structure in a 16-memberedmacrocyclic ring together with benzoxazolinate and aminosugar moieties as side chains7~9) (Fig. 1). The biological activity of the chromophore has been attributed to its ability to produce DNA damage following rearrangement to form a diradical species which abstracts hydrogen atoms from deoxyribose even in the absence of reducing agent10~ 12), in contrast to other ened...

A facile and general procedure for the preparation of alkynyl C-nucleosides with varied fluorophores is presented. Sonogashira coupling was used as a key reaction to conjugate the dyes to an easily accessible ethynyl functionalized deoxyribose derivative. The new C-nucleosides were used for the preparation of DNA-based polyfluorophores.

The oligonucleotide [5'-32P]pdT8d(-)dT., containing an apurinic/apyrimidinic (AP) site [d(-)], yields three radioactive products when incubated at alkaline pH: two of them, forming a doublet approximately at the level of pdT8dA when analysed by polyacrylamide-gel electrophoresis, are the result of the f-elimination reaction, whereas the third is pdT8p resulting from ,8-elimination. The incubati...

The side effects of synthetic antioxidants have been considered in different studies. Accordingly, there is an increasing interest toward the use of natural substances instead of the synthetic ones. In this study, the aqueous and ethanolic extracts of Pistacia vera leaves and fruits as well as hydroalcoholic extract of gum were tested for a possible antioxidant activity using in vitro methods. ...

7-Hydroxyguanine, an antitumor purine-analog, reacted with ribose (or deoxyribose)-1-phosphate in the presence of purine nucleoside phosphorylase. We prepared 7-hydroxyguanine riboside and deoxyriboside using purine nucleoside phosphorylase from bovine spleen. Each nucleoside exhibits antitumor activity against mouse leukemia L1210 cells. The therapeutic effect of 7-hydroxyguanine deoxyriboside...

1H-1H and 31P-1H nuclear Overhauser effects and 31P NMR spin-lattice relaxation times were measured for a synthetic DNA poly(dA-dT).poly(dA-dT) in a low-salt aqueous solution. The results have shown that all bases in the double helix are anti-orientated with respect to deoxyribose residues and that the sugar-phosphate backbone has an alternating architecture.

A wide range of cytotoxic and mutagenic DNA bases are removed by different DNA glycosylases, which initiate the base excision repair pathway. DNA glycosylases cleave the N-glycosylic bond between the target base and deoxyribose, thus releasing a free base and leaving an apurinic/apyrimidinic (AP) site. In addition, several DNA glycosylases are bifunctional, since they also display a lyase activ...

Topical microbicides may prove to be an important strategy for preventing human immunodeficiency virus type 1 (HIV-1) transmission. We examined the safety and efficacy of sequence-nonspecific phosphorothioate 2' deoxyribose oligomers as potential novel microbicides. A short, 13-mer poly(T) phosphorothioate oligodeoxynucleotide (OPB-T) significantly inhibited infection of primary peripheral bloo...