Large-scale preparative isolation of bergenin standard substance from Saxifraga atrata using polyamide coupled with MCI GEL® CHP20P as stationary phases in medium pressure chromatography

•Novel polyamide coupled with MCI GEL® CHP20P MPC was employed for the preparative separation of bergenin from Saxifraga atrata.•Polyamide MPC was successfully used in enrichment of bergenin target fraction.•MCI GEL® CHP20P MPC was perfectly used in solving purification of bergenin from the target fraction.•The bergenin with >99% purity was isolated from Saxifraga atrata for the first time. In this study, polyamide and MCI GEL® CHP20P were employed as stationary phases in medium pressure chromatography (MPC) for the efficient preparative separation of bergenin from Saxifraga atrata. Ethanol–water, methanol-water, and acetonitrile-water mobile phases all showed good enrichment capacity for bergenin fraction when polyamide was used as a stationary phase. After 5 cycles of polyamide MPC using acetonitrile/water, 1.2 g of bergenin fraction was isolated from 180 g Saxifraga atrata herb. Further purification of this fraction was conducted using MCI GEL® CHP20P styrene-divinylbenzene beads. The bergenin fraction was separated into two fractions, and after three runs of MPC, 714.2 mg of bergenin with purity above 99% was obtained. The results demonstrate that the combination of polyamide and styrene-divinylbenzene MPC can be utilized for preparative isolation of compounds from natural products with high yield and purity.