Paclitaxel anticancer drug

Terwogt, J.M.M., Huinink, W.W.T., Schellens, J.H.M., Schot, M., et al. (2001) Phase I clinical and pharmacokinetic study of PNU166945, a novel water-soluble polymer-conjugated prodrag of paclitaxel. Anticancer Drugs 12 315-323. 

Skubitz, K. M., A phase I study of ambulatory continuous infusion paclitaxel. Anticancer Drugs, 8(9), 823, 1997. 

Triazine Paclitaxel Anticancer drug delivery system PEG chains Lim and Simanek (2008)... 

The significance of P-gp, however, in affecting absorption and bioavailability of P-gp substrate drugs can be seen in studies in knockout mice that do not have intestinal P-gp. The gene responsible for producing that protein has been knocked out of the genetic repertoire. Those animals evidenced a sixfold increase in plasma concentrations (and AUC, area under the plasma concentration-time curve) of the anticancer drug paclitaxel (Taxol) compared to the control animals [54]. Another line of evidence is the recent report... 

Anticancer drugs Paclitaxel Docetaxel Vinblastine Vincristine Tipifarnib Diflomotecan Iiinotecan Doxorubicin Daunorubicin Etoposide Tenoposide Tamoxifen (i)... 

Anticancer drugs Methotrexate Doxorubicin Daunorubicin Epirubicin Etoposide Vincristine Vinblastine Paclitaxel Iiinotecan... 

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). ... 

Most anticancer drugs damage hair follicles and produce partial or complete alopecia. Patients should be warned of this reaction, especially if paclitaxel, cyclophosphamide, doxorubicin, vincristine, methotrexate, or dactinomycin is used. Hair usually regrows normally after completion of chemotherapy. 

Paclitaxel is among the most active of all anticancer drugs, with significant efficacy against carcinomas of the breast, ovary, lung, head, and neck. It is combined with cisplatin in the therapy of ovarian and lung carcinomas and with doxorubicin in treating breast cancer. 

A brilliant example for the industrial-scale application of plant cell fermentation is the new process for the production of the anticancer drug paclitaxel developed by Bristol-Myers Squibb (see Figure 15.1). It starts with clusters of paclitaxel producing cells from the needles of the Chinese yew, T. chinensis, and was introduced in 2002. The API is isolated from the fermentation broth and is purified by chromatography and crystallization. The new process substitutes the previously used semisynthetic route. It started with lO-deacetylbaccatin(III), a compound that contains most of the structural complexity of paclitaxel and can be extracted from leaves and twigs of the European yew, T. baccata. The chemical process to convert 10-deacetylbaccatin(III) to paclitaxel is complex. It includes 11 synthetic steps and has a modest yield. 

The taxanes are a group of polycyclic diterpenes produced by various species of trees (such as yew) and are most commonly known as the potent anticancer drug paclitaxel (Taxol). The extraction process is costly. 

One of the simplest and most significant of the diterpenes is phytol, a reduced form of geranylgeraniol, which constitutes the lipophilic side-chain of the chlorophylls. Phytol also forms a part of vitamin E (tocopherols) and K molecules. Vitamin A is also a 20-carbon-containing compound, and can be regarded as a diterpene. However, vitamin A is formed from a cleavage of a tetraterpene. Among the medicinally important diterpenes, paclitaxel, isolated from Taxus brevifolia (family Taxaceae), is one of the most successful anticancer drugs of modern time. 

Another area in which natural products have had a major impact on longevity and quality of life is in the chemotherapy of cancer (see Chapter 62). In fact, most major anticancer drugs are derived from plants or microorganisms. Important examples include bleomycin, doxorubicin, daunorubicin, vincristine, vinblastine, mitomycin, streptozocin, and most recently, paclitaxel... 

Paclitaxel, camptothecin, vincristine, vinblastine, and other compounds currently under development as potential anticancer drugs (i.e., the bryostatins isolated from marine dinoflagellates) were discovered through a broad-based screening program to identify, using a whole-cell inhibition assay, natural products that are active against a battery of representative cancer cell lines. 

Because of the oil solubility of paclitaxel and the thermodynamic properties of LCM, paclitaxel is able to attach to LCM. (For the same reasons, a similar ease of incorporation into LCM has been noted for other small, low water-solubility, anticancer drugs [that are otherwise underutilized clinically and/or unpatented] which are being examined currently, such as various oxysterols [like 7 3-hydroxycholesterol] these oxysterols have been reported to inhibit tumor cell proliferation, and gliosis (cf. Section 14.2.2(i)), both in vitro and in vivo (ref. 607-611).)... 

The second chapter addresses new facets of the medicinal chemistry of the important anticancer drug Taxol (paclitaxel). Ojima and coworkers explore, in particular, the structure-activity relationship associated with the 3-phenylisoserine side chain, synthetically exploiting their P-Lactam Synthon Method . Their research has led to, among other things, a series of noteworthy second-generation taxoid anticancer agents. 

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