- Oligonucleotide analogues with integrated bases and backbones. Part 25: Structural effects on the gelation of self-complementary A*[s]U dinucleosides
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The ability of A*[s]U dinucleosides to gel organic solvents and water is modulated by changing the nature of the substituents at O-C(2′) and O-C(3′), as evidenced by comparing the gelation of the dinucleosides 7-9 and the properties of the gels. A mere ex
- Bogliotti, Nicolas,Vasella, Andrea
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experimental part
p. 888 - 909
(2010/08/06)
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- ADENOSINE DEAMINASE INHIBITOR
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The present invention relates to adenosine deaminase inhibitors containing at least one O-alkylated moiety and the pharmaceutically acceptable salts thereof. The pharmaceutical compositions of the present invention include adenosine deaminase inhibitors containing at least one of the compounds represented by Formula (I): wherein each of R1, R2, and R3 are the same or different and is hydrogen or alkyl; R is hydrogen, alkyl, alkenyl, alkynyl, hydroxyalkynyl, alkoxy, phenyl, hydroxy, amino, alkylamino, phenylamino or halogen; X is hydrogen, alkyl, alkynyl, allyl, methallyl, cycloalkyl, alkyl having one or more hydroxy groups, phenyl, substituted phenyl, alkyl having one or more phenyl groups, alkyl having one or more substituted phenyl groups, bicycloalkyl, naphthylalkyl, acenaphthylenylalkyl or a compound represented by Formula (II) or Formula (III) wherein Z is hydrogen, hydroxy or lower alkoxy; Q is hydrogen or hydroxy; A is -CH2-, -O-, -S- or a mere linkage; Y is (CH2)n- or a mere linkage; n is an integer from 1 to 3; and any of R1, R2, and R3 is R3 lower alkyl
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- Methylation of Adenosine and Related Nucleosides with Trimethylselenonium Hydroxyde, and Regiospecific Effects of Copper(II) Ions
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Methylation of adenosine, deoxyadenosine, 6-N-methyladenosine and 2'(3')-O-methyladenosines with trimethylselenonium hydroxyde was studied in the presence and absence of copper(II) acetylacetonate .It was found that copper(II) ions promoted methylation of the 2'(3')-OH groups of the ribonucleosides but suppressed methylation at the N-1 position of the adenine rings.The metal-ion effects are discussed in conjunction with a catalytic role for Cu(AA)2 in the reactions.
- Yamauchi, Kiyoshi,Hattori, Kazue,Kinoshita, Masayoshi
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p. 1327 - 1330
(2007/10/02)
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- Methylation of Nucleosides with Trimethylsulfonium Hydroxide. Effects of Transition Metal Ions
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The effect of transition metal acetylacetonates on the methylation of ribo- and deoxyribonucleosides with trimethylsulfonium hydroxide was studied.With ribonucleosides the metal complexes promoted O'-methylation at the 2' and 3' positions of the ribosyl group.A comparable effect was not observed in methylation of deoxyribonucleosides.These results are attributed to an increase in the nucleophilicity of the 2'-OH and 3'-OH groups of the ribosides through complex formation with the metal ion; such a complex cannot form with the deoxyribose derivatives.The activity of the metal ions studied for promoting this O'-methylation increased in the order Mn2+ 2+ = Zn2+ 2+ 2+ 3+.These M(AA)n also suppressed N-methylation of the purine and pyrimidine rings of adenosine and cytidine.It is suggested that this result may be caused by coordination of the metal ions with ring nitrogens.
- Yamauchi, Kiyoshi,Nakagima, Toru,Kinoshita, Masayoshi
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p. 3865 - 3868
(2007/10/02)
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- Methylation study of ribonucleosides, deoxyribonucleosides, and 2′-O-methylribonucleosides with trimethylsulphonium hydroxide and trimethylsulphonium iodide. Influence of the 2′-hydroxy-groups on the reactivity of the base moieties of ribonucleosides
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Methylations of the naturally occuring ribonucleoside (1), deoxyribonucleoside (2), and 2′-O-methylribonucleoside (3) were carried out using trimethylsulphonium hydroxide (Me3SOH) and trimethylsulphonium iodide (Me3Sl). The base moiety of (2) and (3) are more reactive than the corresponding base moiety of (1). The sites and extent of methylation of (2) are considerably different from those of (1), but are almost identical with those of (3). The reactivities of (1)-(3) are discussed in connection to an intramolecular interaction of the 2′-OH groups with the base moiety of (1). The methylating characteristics of Me 3SOH and Me3Sl are also described. The kinetics indicate an SN2 mechanism for methylation of nucleosides by Me 3S+ ions.
- Yamauchi, Kiyoshi,Nakagima, Toru,Kinoshita, Masayoshi
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p. 2787 - 2792
(2007/10/02)
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