Taxus baccata

Ephedrine also oeeurs in the leaves of the yew tree [Taxus baccata) and in Sida rhombifolia Linn, whilst Stockman s cathine from Catha edulis Forsk has been shown by Wolfes to be d-nor- -ephedrine. Ghosh, Chopra and Dutt state that the bark of Moringa pterygosperma Gaertn. contains two alkaloids similar to ephedrine in pharmacological action. The more active of the two, moringinine, is amorphous the other is a liquid but jdelds a crystalline hydrochloride, C,H. HCl, m.p. 254-4°, + 1-8°, a picrate, m.p. 195°, and an aurichloride, m.p. 170-8°. [Pg.635]

Taxine, C3,HgiOioN, is contained in the leaves, shoots and fruits of the yew (Taxus baccata), from which it was first isolated by Lucas. It was investigated by Marm, Hilger and Brande, Amato and Capparelli, Thorpe and Stubbs, Winterstein et al., Kondo et al., Takahashi and Gulland et al. ... [Pg.769]

Taxus baccata 656 Taxus brevifolia 655 Tebbe reagent 703 telomerization 354 ff. a-terpineol 5 tertiary radicals 409, 413 tether, disposable 664 tetrahedrane 12... [Pg.797]

Anticancer drugs originally extracted from the cortex of Taxus brevifolia or Taxus baccata. They block cell division by inhibiting tubulin depolymerization. Two... [Pg.1195]

Starting from needles of Taxus baccata (1 g 10-deacetyl baccatin III obtained from 1000 g dried needles). [Pg.157]

For example, an alumina layer with a nonaqueons mobile phase was optimized for the separation of the taxoid fraction from ballast snbstances [5]. Figure 11.3 shows the densitogram obtained for Taxus baccata cmde extract chromatographed on the alnmina layer developed with nonaqueous elnents. The nse of ethyl acetate and dichloromethane enables elntion of nonpolar fractions (chlorophylls and waxes) and purification of the starting zone (Figure 11.3a). In this system, all taxoids are strongly retained on the alumina layer. The use of a more polar mobile phase... [Pg.256]

Taxoids Taxus baccata SiOj B - CHCI3 - MejCO - MeOH UV 254 Optimization of 4 C/)... [Pg.263]

FIGURE 11.21 Densitograms of PLC of Taxus baccata fraction from preparative column (silica/aqueous methanol) containing unknown taxoid (Tax 1) introduced to the layer with a set of capillaries with simultaneous evaporation of solvent from the starting band. System silica/CH2Cl2 + DX + Me2CO + MeOH (84 10 5 1). Plates double developed (a) 0.3 ml of fraction introduced (b) 0.5 ml of fraction introduced (c) 1 ml of fraction introduced to the layer. [Pg.283]

A fine example of such a semi-synthesis is the preparation of the anti-cancer drug paclitaxel (Taxol ), a relatively scarce compound from Taxus brevifolia. Here, the natural and better accessible 10-deacetylbaccatin III, isolated from the leaves of Taxus baccata, provides the complicated ring system of paclitaxel, including all substituents with the right stereostructure (Scheme 5.1). In just four reaction steps [5] paclitaxel is obtained from 10-deacetylbaccatin III. [Pg.102]

Environmental groups objected to this practice, and many demonstrations were staged. A solution was eventually found when the needles of the European yew tree Taxus baccata) provided a source for the paclitaxel precursor without destroying the bark. [Pg.58]

Paclitaxel was introduced by Bristol-Myers Squibb in 1993. Today, paclitaxel or a precursor can be obtained from cell cultures of Taxus media formed by hybridizing Taxus baccata and Taxus cuspidate. [Pg.58]

Early production of 1 kg of paditaxel required extraction from about 13,000kg of the Pacific yew tree bark. This process was refined, and pacli-taxel is now produced by a semisynthetic route. The starting material, 10-deacetyl baccatin 111 (10-DAB), is obtained from the needles of Taxus baccata (European yew) or T. wallichiana (Himalayan yew). The yield is around 1000 kg of needles to produce 1kg of 10-DAB. [Pg.337]

Evergreens are the classic choice for clipped hedges, giving a solid backdrop of color and structure year-round. Yew (Taxus baccata) and boxwood (Buxus) make traditional hedges with a smooth finish boxwood is ideal for low hedges as it grows more slowly than yew. [Pg.142]

As will be mentioned further in this chapter, the discovery of the anticancer drug, paclitaxel (21), was soon followed by sourcing issues due to the low yield of this compound in the source plant, Taxus brevifolia Nutt. This led to the semisynthesis of paclitaxel (21), from a precursor molecule, 10-deacetylbaccatin III, readily available from the leaves of Taxus baccata L., a renewable source with high yields of this compound.Docetaxel (37) is a second taxane class anticancer drug and is a semisynthetic derivative of paclitaxel (21). ... [Pg.27]

Taxol was the most triumphant new anticancer drug developed in the last few decades. It resulted from a drive to screen thousands of synthesized compounds and plant extracts, financed by the National Cancer Institute (Georg et al. 1994, Suffness 1995, Goodman and Walsh 2001). Taxol is extracted from the bark of the Pacific yew tree, or Taxus brevifoli, found in the Pacific Northwest, and has been proven effective against intractable breast and ovarian cancers. It is now produced by semi-synthetic methods from the needles of the common ornamental tree English Yew, or Taxus baccata. We will discuss taxol in greater detail in Chapter 2. [Pg.21]

Reddy, B.P. and Krupadanam, G.L.D., Chemical constituents of the leaves of Himalayan Taxus baccata use of DQF-COSY in the structure elucidation of biflavones, Indian J. Chem., 35B, 283, 1996. [Pg.1125]

The alkaloid ester paclitaxel (7.93) is a natural product derived from the western yew (Taxus brevifolia) and European yew (Taxus baccata). This agent functions as a mitotic spindle by causing excessive tubulin polymerization. Paclitaxel has demonstrated considerable clinical utility in ovarian and breast cancer. [Pg.455]

Paclitaxel is an alkaloid ester derived from the Pacific yew (Taxus brevifolia) and the European yew (Taxus baccata). The drug functions as a mitotic spindle poison through high-affinity binding to microtubules with enhancement of tubulin polymerization. This promotion of microtubule assembly by paclitaxel occurs in the absence of microtubule-associated proteins and guanosine triphosphate and results in inhibition of mitosis and cell division. [Pg.1177]

Figure 7.4 European yew tree Taxus baccata) close-up of leaves.

Large plantations of Taxus baccata had to be established to grow the bushes from which leaves and twigs were harvested on an annual basis. This process utilizes significant amounts of land and essentially comprises a monocrop. Furthermore, the harvesting process consumes energy and produces emissions. [Pg.154]

In the study reported here, Taxus baccata, T. canadensis (2/2), Taxus sp., and T. speciosa, all previously recorded as giving positive alkaloid tests, were positive. Phyllocladus alpinus (now assigned to a unigcneric family, Phyllocladaceae) and Torreya nucifera were also positive. [Pg.208]

Cyclization reactions of GGPP mediated by car-bocation formation, plus the potential for Wagner -Meerwein rearrangements, will allow many structural variants of diterpenoids to be produced. The toxic principle taxine from common yew (Taxus baccata Taxaceae) has been shown to be a mixture of at least eleven compounds based on the taxadiene skeleton which can be readily rationalized as in Figure 5.43, employing the same mechanistic principles as seen with mono- and sesqui-terpenes. [Pg.205]

Then the (2S,4S,5R)-2,4-diphenyl-3-(4-nitrobenzenesulfonamido)-5-carboxy-1,3-oxazolidine react with the 7-SDMS Baccatin III, that is 7-(3-methylbut-2-yl)dimethylsilyl baccatin III (Baccatin III 7,ll-methano-lH-cyclodeca(3,4) benz(l,2-b)oxet-5-one,6,12b-bis(acetyloxy)-12(benzoyloxy)-l,2a,3,4,4a,6, 9,10,ll,12,12a,12b-dodecahydro-4,9,ll-trihydroxy-4a,8,13,13-tetramethyl-, (2aR,4S,4aS,6R,9S,llS,12S,12aR,12bS), isolated from Taxus baccata). [Pg.2603]

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