The dideoxy chain termination method using deoxy-7-deaza-guanosine triphosphate (dc 7 GTP)in place of dGTP was found to be very useful. Sequencing a part the human N- myc gene having 85% GC content is impossible by original dGTP, because compression bands. However, nucleotide sequence this unambiguously determined analysis both strands modified method. Use dc GTP concluded improve for DNA sequencing.

A new, easy-to-prepare and highly selective pyrene-linked tris-triazole amine fluorescent chemosensor has been designed from tripropargylamine pyrene azide using Cu(I)-catalyzed click chemistry. The fluorescence on-off sensor 1 is for Zn(2+) displaying a ratiometric change in emission. relative intensity ratio of monomer to excimer (M(376)/E(465)) the increases 80-fold upon addition 10 equiv ions (with detection limit 0.2 μM).

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSyn-anti conformational analysis of regular and modified nucleosides by 1D 1H NOE difference spectroscopy: a simple graphical method based on conformationally rigid moleculesHelmut Rosemeyer, Gabor Toth, Bozenna Golankiewicz, Zygmunt Kazimierczuk, Werner Bourgeois, Uwe Kretschmer, Heinz Peter Muth, Frank SeelaCite this: J. Org. Chem. 1990, 55, 22, 5784–5790Publication Date (Print):October 1, 1990Publication History Published online1 May...

Oligonucleotides incorporating 5-(octa-1,7-diynyl)-2′-deoxycytidine 1a, 5-(octa-1,7-diynyl)-2′-deoxyuridine 2a and 7-deaza-7-(octa-1,7-diynyl)-2′-deoxyguanosine 3a, 7-deaza-7-(octa-1,7-diynyl)-2′-deoxyadenosine 4a were prepared. For this, the phosphoramidites 7, 10, 13 synthesized employed in solid-phase oligonucleotide synthesis. The octa-1,7-diynyl nucleosides 1a−4a obtained from their corresponding iodo derivatives using palladium-assisted Sonogashira cross-coupling reaction. Tm values...

Abstract Oligonucleotides constructed of 1′, 5′‐anhydrohexitol nucleoside building blocks (hexitol nucleic acids, HNA) are completely stable towards 3′‐exonuclease and form very self‐complementary duplexes as well sequence‐selective with the natural DNA RNA. Triple‐helix formation has also been observed. These hybridisation characteristics highly dependent on base sequence experimental conditions. When using a phosphate buffer containing 0.1M NaCl, homopurine HNA dodecamer gives δ T m +3.0...

The replacement of the furanose moiety DNA by a cyclohexene ring gives new nucleic acid structure:  acids or CeNA. CeNAs can be obtained classical phosphoramidite ch...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of 2-amino-7-(2'-deoxy-.beta.-D-erythro-pentofuranosyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one, a new isostere 2'-deoxyguanosineHeinz Dieter Winkeler and Frank SeelaCite this: J. Org. Chem. 1983, 48, 18, 3119–3122Publication Date (Print):September 1, 1983Publication History Published online1 May 2002Published inissue 1 September 1983https://pubs.acs.org/doi/10.1021/jo00166a043https://doi.org/10.1021/jo00166a043research-articleACS...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIncorporation of a complete set deoxyadenosine and thymidine analogs suitable for the study protein nucleic acid interactions into oligodeoxynucleotides. Application to EcoRV restriction endonuclease modification methylasePatrick C. Newman, Victor U. Nwosu, David M. Williams, Richard Cosstick, Frank Seela, Bernard A. ConnollyCite this: Biochemistry 1990, 29, 42, 9891–9901Publication Date (Print):October 1, 1990Publication History Published online1...

The 7-tripropargylamine-7-deaza-2′-deoxyguanosine (2) containing two terminal triple bonds in the side chain was synthesized by Sonogashira cross-coupling reaction from corresponding 7-iodo nucleoside 1b. This protected at 2-amino group with an iso-butyryl residue, affording intermediate 5. Then, compound 5 converted to 5′-O-DMT derivative 6, which on phosphitylation afforded phosphoramidite 7. employed solid-phase synthesis of a series oligonucleotides. Tm measurements demonstrate that...

5-(Octa-1,7-diynyl)-2′-deoxyuridine was converted into the furano-dU derivative 7 by copper-catalyzed cyclization; pyrolodC-derivative 3 formed upon ammonolysis. The bicyclic nucleosides and as well corresponding non-cyclic precursors 4 6 all containing terminal CC bonds were conjugated with non-fluorescent 3-azido-7-hydroxycoumarin 5 employing copper(I)-catalyzed Huisgen–Sharpless–Meldal cycloaddition "click reaction". Strongly fluorescent 1H-1,2,3-triazole conjugates (30–33) are...

Abstract Oligonucleotides containing the 5‐substituted 2′‐deoxyuridines 1b or 1d bearing side chains with terminal CC bonds are described, and their duplex stability is compared oligonucleotides 5‐alkynyl compounds 1a 1c only one nonterminal bond in chain. For this, 5‐iodo‐2′‐deoxyuridine ( 3 ) diynes alkynes were employed as starting materials Sonogashira cross‐coupling reaction Scheme 1 ). Phosphoramidites 2b – d prepared used building blocks solid‐phase synthesis. T m Measurements...

Abstract Nucleobase‐directed spin‐labeling by the azide‐alkyne ‘click’ (CuAAC) reaction has been performed for first time with oligonucleotides. 7‐Deaza‐7‐ethynyl‐2′‐deoxyadenosine ( 1 ) and 5‐ethynyl‐2′‐deoxyuridine 2 were chosen to incorporate terminal triple bonds into DNA. Oligonucleotides containing or synthesized on a solid phase spin labeling 4‐azido‐2,2,6,6‐tetramethylpiperidine 1‐oxyl (4‐azido‐TEMPO, 3 was post‐modification in solution. Two labels incorporated high efficiency DNA...

6-Substituted pyrrolo-dC-pyrrolo-dC mismatches selectively capture silver ions to form extraordinarily stable metal-mediated base pairs. One single modification in a 12-mer duplex causes Tm increase of 36.0 °C relative the metal-free mismatched duplex. Spectrophotometric titrations as well ESI mass spectra confirmed binding two per pair. The Ag(+)-mediated pairs may permit construction metal-responsive DNA with very high loading.

The silver-mediated imidazolo-dC base pair decorated with a furan residue forms exceptionally stable dinuclear silver bridges in DNA double helices parallel and antiparallel chain orientation.

Abstract Reverse Watson–Crick DNA with parallel‐strand orientation (ps DNA) has been constructed. Pyrrolo‐dC (PyrdC) nucleosides phenyl and pyridinyl residues linked to the 6 position of pyrrolo[2,3‐ d ]pyrimidine base have incorporated in 12‐ 25‐mer oligonucleotide duplexes utilized as silver‐ion binding sites. Thermal‐stability studies on parallel strands demonstrated extremely strong strongly enhanced duplex stability. Stoichiometric UV fluorescence titration experiments verified that a...

Abstract The synthesis of a series oligonucleotides containing 5‐substituted pyrimidines as well 7‐substituted 7‐deazapurines bearing diyne groups with terminal triple bonds is reported. modified nucleosides were prepared from the corresponding iodo and diynes by Sonogashira cross‐coupling reaction. They converted into phosphoramidites employed in solid‐phase oligonucleotides. effect modifications on duplex stability was investigated. used for further functionalization using protocol...

Abstract The anomeric configuration of D-ribo-, D-arabi-no, D-2′-deoxyribo-, and D-2′,3′-dideoxyribonucleosides was assigned unambiguously applying n.O.e. difference spectros-copy. For this purpose 1′-H, signals were saturated the factors 4′-H, 3′-H, 2′-H measured.

Octadeoxynucleotides with the sequence d[(p)GG*AATTCC] have been prepared by solid-phase synthesis employing regular and base-modified phosphoramidites. These oligomers which contain an isosterically altered recognition of endodeoxyribo-nuclease Eco RI form duplexes under appropriate salt conditions. Since G* can represent 7-deaza-2'-deoxyguanosine were used as probes to study their cleavage endodeoxyribonuclease RI. The enzymatic hydrolysis modified octamer was strongly decreased compared...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPalindromic octa- and dodecanucleotides containing 2'-deoxytubercidin: synthesis, hairpin formation, recognition by the endodeoxyribonuclease EcoRIFrank Seela Andreas KehneCite this: Biochemistry 1987, 26, 8, 2232–2238Publication Date (Print):April 1, 1987Publication History Published online1 May 2002Published inissue 1 April 1987https://pubs.acs.org/doi/10.1021/bi00382a024https://doi.org/10.1021/bi00382a024research-articleACS PublicationsRequest...

The internal dye labeling of DNA by the Huisgen-Meldal-Sharpless "click" reaction is described. Fluorogenic 9-azidomethyl anthracene 2 and 3-azido-7-hydroxycoumarin 3 were employed in postsynthetic functionalization oligonucleotides incorporating octa-(1,7)-diynyl-8-aza-7-deaza-2′-deoxyadenosine 1. Nucleoside 1 was prepared Sonogashira cross coupling from corresponding 7-iodo compound, converted into phosphoramidite, synthesized. To evaluate influence ligands on oligonucleotide duplex...

8-Aza-2′-deoxyisoguanosine (4) is the first fluorescent shape mimic of 2′-deoxyisoguanosine (1a); its fluorescence stronger in alkaline medium than under neutral conditions. Nucleoside 4, which was synthesized from 8-aza-2′-deoxyguanosine via a 4,6-diamino intermediate after selective deamination, incorporated oligodeoxyribonucleotides using phosphoramidite 11. Duplexes with 4·m5iCd (5-methyl-2′-deoxyisocytidine) base pairs are more stable those incorporating dG-dC pairs, thereby expanding...

Cross-linked DNA was constructed by a "stepwise click" reaction using bis-azide. The is performed in the absence of template, and monofunctionalized oligonucleotide bearing an azido-function formed as intermediate. For this, excess bis-azide has to be used compared alkynylated oligonucleotide. cross-linking can carried out with any having terminal triple bond at position oligonucleotide, independent chain length or sequence identical nonidentical chains. Short long linkers bonds were...

Abstract 8‐Phenylimidazolo‐dC ( ph ImidC, 2 ) forms metal‐mediated DNA base pairs by entrapping two silver ions. To this end, the fluorescent “purine” 2′‐deoxyribonucleoside has been synthesised and converted into phosphoramidite 6 . Owing to ease of nucleobase deprotonation, new Ag + ‐mediated pair containing a skeleton is much stronger than that derived from pyrrolo‐ [3,4‐ d ]pyrimidine system PyrdC, 1 ). The silver‐mediated ImidC– ImidC fits well double helix stability covalent...