Biomedical subjects

Kuiying Xu

Publications and source records attributed to Kuiying Xu.

5 recordsLinked to original sources

PubMed2005

2'-Deoxy-5-fluorotubercidin.

In the title compound, 4-amino-7-(2-deoxy-beta-D-erythro-pentofuranosyl)-5-fluoro-7H-pyrrolo[2,3-d]pyrimidine, C11H13FN4O3, the conformation of the glycosyl bond lies between anti and high anti [chi = -101.1 (3) degrees ]. The furanose moiety adopts the S-type sugar pucker (2T3), with P = 164.7 (3) degrees and tau = 40.1 (2) degrees . The extended structure is a three-dimensional hydrogen-bond network involving a C-H...F, two N-H...O and two O-H...O hydrogen bonds.

Crystallography, X-Ray↗

PubMed2005

8-Aza-7-deaza-7-propynyladenosine methanol solvate.

In the title compound, 4-amino-3-propynyl-1-(beta-D-ribofuranosyl)-1H-pyrazolo[3,4-d]pyrimidine methanol solvate, C13H15N5O4.CH3OH, the torsion angle of the N-glycosylic bond is between anti and high-anti [chi = -101.8 (5) degrees ]. The ribofuranose moiety adopts the C3'-endo (3T2) sugar conformation (N-type) and the conformation at the exocyclic C-C bond is +sc (gauche, gauche). The propynyl group is out of the plane of the nucleobase and is bent. The compound forms a three-dimensional network which is stabilized by several hydrogen bonds (O-H...O and O-H...N). The nucleobases are stacked head-to-tail. The methanol solvent molecule forms hydrogen bonds with both the nucleobase and the sugar moiety.

Adenosine↗

PubMed2005

6-azapyrimidine and 7-deazapurine 2'-deoxy-2'-fluoroarabinonucleosides: synthesis, conformation and properties of oligonucleotides.

The synthesis of 2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl nucleosides (1b, 2b, and 3b) were described and their conformation in solution as well as in the solid state was determined In addition to this, building blocks 10a,b and 13a,b were prepared and employed in solid-phase oligonucleotide synthesis. For compounds 1a and 1b the lactime proton is protected to avoid unresolved degradation of its phosphoramidites 10a,b. UV-melting studies have been carried out to assess the thermal stability of oligonucleotides containing compounds 1a,b, and 3a,b.

Arabinonucleosides↗

PubMed2005

7-substituted 8-aza-7-deazapurines and 2,8-diaza-7-deaza-purines: synthesis of nucleosides and oligonucleotides.

7-Substituted 8-aza- 7-deazaadenosines 1a-e were synthesized by Sonogashira cross coupling from the corresponding 7-iodo nucleoside in 36-79% yields. Starting from 7-bromo (or 7-iodo)-8-aza-7-deazaadenine, 2a,b were obtained by acid-catalyzed glycosylation followed by deprotection in 53 and 35% yields, repectively. Compounds 2b was applied to cross coupling reaction to give 2c-d in 34-95% yield. Compounds 2a and 4b were further transformed to the phosphoramidites 5 and 6b in 9 and 49% overall yields, which were incorporated into oligonucleotides.

Catalysis↗

PubMed2004

7-Vinyl-8-aza-7-deaza-2'-deoxyadenosine monohydrate.

In the title compound, 4-amino-1-(2-deoxy-beta-D-eythro-pentofuranosyl)-3-vinyl-1H-pyrazolo[3,4-d]pyrimidine monohydrate, C12H15N5O3.H2O, the conformation of the glycosyl bond is anti. The furanose moiety is in an S conformation with an unsymmetrical twist, and the conformation at the exocyclic C-C(OH) bond is +sc (gauche, gauche). The vinyl side chain is bent out of the heterocyclic ring plane by 147.5 (5) degrees . The three-dimensional packing is stabilized by O-H...O, O-H...N and N-H...O hydrogen bonds.

Aza Compounds↗