The modified nucleosides of tRNAs. II. Synthesis of 2′-O-methylcytidylyl (3′-5′) cytidine

Markiewicz, Wojciech T.; Wiewiórowski, M.

doi:10.1093/nar/2.6.951

Cited by 11 publications

(7 citation statements)

References 12 publications

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“…The desired β ‐isomer 6 could be isolated from this mixture by crystallization 62, 63. Cleavage of the acetonide protection group and subsequent reaction of 7 with 1,3‐dichloro‐1,1,3,3‐tetradiisopropyldisiloxane64, 65 provided the key intermediate 8 . Esterification of the free 2′‐hydroxyl group with 3‐trifluoromethyl benzoyl chloride to allow future photodeoxygenation, furnished the nitropyrimidine ribofuranoside 9 .…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Stability, and Conformation of the Formamidopyrimidine G DNA Lesion

Burgdorf

Carell

2002

Chem. Eur. J.

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The formamidopyrimidine (FapydGua) lesion, derived from the nucleobase guanine, is a major DNA lesion involved in mutagenesis and carcinogenesis. To date, the chemical information available about this main lesion is very limited. Herein, we describe a synthesis and a detailed characterization of the acetyl-protected monomer of the FapydGua lesion. Stability studies in DMSO and in water/acetonitrile show that the N-glycosidic bond, previously thought to be highly labile, is much more stable than anticipated. Decomposition of the FapydGua lesion proceeds with half-life times of 37.8 h for the beta-anomer and 65.2 h for the alpha-anomer in water/acetonitrile. The relaxation time for the anomerization reaction was determined to tau = 6.5 h at room temperature. Most important, it was found that the formamido group, which is critical for the lesion recognition process by repair enzymes, is fixed in the cis-conformation in apolar solvents such as chloroform. This conformation enables the formation of a hydrogen bond between the carbonyl oxygen of the formamide and the NH of the N-glycosidic bond within the framework of a seven-membered ring system. This has consequences for the recognition of the lesion by repair enzymes (hOGG1 and Fpg protein). These enzymes were so far believed to recognize the carbonyl group of the FapydGua lesion. Our investigations show that this carbonyl group is not readily accessible because it is almost buried in the dominating cis-conformation. In agreement with the recent X-ray structure of hOGG1 in complex with 8-oxo-7,8-dihydroguanine-containing DNA, we can conclude that repair enzymes can contact both lesions only via the N(7)-H group, which is a hydrogen-bond acceptor in guanine.

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Section: Resultsmentioning

confidence: 99%

Synthesis, Stability, and Conformation of the Formamidopyrimidine G DNA Lesion

Burgdorf

Carell

2002

Chem. Eur. J.

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“…18 We also attempted to manipulate position 2′ utilizing compound 4a, which we were able to produce in gram quantities by the routes depicted in Schemes 4 and 5 above. Standard diprotection of 5′-and 3′-hydroxyls by TIPDS 19 provided cyclic siloxane 29 (Scheme 7). Alkylation of the remaining free hydroxyl at position 2′ followed by final deprotection yielded target compound 30, whose structural integrity was confirmed by X-ray crystallography (see the Supporting Information).…”

Section: ■ Results and Discussionmentioning

confidence: 93%

“…The organic extracts were dried over Na 2 SO 4 , evaporated, and the residue was purified by flash chromatography to afford the product. tert-Butyl(((3aR*,4R*,6aS*)-2,2-dimethyl-6-phenyl-4,6a-dihydro-3aH-cyclopenta [d][1,3]dioxol-4-yl)methoxy)diphenylsilane (19). The compound was prepared by General Procedure E using enol triflate 18a (440 mg, 0.79 mmol) and PhB(OH) 2 (145 mg, 1.18 mmol); flash chromatography (hexane/EtOAc = 20:1) afforded 19 as a colorless oil (326 mg, 85%).…”

Section: The Journal Of Organic Chemistrymentioning

confidence: 99%

“…0, 49.4, 39.1, 27.4, 18.5, 18.44, 18.41, 17.9, 13.7, 13.3, 12.5 ppm. 19 ((1R* ,4S* ,5R*)-3-(1-Methyl-1H-pyrazol-4-yl)-4,5-bis-(triisopropylsilyloxy)cyclopent-2-enyl)methyl Pivalate (21c). The compound was prepared by General Procedure E using triflate 18b (575 mg, 0.85 mmol) and 1-methylpyrazole-4-boronic acid pinacol ester (194 mg, 0.94 mmol); flash chromatography (hexane/EtOAc = 20:1) afforded 21c as a colorless wax (450 mg, 87%).…”

Section: The Journal Of Organic Chemistrymentioning

confidence: 99%

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Diastereoselective Flexible Synthesis of Carbocyclic C-Nucleosides

et al. 2017

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Carbocyclic C-nucleosides are quite rare. Our route enables flexible preparation of three classes of these nucleoside analogs from common precursors-properly substituted cyclopentanones, which can be prepared racemic (in six steps) or optically pure (in ten steps) from inexpensive norbornadiene. The methodology allows flexible manipulation of individual positions around the cyclopentane ring, namely highly diastereoselective installation of carbo- and heterocyclic substituents at position 1', orthogonal functionalization of position 5', and efficient inversion of stereochemistry at position 2'. Newly prepared carbocyclic C-analog of tubercidine, profiled in MCF7 (breast cancer) and HFF1 (human foreskin fibroblasts) cell cultures, is less potent than tubercidine itself, but more selectively toxic toward the tumorigenic cells.

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“…The 1-(2-chloroethoxy) ethyl group recently described by Takaku (41) probably behaves similarly to Mthp. An obvious advantage of 2'-acetal protecting groups is that exclusively 2'-O-derivatives can be prepared via the use of 3' ,5'-O-(tetraisopropyldisiloxane-1 ,3-diyl) protected ribonucleosides (42). The Ctmp group has been successfully applied by Reese et al in solid phase synthesis by the (3-cyanoethyl phosphoramidite procedure (43) and the H-phosphonate procedure (44), the latter method giving an 8% isolated yield of an 18 mer.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and applications of oligoribonucleotides with selected 2′-O-methylation using the 2′-O-[1-(2-fluorophenyl)-4-methoxypiperidin-4-yl] protecting group

Beijer¹,

Sulston²,

Sproat³

et al. 1990

Nucl Acids Res

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The synthesis of base protected 5'-O-dimethoxytrityl-2'-O-[1-(2- fluorophenyl)-4-methoxypiperidin-4-yl]-3'-O-(2-cyanoethyl N,N-diisopropylphosphoramidites) is described, using phenoxyacetyl protection for the exocyclic amino groups of guanosine and adenosine and acetyl protection of the amino group of cytidine. High yield assembly of these building blocks into oligoribonucleotides on aminopropyl controlled pore glass was achieved using 5-(4-nitrophenyl)-1H-tetrazole as activator. Mixed sequences containing selected 2'-O-methylation were also synthesised and their significance for the study of RNA biochemistry is discussed.

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The modified nucleosides of tRNAs. II. Synthesis of 2^′-O-methylcytidylyl (3^′-5^′) cytidine

Cited by 11 publications

References 12 publications

Synthesis, Stability, and Conformation of the Formamidopyrimidine G DNA Lesion

Synthesis, Stability, and Conformation of the Formamidopyrimidine G DNA Lesion

Diastereoselective Flexible Synthesis of Carbocyclic C-Nucleosides

Synthesis and applications of oligoribonucleotides with selected 2′-O-methylation using the 2′-O-[1-(2-fluorophenyl)-4-methoxypiperidin-4-yl] protecting group

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