Desulfurization of 2-thiouracil nucleosides: Conformational studies of 4-pyrimidinone nucleosides
摘要:
4-Pyrimidinone ribofuranoside (H(2)o(4)U) and 4-pyrimidinone 2 '-deoxyribofuranoside (dH(2)o(4)U) were synthesized by the oxidative desulfurization of parent 2-thiouracil nucleosides with m-chloroperbenzoic acid. The crystal structures of H(2)o(4)U and dH(2)o(4)U and their conformations in solution were determined and compared with corresponding 2-thiouracil and uracil nucleosides. The absence of a large 2-thiocarbonyl/2-carbonyl group in the nucleobase moiety results in C2'-endo puckering of the ribofuranose ring (S conformer) in the crystal structure of H(2)o(4)U, which is not typical of RNA nucleosides. Interestingly, the hydrogen bonding network in the crystals of dH(2)o(4)U stabilizes the sugar moiety conformation in the C3'-endo form (N conformer), rarely found in DNA nucleosides. In aqueous solution, dH(2)o(4)U reveals a similar population of the C2'-endo conformation (65%) to that of 2'-deoxy-2-thiouridine (62%), while the 62% population of the S conformer for H(2)o(4)U is significantly different from that of the parent 2-thiouridine, for which the N conformer is dominant (71%). Such a difference may be of biological importance, as the desulfurization process of natural tRNA 2-thiouridines may occur under conditions of oxidative stress in the cell and may influence the decoding process. (C) 2011 Elsevier Ltd. All rights reserved.
用反式-2-苯基磺酰基-3-苯基恶唑烷酮(PSO)对2-硫代嘧啶核苷(s 2 U ∗)进行简短处理,可以有效地进行底物脱硫,从而生成相应的4-嘧啶酮酮类似物(H 2 U ∗)。关键的转化过程是通过将2-硫代羰基氧化为硫代含氧酸衍生物,然后消除二氧化硫而进行的。4-嘧啶酮1-β-d-核糖苷(H 2U)已转化为相应的亚磷酰胺,这是一种随时可用的单体,用于将修饰的核苷引入寡核苷酸链。而且,如MALDI-TOF质谱法所证实的,通过用PSO处理TdA(s 2 U)dGdC寡核苷酸,可以直接在寡核苷酸水平上实现2-硫尿苷核苷酸的有效脱硫。
and convenient method for the synthesis of several pyrimidine and purine nucleosides by selective oxidation of thionucleosides with dimethyldioxirane is reported. Thioketo moieties in the C-4 position of the pyrimidine ring, and in the C-6, and C-8 positions of the purine ring are the domain of oxidative nucleophilic substitution. Thioketo moieties in the C-2 position of both purine and pyrimidine rings
Improved synthesis of oligonucleotides containing 2-thiouridine derivatives by use of diluted iodine solution
作者:Itaru Okamoto、Kohji Seio、Mitsuo Sekine
DOI:10.1016/j.tetlet.2005.11.044
日期:2006.1
2-thiocarbonyl group of 2-thiouridine (s2U) derivatives reacts easily with various oxidizing agents used in oligonucleotidesynthesis to give a complex mixture. In this letter, we report an improved method for the synthesis of oligonucleotidescontaining s2U derivatives. It turned out that the 2-thiocarbonyl group of oligonucleotidescontaining s2U derivatives was stable in a 0.02 M solution of iodine
Novel nucleoside analogs, such as 3-(&bgr;-D-Ribofuranosyl)-2-fluoropyridine, 3-(&bgr;-D-Ribofuranosyl)-pyridin-2-one, 3-(&bgr;-D-Ribofuranosyl)-pyridin-2-(4-nitrophenylethyl)-one, 3-(&agr;-D-Ribofuranosyl)-2-fluoropyridine, 5-(&bgr;-D-Ribofuranosyl)-2-bromopyridine, 5-(&agr;-D-Ribofuranosyl)-2-bromopyridine, 5-(&bgr;-D-Ribofuranosyl)-pyridin-2-one, 5-(&agr;-D-Ribofuranosyl)-pyridin-2-one, 5-(&bgr;-D-Ribofuranosyl)-2-aminopyridine, 5-(&bgr;-D-Ribofuranosyl)-pyridin-2-(4-nitrophenylethyl)-one, and 5-(&agr;-D-Ribofuranosyl)-2-aminopyridine; process for their synthesis and incorporation into polynucleotides.
Process for the production of 3'-nucleoside prodrugs
申请人:——
公开号:US20040181051A1
公开(公告)日:2004-09-16
Provided is a single-step process for the selective 3′-acylation of a ribofuranosyl 2′ or 3′-branched nucleoside. These compounds are useful as antiviral agents, and in particular, can be used to treat Flaviviridae infections in a host in need thereof.