Neutral Triterpenes

One recognises among the variety of solvent systems which have so far been used for chromatographic separation of the neutral C30-derivatives, that here too, benzene, chloroform or diisopropyl ether have had preference as major solvent components (Table 34). 

Only non-polar hydrocarbons like squalene [124] or /3-amyrene migrate on silica gel layers when n-hexane is used. Separation of comic Thin Layer Chromatography, 2nd Edition 

If the number and position of the double bonds in the substances studied, differ, their silver nitrate-complexes can often be separated 

Petrol ether-ethyl acetate (95 + 5) Petrol ether-ether (90 + 10) 

Arburinol Aescin, aescinidin etc. Gypsogenin (hi / 25) Gypsogenin lactone (hi / 85) Triterpenes from- Lycopodium Triterpene lactones 

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P. Monaco, R. Caputo, G. Palumbo, L. Mangoni, Neutral triterpenes from the galls of Pistacia terebinthus, Phytochemistry, 12, 939 942 (1973). 

Palrrma intermedia Valeri anaceae USSR roots +STN acidic and neutral triterpene glycosides 142... 

The various teams [19, 125, 128, 135, 191, 245, 256, 290, 319] have used mostly aqueous-alcoholic mobile phases hke, for example, chloro-form-methanol-water (65 + 35 -f 10) for separation of mixtures of neutral triterpene glycosides. The ethyl acetate-carbon tetrachloride mixtures which Linde [150] has employed for separation of Cimicifuga glycosides, are less polar (cf. also [35, 36]). 

Lipases liberated from the testa and the cross cells promote rapid hydrolysis of the oil, and therefore, it should be extracted within hours of milling. Attempts have been made to upgrade oil with 30% free acid by reaction with glycerol and the enzyme Lipozyme Mucor miehei lipase) followed by neutralization. The major acids in rice bran oil are palmitic (12-18%, typically 16%) oleic (40-50%, typically 42%), and linoleic acid (29 2%, typically 37%). The oil contains phospholipids ( 5%), a wax that may be removed and finds industrial use, and unsaponifiable matter including sterols, 4-methylsterols, triterpene alcohols, tocopherols, and squalene among others. 

A native of Europe and the northwest coast of Africa, various flavonoids and triterpenes are the most active ingredients. Strong immune stimulating properties signal the treatment of cancer patients with weak immune systems. Studies show a capability to neutralize the West Nile virus. Also called elderbeny. 

Mills, J. S. The Constitution of the Neutral Tetracyclic Triterpenes of Dammar Resin. J. Chem. Soc. (London) 1956, 2196. 

There seems little point in subdividing the triterpenes into classes according to polarity, as done with the 10 -derivatives. With a view to preliminary separation of the substances during isolation, a division into neutral and acid triterpene derivatives is to be recommended. The hydrophilic triterpene glycosides can then profitably be separated from these ( bitter principles and saponins ). 

Neutral and acid triterpenes have been treated in the two preceding sections. These compounds can also be combined in glycosides. One may therefore expect that neutral and acid glycosides will occur in nature, all the more so because uronic acids are not excluded as sugar components. Chromatographic investigations should be aimed in this direction. 

Two classes are recognized, the so-called neutral saponins (digitalis saponins), which have as aglycons substances derived from cyclopentano-perhydrophenanthrene, and the acid saponins, which have as aglycons substances derived from triterpene. The aglycons are called sapogenins. Most of the investigations have been devoted to the determination of the structures of the neutral saponins. 

Finally, besides polar lipids, the bacteria membranes contain neutral lipids, analogous to sterols in eucaryotes. These triterpenic and pentacyclic molecules are called hapanoids. They are formed by the cyclization of squalene in an anaerobic process. They have not been clearly identified in lactic acid bacteria. 

Kikuchi, T., M. Takayama, T. Toyoda, M. Arimoto, and M. Niwa Studies on the Neutral Constituents of Pachysandra terminalis Sieb. et Zucc. V. Structures of Pachysandiol-B and Pachysonol, New Friedelin Type Triterpenes. Chem. Pharm. Bull. (Japan) 21, 2243(1973). 

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