7-substituted 7-deaza-2′-deoxyadenosines and 8-aza-7-deaza-2′-deoxyadenosines:: Fluorescence of DNA-base analogues induced by the 7-alkynyl side chain
7-substituted 7-deaza-2′-deoxyadenosines and 8-aza-7-deaza-2′-deoxyadenosines:: Fluorescence of DNA-base analogues induced by the 7-alkynyl side chain
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DOI：
10.1002/(sici)1522-2675(20000510)83:5
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发表时间：
2000-01-01
影响因子：
1.8
通讯作者：
Deimel, M
中科院分区：
文献类型：
--
作者：
Seela, F;Zulauf, M;Deimel, M
7-炔基化 7-脱氮腺嘌呤（吡咯并[2.3-d]嘧啶-4-胺）2'-脱氧核糖核苷显示出由 7-炔基 sids 链诱导的强荧光（表 3）。当化合物在 280 nm 处照射时，观察到发射大约 400 nm 的大斯托克斯位移。溶剂依赖性表明带电过渡态的形成。当三键与杂环碱基共轭时出现荧光。三键上的供电子取代基会增加荧光。少量的吸电子残基可将其还原。相比之下，7-炔基化 8-氮杂-7-脱氮腺嘌呤（吡唑并[3,4-d]嘧啶-4-胺）2'-脱氧核糖核苷的荧光相当弱（表 4）。测量量子产率和荧光衰变时间。 7-炔基化7-duaLa-'.-dc氧化腺苷和Xa的合成； aza-7-deaza-2'-脱氧腺苷以 7-deaza-2'-脱氧-7-碘腺苷 (6) 或 8-aza-7-deaza-2' 脱氧-7-碘腺苷 (22) 作为起始原料，并采用 Pd'' 催化的与相应炔烃的交叉偶联反应进行（方案 1、4 和 5）。不饱和核苷5和17的侧链催化氢化分别得到7-烷基衍生物18和19，其不显示显着的荧光（方案2）。
7-Alkynylated 7-deazaadenine (pyrrolo[2.3-d]pyrimidin-4-amine) 2'-deoxyribonucleosides show strong fluorescence which is induced by the 7-alkynyl sids chain ( Table 3). A large Stokes shift with an emission around 400 nm is observed when the compound is irradiated at 280 nm. nle solvent dependence indicates the formation of a charged transition state. The fluorescence appears when the triple bond is in conjugation with the heterocyclic base. Electron-donating substituents at the triple bond increase the fluorescence. Hliile electron-withdrawing residues reduce it. In comparison the 7-alkynylated 8-aza-7-deazaadenine (pyrazolo[3,4-d]pyrimidin-4-amine) 2'-deoxyribunucleosides are rather weakly fluorescent (Table 4). Quantum yields and fluorescence decay rimes are measured. The synthesis of the 7-alkynylated 7-duaLa-'.-dc oxyadenosines and Xa; aza-7-deaza-2'-deoxyadenosines was performed with 7-deaza-2'-deoxy-7- iodoadenosine (6) or 8-aza-7-deaza-2' deoxy-7-iodoadenosine (22) as starting materials and employing the Pd"-catalyzed cross-coupling reaction with the corresponding alkynes (Schemes,1, 4, and 5). Catalytic hydrogenation of the side chain ol. die unsaturated nucleosides 5 and 17 afforded the 7-alkyl derivatives 18 and 19. respectively, which do not show significant fluorescence (Scheme 2).