- E-ring-modified 7-oxyiminomethyl camptothecins: Synthesis and preliminary in vitro and in vivo biological evaluation
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In contrast to five-membered E-ring analogues, 7-oxyiminomethyl derivatives of homocamptothecins showed ability to form stable ternary complexes with DNA and topoisomerase I. The 7-oxyiminomethyl derivatives of homocamptothecins were evaluated as a racemi
- Giannini, Giuseppe,Marzi, Mauro,Cabri, Walter,Marastoni, Elena,Battistuzzi, Gianfranco,Vesci, Loredana,Pisano, Claudio,Beretta, Giovanni Luca,Cesare, Michelandrea De,Zunino, Franco
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Read Online
- Electron paramagnetic resonance (EPR) study of spin-labeled camptothecin derivatives: A different look of the ternary complex
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Camptothecin (CPT) derivatives are clinically effective poisons of DNA topoisomerase I (Top1) able to form a ternary complex with the Top1-DNA complex. The aim of this investigation was to examine the dynamic aspects of the ternary complex formation by means of site-directed spin labeling electron paramagnetic resonance (SDSL-EPR). Two semisynthetic CPT derivatives bearing the paramagnetic moiety were synthesized, and their biological activity was tested. A 22-mer DNA oligonucleotide sequence with high affinity cleavage site for Top1 was also synthesized. EPR experiments were carried out on modified CPT in the presence of DNA, of Top1, or of both. In the last case, a slow motion component in the EPR signal appeared, indicating the formation of the ternary complex. Deconvolution of the EPR spectrum allowed to obtain the relative drug amounts in the complex. It was also possible to demonstrate that the residence time of CPT "trapped" in the ternary complex is longer than hundreds of microseconds.
- Ricci, Antonio,Marinello, Jessica,Bortolus, Marco,Sánchez, Albert,Grandas, Anna,Pedroso, Enrique,Pommier, Yves,Capranico, Giovanni,Maniero, Anna Lisa,Zagotto, Giuseppe
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experimental part
p. 1003 - 1009
(2011/04/25)
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- CAMPTOTHECIN DERIVATIVES
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Various 14-Nitro, 14-amino, and 14-substituted amino camptothecin derivatives are useful in the treatment of cancer and other hyperproliferative diseases. Various 14-nitro camptothecin derivatives are conveniently prepared by reacting a camptothecin deriv
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Page/Page column 68-69
(2010/12/31)
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- CRYSTALLINE FORM II OF 7-(DIMETHOXY-METHYL) CAMPTOTHECIN, ITS USE AS INTERMEDIATE AND PRODUCTS OBTAINED THEREFROM
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This invention relates to a process for preparing a crystalline form of (4S)-11-(dimethoxymethyl)-4-ethyl-4-hydroxy-1H-pyrano[3',4':6,7]indolizino[1,2-b]qui-no line-3,14(4H,12H)-dione (also named 7-(dimethoxy-methyl)camptothecin). With the provision of a particular crystallization step, in appropriate way, a new crystalline form of the above compound is obtained. The process for the preparation of the polymorph Form II comprises transforming camptothecin to the corresponding 7-(dimethoxy-methyl)-camptothecin, and crystallizing it from methanol.
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Page/Page column 8
(2009/03/07)
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- CAMPTOTHECINS WITH A MODIFIED LACTONE RING
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Compounds of formula (I) or (II) are described: where the groups are as defined in the description here below, the racemic mixtures, their individual enantiomers, their individual diastereoisomers, their mixtures, and their pharmaceutically acceptable sal
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- Chemical modification of an antitumor alkaloid camptothecin: Synthesis and antitumor activity of 7-C-substituted camptothecins
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A radical substitution reaction of 20(S)-camptothecin (1) with methanol furnished 7-hydroxymethylcamptothecin (2). Reaction of 1 with primary alcohols higher than methanol gave 7-alkylcamptothecins (4), of which alkyl groups were one carbon less than the alcohols used and also 7-hydroxyalkylcamptothecins (5). For the preparation of 7-alkylcamptothecin (4), aldehydes were used as a radical source and several alkylated derivatives were synthesized. 7-Acyloxymethyl derivatives (6), 7-carbaldehyde (7), iminomethyl derivatives (10), acid (11), esters (12) and amides (13) were synthesized starting from 2. 7-Ethyl- (4b) and 7-propylcamptothecin (4c), acyloxymethyl compounds 6a, 6c and ethyl ester (12b) exhibited higher antitumor activity than 1 against L1210 in mice.
- Sawada,Nokata,Furuta,Yokokura,Miyasaka
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p. 2574 - 2580
(2007/10/02)
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