220167-86-2Relevant academic research and scientific papers
Antitumor agents 216. Synthesis and evaluation of paclitaxel-camptothecin conjugates as novel cytotoxic agents
Ohtsu, Hironori,Nakanishi, Yuka,Bastow, Kenneth F.,Lee, Fang-Yu,Lee, Kuo-Hsiung
, p. 1851 - 1857 (2007/10/03)
Five conjugates (16-20) composed of a paclitaxel and a camptothecin derivative joined by an imine linkage were synthesized and evaluated as cytotoxic agents and as inhibitors of DNA topoisomerase I. All of the conjugates were potent inhibitors of tumor cell replication with improved activity relative to camptothecin. Significantly, compounds 16-18 were more active than paclitaxel and camptothecin against HCT-8 (colon adenocarcinoma) cell replication, and the spectrum of activity was different from a simple mixture of paclitaxel and camptothecin. All of the conjugates were significantly less potent than camptothecin as inhibitors of human topoisomerase I in vitro with 16, 18, and 19 showing only marginal activity at 50 μM. Based on activity against drug-resistant cell line replication, one could conclude that the conjugates are simply acting as 'weak taxanes', but the spectrum of activity, particularly against MCF-7 and HCT-8, strongly suggests that a novel mechanism of action has been achieved through conjugation.
Synthesis and evaluation of [14C]-labelled and fluorescent-tagged paclitaxel derivatives as new biological probes
Rao, Ch. Srinivasa,Chu, Jao-Jia,Liu, Rai-Shung,Lai, Yiu-Kay
, p. 2193 - 2204 (2007/10/03)
Our present report deals with the preparation of hitherto unreported 7-([carbonyl-14C]-acetyl)paclitaxel 4 and two new bioactive 7-substituted fluorescent taxoids (FITC 9 and rhodamine 11), as well as evaluation towards their applications as biological probes. The results in this report demonstrate that (a) the new paclitaxel derivatives 4, 9, 11 could be prepared with good yields starting from paclitaxel; (b) the [14C]acetylation step was found to be better by using [14C]acetic anhydride rather than [14C]sodium acetate; (c) the radiochemical purity of 4 was 96% and its specific activity was 48mCi/mmol; (d) the cytotoxicity of 4 was close to that of paclitaxel whereas 9, 11 were far less active than paclitaxel, but these cytotoxic levels were good enough for their biological applications; (e) the drug-quantitation by flow cytometric analysis using 9 and 11 was proved to be equally efficient with respect to the radioactivity-based determination employing 4; (f) the intracellular fluorescence mapping by 9 and 11 was found to be effective and the microtubule network pattern was visible in both the cases; (g) the overall fluorescence imaging efficiency was better with 11 while the intensity of fluorescence was higher with 9; (h) staining of nucleolus was observed in fluorescence studies of both 9 and 11. Based on these results, the newly prepared paclitaxel derivatives can be considered as efficient biological probes and should find further use in relevant applications. Copyright (C) 1998 Elsevier Science Ltd.
