Synthesis of Azacyclic Nucleoside Analogues via Asymmetric [3 + 2] Cycloaddition of 9-(2-Tosylvinyl)-9H-purines.

With 9-(2-tosylvinyl)-9H-purines as the dipolarophiles, a series of chiral azacyclic nucleosides with four continuous stereocenters were obtained in 86-99% yields, >20:1 dr, and 94 → 99% ee via the Cu(I)-catalyzed asymmetric [3 + 2] cycloaddition. Both (E)- and (Z)-9-(2-tosylvinyl)-9H-purines were suitable dipolarophiles, enriching the structure diversity of azacyclic nucleosides. Furthermore, when α-methyl imino ester was explored, the corresponding azacyclic nucleoside with a chiral quaternary stereocenter could also be afforded with excellent results.

A rapid and divergent access to chiral azacyclic nucleoside analogues via highly enantioselective 1,3-dipolar cycloaddition of β-nucleobase substituted acrylates.

A rapid and divergent access to chiral azacyclic nucleoside analogues has been established via highly exo-selective and enantioselective 1,3-dipolar cycloaddition of azomethine ylides with β-nucleobase substituted acrylates. Using 1 mol% of a chiral copper complex, various chiral azacyclic nucleoside analogues were obtained in high yields, excellent exo-selectivities and enantioselectivities (98 to >99% ee).

[Association between polymorphisms of interleukin-6 gene promoter and breast cancer].

Aim: To study possible association between three single nucleotide polymorphisms (-597G/A, -572C/G and -174G/C) of interleukin-6 (IL-6) gene promoter and breast cancer.

Methods: Genomic DNA was isolated from the venous blood leukocytes from 176 unrelated patients with breast cancer and 200 healthy unrelated females (control group). Polymorphisms of -597G/A, -572C/G and -174G/C, were genotyped by PCR-restriction fragment length polymorphisms (PCR-RFLP).

Overexpression of Nampt in gastric cancer and chemopotentiating effects of the Nampt inhibitor FK866 in combination with fluorouracil.

Nicotinamide phosphoribosyltransferase (Nampt), an enzyme involved in the NAD⁺ salvage pathway, is over-expressed and important in the carcinogenesis in several types of cancers. The expression of Nampt and its role in gastric cancer remain largely unknown. In this study, using real-time PCR and Western blotting we found that Nampt was overexpressed at the mRNA and protein levels, respectively, in established gastric cancer cells and human gastric cancer tissues.