Elution–extrusion counter-current chromatography separation of five bioactive compounds from Dendrobium chrysototxum Lindl

Full use of the liquid nature of the stationary phase: The development of elution‐extrusion counter current chromatography

“…Berthod et al [9] revised this method and proposed an extended theoretical treatment, providing equations for solute retention volumes, peak widths, resolution factors, and selectivity. After more than 10 years of development, Li et al [16] theoretically developed the calculation strategy of time. And they proposed a calculation equation for the system to calculate the extraction time point of extract.…”

Elution–extrusion countercurrent chromatography separation of six pairs of isomeric iridoids from Cornus officinalis Sieb. et Zucc. guided by ion current extraction in mass spectrometry

“…As an alternative to the classical gel chromatographic techniques, CCC has proven to be efficient in the separation of natural products of health interest . Employing the liquid nature of the stationary phase, elution–extrusion countercurrent chromatography (EECCC) extends the hydrophobicity window of any single biphasic solvent system in CCC separation to all compositions with distribution constants ( K C ) ranging from zero to infinity in one run . To represent K C values corresponding to each eluted peak, special chromatographic patterns with an x ‐axis graduated in a complete range of K C values (0–∞) have been proposed as reciprocal shifted symmetry (ReSS) plots .…”

Elution‐extrusion Counter‐current Chromatography Separation of Two New Benzyl Ester Glucosides and Three Other High‐polarity Compounds from the Tubers of Pleione bulbocodioides

“…Further, Berthod et al . () developed elution‐extrusion counter‐current chromatography (EECCC) that combined normal elution and extrusion in a single run with the advantages of reducing the separation time and solvent consumption, and that has been widely used in natural products separation in recent years (Li et al ., ). Although, many solvent systems have been reported for the separation of high‐polarity compounds using CCC, such as chloroform:methanol:isopropanol:water (Yoon et al ., ), acetate:methanol:water (Xie et al ., ) and n ‐butanol:methanol:chloroform:water (Wang et al ., ), none of them was suitable for the separation of gastrodin and benzyl ester glucosides, which possessed much higher polarity.…”

“…Compared with the conventional methods of column chromatography, counter-current chromatography (CCC), a support-free chromatographic technique described by Ito (2005), manages to eliminate irreversible adsorption of the sample onto the solid support and enables the direct application of crude extracts (Ito, 2005;Cheng et al, 2012;Jia et al, 2012;Wu et al, 2012;Xiao et al, 2012;Xu et al, 2012). Further, Berthod et al (2003) developed elution-extrusion counter-current chromatography (EECCC) that combined normal elution and extrusion in a single run with the advantages of reducing the separation time and solvent consumption, and that has been widely used in natural products separation in recent years (Li et al, 2011). Although, many solvent systems have been reported for the separation of high-polarity compounds using CCC, such as chloroform: methanol:isopropanol:water (Yoon et al, 2012), acetate:methanol:water (Xie et al, 2010) and n-butanol:methanol:chloroform: water , none of them was suitable for the separation of gastrodin and benzyl ester glucosides, which possessed much higher polarity.…”