A novel C,D-spirodioxene taxoid (6) was prepared from paclitaxel (1a), with the key steps including an unexpected Pd-mediated ring cyclization. The anti-tubulin activity of 6 was decreased relative to that of 1a and a previously reported C,D-spirolactone taxane (5). These observations could be rationalized on the basis of molecular modeling results. To the best of our knowledge, this is the fir...

The synthesis of a novel D-ring modified docetaxel analogue, in which the oxetane ring is replaced with a γ-lactone, was achieved from 10-deacetylbaccatin III. The key steps of the synthesis include the direct acetylation of the secondary hydroxyl group at C-5 and D-ring opening and intramolecular aldol reaction to form the γ-lactone. In MTT assays, this analogue proved to have equipotent cytot...

The systematic investigation on the roots of Taxus wallichiana has resulted in the isolation of nine taxoids-taxol 1 baccatin III 2, baccatin IV 3, taxusin 4, a C-14 oxygenated taxoid 5, I~-hydroxybaccatin 16, pentaacetoxy taxadiene 7, a dibenzoylated rearranged taxoid 8, 7-xylosyl-1 O-deacetyl-taxol C 9 and three phenolic compounds (-) seco-isolariciresinol 11, taxiresinol 12 and isotaxiresino...

This article reviews our contribution in the ®eld of the cobalt(I)-mediated cyclizations. The use of new unsaturated partners such as allenes extend the scope and the utility of the previously developed intramolecular [2‡2‡2] cyclotrimerization. The presence of chiral auxiliaries induced high level of diastereoselectivity in the enediynes cyclization. The discovery of cobalt(I) catalyzed ene-ty...

Docetaxel is a new taxoid antineoplastic agent with clinical efficacy especially in breast cancer. One of the most distressing side-effects induced by docetaxel is alopecia. We studied the prevention of alopecia by using a cold cap in 98 patients receiving 100 mg/m2 docetaxel by 1 h i.v. infusion every 3 weeks. One patient was lost to follow-up. 83 patients (86%) were evaluated as a success to ...

Altered gamma-ray response by brief (1 h), concomitant exposure to paclitaxel (Taxol) or docetaxel (Taxotere) was investigated in growing HeLa and SQ20B human tumor cells in vitro. For both cell lines, both taxoids were able to reduce or enhance radiation cell killing, depending on the drug concentration. Large reduction of radiosensitivity (up to 3.3-fold reduction relative to radiation alone)...