Efficient discovery of active isolates from Dioscorea spongiosa by the combination of bioassay-guided macroporous resin column chromatography and high-speed counter-current chromatography

In the present study, twelve compounds from Dioscorea spongiosa were successfully purified by an efficient technique combined bioassay-guided fractionation macroporous resin column chromatography (MRCC) pretreatment and high-speed counter-current chromatography (HSCCC) separation for the first time. Then, D101 MRCC was used to fractionate the crude extract into five parts, which further applied the bioassay-guided fractionation strategy to screen the active fractions of 2 and 4. As for the separation, 200 mg Fr.2 was purified by HSCCC using EtOAc/ n -BuOH/H 2 O (2:2:3, v/v), leading to annulatomarin ( 1 ), dioscoresides C ( 2 ), diosniponol C ( 3 ), methyl protodioscin ( 4 ), pseudoprotodioscin ( 5 ), protogracillin ( 6 ), as well as 200 mg Fr.4 yielding montroumarin ( 7 ), dioscorone A ( 8 ), diosniponol D ( 9 ), protodioscin ( 10 ), gracillin ( 11 ), and dioscin ( 12 ) using CH 2 Cl 2 /MeOH/H 2 O (3:3:2, v/v) with the purities over 95.0%. Finally, the isolates were assayed for their anti-inflammatory, urico-lowering, and anti-diabetic activities in vitro, which indicated that the steroidal saponins of 5 , 6 , and 11 showed all these three activities.