Related Taxanes Research Articles

Initiation and growth of cell lines of Taxus brevifolia (Pacific yew)

Conditions have been established for the induction and maintenance of callus cultures of Taxus brevifolia (Pacific yew) from bark, stem, and needle tissues. Cultures were established on a modified Gamborg's B5 medium, 1% sucrose, 0.2% casamino acids and 1 mg/L 2,4-D. There was no apparent inhibition of callus induction as a result of taxol concentration in the explant material. Cell lines derived from explants of individual trees were used to investigate growth characteristics. Although none of the cell lines contained taxol, some contained low levels of related taxanes. Variability was observed with each cell line in response to light, and auxin type and concentration. Growth index was most affected by cell line, followed by auxin type and concentration. These culturing methods may be useful for the goal of developing a highproducing cell line applicable for large-scale taxol production.

Taxanes from Taxus baccata

A winter collection of yew needles gave two pairs of taxicin-I and taxicin-II diesters, the structures of which were established by spectral data and chemical reactions. The mixture of these diesters might correspond to the so-called ‘desdimethylaminotaxine’ of the old literature on yew. A detailed NMR analysis of the diesters allowed an unambiguous assignment of all 1H and 13C NMR resonances of these and related taxane derivatives.

High-performance liquid chromatographic assay of taxol

A reversed-phase high-performance liquid chromatographic (HPLC) method for assaying taxol bulk drug or process samples is described. The method utilizes a commercially available pentafluorophenyl (PFP) packing material that has greater selectivity for taxol and related taxanes than other reversed-phase media tested. The method has been shown to be accurate, linear, precise, specific, and rugges, and can be used to assay the bulk drug and determine its chromatographic purity as well as to assay taxol in process and biomass samples

High-Speed Countercurrent Chromatography Separation of Taxol and Related Diterpenoids fromTaxus Baccata

Abstract Taxol and related taxane diterpenoids were isolated from pre-purified extracts of stem-barks of Taxus bacccata by HSCCC. The described method allowed to obtain a mixture of taxol and cephalomannine without any other interfering constituent and furthermore a partial separation of taxol (40 % of the total recovery) from cephalomannine. In addition, the HPLC and TLC separation conditions of these compounds for the semi-preparative and analytical purposes were improved. The proposed HSCCC method could be adapted to the scaling-up separation of taxol from vew material.

Separation of taxol from related taxanes in Taxus brevifolia extracts by isocratic elution reversed-phase microcolumn high-performance liquid chromatography

Previous attempts to resolve the closely related taxanes cephalomannine and taxol by reversed-phase high-performance liquid chromatography (HPLC) on octadecyl silica columns have not been successful. In the present study, high-resolution HPLC on microcolumns packed with octadecyl silica was evaluated for the separation of the aforementioned taxanes. Due to the enhanced separation efficiency of this technique, baseline resolution between cephalomannine and taxol was readily achieved under isocratic elution conditions. Chromatographic profiles of Taxus brevifolia twig and needle foliage extracts are presented that illustrate this separation.

Structure-activity study of cytotoxicity and microtubule assembly [formula omitted] by taxol and related taxanes

Structure-activity relationships of natural and semisynthetic taxanes are reported. Activity is measured in vivo by cytotoxicity toward the macrophage-like cell line J774.2, and in vitro by promotion of microtubule assembly in the absence of exogenous GTP and by inhibition of [ 3H]taxol binding to microtubule protein. Cytotoxicity and in vitro activity require both an intact taxane ring and ester side chain at position C-13. Addition of acetyl moieties at positions 2′ and 7 results in loss of in vitro activity but not cytotoxicity.