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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Pharmaceutical research 10 (1993), S. 521-524 
    ISSN: 1573-904X
    Keywords: Taxus brevifolia ; taxol ; taxane-7-xylosides ; 10-deacetylbaccatin III ; 10-deacetyltaxol ; cephalomannine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The published procedures for the isolation of taxol from the Pacific yew (Taxus brevifolia) and other species of Taxus are cumbersome, and the yields of taxol are in the range of 0.0075–0.01%. This paper describes a simple and efficient procedure for the isolation of taxol and its major natural analogues from the bark of T. brevifolia consisting of a single chromatographic column (using silica gel, Florisil, or a reverse-phase C18-silica), followed by crystallization. Isolated yields of taxol from five “pooled” bark samples (blended from many different batches by the supplier) were in the range of 0.02–0.04%, and from bark collected from a more restricted locale, yields reached 0.06%. The procedure also yielded taxol analogues, such as 10-deacetylbaccatin III (0.02–0.04%), 10-deacetyltaxol-7-xyloside (0.06-0.1%), taxol-7-xyloside (0.005–0.01%), 10-deacetyltaxol (0.01–0.02%), 10-deacetylcephalomannine-7-xyloside (0.006–0.01%), and cephalomannine (0.005–0.007%). Of these, 10-deacetyltaxol-7-xyloside is the most abundant taxane in the Pacific yew bark.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-904X
    Keywords: taxol ; 10-deacetyltaxol ; 10-deacetyltaxol-7-xyloside ; taxol-7-xyloside ; 10-deacetyltaxol-C-7-xyloside ; reverse-phase ; C-18-silica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. In view of the demonstrated antitumor activity of taxol, ready availability of the drug is important. The current isolation methods starting from the bark of Taxus brevifolia involve multiple manipulations, leading to only taxol and in a yield of 0.01%. A new process consisting of a single reverse phase column is introduced here, and the present purpose is to determine its large scale applicability. Methods. The chloroform extractable fraction of the bark of T. brevifolia is applied directly on to a C-18 bonded silica column in 25% acetonitrile/water, with elution using a step gradient: 30–50% acetonitrile/water. On standing, eight different taxanes, including taxol, crystallize out directly from different fractions. The crystals are filtered and purified further by recrystallization. Taxol and four other taxanes are purified this way. The other three require a short silica column. Taxol is freed from cephalomannine by selective ozonolysis. Results. The large scale process gave taxol (0.04%), 10-deacetylbaccatin III (0.02%), 10-deacetyl taxol-7-xyloside (0.1%), 10-deacetyl taxol-C-7-xyloside (0.04%), 10-deacetyl cephalomannine-7-xyloside (0.006%), taxol-7-xyloside (0.008%), 10-deacetyl taxol (0.008%) and cephalomannine (0.004%). Processing of the needles of T. brevifolia gave brevifoliol (0.17%), and that of the wood, 10-deacetyl taxol-C-7-xyloside (0.01%) and 10-deacetyl taxol-C. Conclusions. The reverse phase column process is simpler (one column, direct crystallization), more efficient (eight taxanes obtained simultaneously) and also gives higher yields.
    Type of Medium: Electronic Resource
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