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A facile, preparative low-pressure chromatographic process was developed for purification of paclitaxel from crude extract of Taxus spp. The process consisted of normal-phase and a reversed-phase chromatography without utilization of any liquid-liquid partition step. The normal phase chromatography was designed lo separate paclitaxel from a majority of unwanted compounds to obtain an initial purification. Silica gel and Al2O3, were compared as packing materials for this step. The result demonstrated that basic Al2O3 was better than silica gel to give a higher throughput. A further advantage of the Al2O3 was its ability of removing l0-deacetyl-7-epipaclitaxel. a compound difficult to be separated from the paclitaxel in subsequent purification. The chromatographic fraction of A2O3 was purified by a subsequent reversed-phase column chromatography, employing a novel uniform porous microsphere, named PST, as the packing material. Combination of the two steps of column chromatography and one step of crystallization was able to purify paclitaxel, from 0.46% to more than 98% with the total recovery- of 71%. This integrated chromatographic procedure was reproducible, efficient, and simple to use. [ABSTRACT FROM AUTHOR]

A rapid, facile, and environmentally friendly process was developed for purification of huperzine A (HupA) and huperzine B (HupB) from the Chinese traditional herb Huperzia serrata . The process consisted of two steps of preparative low-pressure liquid chromatography (LPLC) on two polystyrene based resins, successively. The first step removed a large amount of impurities and captured HupA and HupB using Amberlite XAD-4 from the herbal extraction prepared by 1% aqueous H 2 SO 4 . This step was more efficient than multi-cycle liquid-liquid extraction as an initial separation step. The second step was able to separate HupA and HupB, employing a novel uniform polystyrene based porous microsphere named PST as the packing material. The PST column demonstrated a better separation and shorter run time compared with a commercial C 18 column. The mobile phases used in both LPLC's simply consisted of water and ethanol that are considered to be of low toxicity. Combination of the XAD-4 and PST chromatography and one step of crystallization enabled purification of HupA and HupB from 0.18% and 0.08% to 98.2% and 98.8%, respectively, with total recoveries of 82.8% and 84.3%. [ABSTRACT FROM AUTHOR]