pH-gradient counter-current chromatography isolation of natural antioxidant chlorogenic acid from Lonicera japonica Thumb. using an upright coil planet centrifuge with three multi-layer coils connected in series.

pH-gradient counter-current chromatography isolation of natural antioxidant chlorogenic acid from Lonicera japonica Thumb. using an upright coil planet centrifuge with three multi-layer coils connected in series.