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• 19316-88-2 2-amino-1-(2-deoxy-β-D-erythro-pentofuranosyl)-5-methylpyridin-4(1H)-one 

Relevant academic research and scientific papers

Parallel-stranded oligonucleotide duplexes containing 5- methylisocytosine-guanine and isoguanine-cytosine base pairs

Parallel-stranded oligonucleotides containing 5-methylisocytosine- guanine and/or isoguanine-cytosine base pairs were prepared. The coupling efficiency was higher than 99% when the phosphoramidites of 2'-deoxy-5- methylisocytidine (2a) and of 2'-deoxyisoguanosine (3) were employed in solid-phase synthesis. The glycosylic bond of 2'-deoxy-5-methylisocytidine (1a) is stabilized against acid in the case of the amidine derivatives 4a, b. Depyrimidination occurs upon extended exposure to ammonia. The orientation of the parallel-stranded (ps) duplexes was unambiguously determined using the pyrene excimer fluorescence. The antiparallel (aps) duplex d(A12)·d(T12) (25.26) turned into the parallel orientation when two central adenine- thymine base pairs were replaced by isoguanine-cytosine pairs. The thermal stability of ps-duplexes containing 5-methylisocytosine-guanine base pairs was found to be significantly lower than that of duplexes with isoguanine, cytosine pairs. According to the CD spectra, ps-DNA-DNA or DNA-RNA hybrids show differences in their secondary structures compared to their aps counterparts.

Parallel-stranded DNA formed by new base pairs related to the isoguanine-cytosine or isocytosine-guanine motifs

Parallel-stranded (ps) oligonucleotide duplexes containing several new base pairs formed between 7-deazaisoguanine and cytosine, 8-aza-7-deaza- isoguanine and cytosine, and 5-aza-7-deaza guanine and guanine are described. The stability of the ps-hybrids increased if the duplex contains 8-aza-7- deazaisoguanine instead of isoguanine and is decreased by 7-deazaisoguanine incorporation. The purine-purine base pair between 5-aza-7-deazaguanine and guanine was found to be more stable than that of 5-methylisocytosine with guanine.