The dried rhizomes (205 g) of DZW were extracted with EtOH,
and the EtOH was evaporated with a rotary evaporator system
(BÜCHI, Switzerland) to give a sugar-shaped crude product. The
crude product (41 g) was suspended in a water solution (500 ml),
and two individual phases were obtained, a water-soluble part
and a water-insoluble part (WIP). The WIP was freeze-dried to give
a dry powder (WIP, 10.8 g). The water-soluble part was further
partitioned by petroleum, EtOAc and n-BuOH, successively. These
partitions were each concentrated to obtain the final products of
a petroleum-soluble phase (PP, 1.4 g),