Facile, general and productive syntheses of the fluorescent wye (4,9-dihydro-4,6-dimethyl-9-oxo-1H-imidazo[1,2-a]purine) in phenylalanine tRNA, its 2-substituted derivatives and 7-aza analogues
作者:Tomohisa Nagamatsu、Hiroo Yamasaki
DOI:10.1039/c39950002041
日期:——
Novel syntheses of 4,9-dihydro-4,6-dimethyl-9-oxo-1H-imidazo[1,2-a]purine (Y base skeleton), its 2-substituted derivatives and 7-aza analogues and their fluorescence characteristics in relation to their structures are described.
Synthesis of 3,9-dialkylguanines and their conversion into 3-alkylwyes, models for the fluorescent nucleosides from phenylalanine transfer ribonucleic acids
作者:Taisuke Itaya、Kazuo Ogawa
DOI:10.1016/0040-4020(82)80248-2
日期:——
e-4- carboxamides 3 followed by base-catalysed cyclisation. Cyclocondensation of 9-alkyl-3-methylguanines 5a, d, f with MeCOCH2Br gave 3-alkylwyes 6, model compounds of the most probable structure for wyosine from Torulopsis utilis tRNAPhe.
Studies towards the synthesis of the fluorescent bases of phenylalanine transfer ribonucleic acids: Synthesis of 7-methylwye isolated from extremely thermophilic archaebacteria.
Although the reactions of lithiated 7 with electrophiles gave the 2-substituted derivatives 14, 15, 17, 20, 21, and 22, lithiation of 1-benzyl-7-bromo-2-chlorowye (23) followed by treatment with Me2CHCH2CHO (13) successfully introduced a side chain at the 7-position to afford 1-benzyl-2-chloro-7-(1-hydroxy-3-methylbutyl)wye (24). Cyclization of 1-benzyl-3-methylguanine (5) with 3-bromo-2-butanone followed
A simple synthesis of 3-β-<scp>D</scp>-ribofuranosylwye and the stability of its glycosidic bond
作者:Taisuke Itaya、Tomoko Watanabe、Hiroo Matsumoto
DOI:10.1039/c39800001158
日期:——
Treatment of 5-(methylamino)-1-β-D-ribofuranosylimidazole-4-carboxamide (3) with CNBr followed by cyclization and reaction with bromoacetone gave 3-β-D-ribofuranosylwye (2) whose glycosidicbond was cleaved rapidly in acidic or alkaline solution, but was fairly stable at pH 5–8·5 at 37 °C.
The glycosidic bond of 3-β-D-ribofuranosylwye (1) has been found to undergo not only hydrogen ion catalysed cleavage but also general base catalysed or nucleophilic cleavage; steric assistance has been shown to account for its unusual susceptibility to acid.