title: Synthesis and cytotoxicity of 4-amino-5-oxopyrido[2,3-d]pyrimidine nucleosides.
abstract: A number of nucleoside analogues have been either used clinically as anticancer drugs or evaluated in clinical studies, while new nucleoside analogues continue to show promise. In this article, we report synthesis and cytotoxicity of a series of new pyrido[2, 3-d]pyrimidine nucleosides. 2-Amino-3-cyano-4-methoxypyridine was converted, in two steps, to 4-amino-5-oxopyrido[2,3-d]pyrimidine. A variety of 1-O-acetylated pentose sugar derivatives were condensed with silylated 4-amino-5-oxopyrido[2,3-d]pyrimidine, followed by protection, to afford a series of 4-amino-5-oxopyrido[2, 3-d]pyrimidine nucleosides. Further derivatizations provided an additional group of pyrido[2,3-d]pyrimidine nucleosides. These nucleosides were evaluated for in vitro cytotoxicity to human prostate cancer (HTB-81) and mouse melanoma (B16) cells as well as normal human fibroblasts (NHF). A number of compounds (1a,b, 2a-c,f, 3f+4d) showed significant cytotoxicity to cancer cells, with 4-amino-5-oxo-8-(beta-D-ribofuranosyl)pyrido[2,3-d]pyrimidine (1b) being the most potent proliferation inhibitor (EC(50): 0.06-0.08 microM) to all types of cells tested. However, a selective inhibition to the cancer cells was observed for 4-amino-5-oxo-8-(beta-D-xylofuranosyl)pyrido[2,3-d]pyrimidine (2b), which is a potent inhibitor of HTB-81 (EC(50): 0.73 microM) and has a favorable in vitro selectivity index (28).
authors.affiliation: Chemistry and Cancer Biology Laboratories, ICN Pharmaceuticals, Inc., 3300 Hyland Avenue, Costa Mesa, California 92626, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Girardet
authors.forename: E
authors.initials: E
authors.lastname: Gunic
authors.forename: C
authors.initials: C
authors.lastname: Esler
authors.forename: D
authors.initials: D
authors.lastname: Cieslak
authors.forename: Z
authors.initials: Z
authors.lastname: Pietrzkowski
authors.forename: G
authors.initials: G
authors.lastname: Wang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D006801:Humans; D051379:Mice; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011741:Pyrimidine Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: C415159:4-amino-5-oxo-8-xylofuranosylpyrido(2,3-d)pyrimidine; D000970:Antineoplastic Agents; D009705:Nucleosides; D011741:Pyrimidine Nucleosides; D011743:Pyrimidines