HPLC-electrospray ionization-MS-MS analysis of Cephalotaxus harringtonia leaves and enhancement of the extraction efficiency of alkaloids therein by SFE.

A high-performance liquid chromatographic method is developed for use in the electrospray mass spectrometric (MS)-MS analysis of alkaloids contained in Cephalotaxus harringtonia leaves. Nine alkaloids having ester groups can be separated and detected with good sensitivity. The MS and MS-MS spectra obtained provides information on their chemical structures. Supercritical fluid extraction is also applied in order to improve the extraction efficiency of Cephalotaxus alkaloids such as cephalotaxine, harringtonine, homoharringtonine, and isoharringtonine. When carbon dioxide-methanol-water (80:18:2, v/v) is used the extraction yield is found to be higher than that using the other supercritical solvents evaluated and conventional organic solvent extraction.