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Kanchugarakoppalu Subbegowda Rangappa - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of Nucleoside Derivatives, n-(benzoyl)-n-(deoxyguanosin-8-yl)4-aminobiphenyl and n-(2'-deoxyguanosin-8-yl)4-aminobiphenyl via alpha-phenyl-n-(4-biphenyl)nitrone.
Nucleosides Nucleotides & Nucleic Acids, 2002Co-Authors: H. Mallesha, K. R. Ravi Kumar, Kanchugarakoppalu Subbegowda RangappaAbstract:ABSTRACT Lead tetraacetate (LTA) oxidation of α-Phenyl-N-(4-biphenyl)nitrone (8) to give a new ultimate carcinogen, N-acetoxy-N-benzoyl-4-aminobiphenyl (9) which was reacted with deoxyguanosine (dG) at pH 6.9 to give Nucleoside Derivative, N-(benzoyl)-N-(deoxyguanosin-8-yl)-4-aminobiphenyl (10). Following debenzoylation with sodium carbonate-methanol leads to N-(2′-deoxyguanosin-8-yl)-4-aminobiphenyl (11).
Shigeki Sasaki - One of the best experts on this subject based on the ideXlab platform.
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2 6 diaminopurine Nucleoside Derivative of 9 ethyloxy 2 oxo 1 3 diazaphenoxazine 2 amino adap for recognition of 8 oxo dg in dna
Bioorganic & Medicinal Chemistry, 2014Co-Authors: Yosuke Taniguchi, Keitaro Fukabori, Yoshiya Kikukawa, Yohei Koga, Shigeki SasakiAbstract:Abstract 8-Oxo-2′-deoxyguanosine (8-oxo-dG) is a Nucleoside resulting from oxidative damage and is known to be mutagenic. 8-Oxo-dG has been related to aging and diseases, including neurological disorders and cancer. Recently, we reported that a fluorescent Nucleoside Derivative, adenosine-1,3-diazaphenoxazine (Adap), forms a stable base pair with 8-oxo-dG in DNA with accompanying efficient quenching. In this study, a new Adap Derivative having an additional 2-amino group on the adenosine moiety (2-amino-Adap) was designed with the anticipation of additional hydrogen bonding with the 8-oxo group of 8-oxo-dG. The properties of the ODN containing 2-amino-Adap were evaluated by measuring thermal stability and fluorescence quenching. In contrast to the previously designed Adap, the base-pairing and fluorescence quenching properties of 2-amino-Adap varied depending on the ODN sequence, and there was no clear indication of an additional hydrogen bond with 8-oxo-dG. Instead, the base pairing of 2-amino-Adap with dG was significantly destabilized compared with that of Adap with dG, resulting in improved selectivity for 8-oxo-dG in the human telomere DNA sequence. Thus, the telomere-targeting ODN probe containing 2-amino-Adap displayed selective, sensitive and quantitative detection of 8-oxo-dG in the human telomere DNA sequence in a light-up detection system using SYBR Green.
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Design and synthesis of the novel cross-linking reagents triggered by the triple helix formation
Nucleic Acids Symposium Series, 2000Co-Authors: Fumi Nagatsugi, Daisaku Usui, Takeshi Kawasaki, Minoru Maeda, Shigeki SasakiAbstract:In our attempt to new nucleobase analogs capable of interstrand cross-linking, we developed 2-amino-6vinyl purine analog (1). The oligonucleotides incorporating 1 showed efficient interstrand crosslinking with selectivity toward cytidine at a target site. In this paper, we describe the design of the new cross-linking reagents (2) bearing 2-amino-6-vinyl purine motif, and triplex-directed alkylation with 2 to double-stranded DNA. INTRODUCTION Sequence-specific triple helix formation is an attractive method for controlling gene expression by oligonucleotides. However, parallel-type triplexes formed with homopyrimidine oligonucleotides (TFOs) are not tight enough to strongly inhibit gene expression. In order to enhance the efficacy of TFOs, a number of improvements have been investigated. Interstrand covalent bond formation within triplex is expected to effect stability of triplexes, and a variety of reactive groups have been conjugated to TFOs. Recently, interesting applications of covalent modification to DNA have been reported, in which point mutation of the gene may be resulted at the site of reaction. Thus, alkylating agents will be useful for manipulation of gene expression, but existing methods still need further improvement in reactivity, selectivity as well as stability for possible application in living system. Fig. 1. Homo-PY Homo-PU Homo-PY We have previously reported that 2-amino-6vinylpurine nucleotide (1) exhibited efficient and selective cross-linking to cytidine within duplex. Further remarkable point of 1 is that the alkylation activity can be auto-generated within duplex from its stable precursors, phenylsulfide or phenylsulfbxide Derivatives. In this study, 2amino-6-vinylpurine motif was applied for crosslinking within triplexes, and the new Nucleoside Derivative (2) was designed. In the previous model study in organic solvents, 2-amino-6-vinylpurine motif reacted with N-7 of guanosine Derivative, bringing an idea that 1 would react with guanosine in a purine strand within the parallel triplex. On the other hand, the new Nucleoside Derivative 2 having an alkyl spacer between the sugar part and the 2-amino-6-vinylpurine motif would react with guanosine in pyrimidine strand at a far side of the TFO(Figl) . Scheme 1
Akira Matsuda - One of the best experts on this subject based on the ideXlab platform.
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synthesis and properties of a novel Nucleoside Derivative possessing a 2 3 5 6 tetraazabenzo cd azulene skeleton
Tetrahedron, 2010Co-Authors: Yasuyuki Hirama, Noriaki Minakawa, Akira MatsudaAbstract:Abstract We describe herein the synthesis and properties of the novel Nucleoside Derivative, 4,7-diamino-2-(2-deoxy-β- d -erythro-pentofuranosyl)-2,6-dihydro-7H-2,3,5,6-tetraazabenzo[cd]azulene (1). The palladium catalyzed cross-coupling reaction of 2,4-diamino-5-iodo-7-(2-deoxy-β- d -erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine (9) with acrylonitrile afforded 2,4-diamino-5-[(E)-1-cyano-2-ethenyl]-7-(2-deoxy-β- d -erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine (10) in 77% yield, which was treated with NaOMe in MeOH in the presence of NaSPh to give the desired 1 in 64% yield. Whereas 1 was stable in concentrated ammonia at room temperature, it was gradually hydrolyzed in water to give 4-amino-2-(2-deoxy-β- d -erythro-pentofuranosyl)-2,6-dihydro-7H-2,3,5,6-tetraazabenzo[cd]azulen-7-one (12). Density functional calculations indicated that 12 was 20 kcal/mol more thermodynamically stable than 1 in a model study.
H. Mallesha - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of Nucleoside Derivatives, n-(benzoyl)-n-(deoxyguanosin-8-yl)4-aminobiphenyl and n-(2'-deoxyguanosin-8-yl)4-aminobiphenyl via alpha-phenyl-n-(4-biphenyl)nitrone.
Nucleosides Nucleotides & Nucleic Acids, 2002Co-Authors: H. Mallesha, K. R. Ravi Kumar, Kanchugarakoppalu Subbegowda RangappaAbstract:ABSTRACT Lead tetraacetate (LTA) oxidation of α-Phenyl-N-(4-biphenyl)nitrone (8) to give a new ultimate carcinogen, N-acetoxy-N-benzoyl-4-aminobiphenyl (9) which was reacted with deoxyguanosine (dG) at pH 6.9 to give Nucleoside Derivative, N-(benzoyl)-N-(deoxyguanosin-8-yl)-4-aminobiphenyl (10). Following debenzoylation with sodium carbonate-methanol leads to N-(2′-deoxyguanosin-8-yl)-4-aminobiphenyl (11).
Yasuyuki Hirama - One of the best experts on this subject based on the ideXlab platform.
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synthesis and properties of a novel Nucleoside Derivative possessing a 2 3 5 6 tetraazabenzo cd azulene skeleton
Tetrahedron, 2010Co-Authors: Yasuyuki Hirama, Noriaki Minakawa, Akira MatsudaAbstract:Abstract We describe herein the synthesis and properties of the novel Nucleoside Derivative, 4,7-diamino-2-(2-deoxy-β- d -erythro-pentofuranosyl)-2,6-dihydro-7H-2,3,5,6-tetraazabenzo[cd]azulene (1). The palladium catalyzed cross-coupling reaction of 2,4-diamino-5-iodo-7-(2-deoxy-β- d -erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine (9) with acrylonitrile afforded 2,4-diamino-5-[(E)-1-cyano-2-ethenyl]-7-(2-deoxy-β- d -erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine (10) in 77% yield, which was treated with NaOMe in MeOH in the presence of NaSPh to give the desired 1 in 64% yield. Whereas 1 was stable in concentrated ammonia at room temperature, it was gradually hydrolyzed in water to give 4-amino-2-(2-deoxy-β- d -erythro-pentofuranosyl)-2,6-dihydro-7H-2,3,5,6-tetraazabenzo[cd]azulen-7-one (12). Density functional calculations indicated that 12 was 20 kcal/mol more thermodynamically stable than 1 in a model study.
