Department of Analytical Chemistry, Institute C-1, Faculty of Chemical Engineering and Technology, Cracow University of Technology, Cracow, Poland.
Department of Chemistry, Jagiellonian University, Cracow, Poland.
J Sep Sci. 2019 May;42(9):1676-1685. doi: 10.1002/jssc.201801172. Epub 2019 Mar 14.
Betacyanin extract of Amaranthus cruentus L. flowers was fractionated by semi-preparative high-speed counter-current chromatography in a highly polar solvent system: propan-1-ol/acetonitrile/(NH ) SO /H O (1.0:0.5:1.2:1.0, v/v/v/v) in tail-to-head mode with 76% retention of the stationary phase. The crude extract as well as the fractions containing betacyanins were analyzed by liquid chromatography with tandem mass spectrometry as well as by high-resolution ion-trap time-of-flight mass spectrometry detection technique for the molecular formulae and multi-step fragmentation pattern elucidation. Four betacyanins; namely, amaranthin, betanin, 6'-O-formyl-amaranthin, and 6'-O-malonyl-amaranthin as well as their diastereomeric forms differing in the configuration of the C-15 carbon atom were identified in the fractions. Amaranthin was the dominant pigment in the extract and was additionally analyzed by nuclear magnetic resonance correlation techniques after the counter-current chromatographic and high-performance liquid chromatographic isolation. Betacyanins were highly enriched during a single high-speed counter-current chromatographic step; therefore, the tentative identification of new compounds for the whole Amaranthaceae family, 6'-O-formyl-amaranthin and 6'-O-malonyl-amaranthin was possible. Different elution profiles of the pigments observed in the counter-current chromatographic system in comparison to high-performance liquid chromatography system confirm a complementarity of both the techniques especially in the separation of diastereomeric pairs of betacyanins.
苋菜花甜菜红素提取物采用正相高速逆流色谱法，在高极性溶剂系统中进行分离：正丙醇/乙腈/（NH ） SO /H O（1.0:0.5:1.2:1.0，v/v/v/v），采用首尾相连模式，固定相保留率为 76%。粗提物以及含有甜菜红素的馏分均采用液相色谱-串联质谱以及高分辨离子阱飞行时间质谱检测技术进行分析，以确定分子式和多步碎裂模式。在馏分中鉴定出四种甜菜红素，即苋菜红、甜菜碱、6'-O-甲酰基苋菜红和 6'-O-丙二酰基苋菜红，以及它们在 C-15 碳原子构型上不同的非对映异构体。苋菜红是提取物中的主要色素，在逆流色谱和高效液相色谱分离后，通过核磁共振相关技术进行了进一步分析。甜菜红素在单次高速逆流色谱步骤中得到了高度富集，因此有可能对整个苋科植物家族进行新化合物的初步鉴定，即 6'-O-甲酰基苋菜红和 6'-O-丙二酰基苋菜红。与高效液相色谱系统相比，在逆流色谱系统中观察到的色素洗脱曲线不同，证实了这两种技术的互补性，特别是在甜菜红素非对映异构体对的分离方面。
