Synthesis and cytotoxicity of 4′-C- and 5′-C-substituted toyocamycins
摘要:
Toyocamycin and some analogues have shown potent antitumor activities; however, none of them could be used clinically primarily owing to their cytotoxicity to normal human cells. In order to overcome the weakness of these nucleoside analogues, substitution of a variety of modified sugars for the ribofuranose was explored in our laboratories with expectation that certain sugar-modified toyocamycin analogues may be selectively cytotoxic to cancer cells. In this article, we report synthesis and cytotoxicity of 4'-C- and T-C-substituted toyocamycins, which were prepared via the condensations of 4-C- and 5-C-substituted ribofuranose derivatives 11, 12, 13, 20, 21, and 26 with the silylated form of 4-amino-6-bromo-5-cyanopyrrolo[2,3-d]py (27) and subsequent debromination and debenzoylation. When compared to the parent toyocamycin, all these analogues showed much lower cytotoxicity to human prostate cancer cells (HTB-81), mouse melanoma cancer cells (B16) as well as normal human fibroblasts. Compound le showed a significant cytotoxicity to the prostate cancer cells and a moderate selectivity. The results suggested that sugar modifications, especially those that may affect phosphorylation of nucleosides, could alter cytotoxicity profile significantly. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis and cytotoxicity of 4′-C- and 5′-C-substituted toyocamycins
摘要:
Toyocamycin and some analogues have shown potent antitumor activities; however, none of them could be used clinically primarily owing to their cytotoxicity to normal human cells. In order to overcome the weakness of these nucleoside analogues, substitution of a variety of modified sugars for the ribofuranose was explored in our laboratories with expectation that certain sugar-modified toyocamycin analogues may be selectively cytotoxic to cancer cells. In this article, we report synthesis and cytotoxicity of 4'-C- and T-C-substituted toyocamycins, which were prepared via the condensations of 4-C- and 5-C-substituted ribofuranose derivatives 11, 12, 13, 20, 21, and 26 with the silylated form of 4-amino-6-bromo-5-cyanopyrrolo[2,3-d]py (27) and subsequent debromination and debenzoylation. When compared to the parent toyocamycin, all these analogues showed much lower cytotoxicity to human prostate cancer cells (HTB-81), mouse melanoma cancer cells (B16) as well as normal human fibroblasts. Compound le showed a significant cytotoxicity to the prostate cancer cells and a moderate selectivity. The results suggested that sugar modifications, especially those that may affect phosphorylation of nucleosides, could alter cytotoxicity profile significantly. (C) 2000 Elsevier Science Ltd. All rights reserved.
Compositions and methods for pyrrolo[2,3-d]pyrimidine nucleoside analogs having substituents at the C4′ and C5′ positions of the ribofuranose moiety are presented. Contemplated compositions exhibit, among other things, anti-cancer and immunomodulating effects at reduced cytotoxicity.