6-methylpurine and 6-methylpurine-riboside

Efficient methods for the synthesis of 6-methylpurine (3), 9-(2-deoxy-beta-D-erythro-pentofuranosyl)-6-methylpurine (8), and 6-methyl-9-beta-D-ribofuranosylpurine (5) are described. Methodology involving the (Ph3P)4Pd catalyzed cross-coupling reaction of CH3ZnBr with several different 6-chloropurine derivatives is described in high yield. This methodology now provides a facile and high-yielding synthesis of 8, which is needed in significant amounts for studies in cancer gene therapy.

Topics: Antineoplastic Agents; Bromides; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Magnetic Resonance Spectroscopy; Monosaccharides; Nucleosides; Purine Nucleosides; Purines; Zinc Compounds

We used a gene transfer-based system to generate highly toxic purine bases in tumor cells transfected with the Escherichia coli purine nucleoside phosphorylase (PNP) gene. Because these toxic purines are membrane permeant, they mediate effective killing of neighboring cells that do not express E. coli PNP ("bystander" toxicity). In mixed cultures containing increasing percentages of cells with gene expression, 100% cancer cell growth arrest and total population killing was demonstrated when as few as 1-2% of cells expressed E. coli PNP. We used E. coli PNP to test bystander killing of human melanoma cells. A 529-bp region upstream of the human tyrosinase gene start site was shown to direct melanoma-specific expression in human cell lines. When this human tyrosinase regulatory region was used to control E. coli PNP expression, profound toxicity was observed in melanoma cells after treatment with the relatively nontoxic substrate 6-methylpurine-deoxyriboside, which is converted by E. coli PNP into the highly toxic purine base 6-methylpurine. Bystander toxicity was estimated as at least 100 cells killed for each cell expressing E. coli PNP, a level substantially higher than that of other tumor sensitization genes currently being used in clinical trails. These results suggest that the high bystander activity of the system could lead to significant antimelanoma responses in vivo.

Topics: Base Sequence; Escherichia coli; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genes, Reporter; Genetic Therapy; Humans; Luciferases; Melanoma, Experimental; Molecular Sequence Data; Monophenol Monooxygenase; Prodrugs; Promoter Regions, Genetic; Purine Nucleosides; Purine-Nucleoside Phosphorylase; Purines; Tumor Cells, Cultured

6-Methylpurine, 6-methyl-9-beta-D-ribofuranosylpurine and 6-hydroxymethyl-9-beta-D-ribofuranosylpurine were isolated from mycelial cultures of Collybia maculata and their antifungal, cytotoxic and antiviral activities investigated. This is the first report on the natural occurrence of these compounds.

Topics: Adenosine Deaminase Inhibitors; Animals; Antifungal Agents; Antineoplastic Agents; Antiviral Agents; Basidiomycota; Carcinoma, Ehrlich Tumor; Cell Line; Cell Survival; DNA Replication; Fungi; Kinetics; Mice; Nucleoside Deaminases; Purine Nucleosides; Purines; Vesicular stomatitis Indiana virus; Virus Replication

Topics: Animals; Bacillus subtilis; Cells, Cultured; Fibroblasts; Mice; Mice, Inbred Strains; Mycoplasma; Pentosyltransferases; Purine Nucleosides; Purine-Nucleoside Phosphorylase; Purines