FREE TAXANES AND THE RELEASE OF BOUND COMPOUNDS HAVING TAXANE ANTIBODY REACTIVITY BY XYLANASE IN FEMALE, HAPLOID-DERIVED CELL-SUSPENSION CULTURES OF TAXUS-BREVIFOLIA

Haploid cells derived from the female gametophyte of Taxus brevifolia produce multinucleate egglike cells that have grown as cell suspension s over a 5-yr period. Two new media are formulated, one without nitrat es, to select for haploid cell lines and to enhance free taxane produc tion when cell lines are artificially aged by withholding subculture. The cell suspensions produce bound taxanes that are detectable with an ti-taxane monoclonal antibodies on cell surfaces and on particles rele ased into the culture medium. Recovery and detection of bound taxanes are based on a competitive inhibition enzyme immunoassay (CIEIA). Tiss ues extracted exhaustively with methanol then treated with xylanase re lease CIEIA-detectable taxanes. Approximately 300% more taxanes were d etected in the xylanase-treated tissue culture material versus the con trol. Wood (winter bark) taken from T. brevifolia and treated in the s ame way with xylanase released 20% more taxanes than could be detected in the control.