Billich A, Stockhove U, Witzel H
Nucleic Acids Res. 1983 Nov 11;11(21):7611-24. doi: 10.1093/nar/11.21.7611.
A new route for the synthesis of 1-(beta-D-allofuranosyl)uracil ("allo-uridine") and the corresponding 6'-deoxy-derivative ("6'-deoxy-allo-uridine") as well as for 1-(beta-D-altrofuranosyl) uracil ("altro-uridine") is described. NMR studies of allo-uridine revealed a preferred conformation with the base in anti-position, C-2'-endo-pucker of the sugar moiety, the 5'-OH-group above the furanose ring and the 5'-CH2OH-group in a gt position with the OH-group in the plane of the furanose ring. The same conformation is found for the 5'- and 6'-phosphate, indicated by the influence of the phosphate group on the H-6 signal. Allo-uridine is phosphorylated by the phosphotransferases from carrot and from malt sprouts only in the 6'-position. The phosphate ester is hydrolysed by unspecific phosphatases but not by 5'-nucleotidase. A (3' leads to 6')-dinucleoside phosphate is formed by pancreatic ribonuclease with 2',3'-cyclic cytidylic acid and allo-uridine. It is split by nuclease S1, but not by snake-venom phosphodiesterase. It has no primer activity for polynucleotide phosphorylase. All-uridine 6'-diphosphate could not be prepared enzymatically by nucleotide kinase or by chemical methods, where 5',6'-cyclic phosphates are formed, which are hydrolysed exclusively to 6'-monophosphates.
本文描述了一种合成1-(β-D-阿洛呋喃糖基)尿嘧啶（“阿洛尿苷”）及其相应的6'-脱氧衍生物（“6'-脱氧阿洛尿苷”）以及1-(β-D-阿卓呋喃糖基)尿嘧啶（“阿卓尿苷”）的新途径。对阿洛尿苷的核磁共振研究表明，其碱基处于反式位置、糖部分为C-2'-内型构象、5'-OH基团位于呋喃糖环上方且5'-CH2OH基团相对于呋喃糖环平面中的OH基团处于gt位置时为优选构象。5'-和6'-磷酸酯也具有相同构象，这由磷酸基团对H-6信号的影响表明。阿洛尿苷仅在6'-位被来自胡萝卜和麦芽芽的磷酸转移酶磷酸化。磷酸酯可被非特异性磷酸酶水解，但不能被5'-核苷酸酶水解。胰腺核糖核酸酶可使2',3'-环胞苷酸与阿洛尿苷形成(3'→6')-二核苷磷酸。它可被核酸酶S1切割，但不能被蛇毒磷酸二酯酶切割。它对多核苷酸磷酸化酶没有引物活性。无法通过核苷酸激酶或化学方法酶促制备阿洛尿苷6'-二磷酸，化学方法会形成5',6'-环磷酸酯，其仅水解为6'-单磷酸酯。
