Dammarane sapogenins structure

II. Structure and Chemistry of Dammarane Sapogenins 1. Panaxadiol, an Artifact... 

Sapogenins of the dammaran type were isolated from the leaves and roots of the plant Panax no-toginseng, native to China One of these sapogenins has the elemental composition C3o/f5204 and produces the set of NMR results 51. What is the structure of the sapogenin ... 

Since 1958, Shibata and his successors have conducted chemical studies on the saponins of the crude drug. After many twists and turns, it was determined that the major saponins of Ginseng were not oleanane oligoglycosides which are very common in nature, but that the genuine sapogenins were represented by triterpenes of the dammarane type. This was the first example of the occurrence of dammarane saponins in nature. The complications encountered in the isolation and structure determination were mainly due to an unexpected acid catalyzed epimerization of the tertiary hydroxyl group on c-20 of the carbon skeleton which was followed by cyclization of the side chain. This undesirable reaction accompanied acid hydrolysis of the saponins to the sapogenins. 

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