A mass spectrometry guided elution-extrusion counter-current chromatography protocol for isolation of eighteen terpenoids from Fructus Corni and assessment of their anti-glioma activities

The utilization of counter-current chromatography (CCC) requires the assistance of the analytical instruments to measure the distribution constants (KC) values and to monitor the CCC running process. Due to the limitation of the conventional detection means, CCC is not ideal for isolating low-concentration components which are most likely to be new compounds. We introduced ion current extraction (ICE), a MS-based data post-acquiring method, to be an auxiliary tool to prominently boost CCC separation power and scope in the current work. An elution-extrusion CCC protocol was set up. For the first time, ICE was applied to process LC-MS and CCC-MS data so that extracted ion currents (EICs) of target c"onstituents were generated. In the obtained LC-EIC and CCC-EIC chromatograms obtained, the target peaks were reinforced and the chemical noise was diminished, which facilitated the KC values determination and the target compounds fractionation. Eighteen terpenoids including a new compound were isolated from Fructus Corni. Their bioactivities were tested in glioma cell U87 and LN229, which revealed remarkable inhibiting effects from triterpenoids in this plant. The proposed CCC strategy showed potential to discover, analyze, trace and fractionate chemicals, especially minor ones that are possibly novel or bioactive compounds, from a complex sample.