- Radiosynthesis of carbon-11-labeled camptothecin derivatives as potential positron emission tomography tracers for imaging of topoisomerase I in cancers
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Four carbon-11-labeled camptothecin derivatives, 9-[11C]methoxy- 20(S)-camptothecin ([11C]5), 10-[11C]methoxy-20(S)- camptothecin ([11C]7), 9-nitro-10-[11C]methoxy-20(S)- camptothecin ([11C]9), and 9-[([11C]trimethylamino)methyl] -10-hydroxy-20(S)-camptothecin ([11C]11), have been synthesized as potential positron emission tomography tracers for imaging of topoisomerase I in cancers.
- Gao, Mingzhang,Miller, Kathy D.,Sledge, George W.,Zheng, Qi-Huang
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p. 3865 - 3869
(2007/10/03)
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- Water soluble C-ring analogues of 20(S)-camptothecin
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Novel water soluble C-ring analogs of 20(S)-camptothecin having the formula 1. STR1 The compounds of the formula 1 are prepared from the compounds of the formula 12 having C-20(S) chiral carbon. The compounds of the formula 1 possess potent anti-cancer and anti-viral properties.
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- Synthesis and antitumor activity of 20(S)-camptothecin derivatives: A-ring modified and 7,10-disubstituted camptothecins
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20(S)-Camptothecin derivatives having nitro, amino, chloro, bromo, hydroxyl and methoxyl groups in the A-ring were synthesized. B-Ring hydrogenated camptothecin (2a) was converted into 10-hydroxycamptothecin (6e) by treatment with lead tetraacetate in trifluoroacetic acid. 10-Substituted derivatives (6) were obtained by a photoreaction of N-oxides (9). The cytotoxicity of the A-ring modified camptothecins was evaluated against KB cells in vitro and leukemia L1210 in mice. 7-Ethyl-10-hydroxycamptothecin (6i) was identified as a potential derivative for further modification.
- Sawada,Matsuoka,Nokata,Nagata,Furuta,Yokokura,Miyasaka
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p. 3183 - 3188
(2007/10/02)
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- Camptothecin derivatives and process for preparing same
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New Camptothecin derivatives possessing high anti-tumor activity with slight toxicity, represented by the general formula: STR1 wherein R1 is a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group or an acyloxy group, R2 for a hydrogen atom, an alkyl group, an aralkyl group, a hydroxymethyl group, a carboxymethyl group or an acyloxymethyl group, and R3 is the grouping --XR' (where R' is a hydrogen atom, an alkyl group or an acyl group and X is an oxygen atom or a sulfur atom), a nitro group, an amino group, an alkylamino group, an acylamino group or a halogen atom, with the proviso that when both of R1 and R2 are hydrogen atoms, R3 should not be a hydroxyl group, methoxy group or acetoxy group. These new camptothecin derivatives are prepared by treating a 5-R1 -7-R2 -camptothecin derivative with a peroxidant and then reacting the resultant 5-R1 -7-R2 -camptothecin-1-oxide with an active hydrogen compound under irradiation of UV-rays or by catalytically hydrogenating the ring B of camptothecin in a solvent, treating the resultant tetrahydro product with an acylating agent, introducing a nitro group into the 10-position of the acylated product by the reaction with nitric acid, splitting off the acyl group in the 10-nitro product by hydrolysis and treating the hydrolyzed tetrahydro product with an oxidizing agent for dehydrogenation, and if desired, reducing the nitro group in the resulting product to an amino group and modifying the amino group by N-alkylation, N-acylation or by diazotization followed by hydrolysis or the Sandmeyer reaction, before or after the oxidation of the 10-nitro-tetrahydro product.
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