An efficient strategy for large‐scale preparation of low polarity gingerols directly from ginger crude extract by high‐speed countercurrent chromatography with different rotation mode

This study presents an efficient strategy for large‐scale preparation of low polarity gingerols directly from ginger crude extract by high‐speed countercurrent chromatography with different rotation mode. The ultrasonic‐assisted extraction conditions were optimized by response surface methodology and the results showed the major low polarity gingerols could be well enriched under the optimized extraction conditions. Then the crude extract without any pretreatment was directly separated by high‐speed countercurrent chromatography with different rotation mode using n‐hexane/ethyl acetate/methanol/water (6:4:6:4, v/v/v/v) as the solvent system. In about 400 min, five major gingerols including 150 mg of [6]‐gingerol, 50 mg of [8]‐gingerol, 20 mg of [6]‐shogaol, 43 mg of [6]‐dehydrogingerdione, and 40 mg of [10]‐gingerol were obtained from 1.2 g of crude extract in a single run with repeated injection. Their structures were identified by 1 H‐NMR spectroscopy.