A minor lignin,4-demethyldeoxypodophyllotoxin,was isolated from Sinopodophyllum emodi.First,a crude extract of Sinopodophyllum emodi was analyzed by HPLC-MS to confirm the presence of the target compound.Then,the target lignin was successfully enriched in the crude extract precipitate by medium-pressure LC with high recovery(85%).Finally,an efficient separation was achieved by high-speed counter-current chromatographyusing a two-phase solvent system of n-hexane-ethyl acetate-methanol-water(1:1:1:1,v/v/v/v).These results clearly demonstrate that the combination of HPLC-MS,medium pressure LC and high-speed counter-current chromatography could be a powerful technique for the rapid screening,enrichment and separation of minor compounds from complex natural products.