Aminosteroids, Steroid Alkaloids and Glycosides

Compounds like those with the structures given below are considered here  

The Solanum glycosides, for example, have the following compositions  

The C25-isomers of the Solanum alkaloids are easier to separate than the corresponding isomers of the sapogenins. 

As far as the glycosides themselves are concerned, partition systems come into consideration, as with the saponins bases or acids may sometimes be added. Successful fractionation into groups has been achieved on silica gel, using, for example, acetic acid-95 % ethanol 

The isomers with the 6-ring nitrogen in a-position on C22 are more polar than those with the )S-configuration. 

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