A system for the production of [14C]taxol in vitro has been devised. The aseptic system utilized an appropriate 14C-labeled precursor, a reducing environment (dithiothreitol) and aseptically prepared pieces of the inner bark of Taxus brevifolia (Pacific yew). [14C]Phenylalanine and [14C]leucine are the best precursors, of the compounds tested, for [14C]taxol production. However, in the standard assay sodium [1-14C]acetate is used because of its relatively low price and its ability to label taxol uniformly. Chlorocholine chloride, an inhibitor of plant steroid metabolism, was an effective stimulator of [14C]taxol production, as were certain fungal elicitors. Taxol biosynthetic activity is greatest in the bark from lower portions of the main stem (trunk: 1 m from ground level).
- Pacific yew