Purple bergenia element pentaacetylate and its uses

The invention provides a Bergenini penta-acetyl, whose chemical name is (2R,3R,4R,4aS,10bS)-2-(acetoxymethyl)-9-methoxy-6-oxo-2,3,4,4a,6,10b-hexahydr o pyrano[3,2-c]isochromene-3,4,8,10-tetrayl tetraacetate, and is prepared from Bergenini as lead compound through butanoylation reaction, the hydroxyl on the precursor is blocked so as to enhance the lipophilicity. The Bergenini penta-acetyl can be used for preparing medicine for relieving cough. The invention further provides a compound preparation containing the Bergenini penta-acetyl.