| 摘要 |
NEW MATERIAL:The compound of formula {R<1> is[beta-glucopyranosyl (1 2)-]beta- glucopyranosyl or[beta-glucopyranosyl(1 2)-]alpha-arabinopyranosyl-H; R<2> is CH2OH or CHO; R<3> is[beta-xylopyranosyl(1 6)-beta-]glucopyranosyl or OH; R<4> is beta-glucopyranosyloxymethyl, OH or CH3}. EXAMPLE:19,20xsi-Dihydroxy-3-O-[beta-glucopyranosyl(1 2 )-beta-glucopyranosyl]-21- O-beta-glucopyranosyl-dammar-24-ene (gypenoside XXIII). USE:Antiulcer agent (for digenstive tracts). PROCESS:The overground part of AMACHAZURU (Gynostemma pentaphyllum Makino, grown in the Hyogo prefecture, Japan) is collected and extracted with hot water. The pale yellowish brown extract is treated with ion exchange resin and alumina column to obtain the yellow powder of total saponin fraction. The fraction is fractionated by silica gel column to obtain each fraction of gypenoside. The obtained fraction can be converted to another type of gypenoside by enzymatic decomposition. |
