Isolation and purification of four bioactive constituents from Alpinia officinarum Hance utilizing high-speed counter-current chromatography

Galangal, the rhizome of Alpinia officinarum Hance (Chinese pinyin name: Gao-liang-jiang), is one of the most popular Chinese herbs that has extensive pharmacological effects. In this study, a high-speed counter-current chromatography (HSCCC) method has been used for the first time to separate key bioactive chemical constituents from galangal. Four compounds including 5 R-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-heptanone, kaempferol-4"²-methylether, galangin, and 7-(4-hydroxy-3-methoxyphenyl)-1- phenyl-4E-en-3-heptanone were obtained from the chloroform extract of galangal using HSCCC. Their structures were identified by ESI-MS, 1H NMR, and 13C NMR. The study showed the value of orthogonal selectivity in liquid-liquid chromatography with references to an example of superior resolution in preparative HSCCC as compared to analytical HPLC, where it baseline-resolved two components that co-eluted with analytical reverse phase HPLC assay. The study also showed examples of the considerable resolution choices offered by different biphasic solvent systems.