Saponin Subject

Saponins for beverage use are sourced from quillaia bark (Quillaia saponaria Molina) and the yuccas. Of the latter species, two main varieties are used in the United States for production of the water extract the Mohave yucca (Yucca mohavensis) and the Joshua tree (Yucca brevifolia). At the levels used these additives are colourless and tasteless the dried extract, however, possesses an acrid, astringent taste. Permitted limits are quoted in terms of the dry weight of the extract. In the European Union, subject to Directive 95/2/EC, quillaia is permitted only in non-alcoholic drinks, to a maximum level of 200 mg/1. 

Many compounds can act as adjuvants. Their classification is made difficult by the variety in chemical composition and the overlapping, often poorly understood, mechanisms of action. Only aluminum adjuvants are approved by the FDA for use in human vaccines. Quil A is a saponin that is commonly used as an adjuvant in veterinary vaccines and is also a component of immune-stimulating complexes (ISCOM). These adjuvants are addressed in some detail below. A detailed discussion of other types of adjuvants can be found in recent books and reviews on this subject. 

It is well known that dietary fat is not absorbed from the intestine unless it has been subjected to the action of pancreatic lipase [1], Previously, we found that basic proteins such as protamines, histones and purothionine inhibited the hydrolysis of triolein emulsified with phosphatidylcholine [2], The inhibition of hydrolysis of dietary fat may cause a decrease or delay in the intestinal absorption of fat and reduce blood chylomicron levels, an excess of which is known to induce obesity [3], Therefore, there was a possibility that inhibitory substances toward pancreatic lipase activity may prevent the onset of obesity induced by feeding a high fat diet to mice. Recently, we found that natural products such as tea saponin, platycodi radix saponin, chitin-chitosan and chondroitin sulfate inhibited the pancreatic lipase activity. In the following section, the anti-obesity effects of these natural products will be described in detail. 

In our study the butanol-soluble fraction was proved to be effective for terminating pregnancy in rats. The results agreed with literature reports and suggested the active principles should be hydrophilic components. However, some soponins we subjected to test showed not effective and the water eluent on a highly porous polymer chromatography seems much better than individual saponin in animal test. The experiments should be repeated and confirmed to make a conclusion carefully. 

Acetylation of saponins. To each saponin (5mg) was added Ac20-pyridine (1 1) (0.5ml) in a microtube. After standing at room temperature for 48 hrs, the soln was evapd to dryness and then subjected to EIMS analysis. 

It followed that the same epimerization probably occurred during acid hydrolysis of the Ginseng saponins. The chloro compound (10) was obtained from the ether insoluble fraction of the crude hydrolysate of the saponin mixture with cone. HCl. The ether soluble fraction of the hydrolysate was subjected to dehydrochlorination to give an 20-epimer of (11) named 20(S)-protopanaxadiol (26) (Chart 2), the structure of which was elucidated by correlating it with (13) as follows. The dihydro derivative (27) of (26) was oxidized to give a diketone (28) which was identical with the diketone derived from (13) via (16) 16, 17, 19). Crystalline substances (1) and (12) of the 20(R)-series were also readily obtained from the less soluble fractions of the hydrolysates of the saponin mixture and from the hydrogenated saponin mixture, respectively, while the corresponding 20 ( S)... 

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