Countercurrent chromatography, based on liquid-liquid partitioning, has many technological variants. One of them is centrifugal partition chromatography, introduced by Wataru Murayama and Kanichi Nunogaki in 1982. This technique, like other countercurrent chromatography techniques, is based on the phenomenon of liquid-liquid partitioning between two immiscible liquid phases that stay at equilibrium. But the significant difference between this technique and others is the retention mechanism of stationary phase. In the case of centrifugal partition chromatography, this mechanism is based on hydrostatic force, formed by the centrifugal field in the rotor in one-axis centrifuge. Sometimes that allows more control of stationary phase, for example, when aqueous two-phase and other difficult solvent systems are used. However, the efficiency of the separation in centrifugal partition chromatography is also affected by a variety of parameters dependent on the sample properties in the solvent system, physical properties of the solvent system, parameters of the instrument, and the method. This article includes also recent ideas for improvements to the technique and broadening its application (e.g., (multiple) dual-mode or elution-extrusion procedure, pH-zone-refining centrifugal partition chromatography, ion-exchange centrifugal partition chromatography, online and offline coupling of centrifugal partition chromatography).
Epidemiological data demonstrate an inverse relationship between consumption of coffee as well as other beverages containing methylxanthines and liver fibrosis. The mechanism may include the action of not only methylxanthines but also phenolic compounds. Regarding coffee and cocoa, the levels of phenolic compounds strongly depend on the form of beans, i.e., raw (green) vs. roasted. The aim of this study was to evaluate the antifibrotic effects of coffee and cocoa extracts (both from green and roasted beans) on liver fibrosis progression in thioacetamide (TAA)-treated rats. Among the investigated extracts, only green coffee extract developed a more pronounced antifibrotic effect, partially preventing TAA-induced liver fibrosis, confirmed by the significant decrease of both total and relative hydroxyproline contents in the liver.
Cocoa bean is a rich source of polyphenols, mainly flavonoids which have a wide range of biological properties. The aim of the study was to determine the physiological indices of laboratory rats as a response to diets containing water extracts of raw or roasted cocoa beans of Forastero variety, as well as purified monomeric flavan-3-ols fraction isolated from them. The influence of these extracts on selected parameters was studied during 4 weeks feeding. The samples of rats feces were collected throughout the experiment and after its completion, biological samples (intestines content, blood, and organs) were retrieved individually from each rat and subjected to analyses. The observed changes in the gastrointestinal tract functioning indices and metabolism indicators, determined throughout the study and after its completion, confirm to some extent the biological activity of polyphenol extracts of cocoa beans. The differences in the results obtained for the analyzed parameters of the gastrointestinal tract revealed that the cocoa bean extracts differently affected the physicochemical properties of rats’ intestines. The results indicate the beneficial effects of the applied nutrition treatment on the activity of cecal enzymes and the content of volatile fatty acids in the gut.
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