Studies on the Constituents of Japanese and Chinese Crude Drugs. XI. Panaxadiol, A Sapogenin of Ginseng Roots. (1).

Abstract

Panaxadiol, C30H52O3, a sapogenin of Ginseng roots was acetylated to afford monoacetate, C32H54O4, which was oxidized with chromium trioxide to give panaxanolone acetate, C52H52O4. On Wolff-Kishner reduction, panaxanolone acetate was converted into panaxanol, C30H52O2, which was heated with hydrochloric acid in glacial acetic acid to furnish anhydropanaxanol acetate, C32H52O2. On catalytic hydrogenation of anhydropanaxanol, isotirucallenol (X) was obtained, which was established by infrared and gaschromatography. A trimethyltetrahydropyrane ring system in panaxadiol was proved by mass-spectrometry, and the oxygen ring was cleaved by the action of hydrochloric acid on panaxanol. The α, β-unsaturated ketonic system was proved ultraviolet spectroscopically in the product derived from panaxanolone acetate by the action of sulfuric acid in glacial acetic acid. Thus the hindered hydroxyl of panaxadiol should be present at the 12-position. Consequently, it has been concluded that panaxadiol is a new tetracyclic triterpene of dammarane series having hydroxyls at the 3- and 12-positions and trimethyltetrahydropyrane ring at C(17), as represented by the formula (T).