Counter-current Chromatography Separation Research Articles

Increasing the speed of droplet counter-current chromatography separations

Un systeme de vannes permet de traiter simultanement des groupes de colonnes, ce qui limite le parcours de solvant, diminue la pression de travail, entrainant une diminution de 30% des durees de lavage et chargement des colonnes

Three highly oxygenated flavone glucuronides in leaves of Spinacia oleracea

Droplet counter-current chromatographic separation and subsequent TLC demonstrated the existence of at least 14 phenolics in the leaves of Spinacia oleracea. Three have now been isolated and identified, respectively, as the 4′-glucuronides of 5,7,4'-trihydroxy-3,6,3′-trimethoxyflavone (jaceidin), 5,3′,4′-trihydroxy-3-methoxy-6:7-methylene-dioxyflavone and 5,4′-dihydroxy-3,3′-dimethoxy-6:7-methylenedioxyflavone.

Countercurrent Chromatographic Separation of Bacteria with Known Differences in Surface Lipopolysaccharide

Abstract Countercurrent chromatography was used to separate cells of Salmonella typhimurium whose surfaces were identical except for the proportion of lipopolysaccharide molecules with long versus short chain polysaccharide chains. Large differences in partition properties resulted from slight differences in polysaccharide composition, and the results suggest that the physical state of the molecules, as well as their composition, can affect the partition of such cells.

Synergistic Use of Countercurrent Chromatography and High Performance Liquid Chromatography for the Purification of Synthetic Peptides

Abstract Examples are given demonstrating how countercurrent chromatography (CCC) and high performance liquid chromatography (HPLC) can be used together to purify synthetic peptides. In one example, CCC provided a preliminary purification of Met-Arg-Asp-Val-Val-Leu-Phe-Glu-Lys by enabling separation of ultraviolet absorbing, ninhydrin-negative material from the desired peptide. Final purification was achieved with HPLC without risk of harming the HPLC column. In a second example Tyr-Ala-Ala-Nle-Ala-Ala was completely purified by CCC with the CCC separation rapidly and conveniently monitored by HPLC. CCC appears to be a very useful technique for the peptide chemist.

Studies on the alkaloids of papaveraceous plants. XXII. Separation of the alkaloids by droplet countercurrent chromatography. 2. The quaternary bases of Corydalis pallida var. tenuis Yatabe (author's transl)

The droplet countercurrent chromatographic separation of the quaternary bases has been examined. From the quaternary base fraction of Corydalis pallida var.tenuis YATABE, palmatine chloride, dehydrocapaurine chloride, dehydrocorydalmine chloride, dehydrocapaurimine chloride, and choline chloride were isolated.

Countercurrent Chromatographic Separation of Catecholamine Metabolites from Urine

Abstract A continuous-flow method is described for achieving high-resolution separations with liquid-liquid partition without the use of an inert support. The instrument consists of a 60-m coil of Teflon tubing (0.85 mm i.d.) mounted planetarily on a centrifuge arm. The coil is filled with the stationary phase and the mobile phase is pumped through the column in a direction opposing the flow of the stationary phase imposed by centrifugal force. With ethyl acetate as the stationary phase and an aqueous solution of NaCl (5 g/100 ml) and acetic acid (10 ml/100 ml) as the mobile phase, (3-methoxy-4-hydroxyphenyl)-hydroxyacetic acid (VMA) and (3-methoxy-4-hydroxyphenyl)-acetic acid (HVA), the major products of catecholamine metabolism, elute in 2 and 7 h, respectively. With a 280 nm-monitor on the effluent, abnormal amounts of these two compounds can be detected in 1 ml of urine. The fractions containing these compounds were analyzed by both gas—liquid and thin-layer chromatographic methods. HVA is essentially completely separated from other compounds. Although VMA is found with 3-8 other unknown compounds, none interferes with any of the colorimetric assays for VMA. Several abnormal urines from patients with various types of neurosecretory tumors were examined, and a distinctive pattern of urinary excretion of these compounds was seen for each type of case.