Acylated Protopanaxadiol‐Type Ginsenosides from the Root of Panax ginseng

Abstract Six new protopanaxadiol‐type ginsenosides, named ginsenosides Ra 4 –Ra 9 ( 1 – 6 , resp.), along with 14 known dammarane‐type triterpene saponins, were isolated from the root of Panax ginseng , one of the most important Chinese medicinal herbs. The structures of the new compounds were determined by spectroscopic methods, including 1D‐ and 2D‐NMR, HR‐MS, and chemical transformation as (20 S )‐ 3‐ O ‐{ β ‐ D ‐6‐ O ‐[( E )‐but‐2‐enoyl]glucopyranosyl‐(1→2)‐ β ‐ D ‐glucopyranosyl}‐20‐ O ‐[ β ‐ D ‐xylopyranosyl‐(1→4)‐ α ‐ L ‐arabinopyranosyl‐(1→6)‐ β ‐ D ‐glucopyranosyl]protopanaxadiol ( 1 ), (20 S )‐3‐ O ‐[ β ‐ D ‐6‐ O ‐acetylglucopyranosyl‐(1→2)‐ β ‐ D ‐glucopyranosyl]‐20‐ O ‐[ β ‐ D ‐xylopyranosyl‐(1→4)‐ α ‐ L ‐arabinopyranosyl‐(1→6)‐ β ‐ D ‐glucopyranosyl]protopanaxadiol ( 2 ), (20 S )‐3‐ O ‐{ β ‐ D ‐6‐ O ‐[( E )‐but‐2‐enoyl]glucopyranosyl‐(1→2)‐ β ‐ D ‐glucopyranosyl}‐20‐ O ‐[ β ‐ D ‐glucopyranosyl‐(1→6)‐ β ‐ D ‐glucopyranosyl]protopanaxadiol ( 3 ), (20 S )‐3‐ O ‐{ β ‐ D ‐6‐ O ‐[( E )‐but‐2‐enoyl]glucopyranosyl‐(1→2)‐ β ‐ D ‐glucopyranosyl}‐20‐ O ‐[ α ‐ L ‐arabinopyranosyl‐(1→6)‐ β ‐ D ‐glucopyranosyl]protopanaxadiol ( 4 ), (20 S )‐3‐ O ‐{ β ‐ D ‐4‐ O ‐[( E )‐but‐2‐enoyl]glucopyranosyl‐(1→2)‐ β ‐ D ‐glucopyranosyl}‐20‐ O ‐[ α ‐ L ‐arabinofuranosyl‐(1→6)‐ β ‐ D ‐glucopyranosyl]protopanaxadiol ( 5 ), (20 S )‐3‐ O ‐{ β ‐ D ‐6‐ O ‐[( E )‐but‐2‐enoyl]glucopyranosyl‐(1→2)‐ β ‐ D ‐glucopyranosyl}‐20‐ O ‐[ α ‐ L ‐arabinofuranosyl‐(1→6)‐ β ‐ D ‐glucopyranosyl]protopanaxadiol ( 6 ). The sugar moiety at C(3) of the aglycone of each new ginsenoside is butenoylated or acetylated.