Preparative separation of gingerols from Zingiber officinale by high-speed counter-current chromatography using stepwise elution

Following an initial clean-up step on silica column, high-speed counter-current chromatography (HSCCC) was used to purify gingerols from an extract of the dried rhizome of Zingiber officinale. The sample was separated with petroleum ether–ethyl acetate–methanol–water (1:0.2:0.5:0.7, v/v) and petroleum ether–ethyl acetate–methanol–water (1:0.2:0.7:0.5, v/v) in a stepwise elution and yielded 132 mg of 6-gingerol, 31 mg of 8-gingerol and 61 mg of 10-gingerol from 360 mg of pre-purified sample. The purity of each compound was over 98% as determined by HPLC. The structures of the three compounds have been identified by LC-ESI-MS, 1H NMR and 13C NMR.