Saponins purification

Avenacinase, an enzyme from G. graminis var. avenae, is related to tomatinase from S. lycopersici because is able to deglucosilate tomatine by identical mode of action. However, the activity is very low and corresponds to approximately 2% of its activity towards avenacin A-1 [32]. Tomatinase form S. lycopersici, also can cleave avenacin A-l but has less than 0.01% of activity towards it in comparison to its activity towards tomatine [32]. Therefore, the two enzymes are highly specific for their respective host plant saponins. Purification and characterization of S. lycopersici tomatinase revealed that this enzyme shares many properties (including immunological cross-reactivity) with avenacinase... 

Saponins. Although the hypocholesterolemic activity of saponins has been known since the 1950s, thek low potency and difficult purification sparked Htde interest in natural saponins as hypolipidemic agents. Synthetic steroids (292, 293) that are structurally related to saponins have been shown to lower plasma cholesterol in a variety of different species (252). Steroid (292) is designated CP-88,818 [99759-19-0]. The hypocholesterolemic agent CP-148,623 [150332-35-7] (293) is not absorbed into the systemic ckculation and does not inhibit enzymes involved in cholesterol synthesis, release, or uptake. Rather, (293) specifically inhibits cholesterol absorption into the intestinal mucosa (253). As of late 1996, CP-148,623 is in clinical trials as an agent that lowers blood concentrations of cholesterol (254). 

Direct injection API-Electrospray MS is capable of analyzing much larger and less volatile substances than either EI/MS or CI/MS. As a result, this method is often used to provide structural information on peptides, proteins, and polymers derived from both natural and synthetic processes it is also useful in the analysis of many natural compounds including molecules such as saponins and flavonol glycosides, derived from plants. When using direct injection API-electrospray, partial purification and EC preparation are performed elsewhere and a collected fraction is dissolved in an appropriate solvent and injected as a bolus into the mass spectrometer (flow or direct injection or syringe infusion). This has an advantage, as the mass... 

A typical isolation strategy is the preliminary purification of the n-butanol extract over dextran supports like Sephadex LH20 or Fractogel TSK, followed by further fractionation of the crude saponin mixtures [111]. A new generation of polymers has been exploited for the initial purification steps. They are highly porous polymers (Daion HP-20, MCI gel CHP-20P (both from Mitsubishi Chemical Industries, Tokyo), Amberlite XAD-2) [112], Methanol-water or acetone-water solvent gradients are used. 

Benichou, A., Aserin, A., and Garti, N. 1999. Steroid-saponins from fenugreek seeds extraction, purification and surface properties. J. Dispers. Sci. Technol. 20, 581—605. 

Petit, P.R., Sauvaire, Y.D., Hillaire-Buys, D.M., Leconte, O.M., Baissac, Y.G., Ponsin, G.R. and Ribes, G.R. (1995) Steroid saponins from fenugreek seeds extraction, purification, and pharmacological investigation on feeding behavior and plasma cholesterol. Steroids 60(1 0), 674-680. 

Steroidal saponins are usually highly polar compounds occurring as complex mixtures, and their separation into individual components is a formidable task. The traditional purification and separation process for... 

Another class of compound that can be difficult to purify is the saponins found in Echinoderms. Almost all echinoderms examined to date contain either polyhydroxylated sterols or terpene glycosides, many of which contain sulfate ester functionality. The purification of compounds (Schemes 6-9) (40) from the starfish Nardoa tuberculata exemplifies the procedure most often used to purify these metabolites (Fig. 2). 

The last review on the Caryophyllaceae family was published almost two decades ago [1]. Since then, purification and structural elucidation techniques have changed enormously. Many of the earlier chemical studies have been reinvestigated and new findings published. The present review deals with the chemistry of the triterpenoid saponins of Caryophyllaceae family with special emphasis on recent developments in purification techniques and structural study aspects. 

The MeOH extract of the freshly collected whole plant of S. officinalis was suspended in water and partitioned successively with EtOAc and n-BuOH. The aqueous part, on chromatography over Diaion HP-20 followed by repeated MPLC and HPLC purification afforded two major triterpenoid saponins, saponariosides A and B. Similarly, the -BuOH soluble fraction afforded six triterpenoid saponins designated as saponariosides C-H. Investigation of the plant material collected from different geographical locations led to the isolation of previously reported saponariosides C, E, F and G along with five more new saponins, saponariosides I-M (Fig. 7), from which two new sapogenins have been characterized as VIII and XII (Fig. 1). However, saponarioside D, the major constituent of the -BuOH soluble fraction as reported previously by us [21], could not be detected. 

Key Word Index allelochemical activity, bioassay, continuous cropping, epicotyl, extraction, inhibitory, lettuce, life cycle, mass spectrometry, mono and bi-desmoside saponins, mungbeans, purification, radicle, soyasaponins, soil, stimulation, thin layer chromatography, Vigna radiatu L., Lactuca sativa L. 

Saponins Isolated from Plants Grown in the Field. The crude saponins (Fig. 3) were isolated from each part of the plant. For all of the data report on TLC, HPLC, MS, and bioassay the saponins were processed through the first stage of purification, which was extracted with 1-butanol. Leaf biosynthesis of crude saponins (Fig. 3) occurred in 3 bursts at approximately 30-50, 55-65, and 75-90 days, which corresponded to the initiation of flowers, leaf development, and maturity. The total saponins accumulated corresponds to 1.8 g saponins/plant however, in the purification with 1-butanol about 40% of the crude saponins were lost leaving about 1 g saponins/plant being produced during the life cycle. The stems were relatively constant at around 20-30 mg saponins/plant after 30-40 days of age the roots were similar in content to the leaves in that at 30-40 days of age they increased from 20 mg/plant to 70-80 mg/plant which corresponded with the second and third trifoliate leaf development. This burst of biosynthetic activity of saponins coincides with the onset of fungal root disease which was identified earlier as due to Rhizoctonia spp, Pythium spp, and Fusarium spp (8,9, 15-17). 

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