Centrifugal countercurrent chromatography,

The dichloromethane soluble extracts were permeated through Sephadex LH-20 (CH2CL2-MeOH, 1 1, v/v). Centrifugal countercurrent chromatography as described above yielded compounds 5, 6, and 7. Table I summarizes the isolation scheme for diketopiperazines 1-7. 

Figure 11-2. Components needed for centrifugal countercurrent chromatography.

Abbott, T, Peterson, R., McAlpine, J., Tjarks, L., and Bagby, M. (1989) Comparing centrifugal countercurrent chromatography, nonaqueous reversed phase HPLC and Ag ion exchange HPLC for the separation and characterization of triterpene acetates. J. Liquid Chromatogr. 12, 2281-2301. 

Like solvent extraction, separations by extraction chromatography and centrifugal partition chromatography (also known as centrifugal countercurrent chromatography depending on the apparatus used), are based on the partitioning of an analyte between... 

Zhang, T.Y. et al.. Separation of flavonoids in crude extract from sea buckthorn by countercurrent chromatography with two types of coil planet centrifuge, J. Liq. Chromatogr., 11, 233, 1988. 

Countercurrent Chromatography Countercurrent chromatography (CCC) or centrifugal partition chromatography (CPC) has gained much attention in recent years for isolation of polyunsaturated fatty acids. This new liquid chromatographic technique uses liquid-liquid partition, countercurrent distribution of solute mixmre between two liquid phases, in the absence of a solid support, to perform separation of complex mixture of chemical substances (44, 45). 

Open-column chromatography with silica gel and alumina is not applicable to the fractionation of tanins because of their strong binding to these adsorbents, which induces extensive loss of tannins. Such losses do not occur with countercurrent chromatography, as it does not use a solid stationary phase. Such molecules are very polar, so butanol-based solvent systems can be used. Centrifugal partition chromatography is more adequate in this case, as compared to hydrodynamic CCC, because of the good retention of the stationary phase of a such solvent system. 

Ito, Y. Oka, H. Slemp, J.L. Improved cross-axis synchronous flow-through coil planet centrifuge for performing countercurrent chromatography. I. Design of the apparatus and analysis of acceleration. J. Chromatogr. 1989, 463, 305-316. 

Ito, Y. Menet, J.-M. Coil Planet Centrifuges for High-Speed Countercurrent Chromatography. In Countercurrent Chromatography Menet, J.-M., Thiebaut, D., Eds. Marcel Dekker New York, 1999 87-119. 

The effects of the Coriolis force on countercurrent chromatography have been demonstrated on the toroidal coil centrifuge which uses a coiled tube mounted around the periphery of the centrifuge bowl [2]. When a protein mixture containing cytochrome-c. 

Shibusawa, Y. Ito, Y. Countercurrent chromatography of proteins with polyethylene glycol-dextran polymer phase systems using type-XLLL cross-axis coil planet centrifuge. J. Liq. Chromatogr. 1992, 15, 2787. 

W. D. Conway, Countercurrent Chromatography Apparatus, Theory and Applications, VCH, New York, 1990. A. Foucault (ed.). Centrifugal Partition Chromatography, Marcel Dekker, Inc., New York, 1995. 

Ito, Y, Foam countercurrent chromatography New foam separation technique with flow-through coil planet centrifuge, Separ. Sci. 11 201 (1976). 

In all cases, countercurrent chromatography (CCC) utilizes a hydrodynamic behavior of two immiscible liquid phases through a tubular column space which is free of a solid support matrix. The most versatile form of CCC, called the hydrodynamic equilibrium system, applies a rotating coil in an acceleration field (either in the unit gravity or in the centrifuge force field). Two immiscible liquid phases confined in such a coil distribute themselves along the length of the coil to form various patterns of hydrodynamic equilibrium [1],... 

Y. Ito and R. L. Bowman, Countercurrent chromatography with flow-through centrifuge without rotating seals. Anal Biochem. 85 614-617 (1978). 

J. L. Sandlin and Y. Ito, Large-scale preparative countercurrent chromatography with a coil planet centrifuge,/. Liquid Chromatogr. 5(12) 2153-2171 (1985). Y. Ito and R. Bhatnagar, Improved scheme for preparative CCC with a rotating coil assembly, /. Chromatogr. 207 171-180 (1981). 

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