Cosstick R, Vyle J S
Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, UK.
Nucleic Acids Res. 1990 Feb 25;18(4):829-35. doi: 10.1093/nar/18.4.829.
Dithymidine-3'-S-phosphorothioate (d(TspT)) has been prepared from a 5'-O-monomethoxytritylthymidine-3'-S-phosphorothioamidite (7) by activation with 5-(p-nitrophenyl)tetrazole in the presence of 3'-O-acetylthymidine. The resulting dinucleoside phosphorothioite is readily oxidised to the corresponding 3'-S-phosphorothioate using either tetrabutylammonium (TBA) periodate or TBA oxone and has been deprotected under standard conditions to yield d(TspT). This dithymidine phosphate analogue is comparatively resistant to hydrolysis by nuclease P1, but the P-S bond is readily cleaved by aqueous solutions of either iodine or silver nitrate. Dithymidine-3'-S-phosphorodithioate (d[Tsp(s)T]) was prepared in an analogous fashion using sulphur to oxidise the intermediate dinucleoside phosphorothioite. Absolute stereochemistry has been assigned to the diastereoisomers of d[Tsp(s)T] by comparing their physical and chemical properties to those of the dinucleoside phosphorothioates.
3'-硫代磷酸二胸苷(d(TspT))由5'-O-单甲氧基三苯甲基胸苷-3'-硫代磷酰胺亚基(7)在3'-O-乙酰胸苷存在下用5-(对硝基苯基)四唑活化制备而成。所得的二核苷硫代磷酸酯用四丁基铵(TBA)高碘酸盐或TBA过氧单磺酸钾很容易氧化为相应的3'-硫代磷酸酯,并在标准条件下脱保护得到d(TspT)。这种磷酸二胸苷类似物相对耐核酸酶P1水解,但P-S键很容易被碘或硝酸银水溶液裂解。3'-二硫代磷酸二胸苷(d[Tsp(s)T])以类似方式制备,使用硫氧化中间的二核苷硫代磷酸酯。通过将d[Tsp(s)T]的非对映异构体的物理和化学性质与二核苷硫代磷酸酯的性质进行比较,确定了其绝对立体化学结构。