The efficient isolation of secondary metabolites from Chilean native fruits by counter-current chromatography

The analysis of secondary metabolites from natural products its not simple due to the high structural variety, large number of compounds and different physicochemical properties [1]. Hence, chromatography is a pre-requisite for the isolation of compounds for complete structural characterization [1]. Counter-current chromatography (CCC) was developed as an alternative to conventional methods, with the high advantage of lack of solid support [2]. The solvent system can be adjusted according to the polarity of the target compounds to favor separation based upon their partition coefficients [3]. The aim of this work is to describe the isolation and structural characterization of secondary metabolites from Chilean fruits, including Ribes and Gaultheria berries, Gevuina avellana nuts, and the arils of Prumnopitys andina.

Four anthocyanins were isolated from the Ribes species, including delphinidin and cyanidin glycosides and rutinosides. From Gaultheria species, four anthocyanins were isolated and were identified as cyanidin and delphinidin arabinosides and galactosides. In addition, the arabinoside and rhamnoside of quercetin, as well as three monotropein-derivatives were obtained. From Gevuina avellana, two dipeptides were isolated from the roasted samples. In the arils of Prumnopitys andina, the steroid 20-hydroxyecdysone was found. All the isolated compounds were obtained with high purity and were structurally characterized by extensive NMR analysis, QTOF mass spectrometry, absorbance profile and IR spectrum. CCC proved to be a valuable tool for the isolation of main secondary metabolites in complex mixtures from Chilean native fruits. The isolated compounds are being assessed for the bioactivity and health-promoting properties of native Chilean food resources.

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• References

• 1 Wolfender J-L, Marti G, Thomas A, Bertrand S. Current approaches and challenges for the metabolite profiling of complex natural extracts. J Chromatogr A 2015; 1382:: 136-164.
• 2 Berthod A, Faure K. Separations with a liquid stationary phase: countercurrent chromatography of centrifugal partition chromatography. Anal Sep Sci 2015; 1: 1177-1206.
• 3 Ito Y. Golden rules and pitfalls in selecting optimum conditions for high-speed counter-current chromatography. J Chromatogr A 2005; 1065: 145-168 .