (1927). However, these highly glycosated saponins break easily during extraction and purification and give shorter saponins. These previous structural determinations of Gypsophila saponins must be studied carefully, because the difficulties of these first chemical studies do not detract from the great merit of these first saponin chemists.
Gypsophila paniculata was shown to synthesize gypsogenin saponins, both in undifferen-tiated callus and multiple shoot cultures. The other species studied either became inconsistent in producing these saponins (Gypsophila petraea) or lost the biosynthetic potential after several subcultures (Gypsophila repens). Such differing biosynthetic behavior may be a model for comparative studies on the regulation of saponin biosynthesis, to enhance saponin production.
From the developmental aspect, the gypsogenin 3,O-glucuronide biosynthesis present in both undifferentiated callus and multiple shoot cultures of Gypsophila paniculata is all the more surprising as, in the vegetative state of the mature plant, only the roots contain gypsogenin saponins (7.5 mg/g dry weight in 1-year-old plants to 40 mg/g dry weight in 4-year-old plants), and the other parts of the plant are not able to produce any.
Selections from the book: “Medicinal and Aromatic Plants IV”, 1993.